ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 2, Issue 2, February 2013
VOLTAGE AND FREQUENCY CONTROLLER
FOR SELF EXCITED INDUCTION GENERATOR IN
MICRO HYDRO POWER PLANT: REVIEW
Sonam Singh, A.N Tiwari

Abstract— This paper presents a review of the available
technology, as well as general background research on
standalone micro-hydro power plant or wind energy conversion
system. In this paper efforts has been done to present a control
structure which is dealing with both voltage and frequency
regulation of an isolated induction generator. It evaluates
different techniques of voltage and frequency regulations by
controlling methods for SEIG, which are found and scattered in
the literature. A review on their operational aspect and
comparative study is done.
Index Terms—Electronic load controller, Generalized
impedance controller, self-excited induction generator, voltage
source converter, energy storage.
I. INTRODUCTION
Power is extremely fundamental infrastructure on the whole
extension of many nations in the world. The requirement for
electrical energy is rising speedily in the world. It is being realized
that renewable energy sources can supplement the available energy
and provide a reasonable option in broad range of applications and
plays a significant role in resolving the doppelganger problem of
energy supply in the decentralized applications. Micro hydro power
plant is considered to be the promising source surrounded by
renewable energy. Renewable energy is a major constraint in the
economic development of the rural areas which includes solar
energy, biomass, wind, tidal, geothermal energy and flowing water
stream and these sources are effortlessly accessible in remote areas
which are island, ships, villages, military, hilly areas etc.
Commercial sources that are produced from the exhaustion of fossil
fuels like kerosene, diesel, petrol, coal and petroleum etc include
their own disadvantages such as air pollution and global warming.
Micro hydro is a type of hydroelectric power which produces up to
100 kW of electricity using the natural flow of water. Prime mover
of the hydraulic turbine rives the induction generator, and its
reactive power consumption is rewarded by the capacitor banks and
this whole system is known as self-excited induction generator
(SEIG)[1,2,3,4]. Induction generators is used now a days because of
advantages over synchronous generators i.e. brushless construction
with squirrel cage rotor, rugged, low cost, less maintenance,
operational simplicity, reduced size, no dc supply is needed ,against
faults self-protection, good dynamic reaction, and capability to
produce power at varying speed. [15,16].Induction generator offers
poor voltage regulation, frequency regulation under varying speed
and its value depends on the prime mover speed, capacitor bank
size.
Manuscript received Feb, 2013
Sonam Singh, Electrical Engineering Department
M M M Engineering College, Gorakhpur, U.P. (India)Contact
No.8004255721
Dr. A.N.Tiwari Associate Professor Electrical Engineering Department
M M M Engineering College,Gorakhpur, U.P. (India)
load and reactive power consumption. The generated voltage and
frequency from SEIG dependable upon the speed, capacitance, load
current, and power factor of the load [1,2]. Input mechanical power
remains constant with unregulated micro-hydro turbine, but due to
change in the load requirement of consumer load, output power is
not constant.
II.CAPACITOR EXCITED INDUCTION GENERATOR
SYSTEM
Magnetizing curve improves performance and efficiency. The main
pros of this operation of mode is that there is always margin of
increase or decrease of magnetizing flux and generated voltage and
improvement in overall efficiency. The capacitor bank provides
lagging reactive power for both load and asynchronous generator,
greater the value of capacitance greater will be the voltage [4,5,6,].
Excitation capacitance has to provide required voltage on consumer
load at the operating speed from a SEIG. The amount of capacitor
excitation at no load and rated load may be evaluated iteratively.
When induction generator (IG) is directly connected to the grid, it
starts generating power when its rotor is driven by a prime mover at
a speed higher than the synchronous speed which is determined by
the frequency of the grid voltage and its output voltage and
frequency is fixed at grid voltage and frequency. This is not the case
when the generator is stand alone. The voltage build up is instigated
either by the generator residual flux or by pre charging the excitation
capacitors. Hence it is difficult task to regulate the voltage and
frequency of self excited induction generators. Main reasons for the
poor voltage and frequency regulations are not only the

voltage drops at the stator

rotor resistances

leakage reactance

Influence of the frequency on the generator
magnetization characteristic.
SEIG performances rely on its magnetizing characteristics that are
achieved from the synchronous-speed test. A change in the load
impedance is directly proportional to the excitation of the machine
since the reactive power of the excitation capacitors is shared by
both the machine and the load. Thus the generating voltage drops,
when the impedance of the load is increased which results in poor
voltage regulation. Poor frequency regulation transpires when the
load is increased.
A. SEIG System Performance
The performance distinctiveness of the SEIG system depend mainly
on the following:
•Parameters of induction machine: The machine operating
voltage, rated power, power factor, rotor speed and operating
temperature and the induction machine parameters directly affect
the performance of the SEIG system.
• The Self-excitation process: The connection of a capacitor bank
across the induction machine stator terminals is necessary in the
case of standalone operation of the system and the use of fixed or
controlled self-excitation capacitors have a direct impact on the
performance of a SEIG system.
• Load parameters: The power factor, starting/maximum torque
and current, generated harmonics and load type also affect the
performance of the SEIG system directly.
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All Rights Reserved © 2013 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 2, Issue 2, February 2013
• Type of prime mover: performance of the SEIG system is
affected primary source i.e. hydro, wind biomass or combinations,
the
III. CLASSIFICATION OF VOLTAGE AND FREQUENCY
CONTROLLERS
In 1990s, a number of investigations and publications are available
on voltage and frequency controllers for an driven by uncontrolled
hydro turbine for single-phase as well as three phase power
applications. In analysis of this different voltage and frequency
controllers are testimony in the literature. The suitability to control
the terminal voltage and frequency regulation which is a key factor
deciding its use in various applications. Micro hydro power plant
various Controllers used for SEIG are as follows:
A. STATIC COMPENSATOR (STATCOM)
Static Compensator (STATCOM) is a piece of equipment that can
provide reactive maintain to a bus. It consists of voltage source
converters linked to an energy storage device on one side and to the
power system on the other. A STATCOM can be seen as a voltage
source behind a reactance. It provides reactive power generation as
well as absorption purely by means of electronic processing of
voltage and current waveforms in a Voltage Source Converter. This
means that shunt reactors and capacitor bank are not needed for
generation and absorption of reactive power, giving a compact
design, a small trace, as well as low noise and low magnetic impact.
The VSC has the same rated current when operating with capacitive
or inductive reactive current. Therefore a VSC having a convinced
MVA rating gives STATCOM twice the dynamic array in MVAr
which also found compact design. A DC capacitor bank is utilized to
support (stabilize) the controlled DC voltage needed for the
operation of the VSC. [7,8,9].
generator system. This feature increases the system efficiency and
capability. Based on this power system,[16,17,18,19,20] some
improvement are: 1) the STATCOM including a block to
compensate the current in the neutral wire of an induction generator
and voltage asymmetries on the dc bus of the converter and 2) the
battery bank is connected to a self-oscillating dc–dc converter based
in a relay feedback control. This choice provides certain advantages
over other options of bidirectional dc–dc converters, such as
simplicity of design, good performance over a wide operating range,
robustness, and lower cost. So the proposed bidirectional dc–dc
converter is an interesting option to consider in other renewable
energy systems, electric vehicles, or satellite applications. The
electronic converter consists of a four-leg voltage-source converter
(VSC), with a split-capacitor bus, and two dc–dc converters: a
chopper and a battery energy storage (BES) system [7,8,9,10]. The
three-phase four-wire VSC acts as an active filter, static Var
compensator, as well as a load balancing and ac voltage regulator.
The split-capacitor VSC contains a fourth leg to compensate the
neutral current (NCC) yielded by the unbalanced ac load system and
voltage asymmetries on dc bus capacitors of VSC is shown in fig2.
Fig. 2. Schematic diagram of the power system
.
Fig.1 Schematic diagram of SEIG with STATCOM.
SEIG with excitation capacitor, STATCOM, load and control scheme
are shown in fig 1.At no load excitation capacitors are selected to
generate the rated voltage of SEIG . The additional demand of reactive
power is fulfilled by STATCOM under varying loads. The STATCOM
acts as a source of lagging or leading current to maintain the constant
terminal voltage with variation in load. The STATCOM consists of a
three-phase IGBT based current controlled voltage source inverter.
Generated voltage of the SEIG system depends on the prime mover
speed, connected terminal capacitance, and load.[8,9] A prime mover
may be a micro hydel/wind turbine, biomass, or oil driven engine. The
speed of these prime movers may not be constant as it varies depending
on the energy source and the characteristics of the energy converter
employed. The controlled reactive power is responsible for keeping the
terminal voltage constant with change in load. A schematic diagram of
the SEIG with the STATCOM-based voltage regulator considered in
this paper is shown in Fig.1.
B. STATCOM WITH BATTERY ENERGY STORAGE
SYSTEM
A STATCOM is a self-oscillating bidirectional dc–dc converter for
interfacing battery energy storage in a stand-alone induction
The dc–dc converters regulate the frequency at the ac side of system.
One of them acts as an electronic load controller (ELC) by means a
chopper connected to a resistive load. The two insulated-gate
bipolar transistors (IGBTs) of the second dc-dc converter are
switched in a complementary form. Its duty cycle determines the
battery current (IBat) direction and magnitude. Since, V Bat < VDc the
bidirectional converter operates in buck or boost mode. It acts as a
buck converter in the charging phase of the BES unit and as a boost
converter in the discharging phase. Thus, this last converter allows
the battery to store/supply energy from/to the ac side of the system.
[8,9,10].The voltage pulses of the battery converter are filtered by a
third-order LCL filter. The proposed converter and its control loops
allow attenuating current harmonics, compensating reactive power,
and balancing the SEIG currents, while the energy storage system
can store or inject active power and, if necessary, the controlled dc
load dissipates the remaining generated power. So the SEIG
maintains the rated voltage and frequency under different loading
conditions, moreover, increasing the efficiency and availability of
the system.[8,9,10]
C. GENERALIZED IMPEDANCE CONTROLLER
The GIC is an operationally modified version of the static
synchronous compensator (STATCOM) that is capable of providing
bidirectional controlled flow of both active and reactive
power.[8,9,10] In order to keep the voltage and frequency within the
acceptable limits, and to improve the performance of the SEIG, the
control of active and reactive power within the generation system
becomes very important.GIC is a voltage source PWM bidirectional
inverter with a battery bank connected as its dc bus and
interconnecting reactor controlled at its ac bus. It offer variable
controlled impedance across the SEIG terminals according to the
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All Rights Reserved © 2013 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 2, Issue 2, February 2013
value of modulation index of inverter and phase angle between
fundamental component inverter output voltage and SEIG terminal
voltage. it absorbs as well as provide active and reactive energy
according to the load conditions thus frequency as well as voltage
SEIG is maintained constant [11, 12] The excess power delivered by
SEIG is stored in battery bank which is recovered when an overload
is connected to the system the modulation index and phase angle
between fundamental component of inverter output voltage and
SEIG terminal voltage are varied and flow active and reactive
power. The system regulates the output voltage and frequency but it
needs a complex control strategy to do that.[8,9,10]
The operation of a standalone self-excited induction
generator (SEIG) with generalized impedance controller (GIC)
(voltage source pulse width-modulated bidirectional inverter with
dc link battery) has been discussed. The generalized impedance
controller is found to be capable of maintaining the frequency of the
SEIG constant under open-loop condition, following the speed and
load perturbations.[10,11] The schematic diagram of a three-phase
SEIG, with a bank of fixed excitation capacitors, generalized
impedance controller and load are connected across its terminals,
which is shown in Fig. 3.
Fig.3.schematic diagram of a three-phase SEIG, with a bank of fixed
excitation capacitors, generalized impedance controller
The GIC is a voltage source pulse width-modulated (PWM)
bidirectional inverter with a bank of battery connected at its dc bus
and interconnecting reactor “Xs” connected at its ac bus. The “Xs”
is the leakage reactance of the coupling transformer. The GIC offers
variable-controlled impedance across the SEIG terminals according
to the value of modulation index “m” of the inverter and phase angle
“δ,” between the fundamental component of inverter output voltage
“VPWM” and SEIG terminal voltage “Vac.”The model of the
integrated generating system has been developed, which has the
following four salient components:
1) Induction machine; 2) Excitation system; 3) Load;
4) GIC -At this stage, it is worthwhile to have an insight into the
overall capability of a GIC. In the following section, the controller
active and reactive power (P and Q) handling capability is derived in
terms of its intrinsic parameters “m” and “δ.” Fig. 4shows per phase
equivalent circuit of the GIC connected to SEIG [11]. From Fig. 4,
the equations for P and Q drawn by the controller can be derived as
follows: where Vac is the terminal phase voltage of SEIG system;
VPWM the fundamental component of the ac output phase voltage
of the inverter; Iac the current through coupling inductance; Vdc the
dc bus voltage; δ the phase angle between the voltages; m the
modulation index of the PWM inverter; ric the ratio of amplitudes
between “VPWM” and “Vac”; Xs the coupling reactance; and k the
coupling transformer turns ratio.
Fig. 4 Per phase equivalent circuit of the GIC
p= V2ac ric𝐬𝐢𝐧(𝜹)
Q= V2ac
𝟏−𝒓𝒊𝒄 𝐜𝐨𝐬(𝜹)
𝑿𝒔
VPWM =Km Vdc= riac Vac
Fig. 5 Phasor diagram of GIC operation in different quadrant of
the power plane.
Fig. 5 shows the GIC operation in different quadrants of the P– Q
plane. The values of “ric” and “δ” determine the magnitude and
direction of active and reactive power flow in it. This is achieved by
suitably selecting “m” and “δ,” thus making the GIC to operate in
any quadrant of the P–Q diagram under both steady and transient
state. If the shaft input power to the SEIG is greater than the load
demand, excess power output by the SEIG is stored in the battery of
the GIC.Similarly, when the shaft input power to the SEIG is less
than the load demand, the GIC supplies the shortfall in the load
power demand. For a given ac bus voltage “Vac” and the reactance
“Xs” of the interconnecting reactor, maximum active and reactive
power that can be supplied or absorbed by the GIC and its dc bus
voltage “Vdc” are determined by the choice of critical modulation
index “mcrit.”[10,11,12]
A shunt connected VSI of small rating compared to that generator
with a battery bank on the DC side used to regulated voltage and
frequency of generated voltage .when there is excess power VSI can
store it into battery or supply active power to the load when the
power produced by induction generator is sufficient thus increasing
availability of system. A dump load is included in the system to
assist the VSI when there is a surplus of active power in the ac
system which cannot be absorbed by VSI and battery bank. The VSI
flow active power into the system when system frequency decreases
due to load increase .The VSI absorbed active power that is stored in
the battery bank when the system frequency is above the reference
value. The phase controlled dump load is activated when battery
bank is fully charged or when the power flowing through the VSI
exceeds its rated value.
The advantage of generalized impedance controllers is the
replacement of resistor used another schemes by a battery bank
increases efficiency of system. However more complex scheme is
required for the VSI to maintain battery voltage in a safe range
without compromising the voltage regulating capabilities of VSI.
D.ELECTRONIC LOAD CONTROLLER
The electronic load controller is an electronic device that maintains
a constant electrical load on the generator in spite of changing user
loads. This permits the use of turbine with no flow regulating and
their governor control system. The SEIG can be used to generate
constant voltage and frequency if the electrical load is maintained
constant at its terminals. The proposed ELC consists of an
uncontrolled rectifier and chopper with a series “dump” load. Proper
design of rectifier, chopper, and dump load is very important for
trouble free operation of ELC.[1,2,3,13] Uncontrolled hydro
turbines driving self-excited induction generators (SEIGs) are
preferred which maintain the input hydro power constant needing
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All Rights Reserved © 2013 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 2, Issue 2, February 2013
the generated output power to be held constant at varying consumer
loads. This requires a controllable dump load connected in parallel
with the consumer load such that the total generated power is held
constant. Various types of electronic load controllers (ELCs) for
self-excited induction generators (SEIGs) have been reported in the
literature [2,3,4,12].
Some of the well-known methods are binary
weighted-switched resistors, phase-controlled thyristor-based load
controllers, controlled rectifier feeding dump loads, an uncontrolled
rectifier with a chopper-controlled dump load, etc. In the binary
weighted three-phase switched resistors, the total resistive load is
divided in to a different number of elements wherein the system is
bulky, prone to failure, and less reliable. In a phase-controlled
thyristor-based load controller, the phase angle of
back-to-back-connected thyristors is delayed from 0 to 180 as the
consumer load is changed from zero to full load. Due to a delay in
firing angle, it demands reactive power loading and injects
harmonics in the system. It further requires complicated driver
circuits. In the controlled bridge rectifier type of ELC, a firing angle
is changed from 0 to 180 for single-phase and 0 to 120 for
three-phase to cover the full range of consumer load from 0 to
100%. In this scheme, six thyristors and their driving circuits are
required and, hence, it is also complicated, injects harmonics, and
demands reactive power. The fourth type ELC consists of an
uncontrolled rectifier with a chopper [a self-commutating device
such as an insulated-gate bipolar transistor (IGBT)] in series with a
dump load and it has the following advantages.
1) In this scheme, only one switching device and its driving circuit
are required. So the scheme is very simple, cheap, rugged, and
reliable.
2) It generates a low value of harmonics and does not demand
reactive power. Therefore, it is considered as the most suitable
scheme for this application.
3) Only one dump load is required and, hence, it is inexpensive and
compact.
In this paper, a detailed procedure of the analysis and design of
ELCs for SEIG is given for fixed-point operation. Based on this
design and analysis, prototypes of ELC are developed and tests are
performed on them with SEIG under steady-state and transient
conditions to verify the design methodology. The proposed ELC is
the combination of an uncontrolled rectifier, a filtering capacitor,
chopper, and a series dump load (resistor). The schematic diagrams
of ELC–SEIG systems are shown in Figs.6 for supplying
three-phase and single-phase loads with appropriately modified
ELCs. The uncontrolled rectifier converts the SEIG ac terminal
voltage to dc. The uncontrolled rectifier output has the ripples,
which should be filtered and, therefore, a filtering capacitor (C) is
used to smoothen the dc voltage. An IGBT is used as a chopper
switch. A suitable gate driver circuit has been developed that turns
on the chopper switch when the consumer load on SEIG is less than
the rated load and turns off the chopper switch when consumer load
on the SEIG is at a rated value. When the chopper switch is
switched on, the current flows through the dump load and consumes
the difference power (generated power consumed power) which
results in a constant load on the SEIG and, hence, constant voltage
and frequency at the load.
The ELC is fitted with three principal circuit protection features.
The protection features are meant mainly to protect user appliances
against conditions that might destroy certain types of appliances:
1. Over speed: Against too high a frequency. It can occur if the ELC
or dump loads fail and the turbine speeds up to run-away speed. The
emergency deflector system will also protect both the generator and
the user circuits in this case.
Fig.6. Schematic diagram of three-phase SEIG with an ELC feeding
three-phase consumer loads
2. Overvoltage: Against too high generator voltage. This is
dangerous for many types of appliances. Normally, this can only
happen with a compound type generator when the ELC or dump
loads fail. Because of this it is linked to the over speed protection.
An overvoltage situation might also occur if the generator AVR
fails.
3. under voltage: Against too low voltage. Then electrical motors
might be unable to start or might overheat.
Drawback ELC is when it’s used in this system voltage rating of
uncontrolled rectifier and chopper should be should be same for
SEIG. Another limitation is when it is introduce in system a lot of
harmonics which has to be filtered.
E. IMPROVED ELECTRONIC LOAD CONTROLLER
B.Singh, S. S. Murthy and Sushma Gupta [4] proposed an improved
electronic load controller is a combination of a three-phase insulated
gate bipolar transistor (IGBT) based current controlled voltage
source inverter (CC-VSI) which acts as a voltage regulator and a
high frequency DC chopper which keeps the rated power on the
SEIG and generated voltage and frequency constant in spite of
change of balanced/unbalanced loads. In Micro hydro plants,
governor unit of turbine can be eliminated using IELC, which is
simple and cost effective. The proposed IELC acts as reactive power
compensator, harmonic eliminator, load balancer and load
controller.[4,13]. In this case, load balancing, reactive power
compensation and harmonic elimination should be provided for the
load by the CC-VSI The control technique to regulate the terminal
voltage, load balancing, and harmonic elimination of the SEIG is
based on the controlling of source current.[12]
F. DECOUPLED VOLTAGE AND FREQUENCY (DVFC)
CONTROLLER
G.Kasal and B. Singh, [14],proposed controller is a combination
of a static compensator (STATCOM) and an electronic load
controller (ELC) for decoupled control of the reactive and active
powers of the induction generator system to control the voltage and
frequency respectively. In decoupled manner a new VF controller is
proposed which is having ability of controlling the voltage and
frequency. For controlling the voltage, a static compensator
(STATCOM) is used as a reactive power compensator along with
harmonic eliminator and a load balancer while for controlling the
frequency; an electronic load controller (ELC) is used to regulate the
total active power at the terminals of generator. The STATCOM is
realized using IGBTs (Insulated gate bipolar junction transistors)
based voltage source converter (VSC), and a capacitor as an energy
storage element at its DC link, while an ELC consists of a diode
bridge rectifier, a chopper switch and an auxiliary load resistance.
Fig. 7 shows the system configuration of CEAG (capacitor excited
asynchronous generator), DVFC (Decoupled voltage and frequency
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All Rights Reserved © 2013 IJARECE
ISSN: 2278 – 909X
International Journal of Advanced Research in Electronics and Communication Engineering (IJARECE)
Volume 2, Issue 2, February 2013
controller) (consisting 3 leg IGBT based VSC and diode bridge
rectifier based ELC) and the consumer loads. The delta connected
3-phase capacitor bank is used for the generator excitation and value
of an excitation capacitor is selected to generate the rated voltage at
no load. The CEAG generates constant power and when consumer
load power changes; the DC chopper of an ELC absorbs the
difference in power (generated-consumed) into an auxiliary load,
while STATCOM is used to regulate the voltage due to load
changes. Thus generated voltage and frequency are not affected and
remain constant during the changes in consumer loads. [14] The
DVFC is an arrangement of a STATCOM with an ELC. STATCOM
consists of IGBT based current controlled 3-leg VSC, DC bus
capacitor and AC inductors..
Fig 7.Schematic diagram of a proposed VF controller for an isolated
power generation
The output of the VSC is connected through the AC filtering
inductors to the CEAG terminals. The DC bus capacitor is used to
filter voltage ripples and provides self supporting DC bus. A DC
chopper in an ELC is used to control the extra power in the
controller auxiliary load due to change in consumer loads, so that
generated power at the generator remains constant. The controller
responds in a desired manner and regulates the system voltage and
frequency under direct on line starting of the asynchronous motor
and application/removal of load torque. In addition, the proposed
VF controller also functions as a harmonic eliminator, load balancer
for feeding linear/non-linear balanced/unbalanced loads.
III. COMPARISION VARIOUS TYPES OF VOLTAGE
AND FREQUENCY CONTROLLER
1. In induction generator electronic load controller is generally used
with chopper controlled dump load . It is very easy to execute this
type of converter because control scheme not complicated. This type
of converter also has disadvantage i.e. it creates lots of harmonics
into the system, thus system efficiency declines due to losses in
dump load.
2. Active and reactive power fluctuation across the SEIG can be
effectively controlled by the improved ELC contains VSC with an
auxiliary load and it also eliminates harmonics. Hence system
efficiency increases.
3. A STATCOM controller provides reactive power which loads
require so that output voltage stay constant. It removes harmonics
formed by dissimilar load conditions. STATCOM controller with
capacitor DC link would not be able to control active power output
of generator hence output frequency fluctuates in accordance to the
load variations.
4. Decoupled voltage and frequency controller consists of two
seperatearate systems into part ELC that controls active power by a
chopper controlled dump load and STATCOM that controls the
reactive power.
5. Voltage Source Inverter which consists of battery along its DC
link absorbs power. It stores battery in low load conditions and
discharge the battery. It gives back power to the system in full load
conditions hence can control active power output of generator thus
controls the frequency.
IV. CONCLUSIONS
A voltage frequency controller with a battery at its dc link can
control both active and reactive power. Under varying load
conditions, the voltage is kept constant by injecting/absorbing
reactive power and similarly, under varying active load, the
STATCOM maintains the voltage constant by injecting/absorbing
active power. A brief review of the existing topologies for the
voltage and frequency control is also presented. The proposed
controller has been established for parallel operated isolated
asynchronous generators in constant power application driven by
uncontrolled micro hydro turbines. It has been observed that the
controller is having capability of voltage and frequency regulation
along with harmonic compensation and load balancing. Besides, it
has resulted in a single point operation of the generators through
regulating the voltage, frequency, the load and capacitors to constant
value. Using the design criteria given here, the values of the ac
inductors, dc link voltage, dc link capacitor, and energy storage
parameters have been computed and their values have been selected
on the basis of considering their performance, safety, and
availability of the component rating. Development and research cell
needed for efficient performance of renewable systems .The control
system contains a voltage source inverter to stabilize the frequency
and a dump load to deal with voltage regulation
V. REFERENCES
[1] R. C. Bansal, “Three phase self- excited induction generators: An
overview ,”IEEE Trans. Energy Conv., vol. 20, no. 2, pp. 292–299,
Jun. 2005.
[2] B. Singh, S.S. Murthy, and Sushma Gupta, “Transient analysis
of self-excited induction generator with an electronic load controller
supplying static and dynamic loads”, IEEE Trans on Industrial
Applications, vol, 41, no. 5,p,.1194-1204, Sept 2005.
[3] B.Singh, S.S .Murthy, S.Gupta, “Analysis and implementation
of an electronic load controller for a self-excited induction
generator”in IEEE Proc - Generation Transmission and Distribution,
vol 151, no.1, pp. 51-60, Jan2004.
[4] B. Singh, S.S. Murthy, S. Gupta, “An improved electronic load
controller for a self-excited induction generator in micro hydel
applications” , in IEEE Industrial Electronics
Conference
(IECON), vol. 3, 2-6 Nov. 2003, pp2741 - 2746.
[5] J.M. Ramirez and Emmanuel. Torres M “An Electronic Load
Controller for the Self-Excited
Induction
Generator” IEEE
Transaction on Energy Conversion, vol. 22, no. 2, pp 546 – 548,
June 2007.
[6] Tamrakar, L. B. Shilpkar, B. G. Fernandes, and R. Nilsen
“Voltage and frequency control of parallel-operated synchronous
generator and induction generator with STATCOM in micro hydro
scheme” , in Proc IET –Gener. Transm. Distrib, vol.1, no. 5, pp
743-750, Sept 2007.
[7] J. A. Barrado, R. Griñó and H. Valderrama-Blavi
“Power -Quality Improvement of a Stand-Alone Induction
Generator Using a STATCOM With Battery Energy Storage
System ” IEEE Transactions On Power Delivery, Vol. 25, No.
4,October 2010.
[8] Raja Sekhara Reddy Chilippi, Bhim Singh and S.S.Murthy “A
3-Leg VSC Based Integrated Voltage and Frequency Controller for
a Self Excited Induction Generator Employing Water Pumping”
IEEE conference, Jul- Aug, 2010, India
[9]
Bhim
Singh,
S.S.Murthy,
and
Sushma
Gupta
“STATCOM-Based Voltage Regulator for Self-Excited Induction
Generator
FeedingNonlinearLoads”IEEE Transactions On Industrial Electron
ics, Vol. 53, No. 5, October 2006.
[10] Jayanta K. Chatterjee , B. Venkatesa Perumal, and Naveen
Reddy Gopu “Analysis of Operation of a Self Excited Induction
218
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Generator With Generalized Impedance controller ”IEEE
Transaction on energy conversion Vol. 22, No. 2, 2006 .
[11] B. Venkatesa Perumal and Jayanta K. Chatterjee,” Voltage and
Frequency Control of a Stand Alone Brushless Wind Electric
Generation Using Generalized Impedance Controller. 23, NO. 2,
June 2008.
[12] Bhim Singh, S. S. Murthy and Sushma Gupta “Analysis and
Design of Electronic Load Controller for Self-Excited Induction
Generators” IEEE Transactions on Energy Conversion, Vol. 21, No.
1, March 2006.
[13] Rajagopal, Bhim Singh “Improved Electronic Load Controller
For Off grid Induction Generator In Small Hydro Power Generation”
IEEE conferences 2011
[14] Gaurav Kumar Kasal and Bhim Singh “Decoupled Voltage and
Frequency Controller for Isolated Asynchronous Generators
FeedingThree-Phase Four-Wire Loads” IEEE Transactions on
Power Delivery, Vol. 23, No. 2, April 2008
[15] J.E. Barkle and R.W. Ferguson, “Induction generator theory
and application,” AIEE Trans.on Electrical Engineering, vol.73, pp.
12-19, 1954.
[16] Dan Levy, “Stand alone induction generators,” Electric Power
System Research, vol.41,pp.191-201, 1997.
[17] M. Godoy and F. A. Farret, Renewable Energy Systems.
Design and Analysis With Induction Generators. Boca Raton, FL:
CRC, 2004.
[18] B. Singh and G. K. Kasal, “Analysis and design of voltage and
frequency controllers for isolated asynchronous generators in
constant power applications,” in Proc. Int. Conf. Power Electronics,
Drives and Energy Systems, Dec. 12–15, 2006, pp. 1–7.
[19] J. A. Barrado, R. Griñó, and H. Valderrama, “Standalone
self-excited induction generator with a three-phase four-wire active
filter and energy storage system,” in Proc. IEEE Int. Symp.
Industrial Electronics, Jun. 4–7, 2007, pp. 600–605.
[20] L. Martínez-Salamero, H. Valderrama-Blavi, and R. Giral,
“Self-oscillating DC-DC switching converters with transformer
characteristics,”IEEE Trans. Aerosp. Electron. Syst., vol. 41, no. 2,
pp. 710–716, Apr.2005.
[21] D. R.Williams, C. Bingham, D. A. Stone, M. P. Foster, and A.
Gilbert,“Analysis of self-oscillating DC-DC resonant power
converters using a hysteretic relay,” in Proc. Eur. Conf. Power
Electronic and Applications, Sep. 2–5, 2007, pp. 1–9.
[22] Y. Hu, J. Tatler, and Z. Chen, “A bi-directional DC-DC power
electronic converter for an energy storage device in an autonomous
power system,” in Proc. Int. Power Electronics and Motion Control
Conf., Aug. 14–16, 2004, vol. 1, pp. 171–176.
Sonam Singh was born in Sultanpur , U.P., India. She completed B.Tech.
Degree in Electrcial and Electronics engineering from Sherwood College of
Engineering and Research Technology Barakanki ,Lucknow (U.P.), India in
2011. She is pursuing M.tech. (2nd Year) in Power Electronic and Drives
from the department of Electrical Engineering, M.M.M.Engineering College
Gorakhpur (U.P.) India. Her main research includes power electronic and
controllers.
\
Dr. A.N. Tiwari works an Associated Professor in the Electrical Engineering
Department of MMM.Engineering College, Gorakhpur. .He is member of
ISTE,MIE(INDIA), and IETE.He supervised 16 M.Tech dissertations. His
field of specialization in Electrcial Power Apparatus and Drives
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