Design and implementation of a new onload voltage regulator for power distribution systems

Abstract

This work is part of a research project whose aim is to develop a non-conventional onload voltage regulator (VR) so as to overcome the operation technique that have yet been performed on 13,8kV distribution buses. The proposed device has as main characteristic a microcontrolled electronic circuit that acts on the load voltage through nine regulation taps. It presents a good response speed, since the regulation is performed within a short time period limited in four cycles of the electrical frequency. Each step of regulation provides with 5% variation on the rated load voltage, establishing a wide control for values between 70% and 110% of the voltage supplied. The design is made up with a modified magnetic unit (autotransformer) using electronic taps (thyristor switches). It also includes an intelligent electronic control and transmission of pulses through optical fibers for SCR firing. The global system is presented under a modular structure and the experimental results confirm the functionality of the electronic VR for many load types.