微电网发电并网三相电压稳定性控制研究

Research on Three-Phase Voltage Stability Control of Micro-grid Power Generation

作为新能源发电系统,由于其静态和动态特性均与传统同步发电系统相差较大,对传统电力系统的运行方式产生了一定的冲击,所以通过微电网并网的方式来解决。由于微电网系统主要由一些复杂的模型组成,如并网逆变器、线路、负荷等,在电磁暂态过程中使的变流器的动态特性变差和稳定性能降低等问题。在PWM逆变器数学原理的基础上,提出一种依据傅里叶理论建立动态相量法的控制策略,分别取正负序分量的一阶动态相量,减少了模型的计算量。通过对两个模型的仿真和实验结果进行比较分析,结果表明所提方法在需要的精度上可以近似为电磁暂态模型,并且有效的提高了动态性能和稳定性能,加快了仿真速度,节省了仿真时间。

As a new energy power generation system, the static and dynamic characteristics are quite different from the traditional synchronous power generator system. It has a great impact on the traditional operation mode of power system, hence it is solved through the micro grid connection method. As the microgrid system is mainly com- posed of some complicated models, such as grid - connected inverters, lines, and loads model, the dynamic characteristics of the converters deteriorates during the electromagnetic transient process, and the stability performance is reduced. Based on the mathematical principle of PWM inverter, a control strategy based on Fourier theory to establish dynamic phasor method is proposed. It takes the first - order dynamic phasors of positive and negative sequence components respectively, which reduces the computational complexity of the model. By comparing and analyzing the simulation results and experimental results of the two models, the results show that the proposed method can be approxi- mated as the electromagnetic transient model with the required accuracy, and effectively improve the dynamic performance and stability performance, accelerate the simulation speed, and save the simulation time.