121results about How to "Reduce voltage spikes" patented technology

A voltage boost power converter circuit, having an input inductor, active switch, and a transformer having primary, secondary and auxiliary windings. A clamping capacitor and a first passive switch are in series across the primary winding. The auxiliary winding and a second passive switch are in series, connected to the node between the clamping capacitor and first passive switch. The active switch is connected between ground the primary winding. A bulk capacitor forms a series loop including the active switch and primary winding. The method efficiently resets a the transformer, by transferring power to a load through the primary winding, and discharging a clamping capacitor through a separate inductively linked winding of the transformer during an ON state; and clamping the active switch voltage with the clamping capacitor, charging the clamping capacitor with a leakage inductance of the transformer, and charging the bulk capacitor during an OFF state.

This invention relates to three-level switch power amplifier belonging to voltage to current switch power amplifier, which comprises Signal mixture process circuit, impulse modulation circuit, protective and light coupling drive circuit and the voltage signal drive bridge circuit to control the signal to get relative voltage signals to control the load current size. The double electrode power amplifier without bias current has wide application prospect.

Power system and method for providing electrical power are provided. The system includes a traction system and auxiliary equipment coupled to a power bus. The traction system includes one or more electromotive machines having a first type of stator winding that provides protection relative to voltage spikes expected at the traction stator under a first voltage level appropriate for the traction system. The auxiliary equipment includes one or more electromotive machines having a second type of stator winding that provides protection relative to spikes expected at the auxiliary stator under a second voltage level lower than the first voltage level. Inverter circuitry is coupled to drive the auxiliary equipment, and signal-conditioning circuitry is provided to attenuate voltage spikes produced by the inverter circuitry. The power bus is operated at the first voltage level, and the voltage spike attenuation is sufficient to protect the auxiliary stator.

An absorption circuit for a voltage spike of a switching tube of a DC converter power includes: a transformer T1, a first commuting power tube Q1, a second commuting power tube Q2, a first clamp diode Ds1, a first clamp diode Ds2, an absorption capacitance Cs, an absorption switching tube Qs, a current reverse irrigation preventing diode Df, a fly-wheel diode D, a filter inductance L, a drive resistance R and a protection diode Dp. The invention is mainly characterized in that the absorption switching tube Qs is driven by a bridge arm square wave through driving the drive resistance R; the output of the absorption circuit is connected with the output of a power. The invention can effectively absorb the voltage spike of the power switching tube, reduce the voltage stress, improve the efficiency of the converter, and has characteristics of comparatively simple structure and reliable performance.

In an embodiment, a power converter system is provided for AC voltage regulation. The power converter system receives an AC input voltage at an input terminal and provides an AC output voltage to a load at an output terminal. A main bi-directional switch is coupled between the input terminal and the output terminal. The main bi-directional switch is operable to control the provision of the AC output voltage. A reactive current flows through the main bi-directional switch if the load is reactive. An auxiliary bi-directional switch is coupled to the output terminal. The auxiliary bi-directional switch is operable to circulate the reactive current due to the reactive load, thereby reducing any voltage spikes in the power converter system.

A magnet controller supplied by an AC source controls a lifting magnet. Two bridges allow DC current to flow in both directions in the lifting magnet. During “Lift”, relatively high voltage is applied to the lifting magnet until it reaches its cold current. Then voltage is lowered. After a desired interval, once the magnet has had time to build its electromagnetic field, voltage is further reduced to prevent the magnet from overheating. The magnet lifting forced is maintained due to the magnetic circuit hysteresis. During “Drop”, reverse voltage is applied briefly to demagnetize the lifting magnet. At the end of the “Lift” and the “Drop”, most of the lifting magnet energy is returned to the line source. A logic controller controls current and voltage of the magnet and calculates the magnet's temperature. In one embodiment, a “Sweep” switch is provided to allow reduction of the magnet power to prevent attraction to the bottom or walls of magnetic rail cars or containers.

A semiconductor device includes a semiconductor substrate having a conductive type, a source metal layer, a gate metal layer, at least one transistor device, a heavily doped region having the conductive type, a capacitor dielectric layer, a conductive layer. The source metal layer and the gate metal layer are disposed on the semiconductor substrate. The transistor device is disposed in the semiconductor substrate under the source metal layer. The heavily doped region, the capacitor dielectric layer and the conductive layer constitute a capacitor structure, disposed under the gate metal layer, and the capacitor structure is electrically connected between a source and a drain of the transistor device.

For use in a power converter having parallel power trains, a circuit for, and method of, reducing voltage spikes due to magnetizing current imbalances in the power trains and a power converter incorporating the circuit or the method. In one embodiment, the circuit includes: (1) a conductive bypass path coupling nodes between transformer secondary windings and inductors in each of the power trains and configured to provide an alternative path to redirect magnetizing current imbalances from the inductors and (2) a capacitor located in the conductive bypass path.

The present invention is one kind of active shock-reducing circuit coupled to one synchronous rectifier, which has the first synchronous switching device and the second synchronous switching device and is coupled to one transformer of one power converter. The active shock-reducing circuit includes: one serial combination of one switch and one first shock-reducing capacitor and coupled to the first synchronous switching device, and one grid driver to make the switch on for one certain time during the non-conducting period of the first synchronous switching device. The grid driver includes one auxiliary coil, one capacitor connected to one end of the capacitor and one resistor, to which the serial branch of auxiliary coil and the capacitor is connected. The serial branch is also connected parallelly to the switch.

The invention relates to a driver based on a gallium nitride power device and a printed circuit layout. A resistor R2, a resistor R1, a variable impedance high-frequency suppressor, a voltage regulating diode and a spike absorption module are between the gallium nitride power transistor and a driving chip. The resistor R2 is connected in parallel to an output terminal of the resistor R2, a resistor R1 and a variable impedance high-frequency suppressor are connected in series are connected with a gate of a GaN power transistor de, and a voltage stabilizing diode is connected in parallel with the resistor R1 and the variable impedance high-frequency suppressor and is connected with an output terminal GND of the driving chip. The spike absorption module is connected in parallel to the drain and source of the output of the gallium nitride power transistor. The invention can ensure stable driving of the gallium nitride power device, reduce the number of components used in the driving circuit, reduce the cost of the driving circuit, restrain the gate driving oscillation of the gallium nitride power transistor under the high frequency operation, reduce the voltage spike in the switching process of the gallium nitride power transistor and other problems.

A snubber circuit for decreasing a voltage spike of a buck converter includes a resistor unit, a capacitor unit, a detecting unit, and a control unit. The resistor unit provides multiple groups of resistance values. The capacitor unit provides multiple groups of capacitance values. The detecting unit detects voltage spikes of the buck converter corresponding to each group of resistance values and capacitance values. The control unit selects each group of resistance and capacitance to respectively connect to the buck converter and determines a group of resistance and capacitance corresponding to a lowest voltage spike by comparing the detected voltage spikes with each other.

An inverter comprises a voltage regulation circuit, a multi-level bridge arm circuit and an output processing circuit, wherein the voltage regulation circuit receives DC input voltage, converts the DC input voltage into DC output voltage through voltage regulation, and outputs the DC output voltage to the multi-level bridge arm; the multi-level bridge arm circuit carries out chopping on the DC output voltage, and the DC output voltage is overlapped to AC to be outputted via the output processing circuit; the voltage regulation circuit comprises a voltage dividing circuit and a voltage regulation bridge arm; the voltage dividing circuit divides the DC input voltage into first voltage and second voltage; the voltage regulation bridge arm outputs the first voltage to the DC output end at a positive half cycle of AC output and outputs the second voltage to the DC output end at a negative half cycle of AC output; and the voltage at the DC output end is the DC output voltage. The technical scheme of the invention provides a simple and high-efficiency three-level interleaving topology structure which can be flexibly expanded to N-phase interleaving.

A power system, a power module therein and a method for fabricating power module are disclosed herein. The power module includes a first and a second common pins, and a first and a second bridge arms. The first and the second common pins are symmetrically disposed at one side of a substrate. The first bridge arm includes a first and a second semiconductor devices, and the first and the second semiconductor devices are connected to each other through the first common pin and disposed adjacently. The second bridge arm includes a third and a fourth semiconductor devices, and the third and the fourth semiconductor devices are connected to each other through the second common pin and disposed adjacently. The first and the third semiconductor devices are disposed symmetrically, and the second and the fourth semiconductor devices are disposed symmetrically.

The present invention relates to a three-level traction power module based on a SiC power device and an inverter circuit. An I-type three-level inverter bridge structure is adopted in an inverter maincircuit. The traction power module is successively integrated with a controller, a support capacitor module, a stack-layer bus-bar, a drive module, a SiC power module and a heat-dissipation piece from top to bottom. SiC-MOSFET(s) and SiC-DIODE power device(s) are adopted in the SiC power module. The drive module is connected with the SiC power module, and the controller is connected with the drive module to control the on-off state of the SiC power module. The support capacitor module is connected with the SiC power module, and the SiC power module is fixedly connected with the heat-dissipation piece. According to the module, the integrated and systematic design is adopted in the traction power module, the volume and the weight of the module are effectively reduced by using the high-frequency and high-temperature characteristics of the SiC power device, and all aspects of performances of the traction power module are greatly improved compared with the conventional power module based on Si device(s).

The invention discloses a drive circuit of a silicon carbide semiconductor field effect transistor. The drive circuit comprises a PWM control circuit, a drive signal amplification circuit, a turn-offcircuit, a gate shunt circuit and a current change rate control circuit, wherein the gate shunt circuit is switched on when the turn-off circuit works to perform shunt of the gate current of a SiC MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and accelerate the switch-off of the SiC MOSFET; the SiC MOSFET is switched off when the drain-source voltage of the SiC MOSFET is increased toa preset value; the current change rate control circuit is switched off when the drain-source voltage of the SiC MOSFET is increased to the preset value to reduce the leakage current change rate. Thegate shunt circuit is arranged to perform shunt of the gate output current in the SiC MOSFET switch-off process and speed up the decreasing speed of the gate-source voltage so as to improve the switch-off speed of the SiC MOSFET; and besides, in the switch-off process of the SiC MOSFET, the switch-off of the current change rate control circuit reduces the leakage current change rate so as to reduce the voltage peak when the SiC MOSFET is switched off, the two circuits cooperatively act to achieve the voltage reduction speed and the low-voltage peak of the high gate-source voltage and ensure the safety operation of the SiC MOSFET.

The invention discloses a wide-load-range zero-voltage-switching full-bridge transformer for effectively suppressing secondary-side voltage spikes. The wide-load-range zero-voltage-switching full-bridge transformer comprises a direct-current power supply, a first inverter bridge arm, a second inverter bridge arm, an auxiliary capacitor, an auxiliary inductor, a current conversion capacitor, an isolation transformer and a rectifying filtering circuit. According to the invention, a phase shift control manner is adopted, by means of additional arrangement of the current conversion capacitor and an LC (Inductive-Capacitive) auxiliary network, the voltage spikes and oscillations of an output rectifying diode are suppressed favorably, the zero-voltage switching of a switch tube in a wide load range can be realized, and meanwhile, the losses of secondary-side duty cycle are eliminated.

The invention discloses an intelligentized power module of a braking feedback converter. The intelligentized power module comprises a power unit arranged on a radiator and a control system, an air inlet is arranged on the lower portion of the radiator, an air outlet is arranged on the upper portion of the radiator, the power unit comprises three phase power components and a capacitance set which are used for connection of three phase alternating current power grid, the capacitance set is fixed on one side of the radiator vertical to the communication direction of the air inlet and the air outlet, the three phase power components of the power unit are fixed on the surface of the radiator in parallel, and the control system is mounted on one side of the three phase power components opposite to the radiator. The intelligentized power module of the braking feedback converter adopts modularized design, the control system is mounted on the surface of one side of the three phase power components opposite to the radiator, an IGBT (insulated gate bipolar transistor) driving component accesses to the power unit nearby, and the intelligentized power module of the braking feedback converter is strong in anti-interference capacity, compact in overall structure and high in power density. The modularized design can realize direct parallel connection and redundancy operation of multiple modules, and the normal operation of other modules do not be affected after a single module is cut.

The invention discloses a high-voltage transmission ratio bidirectional DC converter and a control method thereof. The high-voltage transmission ratio bidirectional DC converter mainly comprises a high-voltage side three-phase full-bridge consisting of six switch tubes, a Y-delta shaped three-phase transformer and a low-voltage side three-phase bridge arm consisting of three filtering inductors and three switch tubes. The invention also provides a control method of the high-voltage transmission ratio bidirectional DC converter. The internal characteristics and the control mode of the Y-delta shaped three-phase transformer are utilized to improve the voltage transformation ratio by one time in comparison with a traditional bidirectional DC converter, so that the turn ratio of the transformer is reduced by one time, and the leakage inductance is greatly reduced, the electromagnetism compatibility of the transformer is improved. The low-voltage side three-phase inductors are parallelly connected in a staggered manner, and the output current ripple is greatly reduced after the three-phase current ripples are stacked, so that the service life of a storage battery can be favorably prolonged, and the size of a filter is favorably reduced. The high voltage side and the low voltage side both adopt the three-phase staggered shunt-wound structure, so that the current stress of the switch tubes is reduced and suitable switch tubes can be conveniently selected for high-power application occasions.