Simple Non-regenerative Deceleration Control of Permanent Magnetic Synchronous Motor for Vibration Control in Drum-type Washer/Dryer

Abstract

MemberDrum-type washer/dryers are becoming more common in Japan, but the vibration created by unequally distributed clothes is a significant problem in this type of machine. We have developed a vibration control that prevents this imbalance by re-arranging the balancer fluid on the opposite side of the heavier distribution when there is unequal distribution. The drum, which has a large inertia, must be decelerated rapidly to enable the balancer fluid to shift. When a permanent magnetic synchronous motor is decelerated using an inverter, the machine's energy is converted into electrical energy, which regenerates the power supply. A control method has been developed that adjusts the input power of the motor to zero, thereby eliminating the need for a discharge circuit. However, it is not easy to achieve this method with an inexpensive microcomputer.In this paper, a practical braking method in which energy does not regenerate the power supply is examined. First, a simple method in which non-regenerative braking is possible with low input power is proposed, even though the input power is not zero. The effectiveness of this non-regenerative deceleration control is verified by theoretical numerical analysis and by an experiment. The borderline of the voltage vector for the non-generative braking is affected by dead time, and the experimental results differ from the theoretically calculated results. However, it is experimentally confirmed that the proposed non-regenerative deceleration control can be achieved by correcting the impressed voltage vector based on experimental results. Finally, this control is applied to the vibration control of the drum-type washer/dryer, and it is confirmed that the balancer fluid moves as designed.

Trends of permanent‐magnet synchronous machine drives

“…Current sensorless-control systems are recently explored, which eliminates costly Hall-effect CTs instead of a magnetic-pole position sensor [17][18][19][20].…”

“…Y. Tomigashi et al presented a practical current-phase control method of a PMSM with a low-resolution position sensor, which allows sinusoidal current drive without current sensors [17][18]. The method features indirect d-axis current control incorporating a field-weakening function with no rotational coordinate transformation as indicated by the following equations:…”