Solar power generation system and control device

Abstract

Provided is a photovoltaic power generation system (2) comprising: a plurality of solar battery panels (4); a plurality of power conversion devices (6) that convert DC power supplied from the plurality of solar battery panels (4) into AC power adapted to a power system (PS); and a control device (10) that controls operation of the plurality of power conversion devices (6). The control device (10) includes a total output value computation unit (20) for computing a total effective power value representing the magnitude of effective power that can be currently output from all of the plurality of power conversion devices (6), a difference computation unit (22) for computing a first difference between an upper-limit total command value and the total effective power value, and an upper-limit command value computation unit (24) for computing, on the basis of the first difference and the effective power value of each of the plurality of power conversion devices (6), an individual upper-limit command value representing the upper limit of effective power output individually from each of the plurality of power conversion devices (6). Through the above, provided are the photovoltaic power generation system (2) and control device (10) that are capable of suppressing excessive lowering of the total value of the effective power of AC power to be supplied from the plurality of power conversion devices (6) to the power system (PS).

Claims

1. Multiple solar panels, A plurality of power conversion devices are provided corresponding to each of the plurality of solar panels, which convert the DC power supplied from the plurality of solar panels into AC power corresponding to the power grid, and supply the converted AC power to the power grid. A control device that controls the power conversion operation of the plurality of power converters, Equipped with, The control device is An output total value calculation unit receives an active power value representing the current output amount of active power for each of the multiple power converters, and calculates a total active power value representing the current output amount of active power from all of the multiple power converters by adding up the active power values ​​of each of the multiple power converters. A difference calculation unit receives the input of the total active power value and a total upper limit command value representing the upper limit of the active power output from all of the multiple power converters, and calculates the first difference between the total upper limit command value and the total active power value. An upper limit command value calculation unit that receives the input of the first difference and the input of the active power value of each of the plurality of power converters, and calculates an individual upper limit command value that represents the upper limit of the active power to be output individually from each of the plurality of power converters based on the active power value of each of the plurality of power converters and the first difference, It has, The upper limit command value calculation unit is: The second difference is calculated by dividing the first difference by the number of power converters whose difference obtained by subtracting the current active power value from the current individual upper limit command value is less than or equal to the first reference value. The difference obtained by subtracting the current active power value from the current individual upper limit command value is less than or equal to the first reference value. By adding the calculated second difference to the current individual upper limit command value of the power converter, a new individual upper limit command value less than or equal to the first reference value is calculated for the power converter. The total active power value of the power converter is calculated by subtracting the current active power value from the current individual upper limit command value, and the difference obtained is greater than the first reference value. A solar power generation system in which, among the power conversion devices whose power is greater than the first reference value, the difference obtained by subtracting the current active power value from the total active power value is less than or equal to the second reference value, and the individual upper limit command value is not changed.

2. The solar power generation system according to claim 1, wherein the upper limit command value calculation unit sets the individual upper limit command value to an output command value obtained by dividing the total upper limit command value by the number of power converters, for power converters whose difference obtained by subtracting the current active power value from the total active power value is greater than the second reference value among the power converters whose upper limit command value is greater than the first reference value.

3. A control device that controls the power conversion operation of a plurality of power converters, each provided in accordance with a plurality of solar panels, which converts DC power supplied from the plurality of solar panels into AC power corresponding to a power grid, and supplies the converted AC power to the power grid, An output total value calculation unit receives an active power value representing the current output amount of active power for each of the multiple power converters, and calculates a total active power value representing the current output amount of active power from all of the multiple power converters by adding up the active power values ​​of each of the multiple power converters. A difference calculation unit receives the input of the total active power value and a total upper limit command value representing the upper limit of the active power output from all of the multiple power converters, and calculates the first difference between the total upper limit command value and the total active power value. An upper limit command value calculation unit that receives the input of the first difference and the input of the active power value of each of the plurality of power converters, and calculates an individual upper limit command value that represents the upper limit of the active power to be output individually from each of the plurality of power converters based on the active power value of each of the plurality of power converters and the first difference, Equipped with, The upper limit command value calculation unit is: The second difference is calculated by dividing the first difference by the number of power converters whose difference obtained by subtracting the current active power value from the current individual upper limit command value is less than or equal to the first reference value. The difference obtained by subtracting the current active power value from the current individual upper limit command value is less than or equal to the first reference value. By adding the calculated second difference to the current individual upper limit command value of the power converter, a new individual upper limit command value less than or equal to the first reference value is calculated for the power converter. The total active power value of the power converter is calculated by subtracting the current active power value from the current individual upper limit command value, and the difference obtained is greater than the first reference value. A control device that does not change the individual upper limit command value for power converters whose power conversion value is greater than the first reference value and whose difference obtained by subtracting the current active power value from the total active power value is less than or equal to the second reference value.

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