Active Power Filter Harmonic basic major hazards: ? Increase load power facilities, reduce system power factor, reducing the effective capacity and efficiency of power generation, transmission and electrical equipment, resulting in waste equipment, waste and electricity line losses; - cause no reactive compensation capacitor resonance and harmonic current amplification, resulting in a capacitor bank due to over-current or over-voltage is damaged or not in operation; · pulsating torque motor causes vibration, affect product quality and life of the motor; ? Since the eddy current and skin effect, motor, transformer, transmission lines and other produce additional power loss and overheating, waste of energy and accelerated aging of the insulation; · harmonic voltage proportional to its peak voltage in the form of enhanced electric field intensity sail Harmonic dielectric, reducing equipment life ; Zero sequence (3 multiple times) harmonic currents can cause neutral phase four-wire system overload and produce circulation Harmonic sold in the delta-connected transformer windings, the winding current exceeds the rated value, even when serious accidents. · Harmonics will change the operating characteristics of protection relays, malfunction protection facilities, such as automatic device operates on Protection disorder; · harmonic change the rate of change of change and peak voltage or current harmonic control program, delay the arc is extinguished, the impact of the circuit breaker breaking capacity; · make Metering especially induction meter produce measurement error; · interference from adjacent power electronics, industrial control equipment and communications equipment, affecting the normal operation of equipment. Looking to improve active filter active filter, on the one hand depends on the progress of components and integration technology, but it is also dependent on the circuit configuration and design innovation. Although RC active filter integrated energy mix, but fully integrated high quality RC active filter still unsolved. The main difficulty is not directly integrated precision resistive and capacitive elements on the chip, and a large share of the chip resistor and large capacitor area is too large. Switched capacitor filter to solve this problem opened the way to achieve a fully integrated; but it belongs to a discrete-time analog filters, and there is work to be improved and low frequency bands. An integrated filter to achieve precise resistance program is the use of linear MOS transistor (ie, unsaturated) zone to act as analog resistive characteristic, which is a voltage controlled by a gate voltage controlled resistance, it can be used off-chip (ie The chip away) reference value harmonic control, such as a crystal clock or an external RC components, with on-chip control circuit to precisely adjust the time constant of the circuit. This is a promising solution. There is also a composition with a transconductance operational amplifier (OTA) and capacitance C of the active filter, also promising a fully integrated solution. Harmonic sales, harmonic control, provided by the Henan Xi Xi Connaught Electrical and Mechanical and Electrical Equipment Co. Connaught. Henan Xi Connaught Electrical Equipment Co. (www.hnxinuo.com) strong, credible, in Zhengzhou, Henan electronics, electrical products processing industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead Connaught Electrical and Mechanical study into the brilliant and you work for a better future!