Download Power Electronics for Active Magnetic Bearings

Power Electronics for Active
Magnetic Bearings
Introduction
Reference
Power
Circuits
Controller D/A converter
Electromag
nets +
Mechanics
Displacement
Sensors
A/D converter
Digital Control
Conditioners
Introduction
Applications
Compressor
Gas Turbine
Motor
Turboexpander
Offshore
Power Electronics
3
4
total : 6 freedom degrees
1
5
6
AMB control system
2
1
2
3
4
5
6
5 AMB axis control
torque control
Analog Circuits
R = resistor,
L = inductance,
C = capacitor.
+ V1
30V
D1
Lamb
200mH
DIODE
• Transistors operating
in the active mode.
Iamb = K * Ib1
Ib1
10mA
R1
1k
Q1
NPN
Analog Circuits
• Push Pull circuit:
Vpos= V+
Vneg= VBipolar Output Currents
Analog Circuits
• Improved Push Pull circuit:
Vpos= V+
Vneg= VBipolar Output Currents
Analog Circuits
• Operational Amplifiers
Vout = Gain * [(+v) – (-v)]
OPAMP
ideal
Ideal Gain = infinite
Input Impedance = infinite
Using auxiliary passive components, different transfer functions can
be implemented, by instance:
Kp,
Kp(1 + Td*s),
Kp(1+Ti/s), …
Analog Circuits
Digital Circuits
Combinational circuits: logical gates,
encoders, multiplexers, etc
Sequential circuits: flip-flops, counters,
memories, etc
Hybrid circuits:
Analog-Digital converter
Digital-Analog converter
Power Circuits
• Linear Type:
Use of opamp´s and power transistors:
BJT,Mosfet,IGBT
• Switched Type: two states of operation:
on (short) and off (open)
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
Switched Power Circuits
To be continued
Application in compressors
HP=High pressure , LP=Low pressure
The challenge
Coupling
Coupling
Motor
Coupling
Gearbox
Shaft Seals
Conventional Compressor Train
Goal
Goal
Keep
Keeponly
onlywhat
whatisis
essentially
neccessary!:
essentially neccessary!:
LP Compressor
HP Compressor
HP Compressor
Motor
••Motor
Motor
••Shaft
Shaft
••Impellers
Impellers
••Bearings
Bearings
HOFIM Sealed
LP Compressor
Application in compressors
HP=High pressure , LP=Low pressure
Oil-free Compression - Product Family
HOFIM Sealed
Motor Power Cables
(junction box removed
for visibility)
Cooling Gas Control
Valve & Pressure Switches
Cooling Gas
Filter (double)
HP Barrel
Compressor
High Speed
Motor
Common
Base Frame
Drains and Balance
Piston Return Lines
LP Barrel
Compressor
HOFIM Sealed in
tandem arrangement:
Nüttermoor for EWE