WO1999029035A1

WO1999029035A1 - Method for controlling turn-on/off of motor preheater and motor preheater

Info

Publication number: WO1999029035A1
Application number: PCT/JP1998/005315
Authority: WO
Inventors: Yoriyuki Takekawa; Mitsuo Hagiwara
Original assignee: Zexel Corporation
Priority date: 1997-11-28
Filing date: 1998-11-26
Publication date: 1999-06-10
Also published as: JPH11159467A

Abstract

A method for controlling turn-on/off of a motor preheating device, wherein a motor (4) is preheated with a high electric power efficiency by generating heat by hysteresis loss and by resistance loss by periodically reversing the direction of the electric current flowing through the stator coils (6a, 6b, and 6c) of the motor (4). The method comprises turning on/off a first transistor (10) in a prescribed cycle for a prescribed time T1, keeping on fifth and sixth transistors (14, 15) during the prescribed time T1, stopping the driving of the transistors (14, 15) for a prescribed time T2, thereafter, for a prescribed time T3, turning on/off a fourth transistor (13) in a prescribed cycle and keeping on second and third transistors (11, 12) then, stopping the driving of the transistors (11, 12) for a prescribed time T4, and repeating the steps.

Description

Description Electricity control method in motor preheating device and motor preheating device

The present invention relates to, for example, a preheating device for an electric motor used for driving a compressor of an air conditioner, and more particularly to a device for improving the preheating efficiency. Background art

Conventionally, in an air conditioner, the compressor is heated in advance from the viewpoint of preventing the compressor cooled by the ambient temperature from being damaged by the liquid refrigerant generated by cooling at the start-up during heating. In particular, in the case of a motor that has a motor integrated with a compressor, it has become known and well-known that power is supplied to the excitation coil of the motor to apply preheating. (For example, refer to Japanese Patent Publication No. 6-70541, Japanese Patent Publication No. 5-41838).

However, those disclosed in any of the publications use only the heat generated by the so-called resistance loss, and it cannot be said that the heat generation efficiency with respect to the current consumption is always good.

As a method of energizing the coil, there is a method in which intermittent energization is performed (see Japanese Patent Publication No. 5-41838). However, it is necessary to minimize the loss caused by the intermittent control of the switching element. However, there is a problem that the loss due to the switching element cannot be ignored.

An object of the present invention is to provide an energization control method and a motor preheating device in a motor preheating device that can perform sufficient preheating with a minimum current consumption and that have high power efficiency. Is to do.

Another object of the present invention is to provide an energization control method and a motor preheating device in a motor preheating device capable of performing preheating with high power efficiency while minimizing the loss of a switching element.

Still another object of the present invention is to provide a method for controlling power supply in a motor preheating device and a motor preheating device that can reduce the burden of so-called heat radiation design. Disclosure of the invention

According to the present invention, a switching element is bridge-connected between a power supply and a ground, and a power supply control is performed in a motor preheating device configured to supply power to a stationary coil of a motor for driving a compressor. A switching element having one end connected to the power supply side, and one of the switching elements having one end connected to the ground side at the same time as turning on and off at a predetermined repetition cycle for a predetermined time. The two switches are turned on for the predetermined time, and thereafter, the corresponding switching elements are repeatedly controlled in the same manner as described above so that the current flowing through the coils is reversed. A control method is provided.

In such a method, in particular, by changing the switching element that is turned on and off periodically, the current direction of the coil is periodically reversed, and the conventional so-called resistance loss The power efficiency is improved by generating not only heat due to heat but also heat due to hysteresis loss.

Further, according to the second aspect of the present invention, the switching element is bridge-connected between the power supply and the ground, so that power is supplied to the motor coil for driving the compressor. Control in a preheated motor preheating device The method

One of a plurality of switching elements connected in series between the power supply and the ground is turned on and off at a predetermined repetition cycle, and the other switching element is turned on during this period. An energization control method configured as described above is provided.

In particular, such a method replaces the conventional operation control in which one switching element is repeatedly turned on and off for a predetermined time, and after a certain time, is again turned off and off for the same predetermined time, instead of a conventional operation control. After turning off the drive for a certain period of time and then turning it on again for a certain period of time, the number of switching operations per unit time is reduced, and so-called switching loss is reduced while high efficiency is achieved. Preheating can be performed.

Further, according to the third aspect of the present invention, a switching element is connected by a plug between the power supply and the ground, and energizing means for energizing a stator coil of a motor driving the compressor,

A motor preheating device comprising: a control unit that controls operation of the energizing unit.

The control means turns on and off one of the switching elements, one end of which is connected to the power supply side, at a predetermined repetition cycle for a predetermined time, and at the same time, one of the switching elements, one end of which is connected to the ground side. An electric motor configured to repeatedly turn on the corresponding switching elements in the same manner as described above so that the two are turned on for the predetermined time, and thereafter the current flowing through the coil is in the opposite direction. A preheating device is provided.

Such a configuration is suitable for executing the energization control method according to the first aspect of the present invention. In particular, the control means can be realized by, for example, executing a so-called software by a microcomputer. , This The switching element that is turned on and off is periodically changed by the control of the energizing means by such a control means as described above, and the current direction of the stay coil is periodically changed to the opposite direction. In addition to heat generation, power efficiency is improved by generating heat due to hysteresis loss.

Further, according to the fourth aspect of the present invention, the switching element is connected by a bridge between the power supply and the ground, and energizing means for energizing the stay coil of the motor driving the compressor,

The control means simultaneously turns on any two of the switching elements having one end connected to the ground side for a predetermined time, and switches any one of the switching elements having one end connected to the power supply side. The on state is maintained for a predetermined time shorter than the predetermined time, and thereafter, the control of the corresponding switching element in the same manner as described above is repeated so that the current flowing through the stay coil is in the opposite direction. An electric motor preheating device is provided.

In such a configuration, in particular, the control means can be realized by, for example, execution of so-called software by a microcomputer.

By controlling the energizing means by such control means, the combination of the switching elements is periodically changed so that the direction of the current of the stay coil is periodically reversed, and furthermore, the on / off of the switching elements is performed. As a result, the power efficiency is improved by not only generating heat due to the so-called resistance loss, but also generating heat due to hysteresis loss, and the switching loss of the switching element is reduced. . Still further, according to the fifth aspect of the invention, a compressor input from the outside Preheating determination means for determining whether or not preheating is necessary based on a signal regarding the atmosphere of

Heating amount determining means for setting an energizing period based on a signal about the atmosphere of the compressor inputted from outside;

A drive element for bridge-connecting a switching element between a power supply and a ground to energize a coil of a motor for driving the compressor, and outputs of the preheating determination means and the heating amount determination means; A preheating signal generating means for controlling the operation of the driving means based on the signal;

The preheating signal generating means is configured such that one of a plurality of switching elements connected in series between the power supply and the ground is turned on and off at a predetermined repetition cycle, and during the other, An electric motor preheating device configured to control the operation of the driving means so that the switching element is turned on.

Such a configuration is suitable for executing the energization control method according to the second aspect of the present invention. In particular, the preheating determination unit, the heating amount determination unit, and the preheating signal generation unit include, for example, a so-called software using a microcomputer. This can be achieved by executing a to-air. With this configuration, similarly to the energization control method according to the second aspect of the present invention, the number of times of switching of the switching element is reduced, and so-called switching loss is reduced, and preheating with high power efficiency can be performed.

Further, according to the sixth aspect of the invention, the preheating determination means for determining whether or not the preheating is necessary based on a signal regarding the atmosphere of the compressor input from the outside, and the atmosphere of the compressor input from the outside. Heating amount determining means for setting an energizing period based on a signal related to

A drive unit that bridges a switching element between the power supply and the ground to energize a stationary coil of a motor that drives the compressor; A preheating signal generating unit that controls the operation of the driving unit based on each output signal of the preheating determining unit and the heating amount determining unit,

The preheating signal generating means may be configured such that one of a plurality of switching elements connected in series between the power supply and the ground is turned on / off at a predetermined repetition cycle, and An electric motor preheating device configured to control the operation of the driving means so that the switching element of the above is turned on.

Further, an overcurrent detecting means for detecting that the current of the motor driving the compressor has reached the overcurrent value is provided.

The preheating signal generating means is configured so that the time until the overcurrent detection means detects that the current of the current reaches the overcurrent value is set as the on time of the switching element that is turned on and off. An electric motor preheating device is provided.

In such a configuration, the on-time of the switching element that is turned on and off is set within a range where the current of the motor does not become an overcurrent, so that preheating can be performed efficiently without consuming excessive power. You can do it. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a configuration diagram illustrating a first configuration example of a motor preheating device according to an embodiment of the present invention.

FIG. 2 is a main flowchart illustrating a control operation of the motor preheating device according to the embodiment of the present invention.

FIG. 3 is a subroutine flowchart illustrating a more specific control procedure of the preheating energization process shown in FIG.

FIG. 4 is a timing chart showing the timing of the main part in the energization control for preheating in the first configuration example, and FIG. 4 (A) shows the first transformer. 4 (B) is a timing chart showing the operation state of the second transistor, FIG. 4 (C) is a timing chart showing the operation state of the third transistor, and FIG. D) is a timing chart showing the operating state of the fourth transistor, FIG. 4 (E) is a timing chart showing the operating state of the fifth transistor, and FIG. 4 (F) is a timing chart showing the operating state of the sixth transistor FIG.

FIG. 5 is an explanatory diagram illustrating the directions of currents flowing through the first to third stay coils when current is supplied at the timing shown in FIG.

FIG. 6 is a timing chart showing the timing of the main part in the energization control for preheating in the second configuration example, and FIG. 6 (A) is a timing chart showing the operation state of the first transistor. FIG. 6 (B) is a timing chart showing the operation state of the second transistor, FIG. 6 (C) is a timing chart showing the operation state of the third transistor, and FIG. 6 (D) is an operation state of the fourth transistor. FIG. 6E is a timing chart showing the operation state of the fifth transistor, FIG. 6F is a timing chart showing the operation state of the sixth transistor, and FIG. FIG. 6 is a timing chart showing the state of the power supply current of FIG.

FIG. 7 is a configuration diagram showing a configuration of a motor preheating device in a third configuration example.

FIG. 8 is a timing chart showing the timing of the main part in the energization control for preheating in the third configuration example, and FIG. 8 (A) is a timing chart showing the operation state of the first transistor. 8 (B) is a timing chart showing the operating state of the second transistor, FIG. 8 (C) is a timing chart showing the operating state of the third transistor, and FIG. 8 (D) is an operating state of the fourth transistor. FIG. 8E is a timing chart showing the operation state of the fifth transistor, and FIG. 8F is a timing chart showing the operation state of the sixth transistor. Figure 8 (G) is a timing diagram showing the state of the power supply current in the motor.

FIG. 9 is a configuration diagram functionally showing a configuration example of a motor preheating device in a fourth configuration example.

FIG. 10 is a timing chart showing the timing of the main part in the energization control for preheating in the fourth configuration example, and FIG. 10 (A) is a timing chart showing the operation state of the first transistor. FIG. 10 (B) is a timing chart showing the operation state of the fifth transistor, and FIG. 10 (C) is a timing chart showing the operation states of the second to fourth transistors and the sixth transistor. 10 (D) is a timing chart showing the state of the power supply current over time. FIG. 11 is a configuration diagram functionally showing a configuration example of a motor preheating device in a fifth configuration example.

FIG. 12 is a timing chart showing the timing of the main part in the energization control for preheating in the fifth configuration example, and FIG. 12 (A) is a timing chart showing the operation state of the first transistor. FIG. 12 (B) is a timing chart showing the operation state of the fifth transistor, FIG. 12 (C) is a timing chart showing the operation state of the second to fourth transistors and the sixth transistor, FIG. 12D is a timing chart showing the state of the power supply current of the motor. BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in more detail with reference to the accompanying drawings.

The members, arrangement, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

First, the configuration of the motor preheating device in the first configuration example will be described with reference to FIG. PT 5

This electric motor preheating device is roughly divided into an energization drive unit 1, a drive control unit (denoted as “DRC” in FIG. 1) 2, and a microcomputer 3. This is for controlling the operation of an electric motor provided integrally with a compressor used for a vehicle air conditioner (not shown). As the electric motor, for example, a brushless motor 4 is used.

First, the brushless motor 4 will be described. The brushless motor 4 is composed of a low-speed motor 5 using permanent magnets, three stages of U, V, and W phase coils 6a to 6c, and It is a well-known and well-known device having three hall elements 7 a to 7 c appropriately arranged around evening 5 as main components.

The first to third stay coils 6 a to 6 c are so-called Y-connected and connected to an energization driving unit 1, which will be described later, and the energization driving unit 1 performs known and known energization control. It is like that.

The energization drive unit 1 has six switching elements connected in a so-called three-phase bridge connection to the first to third stay coils 6 a to 6 c, and receives a control signal from the drive control unit 2. Accordingly, each switching element is so-called turned on / off, whereby the DC power from the DC power supply 8 is converted into AC power, and the first to third stay coils 6a to 6c are turned on. A so-called circuit for overnight circuit supplied to 6 c is configured. That is, the energization drive unit 1 has six npn-type first to sixth transistors 10 to 15 as switching elements as main components, and these first to sixth transistors 10 to 15 are so-called switching elements. It is a three-phase bridge connected.

Specifically, the collectors of the first to third transistors 10 to 12 are connected to the positive side of the DC power supply 8 and the respective collectors of the fourth to sixth transistors 13 to 15. The first transistor 10 and the fourth transistor 13 are connected to the second transistor 11 and the fifth transistor 14 and the third power so that the current is on the negative side of the DC power supply 8. The transistor 12 and the sixth transistor 15 are connected in series.

One end of the first stage coil 6a is connected to the mutual connection point of the first and fourth transistors 10 and 13, and the second and fifth transistors 11 and 14 are connected to each other. One end of the second stationary coil 6b is connected to the mutual connecting point, and the third stationary coil 6c is connected to the connecting point of the third and sixth transistors 12 and 15. Are connected to each other.

Further, so-called reflux diodes 16a to 16f are connected to the first to sixth transistors 10 to 15 in parallel between the collector and the emitter, respectively.

Each of the bases of the first to sixth transistors 10 to 15 is connected to the output stage of the energization driving unit 1, and a pulse for driving the first to sixth transistors 10 to 15 is provided. The signal is applied by the energization driver 1.

Note that in FIGS. 1, 4, 6, 6, 7, 10, and 12, "U +" denotes the first transistor 10, and "V +" denotes the second transistor 11. “W +” represents the third transistor 12, “U j represents the fourth transistor 13,“ V− ”represents the fifth transistor 14, and“ W represents the sixth transistor 12. Evening 15 shall be represented respectively.

The drive control unit 2 generates and outputs a pulse signal to the first to sixth transistors 10 to 15 of the energization drive unit 1 according to a control signal from the microcomputer 3. Things.

The microcomputer 3 is a well-known IC-known device. Any environment signal (details will be described later) and the output signals of the first to third Hall elements 7a to 7c are input, and as will be described later, power is supplied through the drive control unit 2 based on these input signals. The operation of the drive unit 1 is controlled.

Here, the environmental signal is a signal that can determine various weather conditions in which a compressor (not shown) is placed. Specifically, for example, the outside air temperature, the vehicle interior temperature, the compressor temperature, etc. It is preferable to use. These sensors use the output signals of the sensors for acquiring data, which are already provided in a vehicle air conditioner (not shown), so that there is no need to provide a new sensor and input. Things.

Next, the operation of the motor preheating device will be described with reference to FIGS.

First, when the control operation by the microcomputer 3 is started, an environmental signal is detected, that is, the environmental signal such as the outside air temperature and the vehicle interior temperature is read into the microcomputer 3 as described above. (See step 100 in Figure 2).

Then, it is determined whether or not it is time to start preheating based on a predetermined criterion using the environmental signal (see step 110 in FIG. 2), and if it is determined that it is the time to start preheating (YES) In this case, the preheating energization process, which will be described in detail later, is performed (see step 120 in FIG. 2).

Subsequently, an environmental signal is detected again in the same manner as in the previous step 100 (see step 140 in FIG. 2), and it is determined based on the environmental signal whether the preheating end time has come. Then, (see step 150 in FIG. 2), if it is determined that the preheating end time is reached (in the case of YES), the preheating energizing process is ended. On the other hand, if it is determined that it is not time to end preheating (in the case of N〇), the process returns to step 120 and the preheating energization process is repeated and continued. Here, the preheating energizing process will be described more specifically with reference to FIGS. 3 to 5.First, the microcomputer 3 drives the U-phase so that current flows from the U-phase to each of the V and W phases. The control of the energizing drive unit 1 is performed via the control unit 2 (see steps 122 in FIG. 3).

That is, during the first predetermined time T1, the fifth and sixth transistors 14 and 15 are turned on, and the first transistor 10 is turned on during the first predetermined time T1. It is turned on and off at a predetermined repetition cycle (see FIGS. 4 (A), 4 (E) and 4 (F)). As a result, as shown by the solid arrow in FIG. 5, the first stage coil 6a, which is the U phase, the second stator coil 6b, which is the V phase, and the third stage coil which is the W phase. Current will flow to the coil 6 overnight. Therefore, _c and so that the heat generation occurs due to the resistance loss of the first to third stearyl Isseki coil 6 a to 6 c by the energization, after a first predetermined time T 1 energized as described above The power supply is suspended for the second predetermined time T2 (see steps 124 and FIG. 4A to FIG. 4F in FIG. 3).

Thereafter, energization is started again. In this case, the energization drive unit 1 is driven by the microcomputer 3 via the drive control unit 2 so that current flows from the V and W phases to the U phase. It will be controlled (see steps 126 in FIG. 3).

That is, during the third predetermined time T3, the second and third transistors 11 and 12 are turned on, and the fourth transistor 13 is turned on during the third predetermined time T3. It is turned on and off at a predetermined repetition cycle (see FIGS. 4 (B) to 4 (D)).

As a result, as shown by the dotted arrows in FIG. 5, the V and W phases of the second and third stay coils 6b and 6c are converted to the V phase of the first stay coil 6a. The current is circulated toward this. Therefore, this As a result, heat is generated due to the resistance loss of the first to third stay coils 6a to 6c.

Here, the direction of the synthetic magnetic field generated when energizing in step 122 and the direction of the synthetic magnetic field generated when energizing in step 126 are the same as those in the first to third coils. Depending on the direction of the current for 6a to 6c (see Fig. 5), the direction is just the opposite.

Therefore, the steel plate (not shown) on which the coils 6a to 6c are wound is not rotated by the power supply for the preheating, and the steel plates (not shown) on which the coils 6a to 6c are wound. As a result, the electrodes are exposed to magnetic fields in opposite directions, so that a so-called hysteresis loss is generated, which also generates heat.

After the energization for the third predetermined time T3 as described above, the first to third stay coils 6a to 6c by the energization driving unit 1 for the fourth predetermined time T4. The power supply to the power supply is stopped (see FIGS. 4 (A) to 4 (F)), and then, at one end, the routine returns to the main routine described above (see FIG. 2), and preheating is still required as described above. If it is determined that there is (“NO” in step 150 of FIG. 2), the processing after step 122 described above is repeated again.

Here, the suspension of energization during the second predetermined time T2 and the fourth predetermined time T4 is a protection of the switching element against a so-called circulating current, that is, the first to sixth transistors 10 to 15 It is provided for protection.

Also, the first predetermined time T1> the third predetermined time T3 is set so that even if the position of the mouth 5 is slightly shifted due to a disturbance or the like, it does not rotate during the second predetermined time T2. That's why.

In the first configuration example described above, the energization drive unit 1 and the drive control unit 2 Further, the energizing means according to claim 3 is realized by the microcomputer 3 and the control means according to claim 3 is realized respectively.

Next, a second configuration example will be described with reference to FIGS. 1 to 3 and FIG.

In the second configuration example, the configuration as so-called hardware may be the configuration shown in FIG. 1 and the operation control by the microcomputer 3 is changed.

The basic control procedure is the same as that shown in FIGS. 2 and 3, but the specific energization timing and the like are different as described below. Therefore, in the following description, the description will be made with reference to FIGS. 2 and 3 as appropriate.

That is, in step 122, the first transistor 10 is turned on for the first predetermined time T1 (see FIG. 6A), while the fifth and sixth transistors 14 and 14 are turned on. 15 is also made conductive (see FIGS. 6 (E) and 6 (F)). Accordingly, this energization generates heat due to the resistance loss of the first to third stay coils 6a to 6c.

Here, the first predetermined time T1 is one in which the power supply current of the brushless motor 4 is set to reach the rated current I _R (see FIGS. 6 (A) and 6 (G)).

After the elapse of the first predetermined time T1, the first transistor 10 is turned off and the power supply is stopped for the second predetermined time T2 (steps 124 and FIG. 6 in FIG. 3). (A)). On the other hand, during the second predetermined time T2, the fifth and sixth transistors 14 and 15 are kept conductive (see FIGS. 6 (E) and 6 (F)).

Here, the second predetermined time T2 is determined by the required amount of heating, and is determined by using a micro-computer using a predetermined arithmetic expression based on the environmental signal. Calculated by Compute 3

Then, the energization is started again. In this case, the energization drive unit 1 is controlled by the microcomputer 3 via the drive control unit 2 so that the current flows from the V and W phases to the U phase. (See steps 1 and 26 in Figure 3).

That is, during the third predetermined time T3, the fourth transistor 13 is turned on (see FIG. 6D), and the second and third transistors 11 and 12 are also turned on. (See Fig. 6 (B) and Fig. 6 (C)). Accordingly, this energization generates heat due to the resistance loss of the first to third coils 6a to 6c.

Here, the third predetermined time T 3 is set so that the power supply current of the brushless motor 4 reaches the rated current (1 I) by the conduction of the fourth transistor 13 (FIG. 6). (D) and Fig. 6 (G)).

In addition, the direction of the synthetic magnetic field generated when energizing in step 122 and the direction of the synthetic magnetic field generated in energizing in step 126 are as described above in the first to third steps. The reverse direction is just like the first configuration example, depending on the direction of the current to the coils 6a to 6c.

Therefore, the mouth 5 is not rotated by the current for preheating, and the steel plate (not shown) on which the coils 6a to 6c are wound is connected to the steps 122, 122. The energization by 6 results in exposure to magnetic fields in opposite directions, so that a so-called hysteresis loss is generated, which also generates heat, similarly to the first configuration example.

Then, after the lapse of the third predetermined time T3, the fourth transistor 13 is turned off and the power supply is stopped during the fourth predetermined time T4 (see FIG. 6 (D)). The second and third transistors 11 and 12 are kept conductive during this time (see FIGS. 6B and 6C). So Then, once returning to the main routine (see FIG. 2), as described above, when it is determined that preheating is still necessary (in the case of “NO” in step 150 of FIG. 2), The processing after step 122 is repeated again.

Here, the fourth predetermined time T4 is determined based on the required heating amount, similarly to the second predetermined time T2, and is calculated in advance based on the environmental signal. This is calculated by the microcomputer 3 using the formula.

In the case of the second configuration example, unlike the above-described first configuration example, the first to sixth transistors 10 are used at the first predetermined time T1 and the second predetermined time T2, respectively. Since any one of (1) to (15) is not turned on and off a plurality of times, the number of switching operations per unit time is small, and so-called switching loss is reduced.

In the second configuration example described above, the energizing means according to claim 4 is realized by the energizing drive unit 1 and the drive control unit 2, and the control means according to claim 4 is realized by the microcomputer 3. It has become.

Next, a third configuration example will be described with reference to FIGS. In the third configuration example, first, generally speaking, in the second configuration example described above, the conduction period of the first transistor 10 is substantially equal to the power supply current of the brushless memory 4. The difference is that the power supply current of the brushless motor 4 is set to substantially reach the overcurrent value while the current is set to reach the current, and the other components are basically the same.

More specifically, as shown in FIG. 7, the motor preheating device in the third configuration example includes a negative electrode of a DC power supply 8 and fourth to sixth transistors 13 to The resistor 17 for overcurrent detection is connected in series between the emitters of 15 and the fourth to sixth transistors of the resistor 17 for overcurrent detection. The connection point between each of the switches 13 to 15 is connected to the input port of the microcomputer 1 and the voltage drop at the overcurrent detection resistor 17 The configuration is such that the overcurrent of the brushless mode 4 is determined by the 3rd mode. The other components are the same as those shown in FIG. 1, and therefore, the same components will be denoted by the same reference characters, and detailed description thereof will be omitted below. Next, the operation in such a configuration will be described with reference to FIGS. 8 (A) to 8 (G).

First, the basic control procedure is the same as that shown in FIGS. 2 and 3, but the actual energization timing and the like are different as described below. Therefore, in the following description, description will be made while appropriately diverting FIGS. 2 and 3.

That is, in step 122, the first transistor 10 is turned on for the first predetermined time T1 (see FIG. 8A), while the fifth and sixth transistors 14 and 14 are turned on. Similarly, 15 is made conductive (see FIGS. 8 (E) and 8 (F)). Therefore, this energization generates heat due to the resistance loss of the first to third stay coils 6a to 6c.

Here, the first predetermined time T1 is determined when the microcomputer 3 determines that the voltage of the overcurrent detection resistor 17 has exceeded the predetermined value and is an overcurrent (see FIGS. 8A and 8B). G)), which is determined by turning off the first transistor 10.

After the lapse of the first predetermined time T1, the first transistor 10 is turned off and the power supply is stopped for the second predetermined time T2 (steps 124 and FIG. 8 in FIG. 3). (See (A)). On the other hand, during the second predetermined time T2, the fifth and sixth transistors 14 and 15 are kept conductive (see FIGS. 8E and 8F). Here, the second predetermined time T 2 is determined by the required amount of heating, and is calculated by the microcomputer 3 using a predetermined arithmetic expression based on the environmental signal. is there.

Then, energization is started again. In this case, the energization drive unit 1 is controlled by the microcomputer 3 via the drive control unit 2 so that current flows from each phase of V and W to the U phase. (See steps 1 and 2 in Figure 3).

That is, during the third predetermined time # 3, the fourth transistor 13 is turned on (see FIG. 8D), and the second and third transistors 11 and 12 are also turned on. (See Figure 8 (Β) and Figure 8 (C)). Accordingly, this energization generates heat due to the resistance loss of the first to third coils 6a to 6c.

Here, the third predetermined time T3 is determined when the microcomputer 3 determines that the voltage of the overcurrent detection resistor 17 has exceeded the predetermined value and is an overcurrent (see FIGS. 8D and 8 G)), but it is determined by turning off the fourth transistor 13.

Also, the direction of the composite magnetic field generated when energizing in step 122 and the direction of the composite magnetic field generated in energizing in step 126 are the same as those in the first to third coils described above. The reverse direction is just the same as in the first configuration example, depending on the direction of the current with respect to 6a to 6c.

Therefore, the steel plate (not shown) on which the coils 6a to 6c are wound is not rotated by the power supply for the preheating, and the steel plates (not shown) on which the coils 6a to 6c are wound. As a result of being exposed to magnetic fields in directions opposite to each other due to energization by, a so-called hysteresis loss is generated and heat is also generated by this, as in the first configuration example.

After the lapse of the third predetermined time T3, during the fourth predetermined time T4, The fourth transistor 13 is turned off and the power is turned off (see FIG. 6 (D)). Meanwhile, the second and third transistors 11 and 12 are continuously turned on during this time. (See Fig. 8 (B) and Fig. 8 (C)). Then, once returning to the main routine (see FIG. 2), as described above, if it is determined that preheating is still necessary (in the case of “NO” in step 150 of FIG. 2), The processing after step 122 described above will be repeated again.

Here, the fourth predetermined time T4 is determined based on the required heating amount, similarly to the second predetermined time T2, and is calculated in advance based on the environmental signal. It is calculated by microcomputer 3 using the formula.

In the case of the third configuration example, unlike the above-described first configuration example, the first to sixth transistors 10 are used in each of the first predetermined time T1 and the second predetermined time T2. Since any one of (1) to (15) is not turned on and off a plurality of times, the number of switching operations per unit time is small, and so-called switching loss is reduced.

Next, a fourth configuration example will be described with reference to FIGS. First, a configuration of the motor preheating device in the fourth configuration example, particularly a configuration focusing on the functional aspect, will be described with reference to FIG.

That is, the motor preheating device in the fourth configuration example includes a preheating determination means 20, a heating amount determining means 21, a preheating signal generating means 22, and a driving means 23, It is designed to preheat an integrated compressor.

The preheating determination means 20 is for inputting the environmental signal as described in the first configuration example, and for determining the necessity of preheating based on the input.

The heating amount determination means 21 also receives an environmental signal, and The amount of heating (heat generation) is calculated, and the energization time and energization stop time are calculated according to the amount of heating.

The preheating signal generating means 22 is a control signal for energizing the electric motor of the motor-integrated compressor through the driving means 23 based on the signals from the preheating determining means 20 and the heating amount determining means 21. Is to occur.

The driving means 23 is for actually energizing the electric motor based on the control signal from the preheating signal generating means 22.

A more specific configuration having such functional units is preferably, for example, a configuration as shown in FIG. 1 as shown above.

That is, in this case, the preheating determining means 20, the heating amount determining means 21 and the preheating signal generating means 22 are realized by the microcomputer 3, and the driving means 23 is composed of the energizing driving section 1 and the driving control section. This is realized by 2.

Next, energization control in the fourth configuration example will be described with reference to FIGS.

In the fourth configuration example, the microcomputer 3 determines the necessity of preheating based on the environmental signal in the same manner as in the first and second configuration examples, and determines that preheating is necessary. Then, the energization as described below is started.

That is, when it is determined that the preheating is started, the first transistor 10 is turned on for a predetermined conduction time T ON (see FIG. 10 (A)), and thereafter, for a predetermined non-conduction time T. ! During ^, the non-conducting state is repeated (see Figure 10 (A)).

In addition, during the repetition of the conduction and non-conduction of the first transistor 10, the fifth transistor 14 is continuously turned on (see FIG. 10B). Then, the second to fourth transistors 11 to 13 and the The transistor 15 of No. 6 is turned off during this energization control (see FIG. 10 (C)).

Accordingly, while the first transistor 10 is in the conductive state, current flows through the first stay coil 6a and the second stay coil 6b, and heat is generated due to resistance loss. Become.

Here, the predetermined conduction time TON is set to such a time that the currents of the first and second stay coils 6a and 6b can substantially reach the rated current (FIG. 10). (D)).

Also, the predetermined non-conducting time T. _Fr is a time determined based on the amount of heating required for a compressor (not shown), and is set to a shorter time as the amount of heating increases. Note that this non-conduction time T. _{The FF} may be changed according to a predetermined reference based on environmental signals such as the outside air temperature and the compressor temperature.

Then, the above-described energization control is stopped when it is determined that preheating is unnecessary based on the environmental signal or when the operation of the compressor is started, and the normal operation state, that is, the opening 5 It will be in a rotating state.

In the above-described control example, the first transistor 10 is turned on and off, and the fifth transistor 14 is turned on continuously during that time. However, another combination of transistors may be used. Needless to say, for example, the first transistor 10 may be turned on and off, and the sixth transistor 15 may be continuously turned on during that time, and the second transistor 11 may be turned on and off. At the same time, the fourth transistor 13 may be turned on.

Further, as described above, in addition to allowing a current to flow only through a certain combination of transistors, in other words, a certain combination of phases, the combination of phases to be energized may be sequentially changed at predetermined time intervals. In that case, -11--As described above, preheating unevenness will be reduced as compared with the case where a specific phase is continuously energized.

Next, a fifth configuration example will be described with reference to FIGS. First, the configuration of the motor preheating device in the fifth configuration example, particularly the configuration focusing on the functional aspect, will be described with reference to FIG.

That is, the motor preheating device in the fifth configuration example includes a preheating determination means 20, a heating amount determining means 21, an overcurrent detecting means 24, a preheating signal generating means 22, and a driving means 2. 3 to preheat the motor-integrated compressor. In the motor preheating device according to the fifth configuration example, the other units except the overcurrent detection unit 24 have the same functions as those in the fourth configuration example shown in FIG. The components are denoted by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, different points will be mainly described.

The overcurrent detecting means 24 is for detecting the power supply current of the electric motor, that is, the brushless motor 4, and judging that the microcomputer 3 is overcurrent.

A more specific configuration having such functional units is preferably a configuration as shown in FIG. 7, for example, as already shown.

That is, in this case, the preheating determining means 20, the heating amount determining means 21 and the preheating signal generating means 22 are realized by the microcomputer 3, and the overcurrent detecting means 24 is provided with the overcurrent detecting resistor 1. According to 7, the driving means 23 is realized by the energization driving unit 1 and the driving control unit 2, respectively. Next, energization control in the fifth configuration example will be described with reference to FIGS. 1 and 12. FIG.

In the fifth configuration example, the microcomputer 3 determines whether or not the preheating is necessary based on the environmental signal according to the first and second configuration examples. Similarly, if it is determined that it is necessary, the energization will be started as described below.

That is, when it is determined that the preheating is started, the first transistor 10 is turned on for a predetermined conduction time T o (see FIG. 12 (A)), and thereafter, for a predetermined non-conduction time. T. During this time, the non-conductive state is repeated (see Fig. 12 (A)).

In addition, during the repetition of conduction and non-conduction of the first transistor 10, the fifth transistor 14 is continuously turned on (see FIG. 12B). Then, the second to fourth transistors 11 to 13 and the sixth transistor 15 are turned off during the energization control (see FIG. 12C).

Therefore, while the first transistor 10 is in the conductive state, current flows through the first stay coil 6a and the second stay coil 6 and heat is generated due to resistance loss. .

Here, the predetermined conduction time TON is a time until it is determined that the power supply current of the brushless motor 4 has substantially reached the overcurrent value (see FIG. 12 (D)). The microcomputer 3 determines whether or not the voltage of the current detection resistor 17 has reached a predetermined value.

Also, the predetermined non-conducting time T. , _.F is a time determined based on the amount of heating required for the compressor (not shown), and is set to a shorter time as the amount of heating increases. Note that this non-conduction time T. K _F may be changed according to a predetermined reference set in advance based on environmental signals such as the outside air temperature and the compressor temperature.

Then, the above-described energization control is stopped when it is determined that preheating is unnecessary based on the environmental signal or when the operation of the compressor is started, and the normal operation is performed. The rotating state, that is, the road 5 is brought into the rotating state.

In the above-described control example, the first transistor 10 is turned on and off, and the fifth transistor 14 is turned on during that time. However, it is needless to say that other combinations of transistors may be used. For example, the first transistor 10 may be turned on and off, and the sixth transistor 15 may be continuously turned on during that time, and the second transistor 11 may be turned on and off. At the same time, the fourth transistor 13 may be continuously turned on during that time.

Further, as described above, in addition to allowing a current to flow only through a certain combination of transistors, in other words, a certain combination of phases, the combination of phases to be energized may be sequentially changed at predetermined time intervals. In that case, the preheating unevenness is reduced as compared with the case where the specific phase is continuously energized as described above.

In each of the configuration examples described above, the brushless motor 4 has been described as an example of the motor. However, it is not necessary to be limited to this. It can supply power to the coil overnight.

Industrial applicability

As described above, the electric motor preheating device according to the present invention is suitable for use in preheating an electric motor integrated with a compressor constituting a so-called refrigerant cycle in an air conditioner.

Claims

The scope of the claims

1. The switching elements (10, 11, 12, 13, 13, 14, 15) are bridge-connected between the power supply and ground, and the state of the motor (4) that drives the compressor is reduced. A method of controlling power supply in a motor preheating device configured to supply power to the coils (6a, 6b, 6c).

One of the switching elements (10, 11, 12), one end of which is connected to the power supply side, is turned on and off with a predetermined repetition period during a predetermined time, and at the same time, one end is connected to the ground side. Any one of the switching elements (13, 14, 15) is turned on for the predetermined time, and then the current flowing through the stay coils (6a, 6b, 6c) is reduced. An energization control method in a motor preheating device, characterized by repeatedly controlling a corresponding switching element in the reverse direction in the same manner as described above.

2. The switching elements (10, 11, 12, 13, 13, 14, 15) are connected between the power supply and the ground, and the compressor (4) is driven by the compressor. A current supply control method in a motor preheating device configured to supply current to coils (6a, 6b, 6c),

Any one of a plurality of switching elements (10, 11, 12, 13, 14, 14, 15) connected in series between the power supply and the ground. 3, 11 and 14 or 12 and 15), one (10, 11 or 12) is turned on / off at a predetermined repetition cycle, and the other switching element (13 , 14 or 15) in an ON state.

3. The switching elements (10, 11, 12, 13, 13, 14, 15) are connected between the power supply and the earth, and the compressor (4) is driven by the motor. Energizing means (1 and 2) for energizing the overnight coils (6a, 6b, 6c) 2) and

A motor preheating device comprising: a control unit (3) for controlling the operation of the energizing unit.

The control means (3) turns on / off one of the switching elements (10, 11, 12, 12), one end of which is connected to the power supply side, at a predetermined repetition cycle for a predetermined time, Any two of the switching elements (13, 14, 15), one end of which is connected to the ground side, are turned on for the predetermined time, and then the staying coils (6a, 6) are turned on. A motor preheating device characterized by repeatedly controlling the corresponding switching elements in the same manner as described above so that the current flowing in b, 6c) is in the opposite direction.

4. The switching elements (10, 11, 12, 12, 13, 14, and 15) are bridge-connected between the power supply and the ground, and the motor (4) stage that drives the compressor is connected. Energizing means (1 and 2) for energizing the overnight coils (6a, 6b, 6c);

A motor preheating device comprising: control means (3) for controlling the operation of said energizing means (1 and 2);

The control means (3) simultaneously turns on any two of the switching elements (13, 14, 15), one end of which is connected to the ground side, for a predetermined time, and has one end connected to a power supply. One of the switching elements (10, 11, 12, 12) connected to the side is turned on for a predetermined time shorter than the predetermined time, and then the staying coils (6a, 6b, 6c) An electric motor preheating apparatus characterized by repeatedly controlling the corresponding switching element in the same manner as described above so that the current flowing through the electric motor flows in the opposite direction.

5. The motor preheating device according to claim 4, wherein the predetermined time is set so that a power supply current of the motor (4) reaches a predetermined value.

6. Preheating judgment means (20) for judging the necessity of preheating based on a signal about the atmosphere of the compressor inputted from outside,

Heating amount determining means (2 1) for setting the energization period based on a signal about the atmosphere of the compressor input from the outside;

A driving means (23) in which a switching element is bridge-connected between the power supply and the earth to energize a coil of a motor for driving the compressor;

A preheating signal generating means (22) for controlling the operation of the driving means (23) based on each output signal of the preheating determining means (20) and the heating amount determining means (21);

The preheating signal generation means (22) is configured such that one of a plurality of switching elements connected in series between the power supply and the ground is turned on / off at a predetermined repetition cycle. And an operation of the drive means (23) being controlled so that the other switching element is turned on during this time.

7. The motor preheating device according to claim 6, wherein the on time of the switching element to be turned on and off is set so that the motor current reaches a predetermined value.

8. Provide overcurrent detection means (24) for detecting that the current of the motor driving the compressor has reached the overcurrent value.

The preheating signal generating means (22) is a switching element that is turned on and off by the overcurrent detecting means (24) until the time when the current of the motor reaches the overcurrent value is detected. 7. The motor preheating device according to claim 6, wherein the on-time is set to the on time.