Dai Peng

An improved neutral-point-potential balance control strategy for three-level PWM rectifier

Neutral point potential balance control is very important to three-level neutral-point-clamped (NPC) rectifiers. In this paper, the balance control strategy is studied with three-level space vector pulse width modulation (SVPWM) algorithm based on reference voltage decomposition. An improved neutral-point potential balance control strategy based on balance factor is proposed and the principle is analyzed. Simulation and experimental results verify the validity of the control strategy.

Full digital control and application of high power synchronous motor drive with dual stator winding fed by cycloconverter

This paper presents air-gap flux-oriented vector control based on pseudo 12-pulse noncirculating current cycloconverter-fed dual stator winding synchronous motor (DSSM) drive for high power and low speed application. The dual stator winding salient pole synchronous motor with damper winding model is discussed. The feedforward decoupling control method and proportional-integral (PI) separate controller of stator current regulation has been used. The DSSM drive for mine hoist is implemented using a multiprocessor digital controller. Experimental results are presented.

Control of electrical excited synchronous machine at low switching frequency

The operation of the PWM converter should be kept at low switching frequency so as to restrain the dynamic losses of the three-level converter and improve its output power. However, traditional control methods are no longer suitable for this condition with the resulting increasing output harmonic distortion and reduction of dynamic performance. To overcome the above problems, a novel complex matrix model of the electrically excited synchronous machine combining the complex vector and matrix was established in this paper. And then, a hybrid observer was proposed to identify the instantaneous fundamental component of the stator current. With the consideration of the delay introduced by the switching device and the time-discrete sampling, a novel current control system was designed based on the control theory. MATLAB simulation and DSP experimental results verify the effectiveness of the proposed control method.