Converter Circuit Voltage Dip Simulation for Grid Testing

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Solution Overview

Problem

Existing methods for testing energy generators and consumers, such as wind turbines, can only simulate voltage dips in fixed steps and frequencies, failing to accurately mimic real-world short circuits, which limits the effectiveness of fault-ride-through condition testing.

Innovation Solution

An electrical circuit with a converter circuit and switch configuration, including a choke coil and electronic power semiconductor switches, allows for dynamic control of voltage at a connection point, enabling simulation of any desired voltage curves and frequencies, thereby simplifying and improving the testing of energy generators and consumers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If fixed-step voltage dip simulation is used, then the testing procedure is simplified, but the simulation accuracy and realism are reduced

Engineering Contradiction:
Improvetesting procedure simplicityVSAvoidvoltage dip simulation accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from fixed-step voltage dip simulation to continuous, dynamically adjustable voltage curves. The converter circuit is controlled to generate voltage dips with variable depth, duration, and shape, allowing realistic simulation of actual grid faults while maintaining testability through systematic control parameters.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention utilizes parameter changes by enabling continuous adjustment of voltage dip characteristics including depth, duration, and waveform shape. The converter circuit responds to control signals that modify these parameters in real-time, allowing comprehensive testing of generator fault-ride-through capabilities under diverse voltage dip conditions.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If converter circuit alone is used for voltage control, then voltage adjustment is achieved, but the transition characteristics and network hardness cannot be adequately controlled

Engineering Contradiction:
Improvevoltage adjustment capabilityVSAvoidtransition characteristic control
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the voltage control function into two distinct components: the converter circuit for voltage magnitude adjustment and the series choke coil for transition characteristic control. This segmentation allows independent optimization of each function, with the choke coil specifically addressing network hardness and transition dynamics that the converter alone cannot achieve.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The series choke coil acts as an intermediary element between the converter circuit and the generator. It mediates the voltage transition by introducing inductive reactance that shapes the voltage dip profile, controlling the rate of change and providing realistic network impedance characteristics during fault simulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If overload capacity is increased to handle short circuit simulation, then the simulation capability is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveshort circuit simulation capabilityVSAvoidconverter overload capacity requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The series choke coil serves as a mediator that enables short circuit simulation without requiring the converter circuit to handle full short circuit currents. The choke coil limits the current magnitude while maintaining the voltage dip characteristics, allowing realistic short circuit testing with reduced stress on the converter components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This solution enables realistic simulation of short circuits and voltage dips at various frequencies, allowing for more comprehensive testing of energy generators' fault-ride-through capabilities with reduced overload capacity and increased precision.

Implementation Method 1

a converter circuit (29) is present, with which a voltage present at the connection point (P) can be influenced

Methodology Applied
Scientific EffectElectrical Energy Conversion:

Implementation Method 2

there is a series circuit that is made up of a choke coil (31) and a first switch (32) and that is coupled to the connection point (P)

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP2244373B1Method and electric circuit for testing an energy generator or energy consumer which can be connected to an electrical energy supply network
Publication Date: 2014.06.11 GE ENERGY POWER CONVERSION GMBH
  • EP2244373B1 patent drawingFigure 1
  • EP2244373B1 patent drawingFigure 2

AI summary

The method involves influencing voltage (Vpcc) using a converter circuit (29), where the voltage like at a connection point (P) to which an energy generator or an energy consumer is attached. A series connection is designed from an induction coil (31) and a switch (32). The series connection is coupled with the connection point. The converter circuit is influenced such that the voltage is transferred to the connection point in a desired value and the switch is closed. A parallel circuit is designed from an induction coil and another switch. An independent claim is also included for an electrical circuit for testing an energy generator, comprising an induction coil.