Vehicular Power Supply Relay Circuit Reduction
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Solution Overview
Problem
The existing vehicular power supply systems face issues with power loss and reduced torque during engine starting due to transistors in the switch circuit, and inefficient charging due to power loss, along with the need for two relay circuits that increase power consumption and complexity.
Innovation Solution
A vehicular power supply system that reduces the number of relay circuits to one by using a control circuit to detect voltage and manage the relay coil and switching elements, incorporating MOS transistors and diodes in the three-phase bridge circuit for efficient power conversion and charging, and arranges the switch circuit for synchronous rectification or phase control to minimize power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If transistors are used in the switch circuit to control power conversion, then power conversion capability is improved, but power loss increases and torque decreases during engine starting
Solution Approach 1:
The patent removes the transistor switch circuit from the battery charging path entirely. Instead of using transistors Q7A to Q9A for switching, the system uses the intrinsic body diodes of the MOS transistors Q1 to Q6 in the three-phase bridge circuit for synchronous rectification, eliminating the source of power loss in the charging path.
Solution Approach 2:
The patent replaces the active transistor switching mechanism with passive synchronous rectification using body diodes. This substitution eliminates the voltage drop and power loss associated with active transistor switching while maintaining the power conversion function through controlled rectification.
2Reliability
If two relay circuits are used to control battery charging and motor driving, then starting performance is ensured, but device complexity and power consumption increase
Solution Approach 1:
The patent merges the functions of two separate relay circuits into a single relay circuit RY1. The relay controller CONA intelligently controls this single relay to perform both the battery charging function and the motor driving function, reducing component count while maintaining functional reliability through centralized control logic.
Solution Approach 2:
The single relay circuit RY1 is designed to perform multiple functions: it controls both battery charging operations and motor driving operations. The relay controller CONA manages different operational modes (charging, motor drive, kick-start) using this universal relay, eliminating the need for dedicated relay circuits for each function.
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 configuration reduces power loss and the number of relay circuits, improving engine starting torque and charging efficiency by optimizing the relay circuit and switch circuit operations based on battery voltage levels.
Implementation Method 1
performing rectification control or phase control for AC power supplied from the motor M
Implementation Method 2
performing rectification control or phase control for AC power supplied from the motor M
Implementation Method 3
a smoothing capacitor C having one end connected to an output terminal TOUT and the other end connected to the negative electrode of the battery B
Implementation Method 4
a relay circuit RY1 having a first contact C1, a second contact C2 connected to the positive electrode of the battery B, and adapted to electrically connect the first contact C1 to the second contact C2 when turned on and to interrupt electrical connection between the first contact C1 and the second contact C2 when turned off
Implementation Method 5
arranges the switch circuit for synchronous rectification or phase control to minimize power loss
Data Source
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AI summary
A vehicular power supply system comprises: a first control MOS transistor having one end connected to the one end of the three-phase bridge circuit and the other end connected to the output terminal; a first control body diode having a cathode connected to the one end of the first control MOS transistor and an anode connected to the other end of the first control MOS transistor; a second control MOS transistor having one end connected to the output terminal and the other end connected to the positive electrode of the battery; a second control body diode having a cathode connected to the one end of the second control MOS transistor and an anode connected to the other end of the second control MOS transistor.