Helicopter Power Supply Merging APU and Motor Generators

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Solution Overview

Problem

Existing aircraft power supply systems for rotorcraft are inefficient due to the need for multiple components and interfaces, leading to increased mass, size, and cost, particularly when transitioning between different electrical power requirements for the APU starter/generator and motor/generators.

Innovation Solution

A control and power supply system utilizing a connection matrix with selectively actuated contactors and DC/AC converters, allowing for the sharing of electrical resources between the APU starter/generator and motor/generators, reducing the need for multiple power supply devices and interfaces by using a common power electronics system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate power supply devices are used for APU starter/generator and motor/generators, then each system can operate independently, but the number of boxes, harnesses, and interfaces increases, leading to increased mass, size, and cost

Engineering Contradiction:
Improveindependent operation capabilityVSAvoidnumber of boxes, harnesses, and interfaces
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines separate power supply devices into a single shared DC/AC converter that can serve both the APU starter/generator and the motor/generators. The converter is controlled to selectively power different systems based on operational requirements, reducing the overall number of components, harnesses, and interfaces while maintaining independent operation capability when needed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The DC/AC converter is designed as a universal power supply device that can perform multiple functions: powering the APU starter/generator, powering motor/generators, and providing selective operation to either system. This multi-functional design eliminates the need for separate dedicated power supply devices, reducing system complexity while preserving operational independence.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If a common power supply device is used for both APU starter/generator and motor/generators, then the number of components is reduced, but the device must be oversized to handle peak power requirements of both systems simultaneously

Engineering Contradiction:
Improvenumber of boxes, harnesses, and interfacesVSAvoidpower supply capacity
Core Design Contradiction:
Device complexityVSPower

Solution Approach 1:

The patent implements dynamic control of the common DC/AC converter through an electronic control circuit that monitors system requirements and selectively activates power delivery to either the APU starter/generator or motor/generators based on operational mode. This dynamic switching capability allows the converter to be sized for individual system requirements rather than the sum of both systems, avoiding oversizing while maintaining flexibility.

Inventive Principle:
Principle #15Dynamics

3Power

If multiple separate power supply devices are used, then each system has dedicated power capacity, but the total mass, size, and cost of the electrical architecture increases

Engineering Contradiction:
Improvededicated power capacityVSAvoidmass of electrical architecture
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The patent merges multiple separate power supply devices into a single common DC/AC converter, eliminating redundant components and reducing the total mass of the electrical architecture. The converter maintains adequate power capacity by being designed to serve one system at a time based on operational requirements, rather than requiring simultaneous capacity for all systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common DC/AC converter is designed as a universal power supply that can fulfill the power requirements of different systems sequentially. This multi-functional approach allows a single device with moderate power capacity to replace multiple heavier dedicated devices, reducing overall system mass while maintaining the ability to provide sufficient power to any single system when needed.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution reduces the number of boxes, harnesses, and interfaces, resulting in a lighter, smaller, and less costly electrical architecture that efficiently manages power distribution across multiple systems, enabling simultaneous operation and power injection without oversizing the common power supply.

Implementation Method 1

a first DC/AC converter intended to supply selectively, according to the respective positions of contactors of a connection matrix actuated from an electronic control circuit, an alternating electrical energy to said at least one motor/generator

Methodology Applied
Scientific EffectElectrical conversion (DC/AC):

Implementation Method 2

formed either by a rectifying circuit of an alternating voltage delivered via a contactor by a starter/generator of an APU

Methodology Applied
Scientific EffectRectification:

Implementation Method 3

by a DC/DC step-up converter supplied from a battery via a contactor

Methodology Applied
Scientific EffectVoltage conversion (DC/DC):

Implementation Method 4

said step-up DC/DC converter is obtained by connecting a three-phase inductor and a second DC/AC converter in series via at least one contactor

Methodology Applied
Scientific EffectElectrical conversion with inductance:

Data Source

PatentEP2847845B1System for control and power supply of turbomachines of a helicopter
Publication Date: 2018.07.04 SAFRAN ELECTRICAL & POWER
  • EP2847845B1 patent drawingFigure 1

AI summary

System for control and electric power supply of at least one helicopter motor/generator comprising a first DC/AC converter (30) intended to provide selectively, according to the respective positions of contactors (320, 322, 324, 326, 328, 330, 332) of a connection matrix (32) which are actuated from an electronic control circuit (34), an AC power supply to at least one motor/generator, this first DC/AC converter being powered with DC voltage by a voltage supply device delivering a DC voltage Vdc and formed either by a circuit (36) for rectifying an AC voltage delivered via a contactor (22) by a starter/generator (18) of an APU (16) or by a DC/DC voltage boosting converter (38) powered from a battery (20) via a contactor (24), the connection matrix furthermore comprising a contactor (328) for placing the first DC/AC converter in parallel with the second DC/AC converter so as to allow, once one at least of these motors/generators has been started, an injection of additional power from the starter/generator of the APU.