4results about How to "Resolve reverse recovery" patented technology

The invention discloses a ZCT soft switching DC / DC converter, which comprises a four-switch tube series main power bridge arm circuit, a passive auxiliary resonance circuit, a voltage and current commutation circuit and an isolation rectification filter circuit, and is characterized in that the main power bridge arm circuit is used for transmitting input power energy; the passive auxiliary resonance circuit is used for cooperating with the working mode of the main power bridge arm circuit, eliminating the switching loss of two high-frequency power switch tubes which are auxiliary switch tubes for each other in the main power bridge arm circuit, and achieving zero-current soft switching. The commutation circuit is used for voltage and current phase switching; the isolation rectification filter circuit is used for rectifying the voltage of the primary side so as to output smooth DC voltage. The two high-frequency modulated power switch tubes serve as main and auxiliary switch tubes of output current in different quadrants, zero-current soft switching of the two high-frequency power switch tubes is achieved on the basis that power switch devices are not increased, switching loss is reduced, efficiency is improved, the working frequency of a system is improved, and the system reliability is improved. The size of the output filter is reduced.

The application discloses a bridgeless Cuk PFC converter based on a switched-inductor-capacitor structure, which comprises switching tubes S1-S3, diodes D1-D4, inductors L1-L5, capacitors C1, C2 and C o The diodes D3 and D4, the capacitor C2 and the inductors L3 and L4 form a switched-inductor-capacitor structure. The original freewheeling diode is replaced by the switched-inductor-capacitor structure, so that the voltage gain of the converter is D / 2(1-D), compared with a traditional Cuk PFC converter, the converter realizes positive voltage output and improves the voltage reduction gain, and the duty cycle range in the voltage reduction mode is wider. Meanwhile, the bridgeless structure is adopted, so that lower on-state loss can be realized. The converter has continuous input and output currents, high power factor and high efficiency, and has rich application.

The utility model provides a kind of bidirectional gallium nitride T type three-level power module and circuit board, wherein, upper bridge arm switch device, midpoint bidirectional switch device and lower bridge arm switch device are all bidirectional gallium nitride power switch;The first drive reference pin of upper bridge arm switch device is connected direct current positive bus;The first drive reference pin of midpoint bidirectional switch device and the first drive reference pin of lower bridge arm switch device are connected to the second drive reference pin of upper bridge arm switch device;The first drive reference pin of midpoint bidirectional switch device and the first drive reference pin of lower bridge arm switch device are also connected to the second drive reference pin of upper bridge arm switch device;The second drive reference pin of midpoint bidirectional switch device is connected direct current neutral line;The second drive reference pin of lower bridge arm switch device is connected direct current negative bus, can reduce the quantity of power tube, reduce conduction loss.

The application discloses a Cuk type power factor correction circuit based on a switching inductor, which comprises switching tubes S1-S3, diodes D1-D5, inductors L1-L5, capacitors C1 and C o Among them, diodes D3-D5 and inductors L3 and L4 form a switching inductor structure.The converter voltage gain is D / (2-D), compared with a traditional Cuk PFC converter, the power factor correction circuit realizes positive voltage output, improves the step-down gain, ensures that the whole duty cycle range is in a step-down state, and the duty cycle is larger than that of the traditional Cuk PFC converter in the case of high step-down ratio, and the emergence of the limit duty cycle condition is effectively avoided.The application of the bridgeless structure can realize lower on-state loss.The power factor correction circuit has the advantages of continuous input and output current, high power factor and high efficiency, and has great practical value.