Research And Development Of Low-cost General-purpose Inverters

This paper presents a new low-cost general inverter fully based on hardware,discusses the theory of cootrol strategy in detaiI, and outlines aIl system circuits.The controlling method of this device is based OI1 the best Space Vector PWM(SVPWM) strategy. ln comparisol1 with tl1e normal SPWM strategy, the advantage of thismethod lies on the simplicity of its calculatio11 and convenient control. ln addition, itsharmonic component (current distortions) a11d torque ripples are minimized.The PWM pattern gel1eration and tl1e systeln controI of the invertcr are implementedby EPlD. Fast speed, high reliability al1d ease of develop1nent are the advantages of EPlDwhich make the fuIly hardware-based invertcr successful.The nlain circuit consists of an AC-DC-AC voltage VVVF device. The inverter islnade up of six IGBTS that are driven by II12l30. TI1us, the structure of the circuit is greatlysimplified and the switching frequency is higher tl1an that of other inverters.The principled sample developed has achieved all the guide lines in the rougl1.