并网CIG系统的小干扰稳定性解析分析

Analytical analysis of small disturbance stability of grid-connected CIG system

针对含锁相环(phase-lockedloop,PLL)的以换流器联接的发电设备(converterinterfacedgeneration,CIG)并网系统解析稳定性的欠缺,研究并网CIG系统的稳定性,建立单电压源换流器-无穷大电源系统的极点和内环电流时间常数、系统工作点、线路参数以及PLL控制参数之间的关系,应用劳斯判据得出稳定条件的解析表达式,并进行化简。利用的解析条件发现诱发系统不稳定的因素、原理,准确地预测系统稳定性并在确保系统稳定的前提下提供控制器参数的可行范围。电磁暂态仿真结果验证了所提解析条件的正确性与准确性.

Because of the lack of analytical stability conditions of grid-connected converter interfaced generation(CIG)system with phase-locked loop(PLL),this paper studied the stability of grid-connected CIG system.The relationship between the poles and the time constants of the inner loop current,the operating points of the system,the line parameters and the PLL control parameters of the single voltage source converter-infinite power supply system was established.The analytical expressions of the stability conditions were obtained by using the Routh criterion and were simplified to make them more suitable for industrial applications.The analytical conditions proposed in this paper revealed the inducing factors and mechanism of system instability,which could not only predict the stability of the system quickly and accurately,but also provide the feasible range of controller parameters to ensure system stability.The electromagnetic transient simulation results verified the correctness and accuracy of the analytical conditions proposed in this paper.