REACTIVE POWER COMPENSATION TO GENERATE NEW ENERGY SOURCE 1

Abstract

In AC circuits, energy is stored temporarily in inductive and capacitive elements, which results in the periodic reversal of the direction of flow of energy between the source and the load. The average power after the completion of one hole cycle of the AC waveform is the real power, and this is the usable energy of the system and is used to do work, whereas the portion of power flow which is temporarily stored in the form of magnetic or electric fields and flows back and forth in the transmission line due to inductive and capacitive network elements is known as reactive power. This is the unused power which the system has to incur in order to transmit power. Inductors (reactors) are said to store or absorb reactive power, because they store energy in the form of a magnetic field. Therefore, when a voltage is initially applied across a coil, a Magnetic field builds up, and the current reaches the full value after a certain period of time. This in turn causes the current to lag the voltage in phase. Capacitors are said to generate reactive power, because they store energy in the form of an electric field. Therefore when current passes through the capacitor, a charge is built up to produce the full voltage difference over a certain period of time. Thus in an AC network the voltage across the capacitor is always charging. Since, the capacitor tends to oppose this change; it causes the voltage to lag behind current in phase. There are more researchers are going to disused about to reduce the reactive power and how to get good quality of power. In this paper focused one kind of reactive power compensation by generating new energy source from the fly ash waste heat in a boiler used plants.

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58 | Abi International Journal Of Modern Science & Engineering
Division – Electrical Engineering
ABI International Journal of Modern Science & Engineering
(1)1 January-June 2012. pp. 58-66
REACTIVE POWER COMPENSATION TO GENERATE NEW
ENERGY SOURCE
1M. VIVEK 2G. RAJKUMAR 3K. SWAMINATHAN
1M.Tech Power System, Dr.M.G.R.University,Maduravoyal Chennai,India
2M.Tech Power System, Dr.M.G.R.University,Maduravoyal Chennai,India
3M.Tech Power System, Dr.M.G.R.University,Maduravoyal Chennai,India
Email:MARUVIM@gmail.com
Abstract:
In AC circuits, energy is stored temporarily in inductive and capacitive elements, which results in the
periodic reversal of the direction of flow of energy between the source and the load. The average power
after the completion of one hole cycle of the AC waveform is the real power, and this is the usable energy
of the system and is used to do work, whereas the portion of power flow which is temporarily stored in
the form of magnetic or electric fields and flows back and forth in the transmission line due to inductive
and capacitive network elements is known as reactive power. This is the unused power which the system
has to incur in order to transmit power. Inductors (reactors) are said to store or absorb reactive power,
because they store energy in the form of a magnetic field. Therefore, when a voltage is initially applied
across a coil, a Magnetic field builds up, and the current reaches the full value after a certain period of
time. This in turn causes the current to lag the voltage in phase. Capacitors are said to generate reactive
power, because they store energy in the form of an electric field. Therefore when current passes through
the capacitor, a charge is built up to produce the full voltage difference over a certain period of time.
Thus in an AC network the voltage across the capacitor is always charging. Since, the capacitor tends to
oppose this change; it causes the voltage to lag behind current in phase. There are more researchers are
going to disused about to reduce the reactive power and how to get good quality of power. In this paper
focused one kind of reactive power compensation by generating new energy source from the fly ash waste
heat in a boiler used plants.
Key words: SS layout, demand curve, Energy generation, Design.
Introduction
Need for Reactive power compensation.
The main reason for reactive power compensation in a system is: 1) the voltage regulation; 2) increased system
stability; 3) better utilization of machines connected to the system; 4) To reduce the losses associated
with the system; and 5) to prevent voltage collapse as well as voltage sag. The impedance of transmission lines
and the need for lagging VAR by most of the machines in a generating system results in the consumption of
reactive power, thus affecting the stability limits of the system as well as transmission lines. Unnecessary
voltage drops lead to increased losses which needs to be supplied by the source and in turn leading to outages in

59 | Reactive Power Compensation To Generate New Energy Source
Division – Electrical Engineering
the line due to increased stress on the system to carry this imaginary power. Thus we can infer that the
compensation of reactive power not only mitigates all these effects but also helps in better transient response to
faults and disturbance. In recent times there has been an increased focus on the techniques used for the
compensation and with better devices included in the technology, the compensation is made more effective. It is
very much required that the lines be relieved of the obligation to carry the reactive power, which is better
provided near the generators or the loads.
Available Methods
Shunt capacitor
Shunt capacitors can be connected in to shunt of the line. It used to supply reactive power and to boost the local
voltages. They are used throughout the system and are applied in a wide range of sizes.
Limitations
The reactive output is proportional to the square of the voltage. Consequently the reactive poor output is
reduced at low voltages when it is likely to be needed most.
Series capacitors
Series capacitors are connected in series with the line conductors to compensate for the inductive reactance of
the line. This reduces the transfer reactance between the buses to which the line is connected increases
maximum power that can be transmitted and reduces the effective reactive power flow.
STATCOM
It is a regulating device which can be used to regulate the flow of reactive power in the system independent of
other system parameters. STATCOM has no long term energy support on the dc side and it cannot exchange real
power with the ac system. In the transmission systems, STATCOMs primarily handle only fundamental reactive
power exchange and provide voltage support to buses by modulating bus voltages during dynamic disturbances
in order to provide better transient characteristics, improve the transient stability margins and to damp out the
system oscillations due to these disturbances.
Limitations
The only problem about the STATCOM is t can able to compensate up to certain level of voltage DIP and Swell
after the critical limit it can able to supply for a particular period only
UPFC
Unified power flow controller, It used to inject the reactive power and absorbed the reactive power depending
up on the needful of the line/network.
Limitations
Due to the common storage between the shunt and the series converters, if the storage gets affected the system
will get collapsed.
At normal condition

60 | Abi International Journal Of Modern Science & Engineering
Division – Electrical Engineering
Figure 1 Load Flow Analysis
From the figure 1 shows under normal operating condition the load voltage will be act at very low from the
sending end to receiving end. The end users are affecting from the power quality problem and the low voltage
problem.
Energy generation
Energy is one of the most important in our life without energy we can’t does anything in this world. Now days
there are most of the energy sources can be consumed by us in various applications. At the same time the
growth of the fossil fuel are also become reduced. In INDIA still we cannot meet the energy demand so that to
meet it we can go for atomic energy source. It is one of the harmful for human being and other lively hood. So
now we are all pushed to generate the electrical energy sources and to minimize the consumption. In this part
deals energy generation from the fly ash waste heat. Normally boiler used plants fly ash are stored in an ash
shoot. After that it can be cooled by water and disposed in this heat energy are sufficient to take the electrical
energy source
Energy demand in INDIA
From figure 4 shows the Yearwise increased consumers in lakhs. From this analysis In India the consumers
ratio will be increased at 20 percent at the normal level.
Figure 2 Consumer ratio

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Division – Electrical Engineering
NAVELPATTU ANNANAGERFEEDER (THRIUCHIRAPPALLI FEEDER)
Figure – 3 TNEB Layouts
Figure 4 Demand ratio
From figure 4 shows the deficity of energy, is analysied during the peack hour (18 hours to 22 hours). From this
the average demand was 1500MW to 3400MW. So that we are all focusing the new energy source and the same
time to compensate the reactive power.
Extinction
In previous methods the energy has been taken solar panel to implement at the bottom of the ash room. In this
part proposed to implement the solar panel in the side wall of the ash shoot with its combination connected with
the bottom panels.

62 | Abi International Journal Of Modern Science & Engineering
Division – Electrical Engineering
Design
Figure – 5
Proposed design
Figure - 6
During our field test, the bottom of ash choot maintained 120 degree cell maximum over a period of 8 hours.
By making use of this virtue, the photo voltaic cells enough to actuate required volume of power compensation
units. Let us consider we generate 15 KW power form it.
Design for photovoltaic modules and batteries:
The average power that should be supplied by the batteries band during the system operation is defined by
Pbat = Pout / efficiency
Where Pbat is average power supplied by the batteries band system efficiency (80%) and pout is power drained
by the load. The consumption of the system in amperes hour per day is

63 | Reactive Power Compensation To Generate New Energy Source
Division – Electrical Engineering
Ah1 = Pbat flux / Vdc
Where Ah1 is Daily consumption of the load in Ah/day tflux is time of operation of the load a day and Vdc is
voltage of the battery link. The average capacity of electrical energy production in amperes hour per day of
each photovoltaic panel of 12 v is given by Ahd = IRs Rmed/ Rs
Where Ahd is energy supplied by the photovoltaic module per day IRS is current supplied by the module for
radiation Rs. Rmed is daily radiation average rate at the installation place and Rs is the solar radiation for INDIA.
Let us consider the current supplied by the module for radiation Rs is 45 A. daily radiation average rate at the
installation place is 5000 wm2/day
The minimum number of photovoltaic panels necessary for specified energy consumption is given by NP= Ah1
d Vdc /Ahd 12
Where Ah1 is daily consumption of the load the total capacity of the batteries necessary for operation system is
given by
CBat = Ah1 d Vdc/ DC VBat
Where CBat is total capacity of the batteries d is autonomy days Vdc is voltage of the batteries link, DC is
discharge depth VBat Voltage of the battery.
Boost Converter
The PV cell generates 12V or 24 V this generated voltage is boost up by DC -DC boost converter. The main
factor for designing DC converters for solar energy system is the gain, output power and ease of design.
DC- DC Boost Converter Design
Figure - 7
Choose a sampling frequency of 20 kHz and a duty cycle of 0.80
vo = Vin/(1-D)2 .
The input to the DC- DC Boost converter is the output of the battery. The output of the battery is 24 V,so
consider Vo = 600 v. Then the load will equal R=V02 /P.
The system is designed for supplying the load of 15 kw. Therefore per phase power will be kw so R= 72 ohm
hence

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Division – Electrical Engineering
I0 =V0/R =8.33 A.
The current of the first inductor equals
IL1 =I0/ (1-D) = 208.25 A and the current of the second inductor is
IL2 =I0/ (1-D) =41.65 A.
In order to ensure that the converter is working in the continuous conduction mode, the current variations and ξ
through the inductors has to be much lower than unity where
ξ1= (∆ IL1/2)/ IL1=D (1-D) 4 /2 .R/FL1
ξ2 = (∆ IL2/2)/ IL2=D (1-D) 2 /2 .R/FL2
The current variations ξ1 =ξ2=0.05 so that
L1 = 0.046 Mh and L2 = 1.152 Mh choose a maximum load of 5 kw, a step up gain of G=16, a switching
frequency of 20 kHz. Capacitors of values c1= 100µf and c2 = 200 µf are taken Voltage and current rating of
diode D1 and D2 is 100 v and 300 A respectively voltage and current rating of diode D3 is 800 V and 100 A.
DC AC Inverter Design
Figure - 8
The output of the DC -DC Boost converting is goes to the input of the DC AC inverter. Vdc = 600 V
Current supplied by the DC AC inverter can be calculated by
Power = 3
After substituting the value of P and V the current supplied by the inverter is I=7.2A. If current ripple (icr(p-p))
through the AC inductor is allowed to be 50 % the inductance can be calculated as
LF=( ) ma Vdc/6 afs ic(p-p)
Where fs is the switching frequency which is taken as 10 kHz. During transient, current rating is likely to vary
from 120 % to 180% of the steady state value. In inductance calculation current rating of 120 % of the steady
state current is taken during transient. The voltage drop across

65 | Reactive Power Compensation To Generate New Energy Source
Division – Electrical Engineering
AC inductor= 2: flf Is = 16.05 Under dynamic condition change in terminal voltage of the load is considered
to be 10 % maximum
AC Voltage =
Where Vd is voltage drop across inductor, Vd is 10 of Vph for dynamic conditions. After substituting the value
of V1 the voltage across inductor is = 2Pi fl fIs
And 10 % of V and maximum voltage is = 676 V the peak value of current is Is. = 10.20 A considering the
safety factor of 1.25, the
Maximum line current = 1.25 (Icr(p-p) +Is(peak))
by substituting the value of peak to peak ripple, the peak current instantaneous line current is 5 A from the
above calculation the maximum voltage across the device may be 67 V and the current through the device may
be 10.20 A commercially available rating is 800 V and 20 A higher than 676 V and 10.20 A. respectively.
Designed Rating DC AC Inverter
Quantity
Rating
Current Rating
7.20 A
DC bus voltage
600 V
AC inductor
7.10mH
Voltage rating of IGBT
Switch
800 V
Current Rating of IGBT
Switch
20 A
Load flow analysis with compensators
Figure - 9
By adding generated new energy source the end user received quality of power. And the same time our energy
sector will get a new energy source. From this energy can be used to give quality of power from some specified
load means the loss of power during transmission and the compensation equipment will be reduce.

66 | Abi International Journal Of Modern Science & Engineering
Division – Electrical Engineering
Conclusion
In the existing systems the external supply or the supply from the same system is utilized in order to compensate
the variations in the voltage levels but in case of proposed system the energy is supplied from the wastage
generated from the thermal is used so this type of conservation is also a form of Green energy utilization.
Reference
1. M.VIVEK,G.RAJKUMAR’Green Energy’International Research Journal of Engineering and
Technology Jan –Mar 2011
2. .Fang Liu, Ryuichi Yokoyama, Yicheng Zhou, Yong Li, Min Wu,‘Reactive Power Compensation
Characteristics of a New SVC for Industry Custom Power System’ International Conference on Power
Systems Transients (IPST2009) in Kyoto, Japan June 3-6, 2009
3. Paolo TENTI,Paolo Mattavelli and Elisabetta TEDESCHI,University of Padova, Italy,’
Compensation techniques based on Reactive Power conservation’,Electrical Power Quality and
Utilization Journal 2007.
4. P.K.Nag ‘Power Plant Engineering Steam and Nuclear’, 1999 edition, Tata McGraw Hill Publication.
5. G.D.Rai ’Solar Energy Utilization’, fifthe edition, Kannan publication.
6. G.D.Rai ‘Non Conventional Energy Sources’,reprint 2001,Kannan publication