The Power Factor Correction Technology Research And Application Of Household Appliances

As the growing popularity of household appliances (refrigerators, air conditioning, and washing machine) in city and countryside, household appliances inventory of our country is huge. Household air conditioner reach200million.The power factor of household appliances is lower, generally only about0.7. So it reduced the capacity utilization rate of low voltage supply network, increased reactive power loss in power transmission.Using the power factor correction (PFC) can increase power factor, save energy and reduce the cost. Along with the fast calculation speed and cheap control chip to appear, accelerate the PFC technology to the intelligent and digitalization.The control strategy proposed in the paper is achieved base on control chip.Permanent magnet synchronous motor (PMSM) has the advantages of high efficiency, simple structure, reliable running etc., the driving control system has become more and more widely used in household electrical appliances. Aim at the characteristic of PMSM drive control system in household appliances, this paper design and exploit of double loop control circuit of Boost PFC control system. make a detail analysis of modeling process and the design of control loop circuit, establish voltage balance equation under a continuous current state, presents a given duty cycle of the voltage and current feedback control strategy of PFC. Use MATLAB/Simulink to simulate PMSM drive control system with PFC. The simulation results show that, Compared with the average current method, On the premise of guaranteeing the precision of control and maintaining stablity of the output voltage, can improve the response speed of the system. In the fluctuation situation of input voltage, motor torque and speed, the PFC control system still has good stability and high power factor.Make a detailed analysis of the control system; dissect the working principle and the way of realization of the main modules. Experiments were carried out on experimental platform, which STM32F103X (ARM) is chosen as the main controller, for verification. The results show that, under a fluctuation range of20%of the input voltage and different working frequency condition, the boost circuit PFC control system with double closed loop control strategy can maintain a stable output voltage, Ripple voltage is less than2%, Input current is of good sinusoidal waveform, Compare with traditional average current method, reduced the current distortion at the crossing point of voltage. The power factor is increased from0.98to more than0.995, it shows that the control strategy has good effect of power factor correction, has good application value to improve the power factor of the household appliances.