Method, controller and system for handling isolation faults in battery operated system

A computer program product stored on a non-transitory computer-readable medium, said computer program product for handling isolation faults in a battery operated high voltage electric system for propelling a vehicle, the system comprising a plurality of propulsion battery packs and at least one electric machine connected to said plurality of propulsion battery packs, wherein said computer program product comprising computer instructions to cause one or more controllers to perform the following operations:

• perform isolation measurement of the system when in operation;
• if an isolation fault is detected in the system, then disconnect all propulsion battery packs;
• measure isolation resistance between a plus side of each battery pack and ground and measure isolation resistance between a minus side of each battery pack and ground;
• and
• if the measured isolation resistance in a battery pack is above a pre-determined value, re-connect that battery pack, and if the measured isolation resistance is below a pre-determined value in a battery pack, maintain that battery pack disconnected.

A controller for handling isolation faults in a battery operated high voltage electric system for propelling a vehicle, the high voltage electric system comprising a plurality of propulsion battery packs, each propulsion battery pack provided with contactors, each battery pack provided with means for measuring isolation resistance connected to said controller, and at least one electric machine connected to said plurality of battery packs, wherein the controller is configured to:

• verify that the system is in operation;
• an isolation fault in the system during operation is detected, then activate said contactors for disconnecting all propulsion battery packs
• obtain information from the isolation resistance measuring means regarding the isolation resistance between a plus side of each battery pack and ground and the isolation resistance between a minus side of each battery pack and ground;
• and
• activate the contactors of a battery pack for re-connection to the system if the obtained isolation resistance value in that battery pack is above a pre-determined value, and maintain a battery pack disconnected from the system if the obtained isolation resistance value in that battery pack is below a pre-determined value.

A high voltage electric system for propelling a vehicle, the system comprising:

• a plurality of propulsion battery packs each battery pack comprising contactors and means for measuring isolation resistance;
• at least one electric machine connected to said plurality of propulsion battery packs;
• and
• a controller for handling isolation faults, said controller configured to:
• verify that the system is in operation;
• if an isolation fault in the system during operation is detected, then activate said contactors for disconnecting all propulsion battery packs;
• obtain information from the isolation resistance measuring means regarding the isolation resistance between a plus side of each battery pack and ground and the isolation resistance between a minus side of each battery pack and ground;
• and
• activate the contactors of a battery pack for re-connection to the system if the obtained isolation resistance value in that battery pack is above a pre-determined value, and maintain a battery pack disconnected from the system if the obtained isolation resistance value in that battery pack is below a pre-determined value.

A vehicle comprising a high voltage electric system for propelling the vehicle, the high voltage electric system comprising:

• a plurality of propulsion battery packs, each battery pack comprising contactors and means for measuring isolation resistance;
• at least one electric machine connected to said plurality of propulsion battery packs;
• and
• a controller for handling isolation faults, said controller configured to:
• verify that the system is in operation;
• if an isolation fault in the system during operation is detected, then activate said contactors for disconnecting all propulsion battery packs;
• obtain information from the isolation resistance measuring means regarding the isolation resistance between a plus side of each battery pack and ground and the isolation resistance between a minus side of each battery pack and ground;
• and
• activate the contactors of a battery pack for re-connection to the system if the obtained isolation resistance value in that battery pack is above a pre-determined value, and maintain a battery pack disconnected from the system if the obtained isolation resistance value in that battery pack is below a pre-determined value.