Position angle transducer for tap changing transformers

Abstract

A position angle transducer for voltage compensating tap changing transformers provides secondary tap number or tap position analog output signals which accurately reflect the secondary tap position even if a non-linear relationship obtains between the shaft angle and tap number. A shaft angle sensor generates shaft angle analog signals and an analog-to-digital converter converts the shaft angle analog signals to shaft angle digital words. A digital-to-digital converter receives the shaft angle digital words and provides at its output tap number digital words according to the transfer function or functional relationship of tap changing shaft angle to tap number for the particular transformer. A programmable read-only memory performs the digital-to-digital conversion and is flexibly programmed according to the transfer function of the transformer and in order to establish any desired transfer functional relationship. The tap number digital words may then be converted to tap number analog signals at the output truly representative of the secondary tap position for input to a utility company SCADA System.