Hybrid Vehicle Voltage Converter Control for Power Loss Reduction
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Solution Overview
Problem
Existing hybrid vehicle power supply systems experience energy loss and poor fuel economy due to constant power loss in voltage converting devices during equal charging and discharging of power supply stages.
Innovation Solution
A control apparatus that manages the operation of multiple power storage devices and voltage converting devices in a hybrid vehicle, selectively activating or deactivating them based on state of charge and power requirements to minimize energy loss, by controlling the first voltage converting device to maintain an ON state and stopping the second during hybrid drive control, and temporarily activating the second device when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple voltage converting devices are operated simultaneously to maintain equal charging/discharging of power supply stages, then the power supply stability is improved, but the power loss in voltage converting devices increases
Solution Approach 1:
The patent applies dynamics by making the operation state of voltage converting devices variable rather than fixed. The control device dynamically adjusts which voltage converting devices operate based on real-time conditions: during electric drive control, both voltage converting devices are operated to maintain power supply stability; during hybrid drive control, only one voltage converting device is operated to reduce power loss. This dynamic adaptation resolves the contradiction between maintaining reliability and reducing energy loss.
Solution Approach 2:
The patent implements periodic action by alternating the operation modes of the voltage converting devices based on driving conditions. The control device switches between two operational patterns: (1) both voltage converting devices operating during electric drive control, and (2) one voltage converting device operating during hybrid drive control. This periodic switching of operational states allows the system to optimize between reliability and energy efficiency at different time periods.
2Power
If both voltage converting devices are operated during hybrid drive control, then the power supply capacity is maintained, but the fuel economy deteriorates
Solution Approach 1:
The patent applies the extraction principle by removing one voltage converting device from operation during hybrid drive control. The control device identifies that during hybrid drive control, only one voltage converting device is needed to maintain sufficient power supply capacity, so it extracts (stops operating) the other voltage converting device. This reduction in the number of operating devices directly reduces power loss and improves fuel economy while maintaining adequate power supply capacity.
3Use of energy by moving object
If voltage converting devices are frequently switched on and off to optimize energy efficiency, then the fuel economy is improved, but the device complexity and control difficulty increase
Solution Approach 1:
The patent manages control complexity through dynamic but rule-based switching. The control device follows clear operational rules: operate both voltage converting devices during electric drive control, and operate only one during hybrid drive control. These dynamic switching rules are based on straightforward condition detection (drive control mode), which keeps the control logic relatively simple despite the dynamic nature of the switching.
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 reduces power loss in voltage converting devices and enhances fuel economy by optimizing the operation of power storage devices and voltage converters based on state of charge and power demand.
Implementation Method 1
a first voltage converting device for converting an output voltage of the first power storage device and outputting the output voltage to the rotating electric machine; a second voltage converting device for converting an output voltage of the second power storage device and outputting the output voltage to the rotating electric machine
Data Source
AI summary
In a hybrid vehicle including: a first battery; a first boost converter for converting an output voltage of the first battery and outputting the output voltage to a motor generator; a second battery; and a second boost converter for converting an output voltage of the second battery and outputting the output voltage to the motor generator, an ECU performs HV drive control for driving the hybrid vehicle by using driving power of both an engine and the motor generator, and stops the second boost converter, when an SOC(1) that is a value indicating a state of charge of the first battery is smaller than a threshold value α or when an SOC(2) that is a value indicating a state of charge of the second battery is smaller than a threshold value β.