Power conversion system, device, power conversion control method, and program

Abstract

To make it possible to efficiently charge a battery of one system using a simpler method.SOLUTION: A power conversion system comprises: a plurality of power converters that are arranged between a power generator and a battery of one system, where output sides of the plurality of power converters are connected mutually and are connected to the battery of the one system in a chargeable manner and power supplied from the power converters is converted by any of constant current charge control (called as CC charge control) and constant voltage charge control (called as CV charge control); and a common controller for supplying, to the respective converters, information on the number of systems of the plurality of power converters for making each of the plurality of power converters perform the CC charge control, and information showing a charged state of the battery for making the CV charge control be performed. The common controller calculates first information, information showing the charged state of the battery, using internal impedance information of the battery and voltage of the battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power conversion system, a device, a power conversion control method, and a program. [Background technology]

[0002] There is known a power conversion system in which a power converter arranged between a power generation device and a battery converts the power supplied from the power generation device and charges the battery in one system. As the power consumption of the load of the power conversion system increases, there is a demand for an increase in the battery capacity. Lithium ion batteries and the like are suitable for such applications. In battery charging control, for example, when the charge amount SOC (State Of Charge) is low, the battery is charged with a control to charge the battery at a constant current, that is, constant current charging control, and then, when the charge amount becomes high, the battery is charged with a control to adjust the voltage according to the battery voltage, that is, constant voltage charging control. In this way, it is desirable to switch the charging control method depending on the balance between the amount of power used and the amount of power generated by the power generation device. However, when the output sides of multiple power converters are connected in parallel to ensure the amount of power conversion required for a power conversion system, the output current may be biased toward a specific power converter due to variations in the output voltages of the power converters. Therefore, even if multiple power converters are connected in parallel, it is difficult to increase the power obtained from the multiple power converters. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 155442 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology in Patent Document 1 merely shows an example of constant current charging control and constant voltage charging control, and does not disclose any combination of multiple power converters. There has been a demand for a technology that can efficiently charge a single battery system using a simpler method.

[0005] Therefore, an object of the present invention is to provide a power conversion system, a device, a power conversion control method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] According to a first aspect of the invention, a power conversion system is provided which is arranged between a power generating device and a system of batteries, the output sides of a plurality of power converters are connected to each other and to the system of batteries in a chargeable manner, and which each converts the power supplied from the power generating device using either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), and a common controller which supplies each power converter with information on the number of systems of the plurality of power converters to cause each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery to perform CV charging control, and the common controller calculates first information, which is information indicating the charging state of the battery, using internal impedance information of the battery and the voltage of the battery.

[0007] According to a second aspect of the invention, there is provided an apparatus comprising a power generation device, a storage battery, and the power conversion system according to the first aspect.

[0008] According to a third aspect of the invention, there is provided a power conversion control method, the power converter being arranged between a power generating device and a system of batteries, the output sides of a plurality of power converters being connected to each other and to the system of batteries in a chargeable manner, and each of the power converters converts the power supplied from the power generating device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), the power conversion control method including: supplying information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery for performing CV charging control, and calculating first information, which is information indicating the charging state of the battery, using internal impedance information of the battery and a voltage of the battery.

[0009] According to a fourth aspect of the invention, a program is provided for causing a computer of a power conversion system including a plurality of power converters arranged between a power generating device and a system of batteries, the output sides of the plurality of power converters being connected to each other and to the system of batteries in a chargeable manner, to supply to each of the power converters, which respectively convert the power supplied from the power generating device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery for performing CV charging control, and calculating first information, which is information indicating the charging state of the battery, using internal impedance information of the battery and the voltage of the battery. Effect of the Invention

[0010] According to the present invention, it is possible to provide a power conversion system, device, power conversion control method, and program that are configured by combining multiple power converters and perform constant current charging control and constant voltage charging control in a simpler manner. [Brief description of the drawings]

[0011] [Figure 1]FIG. 1 is a diagram for explaining a power conversion system according to the present disclosure. [Diagram 2] 4 is a flowchart of a calculation process related to charging control by a common circuit according to the present disclosure. [Diagram 3] 4 is a flowchart of a calculation process related to charging control by a converter circuit according to the present disclosure. [Figure 4] FIG. 2 is a diagram for explaining charging control in a power supply control device according to the present disclosure. [Diagram 5] FIG. 1 is a diagram illustrating an example of an apparatus configuration according to the present disclosure. [Figure 6] 4 is a flowchart of charging control according to the present disclosure. [Figure 7] FIG. 1 is a schematic block diagram illustrating an example configuration of a computer according to the present disclosure. [Figure 8] 1 is a diagram illustrating a configuration example of a power conversion system according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A power conversion system according to an embodiment of the present invention will be described below with reference to the drawings. The following description is for explaining the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. In addition, each element of the following embodiment can be easily changed, added, or converted within the scope of the present invention.

[0013] (First embodiment) FIG. 1 is a diagram for explaining a power conversion system 1 according to the present disclosure. As shown in FIG. 1, a power conversion system 1 charges a battery in one system using power generated by a power generation device, and further supplies a portion of the power to a load of the power conversion system 1.

[0014] First, the configuration of a power conversion system 1 including a power supply control device 10 according to the present embodiment will be described in detail with reference to FIG.

[0015] The power conversion system 1 includes a power supply control device 10 and a battery 40 (BAT). The power supply control device 10 converts power from power generation devices such as solar cell arrays 21, 22, . . . , 2n, and supplies the converted power to a load 30 and a battery 40. For example, the power generation device is a power generation source for the power supply control device 10. The power generation device is composed of a single or multiple solar cell arrays (solar cell arrays 21, 22, ..., 2n) configured in a total of n stages (n: natural number). Each of the solar cell arrays 21, 22, ..., 2n is composed of multiple single solar cell cells connected in series and parallel. A pair of positive power output lines SAP HOT and negative power output lines SAP RTN are respectively associated and connected to the solar cell arrays 21, 22, ..., 2n. The positive and negative output terminals of the solar cell arrays 21, 22, ..., 2n are respectively connected to the converter circuit of the power supply control device 10 via a pair of positive power output lines SAP HOT and negative power output lines SAP RTN. In a wired state, the negative electrodes of the solar cell arrays 21, 22, ..., 2n are configured to have a common potential, and the positive electrodes are configured independently of each other. In the following description, when the solar cell arrays 21, 22, ..., 2n are described without distinction, they may be collectively referred to as the solar cell array 20.

[0016] As described above, the power supply control device 10 converts the power generated by the solar cell array 20 and supplies the converted power to the load 30 and the battery 40.

[0017] The load 30 is a load that consumes electric power obtained by generating electricity from the solar cell arrays 21, 22, . . . , 2n or electric power stored in the battery 40 to realize a desired function.

[0018] The battery 40 is a single-system power storage device configured by connecting multiple storage batteries (storage battery cells) in series. The battery 40 is divided into a battery body with ideal characteristics and an internal impedance 40r, and modeled as a circuit in which these are connected in series. The value of the internal impedance 40r (referred to as an internal impedance value r) is a value obtained by adding the sum of the impedance (resistance component) inside the storage battery cells to the impedance (resistance component) of wiring for connecting the storage batteries. The battery 40 includes a positive terminal 40P and a negative terminal 40N. The voltage generated between the positive terminal 40P and the negative terminal 40N is referred to as the terminal voltage of the battery 40. In the following description, the voltage BAT_V obtained by dividing the terminal voltage of the battery 40 may be used instead of the terminal voltage of the battery 40. The internal impedance value r is an example of internal impedance information.

[0019] Next, a configuration example of the power supply control device 10 will be described. The power supply control device 10 includes a converter circuit 110 and a common circuit 120 . The converter circuit 110 includes, for example, converter circuits 111, 112, ..., 11n. Each of the converter circuits 111, 112, ..., 11n is an example of a power conversion device. For example, the positive pole side of each of the converter circuits 111, 112, ..., 11n is connected to a positive pole side power output line SAP HOT corresponding to the converter circuit at its power supply side, and the load side is connected to a common positive pole side bus voltage line BUS HOT. As a result, the positive pole of each solar cell array is connected to the positive pole of the load 30 via the positive pole side power output line SAP HOT, the positive pole side of the converter circuit 110, and the positive pole side bus voltage line BUS HOT.

[0020] The negative pole side of each of the converter circuits 111, 112, ..., 11n is connected to a negative pole side power output line SAP RTN corresponding to the converter circuit. The load side is connected to a common negative pole side bus voltage line BUS RTN via the negative pole side power output line SAP RTN. Thus, the negative pole of each solar cell array is connected to the negative pole of the load 30 via the negative pole side power output line SAP RTN, the negative pole side of the converter circuit 110, and the negative pole side bus voltage line BUS RTN. The potential of the negative bus voltage line BUS RTN is set as the reference potential of the power supply control device 10. The potential of the positive bus voltage line BUS HOT relative to the reference potential of the power supply control device 10 varies depending on the power generation state of each solar cell array and the charging state of the battery 40, which will be described later. In the following description, when the converter circuits 111, 112, ..., 11n are described without distinction, they may be collectively referred to as converter circuits 110.

[0021] One system of battery 40 is disposed between the positive bus voltage line BUS HOT and the negative bus voltage line BUS RTN, and both poles of the battery 40 are connected to the positive bus voltage line BUS HOT and the negative bus voltage line BUS RTN. The power generation state (power generation amount) of the solar cell arrays 21, 22, ..., 2n and the load power required by the load 30 change depending on the situation. For example, the converter circuit 110 adjusts the conversion amount so as to reduce the influence of the power generation state (power generation amount) of each of the solar cell arrays 21, 22, ..., 2n. However, when the load power required by the load 30 becomes greater than the total generated power, i.e., the total output power, of the solar cell arrays 21, 22, ..., 2n, the voltage between the positive bus voltage line BUS HOT and the negative bus voltage line BUS RTN (the voltage of the bus voltage line) drops. When the voltage of the bus voltage line in this case drops to the voltage of the battery 40, power discharged from the battery 40 is supplied to the bus voltage line. As a result, the shortfall in the load power required by the load 30 is made up for by the power discharged from the battery 40. Furthermore, when the amount of power generated by each of the solar cell arrays 21, 22, ..., 2n further decreases and the output voltage of each converter circuit 110 becomes clearly lower than the voltage of the battery 40 (the voltage of the bus voltage line), the converter circuit 110 and the solar cell arrays 21, 22, ..., 2n are protected by the current backflow prevention element D1 from the reverse bias caused by the voltage of the bus voltage line.

[0022] A more specific example of the converter circuit 110 will be described. Each of the n-stage converter circuits 111, 112, ..., 11n has the same circuit configuration. In the following, the first-stage converter circuit 111 will be focused on and its internal circuit configuration will be described in detail.

[0023] The converter circuit 111 includes a chopper circuit 1111, a first resistor R1, a current backflow prevention element D1, a drive circuit 1115, an A / D converter 1116, an arithmetic processing unit 1117, a differential amplifier 1118A, an A / D converter 1118B, and a judgment processing unit 1119. A chopper circuit 1111, a first resistor R1, and a current backflow prevention element D1 are provided between the positive power output line SAP HOT and the positive bus voltage line BUS HOT of the solar cell array 21. Note that the pole connected to the negative power output line SAP RTN and the negative bus voltage line BUS RTN is simply called the negative pole.

[0024] The chopper circuit 1111 includes an input stage smoothing circuit, a switching circuit, and an output stage smoothing circuit. The input stage smoothing circuit includes an inductor L1 and a capacitor C1. The switching circuit includes semiconductor switching elements TR1 and TR2. The output stage smoothing circuit includes an inductor L2 and a capacitor C2. The semiconductor switching elements TR1 and TR2 are switching elements such as bipolar transistors, IGBTs, MOSFETs, and GaNFETs. The symbols shown in the figure are FETs as an example, but may be changed as appropriate without being limited to this. The semiconductor switching elements TR1 and TR2 may be provided with reverse-connected diodes as necessary. The capacitors C1 and C2 are examples of capacitive power storage elements. The inductors L1 and L2 are examples of inductive power storage elements. The semiconductor switching element TR1 is provided in the rear stage of the input stage smoothing circuit and cuts off the current flowing from the inductor L1 and the capacitor C1 of the input stage smoothing circuit to the inductor L2 of the output stage smoothing circuit. The semiconductor switching element TR2 is provided between the connection point of the semiconductor switching element TR1 and the inductor L2 on the positive electrode and the negative electrode.

[0025] For example, the chopper circuit 1111 performs a step-down operation by alternately switching the semiconductor switching elements TR1 and TR2 between ON and OFF states at a duty ratio calculated by a calculation described later. The inductors L1 and L2 store energy by switching the semiconductor switching elements TR1 and TR2, respectively, and supply the energy to the subsequent stage. Note that the operation and configuration of the chopper circuit 1111 are not limited to this example and may be modified as appropriate.

[0026] The first resistor R1 is a resistor for detecting the output current of the converter circuit 111. The current reverse flow prevention element D1 is a reverse flow prevention element such as a diode. For example, the diode is disposed in the rear stage of the first resistor R1 and in the front stage of the output terminal OPTP1 of the converter circuit 11 with its cathode facing the output terminal OPTP1.

[0027] The positive terminal of the converter circuit 111 is connected to the output terminal OPTP1. The output terminals OPTP1, ..., OPTPn of the converter circuits 111, ..., 11n are connected to each other via a positive bus voltage line BUS HOT and are further connected to the positive terminal of the load 30. The negative terminal of the converter circuit 111 is connected to the output terminal OPTN1. The output terminals OPTN1, ..., OPTNn of the converter circuits 111, ..., 11n are connected to each other via a negative bus voltage line BUS RTN and are further connected to the negative terminal of the load 30.

[0028] Even if the output voltages generated by the chopper circuits in each converter circuit 110 vary between converter circuits 110, the presence of a current backflow prevention element D1 at the output of each converter circuit 110 makes it possible to prevent the output current of each converter circuit 110 from flowing back toward each solar cell array.

[0029] The drive circuit 1115 of the converter circuit 111 , the differential amplifier 1118 A, the A / D converter 1118 B, and the determination processing unit 1119 are a functional unit for controlling the power conversion by the chopper circuit 1111 . The A / D converter 1116 , the calculation processing section 1117 , and the determination processing section 1119 of the converter circuit 111 are functional sections for adjusting the control of the power conversion by the chopper circuit 1111 using information from the common circuit 120 .

[0030] Next, the common circuit 120 will be described. Common circuit 120 acquires the voltage (potential difference) between the positive bus voltage line BUS HOT and the negative bus voltage line BUS RTN in order to control the fluctuation of the bus voltage supplied to load 30 within a predetermined allowable voltage fluctuation range. The voltage between the positive bus voltage line BUS HOT and the negative bus voltage line BUS RTN corresponds to the voltage of battery 40. The voltage of battery 40 is a high voltage that cannot be directly handled by electronic circuits. Therefore, a voltage obtained by resistively dividing the voltage of battery 40 (voltage BAT_V of battery 40) is used in subsequent processing.

[0031] The common circuit 120 supplies each converter circuit 110 with information on the number of stages n (e.g., the number of systems) of the multiple converter circuits 110 for causing each of the multiple converter circuits 110 to perform CC charging control, and information indicating the charging state of the battery 40 for causing the CV charging control.

[0032] For example, the common circuit 120 includes a resistor 121, a differential amplifier 122, a differential amplifier 123, an A / D converter 124, and an arithmetic processing unit 125.

[0033] Resistor 121 is a resistor for detecting the current flowing through battery 40. The current flowing through battery 40 includes a battery charging current that flows during charging and a battery discharging current that flows during discharging. The differential amplifier 122 amplifies the voltage generated across the resistor 121 by a predetermined amplification factor.

[0034] The differential amplifier 123 amplifies the voltage BAT_V of the battery 40 at a predetermined amplification factor. For example, the voltage BAT_V of the battery 40, with the ground potential set as the reference potential, is supplied to two input terminals of the differential amplifier 123. The differential amplifier 123 amplifies the voltage BAT_V of the battery 40 by a predetermined amplification factor and outputs the amplified voltage. An input terminal of an A / D converter 124 is connected to an output terminal of the differential amplifier 123. The A / D converter 124 samples the output voltage of the differential amplifier 123 at a predetermined period and converts it into a digital value. An input terminal of an arithmetic processing unit 125 is connected to an output terminal of the A / D converter 124.

[0035] The arithmetic processing unit 125 is a functional unit that performs desired arithmetic operations by executing a program using a processor mounted on, for example, a central processing unit (CPU), a field programmable gate array (FPGA), or the like. For example, the arithmetic processing unit 125 performs a predetermined calculation based on information on the number n of converter circuits, battery internal impedance information, and information on the output value of the A / D converter 124. The arithmetic processing unit 125 outputs the result of the calculation and the information on the number n of converter circuits as information to be supplied to each converter circuit 110. Details of the calculation by the arithmetic processing unit 125 will be described later.

[0036] The common circuit 120 supplies each converter circuit 110 with an output signal from the differential amplifier 122, the calculation result from the calculation processing section 125, and information on the number n of converter circuits.

[0037] [Explanation of operation] A more specific example of charging control by the power supply control device 10 will be described with reference to FIGS. Fig. 2 is a flowchart of the calculation process related to the charging control by the common circuit 120. Fig. 3 is a flowchart of the calculation process related to the charging control by the converter circuit 110. Fig. 4 is a diagram for explaining the charging control in the power supply control device 10.

[0038] The following is an example of charging control (battery charging control) of the battery 40 by the power supply control device 10 shown in Fig. 1. The battery charging control by the power supply control device 10 is performed according to the following operations. The electric power generated by the electric power generating device 2 is supplied to the load 30 via each converter circuit 110 and is also used to charge the battery 40 .

[0039] The power supply control device 10 prevents overcharging during charging in a simple manner by combining two types of control in the charging control of the battery 40. These two types of charging control are as follows.

[0040] Battery charging current control (BAT_CC control) Battery charging voltage control (BAT_CV control)

[0041] (BAT_CC control overview) The BAT_CC control in this embodiment is an example of constant current charging control (CC charging control). For example, the power supply control device 10 detects the battery charging current during charging using the common circuit 120, and transmits a signal whose frequency varies according to the detection result to each converter circuit. As described above, the battery charging current is the current that flows through the battery 40 during charging. In the illustrated configuration, the current flowing through the battery 40 can be detected. Each converter circuit 110 A / D converts, calculates, and determines the signal level that changes according to the current flowing through the battery 40 during charging, and controls the duty ratio (=ON time / (ON time+OFF time)) of the semiconductor switching elements TR1 and TR2 using a drive circuit that uses PWM control. The BAT_CC control of this embodiment is capable of performing control different from the constant current control using the result of detecting the output current of the converter circuit 110. For example, when the result of detecting the output current of the converter circuit 110 is used for the constant current control, the control does not distinguish between the current flowing to the battery 40 and the current flowing to the load 30, but rather functions to keep the output current of the converter circuit 110 constant. In contrast, the BAT_CC control of this embodiment can achieve control that reduces the influence of the current flowing from each converter circuit 110 to the load 30 by using information (magnitude, direction) of the current that flowed to the battery 40 during charging.

[0042] (BAT_CV control overview) The power supply control device 10 detects the BAT voltage during charging using the common circuit 120, A / D converts it, performs calculations, and transmits the results to each converter circuit 110. As described above, the BAT voltage during charging is the terminal voltage of the battery 40 during charging. Each converter circuit 110 makes a judgment based on the transmitted results and controls the duty ratio (=ON time / (ON time+OFF time)) of the semiconductor switching elements TR1, TR2 in the drive circuit 1115 by PWM control. The BAT_CV control of this embodiment allows control different from that in which the terminal voltage of the battery 40 is adjusted by voltage control. In the BAT_CV control, the terminal voltage of the battery 40 and internal impedance information (internal impedance value r) of the battery 40 are used to convert variables related to the control into the dimension of current. By using the internal impedance information, the BAT_CV control makes it possible to reduce the influence of the voltage drop caused by the internal impedance 40r and to integrate the main control into current control.

[0043] Both of these BAT_CC and BAT_CV controls are intended to prevent overcharging of the battery 40. Therefore, if a state occurs during either of these controls that would prevent an overcharge state, it is advisable to adjust the operating point of the charging control in a direction that reduces the charging current. In other words, it is advisable to move the operating point of each of the converter circuits 110 in a direction that reduces the output current (CNV_I1 to CNV_In).

[0044] Next, an example of the processing by the common circuit 120 related to the BAT_CC control and the BAT_CV control will be described. 2, the common circuit 120 acquires the internal impedance value r of the battery 40 (S11). For example, the internal impedance value r of the battery 40 is defined as a predetermined constant. Note that if an internal impedance value r (data) that can be used as a constant is already stored and there is no need to change the internal impedance value r, this process can be omitted.

[0045] The common circuit 120 acquires the value of the voltage BAT_V via the differential amplifier 123 and the A / D converter 124 (S12).

[0046] The common circuit 120 acquires a BAT_CV reference value (S13). For example, the BAT_CV reference value is defined as a predetermined constant. Note that if a BAT_CV reference value (data) that can be used as a constant is already stored and there is no need to change the BAT_CV reference value, this process can be omitted.

[0047] The common circuit 120 acquires the number of converter circuits n (S14). For example, the number of converter circuits n is specified as a predetermined constant. Note that if the number of converter circuits n (data) available as a constant is already stored and there is no need to change the number of converter circuits n, this process can be omitted. Note that the number of converter circuits n may be the number of implemented converter circuits 110 or the number of activated converter circuits 110 among the implemented converter circuits 110.

[0048] The common circuit 120 calculates ΔIcv (S15). The common circuit 120 supplies a part of the results of the above processing to the converter circuit 110 at the subsequent stage.

[0049] (Example of BAT_CC control) When battery charging current control (BAT_CC control) is performed by a plurality of converter circuits 110, information on the “number of converter circuits n” is sent from the common circuit 120 to each converter circuit 110.

[0050] As shown in FIG. 3, the converter circuit 110 obtains ΔIcv from the common circuit 120 (S21).

[0051] The converter circuit 110 acquires the value of the current BAT_I via the differential amplifier 122 of the common circuit 120 (S22).

[0052] The converter circuit 110 acquires the BAT_CC reference value (S23). For example, the BAT_CC reference value is defined as a predetermined constant. Note that if a BAT_CC reference value (data) that can be used as a constant is already stored and there is no need to change the BAT_CC reference value, this process can be omitted.

[0053] The converter circuit 110 acquires the number of converter circuits n from the common circuit 120 (S24). Note that if the converter circuit 110 already holds the number of converter circuits n (data) that can be used as a constant and there is no need to change the number of converter circuits n, this process can be omitted.

[0054] The arithmetic processing unit 1117 of the converter circuit 110 calculates ΔIcc (S25).

[0055] Here, an example of a case where the determinations of ΔIcv and ΔIcc are performed separately will be described, deviating from Fig. 3. In the following description, the determination process of ΔIcv and the determination process of ΔIcc will be described separately.

[0056] In the process of determining ΔIcc, for example, the calculation processor 1117 of each converter circuit 110 obtains ΔIcc based on the quotient of subtracting the BAT_CC reference value from the battery charging current (BAT_I) and dividing the result by the number n of converter circuits. In other words, ΔIcc is obtained by converting the difference between the actual measurement value and the control target value for the battery voltage into the difference in the battery charging current by dividing the difference by the internal impedance value r. The above relationship is shown in equation (1).

[0057] ΔIcc = ((BAT_I) - (BAT_CC reference value)) / n (1)

[0058] Incidentally, the resolution (minimum setting resolution) for setting the control variable CNV_I1 is defined as ΔIcnv (positive number).

[0059] The determination processing unit 1119 of each converter circuit 110 compares, for example, ΔIcnv (a positive number) with ΔIcc.

[0060] (1) When the absolute value of ΔIcc is greater than ΔIcnv (positive number) The result of this comparison means that the difference between the actual battery charging current value and the control target value is greater than the minimum setting resolution. Therefore, the determination processing unit 1119 adjusts the control variable CNV_I1 based on the result of the determination as follows.

[0061] If the sign of ΔIcc is positive, the control variable CNV_I1 is decreased. If the sign of ΔIcc is negative, the control variable CNV_I1 is increased.

[0062] The drive circuit 1115 determines a duty ratio for driving the semiconductor switching elements TR1 and TR2 based on the control variable CNV_I1. The control variable CNV_I1 becomes a command value for the drive circuit 1115. By such control, the battery charging current (BAT_I) can be made to approach the BAT_CC reference value.

[0063] (2) When the absolute value of ΔIcc is smaller than ΔIcnv (positive number) The result of this comparison means that the difference between the actual battery charging current (battery charging current (BAT_I)) and the control target value BAT_CC reference value is smaller than the minimum setting resolution. In other words, since the battery charging current (BAT_I) is being controlled to match the target value, it is advisable to control so as to maintain this control variable CNV_I1. This condition is equivalent to providing a dead band for the difference when the battery charging current (BAT_I) is near the target value.

[0064] (Example of BAT_CV control) Internal impedance information (internal impedance value r) and information on the BAT_CV reference value are provided from the outside to the common circuit 120 of the power supply control device. For example, the common circuit 120 acquires this internal impedance information and information on the BAT_CV reference value, writes it into an internal storage area, and holds it. The calculation processing unit 125 of the common circuit 120 obtains ΔIcv based on the quotient obtained by dividing the difference obtained by subtracting the BAT_CV reference value from the battery voltage (BAT_V) by the internal impedance value r. In other words, ΔIcv is obtained by converting the difference between the actual measurement value and the control target value of the battery voltage by the internal impedance value r into the difference in the battery charging current. The above relationship is shown in equation (2).

[0065] ΔIcv = ((BAT_V) - (BAT_CV reference value)) / r (2)

[0066] The determination processing unit 1119 of each converter circuit 110 compares, for example, ΔIcnv (a positive number) with ΔIcv.

[0067] (1) When the absolute value of ΔIcv is greater than ΔIcnv (positive number) The result of this comparison means that the difference between the actual battery voltage (value converted into battery charging current) and the control target value is greater than the minimum setting resolution. Therefore, the determination processing unit 1119 adjusts the control variable CNV_I1 based on the result of the determination as follows.

[0068] If the sign of ΔIcv is positive, the control variable CNV_I1 is decreased. If the sign of ΔIcv is negative, the control variable CNV_I1 is increased.

[0069] The drive circuit 1115 determines the duty ratio for driving the semiconductor switching elements TR1 and TR2 based on the control variable CNV_I1. By such control, it is preferable to bring the battery voltage (BAT_V) closer to the BAT_CV reference value.

[0070] (2) When the absolute value of ΔIcv is smaller than ΔIcnv (positive number) The result of this comparison means that the difference between the actual battery voltage (value converted into battery charging current) and the control target value is smaller than the minimum setting resolution. That is, since the battery voltage (BAT_V) is being controlled to coincide with the target value, it is advisable to perform control so as to maintain this control variable CNV_I1. This condition is equivalent to providing a dead band for the difference when the battery voltage (BAT_V) is near the target value.

[0071] According to the above embodiment, the process of determining ΔIcv and the process of determining ΔIcc can be performed separately. As described above, it is understood that the BAT_CC control and the BAT_CV control can be performed independently.

[0072] The BAT_CC control and the BAT_CV control are processes for detecting specific states having different conditions, and can be performed in parallel. This description will be continued by returning to Fig. 3. The embodiment shown here is an example of determination using a combination of ΔIcv and ΔIcc.

[0073] After completing step S25 in FIG. 3, the determination processing unit 1119 of each converter circuit 110 determines ΔIcv and ΔIcc.

[0074] When ΔIcv is equal to or greater than ΔIcnv (positive number), or when ΔIcc is equal to or greater than ΔIcnc (positive number), the determination processing unit 1119 decreases the control variable CNV_I1 (S27A). The drive circuit 1115 operates each converter circuit 110 by reducing the duty ratio of the PWM control (S27B).

[0075] Instead, when the absolute value of ΔIcv is less than ΔIcnv (positive number) and the absolute value of ΔIcc is less than ΔIcnc (positive number), the determination processing unit 1119 maintains the control variable CNV_I1 (S28A). The drive circuit 1115 operates each converter circuit 110 by maintaining the duty ratio of the PWM control (S28B).

[0076] Instead, when ΔIcv is equal to or smaller than −ΔIcnv (positive number) and ΔIcc is equal to or smaller than −ΔIcnc (positive number), the determination processing unit 1119 increases the control variable CNV_I1 (S29A). The drive circuit 1115 operates each converter circuit 110 by increasing the duty ratio of the PWM control (S29B).

[0077] By operating each converter circuit 110 according to the above process, it becomes possible to configure a combination of multiple converter circuits 110 (power converters) and perform constant current charging control (CC charging control) and constant voltage charging control (CV charging control) in a simpler manner.

[0078] FIG. 4 shows the relationship between the voltage and the charging current of the battery 40. The charging state of the battery 40 may vary depending on the remaining charge, the magnitude of the load current, the deterioration state of the battery 40, etc. The ranges in Fig. 4 are divided based on the voltage and the magnitude of the charging current of the battery 40. An example of the divisions shown here corresponds to the explanation of Fig. 3 above. The range where the voltage and charging current are relatively large is the range where the charging current is controlled to decrease, and the range where the voltage and charging current are relatively small is the range where the charging current is controlled to increase. In between these ranges, the range where the charging current is controlled to be maintained is specified.

[0079] According to the above embodiment, the power conversion system 1 includes a plurality of converter circuits 110 arranged between the power generation device 2 and one battery 40 (cell), and a common circuit 120 (common controller) that supplies each converter circuit 110 with information on the number of converter circuits 110 for causing each converter circuit 110 to perform CC charge control, and information indicating the charging state of the battery 40 for performing CV charge control. The plurality of converter circuits 110 are connected to each other at their output sides, and are connected to the one battery 40 so as to be chargeable. The plurality of converter circuits 110 convert the power supplied from the power generation device 2 by either constant current charge control (referred to as CC charge control) or constant voltage charge control (referred to as CV charge control). The common circuit 120 calculates first information, which is information indicating the charging state of the battery 40, using internal impedance information (r) of the battery 40 and the voltage of the battery 40. As a result, the power conversion system 1 is configured by combining a plurality of power converters, and can perform constant current charging control (CC charging control) and constant voltage charging control (CV charging control) in a simpler manner.

[0080] The common circuit 120 calculates the difference between the voltage of the battery 40 and the target voltage of the battery 40 by the value (r) of the internal impedance information of the battery 40 as the first information.

[0081] The plurality of converter circuits 110 includes a determination processing unit 1119. The determination processing unit 1119 may receive information on the number of systems (number of stages n) of the plurality of converter circuits 110 from the chopper circuit 1111 of the main circuit of the converter circuit 110 and the common circuit 120, and information indicating the charging state of the battery 40, and calculate a control target value for adjusting the amount of power conversion of the main circuit of the converter circuit 110.

[0082] In the case of the above-mentioned CC charging control, the common circuit 120 supplies the number of systems of the multiple converter circuits 110 and the magnitude of the charging current of the battery of one system to each of the multiple converter circuits 110 as second information indicating the charging state of the battery 40. The plurality of converter circuits 110 are each adapted to convert the power supplied from the power generating device 2 using the above-mentioned first information and second information.

[0083] The common circuit 120 detects the charging current by a current detector (resistor 121) provided on the ground electrode side of one of the batteries 40, and supplies the magnitude of the detected charging current to each of the multiple converter circuits 110. The multiple converter circuits 110 may each convert the power supplied from the power generating device based on the magnitude of the detected charging current.

[0084] Here, an application example will be described with reference to FIG. FIG. 5 is a configuration diagram of the device 3 in the power conversion system 1. As shown in FIG. The device 3 shown in this figure includes a power generation device 2, a battery 40, and a power conversion system 1.

[0085] For example, the device 3 is an airborne vehicle such as a satellite. The power generation device 2 includes a solar cell array 20 divided into a plurality of systems. Such a device 3 is configured by combining a plurality of power converters 110, and can perform constant current charging control (CC charging control) and constant voltage charging control (CV charging control) in a simpler manner.

[0086] (Study on the reliability of power conversion system 1) The reliability of the power conversion system 1 of the present embodiment can be improved in the following manner. It is possible to increase reliability against accidental failures by configuring the multiple converter circuits 110 in the power conversion system 1 to have redundancy. For example, even if one of the converter circuits 110 fails, if the required power conditions are satisfied, the failed part can be partially degenerated to allow the power conversion system 1 and its load 30 to operate normally.

[0087] For example, when multiple converter circuits 110 are subjected to battery charging current control (BAT_CC control), information on the "number of converter circuits n" is sent from the common circuit 120 to each converter circuit 110, and each converter circuit 110 is configured to calculate the required current value by itself. This makes it possible to reconfigure the power supply control device 10 accordingly, even if there is a change in the number of available converter circuits 110. As described above, it has become possible to realize BAT_CC control with a simple control algorithm.

[0088] Furthermore, when performing battery voltage control (BAT_CV control) using multiple converter circuits 110, it is required to appropriately distribute the output current of each converter circuit 110 and perform BAT_CV control based on the distribution. In this embodiment, the BAT_CV control is integrated into the BAT_CC control by incorporating information on the "internal impedance value r of the battery 40" into the control algorithm. This simplifies the control by integrating the BAT_CV control in multiple converter circuits 110 into the BAT_CC control of each converter circuit 110. At this time, the "internal impedance r" can be a value suitable for the actual battery 40. For example, it is advisable to set a value close to the ideal value of the actual battery 40 to the "internal impedance r" and perform battery charging control.

[0089] Second embodiment The second embodiment will be described with reference to FIGS. In the second embodiment, a case will be described in which processing similar to that in the first embodiment is performed by processing using a processor such as a CPU and a program.

[0090] FIG. 6 is a flowchart of the charging control according to the present disclosure. When the control unit 81 including the acquisition unit and the calculation processing unit of the embodiment is implemented in a computer, for example, a computer shown in FIG. 7 can be applied. FIG. 7 also serves as a schematic block diagram illustrating an example configuration of a computer according to the present disclosure. In the configuration shown in FIG. 7, a computer 800 includes a CPU 810, a main memory device 820, an auxiliary memory device 830, an interface 840, and a non-volatile recording medium 850. FIG. 8 is a diagram showing a configuration example of a power conversion system 1 according to the present disclosure.

[0091] The power supply control device 10, the common circuit 120, the converter circuit 110, or a part thereof of the power conversion system 1 may be implemented in the computer 800. In this case, the operation of each of the above-mentioned processing units is stored in the auxiliary storage device 830 in the form of a program. The CPU 810 reads the program from the auxiliary storage device 830, develops it in the main storage device 820, and executes the above-mentioned processing according to the program. The CPU 810 also secures a storage area corresponding to each of the above-mentioned storage units in the main storage device 820 according to the program. Communication between each device and other devices is executed by the interface 840 having a communication function and performing communication according to the control of the CPU 810. The interface 840 also has a port for the nonvolatile recording medium 850, and reads information from the nonvolatile recording medium 850 and writes information to the nonvolatile recording medium 850.

[0092] For example, when the power supply control device 10 is implemented in a computer 800, the operations of the converter circuit 110 and the common circuit 120, including the arithmetic processing unit, the judgment processing unit, the drive circuit, etc., are stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it into the main storage device 820, and executes the above-mentioned processing according to the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communications between the power supply control device 10 and other devices are performed by an interface 840 having a communication function and operating under the control of the CPU 810.

[0093] When the common circuit 120 is implemented in the computer 800, the operation of each part of the common circuit 120 is stored in the form of a program in the auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it in the main storage device 820, and executes the above-mentioned processing in accordance with the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communication with other devices such as the converter circuit 110 is performed by an interface 840 having a communication function and operating under the control of the CPU 810.

[0094] When the converter circuit 110 is implemented in a computer 800, the operation of each unit of the converter circuit 110 is stored in the form of a program in an auxiliary storage device 830. The CPU 810 reads the program from the auxiliary storage device 830, loads it in the main storage device 820, and executes the above-mentioned processing in accordance with the program. Furthermore, the CPU 810 reserves a memory area in the main memory device 820 in accordance with the program. Communication with other devices such as the common circuit 120 is performed by an interface 840 having a communication function and operating under the control of the CPU 810.

[0095] For example, the multiple converter circuits 110 in the power conversion system 1 are disposed between the power generation device 2 and one system of batteries 40 (cells). The output sides of the multiple converter circuits 110 are connected to each other and to the one system of cells so as to be chargeable.

[0096] As shown in FIG. 6, the power conversion system 1 configured as described above supplies each converter circuit 110, which converts the power supplied from the power generation device 2 using either constant current charging control or constant voltage charging control, with information on the number of systems of the multiple converter circuits 110 for causing each of the multiple converter circuits 110 to perform CC charging control, and information indicating the charging state of the battery 40 for performing CV charging control (S110).

[0097] The power conversion system 1 calculates information indicating the state of charge of the battery 40 using internal impedance information of the battery 40 and the voltage of the battery 40 (S120).

[0098] In this way, the power conversion system 1 includes a plurality of converter circuits 110 arranged between a power generation device and one system of batteries, the output sides of the plurality of converter circuits 110 being connected to each other and to one system of batteries in a chargeable manner, and each of the converter circuits 110 converts the power supplied from the power generation device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), and a common circuit 120 serving as a common controller that supplies each of the power converters with information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery for performing CV charging control. The common circuit 120 calculates first information, which is information indicating the charging state of the battery, using internal impedance information of the battery and the voltage of the battery. As a result, the power conversion system 1 is configured by combining a plurality of power converters, and can perform constant current charging control (CC charging control) and constant voltage charging control (CV charging control) in a simpler manner.

[0099] Any one or more of the above-mentioned programs may be recorded in the non-volatile recording medium 850. In this case, the interface 840 may read the program from the non-volatile recording medium 850. Then, the CPU 810 may directly execute the program read by the interface 840, or may temporarily store the program in the main storage device 820 or the auxiliary storage device 830 and execute it.

[0100] Note that a program for executing all or part of the processing performed by any of the computers in the power conversion system 1 may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing of each part. Note that the term "computer system" as used herein includes hardware such as an OS (Operating System) and peripheral devices. Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), as well as storage devices such as hard disks built into computer systems. The above-mentioned program may be for realizing part of the above-mentioned functions, or may be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

[0101] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included.

[0102] For example, the solar cell array 20 is an example of a power source that supplies electric power, and may be replaced with another power source having a similar function. In this embodiment, the solar cell array 20 is mounted on an artificial satellite, for example, but may be installed on the ground, etc.

[0103] In this embodiment, the current backflow prevention element D1 is an example of a backflow prevention element that prevents current from flowing backward to the corresponding solar cell array 20, and is configured using a diode, but may be replaced with another current backflow prevention element having a similar function.

[0104] In this embodiment, field effect transistor elements (MOSFETs) are used as the switch elements TR1 and TR2, but other switch elements may be used.

[0105] In this embodiment, capacitors are used for C1 and C2, but other capacitive power storage elements may be used. Also, in this embodiment, coils are used for L1 and L2, but other inductive power storage elements may be used. In this embodiment, resistors R1 and R2 are connected, but R1 and R2 are resistors for current detection, and resistors R1 and R2 are not necessary if current is detected by another method (such as a Hall element).

[0106] In this embodiment, the functions of the common circuit 120 and the converter circuits 110 are allocated as shown in FIG. 1, but the BAT_I detection function performed by the common circuit 120 may be realized in at least one of the multiple converter circuits 110.

[0107] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0108] Note that some or all of the above-described embodiments may be described as follows, but are not limited to the following.

[0109] (Appendix 1) a plurality of power converters arranged between a power generation device and one system of batteries, the output sides of the plurality of power converters being connected to each other and to the one system of batteries in a chargeable manner, and each of the power converters converts the power supplied from the power generation device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control); a common controller that supplies each of the power converters with information on the number of systems of the plurality of power converters for performing CC charge control on each of the plurality of power converters, and information indicating a charging state of the battery for performing CV charge control; Equipped with The common controller includes: calculating first information indicating a charging state of the battery using internal impedance information of the battery and a voltage of the battery; Power conversion systems.

[0110] (Appendix 2) The common controller includes: a difference between a voltage of the battery and a target voltage of the battery is divided by a value of internal impedance information of the battery, and the result is calculated as the first information; 2. The power conversion system according to claim 1.

[0111] (Appendix 3) The plurality of power converters include A main circuit of a power converter; a determination processing unit that receives information on the number of systems of the plurality of power converters and information indicating a charging state of the battery from the common controller and calculates a control target value for adjusting the power conversion amount of a main circuit of the power converter; Equipped The power conversion system according to claim 1 or 2.

[0112] (Appendix 4) The common controller includes: In the case of the CC charging control, the number of systems of the plurality of power converters and the magnitude of the charging current of the battery of the one system are supplied to each of the plurality of power converters as second information indicating the charging state of the battery, The plurality of power converters include converting the electric power supplied from the electric power generating device using the first information and the second information, respectively; 4. The power conversion system according to claim 1, wherein the power conversion system comprises:

[0113] (Appendix 5) The common controller includes: Detecting the charging current by a current detector provided on the ground electrode side of the one system of batteries, and supplying the magnitude of the detected charging current to each of the plurality of power converters; The plurality of power converters include converting the power supplied from the power generating device based on the magnitude of the detected charging current; 5. The power conversion system according to claim 4.

[0114] (Appendix 6) A power generation device; A storage battery, The power conversion system according to claim 1, An apparatus comprising:

[0115] (Appendix 7) The common controller includes: a difference between a voltage of the battery and a target voltage of the battery is divided by a value of internal impedance information of the battery, and the result is calculated as the first information; 7. The apparatus according to claim 6 above.

[0116] (Appendix 8) The plurality of power converters include A main circuit of a power converter; a determination processing unit that receives information on the number of systems of the plurality of power converters and information indicating a charging state of the battery from the common controller and calculates a control target value for adjusting the power conversion amount of a main circuit of the power converter; Equipped The power conversion system according to claim 6 or 7.

[0117] (Appendix 9) The common controller includes: In the case of the CC charging control, the number of systems of the plurality of power converters and the magnitude of the charging current of the battery of the one system are supplied to each of the plurality of power converters as second information indicating the charging state of the battery, The plurality of power converters include converting the electric power supplied from the electric power generating device using the first information and the second information, respectively; 9. The power conversion system according to claim 6, wherein the power conversion system comprises:

[0118] (Appendix 10) The common controller includes: Detecting the charging current by a current detector provided on the ground electrode side of the one system of batteries, and supplying the magnitude of the detected charging current to each of the plurality of power converters; The plurality of power converters include converting the power supplied from the power generating device based on the magnitude of the detected charging current; 10. The power conversion system according to claim 9.

[0119] (Appendix 11) a plurality of power converters are arranged between a power generation device and one system of batteries, the output sides of the plurality of power converters are connected to each other and are connected to the one system of batteries in a chargeable manner, and each of the power converters converts the power supplied from the power generation device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), and the plurality of power converters are supplied with information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery for causing the plurality of power converters to perform CV charging control; Calculating first information indicating a state of charge of the battery using internal impedance information of the battery and a voltage of the battery; A power conversion control method comprising:

[0120] (Appendix 12) a difference between a voltage of the battery and a target voltage of the battery is divided by a value of internal impedance information of the battery, and the result is calculated as the first information; 12. The power conversion control method according to claim 11.

[0121] (Appendix 13) The plurality of power converters include A main circuit of a power converter; a determination processing unit that receives information on the number of systems of the plurality of power converters and information indicating a charging state of the battery, and calculates a control target value for adjusting the power conversion amount of a main circuit of the power converter; Equipped The power conversion control method according to claim 11 or 12.

[0122] (Appendix 14) In the case of the CC charging control, the number of systems of the plurality of power converters and the magnitude of the charging current of the battery of the one system are supplied to each of the plurality of power converters as second information indicating the charging state of the battery, The plurality of power converters include converting the electric power supplied from the electric power generating device using the first information and the second information, respectively; 14. The power conversion control method according to any one of claims 11 to 13.

[0123] (Appendix 15) Detecting the charging current by a current detector provided on the ground electrode side of the one system of batteries, and supplying the magnitude of the detected charging current to each of the plurality of power converters; The plurality of power converters include converting the power supplied from the power generating device based on the magnitude of the detected charging current; 15. The power conversion control method according to claim 14.

[0124] (Appendix 16) A power conversion system including a plurality of power converters disposed between a power generating device and a battery in one system, the output sides of the plurality of power converters being connected to each other and connected to the battery in a rechargeable manner, supplying information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charge control and information indicating the charging state of the battery for performing CV charge control to each of the power converters, which respectively convert the power supplied from the power generation device using either constant current charge control (referred to as CC charge control) or constant voltage charge control (referred to as CV charge control); Calculating first information indicating a state of charge of the battery using internal impedance information of the battery and a voltage of the battery; A program for executing the above.

[0125] (Appendix 17) a difference between a voltage of the battery and a target voltage of the battery is divided by a value of internal impedance information of the battery, and the result is calculated as the first information; The program according to claim 16.

[0126] (Appendix 18) The plurality of power converters include A main circuit of a power converter; a determination processing unit that receives information on the number of systems of the plurality of power converters and information indicating a charging state of the battery, and calculates a control target value for adjusting the power conversion amount of a main circuit of the power converter; Equipped The program according to claim 16 or 17.

[0127] (Appendix 19) In the case of the CC charging control, the number of systems of the plurality of power converters and the magnitude of the charging current of the battery of the one system are supplied to each of the plurality of power converters as second information indicating the charging state of the battery, The plurality of power converters include converting the electric power supplied from the electric power generating device using the first information and the second information, respectively; 19. A program according to any one of claims 16 to 18.

[0128] (Appendix 20) Detecting the charging current by a current detector provided on the ground electrode side of the one system of batteries, and supplying the magnitude of the detected charging current to each of the plurality of power converters; The plurality of power converters include converting the power supplied from the power generating device based on the magnitude of the detected charging current; The program according to claim 19. [Explanation of symbols]

[0129] 1. Power Conversion System 2. Power Generation Device 10 Power supply control device 20, 21, 22, ..., 2n solar array 40 Battery (BAT) 110, 111, 112, 11n Converter circuit (power converter) 120 Common circuit (common controller)

Claims

1. a plurality of power converters arranged between a power generation device and a battery in one system, the output sides of the plurality of power converters being connected to each other and to the battery in a chargeable manner, the plurality of power converters respectively converting the power supplied from the power generation device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control); a common controller that supplies each of the power converters with information on the number of systems of the plurality of power converters for performing CC charge control on each of the plurality of power converters, and information indicating a charging state of the battery for performing CV charge control; Equipped with The common controller includes: calculating first information indicating a state of charge of the battery using internal impedance information of the battery and a voltage of the battery; Power conversion systems.

2. The common controller includes: a difference between a voltage of the battery and a target voltage of the battery is divided by a value of internal impedance information of the battery, and the result is calculated as the first information; The power conversion system of claim 1 .

3. The plurality of power converters include A main circuit of a power converter; a determination processing unit that receives information on the number of systems of the plurality of power converters and information indicating a charging state of the battery from the common controller and calculates a control target value for adjusting the power conversion amount of a main circuit of the power converter; Equipped The power conversion system of claim 1 .

4. The common controller includes: In the case of the CC charging control, the number of systems of the plurality of power converters and the magnitude of the charging current of the battery of the one system are supplied to each of the plurality of power converters as second information indicating the charging state of the battery, The plurality of power converters include converting the electric power supplied from the electric power generating device using the first information and the second information, respectively; The power conversion system of claim 1 .

5. The common controller includes: Detecting the charging current by a current detector provided on the ground electrode side of the one system of batteries, and supplying the magnitude of the detected charging current to each of the plurality of power converters; The plurality of power converters include converting the power supplied from the power generating device based on the magnitude of the detected charging current; The power conversion system of claim 4 .

6. A power generating device; A storage battery, The power conversion system according to claim 1 ; An apparatus comprising:

7. a plurality of power converters are arranged between a power generation device and one system of batteries, the output sides of the plurality of power converters are connected to each other and are connected to the one system of batteries in a chargeable manner, and each of the power converters converts the power supplied from the power generation device by either constant current charging control (referred to as CC charging control) or constant voltage charging control (referred to as CV charging control), and the plurality of power converters are supplied with information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charging control, and information indicating the charging state of the battery for causing the plurality of power converters to perform CV charging control; Calculating first information indicating a state of charge of the battery using internal impedance information of the battery and a voltage of the battery; A power conversion control method comprising:

8. A power conversion system including a plurality of power converters disposed between a power generating device and a battery in one system, the output sides of the plurality of power converters being connected to each other and connected to the battery in a rechargeable manner, supplying information on the number of systems of the plurality of power converters for causing each of the plurality of power converters to perform CC charge control and information indicating the charging state of the battery for performing CV charge control to each of the power converters, which respectively convert the power supplied from the power generation device using either constant current charge control (referred to as CC charge control) or constant voltage charge control (referred to as CV charge control); Calculating first information indicating a state of charge of the battery using internal impedance information of the battery and a voltage of the battery; A program for executing the above.

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