EV Powertrain Coil Reconfiguration for Wide Torque-Speed Range
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Solution Overview
Problem
Electric vehicle powertrains face inefficiencies due to large gaps between peak performance specifications and typical use cases, leading to significant system inefficiencies, particularly in heavy-duty trucking and high-performance applications, with losses in electric machines, inverters, and gearboxes contributing to reduced efficiency and increased cost and complexity.
Innovation Solution
The integration of a coil driver system and a power source control system, which allows for dynamic configuration of electric machine coils and voltage management, enabling two torque profiles and bidirectional power flow, thereby optimizing efficiency and reducing the need for dedicated power converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-speed gearboxes are added to meet demanding torque and speed specifications, then the vehicle can achieve peak performance requirements, but system complexity and cost increase significantly
Solution Approach 1:
The patent applies dynamics by making the electrical machine's magnetic circuit configuration changeable during operation. The stator windings can be reconfigured between series and parallel connections, and the magnetic circuit can be dynamically adjusted to have different numbers of parallel paths (1, 2, or 4). This dynamic reconfiguration allows the machine to adapt its torque-speed characteristics without mechanical gearboxes, resolving the contradiction between performance adaptability and system complexity.
2Force
If electric machine size is increased to meet peak torque specifications, then maximum torque requirement is satisfied, but efficiency during typical use cases deteriorates due to large gaps between peak and normal operating conditions
Solution Approach 1:
The patent uses dynamic reconfiguration of the magnetic circuit and winding connections to match the electric machine's operating characteristics to the actual load requirements in real-time. During typical use cases, the machine operates in high-efficiency regions with appropriate magnetic flux levels, while still maintaining the capability to deliver peak torque when needed. This eliminates the need to continuously operate a large machine at low load, reducing energy losses.
Solution Approach 2:
The patent changes key parameters of the electric machine operation including winding connection configuration (series/parallel), magnetic circuit flux levels, and current distribution. These parameter changes allow the machine to optimize its efficiency map across different operating conditions, maintaining high efficiency during typical use while preserving peak torque capability when required.
3Ease of operation
If DC-DC converters are added to manage voltage between battery and electric machine, then voltage management is improved, but system cost and complexity increase
Solution Approach 1:
The patent makes the inverter perform multiple functions: it not only converts electrical power to drive the electric machine but also manages voltage between the battery and machine, replacing the need for separate DC-DC converters. The inverter's switching circuitry is used to reconfigure the stator windings and manage magnetic circuit flux, achieving voltage management as a byproduct of its primary function. This multi-functionality reduces system complexity and cost while maintaining ease of voltage management.
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 enhances efficiency and power output at high speeds without sacrificing low-speed torque, reduces inverter switching losses, and eliminates the need for DC-DC converters, resulting in improved system efficiency and cost-effectiveness.
Implementation Method 1
a coil driver system operable to perform coil configuration of a motor drive system
Data Source
AI summary
An electric vehicle power train can advantageously combine two core technologies, a coil driver system and a power source (e.g., battery) control system (e.g., BCS) to demonstrate several system-level benefits. An electric vehicle power train can advantageously combine two core technologies, a coil driver system and a power source (e.g., fuel cell) control system to demonstrate several system-level benefits. An electric vehicle power train can advantageously include a battery and a BCS along with a fuel cell system. An electric vehicle power train can advantageously include a battery and a BCS without a fuel cell system. An electric vehicle power train can advantageously include a fuel cell system without a battery or a BCS. The coil driver system can implement, for example, two torque profiles within one electric machine by switching stator packs between a series arrangement of coils or windings and a parallel arrangement of coils.