JP2022173746A - Power source device - Google Patents

Abstract

To inhibit a back flow of power inputted from a power storage device, to an AC power source.SOLUTION: A power source device 10 includes: an AC/DC converter 20 that converts AC power Pac inputted from an AC power source 110 to DC power; a load DC/DC converter 30 that is connected to the AC/DC converter 20 and outputs output power P1; a power storage DC/DC converter 50 that is connected in parallel with the load DC/DC converter 30 and converts stored power P2; and a control circuit 60 that supplies power to a target power storage device 120 by using at least one of the AC power source 110 and a power storage device 130 by controlling the converters 20, 30, 50. In this configuration, the control circuit 60 controls the converters 20, 30, 50 so that the stored power P2 becomes smaller than the output power P1 flowing from the load DC/DC converter 30 to the target power storage device 120.SELECTED DRAWING: Figure 1

Description

The present invention relates to power supply devices.

2. Description of the Related Art Conventionally, there is known a power supply device that converts power input from an AC power supply and a power storage device and outputs the power to a load (for example, Patent Document 1). The power supply device described in Patent Document 1 includes an AC/DC converter that converts AC power input from an AC power supply into DC power, and a load DC/DC converter that converts the DC power and outputs the converted DC power to a load. .

JP 2019-022255 A

In such a power supply device, when the power input from the power storage device is greater than or equal to the power output to the load, the power input from the power storage device may flow backward to the AC power supply.

A power supply device that solves the above problems includes an AC/DC converter that converts AC power input from an AC power source into DC power, and is connected to the AC/DC converter and outputs DC power to a load. a load DC/DC converter, a power storage DC/DC converter that is connected in parallel to the load DC/DC converter and converts stored power input from a power storage device, and controls each of the converters. a control circuit for supplying power to the load using at least one of the AC power supply and the power storage device, the control circuit configured to transfer the stored power from the load DC/DC converter to the Each said converter is controlled so that it is less than the output power to the load.

According to such a configuration, it is possible to suppress reverse flow of power from the power storage device to the AC power supply when the stored power input from the power storage device is equal to or greater than the output power.
In the power supply device, an intermediate capacitor is provided between the AC/DC converter and the load DC/DC converter and connected to each converter, and the control circuit controls the required output power of the load. a derivation unit for deriving a target output power, which is a target value of the output power, and a target stored power, which is a target value of the stored power, based on derived parameters including a limit changing unit that changes the target stored power to be equal to or less than the limited stored power when the target stored power is greater than the limited stored power obtained by subtracting the buffer power, and the intermediate voltage, which is the voltage of the intermediate capacitor, becomes the target intermediate voltage. and control the load DC/DC converter and the storage DC/DC converter so that the output power and the stored power become the target output power and the target stored power. It can be anything.

According to such a configuration, if the AC power is smaller than the buffer power, the operation of the AC/DC converter becomes unstable.
Therefore, according to such a configuration, when the target stored power is larger than the limit stored power, the target stored power is changed to the limit stored power or less. This keeps the AC power above the buffer power. Therefore, it is possible to suppress the operation of the AC/DC converter from becoming unstable.

In the above power supply device, the control circuit converts the target stored power derived by the deriving unit to It may be provided with a power storage changing unit that changes the value to be equal to or less than the upper limit stored power.

According to such a configuration, when the stored electric power becomes larger than the upper limit stored electric power, there is a possibility that the load on the electric storage device or the DC/DC converter for electric storage increases, for example.
Therefore, according to such a configuration, when the target stored power is changed by the stored power changing unit, the stored power becomes equal to or less than the upper limit stored power. As a result, it is possible to prevent an excessive load from being applied to the power storage device or the power storage DC/DC converter.

In the above-described power supply device, when a value obtained by adding an upper limit AC power, which is an upper limit of the AC power, and the target stored power set to be equal to or lower than the upper limit stored power, is defined as the limit output power, the control circuit an AC output changing unit that changes the target output power derived by the deriving unit to a value equal to or less than the limit output power when the target output power derived by the deriving unit is greater than the limit output power. There may be.

According to such a configuration, when the target output power is larger than the limited output power obtained by adding the target stored power and the upper limit AC power, the AC power may exceed the upper limit AC power. In this case, in order to protect the AC power supply from excessive output of AC power, there is concern that the supply of AC power may be interrupted or an excessive burden may be imposed on the power supply device.

Therefore, according to such a configuration, the control circuit changes the target output power to a value equal to or less than the limit output power when the target output power is larger than the limit output power. As a result, the output power output to the load becomes equal to or less than the limit output power. Along with this, the value obtained by subtracting the target stored power, which is equal to or less than the upper limit stored power, from the target output power becomes equal to or less than the upper limit AC power. Therefore, the AC/DC converter operates to output AC power equal to or lower than the upper limit AC power to the load DC/DC converter. Therefore, the above inconvenience can be suppressed.

In the above power supply device, the control circuit reduces the target output power derived by the deriving unit to It may be provided with an output changer for changing to a value equal to or less than the upper limit output power.

According to such a configuration, if the output power becomes larger than the upper limit output power, there is a risk that an excessive load will be applied to the load DC/DC converter, for example. Therefore, according to such a configuration, when the target output power is changed by the output changer, the output power becomes equal to or less than the upper limit output power. As a result, the operation of the load DC/DC converter can be stabilized.

ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the electric power input from an electrical storage apparatus flows back to AC power supply.

The figure which shows the outline of a power supply device and a power supply system. 4 is a sequence diagram for explaining power supply processing; FIG.

An embodiment of a power supply device and a power supply system including the power supply device will be described below.
As shown in FIG. 1 , power supply system 100 includes AC power supply 110 , target power storage device 120 as a load to which DC power is supplied, power storage device 130 , and power supply device 10 .

AC power supply 110 is a power source that outputs AC power Pac. Any AC power source can be used as the AC power source 110, and for example, it is a three-phase AC power source such as a system power source. The AC power Pac that can be supplied by the AC power supply 110 fluctuates according to, for example, the content of the contract with the power company, the power usage status of other power systems, and the like.

The target power storage device 120 of the present embodiment is rechargeable, and an example is a secondary battery. A secondary battery is, for example, a lithium ion storage battery or a lead storage battery. The target power storage device 120 may be, for example, one mounted on a vehicle.

The target power storage device 120 may be provided with the target BMS 121 . The target BMS 121 is a battery management system ( BMS: Battery Management System). Required output power P1r of target power storage device 120 is power required to charge target power storage device 120 . The allowable input power P1a is the upper limit of the power that can be input to the target power storage device 120. For example, it may be a fixed value that is predetermined based on the specifications of the target power storage device 120, or it may be a value depending on the SOC of the target power storage device 120. It may be a variable value that changes with time. Output voltage V1 is the voltage of target power storage device 120 .

The power storage device 130 is a power source capable of outputting DC power, and is, for example, a secondary battery. The power storage device 130 includes a power storage BMS 131 . The power storage BMS 131 monitors the outputtable power P2a of the power storage device 130, the power storage voltage V2, the SOC, and the SOH. The outputtable power P2a of the power storage device 130 is the upper limit of the power that the power storage device 130 can output. Possible output power P2a may be, for example, a fixed value predetermined based on the specifications of power storage device 130, or may be a variable value that changes according to the SOC of power storage device 130. FIG. The storage voltage V2 is the voltage of the storage device 130 .

Power supply device 10 converts power input from AC power supply 110 and power storage device 130 and outputs the converted power toward target power storage device 120 . Power supply device 10 is connected to AC power supply 110, target power storage device 120, and power storage device 130, respectively. The power supply device 10 includes an AC/DC converter 20 , a load DC/DC converter 30 , an intermediate capacitor 40 , an intermediate voltage sensor 41 , a storage DC/DC converter 50 , and a control circuit 60 .

AC/DC converter 20 is configured to be connectable to AC power supply 110 . AC/DC converter 20 converts AC power Pac from AC power supply 110 into DC power and outputs the DC power. For convenience of explanation, the DC power output from the AC power supply 110 will be referred to as first converted power Px in the following description. Although the AC/DC converter 20 may take any specific form, for example, it is a DAB (Dual Active Bridge) type AC/DC converter. The DAB AC/DC converter adjusts the voltage output from the AC/DC converter 20 by controlling the duty ratio and the phase difference between the voltage input to the primary circuit and the voltage output from the secondary circuit. You can control it.

Load DC/DC converter 30 is configured to be connectable to target power storage device 120 . The load DC/DC converter 30 is connected to the AC/DC converter 20 . Load DC/DC converter 30 converts input DC power and outputs the DC power toward target power storage device 120 . For convenience of description, in the following description, the DC power output from load DC/DC converter 30 toward target power storage device 120 is referred to as output power P1. It can also be said that output power P1 is power directed from load DC/DC converter 30 to target power storage device 120 . At this time, output current I1 proportional to output power P1 flows between load DC/DC converter 30 and target power storage device 120 .

The load DC/DC converter 30 of this embodiment is a chopper circuit. Note that the load DC/DC converter 30 may have any specific form, and may be, for example, a SEPIC converter or an LLC converter.

Intermediate capacitor 40 is provided between AC/DC converter 20 and load DC/DC converter 30 . AC/DC converter 20 can charge intermediate capacitor 40 by outputting first converted power Px, which is DC power.

Intermediate voltage sensor 41 is a voltage sensor that measures intermediate voltage Vm, which is the voltage of intermediate capacitor 40 .
Power storage DC/DC converter 50 is configured to be connectable to power storage device 130 . The storage DC/DC converter 50 is connected in parallel with the load DC/DC converter 30 . Also, the storage DC/DC converter 50 is connected to the intermediate capacitor 40 . An intermediate capacitor 40 is therefore connected to each converter 20 , 30 , 50 .

Power storage DC/DC converter 50 can step-down convert first converted power Px output from AC/DC converter 20 and output the converted power to power storage device 130 . Thereby, the power storage DC/DC converter 50 can charge the power storage device 130 using the AC power Pac (specifically, the first converted power Px) of the AC power supply 110 . In addition, power storage DC/DC converter 50 performs step-up conversion of stored power P2 input from power storage device 130, and outputs it as second converted power Py toward load DC/DC converter 30. FIG. As a result, the load DC/DC converter 30 receives the total power Px+Py obtained by adding the first converted power Px and the second converted power Py. At this time, a storage current I2 proportional to the storage power P2 flows between the power storage device 130 and the DC/DC converter 50 for storage.

Power storage DC/DC converter 50 operates by operating a switching element provided in power storage DC/DC converter 50 . Although the DC/DC converter 50 for power storage may take any specific form, it is, for example, a chopper circuit like the DC/DC converter 30 for load.

Control circuit 60 controls each converter 20 , 30 , 50 . A specific hardware configuration of the control circuit 60 is arbitrary. For example, the control circuit 60 may be configured to have a dedicated hardware circuit for performing switching control, or may include a memory storing a control program for performing switching control and necessary information, and switching control based on the control program. A configuration having a CPU that performs

Control circuit 60 acquires derived parameters for controlling each converter 20 , 30 , 50 . Control circuit 60 acquires required output power P1r, input power P1a, and output voltage V1 of target power storage device 120 from target BMS 121 . Specifically, the control circuit 60 is communicably connected to the target BMS 121, and acquires the required output power P1r, the available input power P1a, and the output voltage V1 by communicating with the target BMS 121. Although any communication method can be used, for example, communication according to vehicle communication protocols such as CAN: Controller Area Network and LIN: Local Interconnect Network can be mentioned. Similarly, the control circuit 60 acquires the outputtable power P2a of the power storage device 130 and the power storage voltage V2 from the power storage BMS 131 .

Further, the control circuit 60 outputs the AC power Pac and the first converted power Px from the AC/DC converter 20, the output power P1 from the load DC/DC converter 30, the stored power P2 from the power storage DC/DC converter 50, and the first converted power Px. 2 conversion power Py is acquired respectively. For example, the control circuit 60 acquires these derived parameters from current sensors and voltage sensors provided on the input side and the output side of each converter 20, 30, 50, respectively.

Control circuit 60 performs a power supply process of supplying power to target power storage device 120 using at least one of AC power supply 110 and power storage device 130 by controlling each converter 20 , 30 , 50 . In the power supply process, control circuit 60 controls intermediate voltage Vm by controlling AC/DC converter 20, controls output power P1 by controlling load DC/DC converter 30, and controls power storage DC/DC converter 50. The control controls the second converted power Py. Note that the second converted power Py is a value that is reduced from the stored power P2 according to the power conversion efficiency of the DC/DC converter 50 for power storage. Therefore, the control circuit 60 can control the stored power P2 by controlling the second converted power Py. In other words, it can be said that the control circuit 60 controls the stored power P2 by controlling the storage DC/DC converter 50 .

Here, when the output power P1 becomes larger than the stored power P2, the load DC/DC converter 30 charges the intermediate capacitor 40 in order to compensate for the difference P1-P2 between the output power P1 and the stored power P2. withdraw the charge. This causes a voltage drop of the intermediate voltage Vm. At this time, control circuit 60 controls AC/DC converter 20 to maintain intermediate voltage Vm. As a result, the difference P1-P2 between the output power P1 and the stored power P2 is output from the AC/DC converter 20 as the first converted power Px. Along with this, the AC power Pac increases. Therefore, AC/DC converter 20 maintains intermediate voltage Vm to output first converted power Px corresponding to difference P1−P2 between output power P1 and stored power P2 toward load DC/DC converter 30. .

<About power supply processing>
Next, an example of power supply processing performed by the control circuit 60 will be described. The power supply process in this embodiment is a process of supplying power to the target power storage device 120 . Power supply to the target power storage device 120 is charging the target power storage device 120, for example. The power supply process may be performed at any timing. For example, the power supply process may be performed at regular intervals or triggered by a predetermined input to the control circuit 60 . The predetermined input is, for example, a command to start charging the target power storage device 120 or a command to end charging to the target power storage device 120 .

For convenience of explanation, power loss due to each converter 20, 30, 50 is ignored in the following explanation. Therefore, the first converted power Px is treated as the AC power Pac, the second converted power Py is treated as the stored power P2, and the total power Px+Py is treated as the output power P1. That is, the power storage DC/DC converter 50 is treated as controlling the stored power P2.

As shown in FIG. 2, in step S1, the control circuit 60 acquires derived parameters used for power supply processing. The derived parameters of this embodiment include the required output power P1r, the possible input power P1a, the possible output power P2a, the output voltage V1, and the storage voltage V2.

Next, control circuit 60 proceeds to step S2 to derive target output power P1t, target stored power P2t, and target intermediate voltage Vmt based on derived parameters including required output power P1r. Specifically, control circuit 60 derives required output power P1r as target output power P1t, and derives target stored power P2t based on required output power P1r.

The target stored power P2t is arbitrary as long as it is the stored power P2 required for the output power P1 to become the target output power P1t, but may be set based on the power conversion efficiency, for example. For example, the target stored power P2t may be set corresponding to the required output power P1r so that the power conversion efficiency of the power supply device 10 is maximized.

The target intermediate voltage Vmt is the target value of the intermediate voltage Vm. The value of target intermediate voltage Vmt may be, for example, a value derived from output voltage V1 and storage voltage V2, or a predetermined value. Although the value of the target intermediate voltage Vmt is arbitrary, it is preferably larger than both the values of the output voltage V1 and the storage voltage V2. Thereby, for example, unintended power transmission from the target power storage device 120 to the power storage device 130 can be suppressed. In this embodiment, the control circuit 60 that executes the process of step S2 corresponds to the derivation unit.

Next, the control circuit 60 proceeds to step S3 and determines whether or not the target output power P1t is equal to or less than the upper limit output power P1max. The upper limit output power P1max is the upper limit of the output power P1. The upper limit output power P1max is, for example, the smaller value of the allowable input power P1a and the allowable output power P1b. The power supply output allowable power P1b is a parameter that is appropriately set based on the specifications of the power supply 10, for example. The power supply output allowable power P1b is, for example, the maximum value of power that can be output by the load DC/DC converter 30 or a value obtained by subtracting a predetermined value from the maximum value.

If the determination result in step S3 is affirmative, the control circuit 60 proceeds to step S5. On the other hand, if the determination result in step S3 is negative, the control circuit 60 proceeds to step S4.
In step S4, the control circuit 60 changes the target output power P1t to the upper limit output power P1max. As a result, it is possible to prevent the power supply device 10 and the target power storage device 120 from being overloaded. Note that the control circuit 60 may change the target output power P1t to a value smaller than the upper limit output power P1max in step S4. That is, the control circuit 60 may change the target output power P1t to a value equal to or lower than the upper limit output power P1max. In this embodiment, the control circuit 60 that executes the processing of step S4 corresponds to the output changer. After executing the process of step S4, the control circuit 60 proceeds to step S5.

In step S5, the control circuit 60 determines whether or not the target stored power P2t is equal to or less than the upper limit stored power P2max. The upper limit stored power P2max is the upper limit of the stored power P2. The upper limit stored power P2max is, for example, the smaller value of the possible output power P2a and the storage input allowable power P2b. The storage input allowable power P2b is a parameter that is appropriately set based on the specifications of the power supply device 10, for example. The storage input allowable power P2b is, for example, the maximum value of power that can be converted by the storage DC/DC converter 50 or a value obtained by subtracting a predetermined value from the maximum value.

If the determination result in step S5 is affirmative, the control circuit 60 proceeds to step S7. On the other hand, if the determination result in step S5 is negative, the control circuit 60 proceeds to step S6.
In step S6, the control circuit 60 changes the value of the target stored power P2t to the value of the upper limit stored power P2max. As a result, it is possible to prevent the power supply device 10 and the power storage device 130 from being overloaded. Note that the control circuit 60 may change the target stored power P2t to a value equal to or lower than the upper limit stored power P2max in step S6. In the present embodiment, the control circuit 60 that executes the process of step S6 corresponds to the power storage changing unit. After executing the process of step S6, the control circuit 60 proceeds to step S7.

In step S7, the control circuit 60 determines whether or not the target stored power P2t is equal to or less than the limit stored power P1t-Pbuff. The limit stored power P1t-Pbuff is a value obtained by subtracting the buffer power Pbuff from the target output power P1t. The buffer power Pbuff is, for example, the lower limit value of the AC power Pac (in other words, the first conversion power Px) required for the AC/DC converter 20 to operate stably. Note that the buffer power Pbuff is arbitrary as long as it is greater than zero. If the determination result in step S7 is affirmative, the control circuit 60 proceeds to step S9. On the other hand, if the determination result in step S7 is negative, the control circuit 60 proceeds to step S8.

In step S8, the control circuit 60 changes the target stored power P2t to the limit stored power P1t-Pbuff. When the process of step S8 is performed, the stored power P2 becomes equal to or less than the limit stored power P1t-Pbuff, which is lower than the output power P1. As described above, the difference P1−P2 between the output power P1 and the stored power P2 is input from the AC power supply 110 to the AC/DC converter 20 . Therefore, the AC power Pac input to the AC/DC converter 20 becomes equal to or greater than the buffer power Pbuff by performing the process of step S8.

Note that the control circuit 60 may change the target stored power P2t to a value smaller than the limit stored power P1t-Pbuff in step S8. That is, the control circuit 60 may change the target stored power P2t to a value equal to or less than the limit stored power P1t-Pb. In the present embodiment, the control circuit 60 that executes the process of step S8 corresponds to the limit changing section. After executing the process of step S8, the control circuit 60 proceeds to step S9.

At step S9, the control circuit 60 derives the limit output power Ptotal. The limit output power Ptotal is a value obtained by adding the upper limit AC power Pacmax and the target stored power P2t set to be equal to or lower than the upper limit stored power P2max through steps S5 and S6. The upper limit AC power Pacmax is the upper limit of the AC power Pac. The upper limit AC power Pacmax may be, for example, a value that is appropriately set according to the content of a contract with an electric power company or the power usage status of another electric power system, or the power supply device 10 (in other words, AC/DC converter 20) It may be a value appropriately set based on the specifications, or may be the smaller one of the above two values. The upper limit AC power Pacmax is arbitrary as long as it is greater than 0, but is preferably greater than the buffer power Pbuff.

Next, the control circuit 60 proceeds to step S10 and determines whether or not the target output power P1t is equal to or less than the limit output power Ptotal. If the determination result in step S10 is affirmative, the control circuit 60 proceeds to step S12. On the other hand, if the determination result in step S10 is negative, the control circuit 60 proceeds to step S11.

In step S11, the control circuit 60 changes the target output power P1t to the limit output power Ptotal. This change reduces the target output power P1t, but does not change the target stored power P2t. Therefore, it can be said that the control circuit 60 limits the output power P1 by the process of step S11 so that the AC power Pac becomes the upper limit AC power Pacmax.

Note that the control circuit 60 may change the target output power P1t to a value smaller than the limit output power Ptotal in step S11. That is, the control circuit 60 may change the target output power P1t to a value equal to or less than the limit output power Ptotal. In this embodiment, the control circuit 60 that executes the process of step S11 corresponds to the AC output changer. After executing the process of step S11, the control circuit 60 proceeds to step S12.

In step S12, the control circuit 60 sets the target output current I1t and the target stored current I2t based on the target output power P1t and the target stored power P2t. The control circuit 60 sets a value obtained by dividing the target output power P1t by the output voltage V1 as the target output current I1t, and sets a value obtained by dividing the target stored power P2t by the stored voltage V2 as the target stored current I2t.

Next, the control circuit 60 proceeds to step S13, and controls the converters 20, 30, 50 so that the intermediate voltage Vm, the output current I1, and the storage current I2 become the respective target values Vmt, I1t, I2t. . Specifically, control circuit 60 controls AC/DC converter 20 so that intermediate voltage Vm becomes target intermediate voltage Vmt. Further, the control circuit 60 controls the load DC/DC converter 30 so that the output current I1 becomes the target output current I1t. Furthermore, the control circuit 60 controls the power storage DC/DC converter 50 so that the power storage current I2 becomes the target power storage current I2t. Thereby, the control circuit 60 controls the load DC/DC converter 30 and the storage DC/DC converter 50 so that the output power P1 and the stored power P2 become the target output power P1t and the target stored power P2t.

<Action>
Next, the operation of this embodiment will be described.
When the target stored power P2t is equal to or greater than the target output power P1t, the determination result of the control circuit 60 in step S7 is negative. Therefore, the control circuit 60 proceeds to step S8 to change the target stored power P2t to the limit stored power P1t-Pbuff, which is smaller than the target output power P1t. Then, the control circuit 60 controls each converter 20, 30, 50 based on the processing of steps S12 and S13. As a result, the output power P1 becomes the target output power P1t after the change, and the stored power P2 becomes the target stored power P2t. As described above, target output power P1t after change is smaller than target stored power P2t, so output power P1 is also smaller than stored power P2.

<effect>
According to this embodiment detailed above, the following effects are obtained.
(1) The power supply device 10 is connected to an AC/DC converter 20 that converts the AC power Pac input from the AC power supply 110 into first converted power Px that is DC power, and the AC/DC converter 20, A load DC/DC converter 30 that outputs output power P1, which is DC power, toward a target power storage device 120, and a load DC/DC converter 30 that is connected in parallel to the load DC/DC converter 30 and receives an input from the power storage device 130. Power is supplied to the target power storage device 120 using at least one of the AC power supply 110 and the power storage device 130 by controlling the power storage DC/DC converter 50 that converts the stored power P2 and the respective converters 20, 30, and 50. and a control circuit 60 for performing

In such a configuration, control circuit 60 controls converters 20 , 30 , 50 such that stored power P<b>2 is smaller than output power P<b>1 directed from load DC/DC converter 30 to target power storage device 120 .

According to such a configuration, it is possible to suppress reverse flow of the stored power P2 to the AC power supply 110 by making the stored power P2 input from the power storage device 130 equal to or higher than the output power P1.
(2) The power supply device 10 includes an intermediate capacitor 40 provided between the AC/DC converter 20 and the load DC/DC converter 30 and connected to each converter 20 , 30 , 50 .

In such a configuration, the control circuit 60 calculates the target output power P1t, which is the target value of the output power P1, and the target stored power P2, which is the target value of the stored power P2, based on derived parameters including the required output power P1r of the target power storage device 120. The process of step S2 for deriving the power P2t is executed. When the target stored power P2t is larger than the limit stored power P1t−Pbuff obtained by subtracting the buffer power Pbuff from the target output power P1t, the control circuit 60 changes the target stored power P2t to the limit stored power P1t−Pbuff or less (step S8). process.

In such a configuration, the control circuit 60 controls the AC/DC converter 20 so that the intermediate voltage Vm, which is the voltage of the intermediate capacitor 40, becomes the target intermediate voltage Vmt, and the output power P1 and the stored power P2 reach the target output power P1t. and the load DC/DC converter 30 and the storage DC/DC converter 50 are controlled so as to achieve the target stored power P2t.

If AC power Pac is smaller than buffer power Pbuff, the operation of AC/DC converter 20 becomes unstable.
Therefore, according to such a configuration, when the target stored power P2t is larger than the limit stored power P1t-Pbuff, the target stored power P2t is changed to the limit stored power P1t-Pbuff or less. Thereby, AC/DC converter 20 operates to output at least buffer power Pbuff to AC/DC converter 20 . Therefore, the AC power Pac is kept at or above the buffer power Pbuff. Therefore, it is possible to suppress the operation of the AC/DC converter 20 from becoming unstable.

(3) When the target stored power P2t derived by the processing in step S2 is greater than the upper limit stored power P2max, which is the upper limit of the stored power P2, the control circuit 60 sets the target stored power P2t to a value equal to or lower than the upper limit stored power P2max. The process of step S6 for changing to a value is executed.

According to such a configuration, if the stored power P2 becomes larger than the upper limit stored power P2max, there is a risk that the load on the power storage device 130 or the power storage DC/DC converter 50 will increase, for example.

Therefore, according to such a configuration, when the control circuit 60 executes the process of step S6 to change the target stored power P2t, the stored power P2 becomes equal to or less than the upper limit stored power P2max. As a result, it is possible to prevent an excessive burden from being applied to the power storage device 130 or the power storage DC/DC converter 50 .

(4) If the value obtained by adding the upper limit AC power Pacmax, which is the upper limit of the AC power Pac, and the target stored power P2t set to be equal to or lower than the upper limit stored power P2max through steps S5 and S6, is defined as the limit output power Ptotal, If the target output power P1t derived in step S2 is greater than the limit output power Ptotal, the control circuit 60 executes the process of step S11 to change the target output power P1t to a value equal to or less than the limit output power Ptotal.

According to such a configuration, when the target output power P1t is larger than the limit output power Ptotal, the AC power Pac may exceed the upper limit AC power Pacmax. In this case, in order to protect the AC power supply 110 from excessive output of the AC power Pac, there is concern that the supply of the AC power Pac may be interrupted or an excessive burden may be applied to the power supply device 10 .

Therefore, according to such a configuration, when the target output power P1t is greater than the limit output power Ptotal, the control circuit 60 executes the process of step S11 to reduce the target output power P1t to a value equal to or less than the limit output power Ptotal. change. As a result, the output power P1 output to the target power storage device 120 becomes equal to or less than the limit output power Ptotal. Accordingly, the value obtained by subtracting the target stored power P2t, which is equal to or less than the upper limit stored power P2max, from the target output power P1t becomes equal to or less than the upper limit AC power Pacmax. Therefore, AC/DC converter 20 operates to output AC power Pac equal to or lower than upper limit AC power Pacmax to load DC/DC converter 30 . Therefore, the above inconvenience can be suppressed.

(5) When the target output power P1t derived by the process of step S2 is greater than the upper limit output power P1max, which is the upper limit of the output power P1, the control circuit 60 sets the target output power P1t to the upper limit output power P1max or less. The process of step S4 for changing to a value is executed.

According to such a configuration, if the output power P1 becomes larger than the upper limit output power P1max, there is a risk that an excessive load will be applied to the load DC/DC converter 30, for example.
Therefore, according to such a configuration, when the target output power P1t is changed by the control circuit 60 executing the process of step S4, the output power P1 becomes equal to or less than the upper limit output power P1max. Thereby, the operation of the load DC/DC converter 30 can be stabilized.

<Modification>
Embodiments can be implemented with the following modifications. The embodiments and the following modified examples can be implemented in combination with each other within a technically consistent range.

○ The control sequence in the embodiment is merely an example, and is not limited to the embodiment. For example, the order of each step can be changed as appropriate.
(circle) in the process of step S11, the control circuit 60 may change the target stored power P2t to be smaller in accordance with the change of the target output power P1t. At this time, the target output power P1t and the target stored power P2t only need to satisfy the relationships described in steps S7 and S10.

(circle) the process of step S3 and step S4 does not need to be performed. Further, the processes of steps S5 and S6 may not be executed. The processes of steps S10 and S11 may not be executed. The point is that the processes of steps S7 and S8 should be executed.

○ When the power loss of each converter 20, 30, 50 is taken into consideration, the control mode of each converter 20, 30, 50 may be appropriately modified based on the correspondence between the input and output of each converter 20, 30, 50. good.

(circle) each converter 20,30,50 may be controlled based on the input of each converter 20,30,50, and may be controlled based on an output.
○ A plurality of load DC/DC converters 30 may be provided. The load DC/DC converters 30 are preferably connected in parallel with each other. At this time, for example, the total power output from each load DC/DC converter 30 may be handled as the output power P1. When a plurality of load DC/DC converters 30 are provided, the upper limit output power P1max may be set individually according to the power output from each load DC/DC converter 30 .

○ A plurality of power storage DC/DC converters 50 may be provided. The power storage DC/DC converters 50 are preferably connected in parallel with each other. At this time, for example, the total power input to each power storage DC/DC converter 50 may be handled as the stored power P2. When a plurality of power storage DC/DC converters 50 are provided, the upper limit power storage P2max may be set individually for each power input to each power storage DC/DC converter 50 .

(circle) the intermediate capacitor 40 and the intermediate voltage sensor 41 may not be provided.
O The target power storage device 120 may not be provided with the target BMS 121 . For example, instead of the target BMS 121, a sensor for grasping the required output power P1r and the output voltage V1 of the target power storage device 120 may be provided separately. At this time, the control circuit 60 may derive the target output current I1t using the required output power P1r and the output voltage V1 that can be obtained from the sensor.

O The load is not limited to the target power storage device 120, and any drive device capable of supplying DC power, such as a resistor or a DC motor, can be used. In this case, the output power P1 and the output voltage V1 are the power and voltage required to drive the driver.

DESCRIPTION OF SYMBOLS 10... Power supply device, 20... AC/DC converter, 30... DC/DC converter for load, 40... Intermediate capacitor, 50... DC/DC converter for electric power storage, 60... Control circuit, 110... AC power supply, 120... Target electric storage apparatus , 130 power storage device P1 output power P1max upper limit output power P1r required output power P1t target output power P1t−Pbuff limit stored power P2 stored power P2max upper limit stored power P2t Target stored power, Pbuff...Buffer power, Ptotal...Limited output power, Vm...Intermediate voltage, Vmt...Target intermediate voltage.

Claims (5)

an AC/DC converter that converts AC power input from an AC power supply into DC power;
a load DC/DC converter that is connected to the AC/DC converter and outputs DC power to a load;
a power storage DC/DC converter connected in parallel to the load DC/DC converter and converting stored power input from a power storage device;
a control circuit that supplies power to the load using at least one of the AC power supply and the power storage device by controlling each converter;
The power supply device, wherein the control circuit controls each of the converters so that the stored power is smaller than output power directed from the load DC/DC converter to the load. an intermediate capacitor provided between the AC/DC converter and the load DC/DC converter and connected to each converter;
The control circuit is
a deriving unit that derives a target output power, which is a target value of the output power, and a target stored power, which is a target value of the stored power, based on derived parameters including the required output power of the load;
a limit changing unit that changes the target stored power to the limit stored power or less when the target stored power is greater than the limit stored power obtained by subtracting the buffer power from the target output power;
The AC/DC converter is controlled such that the intermediate voltage, which is the voltage of the intermediate capacitor, becomes a target intermediate voltage, and the load is controlled so that the output power and the stored power become the target output power and the target stored power. 2. The power supply device according to claim 1, which controls a DC/DC converter for power storage and the DC/DC converter for power storage. When the target stored power derived by the derivation unit is greater than an upper limit stored power, which is an upper limit value of the stored power, the control circuit reduces the target stored power derived by the derivation unit to a value equal to or lower than the upper limit stored power. 3. The power supply device according to claim 2, comprising an electricity storage changing unit that changes the value. Assuming that the sum of the upper limit AC power, which is the upper limit of the AC power, and the target stored power, which is set to be equal to or lower than the upper limit stored power, is defined as the limit output power,
The control circuit changes the AC output power derived by the derivation unit to a value equal to or less than the limit output power when the target output power derived by the derivation unit is greater than the limit output power. 4. The power supply of claim 3, comprising a portion. When the target output power derived by the derivation unit is greater than an upper limit output power that is an upper limit value of the output power, the control circuit reduces the target output power derived by the derivation unit to a level equal to or lower than the upper limit output power. The power supply device according to any one of claims 2 to 4, comprising an output changer that changes the value.

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