Unified Control for DC Microgrids

In the quest of more sustainable power supply, issues related to the operation and flexibility of distributed energy resources are becoming paramount. Microgrids (MGs) can contribute significantly to both problems and can play an important role in a new distributed conventional power system. Arising

Project Title

Unified Control for DC Microgrids

Project Area of Specialization

Internet of Things

Project Summary

In the quest of more sustainable power supply, issues related to the operation and flexibility of distributed energy resources are becoming paramount. Microgrids (MGs) can contribute significantly to both problems and can play an important role in a new distributed conventional power system. Arising challenges occurs in terms of energy management, reliability, system control, etc. The active sub-systems of the modern power grid have their promising potential responding to intermittent clean power generation and new energy storage. Partially brought by the electric vehicle battery. A lot of work has been done on AC microgrids in the past years also the idea of DC microgrid emerged soon after the concept of microgrid was proposed. Recent studies have shown that the DC microgrids are far more feasible than the AC counterparts. The comparison is done mainly in conversion efficiency, transmission efficiency, power supply reliability, controllability and protection. Stand-alone direct current (DC) micro grid belong to different owners and adopt different management and control strategies. This presents a major challenge to its optimal operation due to the difficulty of implementing a unified control. First, we formulate the optimal power flow problem of stand-alone dc microgrids. Then a dynamic solving algorithm is designed. It should be stressed that the algorithm can provide control commands for the three types of microgrids: 1) power control; 2) voltage control; and 3) droop control. This implies that you do not have to change control strategies of each single microgrid in a distributed system and the system is less influenced by the diversity of microgrids. Moreover, the control commands for power controlled and voltage controlled microgrids satisfy generation limits and voltage limits in both transient process and steady state. The focus is placed on the basic issues of control, operation, stability, and protection of DC microgrids.

Project Objectives

 Outcomes of the Project

• Minimization of voltage regulation
• To improve the power efficiency or The OPF model of stand-alone DC power system is formulated
• The proposed method does not change the original control strategy of each DG, which adapts to three most common control modes: power control, voltage control and droop control, breaking restriction of microgrid diversity.
• The control commands for power controlled and voltage controlled microgrids satisfy generation limits and voltage limits in both transient process and steady state.

Project Implementation Method

we solve this problem initially through mathematically modeling by making algorithms for different problem e.g voltage regulation, OPF (optimal power flow) and Droop Control.

we have to mak 3 models each one have it own task and then combine all of these three tasked machince in device so called as Unified Control for DC microgird.

Then we test all of these controls one by one as well as combine in simulation and checkout the results.

Benefits of the Project

Main Benifits

1. Energy Efficient 

2. Low cost control device

3. Max power Flow

4. Less voltage Regulation

5. Less current variation

6 Storage level 

7 Accomodate max number of microgrids 

Technical Details of Final Deliverable

In order to evaluate dc microgrid performance and design the basic control strategy, the performance assessment criteria are categorized into three groups according to their importance. They are: 1) Reliability criteria: referring to stable system operation and hardware safety. They ensure normal operation of the microgrid and system hardware, such as power-electronics devices, capacitors, transmission lines, generation units, and ESS, are not damaged. Reliability criteria are of the highest importance and must be met at any time. 2) Function criteria: such as renewable energy maximization and reliable power supply to loads. The basic objectives of a microgrid are to provide reliable power supply to local loads, extract renewable energy as much as possible (maximize power point tracking – MPPT), and maintain an optimal SOC for the ESS. These criteria should be met as long as the reliability criteria are ensured. 3) Optimization criteria: corresponding to those enhanced but not essential functions for system operation. Typical examples are smoothing exchange power and reactive (ac voltage) or active power support to the utility ac grid. Since the fluctuation of the exchange power via the G-VSC is not preferable for the utility grid, it may be desirable to smooth the power fluctuation before export (or import) to the utility grid. On some occasions, the G-VSC might be required to provide the ac grid with voltage or reactive power support. These functions are of benefit to a microgrid but are not essential for its operation.

Final Deliverable of the Project

HW/SW integrated system

Type of Industry

Energy

Technologies

Internet of Things (IoT)

Sustainable Development Goals

Affordable and Clean Energy

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com