Load Compensation in Three Phase Power Systems

Diplomarbeit, die am 04.11.2002 erfolgreich an einer Fachhochschule in Deutschland im Fachbereich Elektrotechnik eingereicht wurde. Abstract: The object of this thesis is to design software and hardware to obtain the device parameters of a compensator. This compensator should restore the balance and the power factor of a three-phase three-wire system by using reactive elements only. The derived parameters should be accessible remotely and displayed on a PC. L. S. Czarnecki recently presented a highly respected approach to derive the device parameters of the compensating susceptances. He defined the admittances Ye and A which represent the conditions in a three-phase system. He also suggested a way to derive these susceptances by measuring two line-to-line voltages and two line currents. The load balancing technique used in this project was based on Czarnecki's approach. The first phase of the project concentrated on understanding and proving the theory behind the project by means of computer simulation. The second phase of the project involved writing software for the DSP and building an interface to successfully task the requirements set by the theory. The aspect of being able to transfer the data to a PC via a modem-to-modem connection was taken into account too. In the final stage it is shown that the implemented system is able to derive the necessary parameters in order to balance the currents and restore the power factor as supplied from mains. It was found that even though the supply from the University of Cape Town does not meet the requirements of the theory in terms of harmonic distortion, it is possible to achieve sufficient load balancing and power factor correction. It was not possible to establish a reliable connection from one modem to the other because of the limitations of the telephone exchange system used at the University of Cape Town. The parts that are necessary for communication, however, we