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Power Electronics in New and Renewable Energy Systems. Mohammad A. Abusara Lecturer in control and Power Electronics Renewable Energy Research Group College of Engineering, Mathematics, and Physical Sciences. Outline. Microgrid Grid Connected Interleaved Inverter
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Power Electronics in New and Renewable Energy Systems Mohammad A. Abusara Lecturer in control and Power Electronics Renewable Energy Research Group College of Engineering, Mathematics, and Physical Sciences
Outline Microgrid Grid Connected Interleaved Inverter Exhaust Heat Energy Recovery Systems Marine Renewable Energy
Microgrid System 35kWHr lithium-ion batteries (60kVA Inverter) 100kW micro Gas Turbine
Microgrid Challenges and Features Challenges • Maintain stability during connection, disconnection, load application/shedding • Good Load sharing in island mode • Good current quality in grid-connected mode Features • Seamless transfer from grid-connected mode to island mode and vice versa • Improved current quality • Improved transient response
Microgrid-Practical Results The effect of virtual impedance on improving current THD
Interleaved Concept • One channel is replaced by a number of channels connected in parallel • Switching instants are phase shifted equally over a switching period • Introduced for telecommunication power supplies (low voltage high current)
Interleaved Inverter- Advantages Smaller Power Switches Smaller capacitors Smaller Inductor
Novel DC/AC Grid Connected Interleaved Inverter • Advantages over 2-level topology • Smaller C and hence so high output impedance to voltage harmonics (better current THD) • No need for a second L • Smaller in size
Passive Damping • For active damping • Sampling frequency (35kHz) is only 1.47 to 3.2 times the natural resonance frequency • Passive damping is possible (small capacitor current thanks to interleaved topology)
Passive Damping R Root locus, R = 0 ohm Root locus, R = 0.5 ohm The varying parameter in the Root Locus is the grid impedance
Controller Design Proportional Controller K(z) =10 Phase Lag Controller
Robust Digital Controller Immunity to Grid Impedance Variations Excellent Current Quality (THD=2.3%)
Energy Recovery System Although it is a dominant prime mover and one of the most efficient power sources, a typical modern turbocharged Diesel engine still wastes significant amounts of fuel energy. The exhaust waste heat energy can be recovered and converted into useful electrical power
Components of Exhaust Recovery System • Fuel Saving 5-7% • Power Boost 10-15% Turbine + High speed alternator Power Electronics
Customers Off road vehicle Stationary power plants On road trucks
Marine Renewable Energy Systems Tide Wave