Electric Motor Control Using Pilot Angle Map
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Solution Overview
Problem
Existing methods for controlling electric motors in vehicle transmissions are costly and computationally intensive, with inefficiencies due to speed- and current-dependent offsets and the need for complex phase current feedback measurements.
Innovation Solution
A method and device that use a pre-control angle map to determine voltages based on actual speed and load variables, allowing for precise synchronization of motor current with the rotor position without costly phase current feedback, enabling efficient operation with reduced computational resources and utilizing reluctance torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If field-oriented regulation with phase current feedback is used to synchronize maximum current with rotor position, then motor efficiency is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the phase current feedback measurement component from the control system. Instead of using complex field-oriented regulation with current sensors, the invention uses a simplified control method that determines voltages based on rotor position and load variables without requiring phase current feedback, thereby reducing device complexity while maintaining efficiency
Solution Approach 2:
The patent uses a pilot control angle map (lookup table) that stores pre-calculated optimal control angles for various operating conditions. This copying approach replaces the need for real-time complex calculations and phase current measurements, allowing the system to achieve optimized efficiency by retrieving pre-determined control parameters based on rotor position and load
2Measurement precision
If high-resolution angle sensors are used to increase angular resolution, then voltage adaptation to rotor position is improved, but device complexity and cost increase
Solution Approach 1:
The patent performs preliminary calculations of optimal control angles and stores them in a pilot control angle map for various rotor positions and load conditions. This pre-computation approach eliminates the need for high-resolution angle sensors during real-time operation, as the system retrieves pre-determined angles from the map based on standard rotor position measurements
Solution Approach 2:
The patent changes the control parameter from requiring high-resolution continuous angle measurements to using standard rotor position measurements combined with a lookup table. The pilot control angle map stores optimized control angles that account for various operating conditions, allowing the system to achieve high effective resolution without expensive sensors
3Loss of energy
If sinusoidal commutation with space vector modulation is implemented, then motor efficiency and smooth operation are improved, but computational effort increases
Solution Approach 1:
The patent pre-calculates and stores optimal control angles for sinusoidal commutation in a pilot control angle map. During operation, the system retrieves these pre-computed angles based on rotor position and load variables, avoiding real-time complex space vector modulation calculations while maintaining the benefits of sinusoidal commutation for motor efficiency and smooth operation
Solution Approach 2:
The patent replaces expensive and computationally intensive real-time space vector modulation with a simpler control approach using a lookup table. The pre-computed pilot control angles provide the necessary control information without requiring continuous complex calculations, effectively using a simple data structure (lookup table) instead of complex real-time computation
4Loss of energy
If field-oriented control with d component control strategy is used, then motor efficiency is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the complex d-component control strategy from the field-oriented control system. Instead of implementing full field-oriented control with its complex coordinate transformations and current regulation, the invention uses a simplified approach that determines voltages directly from rotor position and load variables using a pilot control angle map, eliminating the need for complex control strategies while maintaining efficiency
Solution Approach 2:
The patent uses a pilot control angle map that stores pre-determined optimal control angles for various operating conditions. This copying approach replaces the need for real-time field-oriented control calculations and d-component strategies, allowing the system to achieve optimized efficiency by retrieving pre-calculated control parameters based on rotor position and load
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
This approach simplifies control circuitry, avoids delays, and maximizes efficiency with minimal resources, allowing for high-resolution voltage output and smooth motor operation, even in field weakening regions, without the need for expensive phase current feedback.
Implementation Method 1
electrical voltages present in electrical phases of the electric motor being output in a controlled manner as a function of a rotor position of the electric motor, and the output of the voltages being tracked by the rotor position
Implementation Method 2
with Hall sensors being provided in the electric motor to determine the rotor position
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a method for controlling an operation of an electric motor (1), wherein electrical voltages applied to electrical phases of the electric motor (1) are output in a controlled manner as a function of a rotor position of the electric motor (1) and the output of the voltages follows the rotor position. According to the invention, an advance control angle (φPA) is ascertained from an advance control angle characteristic field (KF) as a function of an actual rotational speed (nist) and at least one further variable (G) designating a load on the electric motor (1), wherein the advance control angle (φPA) and a rotor location angle (φ) designating the rotor position are added up to a sum angle (φ∑) and the voltages are ascertained as a function of the sum angle (φ∑) and output in a controlled manner to the electrical phases of the electric motor (1). The invention further relates to a device for controlling an operation of an electric motor (1).