E Power Generation Flashcards
What are 2 common components of a generator?
An armature and a magnet
What is the basic principle of an AC generator?
The magnet is spun near coils
What is the basic principle of an DC generator?
The coils are spun near a magnet
What is the speed of rotation known as?
The frequency
What is a phase?
A pair of poles
What does GCU mean?
Generator control unit
What does PMG mean?
Permanent magnet generator
What does RDA mean?
Rectifier diode assembly
What is the frequency used for an A320/B737?
400Hz
Frequency equation
F = (P x RPM)/120 or F = (PP x RPM)/60
P - number or poles, PP - number of pole pairs
What does CSD mean?
Constant speed drive
Which 2 parameters of the CSD need to be monitored on the flight deck?
- Oil temperature
- Oil pressure
What does IDG mean?
Integrated drive generator
What monitors the IDG and how?
The GCU using a speed sensor and by monitoring output frequency
How does the GCU control frequency?
By using the CSD
What is the phase voltage?
The root mean squared value of peak voltage
What is line voltage?
A calculated measurement to ensure equality between phases and monitor for fault detection
What dos KVA mean?
Kilo-volts x amps
What do KVA’s do?
Measurement of useful power
What does KVAR mean?
Kilo-volts x amp reactive, wasted power
How is KVA managed?
Balanced by CSDU torque
How is KVAR managed?
Balance by the voltage regulator
What does the rectifier do?
Transfers AC current through a diode that cancels out the negative half of the sine wave, creating full wave rectification
How does a DC generator rectify AC output?
Uses a split-ring commutator to cancel out the negative half of the sine wave
What does a voltage regulator do?
Controls the field strength of the electromagnet in the generator, weaker field strength - smaller current output due to reduction in load
What is reverse current protection?
Stops the battery powering the generator when the battery voltage is higher, this stops huge mechanical load on the drive line
What does a starter motor do?
Combines a generator and starter motor in one unit, a controller switches the terminals, thereby switching functions
