Separately Excited Synchronous Machine Emergency Operation
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Solution Overview
Problem
Existing synchronous machines lack robust safety measures to ensure continued operation and efficient torque generation during excitation field failures, which can lead to reduced efficiency and stability.
Innovation Solution
The electric machine is designed with field coils on the rotor, allowing it to operate as a reluctance motor or asynchronous motor when the excitation field is not energized, utilizing existing control electronics and sensors to adapt control methods and generate torque without additional hardware, and incorporating a thermal engine model for temperature simulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the synchronous machine is designed to operate only in synchronous mode with field coils, then high efficiency and high power density are achieved during normal operation, but the machine cannot operate during excitation field failures
Solution Approach 1:
The synchronous machine is designed to perform multiple functions by operating in different modes: synchronous motor mode during normal operation and reluctance motor mode during emergency operation when field coils fail. The rotor design with pronounced poles enables both operating modes without additional hardware, allowing the machine to adapt its function based on operational conditions
Solution Approach 2:
The control method dynamically adapts based on the operational state of the field coils. When field coils are energized, synchronous control is applied; when they fail, the control automatically transitions to reluctance motor control. This dynamic adaptation ensures continuous operation while managing the complexity through software-based control switching
2Reliability
If additional sensors and hardware are added to detect field failure and enable emergency operation, then reliability during field failure is improved, but device complexity and cost increase
Solution Approach 1:
The control electronics utilize existing sensors and measurement capabilities already present in the synchronous machine to detect field failure conditions. The system monitors its own state using available data from current and voltage sensors, eliminating the need for additional dedicated failure detection sensors or hardware
Solution Approach 2:
Existing sensors in the synchronous machine are made multi-functional by using them both for normal operation control and for detecting field failure conditions. The same measurement infrastructure serves dual purposes, reducing hardware requirements while maintaining reliable failure detection
3Productivity
If the machine is designed with high power density and small construction volume, then efficiency is improved, but the machine lacks robustness for emergency operation
Solution Approach 1:
The rotor is designed with pronounced poles that enable the machine to operate in both synchronous mode (for high power density and efficiency) and reluctance motor mode (for emergency operation). This universal design allows the same compact structure to deliver high performance in normal operation while maintaining robustness for emergency conditions without requiring additional hardware
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
Enables safe emergency operation with efficient torque generation and high power density, maintaining efficiency and stability even during excitation field failures by adapting control methods and utilizing existing sensors and hardware.
Implementation Method 1
fields coils arranged on a rotor of the synchronous machine
Implementation Method 2
stator windings for generating a rotary field
Implementation Method 3
a torque can be generated even when the rotor is de-energized
Implementation Method 4
operated as a reluctance motor or asynchronous motor when the field coils are not energized
Data Source
Figure 1
AI summary
The invention relates to a method for operating a separately excited synchronous machine, to an electric machine and to the use thereof, wherein field coils are arranged at the rotor of the synchronous machine, wherein the synchronous machine is operated as a reluctance machine or as an asynchronous machine in case of non-energization of the field coils, in particular in case of emergency operation and/or excitation field failure.