Research and application of rapid power control system based on photovoltaic inverter

Abstract

A systematic solution for millisecond-level power control in photovoltaic (PV) power stations is proposed to enable the new energy power output to rapid response to the balance of active and reactive power demands in the system. Firstly, utilizing the fast power exchange capability of the PV inverter, real-time voltage and current are collected at the grid connection point of the PV power station, and the frequency and voltage changes are monitored to calculate the active power output of the PV power station based on primary frequency regulation parameters. Based on this, the PV inverters are controlled in a group via a high-speed interconnection communication network to achieve primary frequency regulation capability. In terms of reactive power control, an intelligent multi-state sequence discrimination algorithm is employed to calculate the impedance of the grid connection point of the PV power station to the power system in real time. Based on the voltage fluctuation at the grid connection point, the PV inverters are controlled in a group to achieve dynamic reactive power response, thereby achieving rapid power control of the PV power station. The proposed control system has been piloted at the Jinhu PV power station in Huai′an, and the on-site test data shows that the control system can achieve a primary frequency regulation response time of less than 0.15 s and a dynamic reactive power response time of less than 30 ms, thereby verifying the effectiveness and feasibility of the control system.

Keywords

• new energy stations
• inverter
• rapid power control
• dynamic reactive power response
• primary frequency regulation
• on-site test