DC MICROGRID CONTROL AND PROTECTION

Abstract

The thesis investigates the control and protection of ac dc micro grid. The thesis focuses on local control schemes for different converters in the dc micro grid in presence of two PV generators, and a Battery connected on the dc side. Distributed power supplies and power storage units are compatible with DC converters micro grid bus. basic requirement of micro grid is current sharing and there are many ways of current sharing. In many types of current sharing methods there are interconnections between the grid and the network, so it is overly complex to design this. So, we use search type of method in which there is no interconnection between them, and they can implement easily and the simplest one is droop control. [1] In the droop control, they are not interconnected. But there are some drawbacks. When we connect to one or more services and parallel and applied to control in this due to the current selling when the current increases the voltage decreases due to this group occurs in the system It differs from those methods such as the average current method, the master-slave method, traditional droop control method. droop control method does not require communication between converters and is widely modified. However, in standard drop control, the system deals with tradeoff between power control and current sharing and causes a decrease in power in the event of a positive current sharing. Droop control, a DC micro grid control system, does not require a connection link. However, droop control has some drawbacks, such as a misalignment of the load between the corresponding converters and the deterioration of the power supply control. This paper is proposed flexible drop controller to minimize common control problems. Droop parameters are tested online and are exchanged using current sharing barriers to reduce deviations fromcurrent load sharing. [2] In addition, the droop lines are replaced by a second loop to eliminate the DCMG bus power deviation. Proposed the algorithm is implemented under input (pv and battery) and load resistance voltages. Simulations and test results show the efficiency of the method presented compared to the old controls. In this paper, to improve system performance, we suggest a novel way to control the voltage drop, such as systematically updating each set voltage setting of converts. As shown in the simulation, the proposed method improves electrical power control without significant disruption to the current sharing function. In adaptive Droop control method, we control the system online. In this paper we implement this model in MATLAB/Simulink. This project uses a shunt controller to implement DC micro grid protection. Primary sources such as the sun, wind, etc. are primarily used to power AC loads. Therefore, DC power is supplied to the AC load through an intermediate circuit, but the AC load requires an AC power supply. To supply AC power, an inverter is used to convert the combined DC power to AC power. A battery with a BDC converter is used for buffering. In the event of an error such as a ground fault on the load side, the fact device implements a PI controller like a shunt controller to mitigate the received error and deliver high power quality to the load. Two main cases are conceivable with compensator and with compensator. Results related to this proposed work can be evaluated using Matlab/Simulink software.