Single-Phase to Three-Phase AC Voltage Switch for Motor Inverters

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Solution Overview

Problem

Existing frequency converters for motors are difficult to control and regulate efficiently, particularly when converting single-phase AC voltage to three-phase AC voltage.

Innovation Solution

A switch with a specific configuration that allows easy conversion from single-phase to three-phase AC voltage without additional control signals, integrated with a frequency converter to generate three-phase AC voltage from single-phase AC voltage, and a motor system that determines rotation direction based on input configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a frequency converter converts single-phase AC voltage to three-phase AC voltage, then the motor can operate with three-phase power, but the control and regulation becomes difficult and complex

Engineering Contradiction:
Improveconversion capability from single-phase to three-phaseVSAvoidcontrol complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The frequency converter automatically detects the input phase configuration (single-phase or three-phase) and self-adjusts the switching element connections without requiring external control signals or manual configuration. The system serves itself by autonomously determining the appropriate switching pattern based on the detected input conditions, eliminating the need for complex external control circuitry.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical control mechanisms with an electronic detection and automatic switching system. Instead of using manual switches or complex control relays to configure the switching elements, the system uses electronic phase detection and automatic electronic switching controlled by a microprocessor or logic circuit that responds to the detected input configuration.

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

2Manufacturing precision

If additional control signals are used to control the frequency converter, then the switching precision improves, but the device complexity and control difficulty increases

Engineering Contradiction:
Improveswitching precisionVSAvoidcontrol signal requirements
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The frequency converter autonomously determines the appropriate switching pattern by detecting the input phase configuration and automatically configuring the switching elements without requiring external control signals. The system self-regulates the switching precision based on the detected input conditions, eliminating the need for additional control wiring and signals.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system incorporates phase detection circuitry that continuously monitors the input voltage configuration and provides feedback to the control logic. This feedback mechanism enables the system to automatically adjust the switching element connections based on the detected single-phase or three-phase input, ensuring precise switching without requiring external control signals.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the switch configuration is simplified, then the ease of operation improves, but the ability to determine rotation direction may be compromised

Engineering Contradiction:
Improveswitching simplicityVSAvoidrotation direction control
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The frequency converter automatically detects the desired rotation direction and self-configures the switching element connections accordingly without requiring manual switching operations. The system monitors the motor load and input configuration, then autonomously establishes the appropriate phase sequence to achieve the desired rotation direction.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The switching configuration is made dynamic rather than static. The system can change the switching pattern in real-time based on the detected input configuration and desired operation mode, allowing the same physical switch position to result in different phase connections depending on the input phase sequence, thereby enabling rotation direction control without additional mechanical switches.

Inventive Principle:
Principle #15Dynamics

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

Facilitates easy and efficient control of frequency converters, enabling seamless conversion and direction change of motors without additional control signals, enhancing operational flexibility and efficiency.

Implementation Method 1

the frequency converter is configured to generate a three-phase alternating voltage from a single-phase alternating voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3457561B1Motor with a frequency inverter and a switch for switching a single-phase alternating current
Publication Date: 2025.10.29 LOCK ANTRIEBSTECHN
  • EP3457561B1 patent drawingFigure 1~2
  • EP3457561B1 patent drawingFigure 3~5

AI summary

Switch for switching a single-phase alternating voltage, wherein the switch comprises an input interface having two input channels, wherein the switch comprises an output interface having three output channels, and wherein the switch has a switching element with a switching contact such that, by switching the switching element, the switching contact closes an electrically conductive contact between a first input channel and a first output channel or between the first input channel and a second output channel.