HK1153446A1 - Elevator system - Google Patents

Abstract

The present invention provides an elevator system which calculates an energy storage amount of an energy storage device (1) in future. When a calculated value VB' of the energy storage amount in future exceeds a preset value, energy stored in the energy storage device (11) is discharged. Furthermore at least one part of the discharged energy is consumed in an elevator cage lighting device (17) and a control device (12). In the elevator system, increasing of the energy storage capacity of the energy storage device is not required. Even when the energy storage amount is increased because of sudden increase of regenerated power, the regenerated power can be effectively used.

Description

Elevator system

Technical Field

The present invention relates to an elevator system, and more particularly, to an elevator system capable of effectively utilizing regenerative power by an energy storage device (energy accumulation device) such as a battery.

Background

In a conventional elevator system of a medium-low speed level, when a motor performs a regenerative operation (regenerative operation), that is, when position energy is converted into electric energy, regenerative electric power generated by the motor is consumed by a resistor. In contrast, in order to achieve energy saving, research and development have been conducted on elevator systems that utilize a rechargeable battery (also referred to as a secondary battery), store electric power such as regenerative electric power in the battery, and discharge electric power from the battery to the motor side when necessary.

In the above-described elevator system, for example, in the first half of the lunch time and the next working hours in an office building or the like, and the working hours in a collective housing or an apartment house, it is necessary to repeat the full-load down operation and the empty load up operation, and in this case, since the regenerative operation is continuously performed, if the storage capacity of the storage battery is small, the empty capacity of the storage battery becomes insufficient, and there is a problem that the regenerative power generated after the storage battery is sufficiently charged cannot be stored and reused. Further, if all the regenerative power is stored in the battery to solve the above problem, the storage capacity of the battery needs to be increased, resulting in an increase in cost.

On the other hand, as a method for effectively utilizing regenerative electric power without increasing the storage capacity, the following various proposals have been made. For example, patent document 1 proposes a technique in which, when the amount of charge in a battery is sufficiently large, regenerative electric power is converted into ac power by an inverter and returned to an external ac power supply, in accordance with a preset condition. Patent document 2 proposes a technique for avoiding continuous generation of regenerative power by setting the weight of a counterweight suspended on the opposite side of a sling with respect to an elevator car to be smaller than the weight of the elevator car when a passenger is zero.

As a method for adjusting the amount of charge of the battery, various methods have been proposed as described below. For example, patent document 3 proposes a technique in which a charge target value for each time zone is set for a charge amount of a battery, the charge target value for an operation peak time zone is set to be smaller than a charge target value for a night time zone in which the operation amount is small, and charging and discharging are performed based on the charge target value. Patent document 4 proposes a technique of estimating a charge amount of a battery at a certain time point after the certain time point, and performing charging when the estimated value is smaller than a predetermined threshold value.

[ patent document 1 ] Japanese patent application laid-open No. 2005-343574

[ patent document 2 ] Japanese patent application laid-open No. 2002-338151

[ patent document 3 ] Japanese patent laid-open No. 2001-187676

[ patent document 4 ] Japanese patent application laid-open No. 2005-86927

However, when the scheme of returning regenerative power to the external ac power supply disclosed in patent document 1 is adopted, it is necessary to use switchable elements (IGBT, GTO, and the like) in an inverter that converts ac power from the external ac power supply into dc power, which leads to an increase in cost. Further, if the regenerative electric power returned to the external ac power supply side can be used for another load of the same customer (for example, power running (power running) for another elevator), no problem arises, and if the regenerative electric power cannot be used for another load of the same customer and the regenerative electric power needs to be used for another customer on the upstream side of the electricity meter, the user is often not approved due to the restriction in the electricity contract. In addition, when the weight of the counter weight disclosed in patent document 2 is set to be smaller than that of the conventional counter weight, a larger power is required in the full load up running operation than in the case of the conventional counter weight, and therefore, a motor having a larger rated power needs to be provided, which leads to an increase in cost.

In patent document 3, the charge target value in the operation peak time zone is set to be small, so that the possibility of securing the free capacity of the battery that charges the regenerative power is increased, but since the charge target value is a value set in advance, and the battery is set to be able to discharge only at the power operation in which the current charge amount of the battery exceeds the charge target value, there is a problem that the battery cannot be discharged at the time of the elevator stop operation. Further, in this proposal, the future charge amount is not specifically predicted, but is discharged based on the current charge amount so as to approach the charge target value as a result, and therefore, when an abrupt state in which the charge target value set in advance is not predicted occurs and the increase in the future charge amount can be predicted, the proposal of patent document 3 does not specifically predict the future charge amount and does not consider actively discharging, and there is a problem that the abrupt state cannot be dealt with.

In the solution of patent document 4, only the case where the energy storage amount is insufficient is considered, and therefore, it is impossible to cope with the case where the energy storage amount is increased due to an increase in the regenerative operation.

Disclosure of Invention

An object of the present invention is to provide an elevator system capable of effectively using regenerative power even when the amount of stored energy is increased due to an abrupt increase in regenerative power without increasing the storage capacity of a power storage device.

Problems other than the above-described problems of the present invention will be described with reference to the drawings or the entire contents of the present specification.

The elevator system of the present invention is characterized in that the future energy storage amount of the energy storage device is estimated, and when the estimated value of the future energy storage amount exceeds a predetermined value, the energy stored in the energy storage device is discharged, and at least a part of the released energy is consumed in the lighting device, the control device, and the like of the elevator car.

The basic idea of the present invention is to estimate in advance whether or not the energy storage amount will become excessive in the future due to continuous generation of regenerative electric power, that is, whether or not the energy storage amount in the energy storage device will exceed the maximum energy storage amount of the energy storage device, and when it is estimated that the energy storage amount will become excessive, to actively perform discharge in advance so as to form a vacant capacity in the energy storage device, so that the regenerative electric power generated thereafter can be charged. In addition, at least a part of the released energy is consumed in the lighting device, the control device and the like of the elevator car, so that the energy storage amount in the energy storage device at the future time point can be actively made as close as possible to the target value of the energy storage amount to be stored by the energy storage device even when the elevator is in a stopped state.

As a discharging method, discharging is performed by controlling a direct-current voltage of a smoothing capacitor of an elevator driving part to be greater than a maximum input voltage inputted from a power supply. After the setting is performed by the above method, the input of power from the power supply is stopped, and the power required for the elevator control power supply device and the lighting device of the elevator car is supplied by discharging the energy storage device. Further, it is preferable that the dc voltage command value of the smoothing capacitor is changed in accordance with a change in the stored excess amount, and when the stored excess amount is large, the set value of the dc voltage command value is increased so that excess energy in the stored energy can be consumed at an early stage.

In the case of supplying power to the elevator car lighting device, the elevator control power supply device for supplying power to the control device, and the like, the arrangement may be such that, at a normal time when the energy storage device is not discharging, the dc voltage of the smoothing capacitor of the elevator driving portion connected to the commercial power supply is converted into the ac voltage to supply power to the elevator control power supply device, the elevator car lighting device, and the like. Further, when the elevator car lighting device, the elevator control power supply device for supplying power to the control device, and the like are connected to other commercial power supplies other than the elevator drive section, a configuration may be adopted in which a power supply source switching device is provided, and when it is estimated that the amount of stored energy will become excessive, the power supply device is switched by the power supply source switching device so that power is supplied by the energy storage device.

As the structure of the present invention, for example, the following structure can be adopted.

(1) An elevator system having: an inverter that rectifies alternating current power from a first commercial power supply to convert it into direct current power; a first inverter connected to a DC side of the converter; an alternating current motor to which alternating current power that is variable-frequency and variable-voltage is supplied by the first inverter; a smoothing capacitor connected between the converter and the first inverter; an energy storage device capable of supplying energy to the alternating-current motor when performing power operation, and capable of storing regenerative electric power when performing regenerative operation; a charging and discharging device that receives and supplies electric power between the smoothing capacitor and the energy storage device; an elevator car driven by the AC motor; and a control device for comprehensively controlling the control of the whole elevator system including the control of the first inverter,

the elevator system further has: a second inverter connected to the smoothing capacitor, converting the direct current into an alternating current, and supplying power to a lighting device and/or the control device of the elevator car;

the control device includes an energy storage amount estimation portion that estimates a future energy storage amount of the energy storage device, and a charge/discharge control portion that determines whether or not an estimated value of the future energy storage amount exceeds a predetermined value, and controls the charge/discharge device to discharge the energy stored in the energy storage device and consume at least a part of the energy released from the energy storage device in the lighting device of the elevator car and/or the control device when it is determined that the estimated value of the future energy storage amount exceeds the predetermined value.

(2) The elevator system according to (1), may be configured such that the charge-discharge control portion controls the charge-discharge device by setting a dc voltage command value at both ends of the smoothing capacitor to be larger than a maximum voltage applied to the inverter from the first commercial power source when discharging the energy stored in the energy storage device.

(3) The elevator system according to (2), may be configured such that the charge-discharge control portion sets, as the direct-current voltage command value, a value obtained by adding the maximum voltage to an amount proportional to an amount of the estimated value of the future energy storage amount that exceeds the target value of the energy storage amount at the future time point.

(4) The elevator system according to any one of (1) to (3), which may be configured to have a power switching device that switches between supplying power to a lighting device and/or the control device of the elevator car by a second commercial power source different from the first commercial power source and supplying power to the lighting device and/or the control device of the elevator car by the second inverter,

the charge-discharge control portion causes the power switching device to switch so as to be supplied with power by the second inverter when discharging the energy stored in the energy storage device.

(5) The elevator system according to any one of (1) to (4), may be configured such that the prescribed value is a value obtained by adding a prescribed threshold value to a target value of the energy storage amount at the future time point.

(6) The elevator system according to (5), may be configured such that the control device has an energy storage device that stores a history of the energy storage amount,

the control device calculates the estimated value and/or the target value of the future energy storage amount from the current energy storage amount and the past energy storage amount.

(7) The elevator system according to (5), may be configured such that the control device has a required electricity usage calculation section that calculates an electricity usage required for the elevator to move to a final destination floor based on load data in the elevator car, data indicating a destination floor registered in the elevator car, and elevator hall call registration data registered in an elevator hall,

the control device calculates the estimated value and/or the target value of the future energy storage amount based on the required used amount calculated in the required used amount calculation section.

The above-described configuration is only an example of various examples, and the present invention may be modified as appropriate within a scope not departing from the technical idea thereof. Further, the configuration examples of the present invention other than the above-described configuration will be described based on the entire contents of the present specification or the drawings.

The main effects of the present invention are as follows.

According to the present invention, by estimating the future energy storage amount, even when the energy storage amount increases due to a sudden increase in regenerative power, the energy stored in the energy storage device is discharged in advance to form a free capacity in the energy storage device before the regenerative power is generated, whereby the generated regenerative power can be effectively used without increasing the storage capacity. Further, by allowing at least a part of the released energy to be consumed by the lighting device, the control device, and the like of the elevator car, the energy storage amount in the energy storage device at the future time point can be actively made as close as possible to the target value of the energy storage amount to be stored by the energy storage device even when the elevator is in a stopped state.

Other effects of the present invention will be described by the entire contents of this specification.

Drawings

Fig. 1 is a structural diagram of an elevator system according to embodiment 1 of the present invention.

Fig. 2 is a specific control block diagram of the dc voltage command setting section in fig. 1.

Fig. 3 is a control flowchart of the dc voltage command setting portion in fig. 1.

Fig. 4 is a detailed control block diagram of the dc voltage control section in fig. 1.

Fig. 5 is a detailed control block diagram of a current control portion of the reservoir apparatus in fig. 1.

Fig. 6 is an explanatory diagram of the energy storage amount adjusting operation of the present invention.

Fig. 7 is a structural diagram of an elevator system according to embodiment 2 of the present invention.

Fig. 8 is a specific control block diagram of the dc voltage command setting section in fig. 7.

Fig. 9 is a control flowchart of the dc voltage command setting portion in fig. 7.

In the figure: 1. 15-alternating current power supply; 2-converter (diode rectifier); 3-a smoothing capacitor; 4. 14-an inverter; 5-an alternating current motor; 6-steel rope pulley of elevator; 7-the suspension ropes of the elevator; 8-the car of the elevator; 9-counterweight of elevator; 10-charge and discharge devices (DC/DC converters and buck-boost choppers); 11-energy storage means (batteries, etc.); 12-a control device; 13-a diode; 16-elevator control power supply means; 17-elevator car lighting; 18-a power switching device; 19-a switch of the power switching device; 20-1, 20-2-terminals of the power switching device; 21-an energy storage sensor; 22-a voltage sensor; 23-a current sensor; 121-a clock; 122-energy storage amount presumption part; 123-energy storage amount deviation calculation section; 124. 124' -a direct current voltage command setting section; 125-direct voltage control part; 126-reservoir current control; 127-a PWM control section; 128-energy storage amount target value calculation section; 129. 129' -a charge-discharge control portion; 1241-threshold judging section; 1242. 1246-change over switch; 1243. 1244, 1245, 1247, 1248-switch terminals; 1251. 1261-an operator; 1252. 1262-proportional-integral compensator.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the drawings and embodiments, the same or similar structural components are denoted by the same reference numerals, and duplicate description is omitted.

[ example 1 ]

Fig. 1 shows a configuration diagram of an elevator system according to embodiment 1 of the present invention. The elevator system of fig. 1 is a "regenerative power storage type elevator system" in which, during regenerative operation, generated regenerative electric power is charged into an energy storage device 11 to store energy, and during power operation, the stored energy is discharged. By reusing the regenerative power, the amount of electricity used from the elevator driving power source can be reduced, and energy can be saved.

First, a basic structure of an elevator driving portion in an elevator system according to the present invention will be described. A three-phase ac power from an ac power supply 1 as a commercial power supply is converted into a dc power by an inverter 2 such as a diode rectifier. The dc power converted by the converter 2 is smoothed by a smoothing capacitor 3, and converted into a three-phase ac power having a variable voltage and a variable frequency by an inverter 4 such as a pwm (pulse Width modulation) inverter. The inverter 4 supplies a variable-voltage and variable-frequency three-phase ac power to the ac motor 5 to perform variable-speed driving. An energy storage device 11, for example, a battery or the like, is connected to both ends of the smoothing capacitor 3 via a charging/discharging device (a DC/DC converter, a step-up/step-down chopper or the like) 10, and the charging/discharging device 10 is controlled by a control device 12. The charging and discharging device (hereinafter, described by taking a DC/DC converter as an example) 10 charges the energy storage device 11 with a direct current according to a control command from the control device 12, or discharges the electric power charged in the energy storage device 11 to the direct current circuit (smoothing capacitor 3) side. The control device 12 has a function of comprehensively controlling the control of the entire elevator system including the control of the inverter 4, in addition to the control of the charging and discharging device 10 described above. In fig. 1, a detailed illustration of a portion for controlling the inverter in the control device 12 and comprehensively controlling the entire system is omitted.

The drive system of the elevator apparatus is composed of a wire rope pulley 6, a suspension rope 7, an elevator car 8, and a counterweight 9, and the elevator car 8 and the counterweight 9 at both ends of the suspension rope 7 can be moved up and down by the ac motor 5.

The following is a supplementary description of each main part of the energy storage system. First, the DC/DC converter constituting the charge/discharge device 10 is composed of an igbt (insulated Gate Bipolar transistor) and a switching element such as a transistor, and is capable of bidirectionally controlling the flow direction of the DC power by a switching action. As the energy storage device 11, a secondary battery such as a lead storage battery, a sealed lead storage battery, a nickel hydride battery, a lithium ion battery, or a NaS battery, a large-capacity capacitor such as an electric double layer capacitor or a lithium ion capacitor, or the like can be used. Control device 12 controls the flow of electric power by providing a control command (gate command) to the switching elements of charge and discharge device 10. As a result, the charging power and the discharging power of the energy storage device 11 can be controlled.

An inverter 14 such as a PWM inverter is connected to the dc circuit (smoothing capacitor 3) of the elevator driving section via a diode 13 for preventing backflow, and the dc voltage is converted into a single-phase ac power having a constant frequency and voltage by the inverter 14. The single-phase alternating current becomes a power supply source of the elevator control power supply device 16, the lighting device 17 of the elevator car, and the like. The elevator control power supply device 16 supplies power to the control device 12, and is used as a control power supply necessary for communication, input reception of button operations, various controls, and the like. The lighting device 17 of the elevator car is a lighting device provided in the elevator car 8.

The processing content of the control device 12 will be described below. The control device 12 has the following two control functions. One of the control functions is a function of controlling the direct-current voltage of the smoothing capacitor 3, and the other control function is a function of controlling the current flowing into the energy storage device 11 or the current flowing out from the energy storage device 11. By combining the two control functions, the following four kinds of control can be realized. The first control is a control of charging the energy storage device 11 from the ac power supply 1, the second control is a control of supplying power from the energy storage device 11 to the elevator control power supply device 16 or the illumination device 17 of the elevator car, the third control is a control of discharging power from the energy storage device 11 and supplying power to the ac motor 5 when the ac motor 5 is in the power running state, and the fourth control is a control of charging the battery 11 with regenerative power when the ac motor 5 is in the regenerative running state. The specific processing of the control device 12 will be described in detail below.

In the control device 12, first, the energy storage amount estimating section 122 estimates the future (after a certain time) energy storage amount estimated value VB' from the current energy storage amount VB of the energy storage device 11 detected by the energy storage amount sensor 21 and the time information t from the clock 121. When the estimation is performed, for example, the power consumption amount of the ac motor 5 is measured, and the estimation is performed based on history data of each time zone, the operation trajectory of the elevator car 8 recorded by a not-shown group management controller, and the like. The future time interval for estimation may be the measurement interval of the power consumption amount or a preset interval such as one hour. As the estimation method, for example, a technique disclosed in patent document 4 (japanese patent laid-open No. 2005-86927) and the like can be used. When the energy storage device 11 is a secondary battery, the energy storage amount sensor 21 actually uses a current sensor, and the integral value of the detection value of the current sensor is used as the current energy storage amount VB, and when the energy storage device 11 is a large-capacity capacitor, the energy storage amount sensor actually uses a voltage sensor, and the current energy storage amount VB is calculated from the voltage value of the voltage sensor.

Then, in the energy storage amount deviation calculating part 123, the energy storage amount target value VB at the future time point calculated by the energy storage amount target value calculating part 128 is calculated based on the future energy storage amount estimated value VB' estimated by the energy storage amount estimating part 122 and the future energy storage amount estimated value VB^*To determine the deviation between them (VB-VB)^*。

Wherein the energy storage amount target value VB calculated by the energy storage amount target value calculating section 128^*Depending on the purpose of use of the energy storage device 11. For example, if the energy storage device 11 is in the "standby operation mode" for driving the elevator even in the event of a power failure, the target value VB of the energy storage amount is set^*The amount of energy stored is the amount of energy required to move the elevator to the nearest floor or the amount of energy stored to perform a predetermined time of operation. If the energy storage device 11 is of a "regenerative power storage system" in which regenerative power is charged during regenerative operation and discharged during power operation, the target value VB of the amount of energy stored therein is^*The value is obtained by subtracting the free capacity required for storing the regenerative electric power generated in the future from the storage limit value of the energy storage device 11. In addition, if the energy storage device 11 is the "peak power reduction method" for reducing the peak power of the input power of the power supply, the amount of energy stored therein is intendedStandard value VB^*The amount of energy required to reduce the peak power (the amount of energy equivalent to the reduced power).

In the process of carrying out the energy storage target value VB^*In the calculation of (b), if it is necessary to predict the future trend, the future energy storage amount is estimated by the same method as the method of calculating the future energy storage amount estimation value VB'. When calculating the future energy storage amount estimation value VB ', the energy storage amount target value VB' is calculated by considering only the current situation and the situation up to the future time point at which the estimation is necessary^*In the calculation of (b), it is also necessary to determine the required energy storage amount target value VB so as not to cause shortage or excess of the energy storage amount at the future time point^*。

For example, the estimated value VB' for determining the future energy storage amount and/or the target value VB for the future energy storage amount at the future time point^*For example, the control device 12 may be configured to provide an energy storage device, not shown, for storing a history of the energy storage amount VB of the energy storage device 11, and calculate the future energy storage amount estimated value VB 'and/or the energy storage amount target value VB' at the future time point based on the current energy storage amount and the future energy storage amount^*。

Further, the estimated value VB' for determining the future energy storage amount and/or the target value VB for the future energy storage amount at the future time point^*The method of (2) may be configured such that the control device 12 has a required electricity usage calculation section, not shown, which calculates the amount of electricity usage required to move to the final destination floor from the load data in the elevator car 8, the data indicating the destination floor registered in the elevator car 8, and the hall call registration data registered in the elevator hall, and such that the control device 12 calculates the future energy storage amount estimation value VB' and/or the energy storage amount target value VB at the future time point from the required electricity usage calculated by the required electricity usage calculation section^*。

Next, dc voltage command setting portion 124 generates dc voltage command Vdc across smoothing capacitor 3 in accordance with future energy storage amount deviation Δ VB^*。

Fig. 2 is a specific control block diagram of the dc voltage command setting section 124 in fig. 1. The deviation Δ VB of the future energy storage amount calculated by the energy storage amount deviation calculation section 123 is compared with the discharge threshold THP and the charge threshold THM in the threshold judgment section 1241. The discharge threshold value THP and the charge threshold value THM are set to be equal to or greater than 0 and the charge threshold value THM is equal to or less than 0 in principle. Wherein the discharge threshold value THP and the charge threshold value THM are based on the target value VB of the energy storage amount^*Degree to be observed, i.e. target value VB of energy storage amount^*The importance of (c) varies. For example, in the energy storage device 11 of the "standby operation mode" or the "peak power reduction mode", the elevator system cannot be operated due to insufficient energy storage amount, and therefore, the charging threshold THM is set to:

THM＝0……(1)

in other cases, the charge/discharge frequency of the energy storage device 11 is set in consideration of the charge/discharge frequency. For example, if the discharge threshold THP and the charge threshold THM are set to values close to 0, the energy storage device 11 frequently changes between the start state and the stop state of charging or discharging, so that the energy storage device is liable to age. Therefore, the discharge threshold THP and the charge threshold THM are set in such a manner as not to cause the energy storage device 11 to frequently change between the start state and the stop state of charging or discharging.

When the threshold value judging section 1241 judges that Δ VB > THP, the estimated energy storage amount VB' in the future exceeds a predetermined value (in this case, the predetermined value is the target energy storage amount VB at the future time point)^*A value obtained by adding the discharge threshold THP), it is determined that discharge is necessary, and the threshold determination part 1241 outputs the determination symbol JSW equal to 0. As a result, the changeover switch 1242 is connected to the switch terminal 1243 side, for exampleDirect-current voltage command value Vdc is shown in formula (4) described later^*The maximum voltage Vsmax of the ac power supply 1 is set to a value obtained by multiplying Δ VB by the scaling factor kd. This is because the larger the deviation Δ VB of the future energy storage amount is, the more the discharge amount needs to be increased to actively bring the deviation Δ VB of the future energy storage amount close to 0. When the ac effective value is 200V, the maximum voltage Vsmax of the ac power supply 1 is 200V

Vsmax＝√2×200＝282.8(V)……(2)

When the AC effective value is 400V, the maximum voltage Vsmax of the AC power supply 1 is

Vsmax＝√2×400＝565.7(V)……(3)

When the threshold value judging section 1241 judges that Δ VB < THM, the estimated energy storage amount VB' at the future time is lower than the predetermined value (in this case, the predetermined value is the target energy storage amount VB at the future time point)^*A value obtained by adding the charging threshold THM), it is determined that charging is necessary, and the threshold determination section 1241 outputs a determination symbol JSW of 2. As a result, change-over switch 1242 is connected to switch terminal 1245 side, and dc voltage command value Vdc is shown in formula (5) described later^*Is set to a value obtained by subtracting Δ VB multiplied by the scaling factor kc from the maximum voltage Vsmax of the ac power supply 1. This is because the larger the absolute value of the deviation Δ VB of the future energy storage amount is, the more the charge amount needs to be increased.

When it is determined in threshold determination section 1241 that charging and discharging are not necessary, output determination symbol JSW is 1. As a result, change-over switch 1242 is connected to switch terminal 1244 side, and dc voltage command value Vdc is shown in formula (6) described later^*Is set to the maximum voltage Vsmax of the ac power supply 1. The above section can be summarized as follows.

Δ VB > THP, Vdc^*＝Vsmax+kd×ΔVB ……(4)

Δ VB < THM, Vdc^*＝Vsmax-kc×ΔVB ……(5)

In cases other than the above two cases, Vdc^*＝Vsmax ……(6)

Fig. 3 shows a control flowchart of the dc voltage command setting section 124 in fig. 1. First, after the control is started (S001), it is determined in the threshold value determining part 1241 (fig. 2) whether or not discharge is required (whether or not Δ VB > THP is satisfied) (S002). When it is determined that discharge is necessary, direct-current voltage command value Vdc is set^*The value shown in expression (4) is set (S003), and the process is ended (S004). When it is determined in S002 that the discharge is not necessary, the threshold determination part 1241 (fig. 2) determines whether or not the charge is necessary (whether or not Δ VB < THM is satisfied) (S005). When it is determined that charging is necessary, DC voltage command value Vdc is set^*The value shown in expression (5) is set (S006), and the process ends (S007). When it is determined in S005 that charging is not necessary, dc voltage command value Vdc is set^*The value shown in equation (6) is set (S008), and the process ends (S009).

The dc voltage command setting section 124 has been explained above. The description is continued with reference to fig. 1.

DC voltage control portion 125 controls DC voltage command value Vdc based on the DC voltage command value Vdc^*And an accumulator current command IB generated from a DC voltage Vdc across the smoothing capacitor 3 detected by a voltage sensor 22^*。

Fig. 4 shows a detailed control block diagram of the dc voltage control section 125 in fig. 1. In dc voltage control portion 125, dc voltage command value Vdc is calculated by calculator 1251^*Deviation from the measured dc voltage Vdc of the smoothing capacitor 3 (Vdc)^*Vdc) and proportional-integral compensation is performed by a proportional-integral compensator (PI compensator) 1252 so that the deviation is zero. The output of the proportional-integral compensator 1252 becomes the storage device current command IB output to the energy storage device 11^*。

The description is continued with reference to fig. 1. The reservoir current control section 126 based on the reservoir current instruction IB^*And an accumulator current IB detected by the current sensor 23, and generating an output voltage command VX to be output to the charging/discharging device 10^*。

Fig. 5 shows a detailed control block diagram of the reservoir device current control section 126 in fig. 1. In the storage device current control portion 126, the storage device current command IB is calculated by the arithmetic unit 1261^*Deviation from measured reservoir current IB (IB)^*IB) and is compensated for by a proportional-integral compensator 1262 so that the deviation is zero. The output of proportional-integral compensator 1262 becomes output voltage command VX to charging/discharging device 10^*。

The description is continued with reference to fig. 1. In the PWM control section 127, the output voltage command VX is output by pulse width modulation^*Converted into a gate signal (gate signal) G for driving the charging/discharging device 10^*. Door signal G^*Is input to the charging/discharging device 10 to perform a desired control (switching control). In this manner, in the control device 12, the dc voltage Vdc and the accumulator current IB can be controlled by the dc voltage control portion 125 and the accumulator current control portion 126, respectively, so that the required charge and discharge control can be performed.

Fig. 6 illustrates an adjustment operation of the energy storage amount when the future energy storage amount estimated value VB' of the energy storage device 11 in the present system is in an excess state. For the sake of explanation, it is assumed that the elevator is in a stopped state. Fig. 6 shows, from top to bottom, a judgment symbol JSW, a dc voltage Vdc, a storage device current IB, a power supply current effective value IS, and an energy storage amount VB. The current time in the figure is t0, and the future energy storage amount estimated value VB' is estimated at this time, and the deviation Δ VB of the future energy storage amount is obtained, and this obtained deviation Δ VB indicates that discharge is necessary.

Thereby, trajectory a1 of determination symbol JSW is changed from 1 to 0, and dc voltage command value Vdc is set^*The locus B1 of (a) is set to a value larger than the maximum voltage Vsmax of the ac power supply 1. By means of a direct voltageControl section 125 (fig. 1) controls trajectory B2 of dc voltage Vdc to follow dc voltage command value Vdc^*. As seen from the locus C2 of the accumulator current IB at this time, the locus C2 rises with the locus C1 of the accumulator current command that rises in order to increase the direct-current voltage Vdc by the accumulator current control portion 126 (fig. 1). In the graph of fig. 6, the discharge is performed when the storage device current IB is greater than 0, and the charge is performed when the storage device current IB is less than 0.

The trajectory D1 of the power supply current effective value IS remains positive before t0 in order to supply power to the elevator control power supply device 16 and the elevator car lighting device 17, but no current flows after the dc voltage Vdc becomes greater than the maximum voltage Vsmax. As described above, the stored energy is discharged from the energy storage device 11, and the energy storage amount VB decreases as indicated by E1. When reaching threshold determination portion 1241 (fig. 2), determines that further discharge is no longer necessary, that is, when t is t1, the discharge is terminated. The energy storage amount VB is adjusted by the above procedure.

According to the present invention, the control device 12 is configured to have an energy storage amount estimating portion 122 for estimating a future energy storage amount of the energy storage device 11, and a charge-discharge control portion 129 that determines whether or not the future energy storage amount estimated value VB' exceeds a prescribed value (for example, the prescribed value is an energy storage amount target value VB at the future time point)^*A value obtained by adding the charging threshold THP), when it is determined that the future energy storage amount estimated value VB' exceeds the predetermined value, the charging/discharging control portion 129 controls the charging/discharging device 10 so that the charging/discharging device 10 discharges the energy stored in the energy storage device 11 and at least a part of the energy released from the energy storage device 11 is consumed by the lighting device 17 and/or the control device 12 of the elevator car 8. Thus, by predicting whether or not the future energy storage amount will become excessive, the energy storage device 11 is discharged in advance to actively form a free capacity in which future regenerative power can be stored in the energy storage device 11, and the elevator is not operated, for example, when the elevator is in a stopped stateEven in the case of forced travel, a large amount of energy can be used for consumption by the elevator control power supply device 16 and the elevator car lighting device 17, and thus the amount of energy stored can be actively reduced for storing regenerative power in the future. In the power running mode, the released energy can be used for the ac motor 5 in addition to the above-described devices.

Further, the present invention is based on the assumption that since the energy consumed by the elevator control power supply device 16 and the elevator car lighting device 17 is not so large, the discharge start control is performed in advance by using the predicted value of the energy storage amount in the future as the target value of the energy storage amount used in the charge and discharge control, instead of using the current value, the energy consumed by the elevator control power supply device 16 and the elevator car lighting device 17 can be increased, and the function of adjusting the energy storage amount can be more effectively exhibited.

Here, for example, as shown in fig. 1, the charge/discharge control section 129 may be configured by the energy storage amount deviation calculation section 123, the dc voltage command setting section 124, the dc voltage control section 125, the storage device current control section 126, the PWM control section 127, and the energy storage amount target value calculation section 128, but the charge/discharge control section 129 is not limited to the above configuration, and may be configured in other configurations as long as it has the same function.

In the present embodiment, as shown in equation (4), the target energy storage amount value VB exceeding the future time point out of the future energy storage amount estimation value VB' is added to the maximum voltage Vsmax^*A value obtained by multiplying (kd × Δ VB) by an amount (deviation Δ VB) proportional to the amount of (d) is set as the dc voltage command value Vdc^*However, the DC voltage command value Vdc^*The maximum voltage Vsmax may be set to a value obtained by adding a predetermined value (for example, a fixed value not proportional to the deviation Δ VB) thereto. Similarly, in the case of charging, a value that is not proportional to the deviation Δ VB may be used instead of kc × Δ VB shown in equation (5).

[ example 2 ]

Fig. 7 shows a configuration diagram of an elevator system according to embodiment 2 of the present invention. The method of supplying power when supplying power to the elevator control power supply device 16, the elevator car lighting device 17, and the like in this embodiment is different from that in embodiment 1. In this embodiment, only the differences from embodiment 1 will be described with reference to fig. 7. The same portions as those in embodiment 1 are denoted by the same reference numerals as those in embodiment 1.

The inverter 14 is connected to a power switching device 18, and constitutes a power supply source for supplying power to an elevator control power supply device 16, an elevator car lighting device 17, and the like, together with an ac power supply 15 (a commercial power supply other than the ac power supply 1) which is a commercial power supply similarly connected to the power switching device 18. Whether the power is supplied from the ac power supply 15 to the elevator control power supply device 16, the elevator car lighting device 17, or the like, or the single-phase ac power converted by the inverter 14 is supplied to the elevator control power supply device 16, the elevator car lighting device 17, or the like, is selected by switching the switch 19 in accordance with the power switch switching command SSW from the control device 12. In a normal case, the switch 19 is set on the terminal 20-2 side so as to be supplied with power from the ac power supply 15.

The processing content of the control device 12 will be described below. The configuration of the dc voltage command setting portion 124' in the control device 12 is different from that of the dc voltage command setting portion 124 in embodiment 1. Thus, in embodiment 2, the charge/discharge control portion 129 of embodiment 1 is changed to the charge/discharge control portion 129'.

In the control device 12, first, the energy storage amount estimation section 122 estimates the future (after a certain time) energy storage amount estimation value VB' from the current energy storage amount VB of the energy storage device 11 detected by the energy storage amount sensor 21 and the time information t from the clock 121. Thereafter, in the energy storage amount deviation calculating section 123, the estimated energy storage amount VB' estimated by the energy storage amount estimating section 122 and the target energy storage amount VB calculated by the target energy storage amount calculating section 128 are used as the basis^*To determine the deviation between them (VB-VB)^*. On the upper partThe above-described treatment was the same as in example 1.

Next, dc voltage command setting portion 124' generates dc voltage command Vdc across smoothing capacitor 3 in accordance with future energy storage amount deviation Δ VB^*And a power switch switching command SSW.

Fig. 8 is a specific control block diagram of the dc voltage command setting section 124' in fig. 7. The deviation Δ VB of the future energy storage amount calculated by the energy storage amount deviation calculation section 123 is compared with the discharge threshold THP and the charge threshold THM in the threshold judgment section 1241. As a result, when Δ VB > THP, a value of 0 is output as the judgment symbol JSW, when Δ VB < THM, a value of 2 is output as the judgment symbol JSW, and when the two cases are other than the above case, a value of 1 is output as the dc voltage command value Vdc, depending on the value of the judgment symbol JSW^*The output values are also different. The above treatment was the same as in example 1.

In embodiment 2, the power switch switching command SSW is switched according to the judgment symbol JSW. When the judgment symbol JSW is 0, that is, when it is judged that the discharge is necessary, the changeover switch 1246 is connected to the switch terminal 1247 side so that the power switch changeover command SSW is 0 in order to connect the elevator control power supply device 16, which is a device consuming the discharged energy, and the elevator car lighting device 17. As a result, in fig. 7, the switch 19 of the power switching device 18 is connected to the terminal 20-1 side, and the power supply sources of the elevator control power supply device 16, the elevator car lighting device 17, and the like become single-phase alternating current power generated by the inverter 14.

On the other hand, when the judgment symbol JSW is 1 or 2, that is, when it is judged that the discharge is not necessary, the changeover switch 1246 is connected to the side of the switch terminal 1248 so that the power switch changeover command SSW is 1 in order to make the power supply sources of the elevator control power supply device 16, the elevator car lighting device 17, and the like the ac power supply 15. As a result, as shown in fig. 7, the switch 19 of the power switching device 18 is connected to the terminal 20-2 side, and the power supply sources of the elevator control power supply device 16, the elevator car lighting device 17, and the like become the ac power supply 15.

Fig. 9 is a control flowchart of the dc voltage command setting portion 124' in fig. 7. After the control is started (S101), it is judged in the threshold judgment part 1241 (fig. 8) whether or not discharge is required (whether or not Δ VB > THP is satisfied) (S102). When it is determined that discharge is necessary, direct-current voltage command value Vdc is set^*The value shown in equation (4) is set (S103), the power switch switching command is set to SSW equal to 0(S104), and the process ends (S105). When it is determined in S102 that the discharge is not necessary, the power switch switching command is set to SSW equal to 1(S106), and the threshold determination section 1241 (fig. 8) determines whether or not the charge is necessary (whether or not Δ VB < THM is satisfied) (S107). When it is determined that charging is necessary, DC voltage command value Vdc is set^*The value shown in expression (5) is set (S108), and the process ends (S109). When it is determined in S107 that charging is not necessary, dc voltage command value Vdc is set^*The value shown in equation (6) is set (S110), and the process ends (S111).

The description is continued with reference to fig. 7. In DC voltage control section 125, according to DC voltage command value Vdc^*And an accumulator current command IB generated from the dc voltage Vdc across the smoothing capacitor 3 detected by the voltage sensor 22^*The current command IB of the accumulator^*Is input into the reservoir current control portion 126. In the storage device current control section 126, in accordance with the storage device current instruction IB^*And an accumulator current IB detected by the current sensor 23, and generating an output voltage command VX to be output to the charging/discharging device 10^*. Further, in the PWM control section 127, the voltage command VX is output by pulse width modulation^*Converted into a gate signal G for driving the charging/discharging device 10^*. Door signal G^*Is input to the charge and discharge device 10 to execute the required control. In this manner, in the control device 12, the dc voltage Vdc and the accumulator current IB can be controlled by the dc voltage control portion 125 and the accumulator current control portion 126, respectively, so that the required charge and discharge control can be performed.

As described above, according to embodiments 1 and 2 of the present invention, it is possible to realize an elevator system in which the regenerative power can be effectively used even when the energy storage amount increases due to an abrupt increase in the regenerative power without increasing the power storage capacity.

The present invention has been described above with reference to the embodiments, and the configurations described in the above embodiments are only examples of various configurations, and the present invention can be modified as appropriate within a range not departing from the technical idea thereof.

Claims (4)

1. An elevator system having: an inverter that rectifies alternating current power from a first commercial power supply to convert it into direct current power; a first inverter connected to a DC side of the converter; an alternating current motor to which alternating current power that is variable-frequency and variable-voltage is supplied by the first inverter; a smoothing capacitor connected between the converter and the first inverter; an energy storage device capable of supplying energy to the alternating-current motor when performing power operation, and capable of storing regenerative electric power when performing regenerative operation; a charging and discharging device that receives and supplies electric power between the smoothing capacitor and the energy storage device; an elevator car driven by the AC motor; and a control device that comprehensively controls control of the entire elevator system including control of the first inverter, the elevator system being characterized in that,

further comprising: a second inverter connected to the smoothing capacitor, converting the direct current into an alternating current, and supplying power to a lighting device and/or the control device of the elevator car;

the control device includes an energy storage amount estimation portion that estimates a future energy storage amount of the energy storage device, and a charge/discharge control portion that determines whether or not an estimated value of the future energy storage amount exceeds a predetermined value, and controls the charge/discharge device to discharge the energy stored in the energy storage device by the charge/discharge device and consume at least a part of the energy released from the energy storage device in the lighting device of the elevator car and/or the control device when it is determined that the estimated value of the future energy storage amount exceeds the predetermined value,

the charge/discharge control section controls the charge/discharge device by setting a dc voltage command value at both ends of the smoothing capacitor to be larger than a maximum voltage applied to the inverter from the first commercial power source when discharging the energy stored in the energy storage device, the charge/discharge control section setting a value obtained by adding an amount proportional to an amount exceeding a target value of the energy storage amount at the future time point among the estimated values of the future energy storage amount to the maximum voltage as the dc voltage command value,

the elevator system has a power supply switching device that switches between supplying power to the lighting device and/or the control device of the elevator car from a second commercial power source different from the first commercial power source and supplying power to the lighting device and/or the control device of the elevator car from the second inverter,

the charge-discharge control portion causes the power switching device to switch so as to be supplied with power by the second inverter when discharging the energy stored in the energy storage device.

2. The elevator system according to claim 1, wherein the prescribed value is a value obtained by adding a prescribed threshold value to the target value of the energy storage amount at the future time point.

3. The elevator system according to claim 2, wherein the control device has an energy storage device that stores a history of the energy storage amount,

the control device calculates the estimated value and/or the target value of the future energy storage amount from the current energy storage amount and the past energy storage amount.

4. The elevator system according to claim 2, wherein the control apparatus has a required electricity usage calculating section that calculates an electricity usage required for the elevator to move to a final destination floor based on load data in the elevator car, data indicating a destination floor registered in the elevator car, and hall call registration data registered in an elevator hall,

the control device calculates the estimated value and/or the target value of the future energy storage amount based on the required used amount calculated in the required used amount calculation section.