Research On Applications Of Pmsm Driven By The Inverter Without Electrolytic Capacitor

Because of the bigger capacity per unit volume and the lower price, the electrolytic capacitor is widely used in motor drive controller of the air conditioner. However, its use is influenced by the temperature, the current ripple and the working frequency, thereby limiting the service life of the machine and reducing the reliability of the circuit. Therefore, a study of motor drive controller scheme without electrolytic capacitor is of special significance.Firstly, this article expounds the basic principle, mathematical model and the typical control strategy of the permanent magnet synchronous motor. We analyzes the principle and characteristics of the traditional motor drive circuit and motor drive circuit with the PFC circuit, and based on the study of the new type of multiple motor driver circuit topologies, we study and analyze a new motor driver circuit topologies which can implement natural PFC function without electrolytic capacitor. We put forward the calculation method of apparent power for PMSM, give two kinds of control strategy: the inverter input current tracking method and the inverter input power tracking method, through the comparison and analysis, select the inverter input power tracing method for simulation, and verify the feasibility of this control strategy. In the view of the problem of the not high enough power factor and the relatively large amount of calculation of the algorithm while using the inverter input power tracing method, we put forward a new simplified control scheme. Based on the Freescale MC56F8335 DSP chip, we establish the hardware platform, combining with current loop of voltage feed forward and the sensorless technology based on the sliding mode observer, we carry on the experiment, and the experimental results verify the feasibility of this scheme.