JP6936601B2 - Power supply device - Google Patents

Description

The present invention relates to a power supply device capable of reducing the no-load loss of transformers when a plurality of transformers are connected in parallel and connected to a load.

Transformers installed in buildings and factories are selected to have the capacity to supply the maximum demand power throughout the year. In general, a plurality of transformers are installed depending on the constraints of the electric power company and the building.

In addition, Patent Document 1 describes that the number of transformers in operation is controlled by introducing fuzzy inference using the moving average value of each load current flowing through at least a plurality of transformers arranged in parallel.

Japanese Unexamined Patent Publication No. 5-300569

By the way, in order to realize ZEB (Zero Energy Building), it is important to reduce the loss of the transformer. However, in the transformer operation number control described in Patent Document 1, the circuit breaker on the primary side of each transformer is used. Remains closed and each transformer is constantly experiencing no-load loss.

The present invention has been made in view of the above, and provides a power supply device capable of reducing the no-load loss of transformers when a plurality of transformers are connected in parallel and connected to a load. The purpose.

In order to solve the above-mentioned problems and achieve the object, the power supply device according to the present invention is connected to the first transformer which is connected to the power source and supplies the voltage-converted power to the load, and is connected to the power source. A second transformer connected in parallel to the first transformer to supply voltage-converted power to the load, and a first primary side contactor connected to the primary side of the first transformer. A first secondary contactor connected to the secondary side of the first transformer, and a second primary contactor connected to the primary side of the second transformer. The second secondary contactor connected to the secondary side of the second transformer, and the first primary contactor and the first secondary contactor when the predicted power amount is equal to or less than a predetermined value. The side contactor is closed and the second primary side contactor and the second secondary side contactor are opened to disconnect the second transformer, and the predicted power amount exceeds a predetermined value. In this case, the first primary contactor and the first secondary contactor are closed, and the second primary contactor and the second secondary contactor are closed. It is characterized by including a control unit that controls opening and closing to turn on a second transformer.

Further, the power supply device according to the present invention is connected to a first transformer that is connected to a power source and supplies voltage-converted power to a load, and is connected to the power source and is connected in parallel to the first transformer. A second transformer that supplies voltage-converted power to the load, a switch connected to the primary side of the first transformer, and a primary connected to the primary side of the second transformer. When the predicted power amount is equal to or less than a predetermined value with the side contactor, the secondary side contactor connected to the secondary side of the second transformer, and the switch closed, the secondary side contact Control that opens and closes the second transformer to disconnect the second transformer, and when the predicted power amount exceeds a predetermined value, closes the secondary contactor and turns on the second transformer. It is characterized by having a part and.

Further, in the power supply device according to the present invention, in the above invention, when the control unit turns on the second transformer more than a predetermined number of times within a predetermined period, then until the end of the predetermined period. The second transformer is turned on.

Further, in the power supply device according to the present invention, in the above invention, the control unit is the first transformer or the first transformer having a short integrated operation time when the first transformer or the second transformer is turned on. The second transformer is selected and turned on, and the first transformer or the second transformer having a long integrated operation time when the first transformer or the second transformer is disconnected is selected. It is characterized in that it is arranged in a row.

Further, in the power supply device according to the present invention, in the above invention, when the control unit has a plurality of the second transformers, the second transformer has a short integrated operation time when the second transformer is turned on. The second transformer is selected and turned on, and the second transformer having a long integrated operation time is selected and disconnected when the second transformer is disconnected.

Further, the power supply device according to the present invention is characterized in that, in the above invention, the predicted electric energy is a predicted average value for each predetermined division time based on past results including meteorological data.

According to the present invention, when a plurality of transformers are connected in parallel and connected to a load to control the number of transformers, the primary contactor of the transformer to be disconnected is open, so that a plurality of transformers are connected. The no-load loss of the transformer can be reduced.

FIG. 1 is a block diagram showing a configuration of a power supply device according to a first embodiment of the present invention. FIG. 2 is a flowchart showing a procedure for controlling the number of transformers by the control unit shown in FIG. FIG. 3 is a diagram showing an example of transformer number control by the control unit shown in FIG. FIG. 4 is a flowchart showing a procedure for controlling the number of transformers by the control unit of the power supply device according to the second embodiment of the present invention. FIG. 5 is a flowchart showing a procedure for controlling the number of transformers by the control unit of the power supply device according to the third embodiment of the present invention. FIG. 6 is a block diagram showing a configuration of a power supply device according to a fourth embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a power supply device 1 according to a first embodiment of the present invention. As shown in FIG. 1, the power supply device 1 supplies power supplied from the power supply 2 via the power line 3 to the load 6 via two transformers 4 and 5 connected in parallel. Contactors C11 and C12, which are magnetic contactors, are connected to the primary side and the secondary side of the transformer 4, respectively. Contactors C21 and C22, which are magnetic contactors, are connected to the primary side and the secondary side of the transformer 5, respectively. Transformers 4 and 5 have, for example, an equal capacity capable of supplying 1/2 of the maximum demand power of the load 6. Transformers 4 and 5 are, for example, three-phase transformers, have a capacity of 500 kVA, and have a primary side voltage of 6600 V and a secondary side voltage of 210 V. Further, for example, the contactors C11 and C21 on the primary side are vacuum electromagnetic contactors because they have a high pressure.

The power supply device 1 has a control unit 10. The control unit 10 holds in the database 12 the measured values from the wattmeter 11 that measures the electric power supplied from the power source 2 to the load 6 via the power line 3. The control unit 10 is connected to the contactors C11, C12, C21, and C22 via the interface 13. The control unit 10 obtains the predicted electric energy such as annual, monthly, and daily based on the measured value (measured value) stored in the database 12. In particular, the control unit 10 calculates the predicted electric energy transition of the day based on the meteorological data Da acquired from the network N such as the Internet and the measured value held in the database 12, and calculates the calculated predicted electric energy transition. Based on this, the opening and closing of the contactors C11, C12, C21, and C22 is controlled. That is, the control unit 10 controls the number of transformers 4 and 5 by turning on and disconnecting the transformers 4 and 5 based on the predicted electric energy. The control unit 10 and the database 12 function as an energy monitoring / control system (BEMS: Building Energy Management System).

Here, the procedure for controlling the number of transformers by the control unit 10 will be described with reference to the flowchart shown in FIG. As shown in FIG. 2, first, the control unit 10 calculates the daily predicted electric energy transition (step S101). For example, the predicted electric energy transition line L shown in FIG. 3 is calculated.

After that, the control unit 10 determines whether or not there is a time zone in which the predicted electric energy T exceeds the rated value T1 of the transformers 4 and 5 in the transition of the predicted electric energy (step S102). When there is a time zone in which the predicted electric energy T exceeds the rated value T1 of the transformers 4 and 5 (steps S102 and Yes), the parallel operation mode using the two transformers 4 and 5 is set (step S103). On the other hand, when there is no time zone in which the predicted electric energy T exceeds the rated value T1 of the transformers 4 and 5 (steps S102 and No), the mode is set to the independent operation mode in which only one transformer 4 or the transformer 5 is used. (Step S104).

When the parallel operation mode is set (step S103), for example, the transformer 4 is turned on. When the transformer 4 is turned on, the contactors C11 and C12 are closed, and the contactors C21 and C22 are opened to disconnect the transformer 5.

After that, the predicted electric energy T of the predetermined division time Δt is acquired (step S105). For example, the predetermined division time Δt is 30 minutes, and the predicted electric energy T of the next section is acquired from the present time. After that, it is determined whether or not the predicted electric energy T exceeds the first predetermined value Tn (step S106). The first predetermined value Tn is the predicted power amount at which the transformers 4 and 5 have the maximum efficiency.

When the predicted electric energy T does not exceed the first predetermined value Tn (steps S106, No), it is determined whether or not the day has ended (step S107). If one day is not completed (steps S107 and No), the process proceeds to step S105 to maintain the state in which one transformer is turned on. On the other hand, when one day has ended (steps S107, Yes), the process proceeds to step S101, the calculation process of the daily predicted electric energy transition is performed, and the above-mentioned process is repeated.

On the other hand, when the predicted electric energy T exceeds the first predetermined value Tn (step S106, Yes), the second transformer is turned on (step S111). In this case, the contactors C11 and C12 are closed, and the open contactors C21 and C22 are closed.

When the independent operation mode is set (step S104), for example, the transformer 4 is turned on. When the transformer 4 is turned on, the contactors C11 and C12 are closed, and the contactors C21 and C22 are opened to disconnect the transformer 5.

After that, the predicted electric energy T of the predetermined division time Δt is acquired (step S108). For example, the predetermined division time Δt is 30 minutes, and the predicted electric energy T of the next section is acquired from the present time. After that, it is determined whether or not the predicted electric energy T exceeds the second predetermined value Ta (step S109). The second predetermined value Ta is larger than the first predetermined value Tn and is a value obtained by subtracting the predetermined margin ΔT from the rated value T1. Using the second predetermined value Ta in the independent operation mode is highly likely to be able to cover the amount of power supplied by inputting only one transformer from the daily predicted power amount transition, and as much as possible, two units. This is to prevent the eye transformer from being turned on.

When the predicted electric energy T does not exceed the second predetermined value Ta (steps S109, No), it is determined whether or not the day has ended (step S110). If one day is not completed (steps S110, No), the process proceeds to step S108 to maintain the state in which one transformer is turned on. On the other hand, when one day has ended (steps S110, Yes), the process proceeds to step S101, the calculation process of the daily predicted electric energy transition is performed, and the above-mentioned process is repeated.

On the other hand, when the predicted electric energy T exceeds the second predetermined value Ta (step S109, Yes), the second transformer is turned on (step S111). In this case, the contactors C11 and C12 are closed, and the open contactors C21 and C22 are closed.

After turning on the second transformer in step S111, the predicted electric energy T of the next predetermined division time Δt is further acquired (step S112). After that, it is determined whether or not the predicted electric energy T exceeds the first predetermined value Tn (step S113). When the predicted electric energy T exceeds the first predetermined value Tn (step S113, Yes), it is determined whether or not the day has ended (step S115). If one day is not completed (steps S115, No), the process proceeds to step S112 to maintain the state in which the two transformers are turned on. On the other hand, when one day has ended (steps S115, Yes), the process proceeds to step S101, the calculation process of the daily predicted electric energy transition is performed, and the above-mentioned process is repeated.

On the other hand, when the predicted electric energy T does not exceed the first predetermined value Tn (steps S113 and No), one transformer that has been turned on is disconnected (step S114). For example, the transformer 5 is disconnected. The arrangement of the transformer 5 is to open the contactors C21 and C22.

After that, the predicted electric energy T for the next predetermined division time Δt is further acquired (step S116). After that, it is determined whether or not the predicted electric energy T exceeds the second predetermined value Ta (step S117). When the predicted electric energy T exceeds the second predetermined value Ta (steps S117, Yes), the process proceeds to step S111 and the state in which one transformer is turned on is maintained. On the other hand, when the predicted electric energy T does not exceed the second predetermined value Ta (step S117, No), it is determined whether or not the day has ended (step S118). If the day has not ended (steps S118 and No), the process proceeds to step S116 to maintain the state in which one transformer is turned on. On the other hand, when one day has ended (steps S118, Yes), the process proceeds to step S101, the calculation process of the daily predicted electric energy transition is performed, and the above-mentioned process is repeated.

FIG. 3 is a diagram showing an example of controlling the number of transformers by the control unit 10. In FIG. 3, since there is a time zone in which the daily predicted electric energy transition exceeds the rated value T1, the parallel operation mode is set. Then, at the start time t0, one transformer is turned on, and since the first predetermined value Tn is exceeded at the time point t1, two transformers are turned on and operated after the time point t1. At present, ta exceeds the first predetermined value Tn, so two transformers are turned on and operated. The operation plan will be made after the current ta, but since it will be the first predetermined value Tn or less at the time t2, one transformer will be disconnected and the operation will be performed by only one transformer. As described above, when the daily predicted electric energy transition is equal to or less than the rated value T1, the second predetermined value Ta is used instead of the first predetermined value Tn.

In the first embodiment described above, when the transformers 4 and 5 are disconnected, no voltage is applied to the transformers 4 and 5, and no load loss (iron loss) occurs. Therefore, the transformers 4 and 5 do not occur. It is possible to reduce the no-load loss when operating the.

(Embodiment 2)
FIG. 4 is a flowchart showing a procedure for controlling the number of transformers by the control unit 10 of the power supply device 1 of the second embodiment. In the second embodiment, when the transformer is turned on and off, the integrated operation time of the transformer is taken into consideration to extend the life of the transformer.

Specifically, as shown in FIG. 4, the integrated operation time when the first transformer is turned on after the parallel operation mode is set in step S103 and after the independent operation mode is set in step S104. Selects a short transformer (steps S105a, S108a) and inputs this selected transformer as the first transformer.

Further, as shown in FIG. 4, when disassembling the transformer in step S114, a transformer having a long integrated operation time is selected (step S114a), and the selected transformer is disengaged.

Other control processes are the same as those in the first embodiment, and the same parts are designated by the same reference numerals.

When three or more transformers are installed in parallel, the transformer having the shortest integrated operation time is selected in steps S105a and S108a, and the transformer having the longest integrated operation time is selected in step S114a.

(Embodiment 3)
FIG. 5 is a flowchart showing a procedure for controlling the number of transformers by the control unit 10 of the power supply device 1 of the third embodiment. In the third embodiment, when the number of times the transformer is turned on exceeds a predetermined number of times, the transformer number control process is stopped so that the current state of the transformer turned on is maintained, and the contactor is turned on and off. The deterioration of C11, C12, C21 and C22 is prevented.

Specifically, as shown in FIG. 5, it is determined whether or not the number of times of turning on the second transformer in step S111 is set to a predetermined number of times, for example, once or more (step S112b). .. If the number of times of input per day is not more than a predetermined number (step S112b, No), the process proceeds to step S112. On the other hand, when the number of times of input per day becomes a predetermined number or more (step S112b, Yes), the process proceeds to step S112a, and it is determined whether or not the day has ended. If one day is not completed (steps S112a, No), the process proceeds to step S112b to maintain the current transformer-on state. On the other hand, when one day is completed (step S112a, Yes), the process proceeds to step S101, the calculation process of the daily predicted electric energy transition is performed, and the above-described process is repeated.

Other control processes are the same as those in the first embodiment, and the same parts are designated by the same reference numerals.

(Embodiment 4)
FIG. 6 is a block diagram showing a configuration of the power supply device 1a according to the fourth embodiment of the present invention. In the fourth embodiment, the switch C31 with a fuse is connected only to the primary side of the transformer 4 instead of the contactors C11 and C12 in the first to third embodiments. The switch C31 is, for example, an LBS (Load Break Switches). Other configurations are the same as those of the first to third embodiments. Since the switch C31 is always closed and turned on, the no-load loss of the transformer 4 cannot be eliminated, but the transformer 5 is turned on and off by opening and closing the contactors C21 and C22, and the transformer is turned on. No load loss occurs when the sequence of 5 is arranged.

In the fourth embodiment, only the closing and disconnecting of the transformer 5 are controlled. However, when a plurality of transformers 5 are present, the control processing of the above-described first to third embodiments is applied.

Further, in the above-described first to third embodiments, two transformers 4 and 5 have been described as an example of transformers connected in parallel, but control of the number of three or more transformers is also applied in the same manner. Can be done. In this case, a plurality of first predetermined value Tn, second predetermined value Ta, etc. are set according to the number of transformers input. Here, the transformer 4 (first transformer) and the transformer 5 (second transformer) are connected to the contactors C11 and C21 having the same function on the primary side, respectively, and are connected to the secondary side, respectively. Since the contactors C12 and C22 having the same function are connected to each other, the first transformer and the second transformer are equivalent. Therefore, when three or more transformers are connected in parallel, select a transformer with a short integrated operating time when turning on the transformer, and select a transformer with a long integrated operating time when disassembling the transformer. Will be untied.

Further, in the fourth embodiment, the number of transformers 4 (first transformer) to which only the switch C31 is connected and the number of transformers 5 (second transformer) to which the contactors C21 and C22 are connected. Is arbitrary, and at least one transformer 5 to which the contactors C21 and C22 are connected may be connected in parallel. When a plurality of transformers 5 to which the contactors C21 and C22 are connected are installed, the transformer 5 having a short integrated operation time is selected and input when the transformer 5 is turned on, and the integrated operation time is set when the transformer 5 is disconnected. Will select and disconnect the long transformer 5.

Further, in the above-described first to fourth embodiments, the first predetermined value Tn and the second predetermined value Ta are used, and different predetermined values (first predetermined value Tn, second predetermined value) are used in the parallel operation mode and the independent operation mode. Although Ta) was used, it may be controlled by using the same predetermined value. For example, the second predetermined value Ta may be set to the first predetermined value Tn for control. Further, the predetermined value may be set by hysteresis control in which a large predetermined value is set when the transformer is turned on and a small predetermined value is set when the transformer is disconnected.

The elements in the above-described embodiments 1 to 4 can be appropriately combined.

1,1a Power supply device 2 Power supply 3 Power line 4, 5 Transformer 6 Load 10 Control unit 11 Power meter 12 Database 13 Interface C11, C12, C21, C22 Contactor C31 Switch Da Meteorological data L Predicted electric energy transition line N Network T Predicted electric energy T1 Rated value Ta Second predetermined value Tn First predetermined value Δt Predetermined division time

Claims (6)

The first transformer, which is connected to the power supply and supplies the voltage-converted power to the load,
A second transformer having the same rated value as the first transformer , connected to the power supply, and connected in parallel to the first transformer to supply voltage-converted power to the load.
With the first primary contactor connected to the primary side of the first transformer,
With the first secondary side contactor connected to the secondary side of the first transformer,
A second primary contactor connected to the primary side of the second transformer,
A second secondary contactor connected to the secondary side of the second transformer,
The transition of the predicted electric energy in the control target period is obtained based on the actual electric energy for each predetermined division time, and when the transition of the predicted electric energy exceeds the rated value, the first transformer and the second transformer are used. Initially set to the parallel operation mode in which the transformers are operated in parallel, and if the rated value is not exceeded, the first transformer is initially set in the independent operation mode in which the first transformer is operated independently, and then the prediction after the predetermined division time from the present time. When the electric energy is acquired and the predicted electric energy exceeds the first predetermined value smaller than the rated value in the parallel operation mode, the first primary contactor and the first secondary contactor The second primary side contactor and the second secondary side contactor are closed and the second transformer is turned on, and the predicted electric energy exceeds the first predetermined value. If not, close the first primary contactor and the first secondary contactor, and open the second primary contactor and the second secondary contactor. The second transformer is disconnected to shift to the independent operation mode, and in the independent operation mode, the predicted electric energy exceeds the second predetermined value which is larger than the first predetermined value and smaller than the rated value. In this case, the first primary contactor and the first secondary contactor are closed, and the second primary contactor and the second secondary contactor are closed. When the second transformer is turned on to shift to the parallel operation mode and the predicted electric energy does not exceed the second predetermined value, the first primary contact and the first secondary contact A control unit that closes the vessel and opens the second primary contactor and the second secondary contactor to perform open / close control for disconnecting the second transformer.
A power supply device characterized by being equipped with. The first transformer, which is connected to the power supply and supplies the voltage-converted power to the load,
A second transformer having the same rated value as the first transformer , connected to the power supply, and connected in parallel to the first transformer to supply voltage-converted power to the load.
A switch connected to the primary side of the first transformer and
With the primary side contactor connected to the primary side of the second transformer,
A secondary contactor connected to the secondary side of the second transformer,
The transition of the predicted power amount in the control target period is obtained based on the actual power amount for each predetermined division time, and when the transition of the rated value exceeds the rated value, the first transformer and the second transformer Is initially set to the parallel operation mode in which the first transformer is operated in parallel, and when the rated value is not exceeded, the first transformer is initially set to the independent operation mode in which the first transformer is operated independently. When the amount is acquired and the predicted power amount exceeds the first predetermined value smaller than the rated value in the parallel operation mode, the primary side contactor and the secondary side contact are made with the switch closed. When the second transformer is turned on with the switch closed and the predicted power amount does not exceed the first predetermined value, the primary contact and the secondary contact are made with the switch closed. The second transformer is opened and the second transformer is disconnected to shift to the independent operation mode. In the independent operation mode, the predicted power amount is larger than the first predetermined value and smaller than the rated value. 2 When the value exceeds a predetermined value, the primary contactor and the secondary contactor are closed with the switch closed, the second transformer is turned on, and the mode shifts to the parallel operation mode. When the predicted power amount does not exceed the second predetermined value, the primary side contactor and the secondary side contactor are opened with the switch closed, and the second transformer is disconnected. A control unit that controls opening and closing,
A power supply device characterized by being equipped with. The control unit is characterized in that, when the number of times the second transformer is turned on is equal to or greater than the predetermined number of times within a predetermined period, the second transformer is turned on until the end of the predetermined period. The power supply device according to claim 1 or 2. The control unit selects and turns on the first transformer or the second transformer, which has a short integrated operation time when the first transformer or the second transformer is turned on, and turns on the first transformer. The invention according to claim 1 or 3, wherein when the transformer or the second transformer is disconnected, the first transformer or the second transformer having a long integrated operation time is selected and disconnected. Power supply device. When there are a plurality of the second transformers, the control unit selects and turns on the second transformer having a short integrated operation time when the second transformer is turned on, and turns on the second transformer. The power supply device according to claim 2 or 3, wherein the second transformer having a long integrated operation time is selected and disconnected at the time of arrangement. The power supply device according to any one of claims 1 to 5, wherein the predicted electric energy is a predicted average value for each predetermined division time based on past results including meteorological data.

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