Control Strategy of DC nanogrid Based on hierarchical bus voltage control and droop control

Author(s):  
Qunwei Xu ◽  
Zhiquan Ma ◽  
Pei Li ◽  
Hongyang Huang ◽  
Feng Chen ◽  
...  
2020 ◽  
Vol 185 ◽  
pp. 01064
Author(s):  
Yilonɡ Kanɡ ◽  
Ningkang Zheng ◽  
Xiangyang Yan ◽  
Huanruo Qi ◽  
Kai Li

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.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2418 ◽  
Author(s):  
Liancheng Xiu ◽  
Liansong Xiong ◽  
Ping Yang ◽  
Zhiliang Kang

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.


2018 ◽  
Vol 8 (10) ◽  
pp. 1966 ◽  
Author(s):  
Kaitlyn Bunker ◽  
Michael Cook ◽  
Wayne Weaver ◽  
Gordon Parker

Reliability is a key consideration when microgrid technology is implemented in military applications. Droop control provides a simple option without requiring communication between microgrid components, increasing the control system reliability. However, traditional droop control does not allow the microgrid to utilize much of the power available from a solar resource. This paper applies an optimal multidimensional droop control strategy for a solar resource connected in a microgrid at a military patrol base. Simulation and hardware-in-the-loop experiments of a sample microgrid show that much more power from the solar resource can be utilized, while maintaining the system’s bus voltage around a nominal value, and still avoiding the need for communication between the various components.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mingche Li ◽  
Jiangwei Fan ◽  
Lihui Qiao

The main control objective of a DC microgrid with a multibus structure is to stabilize the bus voltage and maintain the power balance of the whole system. An adaptive droop control strategy for multibus DC microgrid based on consensus algorithm is proposed. It is based on platform multiagent system, which is realized by network protocol. Under the condition of a weak communication network, the bus at all levels can realize regional power autonomy through packet consensus protocol. A hybrid simulation platform composed of Jade, MacSimJX, and Simulink is built to verify the effectiveness of the control strategy.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1842 ◽  
Author(s):  
Fuyin Ni ◽  
Zhengming Li ◽  
Qi Wang

In order to improve the functionality and efficiency of a unified power quality conditioner (UPQC), a DC-link bus integrated photovoltaic charging module is proposed in a UPQC. It can generate power for essential loads apart from providing energy to a DC-link bus. A conventional proportional integral (PI) controller fails to run smoothly in dynamic conditions of the micro-grid, since it has poor capabilities in determining suitable values of proportional gain and integral gain. So, the optimization algorithm for a PI controller based on chaos particle swarm optimization based on a multi-agent system (CPSO-MAS) algorithm was developed in this paper to overcome properties such as intermittent instability in the micro-grid. Through verification by simulation and experiment of UPQC harmonic compensation, it showed that the proposed DC link bus voltage control strategy can be effectively applied to UPQC towards various conditions related to voltage and current distortion. In addition, it proved that the proposed strategy has faster convergence than other algorithms, which enhances the stability of DC-link bus voltage. Hence, the contribution presented in this paper is to provide a novel approach for the power quality improvement of UPQC.


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