12-12-2012, 12:43 PM
Hybrid Power Systems
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INTRODUCTION
In the last lecture, we studied
Principles of generation of electricity
Faraday’s law
Single phase and 3 phase generators
We also studied the issues in connecting a wind turbine (or a farm) directly to the grid.
We discussed
Voltage stability, connection to a weak grid, islanding, etc.
Communities without access to the grid
In this lecture, we look at communities that do not have access to the grid.
They will have to be self-sufficient, in regard to their energy needs.
Because wind energy is always available due to variations in wind speeds, a comprehensive strategy is needed where wind turbines (and farms) are an important piece of the solution.
These communities will need to plan for
Various forms of electricity production
Storage of energy
Recovery and disposal of excess heat
Power management and control hardware and software
Simulation and forecasting models for setting and maintaining reasonable cost of energy
Diesel Power Systems
Available sources for generation of electricity include diesel generators
These operate at constant RPM, hence called synchronous generators
These can produce steady and reliable supply of energy at required voltages and power levels
These produce excess heat, and pollution
Combined heat and power production (CHP) is being explored, where the excess heat is recovered and used to heat buildings, water, etc.
Other Power Systems
Wind Turbines and Wind Farms
Photovoltaic Cells (Solar Energy)
Fuel Cells
Micro-turbine generators
A comprehensive approach, where two or more of these power generation approaches are used, is called a hybrid power system.
Power Consumption
Power consumption must be carefully managed.
Power consumption may be categorized into
Immediate power needs
Deferred needs (e.g. for making ice, pumping water to a tank, etc)
Optional needs (e.g. charging batteries)
Power management hardware/software will need to distinguish between these needs and meet them.
Power Dumping
Excess power may be dumped into
Static Capacitors
Batteries
Synchronous condensers
Motors that store and release energy, and reduce fluctuations in voltage and power
Excess heat may be used for heating water, heating buildings, etc.