Psychoanalysis

Psychology

Nonlinear distortion

Phasor

Electronic engineering

Engineering

Harmonic analysis

Artificial intelligence

Power (physics)

Transformer

Physics

Nonlinear system

Sine wave

Compensation (psychology)

CMOS

Optics

Quantum mechanics

Electric power system

Voltage

Calibration

Harmonics

Amplifier

Computer science

Metrology

Control (management)

Electrical engineering

Current transformer

Total harmonic distortion

Control theory (sociology)

IEEE Transactions on Instrumentation and Measurement

This paper aims at characterizing and improving the metrological performances of current and voltage instrument transformers (CTs and VTs) in harmonic measurements in the power system. A theoretical analysis is carried out to demonstrate that, due to the iron core nonlinearity, CT and VT output signal is distorted even when the input signal is a pure sine wave. Starting from this analysis, a new method for CT and VT characterization and compensation is proposed. In a first step, they are characterized in sinusoidal conditions and the harmonic phasors of the distorted output are measured; in the second step, these phasors are used to compensate the harmonic phasors measured in normal operating conditions, which are typically distorted. The proposed characterization and compensation techniques are called SINusoidal characterization for DIstortion COMPensation (SINDICOMP). Several experimental tests, using high-accuracy calibration setups, have been performed to verify the proposed methods. The experimental results showed that the SINDICOMP technique assures a significant improvement of CT and VT metrological performances in harmonic measurements.

Compensation of Nonlinearity of Voltage and Current Instrument Transformers