An Analysis on the Stability of the Electric Vehicles Connected Power System According to Charging Cost with Price Elasticity

2016 ◽  
Vol 65 (9) ◽  
pp. 1577-1582
Author(s):  
Junhyeok Kim ◽  
Joorak Kim ◽  
Chulhwan Kim
Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2288
Author(s):  
Zhenghao Wang ◽  
Yonghui Liu ◽  
Zihao Yang ◽  
Wanhao Yang

In recent years, wind power systems have been used extensively, which not only improve the efficiency of current conventional power generation systems, but also can save traditional fossil fuel resources. However, considering the instability of wind power, after being grid connected, it can easily cause an impact on the stability of the grid operation. Considering the above problems, this paper considers to make full use of the energy storage part of electric vehicles (EVs) to increase the stability of grid operation. Based on the mathematical model, this paper studies the load frequency control (LFC) problem of a multi-region interconnected power system with wind power and EVs. First, since the system states are difficult to be monitored, a state observer is designed to estimate the state. Based on this, the integral sliding mode controller (SMC) is designed to realize the LFC of the interconnected power system. Meanwhile, to obtain better control performance, this paper further analyzes and optimizes the controller parameters based on Lyapunov stability theory. At last, simulations are carried out for the power systems with two regions in Simulink. The results show that the designed controllers are effective to compensate the load demand disturbances. In addition, it is demonstrated that the battery storage of EVs can play the role of peak-shaving and valley-filling in LFC.


2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Kun Yang ◽  
Danxiu Dong ◽  
Chao Ma ◽  
Zhaoxian Tian ◽  
Yile Chang ◽  
...  

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.


2011 ◽  
Vol 383-390 ◽  
pp. 4151-4157
Author(s):  
Wen Qi Tian ◽  
Jing Han He ◽  
Jiu Chun Jiang ◽  
Cheng Gang Du

With the increase of new energy power generation, the requirement of smart grid and the popularity of electric vehicles, the research focus on V2G. With Electric vehicles being distributed energy storage or distributed generation, peak regulation in power system is involved in important functions of V2G. In order to achieve peak regulation function, the paper has analyzed the control relationship between the electric vehicles, V2G station and electric vehicle charge\ discharge control center, presented charge and discharge control strategy based on the two levels of electric vehicle charge\discharging control center and V2G station control layer and introduced algorithms and examples to achieve these strategies.


Author(s):  
Yu Cai ◽  
Wei Li ◽  
Bao Zhang ◽  
Wenjian Wu ◽  
Deren Sheng ◽  
...  

Fast valving of ultra-supercritical unit has great effects on over-speed prevention, load-shedding control, transient stability analysis of electrical system and other security problems. The purpose of fast valving is to maintain the stability of power system once fault or load shedding of unit occurs in the electric power system. Therefore, it is of great significance to study the reliability of fast valving for ultra-supercritical unit. In this paper, the KU ( short shedding) logic condition of SIEMENS T3000 system is analyzed as the research object of fast valving. The unit can be avoided over speed by monitoring the unit load and fast valving under faulty grid conditions based on the KU control. A series of measures will be taken after KU is triggered, for instance the governing valving will be closed quickly and the DEH (digital electro-hydraulic) control of the steam turbine will be switched to speeding control mode. On the other hand, the unit will return to normal operation if the transient fault of power grid disappears. The key contributions of this thesis include three parts: Firstly, based on the analysis of control characteristics of ultra-supercritical unit and protective logic and triggered conditions of KU function, a novel dynamic model by coupling the fast valving of steam turbine and the transient stability of generator is established by applying the PSCAD software. Then, the dynamic response process of ultra-supercritical unit is simulated and calculated by adopting the coupling dynamic model when KU function is triggered. Also the influence factors and reliability of fast valving are analyzed under transient fault conditions. Finally, two optimized measures by increasing the time delay and the speed of quantitative judgment are put forward to reduce risks and avoid the misoperation of signal distortion which may be caused by the power transmitter under transient fault conditions. The results of this study can not only help to evaluate the reliability of fast valving function scientifically in power grid transient fault, but also guide the technicians to analyze the stability of the power grid.


Author(s):  
Swathi Kommamuri ◽  
P. Sureshbabu

Power system stability improvement by a coordinate Design ofThyristor Controlled Series Compensator (TCSC) controller is addressed in this paper.Particle Swarm Optimization (PSO) technique is employed for optimization of the parameterconstrained nonlinear optimization problem implemented in a simulation environment. The proposed controllers are tested on a weakly connected power system. The non-linear simulation results are presented. The eigenvalue analysis and simulation results show the effectiveness and robustness of proposed controllers to improve the stability performance of power system by efficient damping of low frequency oscillations under various disturbances.


2015 ◽  
Vol 35 (1Sup) ◽  
pp. 42-49 ◽  
Author(s):  
Luis Fernando Rodríguez-García ◽  
Sandra Milena Pérez-Londoño ◽  
Juan José Mora-Flórez

<span>Current electric power systems have an increasing penetration of electric vehicles, and its effect has to be considered in different <span>studies, such as optimal dispatch or voltage stability, among others. Additionally, considering that power system analysis becomes <span>complex when the number of buses increase, this paper presents a methodology for aggregation of load areas that use a measurement-based load modeling approach based on an evolutionary computational technique and a classical reduction method. This aggregate <span>load area model is proposed to reduce areas that consider electric vehicle (EV) load models. The proposed method provides a static <span>equivalent load model and an equivalent network that can be used to reduce the computational effort required by power system<br /><span>studies. In order to validate the application of the proposed methodology, a 30-bus power system considering several disturbances <span>and levels of penetration of the electric vehicles was used. The results show that the equivalent network model allows the reproduction <span>of different events with an acceptable accuracy when it is compared to the original system behavior.</span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span>


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