PWM rectifier

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

Analysis and implementation of a three-level PWM rectifier/inverter

Abstract: A three-level pulse width modulation (PWM) technique for ac/dc/ac converter is proposed. Single-phase three-level rectifier based on double boost configuration with power factor correction is used in the input side. Three-phase three-level voltage source inverter based on diode clamped scheme is employed in order to reduce the harmonic content of the inverter output voltages. In the rectifier side, the hysteresis current controller is used to track the line current command in phase with the mains voltage. A capacitor voltage compensator is adopted to balance the neutral point voltage in order to maintain good quality voltage waveforms on the output of the inverter. In the inverter side, three-level PWM based on sine-triangular comparison is used to reduce the voltage harmonics. The major advantage of the adopted three-level scheme is that the blocking voltage of each power switch is clamping to half of dc-link voltage. The proposed control scheme is verified by the software simulation and experimental results based on a laboratory prototype.

A high performance DSP controller for three-phase PWM rectifiers with ultra low input current THD under unbalanced and distorted input voltage

Abstract: Although in recent years three-phase PWM rectifiers have become increasingly popular, in most practical cases the line unbalance and/or the presence of distortion can seriously affect their performances. Line unbalance and distortion add unwanted low frequency harmonics to the input current, leading to an increase in the total harmonic distortion (THD). At high power level, the switching frequency is restricted to a few kilo hertz and therefore an LC filter is needed to eliminate the switching ripple of the current. The resulting structure is an LCL filter that causes instabilities and oscillations. This paper details how to implement a high performance multi-loop digital controller suitable for a boost type PWM rectifier, leading to an extremely low THD content even with non-ideal input voltage conditions. The multi-loop method uses only two capacitor filter voltages and inverter currents to estimate the line voltages and currents. Positive and negative sequence controllers are used to regulate the fundamental currents while resonant controllers tuned to each harmonic from third to thirteenth remove the low frequency components due to input voltage unbalance and/or distortion. The proposed approach is implemented on a 16-bit fixed point DSP (ADMC401) and tested on a three-phase 20 kW IGBT-based PWM rectifier.

Network-Friendly Low-Switching-Frequency Multipulse High-Power Three-Level PWM Rectifier

Abstract: High-power converters for regenerative drives and distributed generation need a network-friendly operation, low harmonic conductive electromagnetic emission for low electromagnetic interference and high electromagnetic compatibility reaching high reliability and performance. Nevertheless, the converters must be controlled with low switching frequency in order to reduce the commutation losses. These two requirements can be satisfied if an optimal modulation strategy is used. The selective harmonic elimination (SHE) is one of the low-switching-frequency strategies most used today. However, this strategy only eliminates a reduced set of harmonic components from the input current. This paper presents a novel optimal modulation strategy whose objective is to reduce the total harmonic distortion of the input current. Six- and twelve-pulse three-level neutral-point-clamped pulsewidth modulation rectifiers are used in order to implement both modulation techniques. The results confirm the advantages of the proposed strategy, namely, less input current distortion and remarkable reduction of higher order harmonics compared with the SHE method, while keeping a low-switching behavior.

Minimum-loss PWM strategy for 3-phase PWM rectifier

Abstract: In this paper, the conduction and switching losses of a three-phase PWM rectifier are analyzed for various PWM schemes. On the basis of these results, a novel PWM strategy which minimizes the loss of a voltage-fed three-phase PWM rectifier is developed. This minimization results from the following two factors: (a) low switching frequency ratio; and (b) absence of switching in the vicinity of peak input current. The effectiveness of the proposed PWM strategy is verified by both simulation and experimental results.

Direct power control for three-phase PWM rectifier with active filtering function

Abstract: A novel virtual flux based direct power control space vector modulated (DPC-SVM) for 3-phase PWM rectifier with compensation of higher harmonics function is presented. The active and reactive power is used as a control variables for the PWM rectifier and active filtering operation. As a result several coordinate transformations are eliminated. Simulated and experimental steady state and dynamic performance for PWM rectifier and active filtering operation are presented. Among the main advantages of DPC-SVM are: simple algorithm, good dynamic and operation at constant switching frequency. Additionally a line voltage sensors were replaced by the virtual flux estimator which also help to achieve sinusoidal line current in case of distorted line voltage.