新能源同步机与调相机在高比例新能源电网中应用的比较

Comparison of MGP and Synchronous Condenser in High Proportion Renewable Energy Grid

针对高比例新能源电网的电压稳定问题和新能源脱网风险,新能源同步机(Motor Generator Pair,MGP)系统和调相机均能发挥重要作用。为对比二者的动态特性,本文介绍了MGP结构和控制策略,分析了MGP的无功调节原理和机械隔离作用。推导了调相机的动态调节特性及无功调节能力的影响参数。在PSCAD中分别搭建了MGP和调相机接入新能源并网系统的仿真模型,对比了不同故障情况下MGP和参数优化前、后调相机的动态特性,结果表明MGP和调相机都具备抑制电压跌落的能力,而MGP的机械隔离作用可以隔离故障对逆变器和新能源机组的大部分影响,防止新能源大量脱网。

Aiming at the problem of voltage stability and the risk of renewable energy that trriped of the grid in high proportion renewable energy grid,motor generator pair(MGP)system and synchronous condenser can both play an important role.In order to compare the dynamic characteristics of the MGP and synchronous condenser,the structure and control method of MGP are introduced,the mechanical isolation function of MGP and its principle of reactive power regulation and are analyzed in this paper.The dynamic regulation characteristic of the condenser and the its influence parameters of the reactive power regulation ability are derived.The simulation models of MGP and synchronous condenser connected to new energy grid system are built in PSCAD,respectively.In order to compare the dynamic characteristics of MGP and synchronous condenser that before and after being optimized,different faults are set in the simulation model.The results show that both MGP and synchronous condenser have the ability to restrain the voltage sag,but MGP can isolate most of the impact that faults act on inverter and renewable energy unit and avoid outage of large-scale of renewable energy from grid.