The general idea of ??harmonic governance. Harmonic governance should first consider the prevention, control source good harmonics generated harmonics generated in the system so that to minimize, they can more easily control or do not have further treatment. Therefore, the choice of equipment and building systems, it should be reduced harmonics as an important condition to consider. For AC and DC communication power supply equipment into two categories: under other conditions the same or a similar situation, UPS system should give priority to 12 pulses or equipment Delta transform the DC system should prefer better rectifying circuit and improve filtering measures The product. Secondly, on the basis of prevention, to consider remedies. Especially for the low-pressure system existing users, because the system has been basically fixed structure, harmonic problems can only be solved through the installation of the reactor control, filters and other remedies. The active harmonic filter device is developed on the basis of passive filter, it's a good filtering effect, within its rated range of reactive power, harmonic control, filtering effect is one hundred percent. It is mainly composed by the power electronics circuits, to produce a harmonic frequency and the same system, the same magnitude, but opposite in phase with the system harmonic current harmonic current cancellation. However, due to power electronics voltage and rated current of development constraints, high costs, the production is also much more complex than the passive filter, the cost would be much higher. Its main application is a computer-controlled system of power supply system, what is the harmonic control, particularly in the office of the power supply system, harmonic control cabinet prices, the plant's computer controlled power supply system. For a single device, the profits are considerable, harmonic control products, but users are generally reluctant to use active filter, the harmonic content, do not filter too clean, they do not endanger other appliances can also a. Harmonic control cabinet prices, learning Connaught Electrical and Mechanical, harmonic control by learning Connaught Mechanical and Electrical Equipment Co., Ltd., Henan. Henan Xi Connaught Electrical Equipment Co. (www.hnxinuo.com) located in the south China city of Zhengzhou Area 6B 6B-3-342. Scraps and development in the wave of market economy, the current study Connaught Electrical and Mechanical has a high profile in the electronics, electrical products processing, enjoys a good reputation. Xi Connaught Electrical and Mechanical made whole network business alliance certification, marking our service and management level has reached a new height. Xi Connaught Electrical and Mechanical staff is willing to joint development with all people a better future.