38results about How to "Suppress reverse recovery issues" patented technology

The invention discloses a low-additional-voltage zero-voltage switch energy storage bridge type inverter and a modulation method. The low-additional-voltage zero-voltage switch energy storage bridge type inverter comprises a direct-current side storage battery, a direct-current capacitor, an alternating-current filter inductor and a single-phase bridge arm, wherein the single phase bridge arm is formed by four full-control master switches with anti-parallel diodes, a series branch of an auxiliary switch with an anti-parallel diode and a clamping capacitor is connected between the direct-current side storage battery and a direct-current bus of the single-phase bridge arm, two ends of the branch are connected with resonance inductors, and two ends of the master switches and the auxiliary switch are in parallel connection with the capacitor. The low-additional-voltage zero-voltage switch energy storage bridge type inverter can independently run with load or runs in a grid-connection mode and is simple in structure, power can flow bidirectionally to charge and discharge the storage battery, the master switch uses a sine wave pulse width modulation method, and modulation signals of the master switches are synchronous with the auxiliary switch. In one switching period, the auxiliary switch only works once to enable all master switches to achieve zero-voltage switching. Reverse recovery current of the anti-parallel diodes of the master switches can be restrained so as to be small in switching loss, high in circuit efficiency and favorable for improving efficiency to improve power density.

The invention provides an additional-voltage-free zero voltage switch energy-storing semi-bridge type inverter and a modulation method. The inverter comprises a direct current side storage battery, a direct current side voltage division capacitor, an alternating current side filtering inductor and a single-phase bridge arm formed by two full control main switches with antiparallel diodes. An auxiliary switch of the antiparallel diodes is connected between direct current buses of the voltage division capacitor and the single-phase bridge arm. Capacitors are connected at two ends of the main switches and the auxiliary switch, and a resonant branch formed by connecting a resonant inductor and a clamping capacitor is connected at two ends of the auxiliary switch in bridge mode. The inverter runs independently with load or in grid-connection mode. The main switches adopt a sine wave pulse width modulation method, and modulation signals of the auxiliary switch are synchronous with modulation signals of the main switches. In each on-off period, the auxiliary switch can achieve zero voltage opening of the main switches by simply acting once, reverse current restoring of the antiparallel diodes of the main switches is restrained, and the switch voltage stress is equal to the direct current side voltage of the inverter. The inverter is small in switch consumption, high in circuit efficiency and favorable for improving working efficiency and further improves power density.

The invention discloses a zero-voltage switch modulation method of a three-phase four-wire system zero-voltage switch inverter. The modulation method compares the three-phase main switch modulation wave of the three-phase four-wire zero-voltage switching inverter with the sawtooth carrier, and then generates the main switch signal through the inverter and the rising edge delay module, and converts the three-phase four-wire zero-voltage switching The auxiliary switch modulation wave of the voltage switch inverter is compared with the sawtooth carrier, and then the bridge arm through signal and the auxiliary switch signal are generated by the rising edge delay module, the inverter and the falling edge delay module. In the three-phase four-wire zero voltage switch During the commutation period of the fully-controlled main switch of the inverter, the through signal is applied to the fully-controlled main switch to provide a freewheeling circuit for the magnetization of the resonant inductor to store sufficient resonance energy. The invention has a simple structure, can realize full-range soft switching in the power frequency cycle, realizes zero-voltage turn-on of all switching devices, has small switching loss, high circuit efficiency, can suppress reverse recovery of diodes, and reduces electromagnetic interference.

The embodiment of the invention discloses a bridge arm used in a motor drive circuit and a control method thereof, which relate to the technical field of electrical equipment and electrical engineering, and can suppress the reverse recovery problem of the MOSFET body diode of the motor bridge arm under the condition of high current, and reduce the power consumption of the motor. Drive circuit loss, improve system efficiency. The invention comprises: bridge arm switch tube, bridge arm optimized switch tube, reverse series switch tube, reverse parallel diode, driver and delay link. Wherein, the reverse series switch tube can be connected in series with the switch tube of the upper bridge arm, or can be connected in series with the switch tube of the lower bridge arm, and can also be optimized to reduce the switching loss of the upper and lower bridge arms simultaneously by using two reverse series switch tubes. The anti-parallel diode is connected in parallel to the bridge arm with the anti-series switch. The invention is suitable for the reverse recovery suppression of the bridge arm of the motor.