Generator Protection Element Using Composite Power Tripping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric generators, inadvertent motoring conditions can occur due to prime mover failures, leading to damage and potential harmful system conditions, as existing detection systems are unreliable and often not implemented, especially in generators with low motoring power, where reverse power flow can be small and difficult to detect.
Innovation Solution
Implementing a system that monitors real and imaginary power outputs of generators using intelligent electronic devices (IEDs) with modified tripping characteristics to reliably detect reverse power conditions, allowing for timely protective actions such as tripping, thereby preventing damage and ensuring system safety and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing detection systems are used to monitor reverse power conditions, then the system structure is simple, but the detection reliability is poor and cannot reliably detect reverse power conditions in generators with low motoring power
Solution Approach 1:
The patent changes the detection parameter from simple reverse power threshold to a composite parameter combining real power (P) and imaginary power (Q) with adjustable weighting. This allows the system to reliably detect reverse power conditions in generators with low motoring power by adjusting the imaginary power weight, resolving the contradiction between detection reliability and system complexity.
2Reliability
If the imaginary power weight is increased to improve detection under high imaginary power flows, then detection reliability improves, but the system becomes more sensitive to measurement errors
Solution Approach 1:
The patent implements dynamic adjustment of the imaginary power weight based on operating conditions. The weight is adjusted according to the ratio of imaginary to real power, allowing the system to maintain high detection reliability under high imaginary power flows while reducing sensitivity to measurement errors when imaginary power is low. This dynamic adaptation resolves the contradiction between detection reliability and measurement precision.
3Adaptability or versatility
If a fixed reverse power threshold is used, then the system is easy to implement, but it cannot adapt to different operating conditions and generator types
Solution Approach 1:
The patent implements preliminary configuration of generator-specific parameters including rated real power, rated imaginary power, and initial imaginary power weight during system setup. These pre-configured parameters enable the system to adapt to different generator types and operating conditions without requiring complex real-time adjustments, resolving the contradiction between adaptability and configuration complexity.
Data Source
AI summary
The present disclosure is applicable to generators with low motoring power. In one embodiment, a generator protection element may include a generator monitoring subsystem configured to measure a real power output and an imaginary power output of a generator. The system may also include an electrical parameter threshold subsystem configured to determine whether the measured real power output and the measured imaginary power output satisfy a tripping characteristic. The tripping characteristic may be defined by a function having a slope with respect to a real power axis and an imaginary power axis. In some embodiments, the function may be a piecewise function that defines a first linear segment having a first slope and a second linear segment having a second slope. The first slope and the second slope may be equal and opposite. A tripping subsystem may issue a trip command based upon satisfaction of the tripping characteristic.