Control Strategy for Smooth Switching and Off-Grid Stable Operation of Multi-energy Complementary Microgrid

2021 ◽  
pp. 827-838
Author(s):  
Yinghua Lu ◽  
Xinran Li ◽  
Xiaolong Liu ◽  
Zhipu Liu ◽  
Zhen Luo
Keyword(s):  
Control Strategy ◽  
Stable Operation ◽  
Smooth Switching

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.

scholarly journals Novel Control Strategy for Enhancing Microgrid Operation Connected to Photovoltaic Generation and Energy Storage Systems

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1261
Author(s):  
Dina Emara ◽  
Mohamed Ezzat ◽  
Almoataz Y. Abdelaziz ◽  
Karar Mahmoud ◽  
Matti Lehtonen ◽  
...  
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Voltage Stability ◽  
Storage Systems ◽  
Voltage Source ◽  
Stable Operation ◽  
Energy Storage Systems ◽  
Dc Microgrid ◽  
Photovoltaic Generation ◽  
Dc Voltage

Recently, the penetration of energy storage systems and photovoltaics has been significantly expanded worldwide. In this regard, this paper presents the enhanced operation and control of DC microgrid systems, which are based on photovoltaic modules, battery storage systems, and DC load. DC–DC and DC–AC converters are coordinated and controlled to achieve DC voltage stability in the microgrid. To achieve such an ambitious target, the system is widely operated in two different modes: stand-alone and grid-connected modes. The novel control strategy enables maximum power generation from the photovoltaic system across different techniques for operating the microgrid. Six different cases are simulated and analyzed using the MATLAB/Simulink platform while varying irradiance levels and consequently varying photovoltaic generation. The proposed system achieves voltage and power stability at different load demands. It is illustrated that the grid-tied mode of operation regulated by voltage source converter control offers more stability than the islanded mode. In general, the proposed battery converter control introduces a stable operation and regulated DC voltage but with few voltage spikes. The merit of the integrated DC microgrid with batteries is to attain further flexibility and reliability through balancing power demand and generation. The simulation results also show the system can operate properly in normal or abnormal cases, thanks to the proposed control strategy, which can regulate the voltage stability of the DC bus in the microgrid with energy storage systems and photovoltaics.

Study on a global control strategy for rotation speed with different work states in variable-speed constant-frequency wind turbines

2011 ◽  
Vol 225 (7) ◽  
pp. 968-976 ◽  
Author(s):  
G Zheng ◽  
H Xu ◽  
X Wang ◽  
J Zou
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Control Strategy ◽  
Control Strategies ◽  
Stable Operation ◽  
Constant Frequency ◽  
Global Control ◽  
Control Rules ◽  
The Individual ◽  
And Control

This paper studies the operation of wind turbines in terms of three phases: start-up phase, power-generation phase, and shutdown phase. Relationships between the operational phase and control rules for the speed of rotation are derived for each of these phases. Taking into account the characteristics of the control strategies in the different operational phases, a global control strategy is designed to ensure the stable operation of the wind turbine in all phases. The results of simulations are presented that indicate that the proposed algorithm can control the individual phases when considered in isolation and also when they are considered in combination. Thus, a global control strategy for a wind turbine that is based on a single algorithm is presented which could have significant implications on the control and use of wind turbines.

Comparison of two control strategies for VSC-MTDC with wind farm

2021 ◽  
Vol 14 ◽  
Author(s):  
Congshan Li ◽  
Pu Zhong ◽  
Ping He ◽  
Yan Liu ◽  
Yan Fang ◽  
...  
Keyword(s):  
Power Control ◽  
Control Strategy ◽  
Voltage Stability ◽  
Wind Farm ◽  
Control Strategies ◽  
Wind Farms ◽  
Active Power ◽  
Stable Operation ◽  
Active Power Control ◽  
Dc Voltage

: Two VSC-MTDC control strategies with different combinations of controllers are proposed to eliminate transient fluctuations in the DC voltage stability, resulting from a power imbalance in a VSC-MTDC connected to wind farms. First, an analysis is performed of a topological model of a VSC converter station and a VSC-MTDC, as well as of a mathematical model of a wind turbine. Then, the principles and characteristics of DC voltage slope control, constant active power control, and inner loop current control used in the VSC-MTDC are introduced. Finally, the PSCAD/EMTDC platform is used to establish an electromagnetic transient model of a wind farm connected to a parallel three-terminal VSC-HVDC. An analysis is performed for three cases of single-phase grounding faults on the rectifier and inverter sides of a converter station and of the withdrawal of the converter station on the rectifier side. Next, the fault response characteristics of VSC-MTDC are compared and analyzed. The simulation results verify the effectiveness of the two control strategies, both of which enable the system to maintain DC voltage stability and active power balance in the event of a fault. Background: The use of a VSC-MTDC to connect wind power to the grid has attracted considerable attention in recent years. A suitable VSC-MTDC control method can enable the stable operation of a power grid. Objective: The study aims to eliminate transient fluctuations in the DC voltage stability resulting from a power imbalance in a VSC-MTDC connected to a wind farm. Method: First, the topological structure and a model of a three-terminal VSC-HVDC system connected to wind farms are studied. Second, an analysis is performed of the outer loop DC voltage slope control, constant active power control and inner loop current control of the converter station of a VSC-MTDC. Two different control strategies are proposed for the parallel three-terminal VSC-HVDC system: the first is DC voltage slope control for the rectifier station and constant active power control for the inverter station, and the second is DC voltage slope control for the inverter station and constant active power for the rectifier station. Finally, a parallel three-terminal VSC-HVDC model is built based on the PSCAD/EMTDC platform and used to verify the accuracy and effectiveness of the proposed control strategy. Results: The results of simulation analysis of the faults on the rectifier and inverter sides of the system show that both strategies can restore the system to the stable operation. The effectiveness of the proposed control strategy is thus verified. Conclusion: The control strategy proposed in this paper provides a technical reference for designing a VSC-MTDC system for wind farms.

Optimization of FengTai Power Plant 350MW Supercritical Unit Water Supply RB Control Strategy

2011 ◽  
Vol 130-134 ◽  
pp. 2527-2529
Author(s):  
Jin Tao Guo ◽  
Jiang Xin
Keyword(s):  
Power Plant ◽  
Water Supply ◽  
Control Strategy ◽  
Inner Mongolia ◽  
Power Grid ◽  
Supply System ◽  
Stable Operation ◽  
Pressure Curve ◽  
Sliding Pressure ◽  
Safety Range

The improvement of RB is significant for safety of both the power plant and power grid. This paper, took the 2 × 350MW unit of Inner Mongolia Huaneng Power Plant for instance, researched on three ways to improve water supply RB, like taking a proper sliding pressure curve, improving the water supply system and optimizing the boiler combustion. In the research, we succeeded to maintain main parameters of the unit within a safety range during RB operation, and avoided a unit trip accident causing by one single pump’s fault trip. Therefore, the research’s success settled a good base for the unit’s safe and stable operation.

scholarly journals Integrated control strategy for smooth switching of the PV and battery-storage micro-grid based on operation state tracking

2019 ◽  
Vol 2019 (16) ◽  
pp. 1062-1067
Author(s):  
Li Yang ◽  
Gao Song ◽  
Shi Wenhui ◽  
He Guoqing ◽  
Wang ZhengPing
Keyword(s):  
Control Strategy ◽  
Integrated Control ◽  
Battery Storage ◽  
State Tracking ◽  
Micro Grid ◽  
Smooth Switching ◽  
Grid Based

A control strategy for the stable operation of shunt active power filters in power grids

Energy ◽  
2016 ◽  
Vol 96 ◽  
pp. 325-334 ◽  
Author(s):  
Majid Mehrasa ◽  
Edris Pouresmaeil ◽  
Sasan Zabihi ◽  
Eduardo M.G. Rodrigues ◽  
João P.S. Catalão
Keyword(s):  
Control Strategy ◽  
Active Power ◽  
Power Grids ◽  
Stable Operation ◽  
Active Power Filters ◽  
Power Filters

Research on Modeling and Control Strategy of Parallel Hybrid Electric Back-Loading Compression Sanitation Vehicle

2013 ◽  
Vol 420 ◽  
pp. 355-362
Author(s):  
Rong Yang ◽  
Di Ming Lou ◽  
Pi Qiang Tan ◽  
Zhi Yuan Hu
Keyword(s):  
Fuel Consumption ◽  
Electric Vehicle ◽  
Control Strategy ◽  
Hybrid Electric Vehicle ◽  
Stable Operation ◽  
Parallel Hybrid Electric Vehicle ◽  
Fuel Consumption Reduction ◽  
Consumption Reduction ◽  
Parallel Hybrid ◽  
Hybrid Electric

Establish simulation models of the conventional and parallel hybrid electric back-loading compression sanitation vehicle by AVL CRUISE and MATLAB/Simulink software. Study on control strategy of parallel hybrid electric vehicle based on the work characteristics of back-loading compression sanitation. Results show that: about 24.5% fuel consumption reduction in hybrid modeling compared to the conventional sanitation vehicle under heavy commercial vehicle standard test cycle (C-WTVC, Adapted World Transient Vehicle Cycle), and battery SOC was little changed at 50%. About 32% fuel consumption reduction in hybrid compared to the conventional vehicle under the actual road testing spectrum, and SOC increased about 21.6% relative to the initial state. It controls the engine to work in more stable operation region and reduces engine idle time, but increases engine start-stop times. It also could provide some references for specific engine development of parallel hybrid electric vehicle

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