Wind Farm Voltage Regulation via Segmented Local Control

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Solution Overview

Problem

Existing wind farm control systems lack flexibility and rapid intervention capabilities, especially when wind turbines are spatially far apart, making it difficult to effectively regulate network voltage and reactive power.

Innovation Solution

A wind farm control system with a central control unit that determines additive correction values for local setpoints of wind turbines, using two parallel controllers to adjust voltage, power factor, or reactive power, allowing for rapid regulation without the need for fast data transmission media, even across distant turbines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a centralized control system with slow controllers is used at farm level, then coordination between distant wind turbines is achieved, but the response time for voltage regulation becomes too slow to meet grid requirements

Engineering Contradiction:
Improvecoordination between distant turbinesVSAvoidresponse time for voltage regulation
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The control system is segmented into two independent parallel controllers: a first controller that processes slow coordination signals from the farm level, and a second controller that executes fast local voltage regulation. This segmentation allows each controller to operate at its optimal speed without compromising the other, resolving the contradiction between coordination reliability and response speed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adapts the control response time based on the specific regulation task. The first controller handles slow-varying coordination requirements, while the second controller provides fast dynamic response for immediate voltage regulation needs. This dynamic multi-rate control structure enables the system to meet both slow coordination and fast response requirements simultaneously.

Inventive Principle:
Principle #15Dynamics

2Speed

If fast data transmission media are used to enable rapid control intervention, then response time improves, but system complexity and cost increase

Engineering Contradiction:
Improvecontroller intervention speedVSAvoiddata transmission infrastructure
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The fast control functionality is extracted from the centralized farm-level controller and implemented as a separate local second controller at each wind turbine. This extraction eliminates the need for fast data transmission infrastructure between the farm master and individual turbines, as the fast control decisions are made locally without requiring rapid communication with the central system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Each wind turbine is equipped with a local second controller that autonomously performs fast voltage regulation without requiring real-time communication with the farm-level controller. The local controller uses measurements from its own voltage sensor and applies control actions independently, enabling self-service fast control that avoids complex data transmission requirements.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a single centralized controller specifies target values for all wind turbines, then control simplicity is maintained, but flexibility in adapting to local conditions is reduced

Engineering Contradiction:
Improvecontroller structureVSAvoidadaptation to local conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The centralized target value specification is segmented into two components: the first controller provides slow-varying coordination targets, while the second controller independently determines fast local control actions based on real-time local measurements. This segmentation enables each controller to adapt to local conditions within its respective time scale, combining structural simplicity with operational flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second controller at each wind turbine implements local quality control by using local voltage measurements and applying locally-adapted control strategies. Each turbine's second controller can independently adjust its control parameters based on its specific electrical connection characteristics and local grid conditions, providing flexibility without increasing overall system complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2244348B8Wind farm with multiple wind energy assemblies and method for regulating the feed-in from a wind farm
Publication Date: 2019.03.06 NORDEX ENERGY

AI summary

A wind farm comprises a turbine control (32) for at least one wind turbine which determines a local desired value (54) for an electric variable to be generated by the wind turbine by way of a second regulator, depending on an actual value of an electric variable measured in the farm grid. The turbine control determines the sum of the local desired value and correction value (36) as the total desired value (60) for the electric variable of wind turbine to be generated. An independent claim is also included for the method for regulating electric variable fed into electricity supply main by wind farm.