Paralleled Inverter Control via Shared Communication Network

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Solution Overview

Problem

Conventional paralleled inverter systems face reliability issues and increased costs due to the need for separate hardware interfaces for synchronization signal transmission, which can lead to signal delays and noise interference, as well as synchronization errors related to CPU control periods.

Innovation Solution

A control apparatus using a single master controller to transmit operation information to multiple inverters via a shared communication network, such as CAN, with optical interfaces to minimize hardware requirements and correct output current errors using PI control, thereby reducing circulating currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate hardware interfaces are used for synchronization signal transmission between master and slave controllers, then synchronization can be achieved, but signal delay and noise interference occur

Engineering Contradiction:
Improvesynchronization reliabilityVSAvoidsignal delay and noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the hardware interface (electrical connection) with a wireless communication module to transmit synchronization signals. This substitution eliminates physical contact issues such as signal delay and noise interference while maintaining synchronization functionality between the master controller and slave controllers.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a wireless communication module as an intermediary between the master controller and slave controllers. This intermediary transmits synchronization signals without direct electrical connection, thereby avoiding signal delay and noise problems associated with traditional hardware interfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple separate hardware interfaces are provided for each inverter, then individual control is possible, but device complexity and cost increase

Engineering Contradiction:
Improveindividual control capabilityVSAvoidhardware interface complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the master controller universal by equipping it with multiple wireless communication modules that can simultaneously communicate with multiple slave controllers. This allows one master controller to manage multiple inverters individually without requiring separate hardware interfaces for each connection, thereby reducing overall system complexity.

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

Solution Approach 2:

The patent combines multiple communication functions into a single master controller by integrating multiple wireless communication modules. This merging approach allows individual control of multiple inverters while avoiding the complexity of having separate control units or interfaces for each inverter.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of information

If hardware interface is used for synchronization, then signal transmission is possible, but the system is influenced by surrounding circuit noise

Engineering Contradiction:
Improvesignal transmission accuracyVSAvoidcircuit noise interference
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the electrical hardware interface with a wireless communication module that transmits synchronization signals through electromagnetic waves. This substitution eliminates the problem of circuit noise interference that affects traditional wired connections, as there is no physical electrical path for noise to couple into the signal.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Power

If paralleled inverters are designed to expand capacity, then larger power output is achieved, but voltage and current capacity limits of power elements are encountered

Engineering Contradiction:
Improveinverter capacityVSAvoidvoltage and current capacity
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The patent divides a large capacity inverter system into multiple smaller unit inverters connected in parallel. Each inverter operates within the voltage and current capacity limits of its power elements, while the combined system achieves the desired large power output. The master controller coordinates these segmented units to function as a unified system.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2874302B1Apparatus for controlling paralleled inverter
Publication Date: 2019.02.27 LSIS CO LTD
  • EP2874302B1 patent drawingFigure 1
  • EP2874302B1 patent drawingFigure 2
  • EP2874302B1 patent drawingFigure 3

AI summary

An apparatus for controlling paralleled inverter is disclosed. In the apparatus for controlling paralleled inverter, one synchronization signal is shaped by at least two inverters to respectively transmit a voltage command and an operation command.