The new Yokogawa WT500 is a compact benchtop power analyser which is ideally suited to the requirements of the alternative energy market.
In particular, its compact size, high speed and accuracy make it attractive to manufacturers of photovoltaic generators, fuel cells and wind generators.
An important feature of the new instrument is its ability to provide a direct indication of sold and bought power in applications where a customer is using a wind or solar generator to supplement the mains power supply. In such situations, the customer may have a contract with the power generation company where they can sell power instead of buying it if they have an excess, and it is important to be able to measure both the sold and bought power.
The WT500 can carry out DC or single- and three-phase AC measurements at voltages of up to 1000 V and currents up to 40 A, and offers a basic voltage, current and power accuracy of ±0,2% and a frequency range of DC and 0,5 Hz to 100 kHz.
The unit measures voltage, current, power and total harmonic distortion with a high update rate, and features a 5,7-inch colour LCD display for showing numerical, waveform and harmonic data. Its three input channels can be set independently to measure different parameters and ranges, making it ideally suited to AC or DC measurements of input/output conversion efficiency.
Optional harmonic measurement functions can be used to measure the harmonic components of the voltage, current and power as well as the normal (total) measurement values. In addition, the RMS voltage and current (the total of the RMS values of all the frequency components in the measurement frequency bandwidth) can be measured simultaneously with the harmonic measurements.
Easily accessed functions include range selection, scaling, synchronisation source, line and frequency filters, update rate, averaging and integration. The WT500 can integrate the active power (watt-hour), the current (ampere-hour), the apparent power (volt-ampere-hour) and the reactive power (VAR-hour). During integration, the measured and computed values of normal measurements can be displayed in addition to the watt-hour, current-hour, volt-ampere-hour, VAR-hour, sold/bought power and integration time.
Other features include user-defined functions, frequency measurement, harmonics setting and delta computation. A remote-control function is also available via the standard USB and optional GP-IB and Ethernet interfaces, while a store function is used to save directly to an external USB memory.