Study of Supercapacitor Energy Storage Converter with Unbalanced and Nonlinear Loads

2014 ◽  
Vol 494-495 ◽  
pp. 1561-1568
Author(s):  
Ning Ning Li ◽  
Xi Sheng Tang ◽  
Guo Wei Zhang
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Output Voltage ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Voltage Fluctuation ◽  
Nonlinear Loads ◽  
Influence Mechanism ◽  
Zero Sequence ◽  
Supercapacitor Energy Storage

A novel topology structure of supercapacitor energy storage converter (ESC) is presented with two cascaded bidirectional DC/DC converters connected to a bidirectional DC/AC converter. It can promote the energy utilization rate of supercapacitor and improve the ability of powering unbalanced and nonlinear loads. The effect of the midpoint voltage fluctuation of the cascaded connected DC bus capacitors on output voltage is analyzed, followed by the influence mechanism unbalanced and nonlinear loads. The control strategy to restrain the unbalance and zero sequence harmonic is proposed. The theoretical analysis and the proposed method are verified through simulations and experiments on a 100kVA supercapacitor ESC prototype.

scholarly journals Output Voltage Control of MMC-Based Microgrid Based on Voltage Fluctuation Compensation Sliding Mode Control

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Sheng Xue ◽  
Xinggui Wang ◽  
Xiaoying Li
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Output Voltage ◽  
Sliding Mode ◽  
Sliding Mode Controller ◽  
Voltage Fluctuation ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
System Output ◽  
Dc Component

As a novel topology of microgrid, the output voltage control of MMC half bridge series microgrid (MMC-MG) is rarely studied. In this paper, on the basis of fully analyzing the mechanism of output voltage fluctuation of MMC-MG under the condition of islanded mode, a control strategy of a hybrid energy storage system is proposed to reduce the generating module (GM) DC-link voltage fluctuation caused by the randomness of renewable energy microsource output power. Moreover, in order to further improve the stabilization of the MMC-MG output voltage and meet the requirements of fast voltage recovery and antijamming, a sliding mode controller is designed. Then, a voltage fluctuation compensation controller is designed to suppress the DC component and fundamental frequency deviation of system output voltage caused by GM DC-link voltage fluctuation. The proposed control approach is validated against simulations using MMC-MG models with 4-GM per arm. The results show that the proposed hybrid energy storage control strategy can suppress the GM DC-link voltage fluctuation, the sliding mode controller can stabilize the system output voltage when the load drastic changes, and the fluctuation compensation strategy can suppress the DC component and the fundamental frequency deviation of system output voltage.

scholarly journals Power Limit Control Strategy for Household Photovoltaic and Energy Storage Inverter

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1704
Author(s):  
Zhongyan Xu ◽  
Shengyu Tao ◽  
Hongtao Fan ◽  
Jie Sun ◽  
Yaojie Sun
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Power Grid ◽  
Experimental Studies ◽  
Active Power ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Frequency Regulation ◽  
Upper Limit ◽  
Power Limit

The increased installation capacity of grid-connected household photovoltaic (PV) systems has been witnessed worldwide, and the power grid is facing the challenges of overvoltage during peak power generation and limited frequency regulation performance. With the dual purpose of enhancing the power grid safety and improving the PV utilization rate, the maximum feed-in active power can be regulated by modifying the maximum power point tracking (MPPT) algorithm and battery energy storage (BES) accessibility as control instructions. However, the existing methods not only waste installed PV capacity, but it becomes no longer accessible when the state of charge (SOC) of the BES approaches its upper limit. In response to the above problem, this paper proposes a power limit control strategy to coordinate the MPPT algorithm and the BES accessibility. The proposed strategy directly controls the inverter output current according to the power limit instructions from the electric operation control centers, leading to a bus voltage difference. The difference serves as a control signal for BES and PV. Under a power-limiting scenario, priority is given to power regulation through energy storage to absorb the limited active power. When the SOC of the BES reaches the upper limit of charging, modification of the PV MPPT algorithm facilitates the inverter output power to meet the power limit requirements. To further verify the effectiveness of the proposed power limit control strategy, both simulation and experimental studies are conducted, which consistently indicated a synchronized inverter current with grid voltage and a rapid power response of the power-limiting instruction within 0.2 s. The power limit control strategy not only improves the PV energy utilization but also supports the safe and reliable operation of the power gird in the context of soaring renewable energy penetration.

A New Power Allocation Strategy of Supercapacitor/Battery Hybrid Energy Storage System for Electric Vehicles

2013 ◽  
Vol 724-725 ◽  
pp. 1389-1392
Author(s):  
Yu Fan ◽  
Li Zhang ◽  
Kai Wang
Keyword(s):  
Energy Storage ◽  
Power Allocation ◽  
Electric Vehicles ◽  
Storage System ◽  
Energy Storage System ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Hybrid Energy Storage System

This paper presents a new power allocation method in the electrical hybrid energy storage system composed by batteries and supercapacitors (SCs) for electric vehicles (EVs). Based on the speed of EVs, the new power sharing strategy, adapted to different kinds of load profiles, regulates the SC state of charge (SOC). By comparison, the new strategy showed the shortest accelerating time and least power losses, which can efficiently improve dynamic performance and energy utilization rate.

scholarly journals Power Distribution Strategy for an Electric Bus with a Hybrid Energy Storage System

2021 ◽  
Vol 12 (3) ◽  
pp. 154
Author(s):  
Yu Zhang ◽  
Kai Li ◽  
Shumei Cui ◽  
Yutian Sun
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Power Distribution ◽  
Storage System ◽  
Energy Storage System ◽  
Utilization Rate ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Power Battery ◽  
Electric Bus

To address the power distribution problem that occurs in hybrid energy storage systems (HESSs) in electric vehicles, a fuzzy control distribution method is proposed in this paper, taking the vehicle demand power; supercapacitor power, PSC;; and lithium battery power, Pbat, as the inputs and the power distribution factor of the supercapacitor as the output to control the power distribution of the composite energy storage system, in addition to dividing the whole working condition into three time scales, namely, long, medium and short. In this study, we conducted a comprehensive analysis and comparison with typical control methods regarding the energy storage element output power, battery state of charge (SOC) change, energy flow diagram and power frequency. The simulation experiment results show that the proposed strategy is more effective in reducing the peak output power of the power battery, improving the effective power utilization rate of HESS and the effective energy utilization rate. In order to further verify the effectiveness of the control strategy, a pure electric bus power system test bench was built based on similar principles, and a representative time period under the driving conditions of the China city bus (CHTC-B) was selected, involving an acceleration process from 30 to 48 s (process 1), a uniform speed process from 636 to 671 s (process 2) and a regenerative braking process from 1290 to 1304 s (process 3), further verifying the effectiveness and feasibility of the proposed control strategy.

The Control Strategy Study on Combined Mechanical and Electrical Braking of 8 x 8 Vehicles Driven by Wheel Hub Motor

2014 ◽  
Vol 898 ◽  
pp. 578-581
Author(s):  
Yu Lin Yan ◽  
Jia Qi Li ◽  
Zi Li Liao ◽  
Chun Guang Liu
Keyword(s):  
Fuzzy Control ◽  
Electric Vehicles ◽  
Electric Drive ◽  
Control Strategy ◽  
Control Method ◽  
Energy Utilization ◽  
Brake System ◽  
Utilization Rate ◽  
Strategy Study

In order to recycle part of the brake energy in the driving hub motor of the 8X8 electric vehicles. And the energy utilization rate of electric drive vehicles should be increased, the wear of mechanical brake system should be reduced. A fuzzy control method is established for mechanical and electrical joint brake. It can be used to establish a principle of the distribution of brake. Through the simulation on MATLAB platform, it shows that this control method is efficient in improvement of brake ability, distribution of brake distribution, and the energy recycling.

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