Ma Ruiqing

The balanced current control of dual-redundancy permanent magnetic brushless DC motor

The main purpose of this paper is the method study of balanced current control of dual-redundancy permanent magnetic brushless DC motor (BLDCM), which is used in the electromechanical actuator system of aircraft. The cause and consequence of unbalanced current in the winding of dual-redundancy motor under simultaneous operation station are deeply analyzed. The dynamic mathematic model of dual-redundancy BLDCM is built, in which the mutual induction between every phases in dual-redundancy windings are considered. The balanced control of current is realized by using the method of crossed-compare each other of dual-redundancy current. The implementation of the basic control circuits of the balanced current is introduced. The simulation results and the experimental data of system show the validity of this method. It can realize the balanced current in windings of the brushless DC motor, and can also control the dual-redundancy motor to output equal torque at the same time.

A Novel Soft Switching Inverter for BLDCM EV Propulsion System

A novel zero voltage transition (ZVT) parallel resonant DC link voltage source inverter (VSI) is proposed for brushless DC machine (BLDCM) electric vehicle (EV) propulsion system. The presented soft-switching inverter is constructed from the conventional one by simply augmenting auxiliary resonant DC link, and the soft switching is easily achieved by suitable controlling of the auxiliary switch. The zero voltage switching (ZVS) operation for all switching devices in inverter has been achieved both for motoring and braking state. The DC link voltage is clamped to power voltage. Control of resonance is based on time sequence without testing any current or voltage, so pulse width modulation (PWM) control is simple. The operation principle and control scheme of inverter are analyzed. Computer simulation results reveal good performance.

Novel high accuracy full digital servo system

This paper introduces a novel full digital high accuracy super low speed servo system based on a high performance microcontroller. The authors expound and analyze the constitution, principle and features of the system. They research the control rule and function realization of the system. Experimental result show that the system has high accuracy and excellent super-low-speed characteristics.