A Dual Mode Control Strategy of SMES for Multifunctional Applications

2011 ◽  
Vol 225-226 ◽  
pp. 987-991 ◽  
Author(s):  
Wen Yong Guo ◽  
Li Ye Xiao ◽  
Shao Tao Dai

The superconducting magnetic energy storage system (SMES) has good characteristics such as high efficiency, quick response, no deteriorations, etc. However it is still far from wide application. The main obstacle is due to its high cost. One of the most effective ways to reduce the cost of SMES is to make it multifunctional. In this paper, a dual mode control strategy is proposed. With the proposed control strategy, The SMES can compensate voltage dip, current harmonics, reactive power, and active power fluctuation with a simple topology. The efficacy of the proposed control strategy is verified by simulation results.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.


2021 ◽  
Vol 69 (2) ◽  
pp. 5-12
Author(s):  
Zheng Li ◽  
Yan Qin ◽  
Xin Cao ◽  
Shaodong Hou ◽  
Hexu Sun

In order to meet the load demand of power system, BP based on genetic algorithm is applied to the typical daily load forecasting in summer. The demand change of summer load is analysed. Simulation results show the accuracy of the algorithm. In terms of power supply, the reserves of fossil energy are drying up. According to the prediction of authoritative organizations, the world's coal can be mined for 216 years. As a renewable energy, wind power has no carbon emissions compared with traditional fossil energy. At present, it is generally believed that wind energy and solar energy are green power in the full sense, and they are inexhaustible clean power. The model of wind power solar hydrogen hybrid energy system is established. The control strategy of battery power compensation for delayed power of hydrogen production is adopted, and different operation modes are divided. The simulation results show that the system considering the control strategy can well meet the load demand. Battery energy storage system is difficult to respond to short-term peak power fluctuations. Super capacitor is used to suppress it. This paper studies the battery supercapacitor complementary energy storage system and its control strategy. When the line impedance of each generation unit in power grid is not equal, its output reactive power will be affected by the line impedance and distributed unevenly. A droop coefficient selection method of reactive power sharing is proposed. Energy storage device is needed to balance power and maintain DC voltage stability in the DC side of microgrid. Therefore, a new droop control strategy is proposed. By detecting the DC voltage, dynamically translating the droop characteristic curve, adjusting the output power, maintaining the DC voltage in a reasonable range, reducing the capacity of the DC side energy storage device. Photovoltaic grid connected inverter chooses the new droop control strategy.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 642 ◽  
Author(s):  
Tiezhou Wu ◽  
Xiao Shi ◽  
Li Liao ◽  
Chuanjian Zhou ◽  
Hang Zhou ◽  
...  

In view of optimizing the configuration of each unit’s capacity for energy storage in the microgrid system, in order to ensure that the planned energy storage capacity can meet the reasonable operation of the microgrid’s control strategy, the power fluctuations during the grid-connected operation of the microgrid are considered in the planning and The economic benefit of hybrid energy storage is quantified. A multi-objective function aiming at minimizing the power fluctuation on the DC bus in the microgrid and optimizing the capacity ratio of each energy storage system in the hybrid energy storage system (HESS) is established. The improved particle swarm algorithm (PSO) is used to solve the objective function, and the solution is applied to the microgrid experimental platform. By comparing the power fluctuations of the battery and the supercapacitor in the HESS, the power distribution is directly reflected. Comparing with the traditional mixed energy storage control strategy, it shows that the optimized hybrid energy storage control strategy can save 4.3% of the cost compared with the traditional hybrid energy storage control strategy, and the performance of the power fluctuation of the renewable energy is also improved. It proves that the proposed capacity configuration of the HESS has certain theoretical significance and practical application value.


2012 ◽  
Vol 608-609 ◽  
pp. 487-493 ◽  
Author(s):  
Zuo Xia Xing ◽  
Guan Feng Zhang ◽  
Jin Song Liu ◽  
Xing Jia Yao

Since distributed power generation equipment such as wind power contain electric power fluctuation connected into the power grid, hybrid energy storage (HESS) equipment for power compensation is used to solve the problems of reliability and operation of the utility power grid. Constant power control and Fuzzy-Rules-based control of AC-DC and BESS is proposed for smoothing the random wind power fluctuations, considering the operating constraints of the HESS, such as state of charge (SOC) and wind power (Pout). The simulation is accomplished by using a 9MW wind farm and the HESS in Matlab, The results show that by the proposed control methods of the bi-directional DC-DC converter and the DC-AC converter, the energy storage system can smooth the wind power outputs and provide reactive power support to the grid.


Energy storage system plays a crucial role in providing stabilization and improving power quality in isolated microgrid, especially in renewable energy based microgrid systems. Among the renewable sources, Photovoltaic (PV) based power systems are famous and increasing day by day due to its merits and advantages. Three phase fault are common in microgrid and leads to unsteady condition in the PV output power. When there is a fault in solar PV system, the photovoltaic power output decreases and results in abnormal voltage drop in the system. Efficiency and reliability of PV system is also a major issue. To overcome the issues occur due to fault in isolated PV system, it is to have Fault Ride through (FRT) capabilities. When failure occurs in PV system, FRT capability allows the system to maintain stability. FRT also allows the PV system to survive the system during the condition of fault on the system. Moreover, energy storage systems plays major role in the PV based systems. A Super Conducting Magnetic Energy Storage system (SMES)is proposed in this paper which is for providing power stabilization in isolated microgrid under fault condition. SMES can provide the real and reactive power according to the requirements of PV based power system. The proposed SMES can be a good solution for minimizing the effect on the system due to fault condition in PV system. Using MATLAB/SIMULINK, isolated PV with SMES was simulated and analysed for its performance with and without fault condition. This proposed theory is proven by an extensive simulation results.


Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3060
Author(s):  
Yuyan Song ◽  
Yuhong Wang ◽  
Qi Zeng ◽  
Jianquan Liao ◽  
Zongsheng Zheng ◽  
...  

In a power system with wind farms, the point of common coupling (PCC) usually suffers from voltage instability under large wind speed variations and the load impact. Using the internal converter of a doubly fed induction generator (DFIG)-based wind turbine to provide voltage support auxiliary service is an effective scheme to suppress the voltage fluctuation at PCC. To satisfy the reactive power demand of the connected grid, an active voltage coordinate control strategy with the hybrid energy storage system of the wind farm is proposed. The dynamic reactive power balance model is established to show the interaction between the reactive power limitation of the wind farm and the reactive power compensation demand of the grid. This indicates the initial conditions of the active voltage coordinate control strategy. According to the critical operating point and the operation state of the DFIG, the active and reactive power coordinate control strategy composed of active ω-β coordinate control and active β control is proposed to enhance the reactive power support capability and stabilize the grid voltage. To compensate the active power shortage, an auxiliary control strategy based on the hybrid energy storage system is introduced. The simulation results show that the proposed strategy can suppress the voltage fluctuation effectively and make full use of primary energy.


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