Harmonic Current Suppression Method Based On Characteristic Of Inductance Storing Energy

With the development of power electronic technology, power electrical energy switching device has become the main harmonic source in power system. The existence of harmonic leads to poor power quality, influencing power system's safe and economical operation, and harming the security of power consumers' electrical equipment, and even affecting the development of national economy.The research has indicated that harmonic current produced by non-linear loads in today's power system is very easy to exceed the allowed value of harmonic current. therefore, this article proposes a harmonic current suppression method which can correct current waveform by inductance.The non-linear loads using power electronic switch conversion technology have be proved with time-varying characteristic and power conversion mechanism. Based on that, this article obtains the mechanism of harmonic current suppression that uses the magnetic field energy of inductance to offset the power of nonlinear loads, by analyzing the transition process of non-linear loads. Further more, the principle is applied to the stator windings of AC motor, and a new method of passive filtering by the three-phase mutual coupling inductance is formed. According to the theoretical derivation and analysis, the harmonic current suppression device based on the structure of motor is designed, and the physical experiments have been carried out to verify it's feasibility of harmonic current suppression.In the process of research, we find that the coupling between each phase of the harmonic current suppression device can effectively enhance the magnetic energy of each phase, so the device can better adapt to changes in non-linear load, and realize to the current waveform sinusoidal correction. Variety of conditions experimental results show that this harmonic current suppression device has constitute a energy transmission technology that provides distortion power to nonlinear loads by fundamental sine wave power, and has the current waveform correction function.In this paper, the harmonic isolation by magnetic energy is studied, and the current waveform sinusoidal correction without consuming the active power is realized. That is a passive filtering way of harmonic current suppression and is important for power system. The harmonic current suppression device is simple in structure, and easy to realize. It is easy extended to the HVDC project, frequency control device, and other fields. Therefore, the research ot this article has great scientific significance and the reference value of project application.