39 results about "Ground failure" patented technology

A ground fault determination system includes an acquisition unit that acquires the degree of deterioration of a plurality of fuel cell stacks connected in parallel with each other and connected to an inverter, a ground fault detection unit that detects insulation resistance between the inverter and the plurality of fuel cell stacks, a first determination unit that determines, when the deterioration of each fuel cell stack has not yet progressed, whether there is a ground fault with all the fuel cell stacks all at once, and a second determination unit that determines in turn, when the deterioration of at least one fuel cell stack has progressed, whether there is a ground fault with each fuel cell stack.

The invention relates to an initiating explosive device grounding state monitoring device and method, and belongs to the technical field of initiating explosive device safety monitoring, and the device comprises N * M measurement and control combinations, N sets of measurement and control combinations and a set of main control computer, the measurement and control combination and the arrangement in a dangerous area for storing the initiating explosive devices adopt explosion-proof design, and the main control computer is arranged in a management area outside the dangerous area without adopting the explosion-proof design; each set of measurement and control combination is connected with M sets of measurement and control combinations, and the N sets of measurement and control combinations are connected to the main control computer; connecting the initiating explosive device to the corresponding measurement and control combination; the measurement and control combination obtains an in-place state by performing in-place monitoring on the initiating explosive device, and performs a grounding resistance test on the in-place initiating explosive device to obtain a grounding state signal; and the main control computer manages and controls the N sets of measurement and control combinations, receives and displays the in-place and grounding states of the initiating explosive device, judges a grounding fault and gives an alarm. The initiating explosive device safety management system has remarkable advantages in the aspect of improving the efficiency and safety of initiating explosive device safety management.

To provide a ground fault detection device, a ground fault monitoring device, and a ground fault monitoring system capable of stably detecting both ground faults caused by lightning strikes and ground faults caused by contact with flying objects such as birds and animals.SOLUTION: A ground fault detection device installed on a tower leg of a power transmission tower 2 and for detecting ground faults includes: a ground-fault current detection unit 12, 14 that outputs an activation signal triggered by current flowing through the tower leg; magnetic sensors 16 and 17 that measure magnetic flux density due to ground fault current; and a control unit 15 that causes the magnetic sensors 16 and 17 to measure the magnetic flux density due to the ground fault current when the activation signal is received from the ground-fault current detection unit 12, 14.SELECTED DRAWING: Figure 1

The utility model belongs to the technical field of power distribution network grounding protection, and discloses a grounding protection device for a power distribution network, which comprises a grounding electrode, a protective shell and a soil humidity adjusting mechanism, the grounding electrode is detachably arranged in the protective shell, the protective shell is provided with a plurality of through holes, and the soil humidity adjusting mechanism is arranged in the protective shell. The soil humidity adjusting mechanism comprises a water storage tank, the lower end of the water storage tank is communicated with a water outlet pipe, a water valve is installed on the water outlet pipe, and a water outlet of the water valve is communicated with the interior of the protective shell through a connecting hose. Therefore, the reliability of the grounding effect is improved, and the problem of grounding failure caused by too low soil humidity is avoided.

The application relates to the technical field of relay protection, in particular to a fault phase selection method for a wind farm sending-out line based on transient waveform-energy multi-feature fusion and application thereof. Wavelet energy of each-phase current fault component is used as a horizontal axis, and a fractal dimension thereof is used as a vertical axis, so that a two-dimensional plane with two types of minimum enclosing circles is formed; a fault sample is projected onto the two-dimensional plane; and a distance between the fault sample and a two-class minimum enclosing circle region on the two-dimensional plane is used as a fault phase selection criterion; and the fault phase selection is performed when a ground fault is excluded according to the size of zero-mode voltage. The required time window is short, and the problem that fault phase selection is inaccurate when a far-end high resistance is identified by a traditional phase selection method is overcome. The application aims to solve the problem of how to perform fast and accurate fault phase selection for a wind farm sending-out line without relying on power frequency quantities.

To accurately pinpoint the fault location and detect ground fault accidents early. [Solution] An information processing device having a processor and a memory device acquires fault information from a plurality of measurement terminals installed at multiple points on a power distribution line, including a first current value which is the current value of the surge current when the power distribution line has a ground fault, and a second current value obtained based on the first current value and having an amplitude smaller than the amplitude of the first current value. When the amplitude of the first current value is greater than or equal to a predetermined threshold, the time when the second current value first reaches its peak value is determined for each of the multiple measurement terminals as the surge arrival time when the surge current reaches the plurality of measurement terminals, and the ground fault point where the ground fault occurred is determined based on the difference in the surge arrival times between adjacent points.

The embodiment of the invention provides a ground fault identification method, system and device of a power system and a storage medium, and belongs to the field of power system protection and control. The method comprises the steps of receiving a fault record file sent by a power distribution terminal; obtaining a zero-sequence current waveform according to the fault record file; performing local feature extraction on the zero-sequence current waveform to obtain fault feature data; inputting the fault feature data into a preset long and short term memory classification model to obtain fault probabilities of a plurality of preset grounding fault cause categories; the multiple grounding fault cause categories comprise an external force wire breaking category, an insulation damage category and a foreign matter wire lapping category; and according to the fault probability of each grounding fault reason category, determining a grounding fault target reason and outputting the grounding fault target reason. According to the embodiment of the invention, the reason causing the grounding fault can be identified.

A ground fault detection system for a power system having a DC link, a battery bank, a link capacitor unit connected to the DC link, and plural power converters connected to the DC link. The power converters convert first DC power from the DC link to at least one of AC power or second DC power for powering at least one electrical load. A control unit disconnects the battery bank from the DC link responsive to detection of a ground fault, to deactivate operation of the power converters, and to sequentially at least partially activate, with power from the link capacitor unit, each of the power converters individually until a sensed voltage signal of the DC link is indicative of the ground fault being associated with one of the power converters.

The invention discloses a green grounding method and system for a new energy station. The method comprises the steps of obtaining multi-source grounding parameters such as soil resistivity, station topology, meteorological data and a fault current predicted value; a grounding grid optimization configuration parameter is generated through a dynamic weighted fusion algorithm; constructing a self-adaptive grounding grid structure comprising an adjustable grounding electrode depth module and a variable topology connection module; monitoring the state of the grounding grid in real time and dynamically adjusting; when a ground fault is detected, a green arc extinguishing strategy is started, and the pre-embedded energy storage element and the power electronic device are utilized to actively guide and extinguish the arc. According to the invention, the problems of poor environmental adaptability and poor fault arc extinction effect of the grounding system of the new energy station are solved, and the reliability, safety and intelligent level of the grounding system are significantly improved through dynamic adaptive adjustment and an active arc extinction strategy.

The invention discloses an active prevention and control system for sand foundation damage under the earthquake action and a construction method of the active prevention and control system. The system comprises a main body structure pressed into a sand stratum, earthquake frequency obtaining units annularly distributed on the periphery of the main body structure and a power supply unit on the top. The main body structure comprises an analysis feedback unit, an execution unit and a reinforcement unit, the analysis feedback unit receives seismic frequency data and generates an anti-phase waveform instruction, and the execution unit vibrates to weaken the seismic action; and under the high-strength earthquake working condition, the earthquake load effect rises, the pore water pressure rises to the preset threshold value, the reinforcing units are triggered, the reinforcing grout flows out of the honeycomb grid-shaped side wall, and grouting reinforcement of the foundation is achieved. The construction method comprises the steps of site exploration, drilling operation, unit layout, structure lowering, connection debugging and effect detection. By means of the principle of interference reduction, through the synergistic effect of active vibration reduction and instant reinforcement, full-stage prevention and control of sand liquefaction are achieved, the response speed is high, and the reinforcement effect can be achieved to the maximum extent.

A ground fault in a vehicle drive unit comprising an inverter is detected. The input side of the inverter is connected to a floating DC supply voltage and is controlled by a control device 12. The con

The invention relates to the technical field of power system relay protection, in particular to a ground fault distance protection method based on zero-sequence direction and angle adjustment, and the method comprises the steps: obtaining a three-phase voltage and a three-phase current, and determining a zero-sequence direction; and if the zero-sequence direction is a positive direction and the phase comparison angle of the distance relay is within a first angle range, or if the zero-sequence direction is a negative direction and the phase comparison angle of the distance relay is within a second angle range, determining that the distance relay is in an action state. And if the zero-sequence direction is a positive direction, and the distance relay is in an action state, the zero-sequence reactance relay is in an action state, and the load relay is in an action state, or if the zero-sequence direction is a negative direction, and the distance relay is in an action state, and the zero-sequence reactance relay is in an action state, executing a distance protection action. According to the invention, when the line has the grounding fault through the transition resistor, the distance protection action is executed, the fault is removed, and the stability of power grid operation is improved.

The application discloses a kind of distribution line ground fault detection device, it is related to distribution line fault detection technical field, including telescopic part, extension pipe, suspension assembly, calliper receiver, telescopic part includes central section and multiple telescopic sections, bottom of outermost telescopic section is provided with bottom disc, the top of central section is provided with connecting frame, connecting frame is provided with winding drum, and the winding drum is wound with pull rope, the top of central section is provided with guide cylinder, and pull rope passes through guide cylinder and is connected with bottom disc;Telescopic section and the outside of central section are provided with L-shaped slot, and the inside of telescopic section is provided with cooperation ball, and cooperation ball and inside corresponding L-shaped slot are mutually matched;By telescopic part, suspension assembly and calliper receiver are sent to distribution line part, and meanwhile, telescopic part is controlled to be shortened again, so that detection device realizes remote control self-inspection, and the influence of field terrain environment on inspection efficiency is avoided.

The application relates to a variable-speed pumped storage unit stator ground fault and rotor ground fault arc extinguishing method and device based on machine end injection. In the case that a variable-speed pumped storage unit ground fault is monitored, the minimum actual voltage corresponding to the phase of the three phases of the variable-speed pumped storage unit is determined as a fault phase, a first electric signal is obtained in the case that the ground fault is a stator ground fault; then, according to the first electric signal, a first arc extinguishing compensation amount is determined, the first arc extinguishing compensation amount is injected from the machine end of the variable-speed pumped storage unit to the stator winding, so that effective arc extinguishing of the stator ground fault is realized; in the case that the ground fault is a rotor ground fault, an injection signal and a second electric signal are obtained, then, according to the injection signal, the fault phase and the second electric signal, a second arc extinguishing compensation amount is determined, the second arc extinguishing compensation amount is injected from the machine end of the variable-speed pumped storage unit to the rotor winding, so that effective arc extinguishing of the rotor ground fault is realized.

The invention relates to a line selection control method and device for a single-phase earth fault feeder, equipment and a medium. The method comprises the following steps: calculating and determining a fault feeder characteristic current of each feeder to be detected and a non-fault feeder characteristic current of a non-fault feeder; calculating and determining a third difference value between the zero-sequence current after the fault of the to-be-detected feeder line and the fault feeder line characteristic current of the to-be-detected feeder line so as to determine the final zero-sequence current of the to-be-detected feeder line, and calculating and determining a fourth difference value between the zero-sequence current after the fault of the non-fault feeder line and the non-fault feeder line characteristic current of the non-fault feeder line so as to determine the final zero-sequence current of the to-be-detected feeder line. And detecting whether a difference value between the phase of the final zero-sequence current of the to-be-detected feeder and the phase of the final zero-sequence current of the non-fault feeder reaches a preset phase angle difference threshold value or not, and if so, determining the to-be-detected feeder as a fault feeder. According to the invention, the inherent unbalanced interference of the feeder line is stripped, so that the high-resistance grounding fault line selection problem is effectively solved.

This utility model belongs to the field of power maintenance technology, specifically a grounding wire clamp for substation operation and maintenance, including an insulating rod; a U-shaped rod is fixedly connected to the top of the insulating rod; a sliding groove is formed in the middle of the insulating rod; a limit rod is rotatably connected to the middle of the sliding groove via a torsion spring; a connecting rod is rotatably connected to the end of the limit rod away from the sliding groove; the other end of the connecting rod is slidably connected to the middle of the sliding groove; a groove is formed at the end of the U-shaped rod away from the insulating rod; a connecting assembly is installed inside the end of the connecting rod connected to the limit rod; the connecting assembly includes a pull rope; a through groove is formed at the end of the connecting rod located in the middle of the sliding groove; with the above structure, when grounding outdoor power lines, the occurrence of grounding failure due to the power line shaking off the device caused by wind vibration can be reduced, thus improving the safety of the device.

The invention provides a method, a control unit and an energy storage system for locating a ground fault. Disclosed herein is a method (100) for locating a ground fault in an energy storage system (20) comprising a plurality of strings (21) in parallel. The string includes a plurality of energy storage cells (22) connected in series, and the energy storage cells include one or more energy storage modules (24), and a bypass circuit (26). The method comprises: for each string of the energy storage system, identifying (110) an energy storage cell candidate (122) as a potential ground fault location based on a number of energy storage cells (116) in the string, a pole imbalance voltage (112), and an energy storage system voltage (114); and determining (120) in which string a ground fault is located by successively bypassing at least some of the identified energy storage cell candidates in a string at a time and identifying a string measured to have a deviation from the predicted behavior.

The application discloses an experimental method for evaluating the ignition ability of a grounding fault, installs N grounding stakes which are vertically inserted into the ground and are in parallel, touches the fire wire and the external conductor in different contact modes to generate a fault, and places external combustibles of different materials at the contact points; test data is measured during the touching process, and the ignition of the combustibles is observed; the ignition ability value is calculated according to the test data, and an ignition ability matrix is obtained; the ignition probability of the grounding fault for various combustibles is calculated according to the ignition ability matrix; and the ignition ability of the combustibles is classified according to the ignition probability of the combustibles. The application realizes the simulation and evaluation of the ignition ability of different combustibles under different conditions, records the corresponding ignition conditions, realizes the quantitative evaluation of the fire hazard of the grounding fault, provides a reference for the prevention and treatment of the fire hazard of the grounding fault, and reduces the life and property safety loss caused by the grounding fault fire.

The application discloses a kind of power distribution network single-phase ground fault active defense method and system.The method utilizes intelligent monitoring terminal and main control unit to implement whole-process active defense: before fault occurs, by analyzing the change trend of line-to-ground insulation resistance, generating insulation deterioration early warning and locating hidden danger section;At the moment of fault occurrence, control neutral point active grounding compensation device injects compensation current equal to fault current amplitude, opposite in phase, and quickly extinguishes fault arc;After arc extinguishing, by injecting low-frequency characteristic signal with monitoring terminal, precise positioning and isolation of fault section are realized.The application changes passive defense into active intervention, effectively solves the problem of traditional arc extinction incompleteness and line selection difficulty, significantly improves the power supply reliability and safety of power distribution network.

The invention discloses a ground fault processing method based on arc suppression coil parallel connection switchable small resistor control. The method comprises the steps that an arc suppression coil is set to be in an automatic compensation working mode, and a small resistor is not input; neutral point zero-sequence voltage and zero-sequence current signals of all lines are monitored in real time; when the neutral point zero-sequence voltage exceeds a preset neutral point zero-sequence voltage normal value upper limit value, determining that a grounding fault occurs; when the occurrence time of the grounding fault continuously exceeds a first duration or intermittent multiple discrete accumulations meet a first condition, inputting a small resistor; according to the neutral point zero-sequence voltage and the zero-sequence current signal of each line, analyzing the type of a grounding fault and the position of the line; and the line protection device acts to cut off the fault line. According to the invention, a novel control strategy that the arc suppression coil is connected in parallel with the switchable small resistor during a single-phase grounding fault is provided, and automatic elimination of a transient fault and accurate identification and processing of various faults such as a continuous grounding fault and intermittent arc grounding are realized.

The utility model relates to the field of compressor grounding, in particular to a compressor grounding assembly which comprises a mounting plate, a connecting protrusion is welded to the center of the outer wall of one side of the mounting plate, a connecting screw is welded to the center of the connecting protrusion, and combination holes distributed at equal intervals are formed in the outer wall of the mounting plate. An insertion assembly is arranged on the outer wall of the other side of the mounting plate and located at the combination hole; the threaded rods are welded to the outer wall of one side of the combination plate at equal intervals, the rotating shaft is installed in the center of the outer wall of the other side of the combination plate, and the extension rod is installed on the outer wall of the other end of the rotating shaft. The nut is in threaded connection with the outer wall of the connecting screw to fix the connecting terminal in the connecting groove, the pin shaft is inserted into the pin hole in the outer wall of the connecting screw, and the pin shaft is in contact with the outer wall of one side of the nut, so that grounding failure of the wiring terminal caused by loosening of the nut is avoided, and connection and positioning are facilitated.

The occurrence of a ground fault can be detected more accurately. A ground fault detection device is for detecting a ground fault in a conductive path for supply of power from a first power source to a second load in an in-vehicle system. The ground fault detection device includes a voltage detection unit that detects a voltage value of the conductive path, a current detection unit that detects a current value of the conductive path, and a control unit that determines whether or not a ground fault occurred in the conductive path, based on an evaluation value that increases as the voltage value detected by the voltage detection unit decreases, and based on the current value detected by the current detection unit.

There is disclosed herein a method for locating a ground fault in an energy storage system comprising a plurality of parallel strings. A string comprises a plurality of energy storage units connected in series and an energy storage unit includes one or more energy storage modules and a bypass circuit. The method comprises for each string of said energy storage system, identifying an energy storage unit candidate as a potential ground fault location based on a number of energy storage units in the string, a pole unbalance voltage and an energy storage system voltage, and determining in which string the ground fault is located by successively bypassing, one string at a time, at least some of the identified energy storage unit candidates and identifying the string for which a deviation from an expected behaviour is measured.

The application discloses a kind of single-phase grounding fault positioning methods of wind farm based on zero sequence power balance, comprising: before and after wind farm grounding fault, the power of net is measured respectively in the low voltage side of main transformer;According to the principle of zero sequence power balance, single-phase grounding fault transition resistance is obtained;According to the transition resistance of grounding fault, zero sequence voltage and zero sequence current, the distance of single-phase grounding fault point and bus of collection line is obtained.The single-phase grounding fault transition resistance of single-phase grounding fault of collection line is calculated using the change of zero sequence power before and after fault, and then the distance of single-phase grounding fault point and bus of collection line is obtained, the positioning of single-phase grounding fault is realized, the problem that single-phase grounding fault of overhead line of wind farm collection line occurs frequently, fault point positioning is difficult, and power supply recovery time is long is solved, and the utilization rate of wind power is improved.

The present application belongs to the field of power system relay protection, and provides a coal mine power grid mine cable high resistance grounding fault line selection method and system, based on the zero sequence current of each line before and after the fault, the zero sequence current vector of each line before and after the fault is calculated; according to the difference of the zero sequence current vector of each line before and after the fault, the zero sequence current variation of each line before and after the fault is determined; based on the zero sequence current variation of each line before and after the fault, signal detection is carried out by using the oscillator chaotic system, and the output phase diagram of different lines is obtained; according to the state of the output phase diagram of different lines, the fault line selection is carried out, and the fault line is determined. The present application uses the principle that the phase and amplitude of the zero sequence current variation of the fault line are different from those of the non-fault line, and the zero sequence current variation of the non-fault line is the same, to determine the fault line, and under the condition of three-phase load imbalance, the fault line can still be determined, thereby improving the accuracy and universality of high resistance grounding fault line selection.

A device for preventing electric shock and fire according to the present invention includes one or more fault detectors having one end electrically connected to at least one of two or more earth-isolated power lines with a resistance value greater than or equal to a predetermined earth resistance value and a first neutral point having a potential between the voltages of the two or more power lines, and the other end electrically connected to earth, wherein the fault detector detects a leakage current by forming a current path for the leakage current flowing from the two or more power lines or the first neutral point to earth.Therefore, according to the present invention, by detecting a leakage current between a power line, which is insulated from the earth and supplies power, and the earth, limiting the detected leakage current, which is a dangerous or lesser current, or cutting off the flow of leakage current in a human body or peripheral installations, it is possible to prevent electric shock and the occurrence of fire during the leakage current.