This magnetism in turn induces voltage into an armature which then carries electrical power to generator control unit (GCU). This power is rectified and conducted to exciter field winding. This then induces voltage into exciter output winding field. This output is rectified to DC and flows through the output field winding and it’s induced into the main output coils. A voltage regulator is incorporated to control the voltage generated by the system depending on the load and the engine speed. It consists of a Generator Control Unit that ensures that all the 3 phases produce equal voltages or the difference is within limits. It also has provision to ensure that the frequency is maintained within the desired limits. Over voltage (OV) - When the voltage at the point of reference (POR). Is above 125V, there is a faculty voltage regulator, and the generator control relay (GCR) is de-energized. Q2. Explain with an aid of a diagram how an integrated drive generator (IDE) works. The IDE has 2 main parts. i. A drive. ii. A brushless AC generator. The drive part makes sure that the generator operates at a fixed rpm, regardless of the engine rpm and generator load. The IDG input shaft drives the generator through a reduction gearing and a differential gear. When the generator operates at 12000 rpm the generator frequency is 400 Hz. When the input shaft increases or decreases the frequency of the generator increases or decreases too. This deviation from 400 Hz is detected in the GCU which supplies an electrical signal to a servo valve in the IDG drive part. This servo valve in turn controls through a control cylinder a hydraulic unit which starts to operate in an anti/clockwise direction. Since the hydraulic unit is connected to another input of the differential gear, the generator rpm increase or decrease is less than the rpm fluctuation on the input shaft. As a result, the generator frequency stays approximately constant. The hydraulic unit operates on 240 up to 280 psi. This charge pressure is made by a charge pump and charge relief valve; the charge oil is also used to cool the generator. The oil flow is between 34 and 53 liters. Drain oil from the generator and sump is supplied through a scavenge filter to an external oil cooler by three pumps , which are driven by the accessory drive gear on the differential gear These pumps are generator scavenge pump, sump scavenge and inversion scavenge pump. The accessory drive gear also drives the de-aerator and charge pump. The return oil from the cooler passes the de-aerator and it goes back to the charge pump. Q3. Explain how a transformer rectifier (TRU) works. The TRU as the name suggests is both a transformer and a rectifier. The transformer steps down 12000 V to 28 V while the rectifier converts the 400Hz AC power to DC. The 3 phase AC is routed to the primary side of the transformer and is in connected in star order. Two secondary sides are at the transformer. SEC 1 is in star order while SEC 2 is in delta order. The output of the secondary side is rectified by full wave rectifier circuits. The purpose of the two different secondary sides with separate rectification is to have less ripple of the rectified 28V DC power output. If the temperature of the rectifiers is over a certain limit, overheat switches providing signals to the monitor circuit in the TRU causes the TRU
Name: Instructor: Course: Date: Q1. Explain how aircraft three-phase electrical generator works. An aircraft AC generator consists of three main parts namely: 1. Alternator. 2. Voltage regulator. 3. Main Generator. The alternators used in aircrafts are mostly brushless with a cooling system incorporated and consists of two main parts; the stator and the rotor…
This has specific uses in reverse engineering where a well designed model can be reverse engineered to ascertain its dimensions. This is ideal for manufacturing components where the technical backup to produce such a product may be lacking. However, in the field of quality and process control, this could be used to ascertain the number of defective parts or the number of components that are not in line with the required set of standard dimensions.
17 Task1: Engine Management Systems Describe the two types of electronic engine management systems that can be found on modern aircraft General Description of Supervisory Engine Management Supervisory engine management was developed along with the advent of computer technology with a view to reduce the cognitive load of pilots and to extend the engine life (Nagabhushana and Sudha 187).
The turbine engine generates high-speed gas, which provides the power for the pneumatic system. The external air passes through multi stage axial compressor, which is driven by the engine turbine. From the multi stage compressor the pressurized air is delivered to the engine turbine.
Despite the high standard of commensurate compensation, incentives, and benefits, plus is the dignity of aircraft airworthiness maintenance which has resulted in having one of the best safety records, is this persistent increasing demand. It appears that, the prerequisite for qualifying enthusiast has actually drawn up the boundaries in this profession.
It has received several letters from the Department of Defense about quality deficiencies and the DoD is now threatening to withhold partial payment unless quality improves by 20% within six months. Workers estimate that 20% of their time is spent repairing
er which obtains information on the various engine operating parameters and acts upon a hydro-mechanical fuel control system within a limited authority whereby limiting actions, such as TGT limiting, torque limiting in turboprop engines and combustor pressure limiting during
On the rotary shaft is the first stage generator, excited by the stationary field. This generates an ac current which is rectified by diodes mounted on the shaft to supply current to the main field for excitation of the second stage/ main stage stator output windings. A
Typically, it is not enough to simply compare resistance. This is due to the fact that value between batches of lead-acid batteries can vary by 8%. As a result of this relatively wide tolerance, resistance method is effectively applicable in