An optical fiber drive method of power switch in DC full-bridge converter

Abstract

The invention discloses an optical fiber drive method for a power switch in a direct current full-bridge converting circuit, and the method is realized by a photoelectric isolating drive circuit which comprises a controller (1), a PWM converter (2), a photoelectric coupler a (3), an encoder (4), an optical fiber transmitter (5), optical fiber (6), an optical fiber receiver (7) and a decoder (8). The controller (1) controls that a signal is transmitted to the PWM converter (2) and is converted into a PWM signal which is then transmitted to the photoelectric coupler a (3) and is converted into a separating PWM signal, and the separating PWM signal is transmitted to the encoder (4) and is integrated into one combined PWM signal which is then transmitted to the optical fiber transmitter (5), until the four PWM signals are transmitted to a power switch of the direct current full-bridge converter. According to the change of the level of the four PWM signals, the power switch can realize the conduction and disconnection. The invention has the advantages of strong interference rejection, unattenuated optical signal, short time lag produced in transmission and being convenient for long distance transmission.

Description

technical field [0001] The invention relates to a driving method of a power switch, in particular to an optical fiber driving method of a power switch in a DC full-bridge converter. Background technique [0002] In the prior art of DC full-bridge converter, the driving method of the power switch is as follows: the controller generates a control signal, and transmits the control signal to a PWM (pulse width modulation converter), and the PWM converter converts the control signal into a PWM wave, and passes the The cable transmits the PWM wave to each power switch in the full-bridge converter, and each power switch is turned on and off according to the change of the level of the PWM wave. For example, Sun Tiecheng, Tang Pinghua, Gao Peng, and Liu Hongpeng wrote "A New Type of Full-Bridge Zero-Voltage PWM DC-DC Converter" in "Chinese Journal of Electrical Engineering", March 2006, Volume 26, Issue 6 , which describes this method of sending PWM waves directly through a cable an...

AI Technical Summary

Problems solved by technology

The disadvantage of this driving method is: the PWM signal is directly transmitted through the cable, and there is no electrical isolation between the transmission line, the control line and the switch tube, the system is easily interfered by other signals, and due to the existence of the cable's own impedance, it will also Causes attenuation of the signal, so additional anti-interference measures need to be taken, and the transmission distance is also limited and cannot be too long

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