Wind Farm Fault Response via Terminal Voltage Detection

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Solution Overview

Problem

Wind turbine generators in a wind farm face challenges in distinguishing between internal and external faults, leading to potential damage when continuing operation, as current can flow into fault points from other generators and the grid, worsening the situation.

Innovation Solution

An operation method that detects terminal voltage falls, initiates provisional control by reducing mechanical input and increasing reactive current output, then adjusts based on fault location, prioritizing grid fault response initially and switching to feeder-side internal fault response once the fault is identified, to suppress fault spread without shutting down generators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wind turbine generator continues to operate when terminal voltage falls, then the FRT requirement is met and grid stability is maintained, but current flows into fault points from other generators and worsens the damage

Engineering Contradiction:

Improvegrid stabilityVSAvoidfault damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamic control by switching between two operational modes based on fault detection: initially maintaining normal operation to support grid stability, then transitioning to reduced output mode when internal faults are detected. This dynamic adjustment allows the system to adapt its response based on the actual fault condition, resolving the contradiction between maintaining grid stability and preventing fault deterioration.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control through continuous monitoring of terminal voltage and fault detection mechanisms. When an internal fault is detected, the system receives feedback information and automatically adjusts its operation by reducing mechanical input and reactive current output. This feedback loop enables the system to respond appropriately to changing conditions, preventing current from flowing into fault points while maintaining grid stability.

Inventive Principle:

Principle #23Feedback

2Object-affected harmful factors

If the wind turbine generator reduces mechanical input and increases reactive current output when terminal voltage falls, then fault spread is suppressed, but the generator operation efficiency decreases

Engineering Contradiction:

Improvefault spreadVSAvoidgenerator efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements preliminary action by having the control unit ready to switch to fault suppression mode upon detecting internal faults. The system pre-establishes the control strategy of reducing mechanical input and reactive current output, so that when faults are detected, the transition to protective operation is immediate and automatic, minimizing both fault spread and efficiency loss.

Inventive Principle:

Principle #10Preliminary action

3Object-affected harmful factors

If the wind turbine generator shuts down when internal fault is detected, then fault spread is prevented, but the wind farm loses generation capacity

Engineering Contradiction:

Improvefault spreadVSAvoidgeneration capacity

Core Design Contradiction:

Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent applies local quality control by implementing selective fault management: when an internal fault is detected in one wind turbine generator, only that specific generator reduces its output, while other generators continue to operate at full capacity. This localized response prevents fault spread to other units while minimizing the impact on overall wind farm generation capacity, resolving the contradiction between preventing fault spread and maintaining production.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP2902621B1Wind farm and operation method for the same

Publication Date: 2016.07.20 MITSUBISHI HEAVY IND LTD

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AI summary

An operation method for a wind farm (1) including wind turbine generators (2, 3), at least one feeder (14, 16) to which at least one of the wind turbine generators (2, 3) is connected, and a substation (30) disposed between the at least one feeder (14, 16) and a grid (50), includes: a terminal voltage detection step of detecting terminal voltage of a generator belonging to each of the wind turbine generators (2, 3); a provisional control step of, when fall of the terminal voltage is detected in the terminal voltage detection step, reducing mechanical input to the generator of each of the wind turbine generators (2, 3) and increasing reactive current outputted from the generator; and a fault spread suppression step of, when it turns out after starting the provisional control step that the fall of the terminal voltage occurs in association with a fault on a feeder side of the wind farm (1) with respect to the substation (30), reducing the reactive current which is increased in the provisional control step so as to suppress spread of the fault inside the wind farm (1).