Why Does the Measurement of Inverter Efficiency Exceed 100%?

This could be caused by any of the following:

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

PZ4000设计用于高频功率测量以及瞬时功率测量。此仪器的实时采集系统可执行按周期的功率测量。一到四个输入单元提供0.2%的基本精度，具备2MHz的带宽和5MS/秒的数字化速率。

高端WT1800是WT1600的升级产品，可应用于从节能到高负载应用在内的各种应用领域。WT1800拥有6单元输入能力，可提供最大的灵活性和5MHz带宽下0.1%的基本功率精度。

WT3000高精度功率分析仪提供最高精度的测量。此产品已成为行业标准，用于变频器、电机驱动器、照明系统和电子镇流器、UPS系统、飞机电力系统、变压器测试和其它电力转换设备的研发。WT3000的基本功率精度达0.02%，带宽为1MHz。

功率计或称瓦特计，可以测量产生、转换或消耗电能的设备各项特征，包括设备的各项参数，如：功率（瓦特）、功率因数、谐波和效率等等。

YOKOGAWA数字功率分析仪，性能优越、测量可靠，支持各种应用，非常值得拥有。尤其是YOKOGAWA WT300E功率计，在全球功率计市场上口碑与地位日益跃升。