Abstract: With the development of power electronics technology， harmonic hazards has become increasingly serious， harmonic governance issues has been On the power source for electronic devices harmonic analysis and concluded that its harm and the corresponding harmonic management principles and comprehensive management， and management of a harmonic Key words: power electronics; harmonics; hazards; inhibition INTRODUCTION With the development of power electronics technology， power electronic devices to the extensive application of power system harmonics caused serious Various power electronic equipment in the transport， metallurgical， chemical and other industrial traffic the extensive application of harmonics in the grid problem is becoming increasingly serious， many low power factor of power electronic devices to the power grid additional burden on the quality of power and influence， Therefore， the power electronic devices harmonic pollution has become hinder the development of power electronics technology major Therefore， inhibition harmonic pollution and improve the power factor of power electronics technology has become a major issue in This paper focus on the key issues of power through electronic harmonic sources and the danger of understanding and analysis， and control of pollution from the relationship between the consideration of a comprehensive management approach on the final harmonic trends in the development of comprehensive management of the A power electronic device - the main source of harmonics Nonlinear load is a harmonic sources， which caused grid voltage distortion， in the voltage several times with the whole of the fundamental frequency Harmonic as the main source of power for various electronic devices mainly AC-DC converter (rectifiers， inverters， chopper， Drives)， as well as bidirectional thyristor controlled switching equipment， as well as internal power system Variable Flow equipment， such as HVDC rectifier valve and the valve， and other Below its harmonics generated an analysis of the 1 Rectifier As a DC power supply devices， rectifiers widely used in various Figure 1 (a) and Figure 1 (b) respectively for the single-phase and three-phase circuits In rectifier devices， AC power supply for the current rectangular wave， rectangular wave of the fundamental frequency for the current and Jibeiai several times for the high-frequency harmonic current waveform Obtained by Fourier series of rectangular wave of high harmonics In fundamental component I1 and the largest ratio of 1 / n， with the trigger control angle α， and the decrease of overlap angle μ for the increase of harmonic wave components have reduced In addition， the existing research results indicate that: Rectifier harmonic current operation mode of the size， has a direct impact， therefore consider adjusting the voltage and current rectifier， it is best to conduct overlap angle， as well as for harmonic phase pressure drop calculations， in order to determine safe and economical operation mode when the control close to 40 ° angle α， overlapping in the 8 ° angle μ about the circumstances are often the most serious state of harmonic， so to go through， as far as possible through the correct choice of regulating transformers tap in order to avoid Harmonic most serious point [1] 2 exchange regulator Exchange regulator used for lighting dimming and induction motor speed， and so Figure 2 (a) and 2 (b) respectively for the single-phase and three-phase circuits Exchange regulator and the harmonic frequency rectifier basically the Frequency Converter 3 Frequency converter is AC / AC Converter behalf of equipment， when used as motor speed control devices， which contain a change with the output frequency band edge， as for the frequency change， the more complicated harmonic Universal Converter 4 GM converter input circuits are all from the diode bridge rectifier and DC capacitor components in Figure 3 (a) shows， this circuit impedance input current waveform with the different big In the source impedance relatively small cases， the waveform for the lanky Zhaier high-waveform in Figure 3 (b) solid line shows the contrary， when the source impedance relatively large， its waveform for the dwarf and wide flat waveform Figure 3 (b) shown in dotted In addition to these typical converter will be a great number of harmonics， household appliances is not to be ignored harmonic Such as television sets， battery Although their individual capacity little， but because a lot of volume， they injected into the power supply system to the harmonic components can not be 2 harmonic hazards Harmonic hazards of the public network include: 1) make a public network components have additional harmonic loss and reduce the power generation， power transmission equipment efficiency， a large number of 3rd harmonic flow neutral line， the line will cause overheating or even a fire; 2) impact of the normal work of electrical equipment， in addition to additional wear and tear caused， and also enable a motor mechanical vibration， noise and over-voltage， transformer partial serious overheating， capacitors， cables and other equipment overheating， insulation aging， shortened life expectancy， resulting damage; 3) common cause in the local power grid and parallel resonant series resonance， so that harmonic magnification so that the aforementioned hazards greatly increase， or even lead to serious accidents; 4) will lead to protection and automatic device misoperation， and electrical measuring instrument measurement inaccurate; 5) to neighbouring interfere with communications systems， light， noise and lower the quality of communication， information led to heavy loss of the communications systems do not work 3 harmonic management principles To improve power quality， we must strengthen the management of the In restricted to the utility grid harmonic source harmonic current injection， will be allowed to limit the harmonic voltage within the scope of the First it is necessary to have systems in the harmonic sources and distribution， in the harmonic limit its scope in order to allow access， not curing the management measures must be taken to prevent the spread of For this reason the International Electrotechnical Commission (IEC) and the United States have recommended IEEE standards such as IEEE provisions of the current standard harmonic limits shown in Table China Power Grid with the actual level and the standard of other developed countries voltage distortion sine-rate provisions in table Table 1 harmonic current limits (IEEE519-1992 Provisions) Isc / IL H <11 11 35THD <> 0 Table 2 voltage distortion sine-rate limits Supply voltage / kV voltage distortion sine-rate limits / or 3856% 5 4 harmonic comprehensive management At present， China's electric power system harmonics on the management is "pollution first， treatment after" the passive situation，
