Contactless power transfer system and method for controlling the same
A contactless power transfer system is provided. The contactless power transfer system includes a first power exchanger coil configured to exchange power. The contactless power transfer system also includes a first power converter operatively coupled to the first power exchanger coil and configured to convert a direct current power to an alternating current power at a system frequency. The contactless power transfer system further includes a controller configured to control an operating state of the first power converter to vary an alternating current power provided to the first power exchanger coil at the system frequency.
1 . A method for contactless power transfer, the method comprising:
transmitting, by a first power exchanger coil, wireless power to a wireless power receiving device during a plurality of intermittent first time periods, wherein each first time period of the plurality of intermittent first time periods is followed by a second time period in which the first power exchanger coil does not transmit the wireless power; and
controlling a duration of the plurality of intermittent first time periods based on a power requirement of the wireless power receiving device.
2 . The method of claim 1 , further comprising:
changing the duration of the plurality of intermittent first time periods based on a change in the power requirement of the wireless power receiving device.
3 . The method of claim 1 , further comprising:
generating an alternating current (AC) power at a fixed frequency; and
providing the AC power to the first power exchanger coil for transmission of the wireless power.
4 . The method of claim 3 , wherein the fixed frequency remains constant for different power requirements of the wireless power receiving device.
5 . The method of claim 1 , wherein the power requirement is associated with a load of the wireless power receiving device.
6 . The method of claim 1 , wherein an amount of power transfer is controlled by varying the duration of the plurality of intermittent first time periods.
7 . The method of claim 1 , wherein controlling the duration of the plurality of intermittent first time periods comprises causing the first power exchanger coil to transmit pulses of the wireless power such that an average of the pulses satisfies the power requirement.
8 . The method of claim 1 , wherein controlling the duration of the plurality of intermittent first time periods comprises:
controlling the duration of the plurality of intermittent first time periods based, at least in part, on a direct current power measured at a first node located between a second power exchanger coil of the wireless power receiving device and a load of the wireless power receiving device.
9 . The method of claim 8 , further comprising:
receiving, via a wireless communication unit, a communication from the wireless power receiving device that indicates at least a voltage indicative of the direct current power measured at the first node.
10 . The method of claim 1 , further comprising:
generating a plurality of cycles of an alternating current (AC) power at a system frequency during each first time period; and
halting generation of the AC power during the second time period.
11 . A contactless power transfer system, comprising:
a first power exchanger coil configured to transmit wireless power to a wireless power receiving device during a plurality of intermittent first time periods, wherein each first time period of the plurality of intermittent first time periods is followed by a second time period in which the first power exchanger coil does not transmit the wireless power; and
a controller configured to control a duration of the plurality of intermittent first time periods based on a power requirement of the wireless power receiving device.
12 . The contactless power transfer system of claim 11 , wherein the controller is further configured to:
change the duration of the plurality of intermittent first time periods based on a change in the power requirement of the wireless power receiving device.
13 . The contactless power transfer system of claim 11 , further comprising:
a power converter configured to generate an alternating current (AC) power at a fixed frequency and provide the AC power to the first power exchanger coil for transmission of the wireless power.
14 . The contactless power transfer system of claim 13 , wherein the fixed frequency remains constant for different power requirements of the wireless power receiving device.
15 . The contactless power transfer system of claim 11 , wherein the power requirement is associated with a load of the wireless power receiving device.
16 . The contactless power transfer system of claim 11 , wherein the controller is further configured to control an amount of power transferred by varying the duration of the plurality of intermittent first time periods.
17 . The contactless power transfer system of claim 11 , wherein the first power exchanger coil transmits pulses of the wireless power such that an average of the pulses satisfies the power requirement.
18 . The contactless power transfer system of claim 11 , wherein the controller is configured to control the duration of intermittent first time periods based, at least in part, on a direct current power measured at a first node located between a second power exchanger coil of the wireless power receiving device and a load of the wireless power receiving device.
19 . The contactless power transfer system of claim 18 , further comprising:
a wireless communication unit configured to receive a communication from the wireless power receiving device that indicates at least a voltage indicative of the direct current power measured at the first node.