Power Controller Switching Rotation for Heat and Bus Voltage Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional power controllers face issues with heat generation and control delay due to sequential switching of switch elements, hindering miniaturization and weight reduction, and require large capacitors to stabilize bus voltage.

Innovation Solution

A power controller that distributes switching operations evenly across switch elements by rotating the starting point of each switch element's operation, reducing switching frequency and incorporating pulse width correction to stabilize bus voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If switch elements are driven sequentially one by one for each control cycle, then the switching count of individual switch elements is reduced and heat generation is made uniform, but the control delay increases and responsiveness deteriorates

Engineering Contradiction:
Improveheat generation of switch elementsVSAvoidresponsiveness of power controller
Core Design Contradiction:
TemperatureVSSpeed

Solution Approach 1:

The control device determines the on-times of all switch elements in advance for each control cycle based on the shunt rate, rather than determining them sequentially during the cycle. This preliminary determination eliminates the control delay while maintaining uniform heat distribution across switch elements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the on-times of switch elements based on real-time shunt rate requirements while maintaining a fixed deterministic sequence. This allows the control device to adapt to changing power conditions without introducing control delay, as the sequence structure is predetermined but the timing parameters are dynamically calculated.

Inventive Principle:
Principle #15Dynamics

2Speed

If the control cycle is reduced to improve responsiveness, then the responsiveness improves, but the switching count of individual switch elements increases and heat generation increases

Engineering Contradiction:
Improveresponsiveness of power controllerVSAvoidheat generation of switch elements
Core Design Contradiction:
SpeedVSTemperature

Solution Approach 1:

By determining all switch element on-times in advance within each control cycle, the system can use shorter control cycles without increasing individual switch element switching counts. The preliminary determination ensures that each switch element is activated only when necessary, maintaining low heat generation even with frequent control updates.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The deterministic sequence automatically distributes switching operations across multiple switch elements, with each element serving itself based on its position in the sequence. This self-service mechanism ensures uniform heat distribution regardless of the control cycle duration, allowing rapid response without excessive heat generation.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If a larger capacity capacitor is used to stabilize bus voltage, then the bus voltage stability improves, but the device size and weight increase

Engineering Contradiction:
Improvebus voltage stabilityVSAvoidweight of power controller
Core Design Contradiction:
Stability of the object's compositionVSWeight of stationary object

Solution Approach 1:

The control device continuously monitors the bus voltage and adjusts the shunt rate accordingly, creating a feedback control system. This active voltage regulation maintains bus voltage stability without requiring large capacitors, as the system dynamically compensates for voltage fluctuations through precise control of switch element on-times.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the operational parameters (on-times) of switch elements to maintain bus voltage within acceptable ranges. By dynamically adjusting these parameters based on real-time conditions, the system achieves voltage stability without relying on large energy storage capacitors that would increase weight and size.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3920004B1Power controller
Publication Date: 2025.08.27 MITSUBISHI ELECTRIC CORP
  • EP3920004B1 patent drawingFigure 1
  • EP3920004B1 patent drawingFigure 2~3
  • EP3920004B1 patent drawingFigure 4~6

AI summary

An operation processing unit (3A) computes an amount of operation for adjusting electric power supplied to a load (5). A signal generator (4) computes, based on an amount of operation, the number of switch elements to be turned on among switch elements (S1) to (Sn) and a duty ratio to be set for the number of switch elements to be turned on and generates, based on the determined number of switch elements and duty ratio, a signal for driving at least one of the switch elements (S1) to (Sn). The signal generator (4) includes a correction value operation unit that obtains a correction value based on a difference of an on-pulse width between a shunt current flowing through a corresponding one of the switch elements and a shunt drive signal for driving the corresponding one switch element, and a corrector that corrects, based on the correction value, an amount of operation output from the operation processing unit.