The WT3000E is an enhanced version of Yokogawa’s WT3000 precision power analyser. The specified 45 to 65Hz accuracy for the WT3000E is 0.01% of reading plus 0.03% of range. These figures are based on RMS values rather than waveform peak values. Because power ranges are the multiple of the voltage and current ranges, the actual power measurement error due to an uncertainty of 0.03% of range in a WT3000E is less than 0.01% of range for a power meter based on peak values.
These accuracy levels are important for testing devices such as solar inverters, which are already working at overall efficiencies of 90-96%.
To increase the efficiency, even by a few decimal points, is a challenging and important goal for the manufacturers, and the power analyser provides the necessary levels of precision to truly confirm even the smallest improvements in efficiency.
The focus on sustainable and renewable energy has also raised the importance and need for manufacturers to comply with IEC standards during their product development.
The instrument provides the flexibility to mix 30 and 2A input current elements, which enables users to test the compliance of their products with today’s harmonics, flicker and standby power standards in a single instrument.
Like other models in the WT3000 Series, the enhanced power analyser has a variety of alphanumeric and graphic display formats, including the ability to display the input signal as waveforms for easy analysis.
It also offers high-speed data updating which allows users to capture fast-changing transient signals with high precision. Further analysis can then be performed using the captured data.
The analyser also includes as standard two features previously only available as options: delta calculation and cycle-by-cycle analysis. The delta calculation function allows users to calculate individual phase voltages from the line voltage measured in a 3-phase/3-wire system: an important feature for determining the phase voltage in applications such as motor testing where there are no neutral lines.
Cycle-by-cycle analysis enables users to list the measurement parameters such as voltage, current and active power for each cycle in a time series. Input frequencies from 0.1 to 1000Hz can be measured, and up to 3000 items of data can be saved in .CSV format.
In addition, by using Yokogawa’s free WTViewerEfree software, users can graphically display the data by cycle: a unique method of capturing fluctuating transient power with high precision.
The accuracy and precision of Yokogawa instruments is verified by tests carried out at the company’s European standards laboratory at its European headquarters in The Netherlands. This facility is the only industrial (i.e. non-government or national) organisation in Europe to offer traceable power calibration, to national and international standards, at frequencies up to 100kHz: a requirement for higher harmonic measurements specified in quality standards such as ISO9000.
“The focus on renewable energy and the need to optimise efficiency and comply with international power quality standards is placing ever greater emphasis on the importance on high-quality measurements”, comments Terry Marrinan, Yokogawa’s Vice President, Test & Measurement, for Europe & Africa: “As the world’s most accurate power analyser, the WT3000E provides the necessary levels of precision to carry out these measurements, giving R&D engineers an enhanced tool that is not only the benchmark for energy efficiency measurement but also a reference for calibrating power measuring instruments in standards laboratories.”