Reactive Power Compensation Using Capacitor

• Power Factor correction PFC is applied to electric circuits as a means of minimizing the inductive component of the current and thereby reducing the losses in the supply... • Power fa

Literature Survey

Problem Identification

Objective Of The Project

Project Analysis And Design

• Power Factor correction (PFC) is applied to

electric circuits as a means of minimizing the inductive component of the current and thereby reducing the losses in the supply

• Power factor (PF) is the name given to the ratio

of the active or usable power measured in

kilowatts (KW), to the total power (active and

reactive) measured in kilovolt amperes (KVA).ie: Power Factor = KW / KVA.

POWER TRIANGLE

Electrical power in an AC circuit has three components: real

power (P), reactive power (Q) and apparent power (S)

Real power is considered to be the work producing power

measured in watts (W), or kilowatts (kW) Real power produces the mechanical output of a motor

Reactive power is not used to do work but is needed to operate equipment and is measured in volt amperes reactive (VAR) or ‐ ‐kilovar (kVAR)

Apparent power (also known as demand power) is comprised of (vectorial sum) both real and reactive power and is measured in units of volt amps (VA) or kilovolt amps (kVA) ‐ ‐

DISADVANTAGES

OF LOW POWER FACTOR

Increases heating losses in the

transformers and distribution equipment Reduce plant life.

Upgrade costly equipment.

Decrease energy efficiency.

Increase electricity costs by paying

penalties.

Power factor correction capacitors; Essentials & Cautions-

M.H.Shwehdi, M.R.Sultan

Dept of Electr Eng., King Fahd Univ of Pet & Miner., Dhahran

Date of Current Version : 06 August 2002

Page(s): 1317 - 1322 vol 3

Optimal selection of capacitors-IEEE:

S.Sudehararajan & A Pahwa

Dept of Electr & Comput Eng., Kansas State Univ., Manhattan, KS Date of Current Version : 06 August 2002

Page(s): 1499 - 1507

Optimal Reactive Power Planning and Compensation Effects

on Transmission Loss Components

K Barot; H Bhattacharya,

Power & Energy Syst Group, Univ of Waterloo.

Date of Current Version : 23 July 2007

Page(s): 1 - 7

Universal input single-phase single-stage power supply with power factor correction and automatic voltage clamping

Chongming Qiao; Smedley, K.M

Dept of Electr & Comput Eng., California Univ., Irvine, CA

Date of Current Version : 07 August 2002

Page(s): 907 - 913 vol.2

High-capacity hybrid power filter for harmonic suppression and reactive compensation in the power substation

Lina Wang An Luo

Dept of Electr Eng., Tsinghua Univ., Beijing

Date of Current Version : 10 January 2005

Page(s): 215 - 220 Vol.1

LPF is a main problem that our industries face in today’s world There are many factors that leads to LPF.

The aim of our project is reactive power compensation using automatic capacitor banks.

We using automatic capacitor PFC, because fixed

capacitor has following disadvantages……

• Manual operation(on/off)

• Not meet the require kVAr under varying loads.

• Can result leading power factor

• Cause over voltage

• Penalty by electricity authority

Types of PFC

The choice of the correct power factor correction

equipment depends on the type of loads present and

by their way of working

• Individual compensation is most effective if the majority of the reactive power is concentrated on few loads with high power and that work for long period of time

• Central compensation is best suited for systems where the

load fluctuates through out the day If the absorption of reactive power is variable, it is advisable the use of automatic regulation than fixed capacitors

INDIVIDUAL COMPENSATION

CENTRAL COMPENSATION

PROJECT ANALYSIS &

DESIGN

after the installation of the capacitor bank that increased the PF to 0.94

The cost of capacitor was found to be Rs.200/kVAR and the cost of

capacitor installation could be replaced in a period of 1 year and 2

months

SITES MOTORS RATING WORKING PERIOD(hrs) TRUE POWER(kW) TOTAL kWh

PUMP HOUSE 1 MOTOR 1 52 HP 3

MOTOR 2 52 HP 3 76.5 229.5 PUMP HOUSE 2 MOTOR 1 37 Kw 3

MOTOR 2 37 Kw 3 74 222 RAIN WATER

PURIFING PUMP 5 HP 3 3.8 11.4

AD BLOCK INDUCTION MOTOR 60 HP 6

INDUCTION

MOTOR

3.7

Kw 6 47.83 287 FIRE HOUSE PUMP 60 HP 10 44.13 441.3

TELEPHONE

EXCHANGE MOTOR 20 HP 24 14.71 353 BELT DRIVE MOTOR 1 7.5 HP

MOTOR 2 7.5 HP 6 11 66.2 SUPPLY MOTOR 5 HP 6 3.68 22.1

NORTH END MOTOR 12 Kw 12 12 144

HOSPITAL MOTOR 1 12 Kw 24

MOTOR 2 12 Kw 24 MOTOR 3 12 Kw 24 36 864 CISF MOTOR 1 12 Kw 24

MOTOR 2 12 Kw 24 24 576

• Total load demand =405.65kW

1% energy charges for every 0.01 fall in pf from 0.9

Cost of energy per unit=2.75Rs/kWh/month

Selection of capacitor for 0.85 pf

PF old = 0.85

PF new = 0.94

M =0.367

kVAR cap =165.81kVAR

Cost of capacitor= Rs 200 per kVAR

Total cost of capacitor, kVARcap

Here our hardware is of passive…….

No power consumption.

Inexpensive (unless large coils are required)

POWER FACTOR CORRECTION: Advantages

• Reduced demand charges

• Reduction in size of transformers, cables and switchgear in new installations

• Less total plant KVA for the same KW working power

• Automatically switch on/off relevant capacitors steps for

consistent power factor

• Continuously sense and monitors the load

FUTURE SCOPE

In our project, we have not considered harmonics In future, we can improve the power factor by adding a reactor circuit with the

capacitor bank to eliminate harmonics As a result, especially the 3 rd

harmonic component can be detected and suppressed and power factor in whole can be raised up to a value of 0.99.

REFERENCES