Control of hybrid microgrid
Date of Issue2014
School of Electrical and Electronic Engineering
Nowadays the hybrid micro grid based on the distributed generations is playing a more and more significant role in electricity field with the increasing concerns about the global warming, air pollution and energy crisis. This thesis introduces the basic concept of the hybrid micro grid with its advantages , drawbacks and development in different countries and areas. A simple simulation of hybrid micro grid is configured using MATLAB/SIMULINK. The AC grid is connected to a DC link through a controlled converter. In DC side, PV module is connected to the DC link through a boost converter under MPPT, which makes PV module always operate at its maximum output power. An induction motor is connected to the DC link bus through a controlled inverter under DTC control, which maintains a stable value of flux in IM to follow the change of torque very quickly. The motor can operate as two modes: the motor mode and generator mode. When it operates as generator mode, the regenerative energy will be sent back to DC link through the controlled inverter, causing impact on the micro grid system. The energy storage battery is connected to the DC link through a controlled converter. When the regenerative energy flows back to the DC link, it starts to work and absorbs the additional energy. The simulation on this is to verify the system can maintain its balance and bus terminal voltage or not when it experiences the energy impact from the transition of motor working mode. And the speed of response and the severity of effect of each generative or storage elements for this change are being investigated in this thesis as well. Given the tight deadline, some limits and drawbacks still exist. The simulation of wind turbine is not configured in yet, which also leads to the failure of simulation on two modes transition of system: grid-connected mode and isolated mode.
DRNTU::Engineering::Electrical and electronic engineering