Abstract:
As the population of the world is increasing, simultaneously the demand for energy is also on the increase. The world super power’s monopoly on fossil fuel and its reservoir depletion takes the world towards renewable energy resources such as Wind, Solar etc. As more power electronic interfaced distributed generation (DG) is connected to the conventional power system, so, construction of the power system would be changed. Renewable energy resource, DG, is connected with the system through Voltage Source Inverter (VSI). The DGs based on power electronic Interface effects the power quality and safe operation of power system So the concept of Micro grid is developed to overcome power quality and operation issues which occurs due to PE based DG’s. Micro grid is an active distribution network having loads and distributed generations, which can be operated autonomously, with grid and have effective control. Micro grid has two modes of operation. In grid-connected, MG is connected with utility grid and work as autonomously in Islanded mode. (An effective control is required for optimal and stable operation of MG) For optimal performance, So, the control layers of MG are divided into Primary and Secondary controls. In grid-connected case, the primary controller regulates the output active and reactive power of DG and direct PQ control strategy is used as a secondary controller. In islanded it is used for voltage and frequency control of every DG. The secondary controller provides power-sharing control among the DG such as droop control. MPC is proposed as a primary controller for both mode of MG in this study. MPC predicts the future behaviour of the system model, which is compared with the reference signal to determine the cost function of the system. all the possible switching vectors of the converter are utilized to obtain the cost functions, and the corresponding switching vector, which minimizing cost function is selected to actuate the power converter in the next sampling time interval. Direct power model predictive control is implemented on the inverter for the grid-connected case and Voltage model predictive control is proposed for islanded mode along with Droop control as a secondary controller. This work has been demonstrated and verified in the MATLAB/Simulink environment. The controller effectiveness and robustness has been validated from the Simulations results. Simulation result shows that inverter operates effectively using MPC vii | P a g e Model Predictive Control for Parallel Inverts of Distributed Energy Resource in Micro grid. to deliver anticipated power, voltage and frequency for both operational modes of MG under different load conditions such as linear load, Non-linear load, a step change of load. THE of all cases is less than 3 % for current and Voltage.
