309 results about "Residual voltage" patented technology

The invention relates to a safe starting control method, device, equipment and medium for a bootstrap drive inverter, and the method comprises the steps: obtaining a detection voltage representing an output filter inductance voltage after responding to any starting event and before formally transmitting a drive signal; comparing the negative voltage with a preset negative voltage safety threshold value; only when the detected voltage is higher than the safety threshold, a driving enable signal is generated to allow the inverter to be normally started; otherwise, generating a driving blocking signal, carrying out detection and judgment again after waiting for preset time delay, and circulating the process until the system state enters the safe area; the method is realized by modifying a control algorithm, no power hardware needs to be added, the starting impact risk is eliminated with low cost, and the contradiction between the hardware limitation of a bootstrap drive circuit and the negative residual voltage possibly existing on the output inductance of the inverter is solved; therefore, the safety problem of direct connection between the impact current and the bridge arm during starting in an unfavorable initial state is solved.

The invention provides a dynamic residual amplification circuit based on charge sampling, and relates to the technical field of integrated circuits, the dynamic residual amplification circuit comprises an integrating circuit, a logic circuit, a charge pump and a zero-cross detection circuit, the integrating circuit is connected with the logic circuit and the zero-cross detection circuit, the integrating circuit converts a sampled input differential signal into a constant current, and the constant current is connected with the charge pump. The output node is continuously charged or discharged, so that the input differential signal is converted into a current integral quantity; the zero-cross detection circuit monitors the output voltage of the integrating circuit in real time, and when the output voltage is greater than or equal to the common mode voltage VCM, the moment when the output voltage is equal to the common mode voltage VCM is converted into a digital clock edge; the logic circuit is connected with the charge pump and outputs digital pulses to the charge pump according to the digital clock edge so as to control the reset time sequence of the whole dynamic residual amplification circuit; the charge pump is configured to output a residual voltage modulated by the digital pulse in response to the digital pulse. The application helps to improve the linearity of the residual signal.

The invention relates to the technical field of integrated circuit design, in particular to a noise shaping assembly line successive approximation type analog-to-digital converter and a control method. Comprising a first stage including an auxiliary successive approximation analog-to-digital converter and a first stage voltage processing module; the second stage comprises a dual-channel noise shaping successive approximation type analog-to-digital converter and a loop filter; the input end of the residual amplifier is connected with the first-stage voltage processing module, and the output end of the residual amplifier is connected with the noise shaping successive approximation type analog-to-digital converter; the first input end of the digital code aligner is connected with the output end of the comparator of the auxiliary analog-to-digital converter, and the second input end of the digital code aligner is connected with the output end of the second-stage comparator. According to the invention, the analog-to-digital conversion speed can be accelerated, the influence of a zero point on a residual voltage amplification coefficient is reduced, the conversion time is shortened, and the input and output common-mode voltages of the time domain converter are stabilized.

The invention belongs to the technical field of safety and stability of a power system, and relates to a coordinated operation method and system of a distributed phase modifier and a network-forming SVG (Static Var Generator). According to the invention, by obtaining the current-limiting critical voltage coefficient and the equivalent critical voltage coefficient, the cooperative operation effect of the distributed phase modifier and the network-forming SVG and the supporting capability of the system voltage support are improved; when the residual voltage coefficient is smaller than the equivalent critical voltage coefficient, the reactive power supporting capacity provided by the phase modifier is high, the phase modifier is smoothly put into operation, and the impact on the system caused by the put-in of the phase modifier is reduced; when the residual voltage coefficient is greater than the equivalent critical voltage coefficient, the phase modifier starts to smoothly exit from operation, and the impact on the system caused by the deduction of the phase modifier is reduced; and when the residual voltage coefficient is greater than the current-limiting critical voltage coefficient, the networking SVG quits the current-limiting link, the phase modifier completely quits operation, and the margin of transient reactive power regulation of the system is improved. According to the invention, safe and effective cooperative work of the network-forming SVG and the distributed phase modifier is realized.

The invention discloses an anti-backflash LED drive circuit which comprises a power supply module, a drive control circuit, a starting circuit and an auxiliary power supply circuit. The power supply module converts an input voltage into a bus voltage; the driving control circuit adjusts the duty ratio of a field effect switch tube through a first control chip, and LED constant-voltage and constant-current output is achieved. The starting circuit adopts a negative-voltage turn-off device, and is switched on to supply power to the control chip during initial power-on; the auxiliary power supply circuit inductively generates alternating voltage through an auxiliary winding coupled by a power inductor, continuously supplies power to the control chip after rectification and filtering, triggers the negative voltage turn-off device to be turned off, and cuts off a power supply path of the starting circuit; after power failure, the negative-voltage turn-off device is maintained in a turn-off state, backward flowing of residual voltage of a bus is blocked, the inductor stops oscillation to stop auxiliary power supply, power supply of the control chip returns to zero along with discharging of the capacitor, and LED back flash is eliminated through double mechanisms. According to the invention, the technical problem of LED power-off flashing back in the prior art is solved.

The embodiment of the invention relates to a power supply wake-up circuit and a vehicle-mounted power supply management system, and the power supply wake-up circuit is provided with a power supply module, a reference module, a detection trigger module and an operational amplifier processing module, a wake-up signal is generated according to the ratio of a detection voltage to a reference voltage, and the power supply module is controlled to wake up according to the wake-up signal. Meanwhile, the reference voltage larger than the wake-up threshold of the power supply chip is configured to perform specific value judgment on the detection voltage to generate the wake-up signal, so that the residual voltage interference is effectively eliminated, the wake-up reliability is improved, and the problem of power shortage of the battery caused by false triggering is avoided.

The invention relates to the field of circuit breakers, and provides a circuit breaker which comprises an insulating shell and a pull rod mechanism, a power connection end is arranged on the side face of the insulating shell, the circuit breaker further comprises a first capacitor and a second capacitor, and the first capacitor is arranged in the insulating shell and electrically connected with a first conductive metal body of the power connection end; the second capacitor is arranged in the insulating shell, a second conductive metal body electrically connected with the second capacitor is arranged at the end part of a moving contact of the vacuum arc-extinguishing chamber of the insulating shell, and a first interface and a second interface are arranged on the side wall or the end part of the insulating shell. The circuit breaker is connected for use, and the power connection end is connected with external detection or feedback equipment, so that the working state of the circuit breaker is monitored and fed back in real time. When the circuit breaker is disconnected, the first capacitor and the second capacitor can be used for detection so as to determine whether the interior of the circuit breaker is completely powered off, that is, no residual voltage exists on the power connection end and the moving contact part, so that safe and reliable operation is ensured.

The invention relates to the technical field of multi-column lightning arresters, in particular to a multi-column lightning arrester parallel matching method, which comprises the following steps of S1, performing aging screening and energy tolerance testing on zinc oxide resistor discs of the same batch; s2, measuring the direct-current reference voltage Uref of the resistor discs, the leakage current I0 under 0.75 Uref, the impact residual voltage UL under the lightning wave and the operation residual voltage US under the operation wave one by one; s3, screening the resistor discs for three times; and S4, high-low matching is carried out by taking the operation residual voltage US as a main matching basis, so that the operation residual voltage deviation of each column of series resistor disc group is smaller than a first preset value, and the direct current reference voltage numerical value deviation is smaller than a second preset value. The strict screening process ensures the consistency of the performance of the resistor discs, and the reasonable grouping mode makes the electrical performance of each column resistor disc group more balanced, thereby achieving the effect of improving the operating wave endurance capability and the current sharing characteristic of the multi-column lightning arrester, and reducing the probability of faults caused by uneven current distribution of the MOV.

The invention relates to the technical field of power fault detection, and mainly relates to a residual voltage detection circuit and a line protection device.The residual voltage detection circuit comprises a sampling circuit and a signal holding circuit, the signal holding circuit adopts double coils and comprises a first coil and a second coil, and a loop where the first coil is located is provided with a first controllable switch tube in series; the first controllable switch tube is connected when the sampling circuit collects residual voltage, a second controllable switch tube is arranged in a loop where the second coil is located in series, the control end of the second controllable switch tube is used for being connected with a feeder terminal, and the signal holding circuit further comprises a residual voltage output branch used for being connected with the feeder terminal. The residual voltage output branch is provided with a first contact of the double coils in series. A sampling circuit is used for obtaining a residual voltage signal generated at the moment of closing of a faulty power grid line, and a signal holding circuit formed by double coils is used for transmitting a sampling signal to a feeder terminal, so that the feeder terminal can still receive the residual voltage signal when the feeder terminal loses power after power supply is recovered.

The invention discloses a multi-electric-level straight drive circuit of a depletion type switching device, which is characterized in that by dynamically switching positive voltage, zero voltage and deep and shallow negative voltage, the positive voltage is utilized to reduce on resistance in a conduction stage, the deep negative voltage is utilized to quickly cut off current in a turn-off stage, and then the shallow negative voltage is switched to maintain a turn-off state, so that the static power consumption is remarkably reduced. A surge suppression circuit and a power driver work cooperatively, surge current is suppressed through a current-limiting resistor and a fast bypass switch at the moment of starting, and a short circuit Ra is formed after negative voltage is established to reduce loss; and before power failure, the capacitor stored energy is released through the active discharge switch, so that mistaken switching-on caused by residual voltage is eliminated. Through system-level innovation, the direct connection problem of a depletion type device is effectively solved, and a high-efficiency, reliable and compact solution is provided for a high-power-density power supply system.

The invention discloses a multi-physics field coupling high-resistance fault self-healing protection method, equipment and a medium. The method comprises the following steps: collecting multi-physics field coupling data and carrying out standardization processing; a multi-field coupling robust threshold value is generated based on the standardized multi-field coupling data, and the fault condition is further identified and judged; analyzing a fault condition based on a digital twinborn technology, inverting fault point data and performing multi-field cooperative adaptive arc extinction control; and self-healing recovery of robust optimization driving is carried out. According to the method, the dynamic protection threshold value is generated through a method of fusing time sequence prediction and robust optimization, wide-range fluctuation of new energy output and load can be automatically adapted, the problem that the misjudgment rate of a fixed threshold value is high when the system operation state changes is solved, and the dynamic adaptability of protection is improved; a model prediction control dynamic optimization active compensation strategy is adopted, the residual voltage and the residual current of a fault point can be actively restrained within a preset safety threshold value, and secondary accidents such as electric shock and mountain fire caused by incomplete arc extinction are avoided.

The invention discloses a direct-current power transmission system EM lightning arrester zinc oxide resistor disc selecting and balancing method, and belongs to the technical field of lightning arrester disc selecting and matching. The disc selecting method comprises the steps that S1, direct-current parameter testing is carried out, and damped and aged resistor discs are removed based on the direct-current parameter testing result; s2, applying lightning and operation impact to the resistor discs, measuring residual voltage, calculating a voltage ratio based on the residual voltage, and rejecting the resistor discs of which the voltage ratio deviation is not within a set voltage ratio threshold range; s3, carrying out square wave energy testing on the resistor discs, and removing the damaged resistor discs in the testing process; s4, performing long-wave residual voltage test on the resistor discs one by one by using the test square wave, recording a long-wave residual voltage value obtained by the test, and removing the resistor discs which are subjected to breakdown, flashover and aluminum surface burning in the test; calculating long-wave residual voltage deviation of the resistor discs under square wave excitation, and removing the resistor discs with the long-wave residual voltage deviation exceeding a set long-wave residual voltage deviation threshold value; and the sheet selection scheme of the EM lightning arrester is perfected, and the accident rate is reduced.

The invention discloses a cable branch box power supply system and a method thereof, the cable branch box power supply system comprises a three-section surge protection device, an integrated trigger type discharge gap unit, an MOV clamping unit and a residual voltage shaping network, and is cooperated with a follow-up cut-off mechanism to inhibit surge and optimize residual voltage in stages, cut off current at a voltage zero point when the surge is attenuated and a power frequency current exists, and improve the reliability of the power supply system. Electric arc and operation overvoltage are reduced; the on-line health diagnosis module analyzes the deterioration trend of a key element through equivalent parameter injection measurement and an NTC temperature probe, and uploads data through an RS-485 / Modbus bus; the dynamic load distribution module adjusts branch current in real time; the intelligent cooperative control module integrates multiple modules to realize self-adaptive linkage; the fault isolation unit is linked with the follow-up cutoff mechanism, and triggers cutoff and sends an opening signal to an upper level when the fault isolation unit is abnormal; and the event recording module is used for storing related data and supporting USB on-site calling. According to the invention, the surge resistance, the cutoff reliability and the operation stability of the system are enhanced, and the preventive maintenance capability is improved.

Methods and systems for improving fusion bonding are disclosed. Plasma treatment is performed on a substrate prior to the fusion bonding, which leaves residual charge on the substrate to be fusion bonded. The residual charge is usually dissipated through an electrically conductive silicone cushion on a loading pin. In the methods, the amount of residual voltage on a test silicon wafer is measured. If the residual voltage is too high, this indicates the usable lifetime of the silicone cushion has passed, and the electrically conductive silicone cushion is replaced. This ensures the continued dissipation of residual charge during use in production, improving the quality of fusion bonds between substrates.

The invention discloses a composite oscillation type direct-current circuit breaker, and belongs to the technical field of direct-current power transmission. Comprising a main through-current branch, an active oscillation switch circuit, a passive oscillation switch circuit, an inductance-capacitance series oscillation branch and an energy consumption branch. The passive oscillation switch circuit is connected in parallel with the high arc voltage combination switch in the main through-current branch; an active oscillation branch circuit formed after the active oscillation switch circuit is sequentially connected in series with an oscillation capacitor and an oscillation inductor is connected in parallel with the main through-flow branch circuit; and the energy consumption branch is connected with the main through-flow branch in parallel. Therefore, compared with a single oscillation mode, the current zero crossing point is generated by utilizing a multi-oscillation mode, so that the capacitance value of the oscillation capacitor is greatly reduced; a controllable energy consumption mode is utilized, and a main lightning arrester with lower reference voltage and residual voltage can be adopted in the design, so that the maximum turn-off overvoltage at the two ends of the circuit breaker is reduced, and the withstand voltage value of an oscillation capacitor, the series number of vacuum switches and the stress level of the vacuum switches are reduced. The cost is reduced, the economy is improved, and the stability of the turn-off capability is ensured.

The invention provides a power converter, and belongs to the technical field of power electronics. In the scheme provided by the invention, the lightning protection unit in the power converter comprises a piezoresistor and a gas discharge tube which are connected in series. Therefore, the action voltage of the lightning protection unit can be effectively increased on the premise that the action voltage of the piezoresistor is not increased, and it is ensured that the lightning protection unit can be suitable for the high-voltage power converter. Moreover, by connecting the divider resistor in parallel with the gas discharge tube, flexible voltage division of the piezoresistor and the gas discharge tube can be realized, so that the model selection flexibility of the piezoresistor and the gas discharge tube is effectively improved. Besides, in a lightning stroke scene, the voltage at the two ends of the gas discharge tube after action is relatively low, and the residual voltage of the lightning protection unit can be prevented from being increased, so that the requirement on the protection performance of each power device in the power converter can be prevented from being increased.

The invention relates to the technical field of ion fan testing, in particular to an analysis processing method and system for ion fan testing data. The method comprises the following steps: acquiring voltage data in a test period, extracting a rapid drop characteristic and a slow attenuation characteristic in electrostatic response data, and respectively generating a first electrostatic discharge characteristic and a second electrostatic discharge characteristic; identifying a corresponding discharge response section according to the difference; a response curve form in the section is extracted, and first neutralization time, first residual voltage, second neutralization time, second residual voltage and other electricity removal performance parameters are obtained; if the neutralization time difference and the residual voltage are both within the set threshold range, it is judged that the fan is in a stable electricity removal state, and blowing output is maintained; otherwise, it is judged that the electricity removal performance is abnormal, testing is stopped immediately, output is locked, and an alarm and data reporting mechanism is triggered; according to the invention, through ion fan testing, ion fan testing is more accurate.

The application provides a voltage converter. The voltage converter comprises a primary circuit, a secondary circuit and a discharge control unit. The secondary circuit comprises a first MOS tube and an output capacitor. The first MOS tube is connected with the discharge control unit. The discharge control unit is used for controlling the first MOS tube to work in a linear region when the voltage converter is in a shutdown state or an abnormal protection state. In the technical scheme, after the voltage converter stops working, the first MOS tube is controlled to work in the linear region, so that the first MOS tube consumes the residual voltage on the output capacitor in the voltage converter as a resistance. In this way, when the voltage converter is started, the pre-bias voltage is reduced or disappears, so that an excessively large reverse current is avoided, and thus the failure of components in the voltage converter is avoided.

The invention discloses a power unit replacement method and device and electronic equipment, and the method comprises the steps: detecting a plurality of power units in a target frequency converter system, determining a faulted power unit as a to-be-replaced power unit, and controlling the disconnection between a main busbar and the to-be-replaced power unit; when the frequency converter online replacement device is connected to an external power supply and the first terminal and the second terminal are connected to the two sides of the power unit to be replaced, the discharge unit is controlled to be started, and when the residual voltage is reduced to zero, the discharge unit is controlled to be stopped; under the condition that the to-be-replaced power unit is replaced by the target power unit, the boost unit is controlled to be started, and under the condition that the actual voltage rises to the preset voltage, the boost unit is controlled to be stopped; and the control main busbar is connected with the target power unit. Therefore, the residual voltage is safely discharged through the discharging unit, the boosting unit is used for pre-charging, online replacement can be completed without powering off a direct-current busbar, and continuous production is guaranteed.

The embodiment of the application discloses a high-voltage controllable arrester current and energy real-time monitoring protection system and method, the system comprises a high-voltage controllable arrester, the high-voltage controllable arrester comprises an arrester fixing element, an arrester controllable element and a control switch; a current measurement module for measuring current; an energy calculation module for obtaining the arrester action residual voltage and the fixed part arrester absorption energy when performing closing operation; a protection module for performing current imbalance protection and arrester energy over-limit protection. The method comprises the following steps: measuring the current of the high-voltage controllable arrester; obtaining the arrester action residual voltage and the fixed part arrester absorption energy when performing closing operation; and performing current imbalance protection and arrester energy over-limit protection. The application enables the device to exit in time under extreme operating conditions, thereby protecting the safe and stable operation of the device.

The utility model relates to the technical field of switching power supplies, in particular to a starting circuit of a switching power supply, which comprises a starting input port, a power supply input port, a PWM (Pulse Width Modulation) control chip U1, a starting module, a power supply module and a linear voltage stabilizing module, the starting module comprises a capacitor C3, a resistor R12, a diode D2 and a switching tube Q2; the power supply module comprises a capacitor C2, a resistor R4 and a resistor R8; the linear voltage stabilization module comprises a switch tube Q3 and a resistor R5. According to the utility model, through the arrangement of the starting module, the power supply module and the linear voltage stabilization module, no residual voltage is transmitted to the power supply end of the PWM control chip U1 when the switching power supply is switched off, so that the power supply end of the PWM control chip U1 can be quickly initialized, and when the starting power supply is input at the starting input port again, the PWM control chip U1 can also be quickly and normally started.

The invention provides a method for improving PT residual voltage frequency measurement accuracy based on rotation vector characteristics, and relates to the technical field of generator set rotation speed measurement. The method comprises the following steps: acquiring a three-phase voltage alternating current signal through a generator end PT; processing the three-phase voltage signal to obtain projections of a voltage rotation vector on alpha and beta static coordinate axes; frequency characteristics are extracted based on projection and voltage amplitude and can be realized through direct calculation or a phase locking link; performing low-pass filtering on the frequency characteristic direct current quantity; a generator speed is calculated based on the filtered frequency and provided to a governor. According to the method, the limitation that a traditional PT residual voltage method only depends on zero crossing point information is broken through, frequency characteristics are extracted through a complete voltage sequence, alternating current signal filtering distortion is avoided through direct current filtering, high measurement precision and high anti-interference capacity can still be kept under the low-speed working condition, the problems that an existing speed measurement method is insufficient in precision and weak in anti-interference capacity are effectively solved, and the method is suitable for popularization and application. And reliable guarantee is provided for safe and stable operation of a unit.

The utility model discloses a primary protection low residual voltage lightning protection module, and relates to the technical field of circuit protection. The gas discharge circuit comprises a first temperature fuse F1, a second temperature fuse F2 and a gas discharge tube GDT1, a second piezoresistor MOV2 is connected between the first temperature fuse F1 and the gas discharge tube GDT1, and a third piezoresistor MOV3 is connected between the second temperature fuse F2 and the gas discharge tube GDT1. A first voltage dependent resistor MOV1 and a semiconductor discharge tube TSS1 are sequentially connected between the first temperature fuse F1 and the second voltage dependent resistor MOV2 and between the second temperature fuse F2 and the third voltage dependent resistor MOV3. According to the utility model, the temperature fuse can be disconnected under the condition that the surface temperature rises when the piezoresistor MOV1 or the semiconductor discharge tube TSS1 fails, so that the lightning protection function is realized, the lightning protection effect is good, and electric equipment can be better protected.

A signal switching circuit and a display panel, the signal switching circuit comprises a time sequence control module, a level conversion module, a pulse generation module and a signal switching module, the level conversion module is electrically connected with the time sequence control module and used for being electrically connected with a gate drive circuit, and the pulse generation module is electrically connected with the level conversion module and used for being electrically connected with the gate drive circuit. The signal switching module is electrically connected with the time sequence control module, the level conversion module and the pulse generation module, and before the display panel is powered on and initialization of the time sequence control module is completed, the pulse generation module is used for outputting square-wave pulses to the gate drive circuit through the signal switching module and the level conversion module; the timing control module is used for outputting a display timing signal to the gate drive circuit through the signal switching module and the level conversion module to eliminate the residual voltage of the gate drive circuit, after the timing control module is initialized, the timing control module is used for outputting the display timing signal to the gate drive circuit through the signal switching module and the level conversion module, the denoising effect of the display panel is improved, and the production cost of the display panel is reduced.

The present application relates to aerospace, geological exploration and micro-light detection fields, and particularly relates to a reconfigurable noise shaping successive approximation register analog-to-digital converter, which comprises a sampling unit, a capacitive digital-to-analog converter array, a comparison unit, a passive noise shaping feedback unit, a successive approximation control unit, an output unit and a mode control unit. The sampling unit samples and holds an input signal, and the capacitive digital-to-analog converter array outputs to the comparison unit. The comparison unit compares its output with a common-mode reference voltage, and the result is sent to the successive approximation control unit. In the noise shaping mode, the successive approximation control unit additionally generates an integral clock timing to activate the passive feedback unit, samples a residual voltage and feeds back to the digital-to-analog converter array. The output unit drives the conversion result to a lower circuit. The present application also contains a method. The present application can effectively suppress the capacitive parasitic effect and low-frequency noise, realize flexible switching between high-speed conventional mode and high-resolution noise shaping mode, and significantly improve the system performance.

The invention discloses an adjustable self-bias closed-loop ring amplifier which comprises a first-stage MOS tube, a second-stage MOS tube, a third-stage MOS tube and a bias resistor unit, each stage of MOS tube comprises two MOS tubes, grid electrodes of the two MOS tubes of the first-stage MOS tube are connected and then connected with an input node, an output of the first-stage MOS tube is connected with grid electrodes of the two MOS tubes of the second-stage MOS tube, and the bias resistor unit is connected with the first-stage MOS tube and the second-stage MOS tube. The bias resistor unit is connected between drain electrodes of two MOS tubes in the second-stage MOS tube, partial voltage of the bias resistor unit is used for generating a first bias voltage and a second bias voltage, the first bias voltage and the second bias voltage are respectively connected with grid electrodes of two MOS tubes of the third-stage MOS tube, and an output end of the third-stage MOS tube is used for outputting voltage to a rear-end circuit. The adjustable self-biased closed-loop ring amplifier can quickly amplify residual voltage, is suitable for high-speed occasions, can also realize higher gain, and can work in a sub-threshold value by biasing the MOS tube, so that the stability of the adjustable self-biased closed-loop ring amplifier is improved. The invention further discloses a switched capacitor circuit comprising the adjustable self-biased closed-loop ring amplifier.

The invention discloses a discharge indicating device with an audible and visual alarm function and a use method, and belongs to the technical field of electric power inspection and maintaining.The discharge current on a discharge grounding wire is collected through a collection unit, the collected current amount is converted into voltage amount through a comparison unit, the voltage amount is compared with a set comparison value, and when the discharge current is larger than the set value, the audible and visual alarm function is given out. When the discharge current is smaller than a set value, the comparison unit outputs voltage, and when the discharge current is smaller than the set value, the comparison unit does not output voltage, and the output voltage of the comparison unit is amplified through the amplification unit to drive the acousto-optic unit to give an acousto-optic alarm to prompt that a discharged object has residual voltage. The problems that in the prior art, the discharging condition cannot be mastered, and it cannot be guaranteed that a test object is reliably discharged are solved; the discharge reliability is ensured through sufficient time, a large amount of working time is consumed, and the working efficiency is reduced; and potential safety hazards are caused to personnel and test equipment due to insufficient discharge.

The application discloses a kind of transient diodes. Including: device main body;The device main body includes: at least one first bidirectional semiconductor chip, at least one second bidirectional semiconductor chip and conductive layer;The conductive layer is arranged between the first bidirectional semiconductor chip and the second bidirectional semiconductor chip, so that the first bidirectional semiconductor chip and the second bidirectional semiconductor chip are connected in series;Wherein, the first bidirectional semiconductor chip is N-type substrate bidirectional semiconductor chip, and the second bidirectional semiconductor chip is P-type substrate bidirectional semiconductor chip.The application provides a kind of transient diodes, realize to reduce transient diode residual voltage, improve the protection ability of device.

This invention discloses a multi-condition access, dynamic hierarchical switching, and event-related metering method and system for low-voltage emergency power supply. The method first collects data on the user-side interface residual voltage, original power supply isolation status, grounding status, emergency power supply output parameters, and load operating status, and then performs a multi-condition access determination. After successful access, a test load is connected to estimate the available power supply capacity and start-up impact margin under the current operating conditions. Next, loads to be restored are grouped according to load priority and electrical impact severity, and reserve margin verification and dynamic connection are performed for each group. After mains power is restored, loads are decoupled in reverse order and regular power supply is restored, outputting the event-related metering traceability results. This invention can improve the safety access capability, capacity utilization efficiency, and post-event traceability capability of low-voltage emergency power supply.

The present invention discloses a protection circuit for a weak current power supply port and a protection method therefor. The protection circuit includes a high-voltage protection sub-circuit, a filtering and delaying sub-circuit, a residual voltage absorption sub-circuit, and a damping sub-circuit that are connected in sequence. One end of the high-voltage protection sub-circuit is connected to the weak current power supply port, and the other end is connected to the filtering and delaying sub-circuit, which is used for high-voltage protection of the weak current power supply port. The filtering and delaying sub-circuit uses its own generated delay effect to enable the high-voltage protection sub-circuit to respond prior to the residual voltage absorption sub-circuit. The residual voltage absorption sub-circuit is used for absorbing the residual voltage that is not completely discharged after the varistor in the high-voltage protection sub-circuit is broken down. The damping sub-circuit is used for increasing the inductive reactance of the inductance coil, generating a damping effect, and suppressing the common-mode interference current. By adopting the present invention, multi-stage protection and filtering can be performed through the protection circuit to eliminate common-mode interference and differential-mode interference, and achieve protection against EFT and Surge.