Fundamentals and advancements in generator synchronizing systems

Synchronizing a generator to the power system must be done carefully to prevent damage to the machine and disturbances to the power system. Traditionally, power plants include a synchronizing panel to indicate what adjustments the operator should make to the governor and exciter and when it is acceptable for the operator to close the breaker. In many cases, the process is automated using an automatic synchronizer with manual control available as a backup. In power plants with more than a single generator or installations with multiple synchronizing breakers, complicated synchronizing circuits with many contacts are required to switch the voltage transformer (VT) and control signals between the operator controls and the high-voltage equipment. Maintaining proper isolation and safety grounding of sensing and control circuits often requires the use of problem-prone auxiliary relays and VTs. Today, protective-relay-grade microprocessor devices can significantly improve manual and automatic synchronizing systems. This paper discusses how this technology can simplify synchronizing circuits to reduce cost, improve reliability, and easily accomplish complete integration, automation, and remote control of the system.