动态无功补偿装置，仅仅是补偿无功功率，它的响应很快，就是补偿速度很快。

有源滤波器，主要是用来滤除电网中的谐波，但是它有补偿无功功率的能力，而且补偿的响应速度更快。目前的产品中，有源滤波器的功率容量相对较小，而且价格较高，所以鲜有专门用来做无功补偿动态无功补偿装置，仅仅是补偿无功功率，它的响应很快，就是补偿速度很快。

有源滤波器，主要是用来滤除电网中的谐波，但是它有补偿无功功率的能力，而且补偿的响应速度更快。目前的产品中，有源滤波器的功率容量相对较小，而且价格较高，所以鲜有专门用来做无功补偿-Run a first simulation with an alpha firing angle of 19 degrees. You should get a DC voltage level of 500 kV. Now, look inside Scope1. Compare the currents flowing into Bus B1 (Iabc_B1, axis 2) with those flowing into Bus B2 (Iabc_B2, axis 3). You can see that the harmonic filters almost eliminate the harmonics generated by the converter. If you use the FFT tool of the powergui, you will find that the harmonic filters reduce the THD of the current injected in the system from 9　to 0.7 . You can also perform other simulations with various values of alpha. Notice the impact on the DC level and on the generated harmonics.