MYSTERIOUS CORONA EFFECTS IN TRANSMISSION LINES

Fig-Corona Effect in Transmission Line Visible at Night

What Are Corona's effects on electrical energy transmission lines?

If you look along the high voltage power transmission line in a clear sky at night, you will observe the dreamiest violet glow phenomenon embedded with hissing noise along the transmission line conductors. This indefinable phenomenon causes nothing but a production of ozone gas surrounding overhead electrical energy transmission lines known as the Corona or Corona effect.

Finally Carbon Dioxide can be Removed widely from Factories and Power Plants

Power Plant Releasing Carbon Dioxide into Atmosphere

A group of scientists finally found a way to capture and remove the carbon dioxide gas significantly from industries and power plant gas that is released into the atmosphere.

Scientists at Waterloo University created a powder that can capture the Carbon-di-Oxide (CO2) from industrial or power plant gas more efficiently than the conventional way.

WHAT IS THE MAJOR ENERGY SOURCES FOR ELECTRICAL POWER?

This article will help you to understand the basic concept of Energy, Energy sources and How different forms of energy change to electrical energy. In the below link, you will get a pdf copy were briefly described-

Importance of Electrical Energy;

Generation of Electrical Energy;

Sources of Energy;

Comparison of Energy Sources;

Units of Energy; 

Relationship Among Energy Units;

Efficiency;

Calorific Value of Fuels;
Advantages of Liquid Fuels Over Solid Fuels, &

Advantages of Solid Fuels Over Liquid Fuels.

Sponsored:

Basic Concept of Energy: 

We are surrounded by Energy.  Energy is everywhere and it surrounds us; but we can’t touch it and also can’t measure its mass, because it is massless. However, we can see and feel the effects of energy on many materials. The word energy came from the Greek Energeia, meaning in or at work.

Energy is the ability or capability to do work; Energy cannot be created or destroyed.

We cannot create or destroy any energy, for our use we only can change the form or state of energy from one into another.

In the language of physical science, energy means the ability or capability to do work.  Work means a change in position, speed, state, or form of matter.  Therefore, energy is the capacity to change matter.

According to the law of conservation of energy, the total energy of a system remains constant, though energy may transform into another form. Two billiard balls colliding, for example, may come to rest, with the resulting energy becoming sound and perhaps a bit of heat at the point of collision.

In fact, everything that happens in the universe, from the eruption of volcanoes to the sprouting of seeds, to the moving of people, takes energy.  When we turn on a motor, drive a car, cook on a stove or switch on a light, we are using energy.

Energy calculation:

The amount of energy is directly proportional to the mass of the body:

E= mC2

where,

m  is the mass,

c  is the speed of light in a vacuum,

E  is the rest mass-energy.

Generation of Electrical Power

The conversion of energy available in different forms in nature into electrical energy is known as the generation of electrical energy or electrical power. Energy is available in various forms from different natural sources such as pressure head of water, the chemical energy of fuels, nuclear energy of radioactive substances etc. which usually changes into electrical power in different ways.

Electrical energy is superior to all other forms of energy due to the following reasons:

1. Convenient form;
2. Easy control;
3. Greater flexibility;
4. Cheapness;
5. Cleanliness;
6. High transmission efficiency.

The major sources of electrical energy is as below:
(I) The Sun
(ii) The Wind
(iii) Water
(iv) Fuels
(v) Nuclear energy

Energy exists in different forms in nature but the most important form is electrical energy. Modern society is so much dependent upon the use of electrical energy that it has become a part and parcel of our life.

Download the full pdf copy

DOWNLOAD

Sponsored:

Underground Power Cable: Environment and Health Issues

Power Plant Cooling Tower

Impact of Power Cable Uses in Environmental and Human Health:

Technology changing every day, every moment! High voltage electricity transmission underground cable system also taking over instate of the overhead power line. Though underground high voltage electricity transmission more technically challenging and expensive than installing overhead lines; but to get enough space for an overhead line, especially in an urban area is very difficult now. So, it’s the demand of time for the underground cabling system. Of course, we have to keep in mind the potential impact on the environment and the health of cable installations.

The overhead conductor is more harmful to human and other animals than underground cables.

When a vehicle is parked under a high voltage transmission line an electrostatic field is developed in it. When a person who is grounded touches it a discharge current flows through the human being. In order to avoid this parking, lots are located below the transmission lines the recommended clearance is 17 m for 345 kV and 20 m for  400 kV lines.

EFFECT ON ANIMALS

Many researchers are studying the effect of the Electrostatic field on animals. In order to do so, they keep the cages of animals under a high Electrostatic field of about 30 kV/m. The results of these Experiments are shocking as animals (are kept below high Electrostatic field their body acquires a charge & when they try to drink water, a spark usually jumps from their nose to the grounded Pipe) like Hens are unable to pick up grain because of the chattering of their beaks which also affects their growth. 

EFFECT ON PLANTS

High power transmission lines affect the growth of plants.

Physiological parameter was primarily due to the effect of reduced cell division and cell enlargement.

From various practically study it was found that the response of the crop to EMF from 110 kV and 230 kV Power lines showed variations among themselves. Based on the results the growth characteristics like shoot length, root length, leaf area, leaf fresh weight, specific leaf weight, shoot/root ratio, total biomass content and total water content of the four crop plants were reduced significantly over the control plants.

SHORT TERM HEALTH PROBLEM

• Headaches.
• Fatigue.
• Insomnia.
• Prickling and/or burning skin.
• Rashes.
• Muscle pain

LONG TERM HEALTH PROBLEM

• Risk of damaging DNA.
• Risk of Cancer.
• Risk of Leukemia.
• Risk of Neurodegenerative Disease.
• Risk of Miscarriage.

Insulating in Overhead Power Line and Underground Cable:

Conductors, no matter they are overhead or underground that transmit electricity must be electrically insulated. But there is one major difference between overhead lines and underground cables is the way they are insulated. Overhead lines are insulated by open-air surrounding conductor whereas underground cable conductors are fabricated wrapped in layers of insulating material.  Air insulation is the simplest and free from nature for overhead current-carrying conductor. Air also flow through the bare overhead conductors and remove the produced heat. On the other hand for cable system, conductors are buried into the ground which high-quality insulation is required to withstand the very high voltage. Produced heat dissipation into the environment for underground cable conductor and their surrounding insulation in different installation method is a major issue for impact on nearby flora and fauna.

Technology for Cable Insulation System:

Fluid filled or Gas Insulated Cables: Mainly the first generation cables are fluid-filled, in these cables insulation is provided by paper, impregnated with fluid or insulated oil under pressure, wrapped around the central copper conductor. Lead or Aluminium sheath uses to cover this paper layer and to prevent corrosion of the sheath PVC, MDPE or HDPE outer the jacket is used.

Alternatively gas insulation lines are used for insulation where Aluminium conductors are supported by insulators contained within sealed tubes which are pressurized with a Nitrogen or Sulphur Hexafluoride (SF6) gas to provide the main insulation. The main advantage is that SF6 is a greenhouse gas and the system is cost benefit for sealing end system.

XLPE Insulated Cables: As a result of change and advance in cable technology fluid-filled cables are moving back and XLPE cables are coming at the front everywhere. In these smart cables, the core conductor is insulated by XLPE means Crossed Linked Polyethylene material. It requires less maintenance and no auxiliary fluid equipment to monitor and manage for XLPE cables.

Underground Cable Installation Methods, Requirement and Impact:

For high voltage or extra high voltage underground cable installation mainly three types of method are following:

Direct Buried;

Deep Tunnels;

Surface or Trench.

Direct Buried is the traditional method for high voltage cables installation system where trenches are approximately 1.5m wide and 1.2m deep for each circuit. To maintain the rated current carrying capacity of cable thermally stable backfilling is required with properly graded sand. Space required for cable easement corridor: 20m – 40m, 55m width; Joint bays intervals:  500m – 800m; working space required for join bays, power roller for excavating cable trench, sand bed, backfilling material, handling cable drum in site etc.

Deep Tunnel is generally used in urban locations where direct bury installation would cause unacceptable disruption. Typically 4m and 12m for joint bay diameter depth of a tunnel around 25m to 30m and maintains proper slope to provide free drainage. Two head house buildings order of 16m x 16m x 7m high require for maintenance and for installation of the cables at each end. A cooling and ventilation system and rail-mounted access vehicle is required for emergency exit, inspection, maintenance and repair. River or railway crossing can be made in this system.

Surface or Trench is excavated and is constructed concrete trenches where cables are laid directly within the trench which is capped with reinforced concrete covers laid flush with the ground surface. Surface or trench are used in urban situations or and within the substation compounds needed to take reduced land.

Environmental Impact on Underground Cable Installation:

The major environmental issues associated with the installation of direct buried or cut and cover tunnel cables are the disruption to traffic, noise, vibration, visual intrusion and dust generation and deposition due to the excavation of trenches along the route. Heavy goods vehicle traffic will also be generated by the work, cable crossing major roads, removing spoil and bringing in plant and materials, including backfill, to trenches. About 30m x 80m land area required for each circuit of high voltage cable sealing end compound and a significant space required for a terminal tower construction.

Nearly all installations require joints at specific intervals along the route and joint bays maybe 30m to 40m in length and 5m in width. The majority of the jointing accessory assembling is carried out on site. Sometimes cooling system pipe is laid alongside cable and pumping equipment and heat exchangers are required above ground and these must be sited which cause noise on the locality. Direct buried cable produce heat which harmful for on and near vegetation and insects.

EMFs or Electric and Magnetic Field Effect of Underground Cable:

The conductor which energized or having the presence of voltage there is electric field present surround it, when current flow continues magnetic field also present there surround the conductor, this mainly happens for the overhead electric line. But underground cable able to eliminate its electric field totally as it is screened out by the sheath around the cable; but it still produces magnetic fields. EMFs field strength is stronger to the centre of the field or near to the conductor and gradually weakened at the outer point from the centre. In a general sense overhead line is farther than an underground cable to human, so it should overhead line is safer than an underground cable. However, as the individual cables are installed much closer together than the overhead conductors which result in the magnetic field from cables falling more quickly with distance than the magnetic field from overhead lines. The overall result is that the cable produces a lower field than the overhead line; means the EMFs effect is smaller for underground cable than the overhead line.

WHY NEEDS REDUCE ELECTRICITY USAGE

Why Need Reduce Electricity Use in Our Daily Life?

If anyone asks- why need to reduce electricity use in our daily life? Yes, in simply reduce electricity use every day to save money as electricity bill. For your individual interest, if you reduce uses electricity, end of the monthly electricity bill will come less and you can save money.

Reduce Electricity Use and Costs

As a citizen of a developing country like Bangladesh, if you reduce or limit your electricity using then your more neighbours will get a chance to use electricity, because the production or facility of electricity here is not created yet for all. Only a finite amount is available at any given time, when some people usage extra electricity as unnecessary AC’s or fans, there sometimes isn’t enough power to go around. As a result, sometimes there are rolling blackouts knowing as “Load Shading”.

When the time comes to replace your appliances, consider buying more modern ones, with more energy-efficient systems. In the United States, a Department of Energy program called Energy Star identifies the most efficient appliances in each category.


The average yearly energy consumption of a 10-year-old refrigerator is 651 kWh. If you get a new, energy-efficient model, according to Energy Star’s “Flip Your Fridge” calculator, you’ll save $144 over five years, as well as 411 pounds of carbon pollution.

Reduce Electricity Use and Save Environment

As a global citizen, you can play a vital role in environmental impact just by using reduce electricity in your daily life. A significant amount of fuel energy is using to generate electricity worldwide. A huge amount of gasoline, diesel oil, coal etc. are using to generate electricity which is the cause of a direct negative impact on the environment. Some developed countries are using bio-fuel to reduce carbon footprint, to do this they actually using huge animal and human food; on the other side of the world, a large number of people are not getting their minimum food every day.

friends, you love your neighbour’s needs, your environment; hope these answers are good enough for the question “why reduce electricity use?”.

Don’t believe in Electricity Myth

Reduce Electricity Usage before Launch a New Project

It’s not enough to put off the switches of extra appliances, we should think and rethink before starting a new project- what is the alternate and or environment-friendly energy source be used? Say for a new or expanding housing project: the authority should have to undergo an environmental impact looking on electricity and other utilities.




Using the latest smart technology and energy management technique is possible to provide customers to use reduced energy programs. This program may charge the consumer the actual cost using energy at higher prices during peak-hour (high demand time) and lower costs during off-peak-hour (less demand time). If it’s possible to shift energy use time from peak-time to off-peak-time then easy to save energy, which means money; for example- you can easily shift your programs such as running water pump, washing machine, dishwasher, ironing clothes and so many.

Reduce Electricity Bill without any Cost


You can reduce your monthly electricity bill without any cost just following some rules of practices, like as below:




Keep your air-conditioner vents open and clean, it will consume less electricity;

Promote better airflow in your home to reduce electricity consumption;

Stop using heat for your laundry machines whenever possible and pack the right amount of cloth;

Operate your Dishwasher, Heater and Laundry machines at night (off-peak-time);

Load your Dishwasher and Laundry and other appliances and electronics with the right load and efficiently;

To help reduce their peak power demands and save money, many utilities are introducing programs that encourage their customers to use electricity during off-peak hours. The programs pass on the savings to you, the customer, through rebates or reduced electricity rates.




Keep your appliances unplugged rather than standby to reduce your phantom load.




If you want to know more details about energy saving procedures visit other post like:

ENERGY-SAVING TIPS FOR YOUR HOME APPLIANCES

Finally, we can conclude as reduce electricity usage is not only for saving money but also for our environment. It’s not an issue for developing countries, it’s an issue for developed countries too. So, please come help to go green for all.


Don’t forget to share your knowledge, please!!

WHAT IS THE EQUIPMENT CLASS AS PER INSULATION GRADE

The Equipment Classes Considering the Insulation Level to Protect Electrical Shock

It is almost impossible to go the end of a list where electricity is necessary in our life today, and we everybody will agree that electricity is the closest friend in our daily-life.

Yes, electricity is very close friend and helping us every moment; but don’t forget, it will make no mistake to injure you even to kill by shock if you are not alert before it getting the chance.

Bearing in mind the electrical shock, a safety measure must ensures in our electricity operated home appliances and equipment. Electricity shock protection procedures are different depending on the tentative shock level.

Considering the electric-shock preventive insulation level the equipment are classified on three types as follows:

• Class-I Equipment;
• Class-II Equipment;
• Class-III Equipment.

Class-I Equipment

The electrical equipment which includes a means for connection of Exposed Metallic Parts (EMP) of the equipment to the Earth Conductor (EC) to provide protection against electric shock in case of failure of the basic insulation of the equipment or other fault condition.

Simply, the equipment which body is earthed or connected to the ground or earth through earth conductor is known as Class-I Equipment.

In this case if electrical connection go wrong and equipment body become electrified then connected earth wire drain down the current to ground and protect from dangerous electric shock if touch the equipment anyone.

The equipment like electric-heater, electric motor, electric iron etc. are under Class-I equipment.

Class-II Equipment

Sponsored:

The electrical equipment which does not include a means for connection to an Earth Conductor (EC), but provides supplementary insulation in addition to the basic insulation of the equipment is known as Class-II equipment. This equipment also known as double insulated equipment.  

The equipment like electric hair-drier, electric hair trimmer etc. are under Class-II equipment.

To get details specifications for Class-II Equipment you can check in British Standard BS2754.

Class-III Equipment

The electrical equipment in which protection against electric shock relies on supply at Separate Extra Low Voltage (SELV) system is the source of power that shall not exceed extra low voltage (50V ac or 150V dc) between conductors or to earth, also  the voltages higher than SELV are not generated in the equipment is known as Class-III Equipment.

To get more details about Class-III equipment you can check British Standard BS2754.

Bathroom wiring and water pool wiring is followed ELV and SELV system.

Considering over all insulation level the equipment are classified on five types as follows:

• Class 0
• Class I
• Class 0I
• Class II
• Class III

Where Class I, II & III already described, now we will explain the Class 0 and 0I:

 Class 0: The appliances those have no any protective-earth connection and used only a single level of insulation between live parts and exposed metallic parts for safety purposes. This Class 0 equipment is produced to use only for dry area, not for in wait weathered area. A single fault may cause a major electric shock or dangerous damages man or property without using the automatic operation of any fuse or circuit breaker. The country like UK  and New Zealand has prohibited to sale such insulation class equipment by their law. Only 110 V using countries are allow to use this class of equipment other wise most of 220 V using developing countries are using this Class 0 equipment,whether permitted officially or not.

Class 0I: Where the chassis of equipment is connected to earth with a separate terminal, not via the mains cable; that type of electrical equipment is described as Class 0I insulation equipment.The effect in this case provides the same automatic disconnection as Class I, for equipment that otherwise will be Class 0.

Sponsored: 

Hope the that made sense about 'The Equipment Classes Considering the Insulation Level to Protect Electrical Shock', if you have more information to share others. You may put below.

 References:

01. IEC 61140: Protection against electric shock — Common aspects for installation and equipment. International Electrotechnical Commission. 2001. (formerly: IEC 536-2: Classification of electrical and electronic equipment with regard to protection against electric shock, 1992);

02. BS 2754 : 1976 (1999): Memorandum. Construction of electrical equipment for protection against electric shock;

03. Wikipedia, https://en.wikipedia.org/wiki/Appliance_classes;

04. WAZIPOINT, wazipoint.blogspot.com

Current Ratings Correction Factors on Cable Laying Conditions

Fig- Crossectional View of XLPE Power Cable

Continuous Current Ratings Correction Factor Varies on Different Cable Laying Conditions

Today we will try to find how various laying conditions of cable become a factor for current ratings of XLPE insulated copper conductor power cables, means depends on cable laying various condition current carrying capacity increase or decrease. Such as various ambient air temperatures, various ground temperatures, various thermal resistivity of ground and various depth of cable laying is the factor for cable current ratings. 

In our previous post Continuous Current Ratings of XLPE Insulated Power Cable we try to find the current carrying capacity for various sheathed like Aluminium, Lead or Copper wire shield XLPE insulated copper cable.

To determine current capacity for the various laying conditions than those indicated on the every table, multiply table values by the correction factors shown below.

Correction Factors for Various Ambient Air Temperatures

Air Temperature(oC)	20 oC	25 oC	30 oC	35 oC	40 oC	45 oC	50 oC
Rating Factors	1.2	1.16	1.10	1.05	1.0	0.94	0.88

Air Temperature(oC)	15 oC	20 oC	25 oC	30 oC	35 oC	40 oC	45 oC
Rating Factors	1.08	1.04	1.00	0.96	0.91	0.87	0.83

Thermal Resistivity of Soil (oCm/w)	0.7	1.0	1.2	1.5	2.0	2.5	3.0
Rating Factors	1.14	1.00	0.93	0.84	0.74	0.67	0.61

Correction Factors for Various Ground Temperature Correction Factors for Various Thermal Resistivity of Ground
Correction Factors for Various Depth of Laying

Sponsored:

Depth of Laying (m)	Rating Factor
0.50 ~ 0.70	1.09
0.71 ~ 0.90	1.05
0.91 ~ 1.10	1.03
1.11 ~ 1.30	1.01
1.31 ~ 1.50	1.00