V/f control of permanent magnet synchronous motors suitable for home appliances by DC-link peak current control method

This paper presents a sensorless sinusoidal driving method of permanent magnet synchronous motors (PMSMs) for fans and pumps by V/f control. The proposed method is a simple method that controls DC-link peak currents by a single shunt resistor and a peak detector. Due to the damping factor from the square torque load characteristics of fans and pumps, the drives of PMSMs for fans and pumps by V/f control can be stabilized at starting and steady state. In general, pressure losses of the fluid pass of fan and pump systems are nearly constant; therefore, the flow rate and motor torque are determined by revolutions. Accordingly, high efficiency driving is possible by setting the reference currents corresponding to the q-axis currents at target revolutions. Because of the simple and low cost sensorless control, the proposed method is suitable for fan and pump motor driving systems of home appliances.