Synchronous Machine Rotor Power Storage

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Solution Overview

Problem

Conventional generators face limitations in achieving higher power density and faster dynamic response due to inadequate field coil current control.

Innovation Solution

A synchronous machine with a rotor carrying a field winding and a re-chargeable power storage device, connected via an asymmetric H-bridge rotating power converter, which includes solid-state switches and a capacitor to regulate current flow and reduce ripple, allowing for improved control in charge, generate, and motor modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional field coil current control methods are used, then the generator structure is simple, but power density and dynamic response are limited

Engineering Contradiction:
Improvepower densityVSAvoidcontrol system complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of field coil current through a rotating rectifier assembly with controllable diodes that can be selectively activated or deactivated. This allows real-time adjustment of field current magnitude and direction, enabling rapid dynamic response and enhanced power density while maintaining a relatively simple overall structure. The dynamic switching capability permits the system to adapt field excitation levels to match instantaneous power demands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameters of the field coil by controlling the rectifier output to provide variable current magnitude and polarity. By adjusting the conduction angles and switching states of the rectifier diodes, the system can dynamically alter field current parameters to optimize power density and response characteristics without requiring complex external control systems.

Inventive Principle:
Principle #35Parameter changes

2Speed

If conventional field coil current control is used, then the system is simple, but dynamic response speed is slow

Engineering Contradiction:
Improvedynamic response speedVSAvoidcontrol mechanism complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The rotating rectifier assembly incorporates dynamically controllable diodes that can be rapidly switched on and off based on control signals. This dynamic configuration allows the system to respond quickly to changes in power demand by adjusting field current in real-time, achieving fast dynamic response without introducing complex external control mechanisms. The diode switching occurs within the rotating assembly itself, maintaining simplicity while enhancing speed.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a rotating rectifier is used to convey current to the rotor, then real-time current control is achieved, but power loss and efficiency are reduced

Engineering Contradiction:
Improvereal-time control capabilityVSAvoidpower loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces traditional mechanical commutators and brushes with a solid-state rotating rectifier assembly using diodes and thyristors. This substitution eliminates mechanical contact losses and reduces friction, while maintaining the capability for real-time current control through electronic switching. The solid-state components provide more efficient power conversion with lower losses compared to mechanical systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enhances power density and dynamic response by enabling rapid field current control and efficient energy storage, improving voltage regulation and power management.

Implementation Method 1

The rotor carries a field winding and a re-chargeable power storage device. The re-chargeable power storage device is electrically connected to the field winding to provide electrical power to the field winding

Methodology Applied
Scientific EffectElectrical energy storage: Electrical Accumulator

Implementation Method 2

An inductor can be connected between the re-chargeable energy storage device and the rotating power converter, thereby reducing ripple in current provided to the re-chargeable energy storage device in the charge mode

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

A capacitor is connected in across the rotating power bus and is a part of the rotating power converter

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 4

The rotor carries a field winding... the magnetic field produced by the rotor field coil interacts with the stator armature windings, thereby generating electric current

Methodology Applied
Scientific EffectElectromagnetic field generation: Electromagnet

Implementation Method 5

a rotating rectifier carried by the rotor... conveys current for the field coil from the stator to the rotor during rotor rotation

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3046235B1Synchronous machine with rechargeable power storage devices
Publication Date: 2019.06.05 HAMILTON SUNDSTRAND CORP
  • EP3046235B1 patent drawingFigure 1
  • EP3046235B1 patent drawingFigure 2
  • EP3046235B1 patent drawingFigure 3

AI summary

A rotor portion of a synchronous machine includes a rotor. The rotor carries a field winding 112 and a re-chargeable power storage device 108. The re-chargeable power storage device is electrically connected to the field winding to provide electrical power to the field winding while in generate or motor mode, and to provide electrical power to the re-chargeable power storage device while in a charge mode.