中压直流综合电力系统发电机并联控制策略

Control strategy of generators in parallel of MVDC integrated power system

针对中压直流综合电力系统多相整流发电机采用传统直流侧电压—功率下垂励磁控制策略,在轻载工况存在功率分配不均的问题,建立了多相整流发电机等效数学模型,理论分析了功率分配不均问题的产生机理,研究了一种按发电机负载率选择电压反馈输入源的改进控制策略,并构建了并联整流发电机短路测试平台,开展了并联机组直流侧短路电流的理论推导、仿真计算与试验测试。对比结果表明,通过轻载时引入交流侧输入电压作为励磁控制器的电压反馈源,可实现并联发电机组轻载正常建压,短路电流峰值按比例分配,验证了所采用策略的有效性。

Aiming at the problem that the power distribution of multiphase rectifier generators of MVDC integrated power system with the traditional DC-side voltage-power droop excitation control strategy may get deteriorated under light load condition,an equivalent mathematical model of the multiphase rectifier generators was established,the mechanism of uneven power distribution was theoretically analyzed,an improved control strategy with proper voltage feedback signals based on the rates of generator loadings was introduced,a testbed for short-circuit performance analysis of the generators was constructed,and theoretical derivation,simulation calculation and experimental testing of DC-side short-circuit currents of generators in parallel were carried out.The comparison results show that adopting the input AC voltages for the excitation control under light load conditions achieves the proper output voltages of generators with light loads and the peak values of short-circuit currents are distributed in proportion,at the same time,the results verified effectiveness of the introduced strategy.