Hioki PQ3100 User Manual

Appx.4
Explanation of Power Quality Parameters and Events
Appx. 3 Explanation of Power Quality Parameters
and Events
Power quality parameters are necessary to investigate and analyze power supply issues*
1
.
By measuring these parameters, it is possible to assess power quality.
To allow instrument to detect abnormal values and abnormal waveforms, you set the threshold
values. When these threshold values are exceeded, events are generated.
(Threshold values are set based on an estimation of abnormal values, so events do not necessarily indicate
an error.)
Transient overvoltage (Impulse)
Waveform and event
An event caused by lightning strikes, circuit-
breaker and relay contact obstruction and
tripping, etc. Often occurs when there is a steep
change in voltage or when the peak voltage is
high.
Primary fault Close to the source of the break, the power supply of the device is damaged
because of the exceptionally high voltage and this may cause the device to reset.
Event to be detected Transient (A transient of 5 kHz or higher occurred*
2
)
Voltage swell (Surge)
Waveform and event
Mainly occurs under following circumstances and
the voltage rises momentarily.
• Lightning
• Open/close of power line with heavy load
• When switching capacitor bank with large
capacity
• One-line ground fault
• Disconnection from high capacity load
• Voltage surges due to grid-tied dispersed power
supplies (solar power, etc.) during reverse
power supply
Primary fault A surge in voltage may cause the power supply of the device to be damaged
or the device to reset.
Event to be detected Swell
*1: Issues caused by a reduction in the power quality. These issues cause failures of substation equipment
and electronically controlled devices. (Lighting icker, frequent burning out of incandescent light bulbs,
malfunctioning ofce equipment, occasional malfunctioning of machine operations, overheating of reactor-
equipped capacitor equipment, and occasional malfunctioning of overload, negative-phase, and open-
phase relays.)
*2: Measurement band for the transient overvoltage of the instrument is 40 kHz (200 kHz sampling). Use
Model PW3198 Power Quality Analyzer to capture higher-speed transient overvoltage. Measurement band
of Model PW3198 is 700 kHz (sampling: 2 MHz).

Hioki PQ3100 Specifications

General

Brand	Hioki
Model	PQ3100
Category	Measuring Instruments
Language	English