Electrical leak detecting apparatus for an electric vehicle

An electrical leak detecting apparatus for an electric vehicle, the apparatus comprising:

• a first switch and a second switch connected to each other in series between a maximum potential terminal and a minimum potential terminal of a battery pack;
• a detection resistor having one end connected to a common contact of the first and second switches;
• and
• a first measured potential supply unit and a second measured potential supply unit providing first and second measured potentials, of different potential, to the battery pack,
• wherein the first measured potential supply unit or the second measured potential supply unit is connected between the other end of the detection resistor and a vehicle body in parallel, and
• one of the first measured potential and the second measured potential is provided to the battery pack.

An electrical leak detecting apparatus for an electric vehicle, the apparatus comprising:

• a first switch element connected to a positive electrode of a battery pack in parallel;
• a second switch element not only connected to a negative electrode of the battery pack in parallel but also connected to the first switch element in series;
• a voltage distribution resistor connected to the first and second switch elements in series;
• a detection resistor connected between the voltage distribution resistor and a measured potential supply unit in series;
• the measured potential supply unit and a vehicle body connected to the detection resistor in series;
• and
• a ground switch connected between the detection resistor and the vehicle body and grounding the detection resistor and the vehicle body.

A method of detecting an electrical leak for an electric vehicle, the method comprising:

• detecting a first voltage of a detection resistor when first and second polarity conversion switches are turned on with a first polarity, a first switch is turned off, a second switch is turned on and a ground switch is turned off;
• detecting a second voltage of the detection resistor by turning on the ground switch;
• obtaining a third voltage of the detection resistor by using a measured potential supply unit by subtracting the second voltage of the detection resistor from the first voltage of the detection resistor;
• detecting a fourth voltage of the detection resistor when the first and second polarity conversion switches are turned on with a second polarity, the first switch is turned on, the second switch is turned off and the ground switch is turned off;
• detecting a fifth voltage of the detection resistor by turning on the ground switch;
• obtaining a sixth voltage of the detection resistor by using the measured potential supply unit by subtracting the fifth voltage of the detection resistor from the fourth voltage of the detection resistor;
• and
• if the third voltage of the detection resistor is detected, determining maximum potential insulation failure, if the sixth voltage of the detection resistor is detected, determining minimum potential insulation failure, and if both the third voltage and the sixth voltage of the detection resistor are detected as insulation failure, determining intermediate potential insulation failure.