Definition and concepts of power electronics and electronics power
conversionApplicationPower semiconductor switches
Power Electronics
DEFINITION: To convert, i.e to process and to control the flow of
electric power by supplying voltages and currents in a form that is
optimally suited for user loads.
Goal of electronics power
conversion systems
To convert electrical energy from one form to another, from the
source to load with highest efficiency, high availability and high
reliability with the lowest cost, smallest size and weight.
Applications
Distributed generation (DG): Effort to tap renewable energy
resourcesRenewable resources (wind and photovoltaic)Fuel cells and
micro-turbinesStorage: batteries, super-conducting magnetic energy
storage, flywheelsPower electronics loads: (air conditioner, fans,
pumps). Variable speed compressor air-conditioning system saves up
to 30% of energy compared to conventional thermostat-controlled
system.Electrical lighting using electronics ballast can boost the
efficiency of fluorescent lamp by 20%.
Applications
Power quality solutionsDual feedersUninterruptible power
suppliesDynamic voltage restorersTransmission and distribution
(T&D)High voltage dc (HVDC) and medium voltage dcFlexible AC
Transmission Systems (FACTS): Shunt and Series compensation, and
the unified power flow controller
Application example
Applications
PE growth
PE rapid growth due to: Advances in power (semiconductor) switches
Advances in microelectronics (DSP, VLSI,
microprocessor/microcontroller, ASIC)New ideas in control
algorithmsDemand for new applications
PE growth: Advances in power (semiconductor) switches
PE growth
PE is an interdisciplinary field: Digital/analogue electronics
Power and energy Microelectronics Control system Computer,
simulation and software Solid-state physics and devices Packaging
Heat transfer
Power semiconductor devices
(Power switches)
Power switches are the work-horses of PE systems.PE switches works
in two states only: Fully on (conducting) Fully off (blocking)Can
be categorised into three group:Uncontrollable: DiodeHalf-
controlled: Thyristor, TRIACFully- controlled: BJT, FET, IGBT,
GTO
Power diode
Types of power diodes
General purpose diode (rectifier diode)standard recoveryFast
recovery diodeReverse recovery time and charge specified. trr is
usually less than 1s, for many less than 100 ns ultra-fast recovery
diode.Schottky diode (Schottky barrier diode-SBD)At lower voltages,
less than 40V, devices of up to 300A are available and the maximum
junction operating temperature is 175C, which is higher than for
conventional silicon pn junction devices.
Static Characteristic
part number
Rated vag current
VF(typical)
tr(max)
Rated max voltage
Fast recovery rectifiers
1N3913
SD453N25S20PC
MUR815
MUR1560
RHRU100120
Schottky rectifiers
Ultra-fast recovery rectifiers
MBR6030L
444CNQ045
30CPQ150
400V
2500V
150V
600V
1200V
30V
45V
150V
30A
400A
8A
15A
100A
60A
440A
30A
1.1V
2.2V
0.48V
1.19V
0.69V
0.975V
2.6V
1.2V
400ns
20s
35ns
6ns
60ns
Special Diode: LED
LEDs available with aluminous efficacy of 1822 lumens per watt
(lm/W).
For comparison, a conventionalincandescent light bulbof 60100
watts emits around 15 lm/W, and standardfluorescent lightsemit up
to 100 lm/W.
on February 3, 2010 about a laboratory prototype LED achieving
208 lumens per watt
Thyristor
Another name: SCRsilicon controlled rectifierThyristor : Opened the
power electronics era
1956, invention, Bell Laboratories
1957, development of the 1st product, GE
1958, 1st commercialized product, GE
Thyristor replaced vacuum devices in almost every power
processing area.
Still in use in high power situation. Thyristor till has the
highest power-handling capability
Appearance and symbol of thyristor
Static Characteristic
Type of thyristor
GTO: The gate turn-off thyristor is an SCR that is turned on by
forward-biasing the cathode junction and turned off by
reverse-biasingLTT: The light triggered thyristor is series
connected in HVDC applications. Five inch wafers, offer 8kV, 3000A.
Turn--on requires about 40mW of light power for 10s. Triac: The
triac comprises two SCR structures
Example:
Two of three thyristor valve stacks used for long distance
transmission of power fromManitoba Hydrodams
