A new control technique to enhance the stability of a DC microgrid and to reduce battery current ripple during the charging of plug-in electric vehicles

The AC power system is leading due to its established standards. The depleting thread of fossil fuels, the significant increase in cost and the alarming environmental situation raises concerns. An Islanded DC microgrid, due to its novel characteristics of being able to withstand faulty conditions, has increased the reliability, accuracy, ease of integration, and efficiency of the power system. Renewable energy sources, characteristically DC, have wide usability in a distributive network and, accordingly, less circuitry and conversion stages are required, eliminating the need of reactive power compensation and frequency sync. Constant power loads (CPLs) are the reason for instability in the DC microgrid. Various centralized stability techniques have been proposed in the literature; however, the grid system collapses if there is a fault. To compensate, an efficient distributive control architecture, i.e., droop control method is proposed in this research. The significant advantage of using the droop control technique includes easy implementation, high reliability and flexibility, a reduced circulating current, a decentralized control with local measurements, the absence of a communication link and, thus, it is economic. Moreover, it offers local control for each individual power source in the microgrid. To investigate the stability of the islanded DC microgrid with constant power loads using the droop control technique, a small signal model of the islanded DC microgrid was developed in MATLAB/Simulink. Simulations were carried out to show the efficiency of the proposed controller and analyze the stability of the power system with constant power loads.

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Energy management and damping improvement of a DC microgrid with constant power load using interconnection and damping assignment-passivity based control

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331220960828 ◽

2020 ◽

pp. 014233122096082

Author(s):

Soumya Samanta ◽

Saumitra Barman ◽

Jyoti Prakash Mishra ◽

Prasanta Roy ◽

Binoy Krishna Roy

Keyword(s):

Energy Management ◽

Control Technique ◽

Effective Energy ◽

Constant Power ◽

Dc Microgrid ◽

Control Laws ◽

Control Approach ◽

Integral Action ◽

Passivity Based Control ◽

The Stability

This paper deals with (i) damping improvement and (ii) energy management of a DC microgrid for improvement of its stability. The direct current (DC) microgrid has a solar-photovoltaic system as a renewable source and fuel cell-battery combination as a backup system to supply power to constant power loads (CPLs). The presence of CPLs in a DC microgrid makes the stability problem more challenging since the negative impedance characteristics of CPLs bring instability into the system. A control approach using interconnection and damping assignment-passivity based control (IDA-PBC) is proposed in this paper to address both the objectives. The proposed control approach provides an efficient energy management, the required damping and also maintains the stability by making the system passive. The tuning parameters of the control laws are adapted incorporating the state of charge (SoC) for the effective energy management. In addition, an integral action is added with the proposed control laws to eliminate the steady-state error in the voltage level of the DC bus and load bus. The proposed IDA-PBC control along with an integral action is compared with four other control approaches, and reveals its better performances. The MATLAB/Simulink results show that the proposed control technique provides better responses in terms of providing damping and effective energy management.

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Stability Control for Electric Vehicles with Four In-Wheel-Motors Based on Sideslip Angle

World Electric Vehicle Journal ◽

10.3390/wevj12010042 ◽

2021 ◽

Vol 12 (1) ◽

pp. 42

Author(s):

Kun Yang ◽

Danxiu Dong ◽

Chao Ma ◽

Zhaoxian Tian ◽

Yile Chang ◽

...

Keyword(s):

Electric Vehicles ◽

Control Method ◽

Sliding Mode ◽

Stability Control ◽

Torque Control ◽

Wheel Load ◽

Sideslip Angle ◽

Distribution Method ◽

Load Rate ◽

The Stability

Tire longitudinal forces of electrics vehicle with four in-wheel-motors can be adjusted independently. This provides advantages for its stability control. In this paper, an electric vehicle with four in-wheel-motors is taken as the research object. Considering key factors such as vehicle velocity and road adhesion coefficient, the criterion of vehicle stability is studied, based on phase plane of sideslip angle and sideslip-angle rate. To solve the problem that the sideslip angle of vehicles is difficult to measure, an algorithm for estimating the sideslip angle based on extended Kalman filter is designed. The control method for vehicle yaw moment based on sliding-mode control and the distribution method for wheel driving/braking torque are proposed. The distribution method takes the minimum sum of the square for wheel load rate as the optimization objective. Based on Matlab/Simulink and Carsim, a cosimulation model for the stability control of electric vehicles with four in-wheel-motors is built. The accuracy of the proposed stability criterion, the algorithm for estimating the sideslip angle and the wheel torque control method are verified. The relevant research can provide some reference for the development of the stability control for electric vehicles with four in-wheel-motors.

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Analysis and Implementation of a Frequency Control DC–DC Converter for Light Electric Vehicle Applications

Electronics ◽

10.3390/electronics10141623 ◽

2021 ◽

Vol 10 (14) ◽

pp. 1623

Author(s):

Bor-Ren Lin

Keyword(s):

Electric Vehicles ◽

Output Voltage ◽

Frequency Control ◽

Input Voltage ◽

Pulse Frequency ◽

Switching Frequency ◽

Battery Charger ◽

Dc Microgrid ◽

Load Voltage ◽

Transportation Vehicle

In order to realize emission-free solutions and clean transportation alternatives, this paper presents a new DC converter with pulse frequency control for a battery charger in electric vehicles (EVs) or light electric vehicles (LEVs). The circuit configuration includes a resonant tank on the high-voltage side and two variable winding sets on the output side to achieve wide output voltage operation for a universal LEV battery charger. The input terminal of the presented converter is a from DC microgrid with voltage levels of 380, 760, or 1500 V for house, industry plant, or DC transportation vehicle demands, respectively. To reduce voltage stresses on active devices, a cascade circuit structure with less voltage rating on power semiconductors is used on the primary side. Two resonant capacitors were selected on the resonant tank, not only to achieve the two input voltage balance problem but also to realize the resonant operation to control load voltage. By using the variable switching frequency approach to regulate load voltage, active switches are turned on with soft switching operation to improve converter efficiency. In order to achieve wide output voltage capability for universal battery charger demands such as scooters, electric motorbikes, Li-ion e-trikes, golf carts, luxury golf cars, and quad applications, two variable winding sets were selected to have a wide voltage output (50~160 V). Finally, experiments with a 1 kW rated prototype were demonstrated to validate the performance and benefits of presented converter.

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Sliding Mode Control and Modified Generalized Projective Synchronization of a New Fractional-Order Chaotic System

Mathematical Problems in Engineering ◽

10.1155/2015/941654 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Junbiao Guan ◽

Kaihua Wang

Keyword(s):

Sliding Mode Control ◽

Fractional Order ◽

Chaotic System ◽

Secure Communication ◽

Sliding Mode ◽

Projective Synchronization ◽

Control Technique ◽

Order System ◽

Mode Control ◽

The Stability

A new fractional-order chaotic system is addressed in this paper. By applying the continuous frequency distribution theory, the indirect Lyapunov stability of this system is investigated based on sliding mode control technique. The adaptive laws are designed to guarantee the stability of the system with the uncertainty and external disturbance. Moreover, the modified generalized projection synchronization (MGPS) of the fractional-order chaotic systems is discussed based on the stability theory of fractional-order system, which may provide potential applications in secure communication. Finally, some numerical simulations are presented to show the effectiveness of the theoretical results.

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Evaluation of the system parameters degree of influence on the stability of a DC microgrid

2013 IEEE Grenoble Conference ◽

10.1109/ptc.2013.6652472 ◽

2013 ◽

Cited By ~ 1

Author(s):

Santiago Sanchez ◽

Marta Molinas

Keyword(s):

Dc Microgrid ◽

System Parameters ◽

The Stability

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Desain dan analisis pengaruh parameter PI dan variasi kecepatan pada respon sistem kontrol arah hadap prototype kendaraan listrik

Turbo Jurnal Program Studi Teknik Mesin ◽

10.24127/trb.v9i2.1246 ◽

2020 ◽

Vol 9 (2) ◽

Author(s):

Afif Caesar Distara ◽

Fatkhur Rohman

Keyword(s):

Control System ◽

Steady State ◽

Electric Vehicles ◽

Rise Time ◽

Small Error ◽

Settling Time ◽

System Stability ◽

Prototype System ◽

Stability Parameters ◽

The Stability

Electric vehicles are alternative vehicles that carry energy efficient. At this time the dominant vehicle uses ordinary wheels so that it will become an obstacle in the maneuver function that requires movement in various directions. With mechanum wheels the vehicle can move in various directions by adjusting the direction of rotation of each wheel. The problem is choosing the right control system for the control system needed by the vehicle. The purpose of this study is to determine and analyze the effect of variations in the value of PI (Proportional Integral) and speed of the vehicle to the stability response of the system to control the direction of prototype electric vehicles. This study method is an experiment that is by giving a treatment, then evaluating the effects caused by the research object. The results of this study can be concluded that the variation of PI constant values and speed variations have an effect on the stability parameters of the system, namely rise time, settling time, overshot, and steady state error. To get the best system stability response results can use the constant value PI Kp = 2; and Ki = 17; where the stability response of the system for direction control at each speed condition has a fairly good value with a fast rise time, fast settling time, small overshot and a small error steady state compared to other PI constant values in this study.Keywords: mechanum wheel, PI control, direction, prototype, system stability

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Bidirectional Power Flow Control in AC/DC Hybrid System under AC and DC Fault Conditions

JAREE (Journal on Advanced Research in Electrical Engineering) ◽

10.12962/j25796216.v3.i2.98 ◽

2019 ◽

Vol 3 (2) ◽

Author(s):

Wai Wai Hnin

Keyword(s):

Power Flow ◽

Storage System ◽

Control Technique ◽

Diesel Generator ◽

Dc Microgrid ◽

Photovoltaic Array ◽

Hybrid Microgrid ◽

Dc Bus ◽

Bidirectional Power Flow ◽

Ac Microgrid

This paper presents a hybrid AC-DC microgrid to reduce the process of multiple conversions in an individual AC microgrid or DC microgrid. The proposed hybrid microgrid compose of both AC microgrid and DC microgrid connected together by bidirectional interlink converter (BIC). Utility grid, 150kVA diesel generator (DG) and 100kW AC load are connected in AC microgrid. DC microgrid is composed of 100 kW photovoltaic array (PV), 20kW battery energy storage system (BESS) and 20kW DC load. The droop control technique is applied to control the system for power sharing within the sources in AC/DC hybrid microgrid in proportion to the power rating. When the faults occur at AC bus, protection signal applied to breaker for isolating the healthy and faults system. DC faults occur at DC bus, DC breaker isolate the AC and DC bus. The system performance for power flow sharing on hybrid AC-DC microgrid is demonstrated by using MATLAB/SIMULINK.

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