Control system and method for the parallel operation of voltage regulators

摘要

The invention is a system and method for changing the tap position of transformers, where two or more of the transformers are operating in parallel, based on the measured low side bus voltage and low side MVAR flow. A programmable logic controller (PLC) calculates the average low side bus voltage for the transformers operating in parallel. The PLC also calculates a feedback voltage for each transformer as a function of circulating MVAR flow for each transformer operating in parallel based on concept of preventing the tap position of a transformer from exceeding a certain relative difference compared to other transformers.