JP2020114146A - Power feeding system - Google Patents

Abstract

To provide a power feeding system that can calculate a charging power instruction value within a range not exceeding contracted power.SOLUTION: A charging controller 50 calculates the allocated power amount per control unit time from a control unit time that divides a unit time of contract power per unit time, calculates the integrated power amount per control unit time by a power meter 22 and the power amount per control unit time to a device 40 other than a plurality of chargers from the total charging power amount per control unit time to a plurality of chargers 30 and 31, and calculates the total chargeable power amount per control unit time from the allocated power amount per control unit time and the power amount per control unit time to the device 40 other than the plurality of chargers, and determines a charging power instruction value for the plurality of chargers 30 and 31 in the control unit time from the present time on the basis of the total chargeable electric energy.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power feeding system.

In the charging power control system disclosed in Patent Document 1, in an environment in which a plurality of chargers operate simultaneously with electric equipment other than the charger, a plurality of remaining electric power ranges excluding the electric power used by other electric equipment Efficient charging with the charger. For that purpose, the power consumption by the electric equipment other than the charger is measured, and the power consumption by each charger is also measured. Then, the allocated power to the charger is determined based on the power consumption by other chargers and electric equipment other than the charger and the conversion efficiency of the AC/DC converter, and the charger notifies the allocated power. Then, the charging current to be supplied to the connected secondary battery is determined within a range not exceeding the allocated power.

WO2012/118184

By the way, in order to prevent the contract power from being exceeded by controlling the electric power of the charger that charges the electric vehicle, it is necessary to establish a specific calculation method of the charging power instruction value.
An object of the present invention is to provide a power supply system that can calculate a charging power instruction value in a range that does not exceed contracted power.

A power supply system for solving the above problems includes a power amount acquisition unit that acquires the amount of power supplied from a power system, and a plurality of units connected to the power system for charging a vehicle equipped with a storage battery. And a device other than the plurality of chargers connected to the power system, the power supply system having a charge controller for controlling charge power to the plurality of chargers, the charge controller Calculates the allocated power amount per control unit time from the control unit time that divides the unit time for the contract power per unit time, and calculates the integrated power amount per control unit time by the power amount acquisition unit and the plurality of units. Calculating the amount of power per unit control time to the devices other than the plurality of chargers from the total amount of charging power per unit control time to the charger, and further assigning the amount of power per unit control time and the plurality of The total rechargeable power amount per control unit time is calculated from the power amount per control unit time to devices other than the charger, and based on the total rechargeable power amount, the plurality of chargers in the control unit time from the present time The point is to determine the charging power instruction value for the battery.

According to this, the allocated power amount per control unit time is calculated from the control unit time that divides the unit time of the contract power per unit time. The electric energy per control unit time to the devices other than the plural chargers is calculated from the integrated electric energy per control unit time by the electric energy acquisition unit and the total charging electric energy per control unit time to the plurality of chargers. .. Further, the total rechargeable power amount per control unit time is calculated from the allocated power amount per control unit time and the power amount per control unit time to devices other than the plurality of chargers, and based on the total rechargeable power amount. Then, the charging power instruction values for the plurality of chargers in the control unit time from the present time are determined. Therefore, it is possible to calculate the charging power instruction value in a range that does not exceed the contracted power.

In the power supply system, the charge controller calculates an error power amount per control unit time from the allocated power amount per control unit time and the integrated power amount per control unit time, and calculates the total chargeable power amount The error power amount may be added at the time of calculation, and the added error power amount may be reset when the unit time of the contract power per unit time has elapsed.

Further, in the power supply system, the charge controller may set a predetermined set value as the total rechargeable power amount for the first time after the reset or a total rechargeable power amount immediately before the reset.

According to the present invention, it is possible to calculate the charging power instruction value in a range that does not exceed the contracted power.

The block diagram which shows a power feeding system. 6 is a flowchart for explaining the operation of the first embodiment. The figure which shows the transition of electric power. The figure which shows the transition of electric power. The flowchart for demonstrating the effect|action of 2nd Embodiment. The figure which shows the transition of electric power. The figure which shows the transition of electric power. The figure which shows the transition of the integrated electric energy reading value and charger electric energy within the range of contract electric power.

(First embodiment)
An embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the present embodiment assumes a charging stand capable of charging a plurality of electric forklift trucks (vehicles indicated by reference numerals 60 and 70 in the figure) in a factory. The power supply system 10 includes a plurality of chargers 30 and 31 and a device 40 other than the plurality of chargers. The charger 30 is connected to the electric power system and is for charging the vehicle 60 equipped with the storage battery 61. The charger 31 is connected to the electric power system and charges the vehicle 70 equipped with the storage battery 71. The devices 40 other than the plurality of chargers are connected to the power system.

The electric power of the electric power system is sent to the plurality of chargers 30 and 31 and the device 40 other than the plurality of chargers via the relay device 21. The relay device 21 includes a cubicle and a distribution board. The relay device 21 and the plurality of chargers 30 and 31 are connected by a power supply line L10, and the electric power of the power system is sent to the plurality of chargers 30 and 31 via the power supply line L10 to be used for charging the storage battery of the vehicle. To be done. Further, the relay device 21 and the devices 40 other than the plurality of chargers are connected by a power supply line L11, and the power of the power system is sent to the devices 40 other than the plurality of chargers via the power supply line L11. It is used to drive devices 40 other than the charger.

The electric energy meter 20 of the electric power company measures the amount of electric power sent from the electric power system to the relay device 21.
The power feeding system 10 includes a power meter 22 and a charging controller 50 that controls charging power for the plurality of chargers 30 and 31. The measurement result of the integrated electric energy is sent from the electric energy meter 20 to the electric energy measuring device 22 by a pulse. The electric energy measuring device 22 as the electric energy acquisition unit measures the electric energy Pk supplied from the electric power system, that is, the integrated electric energy (system) Pk.

An electric energy Pk per unit time is sent from the electric energy measuring device 22 to the charging controller 50. Contract power information is sent to the charging controller 50, and the charging controller 50 acquires the contract power (quantity) Pc.

The charge controller 50 and the chargers 30 and 31 are communicatively connected by a communication line L20. Charging power information is sent from the chargers 30 and 31 to the charging controller 50 via the communication line L20, and the charging controller 50 acquires the charging power information from the chargers 30 and 31. The charging controller 50 sends the charging power instruction value to each of the chargers 30 and 31 via the communication line L20. For example, when the device 40 other than the plurality of chargers needs a large amount of power, the charging power by the plurality of chargers 30 and 31 is reduced so as not to exceed the contracted power. Each of the chargers 30 and 31 charges the storage battery of the vehicle according to the charging power instruction value from the charging controller 50.

Next, the operation will be described.
In FIG. 3, the horizontal axis represents time and the vertical axis represents electric energy. In the horizontal axis of FIG. 3, the present, -Tc before the control unit time Tc before the present, -Tc before the present control unit time Tc twice, and before the present control unit time Tc three times the present control unit time Tc. -3Tc and Tc after the control unit time Tc with respect to the present. On the vertical axis of FIG. 3, the assigned power amount per control unit time is represented by Pct, and the power amount per control unit time to the devices 40 other than the plurality of chargers is represented by Pot. Further, the total charging power amount per control unit time to the plurality of chargers 30 and 31 is represented by Pjt, the total chargeable power amount per control unit time is represented by Pjat, and the total charging power amount per control unit time by the power amount measuring unit 22 is represented. The integrated electric energy (system) of is represented by Pkt.

The charge controller 50 executes the process shown in FIG. In the present embodiment, as shown in FIG. 4, the contract power Pc per unit time Tpc is, for example, 3000 kWh/60 minutes. In the present embodiment, the control unit time Tc for dividing the unit time Tpc is, for example, 1 minute. That is, for example, for the contracted power Pc per unit time Tpc, the control unit time Tc divides the unit time Tpc into 60.

As shown in FIG. 2, in step S100, the charging controller 50 controls the contracted power Pc per unit time, the integrated power amount (system) Pk, and the total amount of charged power per unit time for controlling the plurality of chargers 30 and 31. Get Pjt.

As shown in FIG. 2, in step S101, the charging controller 50 allocates the control unit time Tc from the control unit time Tc that divides the unit time Tpc of the contracted power Pc per unit time Tpc, as shown in FIG. The power amount Pct is calculated. Specifically, it is calculated by Pct=Pc/(60×Tc). That is, it is assumed that 3000 kWh in FIG. 4 is evenly divided and 50 kWh can be consumed per minute which is the control unit time Tc. This is the ideal power usage line L100 in FIG. Although the Tc value is exemplified as 1 minute, it may be 0.5 minutes, 2 minutes, or the like.

In step S102 of FIG. 2, the charging controller 50, as shown in FIG. 3, the integrated electric energy Pkt per control unit time by the electric energy measuring device 22 and the total per control unit time to the plurality of chargers 30 and 31. From the charging power amount Pjt, the power amount Pot per control unit time to the devices 40 other than the plurality of chargers is calculated. Specifically, it is calculated by Pot=Pkt-Pjt. The Pjt value is the total amount of power (total amount of charge power) to the plurality of chargers 30 and 31.

In step S103, the charge controller 50 allocates the allocated power amount Pct per control unit time and the power amount Pot per control unit time to the devices 40 other than the plurality of chargers from the control unit time per control unit time, as shown in FIG. The total chargeable electric energy Pjat is calculated. Specifically, it is calculated by Pjat=Pct-Pot.

In step S104 of FIG. 2, the charging controller 50, based on the total rechargeable power amount Pjat per control unit time, supplies a plurality of charging power instruction values to the chargers 30 and 31 from the present time to a plurality of control unit times. The charging power instruction value for the chargers 30 and 31 is determined. That is, the total rechargeable power amount before the control unit time Tc is set as the total rechargeable power amount for the control unit time Tc.

The initial value of the total chargeable power amount Pjat per control unit time is a fixed value.
In the comparative example shown in FIG. 4, when a fixed charge allocation amount is provided and the fixed charge amount has a fixed limiter function, the contracted power is not exceeded and the power supplied for charging is small over time. .. On the other hand, as shown in FIG. 4, in the first embodiment, it is possible to increase the electric power used for charging with time while preventing the contract electric power from being exceeded.

Conventionally, in order to prevent the contract power from being exceeded by controlling the electric power of a charger that charges an electric vehicle, it is necessary to establish a specific calculation method of a charging power instruction value. In addition, as shown in FIG. 8, the integrated power measured by the watt-hour meter 20 is the total of the power used by the device 40 other than the charger and the power used by the chargers 30, 31. Since the amount of electric power used by the charger is included in the above, it is necessary to grasp the available electric power. In the present embodiment, the Pjat value can be calculated even if the charger power amount is also included in the integrated power amount, and thus the available power to be charged can be grasped.

In step S105 of FIG. 2, the charging controller 50 outputs the charging power instruction value to the plurality of chargers 30 and 31. According to this instruction, each of the chargers 30 and 31 charges the vehicle equipped with the storage battery for, for example, Pjat/2 minutes per unit. That is, charging is performed within the range of the charging power instruction value.

According to the first embodiment, the following effects can be obtained.
(1) As the configuration of the power supply system 10, a power amount measuring device 22 as a power amount acquisition unit that acquires the amount of power supplied from the power system, and a vehicle 60 connected to the power system and equipped with storage batteries 61, 71, It has a plurality of chargers 30 and 31 for charging 70 and a device 40 other than the plurality of chargers connected to the power system. It has a charge controller 50 that controls charging power for the plurality of chargers 30 and 31. The charge controller 50 calculates the allocated power amount Pct (=Pc/60×Tc) per control unit time from the control unit time Tc that divides the unit time Tpc for the contract power Pc per unit time Tpc. The charging controller 50 performs a plurality of chargings based on an integrated power amount Pkt per control unit time by the power amount measuring device 22 as a power amount acquisition unit and a total charging power amount Pjt per control unit time to the plurality of chargers 30 and 31. A power amount Pot (=Pkt-Pjt) per control unit time to the devices 40 other than the appliances is calculated. The charging controller 50 calculates the total chargeable power amount Pjat (=Pct-Pot) per control unit time from the assigned power amount Pct per control unit time and the power amount Pot per control unit time to the devices 40 other than the plurality of chargers. ) Is calculated. Then, the charge controller 50 determines a charge power instruction value for the plurality of chargers 30 and 31 in the control unit time from the present time, based on the total chargeable power amount Pjat. Therefore, it is possible to calculate the charging power instruction value in a range that does not exceed the contracted power.

(Second embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.
In the second embodiment, the following functions are added as compared with the first embodiment.

In the present embodiment, as shown in FIG. 6, the difference between the instructed total charging power amount and the actually used total charging power amount is set as the error power amount Pgt, and the error power amount Pgt at the next Tc (for example, 1 minute). Taking into account (adding), the total charging electric energy is indicated. By effectively using this error power amount, that is, the surplus power, in the second embodiment, it is possible to approach the ideal power usage line L100 as shown in FIG.

Instead of FIG. 1, the process of FIG. 5 is executed. 5, the processing of steps S100, S101, S102, and S103 is the same as the processing of steps S100, S101, S102, and S103 of FIG. In this embodiment, if there is an error power amount Pgt (see FIG. 7), it is added (added) at the time of calculating the next total chargeable power amount.

As shown in FIG. 5, in step S200, the charge controller 50 determines the error power per control unit time from the allocated power amount Pct per control unit time and the integrated power amount Pkt per control unit time as shown in FIG. Calculate the amount Pgt. Specifically, it is calculated by Pgt=Pct-Pkt. Then, in step S201 of FIG. 5, the charge controller 50 adds the error power amount Pgt when calculating the total chargeable power amount Pjat per control unit time. That is, when there is the error power amount Pgt, it is added when the next total chargeable power amount is calculated.

Therefore, as shown in FIG. 6, the total rechargeable power amount Pjagt obtained by adding the error power amounts is equal to the sum of the allocated power amount Pct per control unit time and the error power amount Pgt per control unit time. It is a value obtained by subtracting the electric energy Pot per control unit time to the devices 40 other than the charger (Pjagt=Pct+Pgt-Poc).

Similarly, the error power amount Pgt is added as shown in FIG. 7. Then, the charging controller 50 determines in step S202 of FIG. 5 whether or not the unit time Tpc for the contracted power per unit time has elapsed. The charging controller 50 resets the error power amount Pgt added in step S203 when the unit time Tpc of the contract power per unit time has elapsed. At this time, the charge controller 50 sets a predetermined set value (fixed value) as the total rechargeable power amount Pjat for the first time after the reset or the total rechargeable power amount immediately before the reset.

In step S104 of FIG. 5, the charge controller 50 starts the control unit time from the present time to give the charge power instruction value to each of the chargers 30 and 31 based on the total chargeable power amount Pjat (Pjagt) per control unit time. The charging power instruction value for the plurality of chargers 30 and 31 is determined. In step S105 of FIG. 5, the charging controller 50 outputs the charging power instruction value to the plurality of chargers 30 and 31. According to this instruction, the plurality of chargers 30 and 31 charge the vehicles 60 and 70 equipped with the storage batteries 61 and 71. That is, charging is performed within the range of the charging power instruction value.

As a result, as shown in FIG. 4, in the first embodiment, the electric power supplied for charging with time is kept from exceeding the contracted electric power, and the electric power used line L100 is likely to be different from the ideal electric power use line L100. In the embodiment, by determining the total rechargeable power amount Pjat(Pjagt) in consideration of the error power amount Pgt, it is possible to increase the power supplied for charging with time while preventing the contract power from being exceeded.

According to the second embodiment, the following effect can be obtained in addition to the effect (1) described above.
(2) The charging controller 50 calculates the error power amount Pgt (=Pct-Pkt) per control unit time from the allocated power amount Pct per control unit time and the integrated power amount Pkt per control unit time, and can perform full charging. The error power amount Pgt is added when the power amount Pjat is calculated, and the error power amount added when the unit time Tpc of the contract power Pc per unit time Tpc has elapsed is reset. Therefore, it is possible to calculate the charging power instruction value in a range that does not exceed the contracted power so as to be closer to the contracted power.

(3) The charge controller 50 sets a predetermined set value as the total chargeable power amount Pjat for the first time after reset or the total chargeable power amount immediately before reset, which is practical.

The embodiment is not limited to the above, and may be embodied as follows, for example.
The electric energy of the electric power system was acquired from the electric energy meter by using the electric energy measuring device 22 as the electric energy acquisition unit that acquires the amount of electric power supplied from the electric power system. However, the present invention is not limited to this. The amount of electric power may be acquired by calculating the acquired instantaneous electric power.

○ It suffices if there are multiple chargers, regardless of the number.
The vehicle equipped with the storage battery may be an electric industrial vehicle other than an electric forklift truck, an electric vehicle (passenger vehicle), etc. other than the industrial vehicle.

10... Power supply system, 22... Electric energy measuring device, 30, 31... Charger, 40... Equipment other than a plurality of chargers, 50... Charge controller, 60... Vehicle, 61... Storage battery, 70... Vehicle, 71... Storage battery, Pc... Contract power per unit time, Pct... Allocated power amount per control unit time, Pjt... Control of multiple chargers Total charging power amount per unit time, Pot... Control of devices other than multiple chargers Electric energy per unit time, Pjat... Total chargeable electric energy per control unit time, Pgt... Error electric energy per control unit time, Pk... Integrated electric energy per control unit time, Tc... Control unit time, Tpc... Unit time.

Claims (3)

A power amount acquisition unit that acquires the amount of power supplied from the power grid,
A plurality of chargers connected to the power system for charging a vehicle equipped with a storage battery,
Equipment other than the plurality of chargers connected to the power system,
A power supply system having
A charging controller for controlling charging power for the plurality of chargers;
The charge controller is
The allocated power amount per control unit time is calculated from the control unit time that divides the unit time for the contract power per unit time, and the integrated power amount per control unit time by the power amount acquisition unit and the plurality of charges. Calculating a power amount per control unit time to devices other than a plurality of chargers from the total charging power amount per control unit time to the charger, and further, the allotted power amount per control unit time and the plurality of chargers Other than the device to calculate the total chargeable power amount per control unit time from the power amount per control unit time, based on the total chargeable power amount, from the present time to the plurality of chargers in the control unit time A power supply system characterized by determining a charging power instruction value. The charge controller is
The error power amount per control unit time is calculated from the allocated power amount per control unit time and the integrated power amount per control unit time, and the error power amount is added when the total chargeable power amount is calculated, The power supply system according to claim 1, wherein the added error power amount is reset when the unit time of the contract power per unit time has elapsed. The charge controller is
The power supply system according to claim 2, wherein a preset value or a total chargeable power amount immediately before resetting is set as the total chargeable power amount for the first time after the reset.