WO2006046019A1

WO2006046019A1 - Electricity supply controller

Info

Publication number: WO2006046019A1
Application number: PCT/GB2005/004105
Authority: WO
Inventors: Zia Shlaimoun
Original assignee: Presidio Technology Group Limited
Priority date: 2004-10-26
Filing date: 2005-10-25
Publication date: 2006-05-04
Also published as: GB0423787D0

Abstract

An electricity supply controller for preventing voltage surges from damaging electrical equipment and reducing electricity consumption that can be standalone and within its own enclosure, fitted alongside a mains electricity disconnector, fitted into a consumer unit or a power meter. The device is arranged for connection to an electricity supply, comprising: (i) input connection means arranged for connection to the electricity supply; (ii) output connection means for outputting an electricity supply to a load; and (iii) means located between said input and output for modifying a characteristic of the electricity supply. An example of the means for modifying the characteristic of said electricity supply is means for capping output voltage at a fixed level. The controller is arranged for connection to a single-phase supply voltage and/or connection to a multiple-phase supply voltage.

Description

ELECTRICITY SUPPLY CONTROLLER

The present invention relates to an electricity supply controller and, in particular, an electricity supply controller for preventing voltage surges from damaging electrical equipment and reducing electricity consumption that can be standalone and within its own enclosure, fitted alongside a mains electricity disconnector, fitted into a consumer unit or a power meter.

By way of example, the present invention will now be described in the form of a mains disconnector and/or circuit breaker fitted within a consumer unit.

Consumer units, commonly referred to as fuse boxes, are normally found in domestic premises and some commercial premises. They are designed to control distribution of the single or three-phase electricity supply to various electrical circuits within the site.

A consumer unit normally has a single supply but feeds a number of circuits connected to different types of loads such as lighting, 13 amp outlet sockets and high power appliances such as electric ovens and electric heating systems.

Consumer units are normally fitted with a single mains disconnector and a number of circuit breakers, each supplying one or more circuits.

Should there be an overload condition in any circuit then the circuit breaker feeding that circuit will "trip" and disconnect that circuit from the supply to avoid endangering personnel and damage to the equipment connected to it.

In the event that the circuit breaker fails to disconnect a faulty circuit from the supply, the mains disconnector will trip and disconnect the entire network from the supply. For test and maintenance purposes, both mains disconnector and circuit breaker are fitted with isolation switches that allow the outputs to be manually isolated. The same switch allows the mains disconnector and circuit breaker to be reset after a "trip" disconnection.

In Europe equipment for use with the electricity supply in domestic premises and some commercial premises is rated to operate at 220/230V AC.

However, the European specification for electricity supply to such premises permits variation between 217V AC and 253V AC. In many instances the electricity is supplied towards the higher of these two extremes.

Besides the damage to equipment that a voltage supply higher than the rated voltage of the equipment can cause, there is also the problem that excess electricity is consumed resulting in increased costs and reduced equipment life, even if voltage remains within specification.

The present invention seeks to provide for an electricity supply controller having advantages over known such controllers.

According to an aspect of the present invention, there is provided an electricity supply controller arranged for connection to an electricity supply, comprising: (i) input connection means arranged for connection to the electricity supply; (ii) output connection means for outputting an electricity supply to a load; and (iii) means located between said input and output for modifying a characteristic of said electricity supply.

Advantageously, the controller includes means for causing the electricity supply to bypass said means for modifying the said characteristic of said electricity supply in the event of a fault condition or for purposes of test/measurement and means for interrupting electricity supply through said electricity supply controller from said input to said output in the event of a fault condition and for isolation purposes; Preferably, said means for interrupting electricity supply through said electricity supply controller comprises a first electro-mechanical switch.

In particular, a first actuation means cooperates with said first electro¬ mechanical switch and is biased such that, in normal operation, the electro¬ mechanical switch is in a make position, and electrical current flows through said means for modifying the said characteristic of said electricity supply and from their into the load.

Further, said means for interrupting electricity supply through said electricity supply controller comprises first actuation means for moving said electro-mechanical switch between make and break positions.

An example of the means for modifying the characteristic of said electricity supply is means for capping output voltage at a fixed level. By setting the voltage level output by said controller to match the rated voltage of equipment connected to said controller, the controller not only prevents voltage surges from damaging the equipment, but, because only the voltage that is required to operate the equipment is output by the controller, there is no excess (wasted) power, and the electricity consumption of the equipment is reduced along with the overall cost associated with using the equipment.

Alternatively, said means for modifying the said characteristic of said electricity supply comprises a means for varying a phase angle between a voltage waveform and a current waveform.

In particular, said means for causing the electricity supply to bypass said means for modifying the said characteristic of said electricity supply consists of a means that can detect a fault condition within the said electricity supply controller and can cause electricity supply to bypass said means for modifying the said characteristic of said electricity supply in order to avoid disrupting the electricity supply to equipment connected to said electricity supply controller in the event of a fault condition. Also, said means for causing the electricity supply to bypass said means for modifying the said characteristic of said electricity supply comprises a second electro-mechanical switch.

Conveniently, said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply further comprises second actuation means for moving said electro-mechanical switch between break and make positions.

Preferably, said second actuation means cooperates with said second electro-mechanical switch and is biased such that, in normal operation, the electro-mechanical switch is in a break position, and electrical current does not flow through said means for bypassing the said means for modifying the said characteristic of said electricity supply.

Further, said second actuation means further comprises a latching means arranged for holding said second electro-mechanical switch in a break position during normal operation.

Conveniently, said electricity supply controller further comprises means for controlling operation of said means for interrupting electrical current flow through said electricity supply controller and said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply and thereby allowing for selection of the following operating modes:

(i) activation of said means for interrupting electrical current flow through said electricity supply controller, thereby disconnecting said electricity supply controller from the electricity supply; (ϋ) activation of said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply, thereby engaging a power-save bypass mode; or deactivation of said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply, thereby engaging a power-save mode.

Preferably, said electricity supply controller further comprises status indicators for indicating the status of said means for interrupting electrical current flow through said electricity supply controller and said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply.

Further, said electricity supply controller is powered by said input supply.

In particular, said electricity supply controller is arranged for connection to a single-phase supply voltage.

Alternatively, said electricity supply controller is arranged for connection to a multiple-phase supply voltage.

Conveniently, said multiple-phase supply voltage is a three-phase supply voltage.

Preferably, said electricity supply controller further comprises a temperature sensing means arranged to detect the temperature in said electricity supply controller, wherein an output signal of said temperature sensing means is arranged to control operation of said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply.

Further, in the event of an increased operating temperature within said electricity supply controller, said signal output from said temperature sensing means activates said means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply. Conveniently, said electricity supply controller forms part of an electric circuit mains disconnector.

Alternatively, said electricity supply controller forms part of a circuit breaker.

Further, an electro-mechanical switch of means for interrupting electrical current flow through said electricity supply controller is moveable between make and break positions.

If required, said electro-mechanical switch is latched in a make position during normal operation.

Also, an electro-mechanical switch of means for causing the electrical current to bypass said means for modifying the said characteristic of said electricity supply is moveable between break and make positions.

Preferably, said electro-mechanical switch is latched in a break position during normal operation.

The present invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

Figure 1a illustrates a schematic block diagram of electricity distribution in a home, with main electricity supply controller of the present invention in place of known a mains disconnector;

Figure 1 b illustrates a schematic block diagram of electricity distribution in a home, with secondary electricity supply controllers of the present invention in place of known circuit breakers on some of the electrical circuits;

Figure 2 illustrates a perspective view of an electricity supply controller; Figure 3 illustrates a block diagram representation of the electricity supply controller of Figure 2;

Figure 4 illustrates a schematic circuit diagram of the electricity supply controller of Figure 2 in a first embodiment; and

Figure 5 illustrates a schematic circuit diagram of the electricity supply controller of Figure 2 in a second embodiment.

As mentioned above, Figures 1a & 1 b illustrate an electricity distribution circuit in a home. However, such a circuit could also be in, for example, commercial premises.

In Figure 1a, there is illustrated an electricity supply means 1 (from the mains supply) which is coupled to an electricity meter 2, which, in turn, is coupled to a main electricity supply controller 3 embodying the present invention. Main electricity supply controller 3 is arranged to govern the electricity supply entering the entire electricity distribution circuit of the home. The main electricity supply controller 3 operates to disconnect the electricity distribution circuit (or load circuit) from the mains supply in the event of a fault condition, and also operates to supply a user selected voltage level to the electricity distribution circuit (or load circuit) of the home.

The output of the main electricity supply controller 3 splits to supply (in this example) five household circuits. Before the electricity supply is provided to each one of these five household circuits, the electricity supply must pass through a circuit breaker 4a to 4e associated with the respective household circuit.

In this embodiment of a household circuit, electricity which is output from the main electricity supply controller 3 powers garage lights 5, downstairs lights 6, upstairs lights 7, outlet sockets 8a to 8c, an electric oven 9 and an electric heating system 10. In Figure 1 b, there is illustrated an electricity supply means 1 (from the mains supply) which is coupled to an electricity meter 2, which, in turn, is coupled to a mains disconnector 3. Mains disconnector 3 is arranged to supply the entire electricity distribution circuit of the home. The mains disconnector 3 operates to disconnect the electricity distribution circuit (or load circuit) from the mains supply in the event of a fault condition.

The output of the mains disconnector 3 splits to supply (in this example) five household circuits. Before the electricity supply is provided to each one of these five household circuits, the electricity supply must pass through secondary electricity supply controllers 4a to 4c each embodying the present invention and circuit breakers 4d to 4e associated with the respective household circuit.

In this embodiment of a household circuit, electricity which is output from first secondary electricity supply controller 4a powers garage lights 5 and downstairs lights 6. Similarly, electricity output from the second secondary electricity supply controller 4b supplies upstairs lights 7 and electricity output from the third secondary electricity supply controller 4c supplies outlet sockets 8a to 8c. Circuit breakers 4d and 4e supply an electric oven 9 and an electric heating system 10 respectively.

Figure 2 illustrates the main electricity supply controller 3 in Figure 1a or secondary electricity supply controllers 4a to 4c in Figure 1 b, which comprises a control unit 11 , a power module 19 and a heat-sink 18. The control unit 11 is provided with status indicators 12 to 14, a voltage-setting dial 15 and a mode switch 16.

The voltage-setting dial 15 allows a user to preset the voltage output from the electricity supply controller to a load circuit, and the mode switch 16 is a three-position switch which, in its respective positions, can (i) disconnect the load circuit from the electricity supply; (ii) activate a "power-save" mode of said control unit 11 ; or (iii) de-activate (or bypass) a "power-save" mode of said control unit 11. The status indicators 12 to 14 serve to indicate the status of the control unit 11 , i.e. (i) load circuit disconnected from electricity supply; (ii) "power-save" mode active; or (iii) "power-save" mode inactive.

In this embodiment the status indicators 12 to 14 are light emitting diodes (LEDs), but may be any other suitable type of indicator.

The control unit 11 is also provided with a first automatic actuator (not shown), in the same manner as a circuit breaker, which operates to move said mode switch 16 to a disconnect position in the event of a power surge.

Also, the control unit 11 is provided with a second automatic actuator, which is arranged to move said mode switch 16 to a "power-save" inactive (or bypass) position in the event of a fault, or where the ambient temperature is too high for safe operation of the electricity supply controller 3 (4a to 4e).

In this embodiment, the first and second actuators are separate mechanisms, but in an alternative embodiment, they may be the same mechanism.

Figure 3 illustrates in operational block diagram form the controller of

Figure 2 and which comprises an input connection element A for receiving a supply current from an electricity supply, an interruption element B for interrupting the supply of current through the controller in the event of a fault condition, an element C for modifying a characteristic of the electricity supply so as to achieve some power saving, an element D allowing for bypassing of the modifying element C as required, and an output connection element E for outputting the electricity supply to a load.

Figure 4 illustrates the internal electronic circuit of the control unit 11. The unit is coupled to live and neutral lines 19 and 21 respectively, of an electricity supply, and is arranged to output a controlled electricity supply voltage to a load circuit via live and neutral output terminals 20 and 22 respectively. A power supply unit 23 is provided in said control unit 1 1 to power the respective circuit elements of the control unit 1 1. The power supply lines of the control unit 1 1 are not, however, shown in this figure in order to aid understanding.

Isolator switch 24 is located in the live electricity line prior to a voltage modulator 25. The isolator switch 24 is arranged to disconnect (or "isolate") the voltage modulator 25 from the electricity supply in the event of a fault or overload condition. Such disconnection of the voltage modulator 25 from the electricity supply prevents damage both to the voltage modulator 25 and to the equipment connected to the load circuit.

The voltage modulator 25 is arranged to output a steady voltage level (VOUT) in dependence on a user specified voltage level (VSETPOINT)- The output of said voltage modulator 25 is coupled to a current transformer 26 which, in turn, outputs the consistent voltage level (V_Ouτ) to said live output terminal 20.

A feedback circuit is provided between the input and output terminals (not shown) of said voltage modulator 25. A voltage modulator bypass switch 27 is provided in this circuit, and is arranged either to (i) cause electrical current flow through said control unit 1 1 to bypass the voltage modulator 25, or (ii) cause the electrical current through said control unit 1 1 to flow via the voltage modulator 25.

A first comparator 28 comprises two input terminals, the first of which is coupled to an output of said voltage modulator 25 and arranged to receive the steady voltage level (VOUT). and the second of which is arranged to receive a reference voltage (V_M|_N). The output of said first comparator 28 is arranged to control an actuator (not shown) to operate said voltage modulator bypass switch 27. Therefore, in the event of a fault condition where the steady voltage level (VOUT) falls below a predetermined level (i.e. below the reference voltage VMIN), the output signal from the first comparator 28 ensures that the voltage modulator bypass switch 27 is in the "power-save" inactive (or bypass) state, and the electrical current flow through the control unit 11 bypasses the voltage modulator 25 by means of the feedback circuit.

Of course, in an alternative arrangement, the reference voltage may be a maximum voltage (V_MAX), which the steady voltage level (V_Ouτ) must not exceed.

A second comparator 29 comprises two input terminals, the first of which is arranged to receive an output of said voltage modulator 25 and to receive the steady voltage level (VOUT). and the second of which is arranged to receive a user specified voltage level (VSET_PO_INT). The user specified voltage level (VSETPOINT) can be varied by a user via operation of the voltage-setting dial 15 of Figure 2. A signal output by said second comparator 29 is supplied to said voltage modulator 25 to control the operation thereof.

The control unit 11 is also provided with a third comparator 30, the first input terminal of which is arranged to receive a signal indicating the value of the current (l_Ouτ) through said current transformer 26, and the second input terminal of which is arranged to receive a reference current value (IMAX)- A signal output by said third comparator is arranged to control an actuator (not shown) to operate said isolator switch 24. Therefore, in the case where an overload condition occurs (i.e. when the current passing through current transformer 26 (IOUT) is greater than the reference current value (IM_AX)), the third comparator 30 outputs a signal indicative of this fault, which causes said actuator (not shown) to move said isolator switch 24 to a position whereby the voltage modulator 25 (and the load circuit) are disconnected from the electricity supply.

In the above embodiment, the actuators are of a known type used in circuit breakers. The actuators are spring-loaded and are held in a position by a latch, which is triggered when one of the above mentioned fault conditions occurs. The actuators further comprise an electro-mechanical means which is arranged to reset the actuator when the fault condition is cleared. Figure 5 illustrates the internal electronic circuit of the control unit 11 in a second embodiment. Like reference numerals are used to refer to parts which correspond to parts previously described in relation to Figure 3.

The control unit 11 of Figure 5 is arranged to monitor the "power factor" of the load and adjust the phase angle between the voltage and current by modulating the voltage waveform delay.

It can be seen from Figure 5 that the control unit 11 of the second embodiment is similar to the control unit of the first embodiment, except that in this circuit, a switching device 31 replaces the voltage modulator 25, and a alternative second comparator 32 replaces the second comparator 29 of the first embodiment.

The alternative second comparator 32 comprises two input terminals, the first of which is arranged to receive an output of said switching device 31 , and the second of which is arranged to receive a signal indicating the value of the current (IOUT) through said current transformer 26.

In the present embodiment, the control unit 11 is arranged to monitor power factor by way of the alternative second comparator 32 connected between the output voltage and output current waveforms. The output of the alternative second comparator 32 is used to drive the switching device 31 to adjust the voltage waveform delay.

As the power factor decreases the control unit 11 is arranged to increase the phase angle by increasing the voltage waveform delay. As the power factor increases, the control unit 11 is arranged to reduce the phase angle by decreasing the voltage waveform delay.

Maximum power saving is achieved when the power factor is large. In the second embodiment, the switching device 31 comprises a thyristor, but in alternative arrangements, other suitable means could be substituted in place of the thyristor.

In a further arrangement, the actuator which controls the voltage modulator bypass switch 27 is arranged such that in normal operation, it is latched in the "power-save" active mode. If the electricity supply to the control unit 11 is interrupted, the actuator which controls the voltage modulator bypass switch 27 is arranged to "trip" to the "power-save" inactive (or bypass) mode.

Such an arrangement is advantageous in that during such times when power supplied to the control unit 11 is interrupted and then restored, the control unit 11 requires more power during the "power-up" phase immediately after the restoration of power. During this phase, the control unit 11 draws the maximum current from its power supply and it is, therefore, beneficial if the control unit 11 is devoting all of its resources to achieving operational readiness, so that such a state is reached in as short a time as possible. Therefore, by bypassing the voltage modulator 25, the control unit 11 achieves this goal. Once operational readiness has been achieved, the actuator then resets itself to the "power-save" active mode.

In an alternative arrangement, the control unit 11 includes a temperature sensor, which is arranged to detect for a high operating temperature in said control unit 11. Detection of a high operating temperature indicates a fault, and the temperature sensor may be arranged to operate an actuator to engage the "power-save" inactive mode in such circumstances. Once such a fault has cleared (as indicated by a signal output by the temperature sensor), the actuator resets to the "power-save" active mode.

In a further alternative arrangement, the actuators are arranged such that in the event of power-loss to the control unit 11 , the control unit 11 defaults to a certain state (e.g. disconnected from mains electricity supply). In yet a further alternative arrangement, the actuators are controlled by a remote system, thereby allowing remote control and monitoring of the control unit 11.

In an alternative arrangement of the first embodiment, the voltage modulator 25 may comprise a voltage control device as disclosed in the applicant's previous application number WO 2004/004107. The voltage control device comprises means for comparing the output voltage of the voltage control device with a predetermined voltage, and generating a comparison signal. The voltage control device also comprises a means to adjust the output voltage in response to the comparison signal, said means being connected to the input and output of the voltage control device. The output voltage is maintained substantially at the predetermined voltage. The means to adjust the output voltage may comprise means to delay the onset of the rise of output voltage within one half-cycle, where the means to delay is preferably a thyristor.

Claims

1 ) An electricity supply controller for connection to an electrical supply having an alternating supply voltage, the device comprising: a. input connection means arranged for connection to the electricity supply; b. an output connection means for outputting an electricity supply to a load; c. means located between said input and output for modifying a characteristic of said electricity supply

2) A device according to claim 1 having means to modify characteristic of said electricity supply in order to reduce supply voltage to a preset level

3) A device according to claim 2 which is standalone, installed within its own enclosure 4) A device according to claim 2 which is fitted alongside a mains electricity disconnector within an enclosure

5) A device according to claim 2 which replaces a mains disconnector within a consumer unit

6) A device according to claim 2 which replaces a circuit breaker within a consumer unit

7) A device according to claim 2 which is fitted into an electricity power meter

8) A device according to any preceding claim which incorporates a bypass facility that causes the electricity supply to bypass the means for modifying the electricity supply

9) A device according to any preceding claim which incorporates a disconnect facility which interrupts the electrical current flow between input and output in the event of a predefined condition

10)A device according to any preceding claim which incorporates a single means to bypass and disconnect

11 )A device according to any preceding claim which is powered by the input voltage 12)A device according to any preceding claim for connection to a single phase supply voltage 13)A device according to any preceding claim for connection to multiple phase supply voltages 14)A device according to the preceding claim wherein the multiple phase supply voltage is three phase 15)A device according to any preceding claim which incorporates a voltage setting dial 16)A device according to any preceding claim which incorporates status indicators

17)A device according to any preceding claim which incorporates a reset facility for the bypass facility

18)A device according to any preceding claim which incorporates a reset facility for the disconnect facility 19)A device according to any preceding claim which incorporates a single reset facility for both the bypass and disconnect facilities