hybrid controller for renewable energy power plant in stand-alone
TRANSCRIPT
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Hybrid Controller for Hybrid Controller for Renewable Energy Power Plant Renewable Energy Power Plant
in Stand-alone sitesin Stand-alone sites
Dr. Prabodh Bajpai Assistant Professor Electrical Engineering Department, IIT Kharagpur
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Outline
Introduction
Technology aspects
Benefit to the Industry
Commercialization prospective
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Introduction Uncontrolled Renewable energy sources essentially
have random behaviors. eg: Solar, Wind, etc. Power production from Uncontrolled sources is
independent of human intervention Hybrid power systems may contain controlled and
uncontrolled energy sources and energy storage elements with appropriate control systems
Stand-alone hybrid power systems take advantage of the complementary nature in profile of the renewable energy sources
Hybrid power systems ensure continuous and reliable power production
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Possible Renewable Hybrid Energy Systems1) Wind/PV/FC/electrolyzer/battery system 2) Micro-turbine/FC system3) Microturbine/wind system4) Gas-turbine/FC system5) Diesel/FC system6) PV/battery7) PV/FC/electrolyzer8) PV/FC/electrolyzer/battery
system
9) FC/battery, or super-capacitor system
10) Wind/FC system11) Wind/diesel system12) Wind/PV/battery
system13) PV/diesel system14) Diesel/wind/PV system15) PV/FC/ SMES system
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Wind and solar power generation are two of the most promising renewable power generation technologies.
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
DG/Battery Hybrid Solution: Merits Easy to install and low cost on site construction Highly integrated intelligent hybrid power system
for control and protection Inclusion of battery back up reduces the DG size
Saving in diesel and reduction in maintenance of diesel generator
Reduced operating time and enhanced DG life Specially designed deep cycle battery available in
market Rechargeable in a short time, Long cycle life under STC, High DoD (Depth of Discharge)
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
DG based Hybrid Solution : DemeritsDG as energy source has problems of : Pollution
air, noise, heat Dependence of fuel
world-wide increase of oil prices; limited resources in future Transport to the sites
long distances and cost intensive transports Storage of the fuel at site
safety problems - explosions, vandalism No unattended operation is possible
high personnel cost High maintenance cost and limited life-time of DG
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Hybrid Renewable Energy SystemsOn the other hand, the proposed renewable energy
based system helps in: Decrease environmental pollution
Reduction of air emission Energy saving
Reduces production and purchase of fossil fuels Abatement of global warming
CO2 and other green house gases are not produced Socioeconomic development
Develops employment opportunities in rural areas Fuel supply diversity
Diversity of energy carriers and suppliers Distributed power generation
Reduces requirement for transmission lines within the electricity grid
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Challenges Site dependence of renewable sources
Site survey with long term data acquisition & forecasting
Hybrid renewable energy system designConfiguration and sizing of the hybrid system components
with the objectives:Supplying the power reliably under varying atmospheric
conditions Minimizing the total cost of the systemMaximizing the system efficiency by efficient energy flow
management strategiesOptimization through simulation studies under real
operating conditions for a reasonable tradeoff among conflicting design objectives
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
ChallengesEconomic viability
Cost-benefit analysis of hybrid system for reasonable payback period
Real world applicationDesign of power conditioning devices with maximum
power point operation of energy sources Optimal energy management strategies and their
testing with laboratory prototype hybrid controllerDevelopment of hardware and associated software for
field-implementation
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Technology aspects Technology aspects
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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IntroductionSolar PV based renewable power plant with FC,
Battery and DG as backup sourcesHybrid controller to implement the energy
sources changeover logic based on optimal energy management strategy.
Automatic mode of operation in the hybrid controller for FC and DG changeover operations.
Laboratory prototype of hybrid Solar PV-Fuel Cell-Battery-DG system for upto 5 kW load
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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A typical stand-alone PV-Fuel cell-Battery hybrid energy system:
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
System DevelopmentRobustness of the controller to fluctuating weather
conditions and load demand is being rigorously tested, monitored and documented.
Hybrid controller comprises of:◦ Solar DSCAM (master controller) and two slave controllers,
the Fuel Cell DSCAM and DG DSCAM ◦ Individual power conditioning units for SPV, Fuel Cell and
DG system to provide regulated DC output on the DC bus.• The master and slave controllers interact to
provide switching and control signals for the converter units.
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SPV-FC-BATTERY-DG HYBRID ENERGY POWER PLANT
Discharging
ChargingSupply to
Load
PV Power
FC Power
DG Power
SOLAR PV ARRAY (Primary Source)BATTERY BANK ( Back Up Source)
FUEL CELL SYSTEM (Back Up Source)
CONTROLLER
DIESEL GENERATOR (Back Up Source)
LOAD
H2 storage
H2 Supply
Experimental Test Results
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Load 0.75 kW
Load 1 kW
Experimental Test Results
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Load 0.75 kW Load 1 kW
Excess Current Battery ChargingBattery Charging
Merits of TopologyMerits of solar PV charge controller and
Fuel Cell charge controller ◦ Optimal charging of the batteries and maximum power
extraction from solar PV and FC ◦ Supervisory functions to prevent damage to the battery◦ Effective interface to inter connect Solar PV modules, Fuel
Cell, Battery Bank and the load◦ Battery reaches a high state of charge under all operating
conditions◦ Work in tandem with the SMPS based power plant to
optimize the charging capability of the FC/SPV and protect the batteries from overcharge
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Important Features of Topology◦ Use of solid-state devices to control the charging current to
the battery and supply power to the load simultaneously
◦ Blocking devices to prevent reverse current flow from the battery to the FC/SPV during cloudy days or other charging modes
◦ Lightning / transient protection to protect the control circuitry from damage due to excessive voltage
◦ Programmable charging capacity, change over settings and peak power point
◦ Programmable maximum power point tracking (MPPT) logic with the built in embedded logic controller
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Solar resource assessment (SRA) system
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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•Measures weather parameters like• solar insolation (W/m2),• ambient temperature (0C) and• relative humidity(%)
•Weather data at defined intervals is measured using sensors
•Data is sent continuously to a central server through GPRS and is monitored online
Necessity of weather monitoring•Inspecting the feasibility of a site for a solar energy project
•Site comparison and selection based on weather data
•Long term energy assessment helps in effective system sizing and cost minimization
•Helps to predict the performance of SPV
Remote Monitoring SystemRemote Monitoring System
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Sensors
Hybrid Controller
cRIO-9073, Data acquiring, Generating and logging
Monitoring StationRemote PC
Benefit to IndustryBenefit to Industry
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Market potentialExtendable to a generalized solution for any kind of
stand-alone site. Independent of continuous availability of the
renewable source as well as grid power availability.Power converters are modular in nature
For any kind of critical load in stand-alone site◦ Telecom towers, ◦ Cold storage plants, ◦ Hospitals, ◦ Military establishments◦ Fuel stations◦ ATMs
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Commercialization prospectiveCommercialization prospective
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Cost-benefit analysisNet present value = Total lifetime savings –
Total lifetime investmentSavings include revenue generated from the
hybrid PV system by replacing the DG-battery system, the carbon tax benefit and savings in the operational cost of the system.
Investment includes the extra first cost which is the difference between the Capex of the hybrid PV system and the Capex of the DG-Battery system
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Cost-benefit analysis CAPEX for hybrid PV system to meet 4kW
peak load will around 50Lakh INR The lifetime of both the systems considered
to be 30 years. Economic analysis for different scenarios
gives payback period between 5-10 years
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Real world applicationProof of concept verified with a laboratory
prototype
Field site testing with stand-alone load application needs to be done
The Technology Transfer may take place as per One Time License Payment or Revenue Sharing Model or any other criteria mutually agreed
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Component size and priceComponent size and priceComponent Pricing
PV (per Wp) 70
Battery (per kwh) 7,000
H2 tanks(per m3) 400
Fuel cell(per kW) 2,00,000
Diesel Generator (per kW) 33,000
Diesel (per litre) 40
Component Size
PV (Wp) 16500
Battery in hybrid PV system(kwh) 57.6
DG in hybrid PV system (kW) 5
H2 tanks (m3) 120
Fuel cell (kW) 4.56
DG in DG-Battery system (kW) 25
Battery in DG-Battery system( kWh) 105
Financial Assumptions Hybrid PV system:• CAPEX is the total initial cost of the system. OPEX in case1 =1% of CAPEX+ 100% of Battery cost in every 5
years+100% of FC cost every 10,000 hours of operation+ operating cost of FC @Rs 417/hr +operating cost of DG @Rs 50/hr.
OPEX in case2 =1% of CAPEX+ 100% of Battery cost in every 5 years+100% of DG cost in every 15 years + operating cost of FC @Rs 417/hr+ operating cost of DG @Rs 50/hr.
DG/Battery system:• CAPEX is the total initial cost of the system. OPEX =2% of CAPEX+100% of Battery cost in every 5
years+100% of DG cost in every 8 years + operating cost of DG @Rs 50/hr.
The lifetime of both the systems was considered to be 30 years. The present diesel cost was assumed to be Rs 40/litre. The annual escalation in diesel cost was assumed to be @ 10 %
Capex and Opex comparisonsHybrid PV/FC/DG/Battery
system
DG/Battery system
Comparison of savings & investments for hybrid PV/FC/DG/Battery system
NPV and Payback PeriodLonger FC operation Longer DG
operation
With carbon tax benefit 23,344,047 35,527,795
Net present value
Without carbon tax benefit
16,463,765 29,068,754
With carbon tax benefit
5 4
Payback period
Without carbon tax benefit
7 6