Electrical system integrity testing methods and apparatus

A method for testing an electrical system of an electric vehicle, wherein the electrical system includes a high voltage (HV) energy storage system, an HV bus, a first HV contactor and a second HV contactor coupled between the HV energy storage system and the HV bus, and active discharge circuitry, the method comprising the steps of:

• performing a first diagnostic test to test the functionality of the first HV contactor and the second HV contactor;
• when the first diagnostic test has passed, performing a second diagnostic test to test the functionality of the active discharge circuitry;
• and
• when the second diagnostic test has passed, causing the HV contactors to close to enable an exchange of energy between the HV energy storage system and one or more HV components coupled to the HV bus.

An electrical system comprising:

• a high voltage (HV) energy storage system adapted to store electrical energy;
• an HV bus;
• a set of HV contactors coupled between the HV energy storage system and the HV bus;
• one or more energy consuming components coupled to the HV bus;
• one or more energy supplying components coupled to the HV bus;
• discharge circuitry;
• and
• a control system adapted to perform a first diagnostic test to test the functionality of the HV contactors, to perform a second diagnostic test to test the functionality of the discharge circuitry, and when the first test and the second test have passed, to allow the HV contactors to be closed to enable an exchange of energy between the HV energy storage system, the one or more energy consuming components, and the one or more energy supplying components.