| 摘要 |
PROBLEM TO BE SOLVED: To provide a power element temperature detector capable of accurately detecting a temperature of a power element at each phase of an inverter with a simple configuration.SOLUTION: The power element temperature detector includes: a CPU 2 incorporating an AD converter 2a and sharing a ground with an inverter 5; upstream resistors UR1, VR1, WR1 connecting between a power source and temperature detection means 1 disposed near a power element IGBT at each phase; and downstream resistors UR8, VR8, WE8 connecting between the temperature detection means 1 and a ground at each phase. The downstream resistors of the temperature detection means 1 have ohmic values such that, when the power element IGBT is turned on and off, a downstream potential of the temperature detection means 1 becomes equal to or greater than a ground level of the AD converter 2a. The CPU 2 measures an end-to-end potential of the temperature detection means 1 and an end-to-end potential of the upstream resistors UR1, VR1, WR1 via the AD converter 2a, divides an end-to-end voltage of the upstream resistor by its ohmic value to obtain a current value, and divides a voltage of the temperature detection means 1 by the value to obtain an ohmic value of the temperature detection means 1. |
