Adaptive Hysteresis Current Control Research Articles

Design and Implementation of Hybrid Controller for Dynamic Power Management in a DC Microgrid

Nowadays more and more devices and appliances are operated with electricity, thus the electrical crisis is increasing exponentially day by day. In order to avoid the occurrence of electricity crisis, various power generation resources are used at the utility side to enhance the power generation to meet the consumers’ demand for electricity. Hence, a suitable control scheme has to be implemented at the microgrid to reduce the electrical fluctuation, power loss and manage the power quality. The Adaptive Proportional Integral Voltage Controller (APIVC) and hysteresis current controller (HCC) are integrated to enhance the quality of power generated. The electrical fluctuation is reduced by the proposed efficient hybrid parallel source controller model for DC Microgrid. The proposed model exerts decentralized control, which is an advanced droop control where communication is not required. The outer voltage control loop and inner current control loop provide faster control to maintain the grid voltage constant. The grid voltage is set as the reference value and the actual value is sensed to generate error value, which sets the reference value of current. The error signal is processed to provide switching signals for the converters. The performance analysis and simulation results show that the proposed mechanism performed better than the conventional methods such as Hysteresis Band Current Controller (HBCC) with Pulse Width Modulation (PWM) and Proportional Integral Voltage Controller (PIVC) with Hysteresis Current Controller (HCC), in terms of the electrical fluctuation, power loss and manage the power quality in the microgrid.

Harmonic Mitigation in a Hybrid Power System Integrated Shunt Active Power Filter Employing FLC and an Adaptive Current Control Technique

The main objective of this study is to mitigate current harmonic issues in hybrid renewable energy systems based on solar photovoltaic (SPV) and wind energy distribution. This is achieved with the help of a suitable controller-based shunt active power filter (SAPF). The SAPF is designed using a modified synchronous reference frame (MSRF) to reference current generation, an adaptive hysteresis current controller (AHCC) for switching pulse generation, and a fuzzy logic controller (FLC) for DC-link voltage regulation. The results of the proposed SAPF model developed in MATLAB/Simulink, show that the filter performs remarkably well in suppressing harmonics under different loading conditions. It is capable of fast corrective action under dynamic conditions and outperforms previous methods in terms of harmonic mitigation and dc-link voltage stabilization. The control techniques are compared on the basis of parameters such as harmonic compensation and dc-link voltage ripple reduction capability under changing load conditions. The results obtained through simulation represent the validity of the filter performance.

Shunt active power filter with MSRF-PI-AHCC technique for harmonics mitigation in a hybrid energy system under load changing condition

ABSTRACT In this study, a shunt active power filter (SAPF) is used to measure the harmonics level of a hybrid power system based on solar PV (SPV) and wind system. The SAPF employs a modified synchronous reference frame technology, an adaptive hysteresis current controller method, and a conventional proportional and integral based voltage regulator for the generation of reference current. The recommended SAPF performs extremely well in suppressing harmonics under varied load and source conditions. The results show that the proposed model outperforms earlier approaches in terms of harmonic mitigation and dc-link voltage stability. It was created in MATLAB/Simulink. The SAPF can minimise harmonics of the source current from 26.74% to 1.565% and 20.25% to 1.80% for inductive and capacitive load case respectively under ideal source condition and 30.05% to 3.82% (inductive) and 25.25% to 3.56% (capacitive) under non-ideal source condition. The proposed controller also reduces the ripples from the dc-link capacitor voltage from 22 V to 8 V and 9 V under both the source condition, respectively, based on the numerical comparison of findings.

Microgrid Power Quality Improvement Using Active Power Conditioner

This paper discusses power system power quality issues and possible remedies using power electronics. Several worldwide standards This research shows how a Shunt active power filter can improve power quality in a microgrid system at the distribution level. The major goal of this study is to find an appropriate pulse generating strategy for improving the shunt active power filter's compensation capabilities. The device's compensating capability is mostly determined by the DC link capacitor voltage regulation. A fixed hysteresis current control approach has been employed in the past. An adaptive hysteresis current control technique has been developed here to improve the performance of a shunt active power filter. The suggested technique's performance has been verified in the MA TLAB/SIMULINK model platform under various operating conditions.

A Power Control Method for Hybrid Electrical Accommodation Systems

This paper presents a power control method for a hybrid electrical system, which enhances a conventional main AC grid by adding a DC sub-grid in parallel. In this system, each prosumer connects to the sub-grid via a couple of half-bridge inverters of a device called a power router. All of the power routers connected to the sub-grid are controlled such that they maintain the voltage of the sub-grid equally, which is an essential feature of peer-to-peer power accommodation without synchronization. This paper proposes an adaptive hysteresis current-control technique for controlling sub-grid-connected inverters that maintains the voltage of the sub-grid while accommodating a given power. The proposed control method also balances currents between positive and negative lines of the sub-grid simultaneously. The proposed control method is implemented on a high-speed FPGA-based digital controller and is evaluated on three prototypes of the power router. The experimental results show that the proposed method yields fast and stable responses and enables the power router to accommodate power with a high accuracy.

LVRT capability enhancement in the grid-connected DFIG-driven WECS using adaptive hysteresis current controller

LVRT capability enhancement in the grid-connected DFIG-driven WECS using adaptive hysteresis current controller

A novel common‐ground switched‐capacitor five‐level inverter with adaptive hysteresis current control for grid‐connected applications

The aim of this paper is to present a new topology of single-phase transformerless inverters, which can be tied to the local grid as a low-scaled ac module system. The proposed topology offers a common ground between the neutral point of the ac grid and the negative terminal of the dc supply, and can properly alleviate the concern of variable common mode voltage and leakage current problems. This promising feature is acquired by the aim of both the switched-capacitor and charge pumped circuit cells. In order to inject a tightly controlled ac current to the grid, an adaptive hysteresis current controller scheme is also presented, which can guarantee almost fixed switching frequency operation of the involved power switches. A complete theoretical analysis, comparative study, and the relevant experimental results are also given to confirm the superior performance of the proposed topology.

Optimal Real Power Penetration to Solar PV-Fed Double Boost Integrated Multilevel Converter with Improved Power Quality

In grid-connected solar PV system, power quality gets affected seriously due to the variable real power penetration. The transformer is mandatory to integrate and isolate the solar PV and powered network. However, due to presence of this transformer, size and cost of the entire solar PV station get increased and it requires more space while supplying poor quality of power. In order to overcome this drawback, this paper proposes a double boost integrated multilevel inverter to inject the power into utility grid. In addition, the optimal control strategy is used to tap maximum power generation from solar PV and injected into grid with improved power quality. This paper presents an adaptive digital hysteresis current control approach to penetrate optimal power into grid. To validate the proposed work, the simulation results are carried out using PSCAD/EMDTC software. Furthermore, to confirm theoretical study and simulation study, the experimental test was performed and detailed results with validation were presented in this paper.

Adaptive fuzzy controlled hybrid shunt active power filter for power quality enhancement

A novel switching pulse generation methodology based on adaptive fuzzy hysteresis current controlled hybrid shunt active power filter (A-F-HCC-HSAPF) is presented in this paper for compensating reactive power and harmonics in distribution network. The harmonic problems are mainly evolved because of extensive use of nonlinear loads in industry and domestic sectors. There are some adverse effects of harmonics such as: malfunctioning of sensitive equipment, resonance issues, conductors heating, power losses and reduced efficiency in distribution system. To mitigate harmonics issues passive, filters are used but when the harmonic component increases the design of passive filters is complex and becomes bulky. With the advancement in power electronic, the active power filter has been designed. Generally, the rating of the active filter is very high for some applications; hence hybrid shunt active power filter (HSAPF) is proposed by low-rated shunt active power filter (SAPF) and low-cost shunt passive filter. Proportional-integral or fuzzy logic controller is used to estimate the reference current and to regulate the dc capacitor voltage. To generate the switching pulse for the voltage source inverter of the SAPF, a novel adaptive fuzzy hysteresis current controller (A-F-HCC) is adopted. The performance of the proposed A-F-HCC-HSAPF is investigated during steady-state and transient conditions using MATLAB/Simulink and real-time environments.

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.

Active power filter using a novel adaptive fuzzy hysteresis current controller

This paper presents a shunt active power filter (APF) for mitigating harmonics and reactive-power compensation in the distribution system. The compensation process is based on modified-synchronous reference frame (modified-SRF) control strategy that is different from conventional-SRF method. A simple and efficient unit vector calculation is used in the proposed modified-SRF in lieu of phase locked loop for vector orientation that cancels the presence of harmonics and notches in the distribution system. The shunt active power filter is implemented with voltage source inverter (VSI) and its switching pulses are generated through a novel adaptive-fuzzy-hysteresis current controller (HCC). The adaptive-fuzzy-HCC calculates the hysteresis bandwidth effectively with the help of fuzzy logic controller (FLC). This method reduces the switching power losses and improves the VSI performances for active filter substantially compared to fixed-HCC and adaptive-HCC. The shunt active filter system is validated through extensive simulation under both steady-state and transient conditions with different nonlinear loads. Comparative assessments of conventional-SRF and modified-SRF reference current generator methods are carried out.

Active power filter using a novel adaptive fuzzy hysteresis current controller

Active power filter using a novel adaptive fuzzy hysteresis current controller

Realisation of Adaptive Hysteresis Current Controller for Performance Improvement of Vector Control Based IPMSM Drive System

AbstractThe torque ripple, current fluctuation and variable switching frequency of conventional hysteresis current controller (CHCC) under different loading condition and motion variation is inevitable, which demands effective implementation of the existing current controller by which it will be possible to get rid of these limitations. This paper presents enhancement in performance of a vector controlled based Interior Permanent Magnet Synchronous Motor (IPMSM) drive system by using an adaptive hysteresis current controller (AHCC). This controller minimizes torque ripple, current error and is capable of providing nearly constant switching frequency by modifying its bandwidth according to the changes in the system parameter or when the system is subjected to any kind of disturbances and load variation. Initially the study is carried out in MATLAB-Simulink environment and then the test result is experimentally validated through hardware implementation with the help of DSP TMS320F2812 which provides a complete digital control system with high effectiveness and fast computational skill.

Digital Adaptive Hysteresis Current Control for Multi-Functional Inverters

This paper proposes a digital adaptive hysteresis current control method for multi-functional inverters in a power-flow control device called digital grid router. Each inverter can be controlled in master, grid-connected, or stand-alone modes, which can be specified by the controller. While the popular linear sine-triangle pulse width modulation (SPWM) control technique requires complicated proportional-integral (PI) regulators with an unavoidable time delay, hysteresis current control has a simple structure, fast responses, and robustness due to its independent system of parameters. Since the hysteresis current control method controls the output current stay around the reference current directly, in the multi-functional inverter, the reference output is not given by a current directly. Thus, the reference current used to implement the hysteresis current control in this study is calculated from the given reference voltage or power in each control mode. The controller uses high-speed sampled data at MHz level and is implemented by using a field-programmable gate array (FPGA). Experimental results show good performances of the proposed controller in controlling power exchanges in the digital grid router.

MPPT and SPPT Control for PV-Connected Inverters Using Digital Adaptive Hysteresis Current Control

Most PV systems are usually controlled by a Maximum Power Point Tracking (MPPT) algorithm to maximize the generated electrical power. However, the maximum power is often unstable and depends on the solar irradiance and temperature. This makes it difficult to control the power grid supply-demand balance due to fluctuations caused by the increase of renewable and variable PV systems. This paper proposes a new control algorithm for a PV-connected inverter called Specified Power Point Tracking (SPPT) control in addition to the conventional Maximum Power Point Tracking (MPPT) control. The PV system is controlled to generate the maximum power or a specified power depending on the electricity transactions comes from the electricity trading system. A high-speed FPGA-based digital adaptive hysteresis current control method, which has fast and stable response and simple structure comparing with the popular Sine-triangle Pulse Width Modulation (SPWM) method, is proposed to implement the MPPT and SPPT control. The adaptive hysteresis current band is calculated adaptively to improve a disadvantage of the classical fixed band hysteresis current control on the varying switching frequency. A reference current used in the adaptive hysteresis current control is calculated such that the output power of the PV-connected inverter is maximized in the MPPT control or is maintained at a given value in the SPPT control. The experimental and simulation results show that the PV-connected inverter under the proposed control algorithm generates the desired power almost exactly and yields stable and fast response despite the varying irradiance.

Adaptive hysteresis based multifunctional electric vehicle charger with a single feedback loop controller

The electric vehicles (EVs) have gained popularity over recent years due to the stringent environmental standards on greenhouse emission and the scarcity of fossil fuels. The increased demand for plug in EVs has necessitated grid integrated bidirectional EV battery charging systems. These charging stations deployed near the parking lots, shopping malls or industries can make the EVs suitable for long-distance runs. Moreover, the off-board charging methods with grid integration and proper communication interfaces can utilise the EV to enhance demand side management. This study proposes a multifunctional, grid integrated, bidirectional charger with a single feedback loop controller. Along with the battery charge or discharge control at unity power factor operation, the system can act as an active power filter for the non-linear and reactive loads connected to the point of common coupling. Also, the bidirectional AC/DC converter is operated with reduced switching adaptive hysteresis current controller to assure high efficiency. Analysis of various modes of operation of the system is done using MATLAB/Simulink and the prototype of the low power setup is done with FPGA to validate the concepts.

Real Time Harmonic Mitigation Using Fuzzy Based Highly Reliable Three Dual-Buck Full-Bridge APF for Dynamic Unbalanced Load

Abstract This study presents a highly reliable 3-phase 4-wire, three dual-buck full-bridge shunt active power filter (3 DB FB APF) for distribution system. The proposed topology uses three single phase dual buck full bridge inverter sharing the same dc-link capacitor with high utilization of dc-bus voltage. The dual buck inverter circuit composed of one power switch and one diode leg instead of two power switches conventional inverter leg effectually eliminate the undesirable “shoot-through” phenomenon occurs in conventional inverter circuit. The fuzzy and adaptive hysteresis current controller based id-iq control strategy has been adopted to generate optimized switching frequency. For validation, the proposed topology is implemented in the OPAL-RT LAB using OP5142-Spartan 3 FPGA. The dynamic performance of the proposed 3 DB FB APF is assessed for sinusoidal, unbalanced and non-sinusoidal voltage source condition with unbalanced non-linear load that is when both three-phase and single-phase loads are present in the system. Besides, the results with proportional-integral (PI) controller are compared with FLC in terms of harmonic compensation. Furthermore, a comparison has been made between split capacitor dual buck half bridge active power filter (2C DB HB APF) and proposed 3 DB FB APF based on switch power rating.

Active Power Sharing and Reactive Power Compensation in a Grid-tied Photovoltaic System

In the present scenario of energy crisis, researches on non-conventional energy sources have grown appreciably. The electrical energy derived from the PV panel is considered as the most useful natural resources. This paper deals with the operation and control of a grid interfaced PV system. Inverter control is achieved by using adaptive hysteresis current control scheme. The proposed inverter control technique interfaces renewable energy source and the AC bus of micro grid. It provides the possibility of injecting power from the renewable sources and favours reactive power compensation. The resulting controller is simulated in MATLAB/SIMULINK and results are analyzed.

A Digital Hysteresis Current Control for Half-Bridge Inverters with Constrained Switching Frequency

This paper proposes a new robustly adaptive hysteresis current digital control algorithm for half-bridge inverters, which plays an important role in electric power, and in various applications in electronic systems. The proposed control algorithm is assumed to be implemented on a high-speed Field Programmable Gate Array (FPGA) circuit, using measured data with high sampling frequency. The hysteresis current band is computed in each switching modulation period based on both the current error and the negative half switching period during the previous modulation period, in addition to the conventionally used voltages measured at computation instants. The proposed control algorithm is derived by solving the optimization problem—where the switching frequency is always constrained at below the desired constant frequency—which is not guaranteed by the conventional method. The optimization problem also keeps the output current stable around the reference, and minimizes power loss. Simulation results show good performances of the proposed algorithm compared with the conventional one.

Improving the Dynamic Response during Field Weakening Control of IPMSM Drive System using Adaptive Hysteresis Current Control Technique

Abstract This paper presents the control of IPMSM drive in flux weakening region, for high speed applications. An adaptive hysteresis band current controller has been designed and implemented in this work to overcome the drawbacks which are present in case of conventional hysteresis band current controllers such as: high torque ripple, more current error, large variation in switching frequency etc. The proposed current controller is a hysteresis controller in which the hysteresis band is programmed as a function of variation of motor speed and load current. Any variation in those parameters causes an appropriate change in the band which in turns reduces the torque ripple as well as current error of the machine. The proposed scheme is modeled and tested in the MATLAB-Simulink environment for the effectiveness of the study. Further, the result is validated experimentally by using TMS320F2812 digital signal processor.