Important Points About Energy Conservation in Electrical Installation System

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Important Points About Energy Conservation in Electrical Installation System

Energy Conservation in Electrical Installation System

  • The cascade efficiency in T and D system from output of power plant to end use is nearly 87%. 
  • The losses taking place in the transmission and distribution system are classified as : (A) Technical losses. (B) Commercial losses.
  • Technical losses are developed due to energy dissipated in conductors used for transmission and distribution.
  • Loses which do not take place in lines, come under the category of commercial losses the losses due to theft of energy faulty energy meters, etc. come under commercial losses.

Following are reasons for high technical losses :

  1. Insufficient investment on transmission and distribution network.
  2. Random growth of sub-transmission and distribution network.
  3. Large scale electrification of rural and urban area.
  4. Too many stages of transformation.
  5. Improper load management.
  6. Poor reactive load compensation.
  7. Poor quality of equipment used.

Following are main reasons of high commercial losses :

  1. Extension of agricultural loads without proper sanctions.
  2. Wrong reading of meters, purposefully.
  3. Wrong connection of meters.
  4. Stopping working of meters.
  5. Purposeful burning of energy meter.
  6. Reverse rotation of meter.
  7. Improper testing and calibration of energy meter or changing CT ratio to reduce reading.

Following steps can be taken to reduce technical losses :

  1. Improve the weakest area for maximum benefit of distribution line.
  2. Shifting of distribution transformer to load centre.
  3. Installing additional transformer if present one is over loaded.
  4. Use small capacity to supply concentrated loads.
  5. Use energy efficient transformers. 
  6. Use shunt capacitors at sub-stations. 

Following steps can be taken to reduce commercial losses :

  1. Set up a special vigilance squad to prevent theft.
  2. Those who tamper the meter, should be property punished.
  3.  Energy audit should be introduced.
  4. Proper installation of energy meters.
  5. Use electronic energy meters.
  6. Meter should be timely checked.
  7. Faulty meters should be replaced with proper meters. 

Following energy conservation techniques are used in transmission and distribution system :

  1. Reducing I2R losses. 
  2. Compensating reactive power flow by the following means : (a) Using shunt capacitors. (b)Using synchronous compensator.(c) Using series capacitors.
  3. Voltage control methods by the following methods : (a) Transformer tap-changing (b) Booster transformer (c) Static VAR system.
  4. Optimising distribution voltage.
  5. By balancing phase currents of distribution system.
  6. By using energy efficient transformer.
  • Energy conservation equipment is that equipment which when used in the system will conserve energy. 
  • Following energy conservation equipments related to lighting system are used : 

(a) Centralized control equipment 

(b) Occupancy sensors 
(c) Control gears, such as (i) Dimmers, (ii) Regulators, (iii) Stabilizers 
(d) Energy efficient lighting controls such as time based control, such as dial timer, electronic switches, day light linked control and localized switching.

  • Following energy conservation equipments related to electrical motors are used. (a) Soft starter. (b) Static capacitors. (c) Automatic star-delta starter. (d) Variable speed drives.
  • Following energy conservation equipments are used in transmission and distribution system.

(a) Maximum demand controller. (b) Automatic power factor controller. (c) KiloVAr controller (d) Intelligent p.f. controller.

Soft starter provides a reliable and economic solution to the problem of high inrush current during starting by delivering a controlled release of power to the motor with the following advantages : 

  1.  Less mechanical stress.
  2. Improved power factor. 
  3. Lower maximum demand.
  4. Less mechanical maintenance.

Advantages of power factor improvement

  1.  kVA loading reduces.
  2.  I2R losses are reduced.
  3.  Voltage level at load is increased.
  4.  Reactive component is reduced.
  • Capacitor should be located dose to load.
  • Considerable savings can be realized by controlling power use by providing maximum demand controller.
  • Automatic power factor control relay controls the power factor of the installation by giving signals to switch on or off power factor correction capacitors.
  • Intelligent power factor controller determines the rating of capacitance connected in each step during the first hour of its operation and stores them in memory, based on this measurement IPFC switches on the most appropriate steps thus eliminating the hunting problems normally associated with capacitor switching.
  • Lamp : It is an equipment which produces light.
  • Incandescent lamp : It produces light by means of a filament heated to incandescence by flow of electric.
  • Reflector tamp : It is incandescence lamp provided with high quality internal mirror.
  • Gas discharged lamp : It produces light by excitation of gas contained in either tubular or elliptical outer bulb.
  • Luminair : It is a device that distribute filters or transforms the light-emitted from one or more lamps.
  • Ballast : A current limiting device.
  • Ignitors : They are used for starting high intensity metal halide or sodium vapour lamps.
  • Illuminance : It is the quotient of the luminous flux incident on an element of the surface at a point of surface containing the point by the area of that element. 
  • Lux : Illuminance produced by a luminous flux of one lumen, uniformly distributed over a surface area of one quare metre. 
  • Luminous efficiency : It is the ratio of luminous flux emitted by a lamp to the power consumed by the lamp.
  • Colour rendering index : It is a measure of the degree to which the colours of surfaces illuminated by a given light confirm to those of the same surfaces under a reference illuminent. 

Some good practices in lighting :

  1. Installation of energy efficient fluorescent lamps.
  2. Installation of CFL lamps.
  3. Installation of metal halide lamps in place of mercury/sodium vapour lamps.
  4. Installation of sodium vapour lamps where colour rendering is not critical.
  5. Installation of LED panel indicator lamps instead of filament lamps.

Light control :

  1. By switching off when not required. 
  2. Grouping of lighting system.
  3. Installation of microprocessor based controller.
  4. Optimum usage of day light.
  5. Installation of exclusive transformer for lighting.
  6. Installation of servo stabilizer for lighting feeder.
  7. Installation of high frequency electronic ballasts in place of conventional ballasts.

Laws of illumination :

  1. Inverse square law : Illumination due to a point source at a point is proportional to m
  2. Lambert’s cosine law : When the light falling on the plane makes an angle with the perpendicular to plane from the source, then illumination on the plane is proportional to cosine of angle.

Factors on which quality of lighting system depends :

  1. Distribution of light. 
  2. Degree of diffusion.
  3. Glare.
  4. Colour of light 
  5. Steadiness of light.
  6. Uniform distribution of light.

Following factors affect on illumination scheme design and they are defined as :

  1. Space height ratio =Horizontal distance between lamps /  Mounting height from working plane.
  2. Utilization factor (Absorption factor) = Total lumens uitilized on working plane / Total lumens given out by lamps  
  3. Depreciation factor or maintenance factor =  Illumination under normal working condition / Ilumination when everything is clean.
  4. Waste light factor = When a surface is illuminated by number of lamps, there certain amount of wastage of light flux due to overlapping etc. Its value for rectangular area is nearly 1.2 and for irregular shaped area is nearly 1.5.

Existing lighting system in a industry can be assessed by the following methods : (a) Photoemissive cells. (b) Semi – conductor photo-electric transducers. (c) Thermal sensors 
Different methods to improve energy conservation system be used.
Following energy efficient lighting controls systems must be used :

  1. Occupancy sensors.
  2. Time based controls.
  3. Day-light linked control.
  4. Localized switching

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