Synchronous Generator Exciter Controller for Motor Synchronization

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Solution Overview

Problem

Synchronous generators face challenges in efficiently synchronizing with load-driving motors without increasing mass or decreasing efficiency, as they typically require power electronics, pony motors, and induction rotor devices to achieve alignment, which add complexity and losses.

Innovation Solution

A controller is used to synchronize a synchronous 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 power electronics, pony motors, and induction rotor devices are used to synchronize the generator with 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 power electronics, pony motors, and induction rotor devices from the system, retaining only the essential exciter and controller components needed for synchronization. This extraction eliminates unnecessary mass while preserving the core synchronization function through direct control of field current and prime mover speed.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The exciter and controller serve multiple functions: they control field current for magnetic alignment, regulate prime mover speed for synchronization, and enable the generator to both synchronize with and power the motor load. This multi-functionality replaces the need for separate dedicated synchronization devices.

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

2Adaptability or versatility

If power electronics, pony motors, and induction rotor devices are used to synchronize the generator with motors, then synchronization capability is improved, but energy losses increase

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

Solution Approach 1:

By removing power electronics and induction rotor devices, the patent eliminates the energy losses associated with power conversion, additional magnetic fields, and mechanical friction from these auxiliary components. The system achieves synchronization through direct electromagnetic control, which is inherently more efficient.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The generator's exciter and controller use the generator's own field system to achieve synchronization, rather than requiring external power sources or conversion devices. The field current control directly creates the necessary magnetic alignment without energy-intensive intermediate steps.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If power electronics and induction rotor devices are added to enable line start capability, then adaptability to fixed speed grids is improved, but device complexity increases

Engineering Contradiction:
Improveline start capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent removes power electronics and complex control systems typically required for line start capability, retaining only the exciter and prime mover speed control. This simplified approach achieves synchronization through direct electromagnetic field control rather than complex power conversion and switching circuits.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical synchronization methods (pony motors, induction rotors) with electromagnetic field control through the exciter. The controller adjusts field current to create the necessary magnetic alignment, substituting mechanical complexity with controlled electromagnetic interaction.

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 approach enables efficient synchronization of generators with motors without the inefficiencies and added mass associated with traditional methods, maintaining system efficiency and reducing complexity.

Implementation Method 1

A controller is used to synchronize a synchronous generator with load-driving motors by carefully controlling the field current of an exciter

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

controlling... the rotational acceleration or speed of the prime mover shaft

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP3240183B1Synchronous electrical power distribution system
Publication Date: 2022.05.18 ROLLS ROYCE NORTH AMERICAN TECHNOLOGIES INC
  • EP3240183B1 patent drawingFigure 1
  • EP3240183B1 patent drawingFigure 2
  • EP3240183B1 patent drawingFigure 3

AI summary

A system includes one or more synchronous generators and one or more corresponding exciters. The exciter is configured to output a field current for exciting the synchronous generator to produce a voltage and a current at an output of the synchronous generator. The system may also include one or more electric motors electrically coupled to the synchronous generator and configured to drive one or more mechanical loads. A controller included in the system is configured to identify power angle oscillations between the voltage and the current and control an exciter voltage of the exciter to damp the identified power angle oscillations.