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1. IEEE7th
RV College of
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EL PRESENTATION
SUBMITTED BY:
LANKESH HD (1RV22EPE06)
MANOJ C (1RV22EPE07)
R RAKSHITH (1RV22EPE11)
UNDER THE GUIDENCE OF:
DR. PANDRY NARENDRA RAO
Assistant Professor
Dept. Of EEE, RVCE.
RV College of Engineering
Department of Electrical & Electronic Engineering
“TRANSIENT ANALYSIS OF SELF-EXCITED INDUCTION
GENERATOR WITH ELECTRONIC LOAD CONTROLLER (ELC)
SUPPLYING STATIC AND DYNAMIC LOADS”

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TABLE OF CONTENTS
• ABSTRACT
• INTRODUCTION
• WORKING
• WAVEFORMS
• RESULTS
• CONCLUSION
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ABSTRACT
• This paper deals with the unexplored and relevant topic of transient behavior of an uncontrolled
micro-hydro-turbine-driven SEIG-ELC system feeding both dynamic and static loads.
• Subsystems comprising the prime mover, ELC, and load are modeled, synthesized, and analyzed.
• In view of the need to feed both dynamic [three-phase induction motor (IM)] and static loads from
such systems, the transient behavior due to switching in of such loads is of interest and is carried
out here.
• A composite mathematical model of the total system has been developed by combining the
modeling of prime mover, SEIG, ELC, and load
• For the starting of an IM, a star/delta starter is used to avoid inrush current.
• Harmonic analysis is carried out to find total harmonic distortion of the terminal voltage and current
to assess its power quality.
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INTRODUCTION
• Fast depletion of fossil fuels has drawn attention towards the use of nonconventional energy sources
like wind, biomass, tidal/wave, and small hydro potential.
• In remote locations, harnessing of electrical energy from such local resources can be cheaper and
easier compared to grid connection, which involves long transmission lines and associated losses.
• The system must be economical, rugged, and user friendly since local communities are often not
techno-savvy.
• Uncontrolled low head turbines are prescribed for such applications, which maintain almost
constant input power due to fixed head and discharge.
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INTRODUCTION
• The self-excited induction generator (SEIG) has distinct advantages over a conventional
synchronous generator for such systems.
• Constancy of power requires a system to maintain generator output power constant at varying
consumer loads. Normally, a device named an electronic load controller (ELC) is used for this
purpose.
• A simple viable system consists of an uncontrolled rectifier–chopper system feeding a “dump”
resistive load, with the power in the dump load controlled through variable duty cycle of the
chopper to keep the sum of consumer load and ELC dump power constant.
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WORKING
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Figure 1: Schematic diagram of three-phase SEIG with ELC

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WORKING
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•It consists of a three-phase delta-connected SEIG driven by a constant power prime mover (typically, an
uncontrolled micro-hydro turbine).
•The excitation capacitors are connected at the terminals of the SEIG, which have a fixed value to result
in rated terminal voltage at full load.
•Since the input power is nearly constant, output power of the SEIG must be held constant at all loads.
•Any decrease in load may accelerate the machine and raise the voltage and frequency levels to
prohibitively high values to affect other connected loads.
•The power in surplus of the consumer load is dumped in a resistance ( ) through an ELC connected
at the terminals of the SEIG.
•The ELC consists of an uncontrolled rectifier in series with a chopper and dump load (resistors).
•The duty cycle of the chopper is adjusted so that the output power of the generator remains constant.
•The duty cycle of the chopper is decided through closed- loop control of the SEIG output voltage

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WORKING
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Figure 2: Control circuit of chopper-based electronic load controller

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WORKING
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•The SEIG voltage is sensed through the sensor and rectified through the single-phase rectifier for
feedback signal (Vdf ) .
•The rectified feedback signal is compared with reference voltage signal ( Vref) and the error signal is fed
to the proportional–integral (PI) controller.
•The output of the PI controller is compared with the saw tooth carrier waveform in a pulse width-
modulation (PWM) controller to control the duty cycle of the chopper to generate a gating signal to the
insulated gate bipolar transistor (IGBT) acting as a controlled switch of the ELC.

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WAVEFORMS
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Figure 3: Transient waveforms of three-phase SEIG with ELC and three-phase IM
(3.7 kW) and application of 3-kW resistive load.

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WAVEFORMS
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Figure 4: Harmonic spectrum of SEIG terminal voltage. (a) Zero consumer load.
(b) Dynamic load (IM). (c) Dynamic (IM) + static load (3 kW).

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RESULTS
• Experiments are carried out on the developed prototype of the SEIG-ELC system to verify the
validity of the derived mathematical models.
• The induction generator is coupled to a closed loop speed-controlled converter-fed dc motor
drive.
• The test rig consists of a three-phase 7.5-kW 230-V 26.2-A four-pole -connected squirrel-cage
induction machine which is operated as a generator and load consists of a three-phase 3.7-kW
squirrel-cage IM operated as dynamic load and resistive load (3.0 kW) with the developed ELC
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CONCLUSION
• The developed mathematical model of the SEIG with ELC supplying an IM load has been found
suitable for the transient analysis and to assess the rating of the motor, which can be safely started on
the SEIG-ELC system.
• Based on this study, the developed SEIG-ELC system can be installed in the field to feed dynamic
(motors) and static loads.
• It has been observed that the ELC is capable of handling the transients caused by load switching.
• The THD of SEIG voltage is also found within acceptable limits under a reasonable amount of
consumer loads.
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THANK YOU!
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