186 results about "Forward current" patented technology

A method protects against fault arcs in an electric power distribution system in which electric power from an electric feed point is distributed via a common superordinate main distribution line and from the common main distribution line via multiple subordinate output lines. The main distribution line can be interrupted by a main switch, and each of the output lines can be interrupted by a paired output switch. A fault arc current threshold which, when exceeded by a fault arc current of a fault arc, is a precondition for triggering the main switch is matched to the maximum forward current and / or the output trigger duration of the output switches such that a fault arc is quenched selectively either by one of the output switches or by the main switch before the energy released by the fault arc exceeds a specified energy threshold.

Unidirectional hybrid switch. At least one example is a method operating a hybrid switch, the method comprising: sensing a voltage across an upper terminal and a lower terminal of the hybrid switch, the hybrid switch is forward biased when the upper terminal has higher voltage, and the hybrid switch is reverse biased when the lower terminal has higher voltage; when the hybrid switch is forward biased, selectively conducting a forward current from the upper terminal to the lower terminal by sharing the forward current between a FET switch and a BJT switch, the selectively conducting when a control terminal is asserted; and when the hybrid switch is reversed biased, non-selectively conducting a reverse current from the lower terminal to the upper terminal.

The invention discloses a Ga2O3 SBD trap test method based on forward current transient response, and belongs to the field of semiconductor device reliability. Comprising the following steps: giving a filling voltage interval and a filling time interval of a Ga2O3 SBD trap filling stage; giving a bias condition and a test time interval of a trap test stage; giving a normalization processing method and range of the forward current transient response; a characterization range of a Ga2O3 SBD device level trap time constant is given. The transient response curve of the forward current of the Ga2O3SBD under the constant test voltage is collected, and the transient current variation caused by the trap is evaluated through a normalization processing method. And repeatedly testing under the condition of multiple groups of filling voltages, establishing a time constant spectrum of the trap by using a structure function method, and extracting a time constant parameter of the trap in the Ga2O3SBD to realize in-situ and online Ga2O3SBD trap test. The method is suitable for evaluating the trap effect of Ga2O3 SBD devices from different manufacturers, and can realize spectral valuation characterization of Ga2O3 SBD traps and in-situ and nondestructive testing of trap parameters.

In an MMC-type power conversion device, a control device calculates an evaluation value representing the degree of variations in voltage of capacitors of individual converter cells. When this evaluation value exceeds a threshold value, the control device controls the converter cells as follows: (i) when current in a positive direction flows through a first converter cell with a voltage of the capacitor greater than a mean value, reducing an output time of positive voltage, (ii) when current in a negative direction flows through the first converter cell, increasing an output time of positive voltage, (iii) when current in the positive direction flows through a second converter cell with a voltage of the capacitor smaller than a mean value, increasing an output time of positive voltage, or (iv) when current in the negative direction flows through the second converter cell, reducing an output time of positive voltage.

The invention discloses a micro-copper pillar bump interconnection resistor electromigration degradation prediction method. The method comprises the following steps: obtaining the net flux of Cu atoms in a Cu6Sn5 layer and a Cu3Sn layer and the net flux of Ni atoms in a Ni-Cu-Sn compound layer under forward current and reverse current; establishing a relationship between the net flux of Ni atoms and the thickness change of the Ni-Cu-Sn compound layer and a relationship between the net flux of Cu atoms and the thickness change of the Cu6Sn5 layer and the Cu3Sn layer; establishing a thickness polarity growth model of the Ni-Cu-Sn compound, the Cu6Sn5 layer and the Cu3Sn layer; establishing a thickness polarity consumption model of the Cu bonding pad, the Sn solder and the Ni layer; and establishing a resistance electromigration degradation model of micro-copper pillar bump interconnection. According to the method, the electromigration degradation prediction of the interconnection resistor of the copper pillar bump plated with the Ni layer can be realized, and a large amount of service life and time and economic cost generated by a failure analysis test are greatly reduced or avoided.

The invention discloses a method for measuring and analyzing residual magnetism characteristics of an iron core. According to the method, a to-be-detected iron core is demagnetized, preset residual magnetism is set, direct-current voltage excitation with opposite polarities, the same amplitude and the same duration is applied to a primary winding of the to-be-detected iron core, and transient current response signals are synchronously collected; two groups of current under positive / negative polarity excitation are extracted, and the residual magnetism direction is judged by comparing the change rate of the current; a curve of equivalent resistance changing along with time is calculated based on forward current and voltage, a resistance value corresponding to a characteristic inflection point moment is selected, the resistance value is substituted into a pre-established residual magnetism-equivalent resistance empirical formula to deduce the magnitude of residual magnetism, and a matched iron core residual magnetism detection and demagnetization integrated system integrates information management, residual magnetism detection, demagnetization and display modules. And closed-loop automation of detection, analysis and demagnetization is realized. According to the method, a magnetic field sensor is not needed, the residual magnetism direction and size can be synchronously obtained in a high-precision and robust mode only through port electric signals, and the method is suitable for on-site off-line or live detection.

The invention discloses an energy consumption type pulse special power supply topology circuit, particularly relates to the technical field of power supply circuits, and is technically characterized in that a forward energy storage unit is used for outputting forward current to an external load coil and providing energy required by main compression for a field inversion configuration device; the negative energy storage unit is used for outputting negative current to an external load coil and providing bias field energy for the field inversion configuration device; the charging unit is also used for charging the current source unit; the current source unit is used for providing bias current for an external load coil and creating a bias condition for the field inversion configuration device; the resonance unit is used for outputting resonance current to an external load coil and providing energy required by pre-ionization for the field inversion configuration device; the first consumption unit is used for consuming residual electric energy after the external load coil and the current source unit work; the first control unit is used for controlling short circuit of the first consumption unit; the second control unit is used for controlling the on-off of the resonance unit; and the third control unit is used for controlling the on-off of the negative energy storage unit.

A non-isolated bidirectional high-voltage direct current battery charger is made compatible with a ground-fault circuit interrupter (GFCI) at the DC output by adapting the power converter to control, in response to voltage or current sensors, a net current difference between forward current and return current to remain below a threshold of the GFCI. This can be done without compromising safety in the case of actual ground faults.

A non-isolated bidirectional high-voltage direct current battery charger is made compatible with a ground-fault circuit interrupter (GFCI) at the DC output by adapting the power converter to control, in response to voltage or current sensors, a net current difference between forward current and return current to remain below a threshold of the GFCI. This can be done without compromising safety in the case of actual ground faults.

Back-surface roughness of a back surface of a silicon carbide semiconductor device having a MOS gate structure in a first region that is a region within 30 μm of a cross section (lateral surface) of the device is at most 4 μm while the back-surface roughness in a second region other than the first region is at most 2 μm, the back surface of the silicon carbide semiconductor device is the back surface of the second electrode. In a method of manufacture, the back-surface roughness of the device is specified to meet a predetermined condition. Then, ON voltages of the device before and after a forward current is passed through body diodes of the device are measured, and a rate of change of the ON voltage while the forward current is passed through body diodes is calculated, and then the device having a calculated rate of change less than 3% is identified.

The invention discloses an energy feedback type pulse special power supply topology circuit, particularly relates to the technical field of power supply circuits, and is technically characterized in that a forward energy storage unit is used for outputting forward current to an external load coil and providing energy required by main compression for a field inversion configuration device; the current source unit is used for receiving and storing electric energy, providing bias current for an external load coil and creating bias conditions for the field inversion configuration device; the negative energy storage unit is used for outputting negative current to an external load coil and providing bias field energy for the field inversion configuration device; the charging unit is also used for charging the current source unit; the resonance unit is used for outputting resonance current to an external load coil and providing energy required by pre-ionization for the field inversion configuration device; the first bidirectional combination switch is used for controlling the on-off of the resonance unit; and the second bidirectional combination switch and the third bidirectional combination switch are used for controlling the positive on-off and negative on-off of the circuit.

The invention relates to the technical field of solar cells, in particular to a battery piece grading method. The battery piece grading method comprises the following steps: providing a photovoltaic module made of battery pieces at the same grade as to-be-graded battery pieces; obtaining a forward current of the photovoltaic module; according to the series resistance and the open-circuit voltage of the to-be-graded battery piece and the forward current of the photovoltaic module, the equivalent luminous power of the to-be-graded battery piece is obtained; and grading the to-be-graded battery pieces according to the equivalent luminous power of the to-be-graded battery pieces. According to the grading method of the battery pieces, the EL light and shade consistency of the photovoltaic module formed by the battery pieces which are graded by taking the equivalent luminous power of the battery pieces as the index is greatly improved.

A temperature sensor device is capable of measuring minute temperature changes while being manufactured at low cost without needing a high performance IC tester. A temperature sensor device includes a temperature sensor circuit 2 and a temperature sensor 1. The temperature sensor 1 includes a PN junction element 15 which is a temperature sensing element, a variable current source which supplies different forward currents of at least two values to the PN junction element 15 and a constant voltage source 16 which outputs a constant voltage having the same temperature properties as a forward voltage of the PN junction element 15.

The invention relates to the technical field of measurement of long-distance and high-accuracy temperature measurement resistors, and particularly discloses a resistor temperature measurement method, which comprises a constant current source I, temperature measurement resistors RX and RY, a reference resistor RR, an analog switch, an instrument amplifier, an analog-to-digital converter and a microcontroller, the method comprises the following specific steps that S1, an analog switch controls a constant current source I to sequentially flow through temperature measurement resistors RX and RY and a reference resistor RR, and current generates a voltage on each resistor and is in direct proportion to the resistance value of the voltage; and S2, measuring the voltages of the temperature measuring resistors RX and RY and the reference resistor RR through an instrument amplifier and an analog-to-digital converter to obtain VX1, the voltage of the temperature measuring resistor RX under the forward current condition, VY1, the voltage of the temperature measuring resistor RY under the forward current condition, and VR1, the voltage of the temperature measuring resistor RR under the forward current condition. According to the resistance temperature measurement method, 0.00025 DEG C or better uncertainty can be obtained, and observable errors caused by thermoelectromotive force can be effectively eliminated.

The application discloses a relay, and belongs to the technical field of electric appliance switches. The relay comprises a first shell, an electromagnetic structure, a moving contact structure and a stationary contact. The electromagnetic structure and the stationary contact are both fixed in the first shell. The electromagnetic structure is provided with two first magnetic parts which are spaced apart along a first direction. The moving contact structure is slidably arranged in the first shell along a second direction. The moving contact structure comprises a moving contact, a first moving magnetic part and a second moving magnetic part which are sequentially and spaced apart along the second direction. The magnetic poles of the first moving magnetic part and the second moving magnetic part are opposite. When a forward current is input into the electromagnetic structure, the two first magnetic parts are both attracted to the first moving magnetic part, and the moving contact and the stationary contact are separated. When a reverse current is input into the electromagnetic structure, the two first magnetic parts are both attracted to the second moving magnetic part, and the moving contact and the stationary contact are in contact. The relay provided by the application is beneficial to increasing the opening distance between the moving contact and the stationary contact, and reducing the risk of electric leakage from the moving contact and the stationary contact to the electromagnetic structure.

The invention provides a semiconductor structure which comprises a substrate and a multi-channel heterojunction layer which are arranged in a stacked mode, the multi-channel heterojunction layer comprises a plurality of heterojunction layers, each heterojunction layer comprises a channel layer and a barrier layer, and the multi-channel heterojunction layer is provided with a plurality of grooves; and the P-type epitaxial layer comprises a plurality of first P-type regions for filling the grooves. The transverse PN junction is formed through the first P-type region and the two-dimensional electron gas in the heterojunction, the depletion region of the PN junction is broadened during reverse biasing so as to pinch off a current channel, the Schottky junction with low barrier height is effectively shielded, the Schottky barrier lowering effect can be inhibited, reverse leakage current can be controlled, and therefore the breakdown voltage is improved, and the low turn-on voltage is kept. And meanwhile, a plurality of parallel two-dimensional electron gas passages are formed between the cathode and the anode by utilizing stacking of a plurality of heterojunctions, so that depletion of two-dimensional electron gas by the first P-type region is compensated, and the forward current of the diode is ensured.

The utility model relates to the technical field of medical equipment, and particularly discloses a bipolar nanosecond pulse synchronous output circuit and ablation equipment, which comprise a positive pulse output circuit and a negative pulse output circuit, the positive pulse output circuit comprises a positive pulse charging unit, a positive pulse output control unit, a positive pulse transmission unit and a positive pulse output electrode wire which are electrically connected in sequence; the negative pulse output circuit comprises a negative pulse charging unit, a negative pulse output control unit, a negative pulse transmission unit and a negative pulse output electrode wire which are electrically connected in sequence; the positive pulse transmission unit at least comprises a forward multiplication transmission unit which is used for performing forward voltage multiplication or forward current multiplication on the forward output pulse signal; the negative pulse transmission unit at least comprises a negative multiplication transmission unit which is used for carrying out negative voltage multiplication or negative current multiplication on the negative output pulse signal. The bipolar nanosecond pulse synchronous output circuit provided by the utility model can improve instant pulse energy of nanosecond pulse tumor ablation equipment.

The invention relates to the technical field of solar photovoltaic modules, and particularly discloses a process method for passivating and contacting an auxiliary battery at a module end. The process method comprises the following steps: after battery pieces are subjected to series welding, lamination and packaging to form a battery assembly, the battery assembly is placed in an environment box for illumination, the temperature is set to be 50-75 DEG C, the irradiance is 1000-1500 Wh / m < 2 >, the forward current is 2-5 A, and illumination is carried out for 1-4 h. Under the conditions of high irradiance, medium temperature and low current, the battery piece adopting the LECO technology has a good internal defect repairing effect, contact between a metal electrode and silicon can be optimized again, the FF value and the Voc value of the battery assembly are improved, and therefore the power of the battery assembly is remarkably increased; and the contact resistance and passivation effect can be optimized at the component end in an auxiliary manner, so that the component power is improved, novel equipment does not need to be added on a production line, and the production efficiency is not influenced.

A moving core has a moving core main member made of soft magnetic materials and a permanent magnet member made of hard magnetic materials. A direction of the magnetic pole of the permanent magnet member matches that of a coil when the coil is positively energized with the forward current, and a stator core is non-existent in a range of movement of the permanent magnet member. Since there is the non-existent portion of the stator core in the range of movement of the permanent magnet member, it is possible to prevent generation of a magnetic flux loop of the magnetic field of the permanent magnet and it is possible to prevent a reduction of the attractive force.

The present application relates to the field of device fault diagnosis, and provides a device fault diagnosis method, system and equipment based on phase current and zero sequence voltage, comprising calculating phase current steady-state value and phase current fault transient value, and constructing single-phase open circuit fault flag; when the single-phase open circuit fault flag indicates that there is single-phase open circuit fault, obtaining fault phase flag quantity through phase current intensity coefficient; constructing first inverter fault flag through zero sequence voltage, when the first inverter fault flag indicates that there is fault, constructing second inverter fault flag through phase current unit value, obtaining inverter fault flag through the first inverter fault flag and the second inverter fault flag, determining device positioning threshold, constructing inverter fault positioning flag based on the device positioning threshold, positive current intensity and negative current intensity; obtaining final fault positioning flag, thereby diagnosing device fault of the device.

The application discloses a three-phase voltage source inverter, which comprises: inverter A, B and C three-phase upper and lower working bridge arms V a1 、 b1 、 c1 、 a2 、 b2 、 c2 , corresponding anti-association diodes VD a1 、 b1 、 c1 、 a2 、 b2 、 c2 , upper and lower bridge arm shunt switch devices S1 and S2, three-phase selective switch devices T a1 、 b1 、 c1 、 a2 、 b2 、 c2 in additional dynamic shunt branches; when the inverter AC side three-phase current has a phase with a maximum positive current, the T a2 、 b2 、 c2 corresponding to the additional dynamic shunt branch are turned on, and the S1 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum positive current; when a phase with a maximum reverse current exists, the T a1 、 b1 、 c1 corresponding to the additional dynamic shunt branch are turned on, and the S1 of the additional dynamic shunt branch is shunted in parallel to the phase with the maximum reverse current. The application reduces the overcurrent of the inverter working bridge arm switch device caused by AC system disturbance, and improves the operation reliability of the inverter.

The application discloses a low-cost heat-enhanced gallium nitride Schottky barrier diode and a preparation method thereof. The diode comprises a transmission layer, a drift layer arranged on the lower surface of the transmission layer, a positive electrode arranged on the middle area of the lower surface of the drift layer, a negative electrode arranged on the middle area of the upper surface of the transmission layer, a first dielectric layer arranged on the lower surface of the remaining drift layer and the sidewall and part of the lower surface of the positive electrode, a second dielectric layer arranged on the upper surface of the remaining transmission layer and the sidewall and part of the upper surface of the negative electrode, a part of a positive electrode thickening layer arranged on the lower surface of the first dielectric layer and the lower surface of the remaining negative electrode, another part of the positive electrode thickening layer exposed to the first dielectric layer, a heat dissipation substrate arranged on the lower surface of the positive electrode thickening layer and a negative electrode thickening layer arranged on the upper surface of part of the second dielectric layer and the upper surface of the remaining negative electrode. The application realizes a full-vertical gallium nitride Schottky barrier diode with greater forward current and higher heat dissipation capacity.

The invention belongs to the technical field of integrated circuits, and particularly relates to an ESD electrostatic protection structure suitable for a low-voltage circuit. The ESD electrostatic protection structure adopts a mode that an NPN triode with a floating layered base region structure is used for assisting in triggering an SCR to discharge forward ESD current and a PN junction diode to discharge negative ESD current; the NPN triode with the floating layered base region structure comprises an N + active region I, a P-type ESD injection region, a P well I and an N + active region II, the first N + active region and the second N + active region are a collector region and an emitter region of the NPN triode respectively, the base region is composed of a P-type ESD injection region and a first P well, the P-type ESD injection region is located below the first N + active region, and the base region is of a floating layered structure. The ESD protection structure is provided with a bidirectional rapid ESD current discharge path to the ground, so that the SCR trigger voltage is reduced.

The invention relates to the technical field of IGBT (Insulated Gate Bipolar Translator) structures, and discloses a soft-recoverable IGBT structure, which comprises an MOS (Metal Oxide Semiconductor) gate structure positioned on the front surface of a device, a diode anode structure, an n drift layer for bearing the withstand voltage of the device, and a field stop layer positioned below the n drift layer and used for optimizing an internal electric field of the device, a gradually-doped n-type adjusting layer, an IGBT part, a diode part, a p-type collector region and an n-type cathode region are arranged between the n drift layer and the field stop layer, the IGBT part and the diode part are arranged in anti-parallel, the p-type collector region is located on the back surface of the device and serves as the IGBT part, and the n-type cathode region is located on the back surface of the device and serves as the diode part. By introducing the n-type adjusting layer, excellent soft recovery characteristic and dynamic robustness are realized, low overall loss is maintained, and the device has strong recovery capability under extreme conditions (high VCC, high forward current and high temperature). And the tradeoff and tradeoff triangular relationship limitation among the traditional total loss, reverse recovery softness and diode (FWD) recovery safety working area is broken through.

Examples described herein provide a method that includes, responsive to determining that a direction of a current relative to a power source of a vehicle is a forward current flowing out of the power source, determining whether the forward current exceeds a forward current threshold for a forward overcurrent detection time period by comparing the current to the forward current threshold. The method further includes, responsive to determining that the direction of the current relative to the power source is a reverse current flowing into the power source, determining whether the reverse current exceeds a reverse current threshold for a reverse overcurrent detection time period shorter than the forward overcurrent detection time period by comparing the current to the reverse current threshold. The method further includes controlling, using a gate driver, at least one switch associated with the power source to inhibit the current.

The examples described here provide a method which, in response to the determination that the direction of a current with respect to a vehicle power source is a forward current flowing out of the power source, includes determining whether the forward current exceeds a forward current threshold during a forward overcurrent detection period by comparing the current to the forward current threshold. The method further includes, in response to the determination that the direction of the current with respect to the power source is a reverse current flowing into the power source, determining whether the reverse current exceeds a reverse current threshold during a reverse overcurrent detection period that is shorter than the forward overcurrent detection period by comparing the current to the reverse current threshold.The method further includes controlling at least one switch associated with the power source using a gate driver to block the current.

The invention belongs to the technical field of semiconductor devices, and provides a bidirectional current response differential film resistor and a preparation method thereof. The oxide layer is arranged on the N-type silicon substrate; the first window is formed in the oxide layer; the P-type doped region is formed by injecting P-type ions into the first window; the film layer comprises a first resistor and a second resistor which are arranged at intervals and have different resistance values; the passivation layer is arranged on the oxide layer and the thin film layer; the second window is formed in the passivation layer and corresponds to the first window B; the N-type doped region is formed by injecting N-type ions into the second window; the third window is formed in the passivation layer; a first electrode, a second electrode, a first test PAD and a second test PAD are respectively formed on the front metal layer. According to the thin-film resistor provided by the invention, when forward current passes through a device, one resistor takes effect, when reverse current passes through the device, the other resistor takes effect, and when the current directions are different, the device presents different resistance values.

The invention provides a method for extracting high-frequency characteristics of an indium-phosphorus heterojunction bipolar transistor (HBT). The method comprises the following steps: acquiring S parameter test data of InP HBTs with different sizes; extracting element parameters based on the test S parameters and the T-type small-signal equivalent circuit model of the InP HBT; obtaining a forward current gain and a unidirectional power gain under the radio frequency condition; constructing a frequency extraction model; obtaining a cut-off frequency and a maximum oscillation frequency; and constructing a geometric scalable model of the cut-off frequency and the maximum oscillation frequency based on the change rule of the cut-off frequency and the maximum oscillation frequency along with the size of the device. According to the invention, the method for extracting the cut-off frequency and the maximum oscillation frequency is defined by using the test S parameter; through testing under the multi-size and multi-bias condition, the effectiveness of the method is verified, the precision of the model is improved, and meanwhile, the time for extracting the cut-off frequency and the maximum oscillation frequency is greatly shortened.

The application provides a semiconductor structure and a forming method thereof. The semiconductor structure comprises: a substrate, the substrate comprising a first epitaxial layer and a second epitaxial layer on the first epitaxial layer; a deep well protection column, which is separated from the surface of the first epitaxial layer and extends into the first epitaxial layer and extends to below the second epitaxial layer in the width direction, and the thickness of the first epitaxial layer between the deep well protection column and the substrate is 6-12 μm; a well contact layer, which has the same doping type as the deep well protection column, extends into the deep well protection column from the surface of the deep well protection column and is surrounded by the sidewall and bottom of the deep well protection column; and a metal layer, which is located on the surface of the well contact layer and the sidewall and surface of the second epitaxial layer. The semiconductor structure and the forming method thereof can reduce the surface electric field of the device, increase the forward current and improve the reliability of the device.

A herein disclosed battery system 1 includes two kinds of contactors, i.e., a first contactor 40 and a second contactor 50. The first contactor 40 includes a first positive electrode terminal 42 connected to a positive electrode 11Ap of a battery unit 10, and includes a first negative electrode terminal 44 connected via a positive electrode output terminal 20 to an external load 100. In addition, the second contactor 50 includes a second positive electrode terminal 52 connected to a negative electrode 11Nn of the battery unit 10, and includes a second negative electrode terminal 54 connected via a negative electrode output terminal 30 to the external load 100. Then, the herein disclosed battery system 1 is configured to preferentially turn OFF the contactor, in which a forward electric current flows, during both of an electrical charge and an electrical discharge. Accordingly, the electric current can be safely and promptly interrupted, and thus it is possible to inhibit an malfunction due to welding of the contactor.