POWER SUPPLY SYSTEM, CONTROL METHOD THEREOF, AND RECORDING MEDIUM

• US 20150039152A1
• Filed: 07/28/2014
• Published: 02/05/2015
• Est. Priority Date: 07/30/2013
• Status: Active Grant

• Current Assignee: NEC Platforms, Ltd. (NEC Corporation)
• Original Assignee: NEC Platforms, Ltd. (NEC Corporation)
• Inventors: UCHIKAWA, Takafumi
• Granted Patent: US 9,667,101 B2
• Time in Patent Office: Days
• US Class Current: 700/297
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/12 Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages

Abstract

A power supply system controls output powers of a plurality of power supply apparatus for realizing optimal conversion efficiency between input power and output power. The power supply system includes a plurality of power conversion units that convert an input power supplied from the input side into an output power for supplying the output power to a load connected to the output side; a power measurement unit that measures the output power of the power conversion unit; and a power supply control unit that calculates the input power to the power conversion unit in response to the output power of the power conversion units measured by the power measurement unit, and calculates the output power of the power conversion unit realizing the minimum calculated input power as an optimal output power, and controls the power conversion units based on the calculated optimal output power.

Claims

1. A power supply system comprising:

a plurality of power supply units that convert an input power into an output power and supply the output power to a load;

a power measurement unit, which is connected between an output side of the power supply units and the load, that measures the output power output from the power supply units; and

a power supply control unit that calculates an optimal output power realizing a minimum input power to the power supply units in accordance with the output power measured by the power measurement unit, and controls the power supply units based on the calculated optimal output power.

2. The power supply system according to claim 1, wherein

the power supply control unit calculates the input power to the power supply units in accordance with the output power measured by the power measurement unit, based on an input-output conversion model expressing power conversion between input power to the power supply units and output power to be output from the power supply units.

3. The power supply system according to claim 2, wherein

the input-output conversion model is a quadratic function of the output power of the power supply unit.

4. The power supply system according to claim 2, wherein

the power measurement unit measures a sum of output powers of the plurality of power supply units to be consumed in the load, and

the power supply control unit calculates an optimal output power realizing a minimum sum of input powers to the plurality of power supply units, based on the sum of the output powers measured by the power measurement unit, and the input-output conversion model with respect to each of the power supply units, and adjusts the output power of each of the power supply units, based on the calculated optimal output power.

5. The power supply system according to claim 4, wherein

in a condition that it is assumed that output powers of one or more specific power supply units included in the plurality of power supply units are equal to each other, and output powers of remaining power supply units are equal to each other,

the power supply control unit calculates the optimal output power, for the each power supply unit, that realizes the minimum sum of input powers to the plurality of power supply units, and adjusts the output power of each of the power supply units, based on the calculated optimal output power.

6. The power supply system according to claim 2, further comprising:

a power input unit, which a rated maximum output power is set, connected to an input side of the power supply units;

a drive circuit unit connected to the output side of the power supply units, the drive circuit unit being a load for which a rated maximum power consumption is set; and

a device control unit, wherein

the device control unit calculates the minimum sum of input power to the plurality of power supply units, by assuming that the rated maximum power consumption is consumed in the load, and compares between the calculated minimum sum of input power, and the rated maximum output power of the power input unit.

7. The power supply system according to claim 1, wherein

the power supply control unit controls the output power of the power supply units by adjusting output voltages of the plurality of power supply units.

8. The power supply system according to claim 1, further comprising:

a battery unit on the output side of the power supply units.

9. A control method for a power supply system, comprising:

measuring output powers output from a plurality of power supply units that convert an input power into the output powers and supply the output powers to a load;

calculating an optimal output power for the power supply units realizing a minimum input power to the power supply units in accordance with the measured output powers; and

controlling the power supply units based on the calculated optimal output power.

10. A non-transitory computer-readable storage medium recorded with a control program that controls an operation of a power supply system, the control program causing a computer to execute:

a process of acquiring a measurement result of output powers output from a plurality of power supply units;

a process of calculating an optimal output power realizing a minimum input power to be input to the power supply unit in accordance with the measurement result of output powers; and

a process of controlling the output powers of the power supply units based on the calculated optimal output power.