PMSM Sensorless Vector Control Technology Hits The Target In The Invert Air-conditioner's Application Study

In this paper, a frequency control of motor speed principle of permanent magnet synchronous motor (PMSM) sensorless vector control technology was discussed. And PMSM sensorless vector control technology hits the target in the invert air-conditioner's application. The key of technology is to design position and speed observer. Then the position and speed was calculated, and current loop and speed loop were controlled. The sine wave current was output by the PMSM sensorless vector control technology. So the control of permanent magnet synchronous motor was completed. In addition to position and speed observer, static-dynamic performance of control system is decided by PI adjuster property of current and speed loop. There are many methods for engineering design of PI adjuster. A reliable and reasonable design method of PI adjuster was found in this work, and is easy to come true. So as to select key parameters, it lays foundation for the subsequent adjustment and optimization. Space vector pulse-width modulation (PWM) is a key component to realize sensorless vector control. The traditional space vector PWM algorithm is more complex. It will occupy more processor time and storage space to realize. It not allowed in demanded higher occasions such as real-time compressor driven. The traditional space pulse-width vector modulation method was simplified to accelerate PWM processing speed in order to improve the response speed of controller. A DC frequency compressor sensorless control rotor speed and position estimation method was made out in this paper. Meanwhile, the SVPWM algorithm of engineering realization method, engineering design method of DC frequency compressor closed-loop control speed loop PI regulator and current loop PI regulator, and the general formula of digital low-pass filter were deduced.It has been proposed that 32-bit MCU can realize the control technology of the implementation method in this work. Subsequently, the corresponding hardware design and software design were designed. The hardware design includes drive circuit, phase-current measure circuit, AC current and voltage detection circuit, etc. The software design includes coordinate transform, space vector modulation, PWM waves output, current detection and DC voltage detection, etc.Experimental results show that the PMSM sensorless vector control technology has achieved the expected goal. Under the experimental load conditions, frequency control can be controlled, and the voltage and current output waveform accord with theory analysis conclusions, and current output is three-phase symmetric sine wave, and rotate speed accords with control requirements. At the base of the work, we will optimize software and hardware of the system, improve the carrier frequency PWM output and improve performance of high and low frequency in the future. The performance of invert air-conditioner will has a big promotion to combine better control algorithm with better refrigeration system.