An Accurate Circuit for the Measurements of Multiple Smart Grid Parameters

This paper deals with developing an interfacing circuit for measuring A.C. powers (active, reactive, and apparent power), power factors, and load parameters (resistance, inductance) in a smart grid. The reactive power measurement is an important requirement with the interconnection of various renewable energy sources to the grid. In order to determine the actual value of active and reactive power, the average value quadrature and in-phase components of output are required. Based on the proposed measurement scheme, we obtain an average value of two voltage signals, quadrature and in-phase, which are proportional to the active and reactive power of the system, separately and independently. Mathematical proofs back the proposed method, and the simulation results obtained from LTspice software precisely verify the proposed technique. Experiments were conducted for different inductive loads for the measurement of various parameters. Simulation results show that the maximum error of reactive power measurement is below 1.5%. The major contributions of the proposed method are frequency invariance, cost effective, easy working, least component count, quick response (within a power cycle), and online measurement features.