TOP 10 Power Quality Problem

Around the globe, we all know the effect of fine, cleaned electrical power system, you'll all agree is positive, it contribute a lot that we can't mentioned here, if we have to focus on these positive effects, part by part, sector by sector and in all ramifications, 1000 pages of books will be birth,still, we will have more area untouched. In Africa generally, i believed most people especially in rural area are naive towards quality of Electricity they are use to, all they are interested "Let there be light and it is" by switching on light. The Quality, process, Transmission and even billing is not of interest. We are here to touch top 10 electrical power quality problems. We will love you to share it all...

Before we move on to the top 10 power quality problems, let us first understand what power quality is, and why it has become the most vulnerable issue pertaining to power supply in the recent years.

Power Quality: It can be defined as a measure of voltage parameters that synchronize with the phase and allow electrical systems and equipment to function normally without causing any loss to their performance and durability. Simply put, power quality is a factor that determines how fit and safe the electricity is, from a consumer’s point of view.

Why it has become the most vulnerable issue?
Though, power quality has been an issue with electrical power since it was invented, it has become a very popular issue in the recent years. This is because, most of the data losses,, Electrical Machine stalls, equipment's failure, computer reboots and malfunctioning of the electric devices are due to inferior power quality.

The following are the top 10 power quality problems ranked according to their impact on electrical systems and devices, with first one being the most vulnerable cause:

1.Voltage Sag

Explanation: This is the most common problem in which voltage drops from 10 to 90% of the normal power frequency voltage. This may last up to one minute.

Consequences: Malfunctioning of computers, IT equipment, electro-mechanical relays and electric rotating equipment, etc.

Appropriate solutions: Using voltage regulators, power conditioners, uninterrupted power supply systems can prevent the above mishaps.

2. Short Interruptions

Explanation: Short interruptions occur when power supply is completely nullified for a few milliseconds, and sometimes, up to two seconds.

Consequences: Protection devices get tripped, inefficient data processing or loss of data, sensitive electric equipment may stop (PC’s, ASd’s, etc.)

Appropriate solutions: Using power conditioners and uninterrupted power supply systems can prevent the above mishaps.

3. Long Interruptions

Explanation: Long interruptions occur when power supply is completely stopped for more than two seconds.

Consequences: All electric equipment stop functioning.

Appropriate solutions: Using Gen sets, Power generators, solar inverters, electric home inverters, etc., can provide temporary solutions.

4. Voltage Spike
Explanation: This takes place at a lightning speed. A sudden spike in the voltage may occur due to lightning strikes, during thunderous storms or due to sudden connection/disconnection of heavy loads from the mains. These spikes generally last only for few microseconds.

Consequences: Destruction of highly sensitive components such as microprocessors, insulating coils. Can also cause electromagnetic interferences (EMI’s).

Appropriate solutions: Voltage regulators, UPS can save your electric equipment from low to medium voltage spikes.

5. Voltage swell
Explanation: Voltage swell is defined as a brief increase in the voltage for a few seconds. This is generally caused due to defective transformers, inefficient power sources or sudden operation of heavy loads.

Consequences: Lights and screen displays flicker, data loss, sensitive equipment may stop or get permanently damaged.

Appropriate solutions: Voltage regulators, power conditioners and UPS can prevent your devices from voltage swell.

                                                     

6. Harmonics

Explanation: Harmonic distortions are associated with both voltage and current waves in the sinusoidal form. Though voltage harmonics are present, most of the harmonics are caused as a result of current distortion. And prominent electric distortion takes place due to the presence of variable electric loads on the power system, also known as non-linear loads.

Consequences: Increased resonance, overheating of equipment as well as cables, EMI’s, tripping of protectors, etc.

Appropriate solutions: Using passive filters, active filters (costly option), delta-wye transformers, k-rated transformers can prevent different types of harmonic distortions. Also, increasing the size of conductors can help reduce impedance and thus the harmonic distortion.

7. Voltage Fluctuation

Explanation: Arises due to oscillations in voltage value and amplitude, when modulated by signal waves having frequency less than or equal to 30 Hz.

Consequences: Lights and screen displays flicker, data loss

Appropriate solutions: You can avoid voltage fluctuations using voltage regulators or power conditioners.

8. Noise

Explanation: Noise comes into picture when the frequency of a power system is superimposed by signals having higher frequencies.

Consequences: Simple disturbances in IT and electronic equipment (no serious damage occurs)

Appropriate solutions: Noise can be reduced using proper bypassing ad filtering techniques.

9. Voltage Unbalance (VU)
Explanation: Voltage unbalance is a result of frequency variation in a three phase power supply which arises due to unequal differences between the phase-angles of the three respective voltages.

Consequences: As a result negative sequence may be inducted into the system which can be harmful to the phase loads (most vulnerable equipment in such cases is, three phase induction motor).

Appropriate solutions: Using PWM converter as a STATCOM controller or as an active filter can reduce voltage unbalances considerably.

10. Brownouts
Explanation: Brownout is a continuous low voltage power supply state. It occurs sparingly in summers (or when the demand of power outweighs the supply).

Consequences: Inefficient data processing or loss of data and malfunctioning of electrical equipment.

Appropriate solutions: Voltage regulators, UPS and power conditioners can save your electric equipment from brownouts.

Conclusion

Since the invention of electricity, there have been problems regarding power quality. Many measures were taken to control loss of power when distributed over long distances, such as attenuation and polarization. Unfortunately, even now, the problem persists.
However, one can reduce; if not entirely eliminate the power quality problems, with the above mentioned electric equipment as a solution for each problem.