PWM rectifier

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

A novel adaptive sliding mode control of PWM rectifier under unbalanced grid voltage conditions based on direct power control

Abstract: To deal with the control problems of the three-phase PWM rectifier under the unbalanced grid voltage conditions, this paper proposes a modified direct power control strategy using adaptive sliding mode control algorithm with model of the PWM rectifier in stationary αβ frame. The active and reactive power dynamics of the PWM rectifier are linearized and decoupled based on the inverse system algorithm. Then a sliding mode control scheme is designed to improve the robustness and reduce the influences caused by the system parameters variations and load disturbances. In order to satisfy the state requirements, an adaptive law is introduced to the control strategy to reduce the sliding mode control gain on the premise that the system is stable. Simulation results confirm the feasibility of the proposed control strategy.

An improved output short-circuit protection for multilevel PWM rectifier

Abstract: This paper describes an improved short-circuit protection method with a boost type rectifier using a multilevel AC/DC power converter. Since the output DC capacitors of the proposed scheme have ability to keep a floating state, the DC capacitors do not discharge even in case of short-circuit of a DC load. The output DC power of the proposed converter can be disconnected from the load within several hundred microseconds at the instant of short-circuit fault. Once the fault has been cleared the DC power is reapplied to the load. The rising time of the DC load voltage is as small as several hundred microseconds, and there is no overshoot of the DC voltage because the DC output capacitors hold undischarged state. Therefore, the proposed converter can be used for a power supply, which requires a rapid disconnection of the load from the power supply in the case of a short circuit, as well as a rapid connection the load to the power supply after the clearance of the short circuit condition. The converter, which employs the proposed method, has the characteristics of a simplified structure, reduced cost, weight, and volume compared with a conventional power supply, which has frequent output short-circuits. Experimental results are presented to verify the usefulness of the proposed converter.

Simulation of Three-Phase Voltage-Source PWM Rectifier with LCL Filter

Abstract: Three-phase voltage source PWM rectifier can attenuate high frequency harmonics effectively with LCL-filter which has the advantages such as smaller inductance and less output current’s THD in contrast with traditional L-filter, and suitable for medium and high power applications. In this paper, mathematical model of PWM rectifier with LCL-filter is analyzed and dual closed-loop control structure of inner current loop and outer voltage loop is designed, then the LCL-filter‘s parameters are analyzed and designed. At last, a simulation model of the rectifier is established; the simulation results show that the grid-side currents have lower harmonic distortions and the rectifier runs at high power factor, which verify the validity of the proposed method.

A half-bridge resonant inverter with three-phase PWM rectifier for induction heating

Abstract: A half-bridge resonant inverter with three-phase PWM rectifier for induction heating is proposed in this paper. An adjustable frequency limit is introduced to maintain the inverter's switching frequency at a value higher than the resonant frequency for zero voltage operation. In case of no work piece in the induction coil, the dc bus can be adjusted while the switching frequency of the inverter remains at the limit. The important advantages of the proposed system are reduced switching loss, small size of filter and faster response at a no load condition. The proposed technique is implemented on the created hardware setup. The inverter operates at in a frequency range of 20–40 kHz, while the three-phase PWM rectifier runs at 23.8 kHz to deliver output power at 1.5 kW.

Circuit for eliminating secondary ripple of single-phase PWM rectifier

Abstract: The utility model discloses a circuit for eliminating secondary ripple of a single-phase PWM rectifier, which comprises an alternating-current side, a converter and a direct-current side, wherein the alternating-current side is connected with the converter through an inductor, the other side of the converter is connected with the direct-current side, a capacitor C2 is connected between the input end of the alternating-current side and a negative electrode end of the direct-current side, and a capacitor C1 is connected between the input end of the alternating-current side and a positive electrode end of the direct-current side. Compared with an original H-bridge converter, the circuit provided by the utility model divides filter inductance at the alternating-current side into two parts, and a capacitance bridge arm is additionally arranged, thereby not only being used for absorbing power of the secondary ripple, but also playing a role of supporting direct-current bus voltage, and achieving purposes of reducing the secondary ripple at the direct-current side and replacing a large capacitor at the direct-current side.