应用MATLAB/SIMULINK仿真研究铁磁谐振

Research of Rerroresonance Simulation Using MATLAB/SIMULINK

鉴于中性点直接接地的电力系统中屡屡因投切断路器或隔离开关而激发铁磁谐振现象 ,分析了该现象产生的原因和条件 ,建立了母线电压互感器 (TV)的仿真模型 ,利用MATLAB内建的仿真工具实现了铁磁谐振 (由母线TV非线性励磁电感同断路器均压电容和系统对地电容匹配所致 )暂态过程数字仿真。仿真结果表明 ,TV的励磁电阻 (铁损 )对铁磁谐振有重要影响。铁损越大 ,谐振越强烈。铁损减小 ,利于抑制谐振。最后 ,仿真比较了两种不同消谐方法的作用及效果 ,验证了消谐方案 (通过间接降低TV励磁电阻来抑制铁磁谐振 )

In the neutral-grounded power system, ferroresonance overvoltage caused by switching circuit breakers or disconnectors occurs frequently. This simulation model of bus TV, employs simulation implement of MATLAB to achieve digital calculation and simulation of the ferroresonance transient process due to matching of non-liner exciting inductance of the bus TV and the breakers' grading capacitance and the capacitance to ground of system. It is proved from the results that the value of core loss of TV is the important factor to ferroresonance. The greater the value is, the intenser the resonance is. Decreasing the value is the key to suppressing this kind of resonance. At last, to testify the feasibility of suppressing the ferroresonance by indirectly decreasing the core loss of TV, two ways about ferroresonance suppression and their effects are simulated and compared. The feasible measures of preventing and suppressing ferroresonance are presented as well.