Method of switching synchronization of parallel-connected converter system

A switching synchronization method for a parallel converter system having a plurality of converters parallel connected through a synchronizing signal bus, comprising setting one of the converters as a host converter, and setting the others as slave converters, wherein said host converter includes at least a first timer and a pulse transmitting device, and each of said slave converters includes at least a second timer, a pulse edge capture device as well as a synchronization adjuster, said converter system carrying out the following steps to synchronize switches:

• (1) the first timer of the host converter being used to send synchronization pulses to the synchronization bus at a predetermined time (Tk1) through said pulse transmitting device;
• (2) the second timer of each of the slave converters recording the time (Tx) of the edge of the synchronization pulse received by said capture device from the synchronization bus;
• and
• (3) on the basis of said times Tk1 and Tx said synchronization adjuster calculating the synchronization algorithm, adjusting the second timer in said slave converters to be synchronized with the first timer of the host converter, and then according to a predetermined protocol, the switching carrier timer in each of the slave converters being adjusted to synchronize with a switching carrier timer of the host converter.