DOC AIRBUS | AMM A320FINTEGRATED DRIVE GENERATOR SYSTEM (IDG, GCU) - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
Each engine (HP rotor) drives its associated IDG through the accessory gearbox. The drive speed varies according to the engine rating.
The IDG provides a 115/200 VAC, 3-phase, 400 Hz AC supply at the Point of Regulation (POR).
The IDG has two parts: the Constant-Speed Drive (CSD) and the generator.
The hydromechanical Constant-Speed Drive drives the AC generator at constant speed.
** ON A/C NOT FOR ALL Each engine (HP rotor) drives its associated IDG through the accessory gearbox. The drive speed varies according to the engine rating.
The IDG provides a 115/200 VAC, 3-phase, 400 Hz AC supply at the Point of Regulation (POR).
The IDG has two parts: the Constant-Speed Drive (CSD) and the generator.
The hydromechanical Constant-Speed Drive drives the AC generator at constant speed.
2. Component Location
The IDG is installed on the engine gearbox pad.
It is attached by means of a Quick Attach Detach device (QAD),
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL The IDG is installed on the engine gearbox pad.
It is attached by means of a Quick Attach Detach device (QAD),
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 5XT | P/BSW-ELEC/IDG 1 | 35VU | 210 | 24-21-00 | |
| 6XT | P/BSW-ELEC/IDG 2 | 35VU | 210 | 24-21-00 | |
| 4000XU | IDG | 435 | 24-21-51 | ||
| 4210KS | HARNESS-IDG POWER FEEDER | 410 | 73-25-00 | ||
3. System Description
A. Integrated Drive Generator (IDG)
The IDG converts variable speed shaft power directly into constant frequency 400 Hz AC electrical power.
This is accomplished by the Constant Speed Drive (CSD) which drives the AC generator at constant speed.
The AC generator produces thus constant frequency power.
The IDG converts variable speed shaft power directly into constant frequency 400 Hz AC electrical power.
This is accomplished by the Constant Speed Drive (CSD) which drives the AC generator at constant speed.
The AC generator produces thus constant frequency power.
B. Function of the Generator Control Unit (GCU)
Each GCU controls its dedicated IDG:
The main functions for the regulation and protection of the IDG are:
Each GCU controls its dedicated IDG:
- IDG 1 : GCU 1,
- IDG 2 : GCU 2.
The main functions for the regulation and protection of the IDG are:
- regulation of the generator voltage at Point Of Regulation (POR),
- regulation of the generator speed,
- monitoring and protection of the system.
C. Function of the IDG Pushbutton Switches
If an IDG is faulty (overheat or abnormal oil low pressure), the FAULT legend comes on. The pilot must then open the safety guard and push the IDG pushbutton switch. This action results in the mechanical disconnection of the faulty IDG.
If an IDG is faulty (overheat or abnormal oil low pressure), the FAULT legend comes on. The pilot must then open the safety guard and push the IDG pushbutton switch. This action results in the mechanical disconnection of the faulty IDG.
NOTE: With engine stopped, the IDG cannot be disconnected. An underspeed condition inhibits the disconnection.
4. Power Supply
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5. Interface
A. Generator Control Unit
(1) Input data
Each GCU receives the following signals from its dedicated IDG:
Each GCU receives the following signals from its dedicated IDG:
- oil inlet temperature,
- oil outlet temperature,
- low oil pressure,
- PMG 3 phase output voltage,
- CT 3 phase signal.
(2) Output data
Each GCU provides the following output analog data to the SDACs, through the ARINC 429 link:
It provides also to the SDACs the following discrete information through ARINC 429 link:
Each GCU provides the following output analog data to the SDACs, through the ARINC 429 link:
- IDG oil output temperature,
- IDG oil inlet temperature,
- AC load at POR,
- AC frequency (phase A)
- AC voltage (phase A) at POR.
It provides also to the SDACs the following discrete information through ARINC 429 link:
- overload warning,
- generator fault,
- IDG disconnect status,
- IDG disconnect pushbutton position,
- IDG oil outlet overheat,
- IDG oil low pressure,
- GEN pushbutton switch position.
6. Description
A. Description of the IDG
(1) Electrical circuit
- hook-up of the electrical wiring,
- location of the electrical connectors.
(2) Maintenance
- oil replenishing,
- oil drainage,
- oil level check,
- filter,
- disconnect reset handle.
(3) Inspection
- clogging indicator of the scavenge oil filter on the IDG oil-out line.
(4) Cooling system
- oil in port,
- oil out port.
B. Quick Attach Detach (QAD) Adapter
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL
The IDG is installed on the engine gearbox pad. It is attached by means of QAD device with a tension bolt.
IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL IDG Attachment to the Gearbox ** ON A/C NOT FOR ALL The IDG is installed on the engine gearbox pad. It is attached by means of QAD device with a tension bolt.
C. Drive
The speed conversion components consist of the gear differential and the hydraulic trim unit. The variable speed shaft power is provided by the engine gearbox to the IDG input shaft which is directly coupled to the carrier shaft of the differential.
The variable displacement hydraulic unit is driven by the carrier shaft at a direct ratio of input speed. The variable displacement hydraulic unit is hydraulically coupled to a fixed displacement hydraulic unit which is mechanically coupled to the trim ring gear of the differential.
The speed and direction of rotation of the fixed displacement hydraulic unit and hence the trim ring gear is regulated by an electronic controlled servo valve.
The servo valve ports oil to a control piston to position the variable wobbler and control the rate and direction of oil flow from the variable to fixed hydraulic units. Speed summing is accomplished in the differential by adding or subtracting the trim speed of the trim ring gear to the meshing planet gear which is orbited as a function of input speed by the carrier shaft.
The second or output planet is in mesh with the first planet and the output ring gear. The output gear is thereby made to rotate at a constant speed. Since the output ring gear is meshed with the generator drive gear, constant shaft speed (24,000 rpm) is converted directly into 400 Hz constant frequency AC power which is available at the IDG power terminals.
The speed conversion components consist of the gear differential and the hydraulic trim unit. The variable speed shaft power is provided by the engine gearbox to the IDG input shaft which is directly coupled to the carrier shaft of the differential.
The variable displacement hydraulic unit is driven by the carrier shaft at a direct ratio of input speed. The variable displacement hydraulic unit is hydraulically coupled to a fixed displacement hydraulic unit which is mechanically coupled to the trim ring gear of the differential.
The speed and direction of rotation of the fixed displacement hydraulic unit and hence the trim ring gear is regulated by an electronic controlled servo valve.
The servo valve ports oil to a control piston to position the variable wobbler and control the rate and direction of oil flow from the variable to fixed hydraulic units. Speed summing is accomplished in the differential by adding or subtracting the trim speed of the trim ring gear to the meshing planet gear which is orbited as a function of input speed by the carrier shaft.
The second or output planet is in mesh with the first planet and the output ring gear. The output gear is thereby made to rotate at a constant speed. Since the output ring gear is meshed with the generator drive gear, constant shaft speed (24,000 rpm) is converted directly into 400 Hz constant frequency AC power which is available at the IDG power terminals.
D. Generator
The generator is a three stage assembly which includes three machines connected in cascade.
The first machine (Pilot Exciter (PE)) is a twelve pole Permanent Magnet Generator (PMG).
Its rotor is constructed of small Rare Earth Cobalt magnets. The output from the PE stator winding:
The first machine (pilot exciter (PE)) is a twelve pole permanent magnet generator (PMG).
Its rotor is constructed of small Rare Earth Cobalt magnets. The output from the PE stator winding :
This output feeds the main rotor winding.
The DC output thus produced supplies the rotating field system of the third machine.
The third machine (main alternator) receives excitation for the rotating salient four pole field from the rectified output of the main exciter.
The main alternator has a three-phase star-connected stator-winding. The three phases and neutral are taken to the generator output terminal block.
The generator is designed for use with an external voltage regulator forming part of the GCU.
The GCU:
The generator is a three stage assembly which includes three machines connected in cascade.
The first machine (Pilot Exciter (PE)) is a twelve pole Permanent Magnet Generator (PMG).
Its rotor is constructed of small Rare Earth Cobalt magnets. The output from the PE stator winding:
- has a generator excitation function,
- provides power for other components of the electrical system which comprises the generator (supply of the GCU, EGIU, and the external relays and contactors). The generator is thus "self-flashing" and "self-sufficient".
The first machine (pilot exciter (PE)) is a twelve pole permanent magnet generator (PMG).
Its rotor is constructed of small Rare Earth Cobalt magnets. The output from the PE stator winding :
- has a generator excitation function
- provides power for other components of the electrical system of which the generator forms part (supply of the GCU and the external relays and contactors). The generator gets thus "Self-flashing" and "Self-sufficient".
This output feeds the main rotor winding.
The DC output thus produced supplies the rotating field system of the third machine.
The third machine (main alternator) receives excitation for the rotating salient four pole field from the rectified output of the main exciter.
The main alternator has a three-phase star-connected stator-winding. The three phases and neutral are taken to the generator output terminal block.
The generator is designed for use with an external voltage regulator forming part of the GCU.
The GCU:
- rectifies the output of the pilot exciter,
- regulates the excitation current to the main exciter field winding.
E. IDG Oil System
(1) IDG Cooling
An engine oil cooler located close to the IDG enables IDG oil cooling.
The schematic of the IDG oil circuit is shown on figure
An engine oil cooler located close to the IDG enables IDG oil cooling.
The schematic of the IDG oil circuit is shown on figure
(2) IDG Cooling
An engine fuel/oil cooler cools the IDG oil and limits the IDG inlet temperature to 127 deg.C. Engine oil and IDG oil both go through the fuel/oil cooler but do not mix.
An engine fuel/oil cooler cools the IDG oil and limits the IDG inlet temperature to 127 deg.C. Engine oil and IDG oil both go through the fuel/oil cooler but do not mix.
NOTE: The normal IDG oil inlet temperature is between 40 deg.C to 105 deg.C
(3) IDG oil system operation
The IDG has a self contained oil system except for the heat-exchanger.
Positive displacement scavenge pumps deliver the oil (via the IDG filter) to the aircraft heat exchanger and return it to the IDG.
The charge oil supply of cleaned, cooled deaerated oil is provided as a bus.
This oil supply feeds :
The dearator supercharges the inlet of the charge pump with solid oil.
The charge pump pressurizes the oil against the charge relief valve.
It provides thus regulated supply pressures to :
The IDG has a self contained oil system except for the heat-exchanger.
Positive displacement scavenge pumps deliver the oil (via the IDG filter) to the aircraft heat exchanger and return it to the IDG.
The charge oil supply of cleaned, cooled deaerated oil is provided as a bus.
This oil supply feeds :
- the differential hydraulic units
- the generator
- the governor
- the control piston
The dearator supercharges the inlet of the charge pump with solid oil.
The charge pump pressurizes the oil against the charge relief valve.
It provides thus regulated supply pressures to :
- the hydraulics
- the controls
- the differential
- the generator
- the various lubrication and cooling nozzles.
(4) IDG oil system operation
The oil enters the IDG at the opposite side of the drive end through the input (I/P) filter and is ported to:
The oil supplied to the differential gear is also used to spray cool the PMG stator and lube the disconnect spline.
The input housing has rectangular grooves cut around the main generator stator core in which oil flows to cool the stator and maintain a lower IDG surface temperature.
The charge pump draws in the oil flow at its suction port and intensifies its pressure.
The charge oil is then used:
The oil entering the rotor is distributed for cooling at level of:
This oil used is then either ported directly to the deaerator or leaked to the IDG sump where it is scavenged and pumped to the deaerator. The oil is deaerated and then ported to the supply pump.
There it runs through the filter into the external system lines for cooling.
The oil enters the IDG at the opposite side of the drive end through the input (I/P) filter and is ported to:
- the differential gear,
- input seal,
- charge pump,
- generator stator and rotor.
The oil supplied to the differential gear is also used to spray cool the PMG stator and lube the disconnect spline.
The input housing has rectangular grooves cut around the main generator stator core in which oil flows to cool the stator and maintain a lower IDG surface temperature.
The charge pump draws in the oil flow at its suction port and intensifies its pressure.
The charge oil is then used:
- as a motive flow in the hydraulic and control system,
- for cooling and lubrication of the hydraulic parts.
The oil entering the rotor is distributed for cooling at level of:
- the exciter and main generator rotors,
- exciter and main generator windings,
- the diodes.
This oil used is then either ported directly to the deaerator or leaked to the IDG sump where it is scavenged and pumped to the deaerator. The oil is deaerated and then ported to the supply pump.
There it runs through the filter into the external system lines for cooling.
(5) Oil filter differential pressure indicator
There is a differential pressure indicator to show when the filter element is clogged. The sensing device for the differential pressure is automatically neutralized during cold oil running conditions: this avoids spurious indications due to high oil viscosity. Similarly, a cooler by-pass valve is fitted in the IDG.
When pressure rises, the valve opens so the cooler is by-passed during cold oil operation.
A scavenge pump relief valve limits the supply pressure of the scavenge system.
A vent valve releases internal case pressure if necessary.
There is a differential pressure indicator to show when the filter element is clogged. The sensing device for the differential pressure is automatically neutralized during cold oil running conditions: this avoids spurious indications due to high oil viscosity. Similarly, a cooler by-pass valve is fitted in the IDG.
When pressure rises, the valve opens so the cooler is by-passed during cold oil operation.
A scavenge pump relief valve limits the supply pressure of the scavenge system.
A vent valve releases internal case pressure if necessary.
(6) Oil filter differential pressure indicator
The scavenge filter is fitted with an oil filter differential pressure indicator. The indicator shows when the filter element requires replacement. The sensing device for the oil filter differential pressure indicator is automatically inhibited during cold oil running conditions. This avoids spurious operation due to high oil viscosity.
The scavenge filter is fitted with an oil filter differential pressure indicator. The indicator shows when the filter element requires replacement. The sensing device for the oil filter differential pressure indicator is automatically inhibited during cold oil running conditions. This avoids spurious operation due to high oil viscosity.
(7) IDG oil pressure fill
A quick fill coupling installed on the transmission casing enables pressure filling or topping up the unit with oil. The oil thus introduced flows to the transmission via the scavenge filter and external cooler circuit. This ensures:
A quick fill coupling installed on the transmission casing enables pressure filling or topping up the unit with oil. The oil thus introduced flows to the transmission via the scavenge filter and external cooler circuit. This ensures:
- the priming of the external circuit,
- the filtration of any oil introduced.
NOTE: Motoring is not necessary for oil level check or oil replenishment.
(8) Oil level check
The oil level can be read on the vertical sight glass.
Servicing is performed according to the oil level position in zones determined by different colors (red, yellow, green).
The oil level can be read on the vertical sight glass.
Servicing is performed according to the oil level position in zones determined by different colors (red, yellow, green).
F. Description of the Electrical Connectors
There are three differently sized electrical connectors on the IDG.
There are three differently sized electrical connectors on the IDG.
(1) Connector A
The following internal components are connected to it:
The following internal components are connected to it:
- the Main Exciter (ME),
- 3 current transformers,
- disconnect solenoid.
(2) Connector B
The following internal component are connected to it:
The following internal component are connected to it:
- the PMG stator,
- the oil-in and oil-out temperature bulbs,
- the servo valve.
(3) Connector C
Only one internal component is connected to it:
Only one internal component is connected to it:
- the charge pressure switch.
G. Leading Particulars of the IDG
(1) Speed range
Minimum speed : 4900 RPM
Maximum speed : 9120 RPM
Minimum speed : 4900 RPM
Maximum speed : 9120 RPM
(2) Direction of rotation
Clockwise looking from IDG input.
Clockwise looking from IDG input.
(3) Ambient temperature
Normal operating temperature : 40 °C to 105 °C
Normal operating temperature : 40 °C to 105 °C
(4) Max mass
57.42 Kg.
57.42 Kg.
7. Operation/Control and Indicating
IDG System - Generator Drive Control and Indicating ** ON A/C NOT FOR ALL
IDG System - Generator Drive Control and Indicating ** ON A/C NOT FOR ALL
IDG System - Generator Drive Control and Indicating ** ON A/C NOT FOR ALL IDG System - Generator Drive Control and Indicating ** ON A/C NOT FOR ALL A. Monitoring of the Oil System Operation
Oil temperature sensors monitor oil-in and oil-out temperatures: they allow overheat detection.
A pressure switch operates in the event of a loss of charge oil pressure.
In both cases (overheat and loss of pressure), a warning is provided to the cockpit, (FAULT legend and ECAM warning):
The oil-out temperature is displayed on the ECAM electrical page.
Oil temperature sensors monitor oil-in and oil-out temperatures: they allow overheat detection.
A pressure switch operates in the event of a loss of charge oil pressure.
In both cases (overheat and loss of pressure), a warning is provided to the cockpit, (FAULT legend and ECAM warning):
The oil-out temperature is displayed on the ECAM electrical page.
NOTE: When the oil temperature reaches a predetermined value, an advisory mode is shown on the ECAM
B. Disconnection of the IDG
On the ELEC section, the amber FAULT legend of the IDG 1(2) pushbutton switch comes on and the master warning system starts if:
The IDG disconnection is irreversible in flight. The connection of the system is then possible only on the ground with engines stopped.
On the ELEC section, the amber FAULT legend of the IDG 1(2) pushbutton switch comes on and the master warning system starts if:
- There is an oil overheat (when the temperature of the oil that comes out of the IDG is high).
- The oil pressure decreases but not because of the drive underspeed.
The IDG disconnection is irreversible in flight. The connection of the system is then possible only on the ground with engines stopped.
- The FAULT legend of the IDG 1(2) pushbutton switch cannot be on during the engine shutdown (underspeed).
- If there is an oil overheat or if the oil pressure decreases, the FAULT legend of the IDG 1(2) pushbutton switch goes off when the IDG disconnection occurs (speed less than 2000 rpm).
C. Reconnection of the IDG
A mechanical reset handle is fitted to the IDG.
The handle is used to reconnect the drive while the engine is stationary on the ground.
A mechanical reset handle is fitted to the IDG.
The handle is used to reconnect the drive while the engine is stationary on the ground.
D. Oil filter
A clogged filter indication is provided by a local visual pop out indicator. The indicator is installed opposite the drive end of the IDG.
A clogged filter indication is provided by a local visual pop out indicator. The indicator is installed opposite the drive end of the IDG.