What is power quality?

The term “Power Quality” means different things to different people. One definition is the relative frequency and severity of deviations in the incoming power supplied to electrical equipment from the steady or fundamental 50 Hz, sinusoidal waveform of voltage or current. These deviations may affect the safe or reliable operation of electrical equipments such as circuit breakers, motors, fans, CNC machines, computers etc.

Power quality Problems
Power quality is affected from both sides of the grid, referring both to the quality and reliability of power as supplied by the utility and to the type and effect of customer loads on the transmission system.
The following are the types of power quality problems

1. Harmonics: It is a distortion of the utility supplied waveform and are caused by “non-linear” loads, which include motor controls, computers, office equipment, compact fluorescent lamps, light dimmers, televisions and , in general, most electronic loads. High harmonics increase the line losses and decrease the equipment lifetime. Total harmonic distortion (THD) measures the degree to which the input is distorted, and is the relative value of all the harmonics combined, as a percentage of the fundamental current.
2. Transients: Commonly called swells, surges and spikes, transients are the most frequent types of power quality problems and often the easiest to fix. The difficulty with transients is in detection since they manifest only as a short-duration change in voltage.
3. Brownouts: These are hours-long voltage sags caused by system overload. These are tending to damage equipment, but such fluctuations are common in developing countries.
4. Reliability: It refers to the probability of maintaining a continuous supply of electricity without interruption.

Power Quality Audit

From surge suppressors, filters and voltage regulators to isolation transformers, power conditioners and motor generator sets, there is a solution for just about every power quality problem imaginable.
The objective of the power quality audit is to determine the source of power quality problems and to devise a solution to that problem. Prior to conducting a power quality audit, we should look at a facility’s unique power needs and then budget appropriately.

Some features of an audit include

DYNASPEDE engineers can complete an on-site power quality audit and make recommendations for commercial and industrial facilities. During the audit, monitoring devices are placed throughout the facility in order to determine precisely where in the system power quality problems are being found, as well as to monitor the quality of the power being supplied by the electrical utility. In general the following are the activities involved in the power quality audit.

• Basic data gathering and analysis
• Review of facility wiring and grounding systems
• Analyze recorded electrical data and utility disturbances
• Provide written recommendations, as necessary

• Power Factor Correction
• Dynamic Sag Correction
• Power Quality Monitoring
• Harmonics filter, static
• Harmonics filter, dynamic

Conclusions

Past five years we are in the field of power quality and energy audit. We have very widely experienced group of engineers and power quality experts, we identify the cause of the problem, design and implement ways and means of minimizing the losses, improving the power quality and achieving energy saving.