Rotating Electric Machine Control System Multiplex Line Reduction
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Solution Overview
Problem
The existing rotating electric machine control systems for vehicles face challenges in reducing the number of communication lines between the power control unit and the controller without compromising the controllability of the voltage converter, due to increased manufacturing costs and the need to pass communication lines through small openings in the vehicle compartment and engine room.
Innovation Solution
The system incorporates a time corrector to synchronize the timing of detection values from current and voltage detectors with the rotation detector, using a multiplex communication line to transmit communication frames containing multiple detected values, thereby reducing the number of communication lines and maintaining controllability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple separate communication lines are used to transmit detection values from current detector, voltage detector, and rotation detector to the controller, then the controllability and responsiveness of the voltage converter is improved, but the manufacturing cost increases and the installation complexity increases due to needing to pass through small openings in the vehicle compartment and engine room
Solution Approach 1:
The patent combines multiple separate communication lines into a single multiplex communication line that transmits communication frames containing multiple detection values (current, voltage, and rotation position) simultaneously. This merging reduces the number of physical lines needed while maintaining all necessary data transmission functions for controlling the voltage converter.
Solution Approach 2:
The multiplex communication line serves multiple functions by transmitting different types of detection values (current, voltage, rotation position) through a single channel. The communication frame structure allows one line to perform the work of multiple dedicated lines, reducing installation complexity while maintaining full controllability.
2Device complexity
If a multiplex communication line is used to reduce the number of communication lines, then the manufacturing cost is reduced and installation is simplified, but the detection values may not be transmitted simultaneously, potentially deteriorating the controllability of the voltage converter
Solution Approach 1:
The system collects all necessary detection values (current, voltage, rotation position) within the same control cycle before generating the communication frame. This preliminary collection ensures that all data represents the same temporal state, maintaining synchronization without requiring separate transmission lines.
Solution Approach 2:
The controller uses the received detection values to generate control signals for the voltage converter, which are then transmitted back through the same multiplex communication line. This feedback loop ensures that the system maintains proper timing and synchronization by continuously adjusting control based on the most recent synchronized detection data.
Data Source
AI summary
A rotating electric machine control system having a power control unit equipped with a voltage converter and a controller. The controller is equipped with an operation unit having a time corrector for obtaining time from first and second timers with reference to an ignition signal and correcting a relative time difference between the timers. The operation unit obtains electric angles at a preset cycle after correcting time. A communicator obtains electric currents and voltages when obtaining the electric angles for generating a communication frame, and outputs the communication frame to the operation unit via the multiplex communication line. The operation unit simultaneously performs an operation for controlling an inverter and a booster converter based on the obtained electric currents, the voltages, and the electric angles, for reducing the number of communication lines between the power control unit and the controller without compromising controllability of the voltage converter.