Abstract: A power transmission device includes a movable part which comes up and down with respect to the ground, and an elevating mechanism which moves the movable part up and down. A defrosting method for a power transmission device measures a temperature of the power transmission device, and compares the measured temperature with a threshold preliminarily set for determining a freeze of the power transmission device so as to determine whether the power transmission device is frozen. The defrosting method for a power transmission device excites a power transmission coil when determining that the power transmission device is frozen.

Abstract: A charging controller (25) acquires the power loss of a power transmission coil (31) from a power supply device (100) via wireless communication. A temperature estimation unit (33) estimates the ambient temperature of a power reception coil on the basis of a preset amount of heat generation of a power reception device (200) and the power loss of the power transmission coil (31). In this case, when the positional relationship between the power transmission coil (31) and the power reception coil (41) is shifted from a normal positional relationship, the temperature estimation unit (33) increases, in accordance with the magnitude of positional shift amount, the contribution to a temperature rise due to the power loss of the power transmission coil (31). Accordingly, an abnormal increase in the ambient temperature of the power reception coil (41) can be prevented.

Abstract: A charging controller (25) acquires the power loss of a power transmission coil (31) from a power supply device (100) via wireless communication. A temperature estimation unit (33) estimates the ambient temperature of a power reception coil on the basis of a preset amount of heat generation of a power reception device (200) and the power loss of the power transmission coil (31). In this case, when the positional relationship between the power transmission coil (31) and the power reception coil (41) is shifted from a normal positional relationship, the temperature estimation unit (33) increases, in accordance with the magnitude of positional shift amount, the contribution to a temperature rise due to the power loss of the power transmission coil (31). Accordingly, an abnormal increase in the ambient temperature of the power reception coil (41) can be prevented.

Abstract: A vehicle-mounting structure for a wireless power reception device includes: a power-reception-side coil unit (23) including a power-reception-side coil (49) configured to wirelessly receive power transmitted from a power-supply-side coil; and a junction box (13) accommodating a rectifier (45) and mounted on a front part of the upper surface (23a) of the power-reception-side coil unit (23). A floor tunnel part (7) and the power-reception-side coil unit (23) form a closed-cross-section part (61), and the junction box (13) is accommodated in the closed-cross-section part (61). A rear part of the upper surface (23a) of the power-reception-side coil unit (23) is formed as an upward-airflow generation surface (47) configured to generate an upward airflow with heat of the power-reception-side coil (49).

Abstract: A vehicle-mounting structure for a wireless power reception device includes: a power-reception-side coil unit (23) including a power-reception-side coil (49) configured to wirelessly receive power transmitted from a power-supply-side coil; and a junction box (13) accommodating a rectifier (45) and mounted on a front part of the upper surface (23a) of the power-reception-side coil unit (23). A floor tunnel part (7) and the power-reception-side coil unit (23) form a closed-cross-section part (61), and the junction box (13) is accommodated in the closed-cross-section part (61). A rear part of the upper surface (23a) of the power-reception-side coil unit (23) is formed as an upward-airflow generation surface (47) configured to generate an upward airflow with heat of the power-reception-side coil (49).