PWM rectifier

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

Sliding-Mode Observer Based Voltage-Sensorless Model Predictive Power Control of PWM Rectifier Under Unbalanced Grid Conditions

Abstract: A sliding-mode grid voltage observer (SMGVO) is proposed and experimentally verified in this paper for voltage-sensorless operation under an unbalanced network. The fundamental positive sequence component (FPSC) and fundamental negative sequence component (FNSC) are inherently separated in the observer without employing any additional filters. Due to embedded filtering effect, high frequency chattering and harmonic ripples can be well suppressed. Additionally, dc components can be completely rejected. As a result, dc offset would not cause fundamental frequency oscillations in magnitude and frequency of the estimated FPSC and FNSC. Owing to the predictive ability of SMGVO, one-step delay can be directly compensated using state variables in the observer. By combining estimation and prediction into one stage, the designed SMGVO turns out to be a compact solution for finite-control-set model predictive power control without voltage sensors. Theoretical proof is derived to verify that FPSC and FNSC can be accurately estimated and separated. Experimental results obtained from a two-level PWM rectifier confirm the effectiveness of the whole control system.

Control of Three-Phase, Four-Wire PWM Rectifier

Abstract: This paper presents the analysis, design, and control of a four-wire rectifier system using split-capacitor topology The proposed controller does not require any complex transformation or input voltage sensing A detailed analysis of the distortions in the line and the neutral currents is presented It is shown that the single-carrier-based, conventional sine-triangle PWM (CSPWM) scheme results in a peak-to-peak neutral current ripple, which is greater than the peak-to-peak ripple of any of the line currents Also, for the same operating condition, the distortions in the line and the neutral currents increase considerably, when a three-limb boost inductor is used instead of three single-phase inductors A three-carrier-based SPWM scheme is proposed in this paper Compared to CSPWM, the proposed scheme significantly reduces the neutral current ripple when three single-phase inductors are used, and reduces both line and neutral current ripples when a three-limb inductor is used The control scheme is verified through Matlab simulation It is implemented on an field-programmable gate-array (FPGA)-based digital controller and tested on a prototype Simulation and experimental results are presented

Advanced control scheme for a single-phase PWM rectifier in traction applications

Abstract: This work presents an advanced control scheme for a single-phase PWM rectifier. The controller consists of a PR (proportional-resonant) controller using the double sampling strategy, namely, a dual update scheme, a delayless feed-forward compensator, and a fast phase angle estimator. The PR controller is capable of regulating a sinusoidal line current without an additional prediction or an extremely high control gain under a medium switching frequency (0.5-5 kHz). The dual update scheme is the method that performs the sampling and control calculation twice in a switching period, which reduces the control time delay significantly and enables us to extend the maximum allowable control bandwidth. The proposed feed-forward compensator uses the estimated one-step predicted value of the source voltage and the source current to avoid adverse effects caused by the one-step delay, measurement noise, and harmonic component of the source voltage in the feedforward compensation process. A fast phase angle estimator is also presented, which is capable of estimating the phase angle and the frequency of the source voltage even under a highly distorted source voltage condition or a sudden amplitude, phase angle, or frequency changing condition. The feasibility of the proposed control scheme is confirmed by experiments.

EMI Filter Volume Minimization of a Three-Phase, Three-Level T-Type PWM Converter System

Abstract: In this study, the power density of a two-stage, i.e., LCLCL, electromagnetic interference (EMI) filter for a 10 kW three-phase, T-type three-level, boost-type PWM rectifier system is optimized concerning construction volume. It is found that reasonable boundary conditions limit or define most component values and only few degrees of freedom are remaining. In this context, the ratio of the first filter stage's common to differential mode inductance, k L = L cm,1 /L dm,1 , is identified to particularly affect the total filter volume. For given switching frequency and DC-link voltage of f s = 48 kHz and V dc = 700 V, a flat minimum of the overall filter volume results for 10 <; k L <; 40. The boxed volume of the filter realized for k L = 18 is 763 cm 3 (46.6 in 3 ), which corresponds to a filter power density of 13.1 kW / dm 3 (215 W / in 3 ). Measurements of conducted EMI confirm that the rectifier system complies with the considered limits of conducted EMI (CISPR 11, class A).