Power conversion apparatus and charging apparatus

1 . A power conversion apparatus, comprising: an alternating current-direct current (AC-DC) conversion circuit; a power controller connected to the AC-DC conversion circuit, and the power controller is configured to: control the AC-DC conversion circuit to receive an alternating current, convert the alternating current into a first direct current, and output the first direct current; a circulating current controller configured to send a synchronization signal to another power conversion apparatus through a controller area network (CAN) bus and the synchronization signal is used to synchronize a carrier of the another power conversion apparatus with a carrier of the power conversion apparatus; and

a circulating current detection circuit, and the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to: detect a circulating current value at the input end of the AC-DC conversion circuit, and transmit the circulating current value to the circulating current controller, and the circulating current controller is further configured to: receive a first modulated wave from the power controller, and adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, wherein the second modulated wave is used to determine a drive signal and the drive signal is used to control turn-on time of the plurality of switches.

2 . The power conversion apparatus according to claim 1 , wherein the circulating current controller comprises:

a first primary timer configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the power conversion apparatus to be synchronized with a target carrier period, and the target carrier period is synchronized with a period of the carrier of the another power conversion apparatus.

3 . The power conversion apparatus according to claim 2 , wherein the circulating current controller further comprises:

a first secondary timer connected to the first primary timer, and the first primary timer is further configured to:

when a count value of the first primary timer is a period value of the target carrier period, send a first trigger signal to the first secondary timer, wherein the first trigger signal indicates to reset a count value of the first secondary timer, so that the first primary timer is synchronized with the first secondary timer.

4 . The power conversion apparatus according to claim 2 , wherein the circulating current controller further comprises:

a synchronization timer connected to the first primary timer and the another power conversion apparatus, and the synchronization timer is configured to:

when a count value of the synchronization timer is a first period value, send the synchronization signal to the first primary timer and the another power conversion apparatus.

5 . The power conversion apparatus according to claim 1 , wherein the circulating current controller is further configured to: determine a circulating current deviation based on the circulating current value and a preset circulating current threshold; perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.

6 . The power conversion apparatus according to claim 1 , wherein the circulating current controller is further configured to: send the second modulated wave to the power controller; and the power controller is further configured to: determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.

7 . A power conversion apparatus, comprising: an alternating current-direct current (AC-DC) conversion circuit; a power controller connected to the AC-DC conversion circuit, and the power controller is configured to control the AC-DC conversion circuit to receive an alternating current, convert the alternating current into a first direct current, and output the first direct current; and a circulating current controller configured to receive a synchronization signal from another power conversion apparatus through a controller area network (CAN) bus and the synchronization signal is used to synchronize a carrier of the power conversion apparatus with a carrier of the another power conversion apparatus; and

a circulating current detection circuit, the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to: detect a circulating current value at the input end of the AC-DC conversion circuit, and transmit the circulating current value to the circulating current controller; and the circulating current controller is further configured to: receive a first modulated wave from the power controller and adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, the second modulated wave is used to determine a drive signal, and the drive signal is used to control turn-on time of the plurality of switches.

8 . The power conversion apparatus according to claim 7 , wherein the circulating current controller comprises:

a second primary timer configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the power conversion apparatus to be synchronized with a target carrier period, and the target carrier period is synchronized with a period of the carrier of the another power conversion apparatus.

9 . The power conversion apparatus according to claim 8 , wherein the circulating current controller further comprises:

a second secondary timer connected to the second primary timer, and the second primary timer is further configured to:

when a count value of the second primary timer is a period value of the target carrier period, send a second trigger signal to the second secondary timer, and the second trigger signal indicates to reset a count value of the second secondary timer, so that the second primary timer is synchronized with the second secondary timer.

10 . The power conversion apparatus according to claim 7 , wherein the circulating current controller is further configured to: determine a circulating current deviation based on the circulating current value and a preset circulating current threshold; perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.

11 . The power conversion apparatus according to claim 7 , wherein the circulating current controller is further configured to: send the second modulated wave to the power controller; and the power controller is further configured to: determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.

12 . A charging apparatus, comprising a plurality of power conversion apparatuses and a direct current bus, wherein the plurality of power conversion apparatuses are disposed in parallel, and each of the plurality of power conversion apparatuses comprises: an alternating current-direct current (AC-DC) conversion circuit; a power controller connected to the AC-DC conversion circuit, and the power controller is configured to: control the AC-DC conversion circuit to receive an alternating current, convert the alternating current into a first direct current, and output the first direct current through the direct current bus; and a circulating current controller; the plurality of power conversion apparatuses comprise a primary power conversion apparatus and at least one secondary power conversion apparatus, a circulating current controller of the primary power conversion apparatus is a primary circulating current controller, and a circulating current controller of the secondary power conversion apparatus is a secondary circulating current controller; and the primary circulating current controller is configured to: send a synchronization signal to the secondary circulating current controller through a controller area network (CAN) bus, and the synchronization signal is used to synchronize a carrier of the secondary power conversion apparatus with a carrier of the primary power conversion apparatus; and

a circulating current detection circuit, the AC-DC conversion circuit comprises a plurality of switches, the circulating current detection circuit is connected to an input end of the AC-DC conversion circuit and the circulating current controller, and the circulating current detection circuit is configured to: detect a circulating current value at the input end of the AC-DC conversion circuit and transmit the circulating current value to the circulating current controller; and the circulating current controller is configured to: receive a first modulated wave from the power controller and adjust the first modulated wave based on the circulating current value, to obtain a second modulated wave, and the second modulated wave is used to determine a drive signal, and the drive signal is used to control turn-on time of the plurality of switches.

13 . The charging apparatus according to claim 12 , wherein the primary circulating current controller comprises a first primary timer, and the secondary circulating current controller comprises a second primary timer;

the first primary timer is configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the primary power conversion apparatus to be synchronized with a target carrier period; and

the second primary timer is configured to adjust, based on edge triggering of the synchronization signal, a period of the carrier of the secondary power conversion apparatus to be synchronized with the target carrier period.

14 . The charging apparatus according to claim 13 , wherein the primary circulating current controller further comprises a first secondary timer, and the secondary circulating current controller further comprises a second secondary timer;

the first secondary timer is connected to the first primary timer, and the second secondary timer is connected to the second primary timer;

the first primary timer is further configured to:

when a count value of the first primary timer is a period value of the target carrier period, send a first trigger signal to the first secondary timer, and the first trigger signal indicates to reset a count value of the first secondary timer, so that the first primary timer is synchronized with the first secondary timer; and

the second primary timer is further configured to:

when a count value of the second primary timer is the period value of the target carrier period, send a second trigger signal to the second secondary timer, and the second trigger signal indicates to reset a count value of the second secondary timer, so that the second primary timer is synchronized with the second secondary timer.

15 . The charging apparatus according to claim 13 , wherein the primary circulating current controller further comprises a synchronization timer, and the synchronization timer is connected to the first primary timer and the second primary timer; and

the synchronization timer is configured to:

when a count value of the synchronization timer is a first period value, send the synchronization signal to the first primary timer and the second primary timer.

16 . The charging apparatus according to claim 12 , wherein the circulating current controller is further configured to: determine a circulating current deviation based on the circulating current value and a preset circulating current threshold; perform operation adjustment on the circulating current deviation, to obtain a first compensation amount; and perform superposition processing on the first compensation amount and the first modulated wave, to obtain the second modulated wave.

17 . The charging apparatus according to claim 12 , wherein the circulating current controller is further configured to: send the second modulated wave to the power controller; and the power controller is further configured to: determine the drive signal based on the second modulated wave and the carrier of the power conversion apparatus.