1. Title of the invention
Electrically Controlled Pressure Refueling on ground using Internal Battery.

2. Field of invention
It is an Electrical scheme made for aircraft refueling on ground with the help of Internal aircraft battery.

3. Use of invention
This scheme has provided a significant improvement in the existing process of refueling. This scheme is extremely useful in places where Ground Power unit is not available for refueling. As a safety measure, it is recommended to avoid simultaneous usage of Ground power receptacle and Ground refueling port. This invention facilitates aircraft refueling using internal battery due to which simultaneous usage of Ground power receptacle and Ground refueling port gets avoided. This invention enables the refueling by usage of battery source and hence ensures that there is no power interruption during the Pressure refueling process. This operation can be done by pilot with a reduced number of supporting personnel. Aircraft battery is float charged and continuously gets charged during normal flight. In this scheme, battery discharges during refueling process. This improves life of battery as well.

4. Prior art
In Prior scheme, aircraft refueling had to be done using Ground power unit. This poses a serious limitation of availability of Ground power unit. In war scenario, where aircraft gets stranded in remote locations, ground power unit (GPU) may not be available, due to which refueling operation will not be possible.

5. Draw backs of prior art
Drawbacks of prior art are summarized below:

(a) Ground power unit is required for refueling operation. Hence refueling not possible at places where GPU is not available.

(b) During refueling process, Ground power receptacle and Ground refueling port have to be simultaneously active. This is undesirable from safety perspective.
During refueling process, Ground power receptacle and Ground refueling port have to be simultaneously active. This is undesirable from safety perspective.

(b) More number of trained ground crew personnel is required to carry out the refueling operation.

(c) Refueling process gets aborted during power interruption.

6. Comparison between prior art and present invention Factors Prior art Present invention Ground power unit availability Required Not required Simultaneous usage of GPU and Simultaneously used Not used simultaneously GRP port Safety ensured Less More Operating staff Trained ground crew personnel Pilot operated should be available Battery life No improvement Improved Power interruption Possible Not possible

7. Aim of the invention
Aim of this invention is to carryout aircraft refueling without using Ground power unit. This scheme enables to carryout refueling operation by using aircraft internal battery.

8. Summary of the present invention
Aircraft refueling on ground is carried out using internal battery. Switch provided in Ground refueling panel has two positions- GROUND and FLIGHT. When switch is selected to "GROUND" position, Relays in the circuit get energized and Battery supply reaches Ground refueling panel. This activates the command for refueling. When switch is selected to "FLIGHT" mode, power supply through battery is cut off. "FLIGHT" mode wiring is provided through Battery switch to ensure that during FLIGHT, when

Battery switch is ON, the power supply through Battery is cut off. This ensures that no refueling through battery is possible in flying condition.

9. Brief description of drawings
Fig-l shows the schematic of the electrically controlled pressure refueling scheme with the help
of internal battery.

Pressure refueling electrical circuit consists of
1. Battery source
2. Circuit breakers
3. Ground Refuel Panel
4. Refueling relay & Relay -1
5. Data acquisition and Health monitoring system
6. Power supply unit

A Switch is provided in Ground refueling panel that has two positions- GROUND and FLIGHT. When switch is selected to "GROUND" position, Ground refueling panel sends a signal to energize Refueling relay. When Refueling relay is energized, battery supply is provided to Ground refueling panel through another relay "Relay-1". Relay-1 energizing is through Battery switch in ON position. On ground, when battery switch is OFF position, Relay-1 is de-energized and Battery supply is provided to Ground Refueling panel, enabling refueling on ground.

When the aircraft is ready for flight, switch is put to FLIGHT mode. Data acquisition and Health monitoring unit withdraws +28V DC supply. Therefore Refueling relay gets de-energized, cutting off battery supply. To ensure doubly, Relay-1 energization is provided through battery switch in ON position. In FLIGHT mode, battery switch is in "ON" position, which energizes Relay-1, thereby cutting off battery power to Ground refuel panel.

10. Statement of invention
Product of this invention is a pressure refueling scheme. The function of this scheme is to enable pressure refueling of aircraft on ground by using internal battery. This invention is applicable for fighter aircraft refueling at places where ground power unit is not available.

11. Detailed description of invention
In the conventional method, ground power was used for pressure refueling. Usage of Ground power receptacle and Ground Refueling port at the same time is not advisable as a safety requirement. Hence this scheme was designed to permit pressure refueling using internal battery.

Ground Refuel panel is provided with a switch with positions GROUND/FLIGHT. When refueling needs to be done on ground mode, this switch is selected to GROUND mode. In GROUND mode, Ground refueling panel provides +28V DC supply. This supply is provided to energizing coil of Refueling relay. Refueling relay gets energized. Power supply from Battery is made available to Ground Refueling Panel (GRP) through energized contacts of Refueling Relay.

One additional Relay-1 is wired to cut off the power supply when Aircraft is in FLIGHT mode. When aircraft is ready for flight, Battery switch is in 'ON' position there by energizing this Relay-1 to cut off the power supply to Refueling circuit through Battery. In this mode Aircraft power supply is made available to GRP. Circuit breaker is provided to protect the circuit from over load current of battery.

This scheme ensures that refueling operation through battery is done only on Ground. It is ensured that when A/C is in Flight, battery supply is cut off. Data acquisition and Health monitoring unit withdraws power supply to Refueling relay. Also, Relay-1 gets energized during Flight mode. This ensures battery supply is cutoff for refueling operation during flight.

12. Drawings & worked examples
Schematic of Electrically Controlled Pressure Refueling on ground.

Claims

1. This invention addresses the draw backs in using the GROUND POWER RECEPTACLE for the pressure refueling process on ground.

2. This scheme facilitates Refueling process without power interruption using the Internal battery in all emergency condition and in any remote location.

3. Less number of personnel required for this scheme.