Vehicle Power Inverter Standby Control for Faster Torque Activation
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Solution Overview
Problem
Existing vehicle power inverters in hybrid vehicles continue to draw quiescent electrical current even when not needed, leading to reduced battery range due to constant power consumption, and there is a need for faster transitions between engine and electric machine operation to minimize latency and improve responsiveness.
Innovation Solution
A predictive control system that transitions the power inverter to a standby state when the engine is inactive, using predictive conditions based on accelerator position and vehicle speed to preemptively activate the inverter before engine activation is required, reducing quiescent current draw and enabling faster engine activation using a starter-generator when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DC link voltage ripple is reduced through conventional filtering methods, then power quality improves, but device complexity and cost increase
Solution Approach 1:
The controller predicts future DC link voltage values before they occur by using historical voltage data and predictive algorithms. This preliminary action allows the system to proactively adjust inverter switching strategies to prevent voltage ripple, rather than reactively filtering it after it occurs, thereby reducing the need for complex filtering hardware.
Solution Approach 2:
The patent replaces conventional mechanical/electrical filtering systems with a control-based solution. Instead of using physical filters, capacitors, and inductors to reduce DC link voltage ripple, the system uses predictive control algorithms that process voltage data and adjust switching patterns electronically, substituting complex hardware with software-based control.
2Reliability
If DC link voltage is maintained within narrow specifications, then inverter reliability improves, but control complexity increases
Solution Approach 1:
The controller continuously monitors actual DC link voltage values and compares them with predicted values. This feedback mechanism allows the system to detect deviations and adjust switching strategies in real-time to maintain voltage within specifications, improving reliability through closed-loop control rather than complex open-loop control systems.
Solution Approach 2:
The patent implements dynamic control where switching strategies are continuously adjusted based on real-time voltage conditions. The controller adapts switching patterns dynamically rather than using fixed control parameters, allowing the system to maintain voltage specifications under varying operating conditions without requiring overly complex control architecture.
3Reliability
If DC link voltage sags are prevented, then power quality improves, but loss of time in detection and response increases
Solution Approach 1:
The predictive controller calculates future DC link voltage values before voltage sags actually occur. By predicting upcoming voltage conditions based on historical data and system state, the controller can prepare and implement preventive switching strategies in advance, eliminating the detection and response time delay associated with reactive control systems.
Data Source
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AI summary
A control system (208) for controlling a power inverter (214) of a vehicle (10), the vehicle comprising a first torque source (202), the power inverter for an electric machine (216) coupled to the first torque source, and a second torque source (212), the control system comprising one or more controllers (300), wherein the control system is configured to: enable (412) the power inverter to transition from an active state to a standby state in dependence on the first torque source being inactive while the second torque source is active (400), wherein the standby state is configured to inhibit quiescent electrical current draw by the power inverter; receive information on which an activation condition depends, the activation condition configured to cause at least activation of the first torque source; determine (404, 408) that a predictive condition for a requirement of the activation condition is satisfied, in dependence on the received information; and request (410) the power inverter to transition from the standby state to an active state in dependence on satisfaction of the predictive condition.