JP-7855875-B2 - Distributed power systems

Inventors

• 野村 康祐
• 笠嶋 亮輔
• 小林 健二
• 馬渕 雅夫
• 湊 惇朗

Assignees

• オムロン株式会社

Dates

Publication Date

20260511

Application Date

20220303

Claims (7)

1. A distributed power supply system comprising multiple power conditioners that convert DC power input from solar cells that generate DC power into AC power and supply it to a load, Based on the ratio to a predetermined value set for each of the aforementioned power conditioners, the output of the aforementioned power conditioners is performed. Based on the aforementioned ratio, the upper limit of the output command value for each of the multiple power conditioners is determined. A distributed power supply system characterized by adjusting the ratio such that the sum of the output values of the plurality of power conditioners maintains the predetermined value.
2. The distributed power supply system according to claim 1, characterized in that the predetermined value is a limit value for the total sum of the output values of the plurality of power conditioners.
3. The distributed power supply system according to claim 1 or 2, characterized in that the output value is a power value or a current value.
4. The distributed power system according to any one of claims 1 to 3, characterized in that adjusting the ratio includes increasing the ratio and decreasing the ratio.
5. The number of the aforementioned power conditioners is n (where n is an integer of 3 or more), A distributed power supply system according to any one of claims 1 to 4, characterized in that when the ratios are adjusted so that the sum of the ratios of n-1 power conditioners out of n units is 100%, and the ratio of the power conditioners other than the n-1 unit out of n units is 0%, the total output value of the n-1 power conditioners remains at the predetermined value, the output of the power conditioners other than the n-1 unit is stopped.
6. The number of the aforementioned power conditioners is 2. A distributed power supply system according to any one of claims 1 to 4, characterized in that when the ratio is adjusted so that the ratio of one of the two power conditioners becomes 100% and the ratio of the other of the two power conditioners becomes 0%, the output of one of the two power conditioners remains at the predetermined value, the output of the other of the two power conditioners is stopped.
7. The distributed power supply system according to any one of claims 1 to 6, characterized in that the plurality of power conditioners perform maximum power point tracking control to produce output.

Description

This invention relates to a distributed power supply system comprising multiple inverters. There is a distributed power supply system that includes a battery storage power conditioner that operates a battery storage unit connected to the power grid, and a PV (photovoltaic) power conditioner that operates a PV (photovoltaic) unit connected to the power grid (see, for example, Patent Document 1). Japanese Patent Publication No. 2021-145538 Figure 1 shows a schematic configuration of a distributed power supply system.Figure 2 shows the configuration of a distributed power supply system equipped with a controller.Figure 3 is a flowchart showing the processing flow according to this embodiment.Figures 4(A) to 4(D) show an example of a process for adjusting the ratio of power conditioners. [Examples of application] The following describes an example of the application of the present invention with reference to the drawings. As shown in Figure 1, the distributed power supply system 1 according to this example is equipped with four single-phase power conditioners 20A, 20B, 20C, and 20D. Power conditioners 20A and 20B are power conditioners for storage batteries, and power conditioner 20A has a single-phase inverter 10A. Power conditioner 20B has a single-phase inverter 10B. DC power from batteries 7A and 7B is input to single-phase inverters 10A and 10B. Power conditioners 20C and 20D are power conditioners for solar cells. Power conditioner 20C has a single-phase inverter 10C, and power conditioner 20D has a single-phase inverter 10D. DC power generated by solar cells 7C and 7D is input to single-phase inverters 10C and 10D. Power conditioners 20A to 20D convert the input DC power into AC power and supply it to the load. The outputs of single-phase inverters 10A to 10D are connected to a single-phase system 1A and single-phase consumer loads 2 and 3. Single-phase system 1A is, for example, a single-phase commercial power system. The outputs of single-phase inverters 10A to 10D are also connected to a three-phase independent operation load 8. Three-phase independent operation load 8 is an example of a three-phase load. During grid-connected operation, the single-phase inverters 10A to 10D are connected in parallel, and the AC power from the single-phase output voltages of the single-phase inverters 10A to 10D is supplied to the single-phase consumer loads 2 and 3. Also during grid-connected operation, the three-phase independent operation load 8 is supplied with AC power from a three-phase system 1B at three-phase voltage. Three-phase system 1B is, for example, a three-phase commercial power system. On the other hand, during independent operation, the AC power from the output voltages of the single-phase inverters 10A to 10D is supplied to the independent operation load 8. During this independent operation, a three-phase voltage is generated based on the output voltage of the single-phase inverters 10A to 10D. Based on the ratio to a predetermined value set for power conditioners 20C and 20D, the upper limit of the output command value for power conditioners 20C and 20D is determined, and output is performed. The ratio of power conditioners 20C and 20D is adjusted so that the sum of the output values of power conditioners 20C and 20D maintains a predetermined value. By adjusting the ratio of power conditioners 20C and 20D so that the sum of the output values of power conditioners 20C and 20D maintains a predetermined value, it is prevented that the sum of the output values of power conditioners 20C and 20D will exceed the predetermined value. Since it is prevented that the sum of the output values of power conditioners 20C and 20D will exceed the predetermined value, it is possible to prevent the output of power conditioners 20C and 20D from becoming excessive. This prevents the current flowing through components such as terminal blocks and relays from exceeding the component's capacity, and thus prevents damage to the components. The predetermined value may be determined based on the component capacity of the terminal block and relay, or it may be determined by experimentation or simulation. The predetermined value may also be the required value (power value or current value) for power conditioners 20C and 20D from at least one of the single-phase consumer loads 2 and 3 and the standalone operation load 8. In Figure 1, the distributed power system 1 is equipped with two power conditioners 20A and 20B for storage batteries, but the number of power conditioners for storage batteries can be increased or decreased. The number of power conditioners for storage batteries may be one or three or more. In Figure 1, the distributed power system 1 is equipped with two power conditioners 20C and 20D for solar cells, but the number of power conditioners for solar cells (hereinafter referred to as PV power conditioners) can be changed. The number of PV power conditioners may be three or more. Also, the number of power condition