Pre-charge resistor protection in STATCOMs

Abstract

This master thesis has been done for GE Grid Solutions Oy. The aim of the thesis was to design and implement a new method for protecting the pre-charge resistor in STATCOM systems. Pre-charge resistors can be affected by fault currents, so they need quick protection. These resistors are part of the circuit only during the short pre-charge period. After this period ends, the system bypasses the pre-charge resistors. During the time that pre-charge resistors are in the circuit, they must be protected against any fault that can occur in the system. Protection design has been done through MATLAB Simulink for Advanced Digital Control (ADC) systems, and also settings and configurations for protection relays for the pre-charge period are presented.