基于光伏逆变器的快速功率控制系统研究及应用

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

为使新能源功率输出能快速响应系统有功功率和无功功率平衡需求,文中提出光伏电站毫秒级功率控制的系统性方案。首先,基于光伏逆变器的功率快速交换能力,在光伏电站并网点直采电压、电流,实时监测并网点频率和电压变化,根据一次调频参数计算光伏电站有功出力。在此基础上,通过高速环网通信链路群控光伏逆变器进行有功出力,使得光伏电站具备一次调频能力。在无功功率控制方面,文中通过智能多状态序列判别算法实时计算光伏电站并网点对电力系统的阻抗,根据并网点电压波动实时群控光伏逆变器进行无功出力,使得光伏电站具备动态无功响应能力,从而完成光伏电站功率的快速控制。目前该系统已经在淮安金湖光伏电站中试点运行,现场试验数据说明应用文中提出的控制系统可实现一次调频响应时间小于0.15 s,动态无功响应时间小于30 ms的指标,验证了控制系统的有效性和可行性。

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.