Electrical isolation detection with enhanced dynamic range
AssigneeDeere & Company
InventorsRyan W. Schumacher, Perry K. White
Life of this patent
Estimating the term…
Abstract
A bus terminal is isolated from ground potential during normal operation of the vehicle. A first current is applied to the bus terminal. A current level detector is arranged to detect a first level of the first current, or a corresponding observed voltage level, that exists or flows from the bus terminal to ground. A compensator is configured to compensate for a range in the detected first level by applying a corresponding compensating voltage level to a first resistor coupled to the current level detector. An electronic data processor is capable of estimating a first isolation level between the bus terminal and ground based on the detected first level.
Claims18
A method for detecting electrical isolation between a bus terminal and ground, or chassis reference, on a vehicle, the system comprising:
- providing a bus terminal isolated from the ground and chassis reference during normal operation of the vehicle;
- applying a first current to the bus terminal;
- detecting a first level of the first current, or a corresponding observed voltage level based on the first current, that flows or exists from the bus terminal to ground, by compensating for a range in the detected first level by applying a corresponding compensating voltage level to a resistive network coupled to a level detector for detecting the first level based upon certain observed reference voltage levels;
- and
- estimating a first isolation level between the bus terminal and the ground, or the chassis reference, based on the detected first level, wherein the compensating voltage places the first level within a target measurement range for detection by the level detector, where the target measurement range is consistent with an input voltage range of an analog-to-digital converter coupled to the level detector.
A system for detecting electrical isolation between a bus terminal and ground, or the chassis reference, on a vehicle, the system comprising:
- a bus terminal isolated from the ground and chassis reference during normal operation of the vehicle, a first current applied to the bus terminal;
- a detector for detecting a first level of the first current, or a corresponding observed voltage, based on the first current, that flows or exists from the bus terminal to ground;
- a compensator for compensating for a range in the detected first level by applying a corresponding compensating voltage level to a resistive network coupled to the detector, the compensating voltage levels determined based upon certain observed reference voltage levels, wherein the compensating voltage level places the first level within a target measurement range for detection by the detector, where the target measurement range is consistent with an input voltage range of an analog-to-digital converter coupled to the level detector;
- and
- an electronic data processor for estimating a first isolation level between the bus terminal and ground based on the detected first level.
A method for detecting electrical isolation between a bus terminal and ground, or chassis reference, on a vehicle, the system comprising:
- providing a bus terminal isolated from the ground and chassis reference during normal operation of the vehicle;
- applying a first current to the bus terminal;
- detecting a first level of the first current, or a corresponding observed voltage level based on the first current, that flows or exists from the bus terminal to ground, by compensating for a range in the detected first level by applying a corresponding compensating voltage level to a resistive network coupled to a level detector for detecting the first level based upon certain observed reference voltage levels;
- and
- estimating a first isolation level between the bus terminal and the ground, or the chassis reference, based on the detected first level, wherein the compensating voltage places the first level within a target measurement range for detection by the level detector to increase dynamic range of the electrical isolation detection, regardless of whether or not a ground fault or decrease in isolation is present.
Dependencies are inferred from the claim text.