Inverter Current Sensor Phase and Direction Detection

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Solution Overview

Problem

The installation of current sensors in energy storage inverters is often incorrect, leading to operational inefficiencies due to improper phase connections and direction reversals, which are difficult to detect without professional intervention.

Innovation Solution

A method and device for detecting the installation state of current sensors by injecting reactive power into each phase of the inverter, comparing initial and output reactive powers to determine matching sensors, and adjusting phases and directions based on threshold differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If current sensors are installed manually by professional installers according to phase sequence and direction, then installation accuracy is improved, but installation time and complexity increase

Engineering Contradiction:
Improveinstallation accuracyVSAvoidinstallation time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system performs preliminary detection by injecting reactive power into each phase and comparing the detected reactive power with expected values to identify correct current sensor installations before full operation begins. This preliminary action allows automatic verification and correction of sensor installation status.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The inverter automatically detects and identifies the installation status of current sensors without requiring professional installers to manually verify each connection. The system uses its own reactive power output and detection capabilities to self-verify sensor installation correctness, reducing dependency on external expertise.

Inventive Principle:
Principle #25Self-service

2Productivity

If current sensors are installed without professional intervention to reduce installation time, then installation efficiency is improved, but installation accuracy deteriorates

Engineering Contradiction:
Improveinstallation efficiencyVSAvoidinstallation accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system injects reactive power into each phase and detects the resulting reactive power output. By comparing detected values with expected values, the system provides feedback on whether current sensors are correctly installed, allowing automatic identification and correction of installation errors without professional intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes operational parameters by injecting specific reactive power into different phases and monitoring the resulting changes in detected reactive power. These parameter changes enable the system to identify which current sensors are correctly installed based on the relationship between injected and detected power values.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If reactive power injection detection method is implemented, then detection accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The inverter uses its existing reactive power output capability for dual purposes: normal energy storage operation and current sensor installation detection. The same detection circuitry and control system are used for both operational control and installation verification, avoiding the need for separate dedicated detection equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Reactive power serves as an intermediary signal for detection. By injecting reactive power into different phases and measuring the resulting reactive power output, the system indirectly determines current sensor installation status without requiring direct physical inspection or additional sensing hardware.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4624966A1Method and device for detecting installation state of current sensor
Publication Date: 2025.10.01 SOLAR POWER NETWORK TECHNOLOGY (ZHEJIANG) CO LTD
  • EP4624966A1 patent drawingFigure 1
  • EP4624966A1 patent drawingFigure 2
  • EP4624966A1 patent drawing

AI summary

The present invention discloses a method and device for detecting an installation state of a current sensor. The method including: obtaining an initial reactive power of each phase of an inverter and an initial current sensor number for a current sensor installed to the phase; injecting a preset reactive power into each phase of the inverter one by one, and acquiring a first reactive power output from each phase of the inverter; determining one by one a matching current sensor for each reference phase based on a comparison result between a first difference and a first preset threshold and generating a matching current sensor number for each phase; adjusting an installation phase of each current sensor according to the matching current sensor number, injecting the preset reactive power to each phase of the inverter one by one, and acquiring a second reactive power output from each phase; and determining an installation direction of the matching current sensor for each phase based on a comparison result between the second difference and the first preset threshold. The present invention provides an effective method for detecting the installation phase position and installation direction of each current sensor on the inverter, thereby improving the installation efficiency of the inverter product.