Dual Rotating Machine Drive for EV Torque Transition Smoothing
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Solution Overview
Problem
Existing electric vehicle wheel drive devices experience a significant drop in mechanical torque during transition speeds, leading to discomfort for the driver due to unexpected torque changes.
Innovation Solution
A drive device with two rotating machines, each with distinct predetermined transition speeds, is used to smooth out torque drops by transitioning between different control signals for each machine, ensuring that one machine's torque drop is compensated by the other.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single rotating machine is used with control signal transitions, then the drive device can operate across different speed ranges, but torque drop occurs during transition speeds causing driver discomfort
Solution Approach 1:
The drive device is segmented into two rotating machines (first and second rotating machines) with different transmission ratios and transition speeds. This segmentation allows each machine to handle different speed ranges independently, preventing the torque drop that would occur in a single machine system during control signal transitions.
Solution Approach 2:
The patent merges two rotating machines with distinct transition speeds into a single drive device. The control module coordinates both machines so that when one machine experiences torque drop during transition, the other machine compensates, thereby eliminating the harmful torque drop effect while maintaining versatile speed range coverage.
2Object-generated harmful factors
If two rotating machines with distinct transition speeds are used, then torque drop is smoothed out, but device complexity increases
Solution Approach 1:
Both rotating machines are designed with universal control capabilities, allowing the control module to manage two different machines with distinct transition speeds using a unified control strategy. This multi-functionality enables torque drop compensation without requiring entirely separate control systems, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent changes key parameters of the rotating machines, specifically setting different transmission ratios and distinct transition speeds for the first and second rotating machines. This parameter differentiation allows the system to smooth out torque drops while the control module manages the complexity through coordinated parameter optimization.
3Productivity
If control signals are transitioned for optimal speed control, then operational efficiency is improved, but torque drop occurs at transition speeds
Solution Approach 1:
The control module is configured to anticipate and coordinate control signal transitions between two rotating machines. By planning transitions in advance and having the second machine ready to compensate when the first machine transitions, the system maintains operational efficiency while preventing torque drop, as the compensation is prepared before the harmful effect occurs.
Solution Approach 2:
The patent ensures continuous useful action by having two rotating machines operate in coordination. When one machine transitions control signals and experiences torque drop, the other machine maintains continuous torque output, ensuring that the overall useful action (driving torque) remains continuous and efficient without interruption or significant reduction.
Data Source
Figure 1~2
AI summary
The invention relates to a drive device (2) configured to drive a transmission element (4) comprising: - a first rotating machine (6) connected to the transmission element (4), the first machine (4) having a first transition speed; - a second rotating machine (8) connected to the transmission element (4), the second machine (8) having a second transition speed distinct from the first transition speed; - a control module (10) configured to transmit a command from among a first command and a second command to the first machine (6) and to the second machine (8), the transition from one command to the other command transmitted to the first rotating machine (6) being a function of the first speed and the transition from one command to the other command transmitted to the second rotating machine (8) being a function of the second speed.