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EP-4738677-A1 - POWER SUPPLY SYSTEM AND CONTROL PROGRAM

EP4738677A1EP 4738677 A1EP4738677 A1EP 4738677A1EP-4738677-A1

Abstract

In a power supply system (10), a rechargeable battery module (30, 60) including a rechargeable battery (31, 61) and a conversion circuit (40, 70) is connected to a power supply bus (11, 12). A positive electrode and a negative electrode of the rechargeable battery are individually connected to a primary-side terminal pair (41, 42, 71, 72) of the conversion circuit, and the rechargeable battery is serially connected to a secondary-side terminal pair (47, 48, 77, 78) of the conversion circuit. The power supply system includes a bus voltage setting unit (16a) that sets a bus voltage requirement value which is a voltage required for the power supply bus and a control unit (16b) that controls an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module becomes the bus voltage requirement value. The bus voltage setting unit sets the bus voltage requirement value such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit.

Inventors

  • ITO, MITSUTAKA
  • KURACHI, TAISUKE

Assignees

  • DENSO CORPORATION

Dates

Publication Date
20260506
Application Date
20240613

Claims (13)

  1. A power supply system (10, 210) in which a rechargeable battery module (30, 60, 90) including a rechargeable battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the rechargeable battery to a primary-side terminal pair (41, 42, 71, 72) and outputs the converted power from a secondary-side terminal pair (47, 48, 77, 78) is connectable to a power supply bus (11, 12), wherein a positive electrode and a negative electrode of the rechargeable battery are individually connected to the primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to the secondary-side terminal pair of the conversion circuit, the power supply system includes a bus voltage setting unit (16a) that sets a bus voltage requirement value which is a voltage required for the power supply bus, and a control unit (16b) that controls an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module approaches the bus voltage requirement value, and the bus voltage setting unit sets the bus voltage requirement value such that an output power of the conversion circuit becomes not more than a rated power of the conversion circuit or such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit.
  2. The power supply system according to claim 1, wherein the bus voltage setting unit lowers the bus voltage requirement value to lower than the present bus voltage requirement value, in response to an output power of the conversion circuit becoming not less than a prescribed power value which is smaller than the rated power, in response to an output voltage of the conversion circuit becoming not less than the rated voltage, or in response to an output current of the conversion circuit becoming not less than a prescribed current value which is smaller than a rated current of the conversion circuit.
  3. The power supply system according to claim 1 or 2, further comprising a current adjustment unit (16c) that decreases an output current of the conversion circuit to less than a present output current, in response to an output power of the conversion circuit becoming not less than a prescribed power value which is smaller than the rated power, in response to an output voltage of the conversion circuit becoming not less than the rated voltage, or in response to an output current of the conversion circuit becoming not less than a prescribed current value which is smaller than a rated current of the conversion circuit.
  4. The power supply system according to claim 3, wherein the rechargeable battery module is a first rechargeable battery module (30), the power supply system further comprises a second rechargeable battery module (60) equivalent to the rechargeable battery module, and the current adjustment unit decreases an output current of the conversion circuit of the first rechargeable battery module to less than a present output current and increases an output current of the conversion circuit of the second rechargeable battery module to more than a present output current, in response to an output power of the conversion circuit of the first rechargeable battery module becoming not less than the prescribed power value, in response to an output voltage of the conversion circuit of the first rechargeable battery module becoming not less than the rated voltage, or in response to an output current of the conversion circuit of the first rechargeable battery module becoming not less than the prescribed current value.
  5. The power supply system according to claim 1 or 2, wherein the rechargeable battery module is a first rechargeable battery module (30), the power supply system further comprises a second rechargeable battery module (60) equivalent to the rechargeable battery module, and the control unit charges the rechargeable battery of the first rechargeable battery module from the rechargeable battery of the second rechargeable battery module, in response to an output power of the conversion circuit of the first rechargeable battery module becoming not less than a prescribed power value which is smaller than the rated power, in response to an output voltage of the conversion circuit of the first rechargeable battery module becoming not less than the rated voltage, or in response to an output current of the conversion circuit of the first rechargeable battery module becoming not less than a prescribed current value which is smaller than a rated current of the conversion circuit.
  6. The power supply system according to claim 1 or 2, further comprising a resistance adjustment unit (16d) that lowers an internal resistance of the rechargeable battery of the rechargeable battery module including the conversion circuit to lower than a present internal resistance, in response to an output power of the conversion circuit becoming not less than a prescribed power value which is smaller than the rated power, in response to an output voltage of the conversion circuit becoming not less than the rated voltage, or in response to an output current of the conversion circuit becoming not less than a prescribed current value which is smaller than a rated current of the conversion circuit.
  7. The power supply system according to claim 6, wherein the resistance adjustment unit lowers an internal resistance of the rechargeable battery to lower than a present internal resistance by changing a temperature of the rechargeable battery from a present temperature.
  8. The power supply system according to claim 1 or 2, wherein a prescribed rechargeable battery module (120) that includes a rechargeable battery (121) and does not include the conversion circuit is connected to the power supply bus.
  9. The power supply system according to claim 8, wherein a load (28) is connected to the rechargeable battery module, and the power supply system further comprises an interruption-connection circuit (22, 24, 25, 27) that interrupts and connects the rechargeable battery module and the load to the power supply bus.
  10. The power supply system according to claim 8, wherein a load (28) is connected to the power supply bus and the prescribed rechargeable battery module, and the power supply system further comprises an interruption-connection circuit (120a, 120b) that interrupts and connects the prescribed rechargeable battery module to the power supply bus and the load.
  11. The power supply system according to claim 8, further comprising a switching circuit (22 to 27, 211 to 214) that switches the rechargeable battery module and the prescribed rechargeable battery module between parallel connection and serial connection.
  12. The power supply system according to claim 1 or 2, further comprising a plurality of the rechargeable battery modules (30, 60, and 90), and a switching circuit (22 to 27, 211 to 214) that switches the plurality of the rechargeable battery modules between parallel connection and serial connection.
  13. A control program applied to a power supply system (10, 210) in which a rechargeable battery module (30, 60, 90) including a rechargeable battery (31, 61, 91) and a conversion circuit (40, 70, 100) that converts power input from the rechargeable battery to a primary-side terminal pair (41, 42, 71, 72) and outputs the converted power from a secondary-side terminal pair (47, 48, 77, 78) is connectable to a power supply bus (11, 12), a positive electrode and a negative electrode of the rechargeable battery are individually connected to the primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to the secondary-side terminal pair of the conversion circuit, the control program causing a computer (16) to execute processing of setting a bus voltage requirement value which is a voltage required for the power supply bus, processing of controlling an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module approaches the bus voltage requirement value, and processing of setting the bus voltage requirement value such that an output power of the conversion circuit becomes not more than a rated power of the conversion circuit or such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit.

Description

[Cross Reference to Related Application] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2023-108738 filed June 30, 2023, the contents of each of which are incorporated herein by reference. [Technical Field] The present disclosure relates to a power supply system. [Background Art] For example, there is a rechargeable battery module in which a positive electrode and a negative electrode of a rechargeable battery are individually connected to an input terminal pair of a conversion circuit, and the rechargeable battery is serially connected to an output terminal pair of the conversion circuit (see PTL 1). According to the rechargeable battery module described in PTL 1, a voltage that is a sum of an output voltage Vb of the rechargeable battery and an output voltage Vo of the conversion circuit is an output voltage Vm of the rechargeable battery module. Therefore, it is possible to lower an output voltage Vo required for the conversion circuit when an output voltage Vm is required for the rechargeable battery module, as compared with a rechargeable battery module in which a rechargeable battery is parallelly connected to an output terminal pair of a conversion circuit. Therefore, it is possible to reduce a rated capacity of a conversion circuit. [Citation List] [Patent Literature] PTL 1: JP 2022-23722 A [Summary of the Invention] In the rechargeable battery module according to PTL 1, the rated capacity of the conversion circuit can be reduced due to the effect of the circuit configuration itself of the rechargeable battery module. However, there is yet room for improvement in further reducing a rated capacity of a conversion circuit, as a power supply system in which a rechargeable battery module is connected to a power supply bus. The present disclosure has been made to solve the above-described problem, and has as its main object to further reduce a rated capacity of a conversion circuit in a power supply system in which a rechargeable battery module is connected to a power supply bus. A first measure for solving the above-described problem is a power supply system in which a rechargeable battery module including a rechargeable battery and a conversion circuit that converts power input from the rechargeable battery to a primary-side terminal pair and outputs the converted power from a secondary-side terminal pair is connectable to a power supply bus, in whicha positive electrode and a negative electrode of the rechargeable battery are individually connected to the primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to the secondary-side terminal pair of the conversion circuit,the power supply system includesa bus voltage setting unit that sets a bus voltage requirement value which is a voltage required for the power supply bus, anda control unit that controls an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module approaches the bus voltage requirement value, andthe bus voltage setting unit sets the bus voltage requirement value such that an output power of the conversion circuit becomes not more than a rated power of the conversion circuit or such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit. According to the above-described configuration, a power supply system is configured that a rechargeable battery module including a rechargeable battery and a conversion circuit that converts power input from the rechargeable battery to a primary-side terminal pair and outputs the converted power from a secondary-side terminal pair is connected to a power supply bus. Therefore, power can be supplied from a rechargeable battery module to a power supply bus. Note that a power supply bus is a power path (common power path) that is shared for connecting a plurality of circuits, devices, and apparatuses to exchange power in a power supply system. A positive electrode and a negative electrode of the rechargeable battery are individually connected to the primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to the secondary-side terminal pair of the conversion circuit. According to such a configuration, a voltage that is a sum of an output voltage Vb of a rechargeable battery and an output voltage Vo of a conversion circuit is an output voltage Vm of a rechargeable battery module. Therefore, it is possible to lower an output voltage Vo required for a conversion circuit when an output voltage Vm is required for a rechargeable battery module, as compared with a rechargeable battery module in which a rechargeable battery is parallelly connected to a secondary-side terminal pair of a conversion circuit. Therefore, a rated voltage of a conversion circuit can be lowered, and a rated capacity of a conversion circuit can be accordingly reduced. Here, a bus voltage