An Integral Droop for Transient Power Allocation and Output Impedance Shaping of Hybrid Energy Storage System in DC Microgrid
An Integral Droop for Transient Power Allocation and Output Impedance Shaping of Hybrid Energy Storage System in DC Microgrid
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DOI：
10.1109/tpel.2017.2741262
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发表时间：
2018-07
影响因子：
6.7
通讯作者：
Pengfeng Lin;Peng Wang;Jianfang Xiao;Junjun Wang;Chi Jin;Yi Tang
中科院分区：
文献类型：
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作者：
Pengfeng Lin;Peng Wang;Jianfang Xiao;Junjun Wang;Chi Jin;Yi Tang
混合储能系统(HESS)的功率分配是直流微电网的一个重要问题。受电容器充放电过程的电学特性启发，提出了一种积分下垂(ID)算法，并将其应用于高斜率储能集群(ES)。通过ID和常规V-P下垂的协调，可以本质上分散地实现HESS中的暂态功率分配。具有ID的ESS可以补偿电力需求的高频分量，而V-P下垂的ESS则响应负载功率的平稳变化。此外，ID系数可以根据慢响应ESS的额定斜坡率来设计，这有助于延长HESS的使用寿命。另一方面，为了便于评估恒功率负载供电系统的稳定性，提出了一种最小相对阻抗判据。基于MRIC的结果表明，所提出的ID可以整形HESS的输出阻抗，从而稳定整个系统。仿真和实验结果验证了该方法的可行性和有效性。
Power allocation in hybrid energy storage systems (HESSs) is an important issue for dc microgrids. In this paper, an integral droop (ID), inspired by the electrical characteristics of capacitor charging/discharging process, is proposed and applied to a cluster of energy storages (ESs) with high ramp rates. Through the coordination of the ID and conventional V-P droop, the transient power allocation in HESSs can be intrinsically realized in a decentralized manner. The high-frequency components of power demand can be compensated by the ESs with ID, whereas the ESs with V-P droop respond to the smooth change of load power. Additionally, the ID coefficient can be designed according to the nominal ramp rate of the ESs with slow response, which helps to extend the lifespan of the HESS. On the other hand, to easily assess the stability of the system feeding constant power loads, a minimum relative impedance criterion (MRIC) is developed. Based on MRIC, it is revealed that the proposed ID can shape the output impedance of the HESS and stabilize the entire system. The feasibility and effectiveness of ID are verified by both simulations and experimental results.