Power Conversion System Timing Controller for Converter Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In power conversion systems using distributed power supplies, overlapping control timings of converters lead to unstable DC bus voltage and increased switching noises, resulting in decreased stability and efficiency.

Innovation Solution

A power conversion system with a timing controller that coordinates the start times of converter controllers and an inverter controller, using a predetermined time cycle and random number generator to ensure each converter starts at a different time, thereby dispersing the timing of pulse driving operations and reducing noise overlap.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If converters are controlled to start at the same time, then power conversion efficiency is improved, but DC bus voltage stability deteriorates and switching noise increases

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidDC bus voltage stability
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent applies periodic action by implementing a time-cycle-based control strategy where converters are operated in alternating periods. The control unit divides the operation into first time cycles where odd-numbered converters operate, and second time cycles where even-numbered converters operate, creating a periodic pattern that prevents simultaneous startup while maintaining efficient power conversion over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent segments the converter group into multiple subsets based on their startup timing. Converters are divided into odd-numbered and even-numbered groups that operate in different time cycles, effectively segmenting the overall power conversion process into separate phases that prevent overlapping switching operations and maintain bus voltage stability.

Inventive Principle:
Principle #1Segmentation

2Loss of energy

If converters are controlled to start at the same time, then power conversion efficiency is improved, but switching noise increases

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidswitching noise
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The control unit implements periodic action by alternating the operation of different converter groups in successive time cycles. During first time cycles, odd-numbered converters are activated while even-numbered converters remain inactive, and during second time cycles, the pattern reverses. This periodic alternation distributes switching noise across different time periods, preventing noise accumulation and overlap while maintaining overall power conversion efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent segments the converter operation into distinct time-based groups, separating the switching operations of odd-numbered and even-numbered converters into different operational phases. This segmentation of switching events in the time domain prevents simultaneous noise generation, thereby reducing the overall switching noise level while preserving power conversion efficiency through coordinated operation of all converters.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3128664B1Power conversion system
Publication Date: 2019.04.24 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3128664B1 patent drawingFigure 1~2
  • EP3128664B1 patent drawingFigure 3~4
  • EP3128664B1 patent drawingFigure 5~6

AI summary

A timing controller (C1) in an inverter, an inverter controller (C30), and a plurality of converter controllers (C21 to C26) are connected via a communication line (L2). The timing controller (C1) is configured to provide timing signals to the respective inverter controller (C30) and converter controllers (C21 to C26) in predetermined time cycles which have been set in advance. The respective timing signals are provided so as to prevent two or more of the inverter (30) and converters (21 to 26) from starting to be driven at the same time.