PWM rectifier

About: PWM rectifier is a research topic. Over the lifetime, 2254 publications have been published within this topic receiving 25614 citations.

Electromagnetic-thermal coupled modelling and analysis of inter-turn short-circuit faults of a permanent magnet alternator

Abstract: This paper describes a computationally efficient model for predicting transient and steady-state behaviours of a permanent magnet alternator (PMA) connected to an asymmetric PWM rectifier and load in aerospace applications under healthy and fault conditions. The model is validated by finite element and circuit coupled co-simulation. The developed model is used to predict the PMA performance under fault conditions and to identify fault signatures that can be exploited for the development of fault detection techniques. The developed electric model is coupled to the thermal model to predict hotspot temperature of the winding under the worst case inter-turn short-circuit condition and to estimate the winding lifetime.

Control method for three-phase PWM rectifier suitable for power grid waveform distortion

Abstract: The invention discloses a control method for a three-phase PWM rectifier suitable for power grid waveform distortion. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion mainly includes that extracting a current reference signal under input voltage distortion and unbalanced disturbance, and actively injecting negative-sequence current, improved dead-beat inner current loop which is forecast through combining with linear extrapolation, and outer direct voltage loop performed with active disturbance rejection control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion plays roles of inhibiting the harmonic wave of the input current of the PWM rectifier, injecting proper negative-sequence current to eliminate the secondary power pulse of the output direct current voltage of the PWM rectifier, improving the transient response of the output direct current voltage, and compensating the influences of all kinds of delay on the dead-beat control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion is capable of obviously reducing the secondary wave of the output direct current voltage under the disturbance of the input harmonic wave and unbalanced voltage, improving the transient response speed of the PWM rectifier, reducing the transient offset of the direct current voltage, and improving the system control precision.

Unity Power Factor Operation of Three-Phase PWM Rectifier Based on Direct Power Control

Abstract: In this paper, direct power control (DPC) of three-phase PWM rectifiers is presented, without line voltage sensors. The controller builds upon the ideas of the well known direct torque control (DTC) for induction motors. In our case, the active and reactive powers replace the torque and flux amplitude used as controlled output in DTC. The instantaneous active and reactive powers, directly controlled by selecting the optimum state of the converter, are used as the PWM control variables instead of the phase line currents being used. The controller ensures a good regulation of the output voltage, and guarantees the power factor close to one. The proposed controller was tested both in simulation and experimentally. The results show the excellent performance of the proposed system such as a good dynamic behavior, a good rejection of impact load disturbance.

An on-line operated near unity power factor PWM rectifier with minimum control requirements

Abstract: Most PWM rectifiers use online PWM patterns which results in slow transient response. Damping resistors must be provided to avoid amplification of harmonics and current oscillations, especially during transient conditions. This results in reduced efficiency. In this paper, a current-source type PWM rectifier with online pattern generation and inherent pattern synchronization with the AC mains is proposed. The voltages across the input filter capacitors are chosen as the modulating signals. This results in a very fast starting and a much improved transient response. Also, the need of the damping resistors is eliminated due to the effective damping provided through the modulating of the capacitor voltages. Moreover, an additional phase-shifting circuit is added to the control scheme to achieve near unity power factor independent of the load variations. The paper includes analysis, design guidelines and experimental results on a 1 kVA laboratory prototype to confirm the theoretical considerations. >

DC voltage balancing control of half-bridge PWM inverter for linear compressor

Abstract: This paper proposes a new single phase back-to-back PWM converter for the power supply of the single phase by using both a full-bridge PWM rectifier and a half-bridge PWM inverter. In addition, the balancing control algorithm of DC voltage for this topology is also proposed by controlling the current of the half-bridge inverter. With the full-bridge PWM rectifier and the half-bridge PWM inverter, AC/DC/AC operation can be carried out by using only a six-pack power module and two series DC capacitors. Since two series connected capacitors are installed at the DC link, each capacitor voltage must be balanced for the safe operation. Using a IP(Integral-Proportional) controller, the DC voltage can be balanced without the current distortion. The proposed algorithm can be easily implemented without much computation and additional hardware circuit. The validity of the proposed algorithm is verified through simulations.