Research On PMSM Sensorless Speed Regulation System For Inverter Air Conditioner

In recent years the inverter air-conditioner with inductance motor has become a mainstream product, which has good performance and highly efficiency. But its has the disadvantages such as bigger start-up current and lower power factor. PMSM applyed inverter air-condition compressor will become the focus of research. Because its has higher powe factor, running efficiency and no excitation, so its can save more energy. In the process of PMSM vector control, we need detect the accurate position of rotor. But the PMSM is sealed in the compressor ,which is full of high-temperature high-pressed corrosive. So we can't use a mechanical sensor to get rotor's position. Therefore it's very important to find a simpler and reliable sensorless control method.This paper focuses on sensorless PMSM vector control applied to air-conditioner compressor. Derived in two rotor's position estimation technique such as sliding mode observer (SMO) and full order state observer, which besed on back-EMF estimation. The problems of observers were deeply study.First, Improve and extend traditional SMO, variation gain, Sigmoid function and back-EMF adaptive filter were used to resolved high frequency chattering issue for SMO. At the same tine, the stator resistance online identification is joined in SMO improve estimation accuracy of rotor's position and system robustness. In addition During construction of full order state observer, regardless of motor's mechanical equation, avoid the impact of uncertain parameters such as inertia.Second, use the PLL technique after EMF estimated by observers, which reduce the calculation error. And use PDFF speed regulator to reduce the speed fluctuation, that is caused by lode change of compressor. In addition, apply for the method of pre-position open-loop starting to resolve the problem of starting for PMSM sensorless control.Finally, make simulation analysis for static/dynamic performance and robustness of PMSM sensorless vector control based on observers. In addition, design the hardware circuit and write DSP software programs for controller system of air-condition compressor with PMSM. At the same time make a experiments on improved extended SMO in this experiment platform,and deeply analyze running performance of PMSM by experiment, that is used in the air-condition compressor.