小水电机组的变转速运行方案及控制策略研究

Research on Variable Speed Operation Scheme and Control Strategy for Small Hydropower Unit

水电机组变速运行可极大提高机组运行效率与调节品质,是解决小水电机组运行效率低、调节品质差的有效手段。讨论了小水电机组的变速运行方案及控制策略,建立了适宜于小水电机组变速方案的数学模型及控制策略模型,通过仿真对比了不同控制策略下的机组转速、机组功率的变化过程。结果表明:小水电机组更适合采用基于全功率变流器与同步发电机的变速方案,同时控制系统适宜采用网侧变流器控制变流器直流母线电压与输出的无功功率,采用机侧变流器控制机组有功功率,采用调速器控制机组转速的策略,仿真中机组功率无反调现象,且稳定速度快,机组功率可在0.9s进入稳定值的4‰且不再偏离。研究结果可为小水电资源高效开发提供参考。

Variable speed operation can greatly improve the operation efficiency and regulation performance on hydropower unit.It is an effective way to solve the low operation efficiency and poor regulation quality on small hydropower unit.This paper discusses the variable speed operation schemes and control strategies for small hydropower units.The suitable system mathematical model and control strategy model are built for small hydropower units.The variable speed unit dynamic process of different control strategies is compared by simulation.The results show that,small hydropower unit is more suitable for using variable speed scheme based on full power converter and synchronous generator,at the same time,the control system control strategy suitable for the grid side converter control inverter DC bus voltage and reactive power output,the machine side converter control active power,the governor control speed of unit.The power anti-regulation phenomenon does not appear in simulation.And the active power stability time can be achieved in 0.9 seconds.The results of this paper can provide reference for the efficient development of small hydropower resources.