102results about "Emergency protection detection" patented technology

A motor control device includes a signal identifying unit and an overvoltage detecting unit. The signal identifying unit includes an optical isolator that converts an electrical signal supplied via a terminal to which an external device is connected and a switch that turns off a connection circuit connected to the terminal. The overvoltage detecting unit is configured to turn off the switch when a voltage applied to the connection circuit is greater than a threshold voltage.

An apparatus (100) includes a first comparator (120) having first and second inputs, a first control input, an output, and a supply voltage terminal. A second comparator (130) has first and second inputs, a second control input, and an output. The second comparator's first input is coupled to the first input of the first comparator (120). The second comparator's second input is coupled to the first comparator's second input. A switchover logic circuit (140) has an input, a first output, a second output, and a third output. The input of the switchover logic circuit (140) is coupled to the first inputs of the first and second comparators (120, 130). The first output of the switchover logic circuit (140) is coupled to the supply voltage terminal of the first comparator (120). The second output of the switchover logic circuit (140) is coupled to the first control input. The third output of the switchover logic circuit (140) is coupled to the second control input.

A generator circuit breaker includes a main current branch, a current-limiting transfer branch, a freewheeling branch and a fast switch. The main current branch includes a high-speed mechanical switch S1 and a high-speed mechanical switch S2 in parallel, wherein two ends of each of breaks of the high-speed mechanical switch S1 and the high-speed mechanical switch S2 are directly connected with wire outlet ends of the circuit breaker respectively. One end of the current-limiting transfer branch is connected in parallel to one end of the main current branch and the other end of the current-limiting transfer branch is connected with the other end of the main current branch via a fast switch S3, wherein the current-limiting transfer branch includes a transfer capacitor C, an inductor L, thyristor components T1 and T2, and a current-limiting resistor R.

A temperature sensing tape is provided and can include an insulating support structure and at least one temperature sensing element disposed on the insulating support structure wherein the at least one temperature sensing element can be formed from a single polymer mixture that includes two or more polymers, and wherein each of the two or more polymers can have a respective, different crystallinity point.

Provided are a method and apparatus for predicting a current of a load (550) in an autotransformer (540). A processor is configured to obtain a value of a current of a first input terminal (520) and a value of a current of a first stage of an autotransformer (530), predict whether a plurality of loads are unbalanced, based on the value of the current of the first input terminal (520), the value of the current of the first stage (530), and a characteristic of the autotransformer (540), and determine whether to open a relay (510), based on a result of the prediction and a current flowing through the autotransformer (540), wherein a turn ratio of the autotransformer (540) is 1.

A flexible low-frequency transmission line inverse time protection method and system are provided. The method uses single-ended electrical quantity to constitute the criterion, after the fault occurs, the signal acquisition device is used to sample the phase current and voltage, and the resulting voltage and current are subjected to the Karenbauer transform to obtain the line mode and the zero mode components, and the integral value of the fault modulus components is used to construct the transient current energy, and the transient energy is used to construct the new inverse time limit characteristic curve equation, and the transition resistance compensation coefficient is introduced to improve the inverse time limit protection performance of the inverse time protection. The method is aimed at accelerating the action time of the protection when a fault occurs in a flexible low-frequency transmission line, and adopts the fault component to construct the transient energy value.

A vehicle comprises: a low-voltage battery to provide low-voltage power; devices configured to operate using the low-voltage power, each of the devices coupled to the low-voltage battery by a corresponding conductor, wherein the devices comprise all consumers of the low-voltage power in the vehicle; switches to selectively interrupt the low-voltage power between the low-voltage battery and any of the devices, each of the switches positioned in a respective conductor of the conductors; and a central processing unit configured to detect an overload condition regarding any of the switches, and to open, in response to detecting the overload condition, the switch of the conductor between the low-voltage battery and the corresponding one of the devices.

A circuit is described herein which may be used as an electronic fuse. According to one example, the circuit includes an integrated circuit (IC) with a chip contact for connecting, during operation, a filter circuit. The IC further includes a driver configured to drive a power transistor in accordance with a logic signal; a squaring circuit configured to receive a current sense signal that represents a load current passing through the power transistor and to output, at the chip contact, a first current that represents the squared load current; a comparator circuit configured to compare a voltage present at the chip contact with a reference voltage; and a control logic configured to generate the logic signal and to cause a switch-off of the power transistor dependent on an output signal of the comparator circuit.

The application discloses a kind of comprehensive relay protection and management system based on intelligent algorithm, to realize the real-time monitoring of power system, fault detection and prediction, and relay protection control by highly integrated technical scheme.The system includes data exchange unit, programmable logic controller (PLC), intelligent data processing unit and touch screen device.Data exchange unit is responsible for the data bidirectional exchange with the sensors and devices of power system, ensures the real-time collection of system data and the effective transmission of relay protection control signal.PLC receives and processes these data, generates relay protection control signal according to the instructions of intelligent data processing unit.Intelligent data processing unit pre-processes, analyzes and predicts the collected data, provides PLC with logic control instructions based on deep learning, to optimize relay protection action.Finally, the touch screen device displays the real-time running state and fault analysis result of power system, and provides user interaction interface.

The short circuit detection circuit (100) includes a first transistor (102), a switched load circuit (110), a second transistor (104), a switched capacitor circuit (120), and a comparator (130). The first transistor is configured to conduct a load current. The switched load circuit is coupled to the first transistor and configured to switchably draw a test current. The second transistor is coupled to the first transistor. The second transistor is configured to conduct a sense current. The sense current includes first and second portions representing the load current and the test current, respectively. The switched capacitor circuit is coupled to the second transistor and configured to generate a short circuit detection voltage representing the second portion. The comparator has a first comparator input coupled to the switched capacitor circuit. The comparator is configured to compare the short circuit detection voltage with a short circuit threshold voltage.

A power generation device (1) includes: a power generator (10), a power conversion circuit (21), a first interruption circuit (23), a second interruption circuit (24), a first monitoring circuit (25) which monitors an output current flowing from the power generator (10) to the power conversion circuit (21) and outputs a first interruption signal when an absolute value of the output current exceeds a first predetermined value, and a second monitoring circuit (26) which monitors a total value of output voltages of respective phases of the power generator (10) and outputs a second interruption signal when an absolute value of the total value exceeds a second predetermined value. A first interruption circuit (23) electrically interrupts a connection between the power generator (10) and the power conversion circuit (21) in accordance with the output of the first or second interruption signal, and the second interruption circuit (24) electrically interrupts the connection between the three-phase coils (Lu, Lv, Lw) and the neutral point (N) in accordance with the output of the first or second interruption signal.

A kind of distributed feeder automation fault processing method and system, including: distribution line station terminal obtains the current of the position of circuit breaker connected therewith, the voltage at bus side and circuit breaker state, and the state of circuit breaker connected by other distribution line station terminal;Distribution line station terminal is based on the current of the position of circuit breaker connected therewith, voltage at bus side and circuit breaker state, in combination with the state of circuit breaker connected by adjacent distribution line station terminal, determines fault point;Distribution line station terminal handles the fault point.The present application detects the characteristic difference of fault section by distribution line station terminal itself, communicates between terminal, and automatically realizes the function of fault location, isolation and non-fault area power supply recovery of feeder.

The application relates to a non-full-phase power supply line comprehensive protection method, system, device and medium, characterized in that: when it is determined that traction power supply line protection at a transformer substation side has started, current and voltage information of two phases at the transformer substation side is collected; a fault element starting moment is recorded, a plurality of maximum sampling values in the former half cycle and a plurality of maximum sampling values corresponding to the latter half cycle before the moment are extracted; whether the traction power supply line at the transformer substation side appears a ground fault or a phase-to-phase fault is judged according to the current and voltage information, the extracted maximum sampling values and a first criterion, a second criterion and a voltage auxiliary criterion which are constructed in advance, and whether protection export is determined, and the application can be widely applied in the field of power supply lines.

A method and apparatus for controlling an arc suppression device of a three-phase electric network, the arc suppression device having an adjustable admittance connected between a neutral point of the three-phase electric network and earth, the apparatus being configured to determine a resonant frequency of a zero-sequence system of the three-phase electric network and determine, based on the determined resonant frequency of the zero-sequence system of the three-phase electric network, whether to initiate a tuning of the arc suppression device of the three-phase electric network.

The application discloses a ferromagnetic saturation and inrush current discrimination method and device reflecting concave-convex offset of current waveform, and the method comprises the following steps: obtaining three-phase differential current waveform according to three-phase currents of each side of a transformer, and collecting variation sequence of three-phase differential currents of the transformer based on the three-phase differential current waveform; calculating current variation difference, absolute value of the current variation difference, current period integral of the current variation difference, current period integral of the absolute value of the current variation difference, T / 3 period integral, 2T / 3 period integral and maximum number of two points of the absolute value of the current variation difference; when the sum of the T / 3 period integral, the 2T / 3 period integral, the maximum number of two points of the absolute value of the current variation difference, the absolute value of the current period integral of the current variation difference satisfies the ferromagnetic saturation and inrush current criterion reflecting the concave-convex offset of the current waveform, the inrush current or CT saturation is determined, and the differential protection is blocked. The same criterion is used, and effective identification of the inrush current and the saturation is realized.

The invention relates to a circuit breaker for an electrical circuit. The circuit breaker (100) is arranged between a power supply (302) and a load (304), wherein the circuit breaker (100) comprises control means (104) configured to switch switching means (106) of the circuit breaker (100) between an ON-mode in which a current i is fed to the load (304), and an OFF- mode in which no current is fed to the load (304); wherein the control means (104) is configured to obtain a value of the current i fed to the load (304) when the switching means (106) is in the ON-mode; keep the switching means (106) in the ON-mode if the value of the current i is smaller than a switching current is of the circuit breaker (100); switch the switching means (106) into the OFF-mode if the value of the current i is larger than the switching current is of the circuit breaker (100); and switch the switching means (106) from the OFF-mode back into the ON-mode after a first time interval Furthermore, the invention also relates to a circuit and a method.

The invention relates to a circuit breaker for an electrical circuit. The circuit breaker (100) is arranged between a power supply (302) and a load (304), wherein the circuit breaker (100) comprises control means (104) configured to switch switching means (106) of the circuit breaker (100) between an ON-mode in which a current i is fed to the load (304), and an OFF-mode in which no current is fed to the load (304); wherein the control means (104) is configured to obtain a value of the current i fed to the load (304) when the switching means (106) is in the ON-mode; keep the switching means (106) in the ON-mode if the value of the current i is smaller than a switching current iS of the circuit breaker (100); switch the switching means (106) into the OFF-mode if the value of the current i is larger than the switching current iS of the circuit breaker (100); and switch the switching means (106) from the OFF-mode back into the ON-mode after a first time interval T1. Furthermore, the invention also relates to a circuit and a method.

The present application discloses a failure detection circuit and a failure detection device, which includes a switching circuit, a bias control circuit, and a fault detection circuit. The switching circuit has a first terminal, a second terminal, and a control terminal, and connects or disconnects the first and second terminals according to a control terminal voltage. The bias control circuit is coupled to the switching circuit and changes the control terminal voltage according to a fault signal. The fault detection circuit is coupled to the bias control circuit, detects an AC component in the control terminal voltage, and generates a fault signal according to the AC component. The fault detection circuit receives a detection signal, compares the detection signal, and generates a detection result signal. When the detection result signal is a fixed level signal or non-ripple signal, the fault detection circuit generates a fault signal.

A switch for connection in an AC power distribution circuit. The switch comprising: a pair of contacts disposed within an interrupting chamber; an actuator (64) operatively coupled to the contacts and configured to open and close the contacts; a current transformer (66) arranged to harvest energy from line current; and control circuitry (68) including at least one processor and a memory. The control circuitry being configured to: detect current flowing through the switch; in response to detection of a fault current condition, open the contacts a first time using energy harvested from the current transformer (66); store, in the memory, a polarity of a last half-cycle of the detected current associated with completion of the first opening; determine a close time to close the contacts such that (i) a first half-cycle of current following re-establishment of conduction has a same polarity as the stored polarity and (ii) actuation of the closing operation ends at a zero crossing of the current; and close the contacts at the close time.

To enable easy evaluation of a protection function for semiconductor switching elements.SOLUTION: An electronic circuit according to the present embodiment includes a comparison circuit that detects a first voltage of a first node associated with a first end of a semiconductor switching element and outputs a first signal when the first voltage is a predetermined voltage or more, a first filter that includes a first switch connected between the first node and a second end of the semiconductor switching element and turns on the first switch for a first time on the basis of a control signal indicating conduction of the semiconductor switching element and a second filter that generates a second signal indicating an occurrence of an overcurrent in the semiconductor switching element when the first signal is output for a second time or more, and changes at least one of a first waveform, the second time, the first time, and the predetermined voltage related to the drive of the semiconductor switching element based on the control signal, on the basis of the second signal.SELECTED DRAWING: Figure 1

A system and method for operating a vacuum interrupter in a self-resetting interrupter. The method includes detecting fault current, opening the vacuum interrupter a first time using power harvested from the current transformer when the fault current is detected, and storing a polarity of the detected fault current when the vacuum interrupter is opened. The method then determines a close time to close the vacuum interrupter so that the current has the same polarity that was stored when the vacuum interrupter was opened and that actuation of closing the vacuum interrupter ends at a current zero crossing, closes the vacuum interrupter at the close time, and opens the vacuum interrupter a second time after the vacuum interrupter is closed using power harvested from the current transformer.

HV switch unit (HVU) comprising an HV switch (HVS) comprising several semiconductor switches (S1, S2, Si, Sn) connected in series and a method of balancing the voltage distribution over the switches (S1, S2, Si, Sn) connected in series in the HV switch (HVS), wherein a snubber arrangement (10, 10',', 12, 12', 14, 14') is associated with each switch (S1, S2, Si, Sn), comprising the steps of: a. determining a first quantity related to the snubber arrangement (10, 10', 12, 12', 14, 14') of a first switch (S1), b. determining a second quantity related to the snubber arrangement (12, 12', 14, 14') of a second switch (S2, Si, … Sn), c. comparing the first and second quantities, b. based on the comparison adjusting the drive signal (6) of at least the first switch (S1) based on the first quantity.

To provide semiconductor devices that reduce manufacturing costs. [Solution] The semiconductor device includes a power device, a boost circuit, and an overcurrent detection circuit. The overcurrent detection circuit includes a sense circuit and a detection current generation circuit DCG that generates the detection current. The detection current generation circuit comprises a first current source I1_G that flows a first current I1 from a detection output node DC_OT, a first current circuit I1_CT that supplies a second current I2 greater than the first current I1 to the detection output node, a second current circuit I2_CT that supplies a third current I3 greater than the first current, a limiting circuit LM_CT connected between the second current circuit and the detection output node to limit the voltage at the detection output node, a first control circuit C1_CT that operates on the boost voltage from the boost circuit and controls the first current circuit according to the voltage output from the sense circuit, and a second control circuit C2_CT that operates on the power supply voltage and controls the second current circuit according to the voltage output from the sense circuit.

An electric leakage detection circuit for a mining direct-current intrinsically safe power supply system, the circuit comprising a switch module (10) and an alternating-current transformer (20), wherein the switch module (10) is used for converting, by means of periodic on-off switching, a direct-current leakage current generated in a power supply circuit into a periodic pulse current, and the alternating-current transformer (20) is used for generating an induced current on the basis of the periodic pulse current. The electric leakage detection circuit can use a low-cost alternating-current mutual inductance component in a direct-current power supply system, and has the beneficial effects of a good detection effect, a simple structure, a low cost, and convenient production, installation and commissioning.

The disclosed technology relates generally to switching devices and more particularly to switching devices employing micro-electromechanical system (MEMS) switches. The switching devices can serve as circuit breakers for protecting electrical systems against certain electrical events. The switching devices can be configured to monitor and control one or both the MEMS switches and the electrical systems being protected. The disclosed technology additionally relates to systems including the switching devices and methods of using the switching devices.

A power grid protection system (100) that protects a power grid (50) including a voltage line (56) through which a current supplied from a secondary-side facility of transformation device flows and a neutral line (55) that has been grounded includes: a circuit breaker (11) installed on the voltage line (56); and a commutator (12) that connects the voltage line (56) and the neutral line (55) on a side of the secondary-side facility of transformation device with respect to the circuit breaker (11), and when an anomaly due to a short-circuit fault or a ground fault occurs in the voltage line (56), a fault current flowing through the voltage line (56) is commutated to the neutral line (55) via the commutator (12).

The present disclosure relates to a protection circuit for a high-power switching power supply and a multi-channel switching power supply. By arranging a protection switch between an input capacitor and a switching circuit of the switching power supply, the protection switch is turned off when the switching power supply experiences an abnormality, thereby protecting the switching power supply. In the multi-channel switching power supply, a protection switch is arranged between an input capacitor and a switching circuit in each channel, and when an abnormality occurs in a specific channel, the protection switch corresponding to that channel is turned off to protect the circuit structure of that channel. According to the solution of the present disclosure, since the protection switch is arranged after the input capacitor, the stress requirements on the protection switch are significantly reduced, while also lowering the cost and footprint of the protection switch.

A method for a collaborative protection mask in a wide-area protection system is disclosed. The method comprises determining, in a first zone, whether a first pair of protection relays (R5, R6) detects a fault occurrence on a first line (L3) from a first activation mask (DI) based on a first weighting factor. The method comprises determining, in the first zone, whether the first pair of protection relays detects the fault from a second activation mask (DII) based on a second weighting factor, and determining, in a second zone, whether a second pair of protection relays (R3, R8) detects the fault from the second activation mask based on the second weighting factor. The method comprises determining detections from a third activation mask (DIII) using the first, second, and third pairs of relays (R1, R10), and performing one or more operations on the first pair of relays based on the collaborative determinations.

Systems and methods are provided for a battery management system (BMS) having a protection circuit. In one example, a vehicle battery system can include a BMS including a cutoff circuit electrically coupled to the protection circuit, and a battery pack having a positive power supply line electrically coupled to the cutoff circuit, where the protection circuit can include each of an input electrically coupled to a control input of the cutoff circuit, an output electrically coupled to an output of the cutoff circuit, and a control input of the protection circuit electrically coupled to the output of the cutoff circuit. In some examples, the protection circuit can further include a low leakage current transistor configured to maintain the cutoff circuit in an open state upon detection of a reverse bias voltage. In this way, the protection circuit can mitigate accidental turn-on of the cutoff circuit.

A circuit interrupter includes a solid-state switch and a mode control circuit. The solid- state switch is serially connected between a line input terminal and a load output terminal of the circuit interrupter. The mode control circuit is configured to implement a first control mode and a second control mode to control operation of the circuit interrupter. The first control mode is configured to generate a self-bias turn-on threshold voltage for the solid-state switch during power- up of the circuit interrupter, while maintaining the solid-state switch in a switched-off state until the self-bias turn-on threshold voltage is generated. The second control mode is configured to disrupt the self-bias turn-on threshold voltage and place the solid-state switch into a switched-off state.