Research Of Related Control Strategies For Low-voltage DC Micro-grid

AbstractIn recent years, with the continuous depletion of resources and environmental pollution are increasingly showing the seriousness of the development of the rational development of new resources and smart distribution grid is imminent. Based on the above background, DC micro-grid with a new grid structure model gradually been developed, there’s this new model grid structure with our current power development coincides with the necessary human,gradually gained widespread attention.Compared with the traditional exchange of micro network structure, the current progress for DC micro-grid is still relatively slow, and its energy management strategy, systems Control Strategy is not very comprehensive. Between this, the paper low voltage DC micro-grid in a study related to the control strategy to further promote the development of DC micro-grid to make a contribution.Firstly, the paper studies the structure of the required two DC micro-grid networks, and each individual unit to build the component parts of this DC micro-grid structure built to expand the basic principle component analysis and models. Discusses the operation of photovoltaic micro-source ideas(works) in MATLAB simulation software for photovoltaic micro sources were built mathematical models and simulation, simple exposition of its output characteristics, and using the disturbance observer method, completed its MPPT output;battery, operating characteristics of the fuel cell, the basic operating principles and characteristics of the composition of output DC micro-grid is analyzed and judgment; the operating principle of DC micro-grid system within the composition of the relevant converter(DC / DC, AC / DC) and dynamic characteristics are described.Then, the introduction of a DC micro-grid system DC bus voltage control strategy. Man DC micro-grid structure model to droop control method based on the method of setting the threshold voltage, the DC bus system to set a different voltage level, and then on the basis of the operating characteristics of DC micro-grid in a different system characteristics under different operating modes, according to the system DC bus voltage change, the respective components of the system elements are designed within its corresponding control strategy, so that the photovoltaic cell can operate in constant voltage operation mode with MPPT output;the battery on the basis of the corresponding control strategy under realize the system bus voltage changes with its own charge and discharge characteristics of coordination; when the system is overloaded running, this time by cutting load control strategies to achieve stability control DC micro-grid system DC bus voltage, prompting system DC bus voltage is restored to an acceptable range. Simulation results show that: the system is running and net balance system power balance can be achieved by two-way AC / DC converter to achieve, prompting bus voltage is maintained within a certain range; the system is in island operation mode, the simulation analysis results droop The system can control the DC bus voltage is maintainedwithin a certain range, but the DC bus voltage to the system brought a certain influence,namely the introduction of bias voltage.Finally, based on the introduction of multi-Agent(Agent) control technology DC micro grid energy management strategies. This paper uses a DC micro-grid model, set the Multi-Agent contains a micro-source operating mechanism and micro network proxy agent.Define the operational responsibilities of each agency within the system, namely micro-grid control agent coordination and management of the micro-source agent, micro main source agent to achieve its own working state management and control. The simulation results, based on Multi-Agent Control DC micro-grid energy management strategies that can achieve a good micro-grid energy management and control systems.