Vehicle ePTO Power Coupling With DC Bus Pre-Charge Sequencing
Solution Overview
Problem
Existing systems lack coordination between vehicle electrical power networks and auxiliary electrical systems, leading to risks of high inrush currents and operator safety hazards during connection.
Innovation Solution
The method involves the auxiliary electrical system transmitting an engagement request to the vehicle electrical power network, which then electrically couples the battery to the power take-off point and provides an indication of engagement. The auxiliary system pre-charges its DC bus and closes its contactor only after receiving this indication, ensuring safe and controlled power coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the contactor of the vehicle electrical power network is closed to enable power flow to the ePTO point, then electrical power can be supplied to the auxiliary electrical system, but high inrush current may flow into the auxiliary electrical system during installation which could damage the system
Solution Approach 1:
The auxiliary electrical system transmits an engagement request to the vehicle electrical power network before the contactor is closed. The vehicle power network receives this request and only then closes the contactor to enable power flow, ensuring that the auxiliary system is ready and protected before high current can flow.
Solution Approach 2:
The auxiliary electrical system sends an engagement request signal to the vehicle electrical power network. The vehicle power network responds by closing the contactor only after receiving this request, creating a feedback loop that coordinates the power connection timing and prevents premature high current flow.
2Power
If the contactor of the vehicle electrical power network is closed before manual connection is made, then power can be supplied to the ePTO point, but there is a risk of electric shock to the operator when making the connection
Solution Approach 1:
The auxiliary electrical system must transmit an engagement request before the vehicle power network closes the contactor. This preliminary action ensures that the connection is initiated by the auxiliary system rather than being pre-enabled, reducing the risk of shock to operators performing manual connections.
Solution Approach 2:
The vehicle electrical power network waits for an engagement request from the auxiliary system before closing the contactor. This feedback mechanism ensures that power is only enabled when the auxiliary system is ready and needs it, preventing premature energization that could shock operators.
3Productivity
If manual connection of the auxiliary electrical system to the ePTO point is made without coordination, then the connection can be established quickly, but there is no control over when power flows causing safety risks
Solution Approach 1:
The system implements a coordinated feedback mechanism where the auxiliary electrical system sends an engagement request to the vehicle power network, which then closes the contactor in response. This automated coordination eliminates the need for manual timing judgments while ensuring safe power engagement.
Solution Approach 2:
The manual coordination process is replaced with an automated electrical communication system. The auxiliary system transmits an engagement request signal electronically, and the vehicle power network responds by closing the contactor, replacing manual coordination with automated electrical control.
Data Source
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AI summary
A method (400) for interfacing an auxiliary electrical system (300a, 300b) with an electrical power network (200) of a vehicle (100), the method comprising: i) the auxiliary electrical system transmitting (406) an engagement request to the electrical power network of the vehicle; ii) the electrical power network of the vehicle, responsive to the engagement request transmitted by the auxiliary electrical system, electrically coupling (410) a battery (210) of the electrical power network of the vehicle to an electrical power take-off point (230) of the vehicle and providing (412) an indication to the auxiliary electrical system that electrical power take-off is engaged; iii) the auxiliary electrical system, responsive to the indication that the electrical power take-off is engaged: pre-charging (416) a DC bus of the auxiliary electrical system; and closing (420a, 420b) a contactor (312) of the auxiliary electrical system to electrically couple the auxiliary electrical system to the electrical power take-off point of the vehicle.