Abstract
With the rapid growth of distributed generation currently, DC microgrids energy system structure is being deployed in parallel with, or independently from, the main power grid network. The DC microgrids energy system structure is designed to provide an effective coordination with the aggregating distributed generators, energy storage, and connected loads. In this sense, the DC microgrids energy system structure can be connected to the grid network or can be off-grid network. In the mode of grid network connected, DC microgrids energy system structure is presented as a controllable entity. When it is necessary, DC microgrids energy system is connected in islanded mode to deliver reliable power to the grid network during the interrupted power supply from the grid network system. Having said that, the DC microgrids energy system structure is encompassed of renewable energy sources, energy storages and loads, and not excluding the grid network transmission. Hence, this chapter proposes to focus on designing and modelling a self-assistive controller using voltage droop method for DC distributed generators and storages which is a part of the DC microgrids energy system structure.
TopThis chapter proposes a complete design and model of a self-assistive controller which uses the voltage droop method to sense, measure, coordinate and control the connected DC distributed generators. The self-assistive controller sense and measure the output voltages from the DC distributed generators and effectively coordinate and control the power flow from the DC distributed generators to the connected loads. The self-assistive controller for DC distributed generators is divided into two (2) stages. In Stage I, the methodological design of the self-assistive controller using voltage droop method for DC Distributed Generators and Storages is presented and fundamental operation of the proposed controller is described. In the Stage II, SIMULINK – MATLAB software is used to model the self-assistive controller in terms of its electronic components is presented. During the modelling of each part in Stage II, each developed part is referred with the methodological design in Stage I. Completion of each part in Stage II is simulated and results obtained is recorded as preliminary finding which is used as reference results to model the next part in Stage II. The previously obtained results from previously modelled part is used to analyze the electronically developed circuit using the SIMULINK - MATLAB software. This modelling process is continued till the proposed self-assistive controller for DC distributed generators for the connected loads is modelled successfully. The difference in the obtained results in Stage II are studied and analyzed to make any necessary changes to the modelled system. After studying, analyzing and making necessary changes to the modelled system, final results are presented which demonstrate the sensing, measuring, coordination and control of proposed self-assistive controller for DC distributed generators using the voltage droop method. The obtained final results also demonstrated the effectiveness of energy management and optimize the available renewable energy resources as primary energy source for the connected loads.
Key Terms in this Chapter
Renewable Energy Sources: Renewable energy sources are known as solar, wind, biomass, tidal, and many more.
Off-Grid Network: A power system which is not connected to any kind of grid network.
DC Distributed Generators and Storages: DC distributed generators and storages are known as only to produce direct current (DC) source of supply.
Stand-Alone Hybrid Renewable Energy System: Stand-alone hybrid renewable energy system is referred to a power system which is not connected to any grid network.
Hybrid Microgrid System: Hybrid is known having two (2) or more resources connected to generate energy source supply. In this study, solar, wind, and battery as energy storage system is used. And microgrid system is referred to a small power system.
Modelling Hybrid Renewable Energy System: Modelling a hybrid renewable energy system is to model a solar, wind, and battery as energy storage system as a power system.
Assistive Controller Voltage Droop: The assistive controller is a controller assisted using some external characteristic such as voltages in this study. Hence, the voltage droop technique is used to assist the controller to make decisions.