Wireless power transfer system, wireless power transmitting device, and wireless power receiving device

A wireless power transmitting device configured to wirelessly transmit power to a power receiving device, the power transmitting device comprising:

• a communication device configured to communicate With the power receiving device;
• and
• a controller configured to control power transmission to the power receiving device,
• the controller being configured to:
• when an abnormality occurs in the power transmitting device during power transmission to the power receiving device, stop power transmission to the power receiving device;
• and
• when receiving from the power receiving device a request for resuming power transmission while the power transmission is stopped, resume the power transmission.

A wireless power receiving device configured to wirelessly receive power from a power transmitting device, the power receiving device comprising:

• a communication device configured to communicate with the power transmitting device;
• and
• a controller configured to control the communication device,
• the controller being configured to:
• when power transmission from the power transmitting device is stopped due to an abnormality in the power transmitting device, transition to a sleep state;
• and
• when a first time has elapsed since the transition to the sleep state, send the power transmitting device a request for resuming power transmission.