Hybrid Motor Control Unit With Load-Switched Drive Circuits

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Solution Overview

Problem

The IGBT components in motor control units of electric vehicles have high energy losses, leading to reduced efficiency and endurance due to excessive energy consumption, especially in light load conditions.

Innovation Solution

Implementing a motor control unit with at least two drive circuits, including a first drive circuit with high current withstand capability and a second drive circuit with low loss, where the second drive circuit operates during light loads and both circuits operate during heavy loads, utilizing the respective advantages to improve efficiency and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If IGBT components are used in the motor control unit, then the motor can be driven with high current withstand capability, but energy loss increases and efficiency decreases

Engineering Contradiction:
Improvecurrent withstand capabilityVSAvoidenergy loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The motor control unit is segmented into multiple independent drive circuits (first drive circuit with IGBT and second drive circuit with MOSFET). Each circuit can operate independently or in parallel, allowing the system to select the most efficient configuration based on load conditions. This segmentation enables the MOSFET-based second drive circuit to handle light loads with lower loss, while the IGBT-based first drive circuit handles heavy loads requiring high current withstand capability.

Inventive Principle:
Principle #1Segmentation

2Productivity

If a single drive circuit is used, then the device complexity is low, but the efficiency under varying load conditions cannot be optimized

Engineering Contradiction:
ImproveefficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The motor control unit implements dynamic operation by enabling the first and second drive circuits to switch between different operating modes: the second drive circuit operates alone during light loads for efficiency, the first drive circuit operates alone during heavy loads for high current capability, or both circuits operate in parallel during medium loads. The control unit dynamically selects the optimal configuration based on real-time load conditions, optimizing efficiency across the entire operating range despite the increased device complexity of having multiple drive circuits.

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

The solution enhances the efficiency of the motor control unit by reducing losses in light loads and ensuring safety in heavy loads, thereby improving the endurance of the electric vehicle's power battery pack.

Implementation Method 1

The first drive circuit is configured to convert direct current from the corresponding power supply into alternating current, and supply the alternating current to a first part of windings of the motor. The second drive circuit is configured to convert direct current from the corresponding power supply into alternating current, and supply the alternating current to a second part of windings of the motor.

Methodology Applied
Scientific EffectElectrical inversion:

Data Source

PatentEP4362320B1Motor control unit and power system
Publication Date: 2025.11.26 HUAWEI TECH CO LTD
  • EP4362320B1 patent drawingFigure 1~2
  • EP4362320B1 patent drawingFigure 3
  • EP4362320B1 patent drawingFigure 4

AI summary

This application discloses a hybrid-power-component motor control unit and a power system, where the motor control unit and the power system are applied to the field of electric vehicle technologies. A type of a power component in a first drive circuit of the motor control unit is different from a type of a power component in a second drive circuit of the motor control unit. A loss of the power component in the first drive circuit is greater than a loss of the power component in the second drive circuit. A current withstand capability of the power component in the first drive circuit is greater than a current withstand capability of the power component in the second drive circuit. The first drive circuit inverts a direct current into an alternating current, and supplies the alternating current to a first part of windings of the motor. The second drive circuit inverts a direct current into an alternating current, and supplies the alternating current to a second part of windings of the motor. When determining that a load of the motor is less than a preset load, the control unit controls the first drive circuit to stop working and controls the second drive circuit to work. When determining that the load of the motor is greater than or equal to the preset load, the control unit controls both the first drive circuit and the second drive circuit to work. According to the motor control unit, efficiency of the motor control unit can be effectively improved.