Electrical Heated Catalyst Circuit Topology for Vehicle Exhaust
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Solution Overview
Problem
Existing electrical heated catalyst systems for vehicle exhaust gas purification waste power consumption and lack accurate temperature control, as the catalyst-heating coil is connected to the AC motor, requiring unnecessary motor operation and inadequate current control.
Innovation Solution
A vehicle system where the electrical heated catalyst is connected through branch lines from the power storage device's positive and negative lines, allowing independent control of current for heating using back electromotive force during motor-running mode, enabling precise temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the catalyst-heating coil is connected between the conversion device and AC motor, then the catalyst can be heated by current flowing through the AC motor, but the AC motor must be driven even when torque is not required, causing waste of power consumption
Solution Approach 1:
The patent segments the current path by providing a dedicated catalyst heating coil with its own independent power supply connection to the conversion device. This separates the catalyst heating function from the AC motor operation, allowing the heating coil to be energized independently without requiring the AC motor to run, thus eliminating unnecessary power consumption while maintaining effective catalyst heating.
2Temperature
If the catalyst-heating coil is connected between the conversion device and AC motor, then the catalyst can be heated, but the current applying amount to the catalyst-heating coil cannot be controlled independently of the current applying amount to the AC motor, resulting in unfavorable temperature control accuracy
Solution Approach 1:
The patent segments the electrical circuit into independent paths: one for the AC motor and another for the catalyst heating coil. The heating coil is connected directly to the conversion device with its own control circuitry, enabling independent current control. This segmentation allows precise regulation of heating current without being coupled to AC motor current requirements, achieving favorable temperature control accuracy.
Solution Approach 2:
The patent enables independent control of the heating current parameter by providing a separate control path for the catalyst heating coil. The control device can adjust the current magnitude, duty cycle, or voltage supplied to the heating coil independently of the AC motor operation, allowing precise temperature control through parameter adjustment without being constrained by motor current requirements.
3Device complexity
If the catalyst-heating coil is connected between the conversion device and AC motor, then the system structure is simplified, but the catalyst temperature cannot be controlled with favorable accuracy
Solution Approach 1:
The patent segments the electrical system into independent control modules: the AC motor circuit and the catalyst heating circuit are separated but both connect to the conversion device. This segmentation adds minimal structural complexity while enabling independent current control for the heating coil, achieving precise temperature control without significantly increasing overall system complexity.
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 solution allows for accurate control of catalyst temperature while minimizing power consumption by utilizing back electromotive force for heating, optimizing energy use and performance.
Implementation Method 1
The catalyst device has one end connected to a first branch line branching off from any one of the first plurality of power lines, and heated by current supplied via the first branch line
Implementation Method 2
The first motor is rotated by the power of the second motor transmitted via the planetary gear device to generate back electromotive force
Data Source
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AI summary
A vehicle includes an engine (10), a first MG (20), a second MG (30), a PCU (60), a battery (70), and an EHC (140). The PCU (60) is connected to the battery (70) via a positive line (PLb) and a negative line (NLb). The PCU (60) is connected to the first MG (20) via a 3-phase power line (L1). The PCU (60) is connected to the second MG (30) via a 3-phase power line (L2). The EHC (140) has one end connected to a positive branch line (PLehc) branching off from a W-phase power line (L1w) among the 3-phase power lines (L1) between the PCU (60) and first MG (20). The EHC (140) has the other end connected to a negative branch line (NLehc) branching off from a negative line (NLb) between the PCU (60) and battery (70).