International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 5, Issue 3, March 2015) 514 A Fuzzy Logic based Electronic Load Controller for Three Phase Alternator Anurag Yadav 1 , S.N. Singh 2 , Appurva Appan 3 1,3 Masters of Technology, Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India 2 Senior Scientific Officer, Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India Abstract— The present work deals with the use of Fuzzy logic for the implementation of ELC (Electronic Load Controller for three phase alternator). The proposed design of the controller regulates both voltage and frequency of an alternator working in isolated/stand-alone mode. The ELC circuitry designed here is a combination of three phase diode bridge rectifier, IGBT based chopper and a resistive ballast/dump load for dump power consumption whenever there is a mismatch between the generated power and consumer demand. The fuzzy logic based controller is the heart of ELC as it controls the amount of power dumped by varying the duty cycle of the pulses generated based on PWM scheme which are being fed to the IGBT (Insulated Gate Bipolar Junction Transistor) based chopper switch. The proposed ELC model for an alternator has been simulated in MATLAB-SIMULINK environment and is being analysed for both steady-state and transient performance. Keywords—Alternator, Chopper, ELC, Fuzzy logic, PWM, IGBT. I. INTRODUCTION In the present era, electricity has become inevitable for the survival and for the reasons best known to all. Dwindling fossil fuels have posed a formidable challenge before the researchers to meet the growing energy requirements. The major setbacks of the fossil fuels are their rising prices, inability in meeting peak demands, limited stocks, not being environment friendly etc. Fast growing economy and expansion of the energy provisions for the exploding population demands an increment in the share of energy production from renewable energy sources in the overall energy mix [1]. Simultaneously, there is a need to export the power to the remote areas, rural electrification etc. Micro-hydro generation system is quite captivating alternative for remote, hilly areas where there is facile availability of water resources. Power plant operation in such areas demands less operation and maintenance costs, robust construction, exemption from the requirement of state of the art expertise etc. [2]. Alternators/Synchronous generators appear to be an apt candidate due to its advantages viz. less maintenance, robust construction, inherent short-circuit and overloading protection, better frequency and voltage regulation, dual- mode flow of power i.e. it can both import and export power depending upon the type of excitation. In isolated/stand-alone mode there are frequent and large perturbations in the voltage and frequency which are required to be controlled in order to prevent the damage to the load as well as to the machine. Conventional hydraulic governor system is quite big in size, sophisticated and is a costly affair. Moreover, efficiency considerations also make it impractical to be used in micro-hydro governing system [3]-[4]. Aforesaid arguments in collusion demands for an efficient, cheap and dynamic governing system for control of voltage and frequency [5]. In the proposed scheme, ELC is being paralleled with the consumer load across the alternator terminals. ELC circuitry is composed of three-phase diode bridge rectifier, IGBT based chopper switch and a ballast load [1]. The fuzzy logic is implemented for the PWM generation scheme for the pulses that are fed to the chopper switch for controlling the dump power. Pulses are of varying duty cycle in accordance with the consumer load variations. The idea of ELC is to maintain constant load on the alternator. Thus, in the scheme alternator always runs at rated conditions in the steady-state. The ELC is being analysed for three phase balanced resistive load across the alternator terminals [6]. II. ALTERNATOR MODEL WITH ELC Fig. 1: Per phase equivalent circuit model of alternator
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International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 5, Issue 3, March 2015)
514
A Fuzzy Logic based Electronic Load Controller for Three
Phase Alternator Anurag Yadav
1, S.N. Singh
2, Appurva Appan
3
1,3Masters of Technology, Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee, 247667,
Uttarakhand, India 2Senior Scientific Officer, Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee, 247667,
Uttarakhand, India
Abstract— The present work deals with the use of Fuzzy
logic for the implementation of ELC (Electronic Load
Controller for three phase alternator). The proposed design of
the controller regulates both voltage and frequency of an
alternator working in isolated/stand-alone mode. The ELC
circuitry designed here is a combination of three phase diode
bridge rectifier, IGBT based chopper and a resistive
ballast/dump load for dump power consumption whenever
there is a mismatch between the generated power and
consumer demand. The fuzzy logic based controller is the
heart of ELC as it controls the amount of power dumped by
varying the duty cycle of the pulses generated based on PWM
scheme which are being fed to the IGBT (Insulated Gate
Bipolar Junction Transistor) based chopper switch. The
proposed ELC model for an alternator has been simulated in
MATLAB-SIMULINK environment and is being analysed for