Vector Based Hysteresis Current Controller Research Articles

Space Vector-Based Hysteresis Current Controller of Asymmetrical Six-Phase Induction Motor

Space Vector-Based Hysteresis Current Controller of Asymmetrical Six-Phase Induction Motor

COMPARATIVE ANALYSIS OF UPQC WITH VARIOUS HYSTERESIS CURRENT CONTROLLERS

This paper deals the comparative analysis of a three-phase three wire Unified Power Quality Conditioner (UPQC) with various hysteresis current controllers. The UPQC is one among the custom power devices which is a integration of series and shunt active power filters (APF) connected by a common link capacitor. The construction of shunt and series APF is by using a three phase three wire Voltage source Inverter (VSI). In series active filter, synchronous reference frame technique is used to extract fundamental voltage; whereas in shunt active filters, instantaneous reactive power theory (IRPT) is used to extract fundamental current. Switching pulses for both filters generated by hysteresis current controller (HCC), multilevel vector based hysteresis current controller (MVHCC) and adaptive hysteresis current controller (AHCC).The performance of the various HCC based control algorithm of shunt active filter with series active filter is evaluated in a three-phase distribution system connected with non-linear and unbalanced load conditions. Fuzzy logic control is used for dc capacitance balancing. The control technique is executed by the use of MATLAB/Simulink-based simulations environment.

Analysis of three-phase PWM rectifiers using hysteresis current control techniques: a survey

The paper shows the survey of hysteresis current control technique for three-phase PWM converter numerous strategies: one of a kind in idea had described traditional HCC method, a new idea of online variant of this parabolic border, hexagonal and square hysteresis-based controls, quasi-fixed-frequency hysteresis current tracking control, a dead-beat adaptive HCC technique, vector-based hysteresis current control technique and proposed vector-based hysteresis current control technique are mentioned as well as the presentation which will illustrate properties of the described HCC technique.

Analysis of three-phase PWM rectifiers using hysteresis current control techniques: a survey

The paper shows the survey of hysteresis current control technique for three-phase PWM converter numerous strategies: one of a kind in idea had described traditional HCC method, a new idea of online variant of this parabolic border, hexagonal and square hysteresis-based controls, quasi-fixed-frequency hysteresis current tracking control, a dead-beat adaptive HCC technique, vector-based hysteresis current control technique and proposed vector-based hysteresis current control technique are mentioned as well as the presentation which will illustrate properties of the described HCC technique.

Investigations on Hysteresis-Based Current Control Techniques for Grid Connected Photovoltaic Systems

This paper focuses on delivering an effective performance qualification (PQ) control strategy for a grid connected photovoltaic (PV) system. A PV-based distributed generation system with a capacity of 10 kilo volt amps (kVA) was connected to the utility side of a power grid operating at 415 V. The power grid was modelled with a capacity of 100 kVA, 11 kV, and 100 km transmission line length. The PQ control strategy was implemented with three hysteresis-based current control techniques. To overcome the drawbacks of conventional hysteresis-control techniques, adaptive tuning of the hysteresis band was carried out, and a vector-based hysteresis current control is proposed to improve the results.

Hysteresis current controller for a general n ‐level inverter fed drive with online current error boundary computation and nearly constant switching frequency

A space vector-based hysteresis current controller for any general n-level three phase inverter fed induction motor drive is proposed in this study. It offers fast dynamics, inherent overload protection and low harmonic distortion for the phase voltages and currents. The controller performs online current error boundary calculations and a nearly constant switching frequency is obtained throughout the linear modulation range. The proposed scheme uses only the adjacent voltage vectors of the present sector, similar to space vector pulse-width modulation and exhibits fast dynamic behaviour under different transient conditions. The steps involved in the boundary calculation include the estimation of phase voltages from the current ripple, computation of switching time and voltage error vectors. Experimental results are given to show the performance of the drive at various speeds, effect of sudden change of the load, acceleration, speed reversal and validate the proposed advantages.

Design of D-STATCOM for Power Factor Correction in a Medium Transmission Line Using Vector Based Hysteresis Current Controller

The prime focus of this paper is on power factor improvement in a medium transmission line through reactive power compensation using the distribution side – Static Synchronous Compensator (D-STATCOM). A 100 kVA, 11 kV, 80 Km transmission line is taken into consideration and shunt compensation is established through the Vector based Hysteresis Current Control (HCC) technique. The purpose of implementing the vector-based HCC is to reduce the losses associated with a high switching frequency in the conventional HCC. The simulation results are presented to show the performance of the system and are found to be satisfactory.

Fault ride-through capability enhancement of doubly-fed induction wind generators

Recent fault ride-through (FRT) requirements have proven problematic for variable-speed wind generation systems. A particular problem regarding to doubly-fed induction generators (DFIGs) is that standard proportional integral (PI) current controllers, designed with very limited control bandwidth, cannot eliminate rotor current oscillations that occur during a grid fault. As a consequence, the current in the rotor-side converter can exceed the safety limits of semiconductor switches, which potentially leads to converter failure. This study introduces a hybrid current controller to enhance the FRT capability of DFIGs through keeping the rotor current below the safety limits. The proposed current controller includes two switching strategies: the standard PI current controller for normal operating conditions and a vector-based hysteresis current controller (with very fast transient response) for overcurrent protection during grid faults. Simulation studies are carried out to demonstrate the effectiveness of the proposed hybrid current controller under various symmetrical and asymmetrical voltage sag conditions.

A New Vector-Based Hysteresis Current Control Scheme for Three-Phase PWM Voltage-Source Inverters

This paper presents a new vector-based hysteresis current controller (HCC) for three-phase pulsewidth modulation (PWM) voltage-source inverters (VSI). The HCC is intrinsically robust to the load parameters variations, exhibits very fast transient performance, and is suitable for simple implementations. Despite these advantages, the conventional HCC has a major drawback when applied to the three-phase PWM-VSI: interphases dependency leads to very high-switching frequencies in the inverter. This paper starts with a review on the vector-based HCCs reported in the literature to address this problem. Then, a new vector-based method is proposed using multilevel hysteresis comparators integrated with a switching table. The proposed method works with the inverter current vector represented in the stationary α- β frame and produces a coordinated switching pattern. The current error is kept inside a square tolerance region without significant increase in the complexity of the hardware implementation. Simulation results show that the proposed vector-based method can retain the advantages of the conventional HCC. However, the steady-state performance of the proposed current regulator is significantly improved by reducing the switching frequency and minimizing oscillations of the inverter current vector. The proposed current controller is finally compared with other reported vector-based methods and its advantages are illustrated.

Implementation of Space Vector Based Hysteresis Current Control for a Three-Phase High Power Factor Converter

In this paper, an implementation of a space vector modulation (SVM) based hysteresis current controller (HCC) for the control of a three-phase high power factor rectifier is proposed. The SVM-based HCC scheme is designed, simulated and implemented. The technique combines the best features of the SVM and HCC techniques. The controller determines a set of state space vectors from a region detector and then applies a space vector selected according to HCC. A set of space vectors in a region, including the zero space vector for a reduced number of switchings, is determined from the output signals of three comparators with a hysteresis band a little larger than that of the main HCC. A simple experimental implementation is proposed and the simulation and experimental results of the SVM-based HCC are discussed in the paper.