Measurement of Inverter Efficiency

Measuring Efficiency with High Precision: Simultaneous Measurement of Input and Output
Achieve precise measurement of inverter efficiency by simultaneously measuring input and output power.  For accurate measurements of power converters, it is necessary to measure DC power and AC power with the same timing. The WT5000 provides up to seven input elements capable of simultaneous measurement for single-phase input/three-phase output or three-phase input/three-phase output.

Accurate Measurement of Fundamental PWM Voltage Waveforms
Evaluating inverter drive motors involves accurately measuring the fundamental component of voltage. Typically, the mean is used for measuring sinewave-modulated PWM waveforms because the voltage MEAN (rectified mean value calibrated to RMS value) closely resembles the fundamental voltage component.

However, motor drive technology has become more complex in recent years; pure sinewave-modulated PWM is less common, and cases in which the voltage mean differs greatly from the fundamental voltage waveform arise frequently. With the harmonic measurement function of the WT5000, accurate measurements of commonly measured values such as active power and the fundamental or harmonic components can be taken simultaneously without changing measuring modes.

Phase Voltage Measurement Without a Neutral Line
The delta computation function of the WT5000 enables phase voltage measurement in three-phase three-wire configuration without a neutral line, allowing calculation of each phase voltage separately.

Achieving Higher Precision: Instrument Loss Correction Function
Instrument loss caused by the input resistance of the measuring device is, in principle, an unavoidable problem. Yet you can overturn conventional wisdom and obtain higher measurement accuracy by compensating for any potential instrument loss in the measured values.

Synchronizing Measurements
When measuring three-phase input/three-phase output using a three-phase four-wire system, you can achieve accurate efficiency measurement by synchronizing two wattmeters. This setup ensures accurate measurement of input power and output power and efficiency with minimal complexity.