Why Does the Measurement of Inverter Efficiency Exceed 100%?

This could be caused by any of the following:
  1. Is there any crosstalk (especially around the 2nd order)?
  2. Are there any effects of CMRR (especially around the 2nd order)?
  3. Is the location of measurement immediately next to the inverter I/O?
  4. Is the measuring lead too long?
  5. There are cases where switching the measuring lead from shielded cable to twisted pair can reduce the influence of noise.
  6. It is best to keep the measuring leads away from the ground or reference potential (to prevent capacitive coupling with the GND).
  7. If using a CT, there are cases when you should disconnect from ground.
  8. Is the input too small relative to the rating of the PT or CT current sensor?
  9. Is the combination of PT, CT, or current sensor and power meter range appropriate?
  10. Is the sync source setting the same for all inputs (the setting can be unified on the WT1600 and PZ4000)?

Related Products & Solutions

Precision Power Analyzer WT3000

With 0.02% accuracy and 1MHz bandwidth, the WT3000 delivers where the highest precision measurements are required. It is the industry standard for R&D work on inverters, motor drives, lighting systems and electronic ballasts, UPS systems, aircraft power, transformer testing, and other power conversion devices.

PZ4000 Power Analyzer

The PZ4000 is designed for High Frequency Power Measurements as well as Transient Power Measurements. Its real-time acquisition system can perform cycle-by-cycle power measurements. One to Four input elements offer Basic Power Accuracy of 0.2% with 2 MHz Bandwidth and 5MS/sec digitizing rates.

WT1600 Digital Power Meter

The High-end WT1600 is designed for a wide range of applications, from energy-saving to large load applications. The WT1600 has a six element input capability to provide maximum flexibility, and Basic Power Accuracy of 0.1% with 1 MHz Bandwidth.

WT1800 High Performance Power Analyzer

The WT1800 Power Analyzer offers maximum flexibility with up to six wattmeter elements, high bandwidths, simultaneous high speed digitizing, and wide voltage and current ranges. Although this model is still available, the newer WT1800E offers higher accuracy.

Power Analyzers and Power Meters

Yokogawa, the world's largest manufacturer of energy and power analyzers and meters, provides a broad choice of digital power analyzers to satisfy all requirements.