Detection and warning of thermal hazard in electrical energy storage systems

A computer-implemented method, comprising:

• detecting, by processing circuitry of a computer system, an isolation fault in an electrical energy storage system comprising multiple electrical energy storage packs connected in parallel to a voltage bus, the electrical energy storage packs each comprising a set of electrical energy storage cells;
• disconnecting, by the processing circuitry, all but one electrical energy storage pack from the voltage bus;
• determining, by the processing circuitry, an isolation resistance for each of the disconnected electrical energy storage packs,
• determining, by the processing circuitry, electrical energy storage cell temperatures for at least two cells in each of the disconnected electrical energy storage packs,
• providing, by the processing circuitry, a first thermal runaway warning signal when the isolation resistance is below a predetermined threshold, and
• providing, by the processing circuitry, a second thermal runaway warning signal when one of the electrical energy storage cell temperatures of an electrical energy storage pack exceeds a temperature threshold, and a first temperature difference between any two electrical energy storage cells of the same electrical energy storage pack exceeds a first temperature difference threshold, and
• providing, by the processing circuitry, a third thermal runaway warning signal when one of the electrical energy storage cell temperatures of an electrical energy storage pack exceeds the temperature threshold, and a second temperature difference between any two electrical energy storage cells of the same electrical energy storage pack exceeds a second temperature difference threshold.