Governing approach of low-voltage power network harmonic Network harmonic is a strong electricity scope of the harmful substances, to be truly effective eliminating harmonics is no easy task, especially in the low-voltage (below 1000V AC), large current, low impedance source, the filtering device parameters difficult adjustment, and high harmonic amplification reaction. Currently only in theory explored (LV). Adopting LC no source method and solid source method abroad, the latter cost is so high and limited capacity, and is still under development. Our company adopting no source LC filter has successfully developed WXL-harmonic elimination device by use of computer technology, and as a result, Users operating in nearly a year, performance is quite stable by long-term tracking. The method is to force the harmonic currents through the filter circuit rather than through the main transformer, that is, to change the original harmonic current flows through the main transformer's path. Asking for a filter loops with very low harmonic impedance of the loop, but has linear frequency impedance to work frequency; at same time has quite reactive power compensation; at any time shall not give rise to harmonic enlarge. This puts forward high demands for the design of filter loop components, manufacturing materials and process; for this, using imported special materials and components construct a complete filter loop. The performance parameters of the device are presented below, if request more, can read explaining book of products.