A New Central Control Scheme for Future Micro-Grid Systems Considering Variable Speed Drive Systems and Fuzzy Logic Control System

Variable Speed Drive Systems Consist of

• •

  The rectifier.

• •

  Dc- link.

• •

  Inverter.

• •

  Motor.

• •

  The connected mechanical load.

The Harmonics Amplitude of VSDs is Determined by

• 1.

  Drive scheme (number of pulses, type of rectifier).

• 2.

  The percentage of the VSDs capacity to the total the power system's capacity.

• 3.

  The short circuit power of the feeding system.

• 4.

  Electrical insulation state for driving system.

• 5.

  The electrical load of the VSD_S.

• 6.

  Keeping VSDs voltage constant.

This research aims to compare the control strategies which used to ensure the required bias voltage to operate the four-quadrant transistors added to the DC - link of the VSDs and select the best strategy to reach the high-power factor and lower losses during the phase of smoothing.

This work focuses on achieving the basic requirements of the automated operations required for high performance. Both small size and low weight of the drive and control circuits with chopper circuit are very suitable for integration with VSD_S. This integration doesn't require major changes in both power and control circuits, and helps chopper to be integrated with any existing system by adding some simple modifications.