Excitation Boost System for Synchronous Generator Overload
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Solution Overview
Problem
Synchronous generators lack cost-effective solutions for upgrading to meet enhanced overload and short circuit capabilities without increasing active material costs or complexity, particularly in applications where only a small percentage require such performance.
Innovation Solution
An excitation boost system that selectively applies power from a second source, such as a permanent magnet generator or capacitor, to supplement or replace the main machine's excitation during overload conditions, controlled by an automatic voltage regulator to enhance overload performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary windings are embedded in the stator to meet overload requirements, then overload capability is improved, but manufacturing cost and material usage increase
Solution Approach 1:
The invention applies preliminary action by pre-charging a capacitor during normal operation before the overload event occurs. This stored energy is then discharged during overload conditions to provide the necessary excitation current, eliminating the need for auxiliary windings and reducing active material usage while maintaining reliability.
2Reliability
If compounding transformers are used to enhance overload capability, then generator performance is improved, but device complexity and stock requirements increase
Solution Approach 1:
The invention applies universality by using a single capacitor-based excitation system that can serve multiple functions: providing overload support, maintaining voltage during transient conditions, and working with standard generator configurations. This eliminates the need for multiple transformer variants and reduces device complexity.
3Reliability
If a Permanent Magnet Generator is used to provide isolated excitation power, then short circuit maintenance is improved, but device complexity increases
Solution Approach 1:
The invention extracts the energy storage function from the excitation system by using a separate capacitor charged from the main generator output. This capacitor is then used to provide the necessary excitation current during overload conditions, simplifying the overall system by removing the need for a Permanent Magnet Generator while maintaining short circuit capability.
4Reliability
If excitation boost system is added to upgrade generator performance, then overload performance is improved, but device complexity increases
Solution Approach 1:
The invention applies self-service by using the generator's own output to charge the capacitor through the automatic voltage regulator. The system is self-sufficient, requiring no external power source or complex control mechanisms, thereby improving overload performance while minimizing the increase in device complexity.
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 easy upgrading of synchronous generators to provide enhanced overload performance while minimizing costs and complexity, with improved voltage output during overload conditions without the need for additional exciter machines or transformers.
Implementation Method 1
An excitation boost system that selectively applies power from a second source, such as a permanent magnet generator or capacitor
Implementation Method 2
An excitation boost system that selectively applies power from a second source, such as a permanent magnet generator or capacitor
Data Source
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AI summary
Excitation control circuitry for a synchronous generator is disclosed. The synchronous generator is of a type comprising a main machine (2) and an exciter (6) for exciting the main machine. The excitation control circuitry comprises an automatic voltage regulator (10) for controlling power flow from the main machine to the exciter, and an excitation boost system (14) for selectively supplying power from a second source of electrical power (12) to the exciter (6). This can allow additional excitation to be provided, for example, when the generator is in overload. This arrangement can allow a synchronous generator to be upgraded by adding the excitation boost system to provide enhanced overload performance.