Bio: M.-S. Liao is an academic researcher from National Yunlin University of Science and Technology. The author has contributed to research in topics: AC power & Volt-ampere. The author has an hindex of 1, co-authored 1 publications receiving 18 citations.
••01 May 2001
TL;DR: In this paper, the switching mode rectifier is employed to work simultaneously as a power factor corrector and an active power filter, to decrease current harmonics drawn from a nonlinear load.
Abstract: Active power filters are an important means to increase power quality, due to wide use of nonlinear loads and switching mode power converters. The paper presents a simple control strategy which has employed the switching mode rectifier to work simultaneously as a power factor corrector and an active power filter, to decrease current harmonics drawn from a nonlinear load. As no additional active power filter is needed, the cost of this configuration is lower than that of the conventional active power filter configuration. A sliding mode controller is used in the current control loop to achieve fast dynamics. Only the source currents have been measured in the proposed control scheme to reduce the elements of current sensors needed in the conventional control approach. A simple proportional-integral controller is adopted in the voltage control loop to achieve slow dynamics. The proposed scheme can achieve high power factor, current harmonic elimination and no dedicated active power filter. A diode rectifier feeds the capacitive load as the nonlinear load is taken on AC mains to demonstrate the effectiveness of the proposed active rectifier for reactive power and current harmonic compensation.
••08 Jul 2003
TL;DR: In this paper, a modified hysteresis current controller for the control of a PWM rectifier is presented, where the controller parameters are designed in the discrete-time domain.
Abstract: A modified hysteresis current controller for the control of a PWM rectifier is presented. Mathematical modelling and control of the PWM rectifier is described. Controller parameters are designed in the discrete-time domain. A comparison study between a conventional hysteresis current controller and the modified hysteresis current controller is presented. Various simulation results are obtained and verified experimentally.
••01 Dec 2006
TL;DR: Passivity-based sliding mode (PBSM) approach has been used on designing static synchronous compensator (STATCOM) controller aimed at reactive power compensation and voltage regulation.
Abstract: The Passivity-Based Sliding Mode (PBSM) approach has been used on designing Static Synchronous COM-pensator (STATCOM) controller aimed at reactive power compensation and voltage regulation. The energy-dissipative properties of the proposed model derived in the synchronous d-q rotating frame are fully retained. The proposed controller design is separated into the inner loop and the outer loop controller. In the inner loop, passivity-based control is employed by using energy shaping and damping injection techniques to produce the proper switching function for Voltage Source Converter (VSC)-based STATOCM. The load terminal voltage and the DC-side voltage dynamics are regulated via the outer loop controller cascaded to the inner loop controller. The outer loop control is employed by two sliding mode controllers to determine the appropriate current command. Simulation results are presented to show efficacy of the resulting PBSM controller with regard to voltage regulation and reactive power compensation.
01 Jan 2005
TL;DR: The simulations and experimental results are presented which show the performance of proposed estimator and predictor of grid emf and its influence on operation of the control system of PWM rectifier with active filtering.
Abstract: Control of PWM rectifier with active filtering is realized by fast and precise shaping of its AC currents. In the paper the control system with predictive algorithms of both set currents calculation and currents control is proposed. These algorithms provide very high accuracy and dynamics of AC currents shaping which is limited only by parameters of the power circuits. In both algorithms calculations are based on precise information about present and future samples of in general distorted and unbalanced equivalent electromotive force (emf) of the grid. For this purpose the novel, grid voltages sensorless, precise estimator and predictor of grid emf is proposed. This robust algorithm is based on digital signal processing techniques and requires relatively low computational effort. In this paper the simulations and experimental results are presented which show the performance of proposed estimator and predictor of grid emf and its influence on operation of the control system of PWM rectifier with active filtering
01 Jun 2005
TL;DR: The paper presents structure and experimental results of control system of the PWM rectifier with active filtering function and proposes a novel estimator and predictor for both control as well as calculation of grid currents.
Abstract: The paper presents structure and experimental results of control system of the PWM rectifier with active filtering function. Proposed control system was designed for maximum filtering performance in steady state. This task is realized by predictive algorithms applied for both control as well as calculation of grid currents. Accuracy of these algorithms strongly depends on precise information about future samples of equivalent electromotive force of the grid, which is in general distorted and unbalanced. For this purpose, a novel estimator and predictor is proposed. The control of DC voltage is realized with application of variable gain PI controller. It ensures high dynamics in transient states and low gain for steady state oscillations of DC voltage. Proposed control system is AC voltages sensorless and has excellent active filtering performance, even at presence of grid voltage distortions. power quality, PWM rectifier, active filter, predictive control
22 Apr 2007
TL;DR: In this paper, a multi-loop dynamic error driven controller based on the decoupled voltage and current tracking loops for modulating the static synchronous compensator (STATCOM) used in distribution networks with dispersed renewable wind energy generation is presented.
Abstract: This paper presents a novel multi-loop dynamic error driven controller based on the decoupled (d-q) voltage and current tracking loops for modulating the static synchronous compensator (STATCOM) used in distribution networks with dispersed renewable wind energy generation. The multi loop regulator adjusts the pulse switching pattern of the voltage-sourced converter (VSC) to ensure effective reactive power compensation and harmonic reduction. The effectiveness of the controller is fully validated under different operating conditions, like load switching and wind velocity excursions.