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EP-3982529-B1 - POWER SUPPLY SYSTEM

EP3982529B1EP 3982529 B1EP3982529 B1EP 3982529B1EP-3982529-B1

Inventors

  • KATAOKA, TAKUYA
  • IZUMI, KIKUO
  • HIGAKI, YUSUKE
  • JIMICHI, TAKUSHI
  • TAKUNO, TSUGUHIRO

Dates

Publication Date
20260506
Application Date
20190605

Claims (7)

  1. A power supply system_(1) to supply power to a load (3), the power supply system comprising: - a converter (10) to convert AC power or DC power received from a main power source (2) into power with a voltage in accordance with a voltage command value (Vref) and supply the converted power to the load (3); - a detector (20) to detect an operating state of the load (3); and - a controller (30) to operate in an operation mode selected from among a plurality of operation modes and generate the voltage command value (Vref), the operation modes including - a first mode in which the controller (30) generates the voltage command value (Vref) based on the operating state of the load detected by the detector (20) such that power consumption of the load (3) is reduced, and - a second mode in which the controller (30) generates the voltage command value (Vref) based on predetermined setting information or external command information acquired from an external device (4) such that there is no excess or deficiency of the voltage of the power output from the converter (10), and the converter (10) is configured to convert AC power or DC power received from the main power source (2) into DC power with a voltage in accordance with the voltage command value (Vref) and supplying the converted DC power to the load (3).
  2. The power supply system_(1) according to claim 1, wherein when operating in the first mode, the controller (30) is configured to determine an acceptable range of the voltage command value (Vref) based on at least one of an operating state of the load (3), the setting information, and the external command information, and to limit the voltage command value (Vref) such that the voltage command value (Vref) falls within the acceptable range.
  3. The power supply system_(1) according to claim 1 or 2, wherein the controller (30) is configured to select the operation mode based on an operating state of the load (3).
  4. The power supply system_(1) according to any one of claims 1 to 3, wherein the controller (30) is configured to select the operation mode based on the external command information.
  5. The power supply system_(1) according to any one of claims 1 to 4, wherein the detector (20) is configured to detect at least one of power consumption and current of the load (3) as an operating state of the load (3), and the controller (30) is configured to select the operation mode based on a fluctuation rate of the power consumption of the load (3) detected by the detector (20) or a fluctuation rate of the current detected by the detector (20).
  6. The power supply system_(1) according to any one of claims 1 to 4, wherein the controller (30) is configured to select the second mode at start-up of the load (3) and to select the first mode after the start-up of the load (3).
  7. The power supply system_(1) according to any one of claims 1 to 6, wherein the converter (10) is capable of supplying power to a plurality of power distribution systems (LA, LB), and the controller includes a plurality of the controllers (30A, 30B) respectively corresponding to the power distribution systems (LA, LB).

Description

TECHNICAL FIELD The present invention relates to a power supply system that distributes and supplies electric power to a plurality of loads. BACKGROUND ART Power storage batteries have been increasingly used to make use of renewable energy and cope with power failures. For example, a DC power supply and distribution system that supplies and distributes DC power is used as a power supply system used in application of power storage batteries. DC power supply and distribution systems are advantageous in that the number of times of power conversion is reduced and cost efficiency is improved because DC power output from a DC power source is output without being converted into AC power. In addition, there is a high degree of flexibility because the standards of output voltage of DC power supply and distribution systems are not decided yet. A DC power supply and distribution system has been proposed which outputs DC power with a voltage in accordance with a load to the load. For example, Japanese Patent JP 5 092 997 B2 (PTL 1) discloses a system power source that supplies a power supply voltage to a load circuit having a plurality of load regions. This system power source includes a plurality of voltage conversion circuits (DC/DC converters) provided respectively corresponding to the load regions in the load circuit, a data table in which an optimum power supply voltage for current consumption in each load region is stored in advance for each of the load regions, a current detector to detect current consumption of the load circuit, and a voltage controller to perform a process for supplying an optimum power supply voltage corresponding to current consumption of the load circuit to the load circuit by referring to the data table. Document JPH0965648 discloses a power supply using two different voltage references, but does not foreseen to use one of these references to reduce the power. CITATION LIST PATENT LITERATURE PTL 1:Japanese Patent JP 5 092 997 B2 SUMMARY OF THE INVENTION TECHNICAL PROBLEM However, in the system power source described in PTL 1, it is necessary to provide voltage conversion circuits as many as the loads and the data table in order to handle a plurality of loads different in characteristics, and the cost of the entire system is increased. The present invention has been made in order to solve the problem described above, and an object of the present invention is to provide a power supply system capable of improving load efficiency with lower costs. SOLUTION TO PROBLEM A power supply system according to the present invention is a power supply system to supply power to a load and includes a converter, a detector, and a controller. The converter converts AC power or DC power received from a main power source into power with a voltage in accordance with a voltage command value and supplies the converted power to the load. The detector detects an operating state of the load. The controller operates in an operation mode selected from among a plurality of operation modes and generates the voltage command value. The operation modes include a first mode in which the distribution voltage command value is generated based on the operating state of the load detected by the detector and a second mode in which the voltage command value is generated based on predetermined setting information or external command information acquired from an external device. ADVANTAGEOUS EFFECTS OF THE INVENTION The present invention provides a power supply system capable of improving load efficiency with lower costs. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1is a first diagram schematically showing a configuration of a power supply system.FIG. 2is a flowchart showing an example of a process performed when a controller operates in a distribution voltage control mode.FIG. 3is a flowchart showing an example of a process performed when the controller selects an operation mode.FIG. 4is a second diagram schematically showing a configuration of a power supply system.FIG. 5is a diagram showing an example of correspondence between distribution voltage and distribution loss.FIG. 6is a third diagram schematically showing a configuration of a power supply system.FIG. 7is a diagram showing an example of change in operation mode of the controller.FIG. 8is a fourth diagram schematically showing a configuration of a power supply system. DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. Like or corresponding parts in the drawings are denoted by like reference signs and a description thereof is not repeated. First Embodiment Configuration of Power Supply System FIG. 1 is a diagram schematically showing a configuration of a power supply system 1 according to a first embodiment of the present invention. Power supply system 1 is connected to a main power source 2 and a plurality of loads 3. Power supply system 1 converts AC power supplied from main power source 2 into DC power