Electronic circuit for the multi-phase measurement of electrical energy and power

摘要

To form a product sum <IMAGE> of electrical quantities ai and bi with the aid of a single multiplier circuit path, the signals ai and bi are modulated with signals ci. The modulated signals are added to form sums <IMAGE> from which the multiplier forms the product S'*S". The characteristics selected for the signals ci are such that when the average is formed over time, products having unequal indices cancel each other and thus the equation S = S'*S"/(C*C) holds true.