scholarly journals Power Distribution Strategy of Microgrid Hybrid Energy Storage System Based on Improved Hierarchical Control

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3498 ◽  
Author(s):  
Tiezhou Wu ◽  
Wenshan Yu ◽  
Lujun Wang ◽  
Linxin Guo ◽  
Zhiquan Tang

Traditional hierarchical control of the microgrid does not consider the energy storage status of a distributed hybrid energy storage system. This leads to the inconsistency of the remaining capacity of the energy storage system in the process of system operation, which is not conducive to the safe and stable operation of the system. In this paper, an improved hierarchical control strategy is proposed: the first allocation layer completes the allocation between the distribution energy storage systems considering the state of hybrid energy storage systems, and the second allocation layer realizes the allocation within the hybrid energy storage systems based on variable time constant low-pass filtering. Considering the extreme conditions of energy storage systems, the transfer current is introduced in the second allocation process. The SOC (stage of charge) of the supercapacitor is between 40% and 60%, which ensures that the supercapacitor has enough margin to respond to the power demand. An example of a 300 MW photovoltaic microgrid system in a certain area is analyzed. Compared with the traditional hierarchical control, the proposed control strategy can reduce the SOC change of a hybrid energy storage system by 9% under the same conditions, and make the supercapacitor active after power stabilization, which is helpful to the stable operation of the microgrid.

2021 ◽  
Author(s):  
Gouri Rani Barai

Efficient supply of electric energy, maintaining power quality, and addressing intermittency of renewable energy and unpredictable demand fluctuations are challenges of a modern power grid. An individual energy storage technology seldom provides all the desired characteristics expected. A Hybrid Energy Storage System (HESS) including different types of energy storage systems can address these challenges. In this work a new formulation and algorithm was developed that optimally designs a grid-scale HESS for desired performances such as peak load shaving and power demand curve smoothening at the least capital cost. The proposed HESS comprised of a combination of Lithium Ion batteries, Flywheels, and Ultracapacitor based Energy Storage Systems. Real and synthetic power demand dataset representing different types of demand fluctuations were used in the analysis. The proposed formulation and algorithm was able to optimally size HESS such that it costs the least while performing in the desired manner.


2014 ◽  
Vol 1035 ◽  
pp. 23-26
Author(s):  
You Jie Ma ◽  
Hong Kun Lu ◽  
Xue Song Zhou

New energy generation parallel operation is an effective way for large-scale development and utilization of new energy generation. The instability of new energy, however, can bring a series of negative influence to stability of power grid. Adjusting the power fluctuations of new energy generation, achieving real-time output stable control, is one of the key technologies of stable operation. The hybrid energy storage system, including lithium ion battery and super capacitor, can reduce the fluctuation effectively. Then it can make new energy generation steady run. In addition, it can reduce the volume, weight and cost of the energy storage system compared with the single battery or super capacitor energy storage.


2021 ◽  
Author(s):  
Gouri Rani Barai

Efficient supply of electric energy, maintaining power quality, and addressing intermittency of renewable energy and unpredictable demand fluctuations are challenges of a modern power grid. An individual energy storage technology seldom provides all the desired characteristics expected. A Hybrid Energy Storage System (HESS) including different types of energy storage systems can address these challenges. In this work a new formulation and algorithm was developed that optimally designs a grid-scale HESS for desired performances such as peak load shaving and power demand curve smoothening at the least capital cost. The proposed HESS comprised of a combination of Lithium Ion batteries, Flywheels, and Ultracapacitor based Energy Storage Systems. Real and synthetic power demand dataset representing different types of demand fluctuations were used in the analysis. The proposed formulation and algorithm was able to optimally size HESS such that it costs the least while performing in the desired manner.


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