367 results about "Stray inductance" patented technology

The present application discloses a laminated busbar arrangement for use in a three-level power converter and a power converter. The laminated busbar arrangement comprises a first layer of busbar comprising a neutral-point sub busbar congfigured to make electrical connections between respective components in the three-level power converter and a neutral-point potential; a second layer of busbar comprising a plurality of sub busbars congfigured to make electrical connections between the respective components in the three-level power converter and a positive direct current (DC) input, a negative DC input and an alternating current (AC) input/output in the three-level power converter, and between respective semiconductor switching components. The present application may effectively reduce stray inductance.

The invention discloses a system and a method for on-line detection of operating junction temperature of an IGBT module. Under an actually continuous on and off switching operate states of the IGBT module, changeable drive current and collector current generate induced voltage on stray inductance of the IGBT module; the induced voltage occurs twice voltage changes during turn-off, and the interval is recorded as the temperature-sensitive time which is closely related to the operating junction temperature of the IGBT module under a regular voltage and current turn-off condition. According to the system and the method, an IGBT test system is established to extract the temperature-sensitive time at different DC bus voltages, IGBT conducting currents and operating junction temperatures so as to establish an off-line reference database, voltage between a driving emitting electrode and a power emitting electrode of the IGBT module are monitored during the actual operation of an IGBT, and the temperature-sensitive time is extracted to calculate junction temperature on line. Compared with the conventional technology for monitoring the operating junction temperature of the IGBT, the method provided by the invention has higher real-time performance and integration.

The present invention relates to a method and a control system for driving a three-strand brushless, electronically commutated electric motor (2), wherein a line AC voltage (U_N) is rectified and fed via a slim DC link (8) with minimum DC link reactance as a DC link voltage (U_Z) to an inverter (10) that can be driven to supply and commutate the electric motor (2). A pulsating DC voltage (U_G) initially generated by rectifying the line AC voltage (U_N) is dynamically increased with respect to its instantaneous values by a step-up chopper (18) in such a manner that the resulting DC link voltage (U_Z) with a reduced ripple always lies above a defined limit voltage (U₁₈/U₁) over time. The control system consists of a network rectifier (6), a downstream slim DC link (8) with minimum DC link reactance and a controllable inverter (10) that can be supplied via the DC link and driven to commutate the electric motor (2). A step-up chopper (18) is integrated therein with a controller (20) designed in such a manner that, the pulsating DC voltage (U_G) rectified by the network rectifier (6) is dynamically increased with respect to its instantaneous values in such a manner that the resulting DC link voltage (U_Z) with a reduced ripple always lies above a defined limit voltage (U₂₀/U₁) over time. Stray inductances (Ls1-Ls3) of the motor winding heads present in the electric motor (2) are used as inductor (L) for the step-up chopper (18).

The invention provides a process for forming gallium nitride device and ground through-hole in circuit, which comprises the following steps including (a) coating polymeric substance on the surface of epitaxy material of heterojunction of gallium aluminum nitride/ gallium nitride, (b) installing the surface coated polymeric substance on a pressing disc, (c) ball milling, polishing and catching the surface 12 of an underlay, (d) coating a thickness of mask layer on the surface of the underlay, a trompil with precalculated position is arranged in the mask layer 23, (e) etching the underlay to obtain the through hole by employing jigger coupling plasmas of fluoride group gas, (f) reserving the mask layer, etching to form ground through-hole of the electrode by the jigger coupling plasmas of fluoride group gas and (g) removing the mask layer, metalizing the surface of the through-hole and underlay and finally realizing the ground connection of the electrode. The invention saves using ground lead, eradicates the unwilled stray inductance capable lead in micro frequency, further, the operation is simple, which is easy to realize in technique.

A power semiconductor module has four power terminals. An IGBT has a collector connected to the first power terminal and an emitter coupled to the third power terminal. An anti-parallel diode is coupled in parallel with the IGBT. A DC-link is connected between the second and fourth power terminals. The DC-link may involve two diodes and two IGBTs, where the IGBTs are connected in a common collector configuration. The first and second power terminals are disposed in a first line along one side of the module, and the third and fourth power terminals are disposed in a second line along the opposite side of the module. Two identical instances of the module can be interconnected together to form a three-level NPC phase leg having low stray inductances, where the phase leg has two parallel DC-links.

The invention discloses a circuit and a method for measuring stray inductance of a current conversion circuit of a three-level converter. The circuit comprises a first IGBT (insulated gate bipolar transistor), a second IGBT, a third IGBT, a fourth IBGT, a first clamp diode, a second clamp diode, a first resonant capacitor, a second resonant capacitor, a first direct-current support capacitor, a second direct-current support capacitor, a laminated busbar, a direct-current power supply and a freewheel reactor. The method includes forming different freewheel circuits by the freewheel reactor; exerting double pulses to each corresponding IGBT; taking an average value of resonance current frequencies at a turn-on moment and a turn-off moment; and precisely computing the stray inductance of the current conversion circuit by an LC parallel resonance characteristic realized by the resonant capacitors and the stray inductance of the circuit. The circuit and the method have the advantages that actual operation is facilitated, the stray inductance of the current conversion circuit of the three-level converter can be accurately measured, overvoltage levels of a power device under different current grades of the three-level converter can be accurately controlled conveniently, and accordingly establishment of a system control strategy can be guided.

The invention provides a composite busbar and a three-phase inverter circuit. The composite busbar comprises busbar units, terminals and connection portions. The busbar units are flat, at least two busbar units are overlapped, and the position between the adjacent busbar units is filled with high-insulating-strength materials, so that the adjacent busbar units are insulated. The terminals are arranged on the busbar units and used for being connected with circuit devices, and the connection portions are arranged on the busbar units and used for being connected with direct-current input ends or the circuit devices. The composite busbar is used for solving the problem that in the prior art, a circuit is large in stray inductance, reduces the stray inductance of the circuit, and reduces peak voltage.

The invention relates to an integrated gate commutated thyristor (IGCT) three-level power module belonging to the technical field of high-power semiconductor switches. The IGCT three-level power module comprises an IGCT, an antiparallel flywheel diode, a left metal frame weld assembly, a right metal frame weld assembly, a pressing mechanism, a square water-cooling radiator, an insulating fixed pin, an insulating draw rod, an insulating hook pin, a P phase leading-in bus bar, a P phase leading-out bus bar, an M phase leading-out bus bar, an N phase leading-out bus bar, an N phase leading-in bus bar and the like. The invention adopts a structural style of three mutually parallel power strings, and each power string realizes the compression joint of electric/electronic components with the corresponding connecting bus bars, the square water-cooling radiator and insulators by the pressing mechanism. In the invention, absorption circuits are compactly arranged, thereby decreasing the mutual stray inductance; and a waterway interface and a power circuit interface are separated and are arranged respectively in the front and at the back.

The invention relates to a measurement device for stray inductance in an IGBT module. The measurement device is characterized in that the measurement device comprises a power supply device, a to-be-measured IGBT module, a current probe, a voltage probe, an oscilloscope, a pulse triggering device, controllable switches S1, S2, S3, a DC capacitor C1, a DC discharging resistor R1, a load inductor L1 and a freewheeling diode D1; the controllable switch S2 is serially connected with the DC discharging resistor R1 and is parallelly connected with the DC capacitor C1; the freewheeling diode D1, the controllable switch S3 and the to-be-measured IGBT module are serially connected; the pulse triggering device is connected with the controllable switch S3; and the load inductor L1 is parallelly connected with two sides of the freewheeling diode D1. The measurement device can effectively evaluate induction voltage of an inner packaging parasitic parameter when the IGBT module is in a switching-off transient state. The packaged stray inductance which is calculated according to the voltage and current over two ends of a parasitic inductor is more practical and can be used for evaluating an IGBT safety margin, and furthermore can be used for verifying IGBT module designing. The measurement device and the measurement method have a certain meaning to semiconductor manufacturers and IGBT application parties.

The invention provides a phase module for a three-level integrated gate-commutated thyristor frequency converter, comprising the structure that two strings of same eudipleural crimping devices are arranged in a framework, wherein each string of crimping devices are same and comprise six heat radiators; a first integrated gate-commutated thyristor (IGCT), a first free-wheeling diode, a second free-wheeling diode, a second IGCT and a clamping diode are sequentially connected among the six heat radiators; same devices on two sides of absorbing circuits at the rear parts of the two strings of crimping devices are symmetrically arranged; a clamping capacitor and an absorbing resistor which are vertically arranged are arranged on each side of the absorbing circuits; absorbing diodes are horizontally arranged above the clamping capacitor and the absorbing resistor; and conductive bus bars are respectively arranged on two sides of the framework and are eudipleural with respect to the framework. By using the phase module, the devices of the frequency converters are divided into two same strings, are eudipleural and are vertically distributed in the framework, so that the connecting line distance among various devices can be reduced. In addition, the line outlet positions are eudipleural, thus the stray inductance of the whole circuit can be greatly reduced.

An optical transceiver module is constituted so as to have an optical transmission module, an optical receiving module, a drive circuit board for driving the optical transmission module and the optical receiving module, and short-circuit means which induces an electrical short circuit between housings of the respective modules or induces an electrical short circuit between ground (GND) terminals of the respective modules on the module sides with respect to the drive circuit board. As a result, in the optical transceiver module, stray capacitance and stray inductance in lead pins, housings, and internal components of optical devices, such as an LD and a PD, are removed, thereby suppressing fluctuations in the potential (GND) of an LD housing which arise during high-frequency driving operation, as well as considerably suppressing electrical crosstalk between the transmission and receiving modules.

The invention discloses a bidirectional-resonance bridge type modular multi-level switched capacitor DC-AC converter which sufficiently uses stray inductance of circuits to serve as resonance oscillation and can achieve level extension easily through an extension switched capacitor module. Bidirectional energy flow between the high voltage side and the lower voltage side and regulation of output voltage are achieved through phase-shifting control of a switch tube. In the boosting state, the bidirectional-resonance bridge type modular multi-level switched capacitor DC-AC converter can output input voltage of 2-4 times; in the depressurization state, the bidirectional-resonance bridge type modular multi-level switched capacitor DC-AC converter can output input voltage of 0-0.5 time. The bidirectional-resonance bridge type modular multi-level switched capacitor DC-AC converter is simple in control, solves the problems that output voltage of the traditional switched capacitor is difficult to regulate, bidirectional energy flow is hard to control and peak currents of the working circuits are large, and improves efficiency and power density of the converter; is mainly applied to occasions where bidirectional energy flow, high efficiency and large power are required, such as micro-grid and electromobile motor drive.

The invention discloses a high-voltage high-capacity impulse voltage generator. The impulse voltage generator comprises a charging capacitor, a wave head resistance, a wave tail resistance, a voltage divider, a load and a sphere gap; the impulse voltage generator is provided with a plurality of impulse voltage generating units consisting of the charging capacitor, the wave head resistor and the wave tail resistor; and the wave head resistor is arranged in a discharging loop. The impulse voltage generator is characterized in that: in partial or all impulse voltage generating units, wave modulation capacitors are arranged in parallel at two ends of the wave head resistor. The generator overcomes the defect that the wave modulation resistor of the traditional method cannot generate standard thunder impulse, can effectively inhibit adverse effect generated by stray inductance, and generates standard thunder impulse voltage; and the generator can generate the standard thunder impulse by increasing a few elements based on the conventional equipment, and has the advantages of small volume, low cost and the like.

A minimalized power converter has a square-wave voltage source operating at 100 percent duty-ratio, a series inductance and a rectifier. A high frequency square-wave power distribution system comprises a plurality of minimalized power converters connected by a common ac power distribution link. Because the ac power distribution link carries current at a high frequency, the square-wave may be degraded by the stray inductance with distance. Re-squaring circuits along the length of the ac power distribution link operating synchronously restore and preserve the integrity of the square-wave. The minimalized power converter is very flexible and has very fast dynamic response, being able to make very fast controlled current transitions from any current to any other current, including zero or current reversal (same voltage, opposite current flow).

A flat type wide frequency sensor for a power transmission project comprises a GIS casing 1, a cavity mask 24, a pole plate 3, an insulation film 2, a connector 5, a plug 11, a tray 15 and matched resistors 14, wherein the cavity mask 24 is arranged at the opening of the GIS casing 1, the pole plate 3 adheres to the cavity mask 24 with the in-between insulation film 2, the pole plate 3 is electrically connected with the masking type plug 11 through the insulated connector 5, the plug 11 is fixed on the cavity mask 24, the tray 15 which is fixed in the inner cavity of the cavity mask 24 is arranged between the connector 5 and the plug 11, the axle center of the plug 11 is positioned at the circular center of the tray 15, and a plurality of paralleled matched resistors 14 are evenly distributed along the circumference of the tray 15. The flat type wide frequency sensor is a practical quick steep-wave sensor integrating a capacitance sensor, the measurement system matched resistors, a signal masking protective function and an inserting piece for connecting a measurement cable. Furthermore, a plurality of paralleled matched resistors are evenly distributed in the sensor, thereby bringing about the little stray inductance of a measurement system, little wave form distortion and wide measurement frequency domain. The flat type wide frequency sensor is applicable to the VFTO measurement in the GIS or H-GIS.

The invention discloses a laminated busbar used for a diode clamp type three-level converter. The laminated busbar used for the diode clamp type three-level converter comprises a module busbar and a direct current capacitor busbar which are mutually connected. The module busbar is divided into five layers, the first layer comprises an alternating current outlet busbar, a module positive busbar and a module negative busbar; the second layer is an insulation layer; the third later is a module zero busbar; the fourth layer is an insulation layer; and the fifth layer comprises a first module connection busbar and a second module connection busbar. The direct current capacitor busbar is divided into five layers, the first layer is a capacitor positive busbar; the second layer is an insulation layer; the third later is a capacitor zero busbar; the fourth layer is an insulation layer; and the fifth layer is a capacitor negative busbar. The laminated busbar used for the diode clamp type three-level converter can reduce stray inductance of a commutation circuit greatly, turn-off overvoltage of devices can be effectively restrained, a du/dt adsorption circuit is eliminated, and the structure is compact while cost is reduced.

An inductive power transfer circuit or inductive rotary joint has an inductive rotating coupler with a primary side and a primary winding rotatably arranged against a secondary side and a secondary winding. The secondary side is connected via a rectifier to a load. The stray inductance of the coupler together with a resonance capacitor a series resonance circuit having a series resonance frequency. An inverter in a full bridge circuit is provided for converting a DC input voltage into an AC voltage. The inverter is operable in a full bridge mode to deliver a high power level and in a half bridge mode to deliver a low power level. This results in a broad dynamic range, soft power on and improved safety, as switching between the modes may be controlled by a simple hardware.

The invention provides a high-capacity water-cooling power unit, which comprises a power module and a capacitor assembly, wherein the power module is symmetrically placed and arranged on the basis of single-tube IGBTs; two single-tube IGBTs corresponding to an upper bridge arm and a lower bridge arm of the power module are arranged in a mirror symmetry manner; a drive control part of the single-tube IGBT of the upper bridge arm and the drive control part of the single-tube IGBT of the lower bridge arm are placed outwards; and a single-tube IGBT symmetry layout mode is adopted by the power module, so that large-area lamination of IGBT laminating busbars is facilitated; stray inductance of a loop is reduced; the working reliability of a switching device is improved; an alternating-current busbar is led out through a bridging copper bar via an opening; the influence to a direct current busbar loop is reduced; heat dissipation is facilitated; and the reliability of a system is improved.

The invention discloses the pulse test circuit and the method of a flying capacitor three-level DCDC power component. The test circuit comprises a three-level power module, an adjustable direct current source, a discharge branch and a freewheeling inductor. The three-level power module comprises a supporting capacitor, a flying capacitor, an absorbing capacitor, and first to fourth IGBTs which areconnected in series. Each IGBT is connected with a voltage equalizing resistor and a reverse freewheeling diode in parallel. The adjustable direct current source and the discharge branch are connected in parallel with the supporting capacitor, the absorbing capacitor and a switching conversion circuit. When the three-level power module is operated in a Buck work mode, the freewheeling inductor isconnected between the third IGBT and the fourth IGBT in parallel. When the three-level power module is operated in a Boost work mode, the freewheeling inductor is connected between the first IGBT andthe second IGBT which are connected in series in parallel. In the invention, through controlling different switch conversion modes, each IGBT is subjected to a turn-on-turn-off-turn-on-turn-off process, and the ability of the power component to bear overcurrent and turn-on and turn-off characteristics are examined. The stray inductance of a converter circuit and a caused overvoltage condition areanalyzed and a system design is improved.

The invention discloses a method for extracting stray parameters of a laminated bus bar based on frequency characteristics of a SiC MOSFET. The method comprises the following steps of firstly settingup a SiC MOSFET double-pulse test platform, and externally connecting the section under test of the laminated bus bar to the test platform; connecting multiple sets of additional capacitors in parallel at both ends of the SiC MOSFET, using the frequency information of oscillation in the off-voltage waveform of the SiC MOSFET before and after the additional capacitors are connected in parallel to obtain the resonance angular frequencies of multiple sets of equivalent circuit models, and further calculating the stray inductance and parasitic capacitance of the laminated bus bar to achieve the extraction of stray parameters of the laminated bus bar. The invention utilizes the high switching speed characteristics of the SiC MOSFET to excite obvious off-voltage oscillations. Compared with the traditional indirect measurement method, the measurement deviation caused by human factors is reduced. In addition, the invention can measure the stray inductance and parasitic capacitance in any section of the laminated bus bar, and the measurement is more flexible and comprehensive.

Disclosed is a protection circuit for protecting a rectifier circuit from electrostatic pulses. The circuit employs a first bypass capacitor that is connected between positive and negative power lines to bypass electrostatic pulses that have a rise time that allows the diodes to conduct and prevent damage to the diodes as a result of reverse biasing, and a second bypass capacitor that is connected between an input node and the negative power line to discharge the electrostatic pulses that have a rise time that is faster than the turn-on times of the diodes. Connection of the bypass capacitors at locations close to the rectifying diodes minimizes the effects of stray inductance that affects the operation of the rectifier circuit in response to fast rise time transient pulses.

The invention provides an IGBT switch instant surge suppression apparatus and method for a PWM current converting system. The method comprises the following steps: a total stray inductance value LTotal of the PWM current converting system in a stray inductance extraction time slot t1-t2 is obtained, an IGBT equivalent circuit model is built based on the total stray inductance value LTotal and characteristics of the PWM current converting system, the IGBT equivalent circuit model comprises a non-inductive absorbing thin film capacitor CSnubber used for suppressing IGBT switch instant surges, a direct current bus stray inductance value LDC-Link of the PWM current converting system is obtained based on the IGBT equivalent circuit model, a capacitance value of the non-inductive absorbing thin film capacitor CSnubber is obtained based on the direct current bus stray inductance value LDC-Link, an IGBT surge voltage change preset value [delta]V2 and an IGBT work current IC, and the IGBT switch instant surges can be suppressed via the non-inductive absorbing thin film capacitor CSnubber. The IGBT switch instant surge suppression apparatus and method for the PWM current converting system can be used for effectively suppressing the IGBT switch instant surges.

The invention discloses a power module with lower stray inductance. The power module comprises a chip, an insulating substrate, a radiating rib and power terminals, wherein the insulating substrate is positioned on the radiating rib; the chip is welded on the insulating substrate; at least two power terminals are arranged in the module and are connected to the positive electrode and the negative electrode of a direct current bus respectively; and the two power terminals connected to the direct current bus are of a stacked bus structure. The power module has the characteristics of small stray inductance, small voltage stress endured when the module is turned off.