Why is the Theoretical Calculated Power Factor and Phase Angle Different Than the Measured Values?
- When a single phase is being measured, the WT performs calculations as follows:
Power factor = active power/apparent power (apparent power = voltage x current)
Phase angle = cos-1 (active power/apparent power)
Therefore, the power factor and phase angle of input signals of distorted, DC-offset, or superimposed harmonic component inclusive waves will differ from the power factor and phase angle of the fundamental wave. Also, on other measuring instruments, the measuring or calculation method may differ from that of the WT, so the power factor and phase angle values may also differ.
Additionally, for a power factor close to 0 (phase angle of voltage and current is close to 90°), slight measurement error in the measured values of voltage, current, and power will affect the power factor and phase angle values.
Check that the measuring range is set appropriately, and check that the calculation error attributable to the error in voltage, current, and power is within that range.
- On the WT, the following calculations are used for three-phase three-wire or 3V3A configurations:
Σpower factor = Σactive power/Σapparent power
Σphase angle = cos-1 (Σactive power/Σapparent power)
Therefore, the source of error in the Σapparent power value is the source of error in the value of Σpower factor or Σphase angle. The power factor (value calculated as active power/apparent power) in the case of a distorted waveform is called the total power factor.
The apparent power increases with distortion of the waveform, and the power factor (calculated value) becomes less accurate.
"Phase compensation" (or "power-factor improvement") can be thought to mean, in addition to resolving phase differences in the voltage and current, improving the waveform distortion.
Produtos e Soluções Relacionadas
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.
Analisadores de Potência e Medidores de Potência
A Yokogawa, a maior fabricante mundial de analisadores e medidores de energia e energia, fornece uma ampla gama de analisadores de energia digital para atender a todos os requisitos.