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.

The Importance of Equipment Specifications

Introduction

As with any other business or profession, a clear write-up of requirements is important for purchase and procurement. This is especially important for electrical equipment due to the high significance of tolerances, ratings and size.

Whether for new projects or replacements, a specification document is crucial.

Purpose

The chief purpose of equipment specifications is to ensure the purchaser acquires the required equipment, rather than what the supplier thinks is right. You might think that the difference in interpretation is a minor detail. However, considering the detriments associated with wrongly rated electrical equipment, it is vital you get the right specifications.
Do note that suppliers of electrical equipment often serve a wide market and industries, from residential installations, commercial projects to large plants. For this reason, narrow down to your exact niche and area of use. A variable drive for underwater installations may require different requirements from similar equipment for land use due to the prevailing environmental and operating conditions. For example, a simple LV motor operating in desert conditions may require a longer frame size than for cold and windy locations due to extra cooling requirements.

Features
A typical equipment specification consists of the standard equipment rating, and more details based on the options available. Over specifications over the available options is considered impractical and unnecessarily expensive, unless the project is highly sensitive and dependent on the extras. In such cases, the manufacturer may assemble customized equipment, often at a very high cost. The feasible option is to purchase the most suitable options, and then design the power system around the equipment to suit the requirements.
The following are the primary features of equipment specification :
• Crucial requirements based on the market standards
• Desirable requirements based on the available options
• Incidental features based on ‘nice to have’ feature such as equipment color. These features are usually not crucial to performance.

At Artemis Consulting Limited

Format

Introduction: a brief description of equipment installation location, installation type, and nature of the installation environment

Scope Of Supply: a summarized list of the primary equipment constituents, as well as the components to leave out. This reduces chances of misunderstandings during the quotation and delivery
Service Conditions: an in-depth description of the installation conditions including humidity, temperatures, winds, moisture levels and chemical contamination. It can also include a brief description of the indoor or outdoor conditions depending on usage.

Standards: highlights the most appropriate and relevant international norms desired. Ensure that the standards are updated and clearly listed to minimize chances of confusion during quality assurance tests. To be on the safe side, specify the standards to avoid uncertainty due to similar standards depending on region and metric units.
Definitions: misinterpretation is rife when sourcing electrical equipment. It is risky to assume that the manufacturer or supplier is well versed in the industry-specific jargon. Clearly define such terms and phrases in the specification, especially when it has different meanings in different standardizations.

Performance Requirements: clearly state the expected service life of the equipment, both lifetime, and in-between maintenance schedules. Though this depends on the equipment type, it is easy for an engineer to look up and specify the expectations of large electrical equipment such as generators, motors and such. Do note that the mode of operation, as well as the rated duty for LV and MV equipment, usually has a significant impact on the performance requirements; therefore ensure you highlight this factor.

Design Requirements: clearly define the degree of protection required based on the area of usage. Outdoor, indoor and levels of hazards require different design and construction requirements, therefore, highlight this factor. In the same vein, underline crucial fittings such as protective devices, circuit segregation, lifting points, and such. However, ensure that you check out the data sheet first as most of these will already be included.

Inspection and Testing: the purchaser should pay particular attention to this factor, as mistakes are costly. The first test is a physical inspection before purchase. Ensure that you clearly state the required inspections and test before purchase and delivery. To be on the safe side, use international standards as references and acceptable limits for the best results and to save time.

Appendices: contains definitions, and extra information not highlighted in the other components such as noise information, interlocking data and others

Any functioning electrical system, whether SCADA or variable speed drive system is an amalgam of compatible individual elements. With this in mind, approach the procurement with a combination of compatibility and eventual functionality.

ARTEMIS CONSULTING LIMITED

Artemis Consulting Limited is a service based engineering company based in Nigeria but aimed to be recognized worldwide. The service rendered are numerous but it targets is to solve practical engineering problem faced in Nigeria, Africa and global world. Though, Africa itself was known to be facing a lot of problem in Electrical Power system's  Generation, Transmission and Distribution. Artemis will be able to go far more than these issue that we will be discussing here, we will go into the root, Plant design, construction, Installation and Maintenance. What and what are the features to considered as related to the African Power crisis. High voltage and Low voltage in transmission system will also be touched. Under distribution of Power we will be looking at optimization of power distribution, equipment's reliability and disturbance in general. We will also touches base with safety and standard in electrical wiring design and installation. Power system Analysis, control and protection are our target to spread what we know

We are into Project Management too, we will go into that and touches what our local engineers lacks that really affect our infrastructures today, both in Nigeria and Other African countries.

Renewable energy, good. Today the whole world is clamoring for how we can save our world from effect of global warming. Several world conferences headed by United Nation Secretary General Ban Ki Moo and several other has been organised. At this blog we will touch using of renewable energy to replace bad carbon component that continues to shrink our ultimate ozone layer.

This blog is just to useful both for student of Engineering (because Engineering management will be touched), Company owners, Lecturers and any other who is interested in all mentioned above.

You can see we have a lot to do for the next five years or more. There are new innovation in the field we are talking about here which we will love to share with all our readers. Did you hear about new discovery of "Gravitational wave" this is the work of our Mentor Sir, Albert Einstein, there's a lot still going through the study of Relativity theory.

The Scope is just too numerous to touch, 20 years this blog is alive with new innovations and discovery who knows whether we can give birth to our generational Einstein through this blog.

Question for the readers? Who is the first Scientist or Physicist or discover Gravitation?

This is my first Blog, i got know gift for the correct answers (maybe later) but i want to challenge my readers to go more into research and together we can contribute how we can make this world better place to be.

Babatunde Kolawole is my Name.



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