Method, based on composite modulation, of data transmission between power electronic devices without communication line

A method based on composite modulation of data transmission between power electronic devices without communication line, comprising:

• in a data transmitting process, utilizing a composite modulation method to include specific data information in a pulse width modulation (PWM) process, and then transmitting the specific data information to a power line through a main power electronic circuit by means of driving pulse signals, so as to accomplish the data transmission process;
• in a data receiving process, extracting signals from voltage and current in the power line, and then obtaining data information through data demodulation, so as to accomplish the data receiving process, wherein, a control module of the power electronic device comprises a main control algorithm module, a signal extraction module, a data demodulation module, a communication processing module, and a composite modulation module, and wherein, the following control scheme is used in the data transmission process:
• 1) the communication processing module is configured to receive, transmit, process, and judge communication signals transmitted through the power line, and the communication processing module generates data signals when data needs to be transmitted;
• 2) the main control algorithm module of the power electronic device employs a pulse width modulation (PWM) mode to control the main power electronic circuit, and the controller contains a main control algorithm, which generates a raw modulation wave according to the voltage and current in the power line and control commands;
• 3) the data signals generated by the communication processing module and the raw modulation wave generated by the main control algorithm are fed into a composite modulation module to accomplish composite modulation.