Design Of Current Control System Research Articles

Hardware-in-the-Loop for Wind Energy Conversion with Resonant Current Control and Active Damping

In this paper, the design of current control system based on multiple resonant controllers with active damping control strategy for wind energy conversion system in Back-To-Back configuration with LCL filter is presented. Due to its ability to perform control and compensation of the injected currents into the network, the proposed system is a resonant current control (PR) and harmonic compensators (HC) of fifth and seventh order that allows the injection of currents with low harmonic distortion to the electrical network. The high frequency harmonics generated by the converter are damped by LCL filter. As a solution to the effects of the resonance frequency of the LCL filter, the active damping strategy is implemented. This improve the quality of current signal significantly, obtaining a THDi= 3.56\% and percentage level of each current harmonic lower than 2\%. The proposed control interacts in real time with the wind energy conversion system through the Hardware-in-the-Loop technique carried out in the Triphase PM5F60R, located in the microgrid laboratory of the University of Chile.

Coupling Analysis on Current Control at Low Switching Frequency for the Three-Phase PWM Converter Based on RGA and a Novel Output Feedback Decoupling Method

With the increase of the rated power, the sampling and switching frequencies of the high-power pulse-width-modulated (PWM) converter tend to be lower so that a challenging scenario is arising in current control system design. This strongly affects the stability and control performance of the current control system due to the undesirable dynamic coupling of the dq current components. From this perspective, this paper presents a systematic procedure for accurately evaluating the coupling of current control systems, which is based on static and dynamic relative gain array (static relative gain array and dynamic relative gain array). Unfortunately, the dynamic coupling of these systems is so serious at low-frequency band, and the parameter variation makes it easier for these systems to lose stability, when a classical proportional integral regulator with feed-forward decoupling or nondecoupling is employed. Hence, a novel output feedback decoupling control method is proposed, which is based on linear control for multiple-input-multiple-output system. Considering the amplification of the first-order differential, the decoupling unit is further improved by replacing the differential with high-pass filter. Experimental results in a small-power converter are presented to support the theoretical analysis and demonstrate the feasibility of the proposed method.

Adaptive fuzzy backstepping control of three-phase active power filter

A backstepping controller (BC) and an adaptive fuzzy backstepping controller (AFBC) are proposed for three-phase active power filter (APF) in this paper. Firstly, the dynamic model for APF is build in which both the system parameter variations and external disturbance are considered. Then, the backstepping method is applied in the design of current control system to deal with the nonlinearity of APF. Moreover, the AFBC is developed by combining the backstepping approach with adaptive fuzzy strategy to attenuate the effect of parameter uncertainties and external disturbances. Fuzzy logic system is designed to estimate the unknown nonlinear function in the AFBC where the parameters are adjusted online by the adaptive law derived from the Lyapunov stability analysis to guarantee the tracking performance and stability of the closed-loop system. Simulation studies using the MATLAB/SimPower Systems Toolbox demonstrate that the proposed control strategies exhibit excellent performance in both steady state and transient operation.

Systematic design of current control system for permanent magnet synchronous motors

This paper presents a systematic system design procedure of the current control system for permanent magnet synchronous machines (PMSM). Through the linear quadratic optimization design for the first order plus time delay plant controlled by a PI controller, a set of empirical formulas are found for the controller gains and the resulting closed-loop system characteristics. A systematic design procedure for the PMSM current control system is developed based on these empirical formulas, which results in a system design optimized for the chosen optimization criterion and yet with low hardware requirements including a low digital sampling rate and a low PWM update frequency.