Transcript Hybrid Controller for Renewable Energy Power Plant in Stand

Hybrid Controller for
Renewable Energy Power Plant
in 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
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Introduction

Uncontrolled Renewable energy sources essentially
have random behaviors. eg: Solar, Wind, etc.

Power production from Uncontrolled
independent of human intervention
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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
sources
is
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Possible Renewable Hybrid Energy
Systems
1) Wind/PV/FC/electrolyzer/
9) FC/battery, or supercapacitor system
battery system
10) Wind/FC system
2) Micro-turbine/FC system
11) Wind/diesel system
3) Microturbine/wind system
12) Wind/PV/battery
4) Gas-turbine/FC
system
system
13) PV/diesel system
5) Diesel/FC system
14) Diesel/wind/PV system
6) PV/battery
15) PV/FC/ SMES system
7) PV/FC/electrolyzer
8) PV/FC/electrolyzer/battery
system
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
market
designed deep cycle battery available in
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 : Demerits

DG 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
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Hybrid Renewable Energy Systems

On 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
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Challenges

Site dependence of renewable sources
Site survey with long term data acquisition & forecasting

Hybrid renewable energy system design
Configuration and sizing of the hybrid system
components with the objectives:
Supplying the power reliably under varying atmospheric
conditions
Minimizing the total cost of the system
Maximizing the system efficiency by efficient energy flow
management strategies
Optimization 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
Challenges

Economic viability
Cost-benefit analysis of hybrid system for
reasonable payback period
Real world application

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Design of power conditioning devices with
maximum power point operation of energy sources
Optimal energy management strategies and their
testing with laboratory prototype hybrid controller
Development of hardware and associated software
for field-implementation
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Technology aspects
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Introduction

Solar PV based renewable power plant with FC,
Battery and DG as backup sources
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Hybrid 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
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
A typical stand-alone PV-Fuel cellBattery hybrid energy system:
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
System Development

Robustness 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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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
SPV-FC-BATTERY-DG HYBRID ENERGY POWER PLANT
SOLAR PV ARRAY (Primary Source)
BATTERY BANK ( Back Up Source)
Discharging
PV Power
FUEL CELL SYSTEM (Back Up Source)
LOAD
Supply to
Load
Charging
DIESEL GENERATOR (Back
Up Source)
FC Power
DG Power
H2
Supply
CONTROLLER
H2 storage
Experimental Test Results
60
Load 1 kW
Load 0.75
kW
DG
Operation
Voltage (V)
50
40
30
SPV
Operation
SPV Module-1
Voltage (V)
FC Module-1
Voltage (V)
Battery
Operation
FC
Operation
SPV
Operation
20
10
Battery
Operation
0
DG Module-1
Voltage (V)
System Voltage
(V)
Battery-3 Voltage
(V)
Load Voltage (V)
Time of the day (hr)
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Experimental Test Results
FC
Operation
50
40
SPV Operation
Current (A)
30
Battery
Operation
Battery
Operation
SPV Input Current (A)
SPV Module-1 Current (A)
20
10
SPV
Operation
0
Excess Current
Battery Charging
DG
Operation
Battery Charging
DG Module-1 Current (A)
DG Module-2 Current (A)
-20
-40
FC Module-1 Current (A)
FC Module-2 Current (A)
-10
-30
FC Input Current (A)
System Current (A)
Load 0.75 kW
Load 1 kW
Battery Current (A)
Load Current (A)
Time of the day (hr)
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Merits of Topology

Merits 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
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Solar resource assessment (SRA) system
Necessity of weather
•Measures
weather parameters like
monitoring
• solar insolation (W/m2),
•Inspecting
feasibility of
a site
• ambientthe
temperature
(0C)
andfor
a solar
energy
project
• relative
humidity(%)
•Weather
data at defined
intervals
•Site comparison
and selection
based
isonmeasured
using sensors
weather data
•Data
sentenergy
continuously
to a helps
•Longisterm
assessment
central
server
through
GPRS
and
is
in effective
system
sizing
and
cost
monitored
online
minimization
•Helps to predict the performance of
SPV
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Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
Remote Monitoring System
Sensors
Hybrid Controller
Monitoring Station
Remote PC
cRIO-9073, Data acquiring,
Generating and logging
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Benefit to Industry
Hybrid Controller for Renewable
Energy Power Plant in Standalone sites
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Market potential

Extendable 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
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For any kind of critical load in stand-alone site
◦
◦
◦
◦
◦
◦
Telecom towers,
Cold storage plants,
Hospitals,
Military establishments
Fuel stations
ATMs
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Commercialization prospective
Hybrid Controller for Renewable
Energy Power Plant in Standalone sites
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Cost-benefit analysis

Net present value = Total lifetime savings –
Total lifetime investment

Savings 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
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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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
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Real world application

Proof 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
Hybrid Controller for Renewable Energy Power Plant in Stand-alone sites
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Hybrid Controller for Renewable
Energy Power Plant in Standalone sites
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Component size and price
Component
Size
Component
Pricing
PV (Wp)
16500
PV (per Wp)
70
Battery in hybrid PV system(kwh)
57.6
Battery (per kwh)
7,000
DG in hybrid PV system (kW)
5
H2 tanks(per m3)
400
Fuel cell(per kW)
2,00,000
33,000
40
H2 tanks (m3)
Fuel cell (kW)
120
4.56
DG in DG-Battery system (kW)
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Diesel Generator (per
kW)
Battery in DG-Battery system(
kWh)
105
Diesel (per litre)
Financial Assumptions
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•
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•
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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 comparisons
Hybrid PV/FC/DG/Battery
system
Longer FC operation
Longer DG operation
3,683,2
00
3,060,
000
Capex
Opex
23,600,
932
1,810,0
00
8,973,
982
DG-Battery
DG/Battery system
Capex
26,436,
200
Opex
Capex
Opex
Comparison of savings & investments for
hybrid PV/FC/DG/Battery system
Longer FC operation
Savings
27,284,
132
25,217,
247
Investmen
ts
Longer DG operation
12,657,
182
Savings
37,400,
995
Investmen
ts
NPV and Payback Period
Longer FC operation
Longer DG
operation
With carbon
tax benefit
23,344,047
35,527,795
Without
carbon tax
benefit
16,463,765
29,068,754
With carbon
tax benefit
5
4
Without
carbon tax
benefit
7
6
Net present
value
Payback period