针对二阶广义积分器锁频环在电网同步系统启动和电网电压的参数跳变时会产生频率波动的问题,提出了一种基于自适应锁频环结构的二阶广义积分器的电网同步方法.该方法将反映电网电压的幅值、相位和频率的跳变的电压误差引入锁频环的增益.通过设计合适的锁频环增益,既能够有效抑制相位和幅值跳变引起的频率波动,又能够提高频率跳变时的响应速度.在电网电压正常、不平衡和畸变的情况下对所提出的电网同步方法进行了仿真.仿真结果验证了所提出方法的有效性.
Under the conditions of grid synchronization start up and grid voltage parameter jumps, second order generalized integrator (SOGI) frequency locked loop (FLL) can result in frequency fluctuations which cannot be ignored. To address this problem, this paper proposes a grid synchronization method u- sing SOGI based on an adaptive FLL structure. The voltage error involving the frequency, phase and am- plitude jumps of the grid voltage is introduced for the correction of the FLL gain. The proposed method with a proper FLL gain not only mitigates the frequency fluctuations caused by the phase and amplitude jumps, but also increases the response speed of the frequency jump. The grid synchronization method un- der the normal, unbalanced and distorted grid voltage conditions is simulated. The simulation results veri fy the effectiveness of the proposed method.