Electric Motor Control Using Composite Angle for Field Weakening
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Solution Overview
Problem
Existing methods for controlling electric motors in vehicle transmissions, particularly in the field-weakening range, face inefficiencies and require costly phase-current-measuring components, limiting their operational efficiency and adaptability to varying load conditions and supply voltages.
Innovation Solution
A method that generates electric voltages for electric motor phases based on a composite angle formed by adding a pilot-control angle to the rotor position angle, allowing for optimized efficiency and torque management without phase-current-measuring components, using a simple and cost-effective regulator structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If field-oriented regulation with phase-current-measuring components is used to maximize efficiency in the field-weakening range, then efficiency is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the phase-current-measuring components from the field-oriented regulation system. Instead of measuring actual phase currents, the invention uses a simplified regulator structure that determines pilot-control angles based on rotor position and supply voltage, thereby reducing device complexity while maintaining efficiency in the field-weakening range
Solution Approach 2:
The patent replaces expensive phase-current-measuring components with a cost-effective regulator structure that uses readily available sensors (Hall sensors or encoder) to determine rotor position. This substitution significantly reduces component cost and device complexity while achieving the same control objective through alternative calculation methods
2Device complexity
If conventional regulation methods are used in the field-weakening range, then device simplicity is maintained, but efficiency and adaptability to supply voltage fluctuations deteriorate
Solution Approach 1:
The patent introduces feedback mechanisms where the regulator continuously monitors rotor position and supply voltage to dynamically adjust pilot-control angles. This feedback loop enables the system to adapt to supply voltage fluctuations and maintain optimal efficiency in the field-weakening range while keeping the regulator structure relatively simple
Solution Approach 2:
The patent implements dynamic adjustment of pilot-control angles based on real-time operating conditions (rotor position, supply voltage, rotational speed). This dynamic approach allows the regulation system to adapt to varying load conditions and supply voltage fluctuations, maintaining high efficiency without requiring complex hardware
3Use of energy by moving object
If high-resolution angle sensors are used to increase angular resolution for sine commutation, then efficiency and quiet running are improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the need for high-resolution mechanical angle sensors with an electronic calculation approach. By using standard-resolution Hall sensors or encoders combined with mathematical calculations to determine pilot-control angles, the system achieves the same level of precision for sine commutation without requiring expensive high-resolution sensors
Solution Approach 2:
The patent creates a virtual high-resolution angle measurement system through software calculations. Instead of physically measuring the angle with high-resolution sensors, the system calculates effective pilot-control angles based on standard sensor data and rotor position, achieving equivalent precision through computational methods
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
Enables efficient operation across a large rotational speed torque range, maximizes efficiency in the field-weakening range, and provides robustness against supply voltage fluctuations and component tolerance, with reduced computational and resource requirements.
Implementation Method 1
Electromechanically or hydraulically activated vehicle transmissions comprise one or more electric motors for pump drives or direct drives
Implementation Method 2
Hall sensors are provided, for example in the electric motor, for the purpose of determining the rotor position
Data Source
AI summary
In a method for controlling an operation of an electric motor, electric voltages applied to electric phases of the electric motor are generated and output in a modulation in a controlled manner dependent on a rotor position of the electric motor and a target/actual comparison of at least one first variable which characterizes a load on the electric motor or an actual rotational speed of the electric motor. A rotor position angle, which characterizes the rotor position, is complemented with a specified preliminary control angle and another regulated preliminary control angle component upon reaching a field weakening range of the electric motor so as to form a sum angle. The sum angle is used to characterize the rotor position in the modulation upon reaching the field weakening range. The disclosure also relates to a device for controlling an operation of an electric motor.