scholarly journals Research on power control strategy of household-level electric power router based on hybrid energy storage droop control

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kun Huang ◽  
Yanman Li ◽  
Xiaoyan Zhang ◽  
Lei Liu ◽  
Yanbin Zhu ◽  
...  
Keyword(s):  
Power Control ◽  
Control Strategy ◽  
Control Unit ◽  
Stable Operation ◽  
Droop Control ◽  
Hybrid Energy ◽  
Household Level ◽  
Dc Bus ◽  
Bus Voltage ◽  
The Stability

AbstractIn the light of user-side energy power control requirements, a power control strategy for a household-level EPR based on HES droop control is proposed, focusing on the on-grid, off-grid and seamless switching process. The system operating states are divided based on the DC bus voltage information with one converter used as a slack terminal to stabilize the DC bus voltage and the other converters as power terminals. In the on-grid mode, the GCC and the HES are used as the main control unit to achieve on-grid stable operation, whereas in the off-grid mode, the PV, HES and LC are used as the main control unit at different voltages to achieve stable operation of the island network. Finally, a DC MG system based on a household-level EPR is developed using the PSCAD / EMTDC simulation platform and the results show that the control strategy can effectively adjust the output of each subunit and maintain the stability of the DC bus voltage.

scholarly journals Research on Bus Voltage Control Strategy of Off-grid DC Microgrid

2020 ◽  
Vol 185 ◽  
pp. 01064
Author(s):  
Yilonɡ Kanɡ ◽  
Ningkang Zheng ◽  
Xiangyang Yan ◽  
Huanruo Qi ◽  
Kai Li
Keyword(s):  
Control Strategy ◽  
High Reliability ◽  
Voltage Control ◽  
Droop Control ◽  
Voltage Control Strategy ◽  
Dc Microgrid ◽  
Voltage Quality ◽  
Dc Bus ◽  
Bus Voltage

It is important to achieve stability of bus voltage in control of DC microgrids. In the DC microgrid, the traditional droop control method is usually adopted to stabilize the bus voltage for its high reliability and cost-effectiveness. However, line resistance will reduce the voltage quality of the DC bus in actual situations. In order to improve the voltage quality of the DC bus, a novel bus voltage control strategy based on modified droop characteristic is proposed. Finally, the simulation model of the off-grid DC microgrid with improved droop control strategy is built on PSCAD/EMTDC platform, and the results verify the effectiveness and feasibility of the proposed control strategy.

scholarly journals Hierarchical and Droop Method for DC Micro-grid Bus Voltage under Isolated operation

2020 ◽  
Vol 185 ◽  
pp. 01062
Author(s):  
Xiangyang Yan ◽  
Ningkang Zheng ◽  
Yilong Kang ◽  
Huanruo Qi ◽  
Kai Li ◽  
...  
Keyword(s):  
Control Strategy ◽  
Power Supply ◽  
System Level ◽  
Level Control ◽  
New Energy ◽  
Operation Control ◽  
Micro Grid ◽  
Dc Bus ◽  
Bus Voltage ◽  
The Stability

Nowadays, distributed generation technology is of great help to the efficient utilization of new energy. If the distributed power supply is connected to the DC micro-grid, it will be more secure and reliable. Therefore, it is necessary to control the voltage stability of the DC bus and ensure the balance of the source charge power of system to ensure the power supply quality and safety of the DC micro-grid. There are two operation modes of DC micro-grid: connected operation and isolated operation, and isolated operation control is the foundation and key of system-level control of DC micro-grid. To solve the problem of bus voltage fluctuation in isolated dc micro-grid, this study proposes a voltage hierarchical-droop control strategy for DC micro-grid, which can effectively improve the stability of the DC bus voltage. Last, this study builds the simulation model of DC micro-grid in the MATLAB/Simulink platform to verify the validity and feasibility of the proposed control strategy.

scholarly journals Inertial and Damping Characteristics of DC Distributed Power Systems Based on Frequency Droop Control

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2418 ◽  
Author(s):  
Liancheng Xiu ◽  
Liansong Xiong ◽  
Ping Yang ◽  
Zhiliang Kang
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Strategy ◽  
Power Grid ◽  
Voltage Control ◽  
Droop Control ◽  
Damping Effect ◽  
Distributed Power Systems ◽  
Dc Bus ◽  
Bus Voltage

With high penetration of renewable energy, DC distributed power systems (DDPSs) need to improve the inertia response and damping capacity of the power grid. The effects of main circuit parameters and control factors on the inertia, damping and synchronization of the DDPS were studied in this paper. Firstly, the dynamic model of DDPSs based on frequency droop control is established in the DC voltage control (DVC) timescale. Then, a static synchronous generator (SSG) model is used to analyze the parameters that affect the inertial level, damping effect and synchronization capability of the DDPS. The analysis results show that an optimal design of the frequency droop coefficient and proportional integral (PI) parameters of the DC bus voltage control loop can equivalently change the characteristics of inertia and damping when the frequency droop control strategy is applied to the DC/DC converter and the DC bus voltage control strategy is used in the grid-tied inverter. Simulation results verify the correctness of the conclusions. This paper helps to design an effective control strategy for DDPSs to enhance the inertial level and damping effect of the power grid and to improve the stable operation capability of renewable energy systems.

scholarly journals A control strategy for battery/supercapacitor hybrid energy storage system

2021 ◽  
Vol 2108 (1) ◽  
pp. 012091
Author(s):  
Congzhen Xie ◽  
Jigang Wang ◽  
Bing Luo ◽  
Xiaolin Li ◽  
Lei Ja
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Storage System ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Hybrid Energy Storage System ◽  
Dc Bus ◽  
Bus Voltage

Abstract In DC microgrid (MG), the hybrid energy storage system (HESS) of battery and supercapacitor (SC) has the important function of buffering power impact, which comes from renewable energy sources (RES) and loads. This paper proposes a HESS control strategy with DC bus voltage self-recovery function. High and low frequency power decomposition based on virtual droop control, and DC bus drop voltage is compensated by added proportional integral regulation. The relationship between DC bus voltage recovery and super-capacitor (SC) state of charge (SoC) recovery is analyzed. The system can realize stable energy storage, supply under frequent load power impact. The effectiveness of the proposed control strategy is verified by simulation in MATLAB/Simulink.

scholarly journals Research on Zero-Voltage Ride Through Control Strategy of Doubly Fed Wind Turbine

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2287
Author(s):  
Kaina Qin ◽  
Shanshan Wang ◽  
Zhongjian Kang
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Control Strategy ◽  
Large Scale ◽  
Sliding Mode ◽  
Stable Operation ◽  
Wide Range ◽  
Dc Bus ◽  
Doubly Fed ◽  
Zero Voltage

With the rapid increase in the proportion of the installed wind power capacity in the total grid capacity, the state has put forward higher and higher requirements for wind power integration into the grid, among which the most difficult requirement is the zero-voltage ride through (ZVRT) capability of the wind turbine. When the voltage drops deeply, a series of transient processes, such as serious overvoltage, overcurrent, or speed rise, will occur in the motor, which will seriously endanger the safe operation of the wind turbine itself and its control system, and cause large-scale off-grid accident of wind generator. Therefore, it is of great significance to improve the uninterrupted operation ability of the wind turbine. Doubly fed induction generator (DFIG) can achieve the best wind energy tracking control in a wide range of wind speed and has the advantage of flexible power regulation. It is widely used at present, but it is sensitive to the grid voltage. In the current study, the DFIG is taken as the research object. The transient process of the DFIG during a fault is analyzed in detail. The mechanism of the rotor overcurrent and DC bus overvoltage of the DFIG during fault is studied. Additionally, the simulation model is built in DIgSILENT. The active crowbar hardware protection circuit is put into the rotor side of the wind turbine, and the extended state observer and terminal sliding mode control are added to the grid side converter control. Through the cooperative control technology, the rotor overcurrent and DC bus overvoltage can be suppressed to realize the zero-voltage ride-through of the doubly fed wind turbine, and ensure the safe and stable operation of the wind farm. Finally, the simulation results are presented to verify the theoretical analysis and the proposed control strategy.

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