Parallel Matrix Converter Reactor Merging

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Solution Overview

Problem

The existing parallel multiplex matrix converter configurations require reactors on both input and output sides, leading to a large apparatus size and high surge voltage issues when bidirectional switches are turned off.

Innovation Solution

The solution involves directly coupling the output phases of matrix converters in parallel without output reactors and placing first reactors between the AC power supply and input phases, allowing input reactors to function as both filter and output reactors, thereby miniaturizing the apparatus and reducing surge voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reactors are inserted on both input and output sides of parallel multiplex matrix converters, then short-circuit prevention and current balance equalization are achieved, but the apparatus size becomes large

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidapparatus size

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the input reactor and output reactor into a single reactor by utilizing the input reactor as both the input filter reactor and the output reactor for parallel coupling. This is achieved by configuring the input reactor with sufficient inductance to serve dual purposes: filtering input current and preventing short-circuits between parallel converters, thereby eliminating the need for separate output reactors and reducing overall apparatus size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The input reactor is designed to perform multiple functions simultaneously: it acts as an input filter reactor for PWM current smoothing, serves as an output reactor for preventing short-circuits between parallel matrix converters, and provides current balance equalization. This multi-functionality approach allows a single reactor to replace what would traditionally require two separate reactors.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If reactors are inserted on output sides of matrix converters, then short-circuit prevention is achieved, but surge voltage becomes large at the time of turning bidirectional switches off

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidsurge voltage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By merging the input reactor and output reactor into a single reactor configuration, the patent eliminates the separate output reactor that would generate surge voltage when bidirectional switches are turned off. The input reactor, designed with sufficient inductance, provides the necessary short-circuit prevention functionality without creating harmful surge voltages during switch turn-off.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If output reactors are inserted in parallel multiplex matrix converters, then current balance equalization is achieved, but the apparatus configuration becomes large

Engineering Contradiction:

Improvecurrent balance equalizationVSAvoidapparatus configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the current balance equalization function with the input reactor by designing the input reactor with sufficient inductance to serve as both the input filter and the current balance equalizing element. This eliminates the need for separate output reactors and simplifies the overall apparatus configuration while maintaining current balance equalization among parallel matrix converters.

Inventive Principle:

Principle #5Merging (Combining)

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 configuration minimizes the overall size of the apparatus and effectively prevents short-circuits and current imbalances while suppressing surge voltage during bidirectional switch turn-off.

Implementation Method 1

first reactors are provided so as to be inserted respectively between the AC power supply and the input phases from the AC power supply

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

reactors coupled on the output sides in the related art are moved to the positions on the input sides

Methodology Applied

Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentUS7626840B2Parallel multiplex matrix converter

Publication Date: 2009.12.01 YASKAWA DENKI KK

AI summary

The parallel multiplex matrix converter couples in parallel at least two matrix converters, each of which PWM-controls bidirectional switches coupling input phases from an AC power supply to each output phases so as to output an arbitrary AC voltage or DC voltage. The output sides of the matrix converters are directly coupled in parallel to each other without any reactor. The input sides of the matrix converters use reactors inserted between the input phases from the AC power supply and the AC power supply at each of the respective matrix converters coupled in parallel.