Tingjian Zhong

Bio: Tingjian Zhong is an academic researcher from Nanchang University. The author has contributed to research in topics: AC power & Volt-ampere. The author has an hindex of 1, co-authored 1 publications receiving 7 citations.

A new method for harmonic and reactive power compensation

Abstract: This paper presents a method for the harmonic and reactive power compensation with an adaptive hysteresis band current controller and a control algorithm for active power filter (APF) to eliminate the harmonics and compensate the reactive power in three-phase thyristor bridge rectifier. The adaptive hysteresis band current controller is adapted to the active power filter (APF). And it can change the hysteresis bandwidth according to modulation frequency, supply voltage, dc capacitor voltage and slope of the iC* reference compensator current wave. Until now, all of the studies have been carried out through detail digital dynamic simulation with the MATLAB Simulink Power System Toolbox. The results of simulation study of the new APF control technique and algorithm presented in this paper is found quite satisfactory in eliminating harmonics and reactive power components in utility current.

A novel hysteresis bandwidth (NHB) calculation to fix the switching frequency employed in active power filter

Abstract: Variable switching process is the main issue in practical implementation of fixed band hysteresis current controller in active power filters (APF) that increases the switching frequency and switching losses in power systems. Preventing this case, the Adaptive Hysteresis Current Control (AHCC) has been introduced and developed by many researchers. By this way, The Hysteresis Band (HB) will change adaptively by system parameters in order to control the switching speed and fix the switching frequency. In this paper a revisory method for the hysteresis bandwidth calculation procedure is proposed that makes switching frequency invariable significantly. The APF Simulations using proposed method (NHB) in Matlab/Simulink environment has been done. Results including switching frequency and current source TDH have been given to prove the efficiency of this method.

Current Control of the Isolated Self-Excited Induction Generator using Shunt Active Filter

Abstract: The Self Excited Induction Generator (SEIG) is an isolated power source whose terminal voltage and frequency are controlled by the excitation of the capacitance or the load impedance. This paper presents a method for calculating the minimum excitation capacitance using the equivalent circuit approach for analyzing the steady state operation of SEIG. A new strategy based on an active power filter (APF) for controlling the current and power quality of the self excited induction generator (SEIG) is also presented in this paper. The shunt active power filter was implemented using a three phase PWM current controlled voltage source inverter (VSI) and connected to the wind generator and loads in order to compensate the current harmonics and reactive power. The PWM-VSI gate control signals are derived from hysteresis band current controller. The proposed active filter proved to play an important role and give good dynamic response and robust behavior upon changes in load parameters. This investigation demonstrated that power average control strategy can facilitate the improvement of the power quality. The proposed control method extracts fundamental (reference) components of the source current for the shunt active power line conditioners for nonlinear and unbalanced loads. The Power average approach additionally maintains the voltage of the capacitor (of the PWM inverter) nearly constant without any external control circuit. The shunt APF in conjunction with the proposed controller performs perfectly under different steady state and transient conditions. The simulation results with nonlinear loads and unbalanced loads have showed the effectiveness of the proposed scheme for harmonic reduction in Wind based Power Generation.

Adaptive hysteresis band current control of grid connected PV inverter

Abstract: In this paper, adaptive hysteresis band current controller is implemented to control the current injected into the grid. Initially it was implemented by B.K Bose for control of the machine drive. Now it is implemented for the grid connected PV inverter, to control the current injected into Grid. It is well suitable for the distribution generation. The adaptive hysteresis band controller changes the bandwidth based on the modulating frequency, supply voltage, input DC voltage and slope of the reference current. Consequently, the controller generates pulses to the inverter. It is advantageous over the conventional hysteresis controller, as the switching frequency is maintained almost constant. Thereby quality of grid current is also improved. It is verified in time domain analysis of simulation using MATLAB.

Power Quality Compensation in Distribution System based on Instantaneous Power Theory and Recursive Fuzzy Proportional-Integral Controller

Abstract: In this paper, the power quality compensation problems such as current harmonics and system load's reactive power are considered. In this context, we use static distribution synchronous compensator to inject compensation current into the system, which its reference current signals have been derived from the instantaneous power theory. To improve the current control operation and fast tracking of reference signals, a PI recursive controller has been used which is able to reduce to zero tracking error compared to its conventional type. The performance of the controller is delayed for a period; to overcome this problem, the phase rules have been used to adjust the controller parameters to increase the control performance speed. Finally, in simulation we used Matlab / Simulink software, which has been proven to be better than conventional PI controller-based compensation for power quality.