Methods to prevent reactive power from large solar power plants from being fed back into the grid at night

Abstract

This invention relates to a method for preventing reactive power from large solar power plants from being fed back into the grid at night. The method regulates the reactive power fed back into the regional grid by solar power plants at night. The nighttime reactive power regulation method includes an analysis unit, a simulation unit, and a control unit that are interconnected. The analysis unit calculates and obtains optimization instructions based on the reactive power value; the simulation unit calculates and obtains regulation instructions; and the control unit controls the increase or decrease of inverter groups according to the regulation instructions from the simulation unit to eliminate or compensate for reactive power in real time. Thus, by utilizing the existing inverter groups of the solar power plant in conjunction with the analysis unit, simulation unit, and control unit of this invention, the purpose of regulating the reactive power fed back into the regional grid by the solar power plant at night can be achieved.

Claims

1. A method for preventing reactive power from a large solar power plant from being fed back into the grid at night, used to regulate reactive power fed back into a regional power grid by a solar power plant at night, the solar power plant including multiple inverter groups and a real-time monitoring unit, the inverter groups absorbing the reactive power, the real-time monitoring unit monitoring and obtaining the value of the reactive power in real time, the method for regulating nighttime reactive power includes: providing an analysis unit electrically and signalally connected to the real-time monitoring unit, and obtaining an optimization command based on the value of the reactive power; providing a simulation unit signalally connected to the real-time monitoring unit and the analysis unit, and obtaining at least one adjustment command through simulation calculation based on the value of the reactive power and the optimization command; and providing a control unit electrically and signalally connected to the simulation unit and the inverter groups, the control unit receiving the adjustment command from the simulation unit, and controlling the opening and closing of the inverter groups according to the adjustment command to eliminate or compensate for the reactive power in real time.

2. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the optimization instructions include the number of inverter groups to be turned on and the location of the inverter groups to be turned on in the area where the solar power plant is located.

3. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the analysis unit obtains the optimization instruction by performing multiple calculations and converging through a genetic algorithm.

4. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein when the real-time monitoring unit detects a positive residual value of the reactive power, the simulation unit issues one of the adjustment commands to cause the control unit to control an increase in the number of inverters in the inverter group; or when the real-time monitoring unit detects a negative residual value of the reactive power, the simulation unit issues the other of the adjustment commands to cause the control unit to control a decrease in the number of inverters in the inverter group.

5. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the control unit is further electrically and signal-connected to a monitoring and data acquisition system (SCADA) to acquire at least one operating data of the regional power grid and to perform real-time scheduling of the inverter groups based on the operating data.

6. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the simulation unit has an update interval for rolling simulation and correction of the reactive power.

7. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the inverter groups are grouped according to a feeder length, a geographical distribution, or a capacity specification.

8. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the optimization instructions are used to minimize residual reactive power and line losses.

9. The method for preventing reactive power from large solar power plants from being fed back into the grid at night as described in claim 1, wherein the control unit is provided with a hierarchical scheduling mechanism, and when the residual reactive power value exceeds a preset threshold, the inverter groups are started or shut down step by step by the hierarchical scheduling mechanism.

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