Power Conditioning Islanding Detection via Reactive Power Injection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Distributed power systems face challenges in detecting islanding conditions, which can lead to grid failures and operator safety risks due to the inability to accurately identify when a distributed power generator continues supplying power without an external grid connection.

Innovation Solution

A power conditioning system that utilizes a processor to identify grid frequency variations and measured frequencies through reactive power injection, detecting islanding based on the number of times these exceed critical ranges within a predefined period, leveraging low-order harmonic variations for enhanced reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional frequency-based islanding detection is used, then the system can detect islanding conditions, but false detection occurs during normal grid operation and detection reliability is insufficient

Engineering Contradiction:

Improveislanding detection reliabilityVSAvoiddetection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent dynamically adjusts the reactive power injection amount based on detected frequency deviations. When frequency deviation exceeds a threshold, the system increases reactive power injection to amplify the effect, enabling more reliable islanding detection while adapting to changing grid conditions to reduce false positives

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the injection amount parameter of reactive power based on the detected frequency state. By varying the reactive power injection level according to frequency deviations, the system enhances detection sensitivity during islanding while maintaining normal operation during grid-connected mode, thereby improving both reliability and measurement precision

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If reactive power injection is increased to improve detection sensitivity, then islanding can be detected with finer grid status changes, but false detection possibility increases during normal operation

Engineering Contradiction:

Improvedetection sensitivityVSAvoidfalse detection rate

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system dynamically adjusts the reactive power injection amount based on detected frequency deviations. When frequency deviation exceeds a threshold, the system increases reactive power injection to amplify the effect, enabling more reliable islanding detection while adapting to changing grid conditions to reduce false positives

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250271475A1Method for detecting whether there is islanding and power conditioning system using same

Publication Date: 2025.08.28 HANWHA SOLUTIONS CORP

AI summary

A power conditioning system according to an aspect includes a processor that is configured to identify a first grid frequency variation and a measured frequency according to injection of reactive power, identify whether at least one of the first grid frequency variation or the measured frequency exceeds a critical range, and detect an islanding based on the number of times of exceeding the critical range within a predefined period of time.