Electrical Power Quality


Electrical Power Quality

Electrical power quality plays an important role in supplying electricity effectively to the consumers. As power becomes more essential and valuable resource for the entire world, it is important to maintain its quality at all levels of usage for reliable working of equipments.

Due to usage of non linear loads and power electronic equipments in power system transmission, distribution and utilization sectors leads to distortion in voltage and current waveforms. We are already aware of the total harmonic distortion by phase control and integral control of AC power. When the wave form of transform power is pure sine wave. so we get good power quality.

What is Electrical Power Quality?

  • Power quality is simply the interaction of electrical power with electrical equipment. If electrical equipment operates correctly and reliably without being damaged or stressed, we would say that the electrical power is of good quality. On the other hand, if the electrical equipment malfunctions, is unreliable, or is damaged during normal usage, we would suspect that the power quality is poor.
  • IEEE has done significant work on the definition, detection, and mitigation of power quality events. IEEE Standard 1100 (IEEE 1999) defines power quality as the concept of powering and grounding sensitive electronic equipment in a manner suitable for the equipment.
  • Electrical equipment susceptible to power quality or more appropriately to lack of power quality would fall within a seemingly boundless domain. All electrical devices are prone to failure or malfunction when exposed to one or more power quality problems.
  • The electrical device might be an electric motor, a transformer, a generator, a computer, a printer, communication equipment, or a household appliance. All of these devices and others react adversely to power quality issues, depending on the severity of problems.

Let’s take example of power quality,

A standard 100-watt light bulb requires 120 volts to produce the designed light output (measured in lumens). If the voltage drops to 108 volts (-10%), the light bulb still works but puts out less lumens and is dimmer. If the voltage is removed as during a power outage, the light goes out. Either a low voltage or complete power outage does not damage the light bulb.

If however the voltage rises to 130 volts (+10%), the light bulb will produce more lumens than it was intended to, causing overheating and stress to the filament wire. The bulb will fail much sooner than its expected design life; therefore, we could conclude that as far as a standard light bulb is concerned, a power quality issue that shortens bulb life is high voltage.

We could also conclude that low voltage or a power outage would cause the lumen output to vary, which effects the intended use of the bulb.

Power Quality Issues,

  1. Flicker
  2. Voltage sags and swells
  3. Harmonics
  4. Grounding
  5. Electrical Transients
  6. Power Factor

If any query or suggestion about Electrical Power Quality  please comment below or Email on sohal@electricalidea.com


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