Power analyser has basic accuracy of 0.01 per cent
Transformer manufacturers can benefit from cost savings, using the WT3000E Transformer Version power analyser, says Yokogawa. It is, says the company, the world’s most accurate power analyser dedicated to transformer testing, with basic accuracy of 0.01 per cent.
The WT3000E Transformer Version is dedicated to testing the power transformers used in the power utilities’ transmission and distribution sectors. Accuracy is 0.5 per cent at power factors as low as 0.01 at 100V and 1.0A, making it suitable for precision testing of transformer losses, allowing transformer manufacturers to avoid potential fines imposed by power authorities that could run into thousands of euros.
As every kW lost beyond specified limits can cost thousands of dollars in fines, it is vital to have confidence in the measurement of power losses, particularly under no-load conditions and at power factors as low as 0.01. Therefore the WT3000E Transformer Version is calibrated at power factors of 1, 0.5, 0.05, 0.01 and 0.001 to enable engineers in transformer testing to accurately capture and measure any drift outside the limits described in the IEC60076-8 Standard. It exceeds the requirements for accuracy in the standard at a power factor of 0.01 and is also specified down to a power factor of 0.001.
The analyser maintains high levels of accuracy over a range of power factors, says the company. The ±0.01 per cent total power accuracy figure applies at a power factor of one and a frequency of 44 to 66Hz. The corresponding value for power factors in the range 0.02 to 0.01 is 0.5 per cent, and for power factors in the range 0.01 to 0.001 it is seven per cent.
The analyser is stable, offering consistent results time and time again without the need for yearly adjustments, claims the company. Every instrument is supplied with a calibration certificate from the company’s ISO 17025-accredited calibration laboratory in the Netherlands. The company is the only ISO 17025-certified, non-governmental organisation that offers calibration up to 100kHz, enabling it to guarantee the specifications of its power meters and improve them with calibration.
The analyser has an intuitive 8.4inch, high-resolution TFT display which can be used to compare up to four waveforms in split-screen mode with clear safety and overload indicators.Measurement ranges are optimised to match the potential and current parameter values used in the transformer industry. It also enables users to measure harmonics and distortions while simultaneously measuring power. It can analyse and display a waveform’s individual frequency components, and check signal components other than the integer multiples of the fundamental wave.
User-defined triggers can be set to capture readings that satisfy or fall outside user-defined conditions. Users can also define and use up to 20 custom computations.
Delta computation, provided as a standard function, allows calculation of individual phase voltages from line voltages measured in a three-phase/three-wire system. Cycle-by-cycle trend analysis is included as a standard feature. It allows users to list voltage, current, active power and other parameters for each cycle. Direction sensitive energy measurements are also enabled, with the facility for the integration of instantaneous values for positive and negative readings.
The instrument is supplied with free application software which is used to read numeric, waveform, and harmonic data through a communications interface such as GP-IB, USB or Ethernet.