Controller Distributing Current by Temperature to Prevent Overheating

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Solution Overview

Problem

Conventional electric power steering devices with multiple winding wire and inverter systems experience uneven heat generation, leading to potential overheating issues without adequate consideration or mitigation.

Innovation Solution

A controller for a rotating electric machine that includes an instruction calculator, temperature calculator, distributor, and electric current control section, which calculates and distributes instruction values based on system temperatures to manage electric current flow and prevent overheating by adjusting torque instruction values for each winding wire group.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple winding wire groups and inverters are used to increase power output, then the power capability is improved, but uneven heat generation occurs causing overheating risks

Engineering Contradiction:

Improvepower outputVSAvoidheat generation uniformity

Core Design Contradiction:

PowerVSTemperature

Solution Approach 1:

The controller measures the temperature of each system and uses this feedback to dynamically adjust the instruction value distribution. The temperature measurement unit continuously monitors thermal states, and the controller modifies current distribution based on these measurements, creating a closed-loop control system that prevents overheating while maintaining high power output capability

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The instruction value distribution is made dynamic rather than static. The controller continuously adjusts the proportion of instruction values allocated to each system based on real-time temperature conditions. When one system becomes hotter, its share of the instruction value decreases, allowing the cooler system to承担 more load, creating a dynamic load-balancing mechanism

Inventive Principle:

Principle #15Dynamics

2Device complexity

If equal instruction values are distributed to all winding wire groups, then the control simplicity is maintained, but overheating occurs due to uneven heat generation

Engineering Contradiction:

Improvecontrol simplicityVSAvoidoverheat prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Each system receives a customized instruction value proportion tailored to its local thermal conditions rather than a uniform distribution. The controller applies different control parameters to different systems based on their individual temperature states, allowing precise local optimization of heat management while maintaining overall system coordination

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The controller changes the operational parameters (instruction value proportions) based on temperature conditions. By dynamically adjusting these parameters according to measured temperatures, the system adapts its control strategy to prevent overheating without requiring complex structural modifications

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9692343B2Controller calculating a distribution value to control electric current flow

Publication Date: 2017.06.27 DENSO CORP

AI summary

A controller controls a rotating electric machine that has a plurality of winding wire groups, by using an instruction calculator, a temperature calculator, a distributor, and an electric current control section. The instruction calculator calculates an assist instruction value regarding a drive of the machine. The machine has systems each having a combination of a winding wire group and an inverter. The distributor distributes the assist instruction value among the winding wire groups according to system temperatures, for the calculation of torque instruction values for the respective winding wire groups. In such manner, an overheat of the machine and the inverters is prevented.