ITER测试平台无功补偿系统的甩负荷过电压分析

The analysis of load rejection overvoltage of ITER test platform

ITER测试平台无功补偿及谐波抑制系统包含一套由RLC滤波支路和晶闸管控制电抗器(TCR)组成的无功补偿装置,当接入电网时,为防止系统甩负荷对电网的安全性产生影响,通过计算解析研究分析了系统甩负荷时在110kV母线上产生的过电压。结果表明,当因系统故障进行甩负荷时,母线电压上确实会产生一个较高的过电压,其数值已超出国家标准允许范围,可能会对电网产生一定影响,需采取防护措施,即加入了一条由反并联二极管和电阻组成的旁通支路来释放主回路电流以减少过电压。MATLAB的仿真结果也验证了上述结果的正确性。

The ITER test platform contains a reactive power compensation and harmonic suppression system, which consists of the RLC filter branches and thyristor controlled reactor（TCR）. When connected to the grid, in order to prevent the negative effects of load rejection on grid, the load rejection overvoltage at 110kV bus bar by mathematical calculation is analyzed, which shows that there is a high overvoltage on bus bar when the system throws off the load, and its value is not within the allowable range of the national standards and maybe have impact on grid, so we need to take some protective measures. In order to decrease overvoltage, there adds a bypass branch which contains the anti-parallel diode and a resistor to release the main circuit current. The simulation on the whole system with MATLAB verifies the results above.