Synchronous Generator Self-Synchronization Control

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Solution Overview

Problem

Synchronous power systems face challenges in efficiently synchronizing generators with load-driving motors without increasing mass or decreasing efficiency, often requiring power electronics, pony motors, and induction rotor devices.

Innovation Solution

A controller is used to synchronize a generator with load-driving motors by carefully controlling the field current of an exciter and the rotational acceleration or speed of the prime mover shaft, eliminating the need for additional power electronics and induction rotor devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional methods (power electronics, pony motors, induction rotor devices) are used to synchronize generator with load-driving motors, then synchronization capability is improved, but system mass increases and efficiency decreases

Engineering Contradiction:
Improvesynchronization capabilityVSAvoidsystem mass
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent removes the need for external synchronization devices (power electronics, pony motors, induction rotor devices) by extracting the synchronization capability directly into the synchronous machine itself. The machine can synchronize with the electrical grid without requiring these additional components, thereby reducing system mass while maintaining synchronization capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The synchronous machine performs self-synchronization by utilizing its own electromagnetic characteristics and control systems. The controller manages the field current and rotational speed to achieve synchronization autonomously, eliminating the need for separate pony motors or induction rotor devices, thus reducing overall system mass.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If traditional methods (power electronics, pony motors, induction rotor devices) are used to synchronize generator with load-driving motors, then synchronization capability is improved, but energy efficiency decreases

Engineering Contradiction:
Improvesynchronization capabilityVSAvoidsystem efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent eliminates energy-wasting components by extracting synchronization capability into the synchronous machine itself. Power electronics converters, pony motors, and induction rotor devices are removed, preventing their associated energy losses from affecting system efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The synchronous machine achieves self-synchronization through controlled field current and rotational speed management, eliminating the need for external energy-consuming devices. This self-service approach reduces energy losses by avoiding the inefficiencies of power electronics conversion and auxiliary motor operations.

Inventive Principle:
Principle #25Self-service

3Loss of energy

If synchronous machines are used to drive mechanical loads from fixed speed national electrical grids, then efficiency is improved, but line start capability is lost

Engineering Contradiction:
Improveoperating efficiencyVSAvoidline start capability
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic control of the synchronous machine during startup. The controller adjusts field current and rotational speed in real-time to enable the machine to start from a stationary position on the electrical grid, then transition to efficient synchronous operation. This dynamic approach combines the line-start capability with maintained operating efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes operational parameters (field current magnitude, rotational speed, excitation level) during the startup sequence to enable line-start capability. By dynamically adjusting these parameters, the synchronous machine can accelerate from standstill while connected to the grid, then settle into efficient synchronous operation, combining adaptability with energy efficiency.

Inventive Principle:
Principle #35Parameter changes

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 approach enables efficient generator-to-load motor synchronization without the inefficiencies and mass increases associated with traditional methods, ensuring stable and efficient power delivery.

Implementation Method 1

a exciter operatively coupled to the generator and configured to generate a magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a generator mechanically coupled to the prime mover and electrically coupled to the one or more electrical motors... the generator and the one or more electrical motors are synchronized to one another

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3197043B1Multiple generator synchronous electrical power distribution system
Publication Date: 2022.11.02 ROLLS ROYCE NORTH AMERICAN TECHNOLOGIES INC
  • EP3197043B1 patent drawingFigure 1
  • EP3197043B1 patent drawingFigure 2
  • EP3197043B1 patent drawingFigure 3

AI summary

A power system includes a bus, a first controller and one or more second controllers. The first controller is configured to excite a first generator to generate electric power on the bus in response to initiation of rotation of the first generator. The one or more second controllers are configured to excite one or more respective second generators with a constant excitation in response to initiation of rotation of the first generator. The second generator(s) are electrically coupled with the bus and configured to operate as a motor to commence synchronous rotation with the first generator in response to electric power being present on the bus. The second controller(s) are further configured to initiate dynamic adjustment of the excitation of the second generator(s) to generate electric power on the bus with the second generator(s) in response to the first generator and the second generator(s) synchronously reaching a predetermined rotational speed.