高压大容量静止同步补偿器的优化节能运行

Optimized Energy-saving Operation of High-voltage High-capacity STATCOM

为了实现高压大容量静止同步补偿器(static synchronous compensator,STATCOM)的节能运行,以南方电网35kV/±200MVA链式STATCOM为研究背景,从STATCOM的器件选择、控制方式、控制策略等多方面进行了讨论。对比了IGBT、IGCT和IEGT等功率开关器件的开通损耗、关断损耗和驱动功率,提出从节能角度采用IEGT更适合目标系统。分析了硬开关PWM逆变器的缺点,提出在链式STATCOM的PWM控制方式逆变器中采取辅助谐振软开关拓扑结构,可减少损耗,应对逆变器载波频率、无功波形质量和装置损耗之间的矛盾。考虑到目标STATCOM的并联连接方式,基于对现场运行数据的分析,建立了多台STATCOM并联运行的节能优化数学模型,可用于制订节能运行策略。基于对广东电网暂态无功需求的分析,提出STATCOM与传统的电容/电抗器无功补偿设备配合控制策略:STATCOM优先动作,需要补偿的稳定容量达到设定限值后,转投/切电容器或电抗器。仿真结果与现场测试数据表明,采用以上节能方式,可降低约30%的STATCOM损耗。

In order to achieve the energy-saving operation of high-voltage high-capacity static synchronous compensator（STATCOM）,we discussed the switch choice,controlling method,and controlling strategies of STATCOM based on the 35 kV/±200 MVA cascade STATCOM adopted in China Southern Power Grid.After comparing the opening and closing losses and the driving power of IGBT,IGCT and IEGT,it is suggested that IEGT is the best choice from the aspect of energy saving.Furthermore,we analyzed the disadvantages of PWM inverter,and proposed to adopt an assistant-resonant soft-switching topology in PWM controlling inverters of the target system,which could reduce the operating loss and deal with the conflicts among the carrier frequency,reactive power waveform and device losses of inverters.Considering the parallel operation of target STATCOM,an energy-saving optimizing mathematic model of multiple parallel connected STATCOM for establishing energy-saving operation strategy was established.Moreover,analyzing the transient reactive power requirements of Guangdong Power Grid,we proposed a cooperating controlling strategy for STATCOM and existing reactive power compensation devices：STATCOM act firstly,then turn into/out the capacitor or reactor when the compensation capacity was at the setting quota.Further simulative and experimental data indicate that,by using the proposed methods,about 30% of the STATCOM loss can be saved.