632 results about "Voltage sensor" patented technology

The invention relates to the technical field of power grid monitoring, and discloses a voltage sensor multi-parameter real-time monitoring method and device in an Internet of Things environment. According to the method, real-time voltage fluctuation data of a target area is acquired by deploying a multi-channel voltage sensor array and is transmitted to an edge computing node; dynamic feature extraction is executed in the edge nodes, and a multi-dimensional feature matrix containing voltage fluctuation ratio, harmonic distortion and phase deviation features is generated; identifying voltage sag, overvoltage and harmonic resonance event characteristics based on an anomaly detection model; spatial correlation modeling is carried out in combination with power grid topological structure parameters, the coupling strength of adjacent sensor node parameters is calculated, and a multi-parameter correlation map containing event propagation paths and influence ranges is generated; inputting the voltage into a diagnosis model to generate a power grid state diagnosis report, and dynamically adjusting the sampling frequency and filtering parameters of the voltage sensor according to the power grid state diagnosis report. According to the method, real-time monitoring and analysis of multiple parameters of the power grid can be realized, and comprehensive support is provided for power grid state evaluation.

The invention relates to the technical field of power equipment state monitoring, and particularly discloses a power cable operation state real-time evaluation system based on multi-mode deep learning, and the system comprises the steps: synchronously collecting the load, partial discharge and temperature strain data of a cable through a current and voltage sensor, an ultrahigh frequency sensor and a distributed optical fiber sensor; feature extraction and cross-dimension fusion are carried out on the multi-source data, and a multi-dimensional feature matrix is constructed; a pre-trained deep learning model is utilized to analyze internal association between the features, and cable health degree scores, fault risk levels and defect type identification results are output; automatically generating and executing a load adjustment, loop switching or precise maintenance strategy according to an evaluation result; according to the method, the problems of inaccurate evaluation and early warning lag caused by data isolation analysis of a traditional monitoring method are solved, and real-time accurate evaluation and intelligent closed-loop operation and maintenance of the operation state of the cable are realized.

A control system for an AC-DC converter includes a mixed-signal power controller and first and second gate drivers. The controller has a digital module and an analog module. The analog module has a current sensor generating a current sense voltage based on a sensed switch current. The digital module has a DC voltage sensor generating a DC sense voltage based on a DC bus voltage, and an AC voltage sensor generating an AC sense voltage and a binary polarity signal based on the AC voltage. The digital module induces the first gate driver to output first and second control signals for controlling a high-side switch and a low-side switch of a current shaping half-bridge based on first and second clock signals and the comparator voltage, such that an inductor current flowing through an inductor is proportional to a current command value.

The invention discloses a remote real-time monitoring and fault early warning method for a power supply operation state, and relates to the technical field of power electronics and energy management, and the method comprises the steps: collecting the temperature data of a key part of a power supply through an optical fiber Bragg grating sensor array, and analyzing the wavelength offset; electrical parameters are collected through a differential MEMS current / voltage sensor, and a permalloy / ferrite composite shielding layer is arranged in the sensor; collecting a mechanical vibration signal through a piezoelectric ceramic vibration sensor; for device data from different manufacturers, Modbus and CAN heterogeneous protocols are matched and analyzed through a regular expression, and the Modbus and CAN heterogeneous protocols are converted into a unified RDF triple format; inputting temperature, current and vibration data into a space-time alignment module, and constructing a semantic mapping relation by adopting an ontology; calculating a sensor confidence coefficient weight, and performing weighted fusion to generate an equipment health index; operating a lightweight LSTM model at an edge node, and detecting current harmonic and vibration resonance frequency band abnormity in real time; cOMSOL multi-physical field simulation is combined at the cloud end, and the evaporation rate of the capacitor electrolyte is predicted.

The invention discloses an electric meter data storage method of a single-phase cost-control electric energy meter, and relates to the technical field of intelligent electric meter data processing, and the storage method comprises the following specific steps: S100, data acquisition and characteristic pro-analysis: acquiring voltage, current and power data of the single-phase cost-control electric energy meter through a voltage sensor and a current sensor, by integrating the voltage sensor and the current sensor, real-time and accurate acquisition of key power utilization data of voltage, current and power of the single-phase charge-control electric energy meter is realized, and by introducing a dynamic time window setting mechanism, the length of a time window is automatically adjusted according to the fluctuation amplitude of the data, so that the accuracy of power utilization is improved. It is ensured that a window is shortened to capture transient changes when data fluctuates violently, the window is prolonged to reduce redundant collection when the data is stable, the flexibility and accuracy of data collection are improved through intelligent adjustment, subsequent data processing can be conducted based on richer and more detailed feature information, and the data collection efficiency is improved. And the intelligent level of the whole data storage system is obviously improved.

A system includes a circuit protection device (CPD) having an input coupled to an aircraft power generator and an output coupled to an aircraft electrical load. A shorting switch is coupled to the input of the CPD. The shorting switch, when closed, provides a fault current path that returns to the aircraft power generator and avoids passing through the CPD and the aircraft electrical load. A controller, based upon the voltage measurements from one or more voltage sensors and current measurements from at least one current sensor selectively opens and closes one or more of the CPD and the shorting switch.

The invention relates to the field of unmanned aerial vehicle motor service life prediction, and discloses an unmanned aerial vehicle motor service life test method, which comprises the following steps: collecting motor data in real time through temperature, vibration, current and voltage sensors, carrying out cleaning, denoising and standardization processing, analyzing motor characteristics by adopting physical modeling, extracting parameters such as damage rate, temperature and load, and calculating the service life of the unmanned aerial vehicle motor. According to the method, historical data and physical modeling features are combined, an LSTM deep learning model is constructed for time sequence training, the remaining service life RUL is predicted, feature fusion is carried out, the prediction precision is improved, the health state of the motor is evaluated according to a prediction result, maintenance suggestions are provided, the model is optimized and fed back, and the prediction method is dynamically adjusted. According to the technical scheme of fusing physical modeling and the deep learning LSTM network, high-precision prediction of the service life of the motor is realized, the intelligent degree of data processing is improved, and the adaptability of the model to a complex operation environment is enhanced.

The invention relates to the technical field of frequency converter correction, in particular to a frequency converter direct-current bus correction method and system based on dynamic voltage feedback, and the method specifically comprises the steps: dynamically controlling the activation mode of a voltage sensor array according to a fluctuation state; constructing a direct-current bus voltage deviation model containing dead-zone compensation voltage and a voltage ripple frequency spectrum model containing PWM carrier sideband harmonic waves; respectively obtaining a first adjustment parameter and a second adjustment parameter; and generating a zero-sequence voltage injection instruction according to the second adjustment parameter, and implementing direct-current bus correction control by dynamically adjusting a zero-sequence voltage injection ratio. The problem that in the prior art, the system stability and the device service life are seriously restricted due to the risks of correction mismatch, harmonic amplification and even capacitor overheating of the direct current bus voltage under the dynamic working condition is solved.

The invention belongs to the technical field of battery management systems, and particularly relates to a battery state-of-charge estimation method for resisting a voltage sensor fault, which comprises the following steps: S1, data acquisition and system initialization; s2, state prediction; s3, measurement updating and online compensation are carried out; and S4, recursive circulation is carried out. According to the method, the direct-current bias quantity generated by a voltage sensor due to zero drift is widened into a state variable of a battery model, and the state variable, ohm internal resistance, polarization internal resistance, polarization voltage and charge state of a battery jointly form an expansion state vector; and performing real-time recursive estimation on the extended state vector by adopting an unscented Kalman filtering algorithm, and simultaneously obtaining an estimated value of the offset of the sensor and an estimated value of the SOC of the battery subjected to deviation compensation. Through combination of state extension and unscented Kalman filtering, fault bias of the voltage sensor can be identified and compensated online, non-Gaussian noise interference is effectively suppressed, and accuracy and robustness of battery SOC estimation in a complex industrial environment are remarkably improved.

The invention relates to an unmanned aerial vehicle zero-value insulator live detection device and method, an execution module comprises an AI image recognition unit and a detection probe, the detection probe integrates a voltage sensor and a resistance sensor and supports two modes of live resistance detection and distributed voltage detection, the AI image recognition unit is adjacent to the root of the detection probe, and the AI image recognition unit is adjacent to the root of the detection probe. The image acquisition module is used for acquiring insulator steel cap images and outputting positioning signals; the controller mainboard is electrically connected with the detection probe, the rotating mechanism and the AI image recognition unit through shielding cables, and the controller mainboard is used for receiving a positioning signal of the AI image recognition unit, receiving voltage detection data and / or current detection data transmitted by the detection probe, processing the detection data and obtaining a detection result of the state of the insulator. According to the invention, a dual-mode cooperation mechanism of'distributed voltage preliminary screening + charged resistance verification 'is adopted, and AI automatic positioning and mode automatic switching functions are combined, so that the detection efficiency is remarkably improved.

The invention discloses a submarine cable interlayer fault detection method and system for a submarine cable grounding system, and a medium. The method comprises the following steps: S1, pre-installing a power frequency current sensor, a power frequency voltage sensor and a traveling wave sensor on a sheath layer and an armor layer of landing sections at two sides of the high-voltage alternating-current submarine cable grounding system; the method comprises the following steps: extracting current and voltage signal data of a fault state through a power frequency current sensor, a power frequency voltage sensor and a traveling wave sensor, and carrying out data preprocessing including detection cleaning, data interpolation and data normalization on the current and voltage signal data; according to the method, fault codes are obtained through data collection, preprocessing, feature fusion, training learning and coding reconstruction and classification, and accurate fault detection is carried out on submarine cable interlayer faults through the fault codes.

The invention discloses a differential non-intrusive voltage measurement method based on a charge simulation method, and relates to the technical field of voltage sensor measurement, and the method comprises the steps: obtaining the distance from a plurality of sensors to a simulation line charge; wherein every two sensors form a double-layer differential structure; the simulated line charge is located in the center of the wire; based on each double-layer differential structure, determining a corresponding field-source decoupling relational expression; based on an electromagnetic formula, obtaining a relational expression between the wire surface voltage and the simulated line charge in the single power transmission line model; determining a single line voltage inversion expression based on the field-source decoupling relational expression and the relational expression of the wire surface voltage and the simulated line charge in the single power transmission line model; determining the number of single-line voltage inversion equations based on the single-line voltage inversion expressions and the number of sensors; and based on a plurality of single-line voltage inversion equations, calculating to obtain a voltage solution with the minimum overall error. According to the invention, the overall anti-interference performance of voltage inversion can be improved.

The invention discloses a charging facility fault automatic diagnosis and repair system and method, and the system comprises a voltage sensor, a current sensor, a temperature sensor, a control module, an alarm module, and an upper computer, and the voltage sensor, the current sensor, and the temperature sensor are connected with the control module through wires. The control module is connected with the alarm module and the upper computer through wires and is in signal connection with the power supply module. Potential fault risks of the charging equipment can be found in time, automatic repairing is rapidly achieved, the reliability and operation efficiency of the charging equipment are effectively improved, and manual intervention requirements are reduced.

The invention discloses a multimodal transport cargo transportation state monitoring system based on a standardized intelligent tray group. The system comprises a modular tray group composed of a main control tray and at least one functional tray; the main control tray is integrated with an edge calculator, an RFID reader-writer, a temperature and humidity sensor and a power supply module; the functional tray comprises a strain sensor and an acceleration sensor; the tray groups are rigidly connected through electromagnetic lock catches, and a voltage sensor is arranged to monitor the connection state; the tray group transmits data through a mixed communication channel; LoRa wireless communication is adopted by default, and magnetic attraction wired connection is switched when the packet loss rate is greater than 1%; after being preprocessed by the edge calculator, the data are encrypted by the Beidou system and uploaded to the background server; the background server executes overload and unbalanced load analysis, vibration grade evaluation, environmental risk early warning and lock catch state monitoring; and triggering a user side to give an alarm when an exception is detected. The safety monitoring problem of goods transportation is effectively solved, the transportation safety is improved, and the accident risk is reduced.

The invention discloses a rapid screening method for battery cells. The method comprises the following steps: 1) constructing an OCV attenuation database under different battery cell SOC and warehouse temperature T; 2) establishing a dynamic compensation model by using the attenuation database; 3) calculating a theoretical attenuation value delta OCVthetical of the battery cell through a dynamic compensation model, and comparing the theoretical attenuation value delta OCVthetical with an actually measured attenuation value delta OCVactual of the battery cell to judge abnormality; the invention further discloses a rapid screening system for the battery cells, the rapid screening system is used for achieving the method, and the rapid screening system comprises a temperature sensor, a voltage sensor, an SOC estimation module, an edge calculation terminal and a database server. According to the invention, the inventory cell detection cost can be significantly reduced, and reliable data support is provided for cell echelon utilization.

The invention provides a digital non-contact alternating-current voltage sensor and a voltage measuring method, the sensor comprises an open-type alternating-current voltage probe, a sensing assembly based on the capacitive voltage dividing principle in the probe converts high voltage on a wire into a first voltage analog signal, and an external grounding shielding layer provides anti-interference protection. Signals output by the probe are sent to the signal acquisition module, a signal conditioning circuit in the signal acquisition module firstly filters, blocks and amplifies the signals, and second voltage analog signals easier to process are generated. And then, the main control unit integrated with an analog-to-digital converter converts the signal into a digital sampling value, and finally, the communication unit outputs a measurement result in a digital signal form. According to the sensor, through non-contact measurement and full-digital processing, safe and convenient alternating current high voltage detection is realized, and stable and anti-interference digital signals can be output.

The invention discloses a fault monitoring and positioning method for a high-voltage drop-out fuse, and relates to the technical field of power equipment fault monitoring, and the method comprises the steps: obtaining original monitoring sequences corresponding to current and voltage sensors disposed at upper and lower ports of a target fuse; activating a working mode recognizer to execute working mode recognition of the target fuse, establishing a global mode label, executing adaptive matching of a mode fingerprint database, and establishing a standard comparison fingerprint with a trust identifier; establishing residual spectrum characteristics; and establishing a fault discrimination vector, carrying out space fault positioning by using the fault discrimination vector, and generating a fault positioning result. According to the invention, the technical problems of insufficient fault monitoring and positioning accuracy, lack of visual presentation capability and low monitoring and positioning efficiency of the high-voltage drop-out fuse in the prior art are solved, and accurate positioning and visual presentation of the fault of the high-voltage drop-out fuse are realized. And the accuracy and efficiency of fault monitoring and positioning are improved.

An apparatus and method for limiting inrush current to an end device provides an alternating current (AC) to the end device via a power cord including first and second current carrying conductors. A voltage sensor enclosed by a housing attached to a power cord and connected to the conductors senses an input voltage. A current sensor within the housing senses an inrush current via the first conductor. A microcontroller unit (MCU) within the housing receives the sensed input voltage and inrush current. Based on the sensed input voltage, the MCU determines a voltage drop across a negative temperature coefficient (NTC) thermistor serially connected (with a switching device) to the first conductor. When the sensed inrush current and / or the sensed input voltage reaches a threshold level, the MCU engages the NTC thermistor to limit inrush current by opening the switching device.

The utility model relates to the technical field of electric power, in particular to a solid-sealed polar pole, which is applied to a medium-voltage power grid and used for extracting current signals, voltage signals and a power-taking power supply from the medium-voltage power grid, and further comprises a vacuum arc-extinguishing chamber, the transition piece and the spring contact finger are movably connected to the output end of the vacuum arc-extinguishing chamber; the conducting rod is connected with the spring contact finger and extends to the wire outlet side of the medium-voltage power grid; the current and voltage sensor group comprises an incoming line side voltage sensor of which the high-voltage end is connected with the incoming line side of the medium-voltage power grid and the low-voltage end is grounded; the high-voltage end of the wire outlet side voltage sensor is connected with the conducting rod, and the low-voltage end is grounded; the zero sequence current sensor and the phase current sensor are sleeved on the conducting rod; the high-voltage low-temperature-drift ceramic capacitor is adopted, one-time integral solid sealing is achieved, meanwhile, the current and voltage sensor set and the capacitor electricity-taking power source set are integrated, one-time integral solid sealing is achieved, the manufacturing process is simplified, and the insulation reliability is improved.

The invention discloses a power distribution device operation state visual monitoring system based on Internet of Things access, which comprises a sensing layer, a network layer, a platform layer and an application layer, and is characterized in that the sensing layer comprises a voltage sensor, a current sensor, a temperature sensor and a vibration sensor, and the network layer comprises a data transmission module; the platform layer comprises a data preprocessing and feature extraction module, the output end of the voltage sensor is unidirectionally and electrically connected with a voltage data acquisition module, and the output end of the current sensor is unidirectionally and electrically connected with a current data acquisition module. The sensing layer realizes multi-dimensional accurate data acquisition through various sensors and corresponding acquisition modules, fault missing detection is avoided, the Internet of Things communication technology of the network layer is combined with the encryption module, stable and safe data transmission is ensured, the platform layer efficiently processes data through an edge calculation module and the like, the energy-saving control module realizes consumption reduction, and the system is suitable for large-scale popularization and application. And an application layer visual interface visually presents a result.

The invention discloses a photovoltaic cell maximum power point tracking method based on perturbation observation and fuzzy control. The method comprises the steps that current and voltage values of a photovoltaic cell at the current moment are collected through a current sensor and a voltage sensor; respectively subtracting the current and voltage at the current moment from the current and voltage at the previous moment to obtain a current and voltage difference value between the current moment and the previous moment, and further calculating a power difference value; taking the power difference value and the voltage difference value as input of a fuzzy controller, and performing fuzzy processing; performing fuzzy reasoning on the fuzzified power and voltage difference value and the output variable according to a predefined fuzzy rule; and deblurring the reasoning result to obtain a required duty ratio change value, and superposing the required duty ratio change value with the initial duty ratio value to obtain a final duty ratio value. According to the invention, balance between dynamic response and steady-state precision is realized, an innovative solution is provided for efficient photovoltaic energy conversion in a complex environment, and full-working-condition detection of a photovoltaic IV tester is guaranteed.

The invention relates to a visual on-load voltage regulation tap switch control system, device and medium, which comprises a single chip microcomputer control circuit, the single chip microcomputer control circuit is connected with a signal processing circuit and a power supply circuit, and the signal processing circuit is connected with a voltage zero cross detection circuit, a voltage sensor and a data acquisition unit. The voltage zero-cross detection circuit, the voltage sensor, the data acquisition unit and the power supply circuit are all connected with the isolation reduction transformer, and the isolation reduction transformer is connected with the low-voltage side voltage of the distribution transformer; the single-chip microcomputer control circuit is further connected with a switch position sensor, a communication circuit, a switch drive circuit and a thyristor trigger circuit. The communication circuit is in communication connection with a remote computer through an RS485. The method has the advantages of realizing automatic voltage regulation conversion, stabilizing voltage, accurately setting visual parameters and realizing non-impact voltage regulation.

A battery power system includes a battery, a sensor suite, and a controller. The sensor suite includes a current sensor, a voltage sensor, and a temperature sensor. The controller is operable to use current signals from the current sensor and voltage signals from the voltage sensor, along with an equivalent circuit model (ECM), to determine an estimated open-circuit voltage of the battery at different points in time. The controller uses the open-circuit voltage and temperature to determine the ECM's state of charge (SOC) of the battery at different points in time via a calibrated SOC map. The controller also calculates a sensor gain value using the ECM-based SOC and the coulomb counting-based SOC (both at different points in time). When the sensor gain value exceeds a predetermined fault threshold, a control action is executed with respect to the battery, including generating a fault notification signal indicating a fault in the current sensor.

The invention discloses a self-adaptive control method, system and device for inertia coefficients of a network-forming converter and a storage medium, and relates to the technical field of power electronic converter control, and the method comprises the steps: collecting the DC side voltage of a converter in real time through a voltage sensor, and calculating the deviation between the DC side voltage and a DC voltage reference value; the output angular velocity deviation of the converter is obtained, the inertia coefficient of the converter is dynamically adjusted through a nonlinear function in combination with the direct-current side voltage deviation, and self-adaptive adjustment of control parameters of the converter is achieved; the dynamically adjusted inertia coefficient of the converter is substituted into a converter control link in real time, and the output characteristic of the converter is changed, so that the output performance of the converter is optimized; self-synchronization grid connection can be realized, the anti-interference capability of the system is enhanced, the converter adapts to complex working conditions, virtual inertia is provided for a power grid, the frequency of the power grid is stabilized, and the operation stability of the grid-forming converter and the new energy accepting capability of the power grid are improved.

Electrical storage system with: an electrical storage device (10); a load (20); a line (PL) configured to connect the electrical storage device (10) and the load (20); a relay (SMR-G) that is provided in the line (PL); a capacitor (C11) which has one end connected to the electrical storage device (10) and the other end connected to a ground; a voltage sensor (21) configured to detect a voltage value of the capacitor (C11); a first insulation resistance (RB) which is set up between the electrical storage device (10) and the ground; a second insulation resistor (RL) which is installed between the load (20) and the ground; a first current path (L1) which includes the first insulation resistance (RB); a second current path (L2) comprising the conductor (PL) and the second insulation resistance (RL); and a control unit (50) that is configured to (a) Controlling ON and OFF of the relay (SMR-G), and (b) Determine that the relay (SMR-G) is blocked in an ON state if the voltage value is substantially equal to a second voltage value in a case where control to turn off the relay (SMR-G) is carried out, where a first resistance value is higher than a second resistance value, the second voltage value is higher than a first voltage value, the first resistance value is a resistance value of the first insulation resistance (RB), the second resistance value is a resistance value of the second insulation resistance (RL), the first voltage value is a voltage value when a discharge current of the electrical storage device (10) flows to the capacitor (C11) in the first current path (L1), the second voltage value is a voltage value when the discharge current of the electrical storage device (10) flows to the capacitor (C11) in the second current path (L2).

The invention discloses a transmission tower angle steel electromagnetic pulse fastening system, which belongs to the technical field of transmission tower angle steel fastening, and is characterized in that a track subsystem is rigidly connected with an operation table to realize movement and position adjustment in an operation environment; the charging control platform comprises a power supply device, a capacitor, an SCR power voltage regulator and voltage sensors, the power supply device is connected with the capacitor, and the voltage sensors are connected to the two ends of the capacitor; the charging control platform regulates and controls the charging process of the capacitor through the SCR power voltage regulator; the electromagnetic pulse generation subsystem is connected with the charging control platform, and the electromagnetic pulse generation subsystem is used for generating electromagnetic pulses to achieve fastening operation of angle steel of the power transmission tower; the monitoring feedback subsystem is used for monitoring the operation state of the transmission tower angle steel electromagnetic pulse fastening system in real time. The electromagnetic pulse technology is combined with the field of angle steel reinforcement, and the problems that existing electromagnetic pulse crimping equipment is inconvenient to move, depends on an external power supply, is inaccurate in charging control, and is difficult to monitor the running state in real time are solved.

The invention provides an intelligent stamping die failure monitoring system and method. The intelligent stamping die failure monitoring system comprises a data acquisition layer, a data processing layer and a data processing layer, wherein a voltage sensor is used for detecting voltage fluctuation of a stamping machine, a temperature sensor is used for detecting the temperature of cooling liquid of the stamping machine, a vibration sensor is used for detecting the machine table vibration frequency of the stamping machine, and a photoelectric encoder is used for acquiring stamping frequency data; aiming at the to-be-processed steel belt, arranging a magnetic flux detection device to detect the magnetic flux change of the steel belt; the data collected by the data acquisition layer is timestamped and then transmitted to the data storage layer, the mold failure is monitored by introducing magnetic flux parameters, a failure model is constructed, and the mold failure condition is monitored by setting a three-level early warning mechanism.

The invention relates to the technical field of power electronics and battery management, and provides a mobile power adapter and a dynamic power distribution and safety monitoring method thereof. The method comprises the following steps: acquiring the connection state of an external power supply, if the external power supply is detected to be connected, entering an adapter mode, and supplying power to equipment by a lithium battery pack through a bidirectional DC-DC conversion circuit; in the adapter mode, load data of an equipment charging channel, a self battery charging channel and two independent output interfaces are monitored in real time through a power sensor, and the electric quantity of equipment, the electric quantity of a lithium battery pack and the power of an external power supply are obtained; running data of a lithium battery pack and an output interface are collected in real time through a built-in temperature sensor, a built-in voltage sensor and a built-in current sensor, and the risks of over-charging, over-discharging, short circuit and overheating are detected in real time in combination with an abnormal state recognition algorithm; periodically detecting the internal resistance of the lithium battery pack, judging the aging degree of the battery according to the change of the internal resistance, and dynamically reducing the charging current based on the aging degree of the battery.

A submerged arc welding system includes a welding power supply, a welding wire feeder, a control unit for the welding power supply and the welding wire feeder, and a voltage sensor to detect voltage between the tip of the welding wire and a workpiece. Under the control of the control unit, the wire feeder feeds the welding wire at an initial feed speed at start of welding. Further, when the tip of the welding wire shorts to the workpiece, the wire feeder stops the feeding of the welding, and the welding power supply starts outputting welding current. Further, when a detection voltage detected by the voltage sensor reaches or exceeds a voltage threshold, the wire feeder starts feeding the welding wire at a welding feed speed for welding.

A battery pack includes cells, a pressure contributing component contributing to a change in pressure in the battery pack, at least one pressure sensor configured to detect the pressure in the battery pack, and at least one voltage sensor configured to detect a voltage of the cells. A thermal chain determination method includes detecting the pressure in the battery pack, detecting the voltage of the cells, determining that the pressure in the battery pack is abnormal when an amount or rate of change is larger than a predetermined value, determining that the voltage of the cells is abnormal when an amount or rate of change in the detected voltage is larger than a predetermined value, or when an absolute value of the voltage of the cells is smaller than a predetermined value, and determining that a thermal chain occurs when both the pressure and the voltage are abnormal.