352 results about "Electric arc discharge" patented technology

The invention discloses a power transformer arc discharge multi-parameter detection simulation platform and a fault diagnosis method, and relates to the technical field of power system equipment state monitoring and fault diagnosis. The platform comprises a transformer body, a replaceable discharge module, a multi-parameter sensing unit and a signal processing and diagnosis module, and can truly reproduce various typical arc discharge faults of a needle plate, an air gap, a creeping surface, turn-to-turn and the like. The sensing unit is integrated with ultrahigh frequency and ultrasonic sensing probes, high-frequency current and voltage sensors, optical fiber temperature / pressure / strain sensors and the like, so that synchronous acquisition of multi-physical field signals is realized. According to the diagnosis method, through wavelet denoising and multi-dimensional feature extraction, a feature vector of multi-state parameter fusion in the process from partial discharge to arcing is constructed, and accurate classification of fault types is realized by using a support vector machine (SVM) model. The diagnosis method has high accuracy and early warning capability, effectively overcomes the limitation of single parameter diagnosis, and provides reliable technical support for transformer fault research and intelligent operation and maintenance.

The invention provides embedded metal fullerene and a preparation method thereof. The preparation method comprises the following steps: mixing a metal source and graphite powder, and filling a hollow graphite rod with the mixture to prepare an anode; the electrode is installed at the anode end of an electric arc furnace, and on-line activation is conducted through anode and cathode short-circuit current under the inert atmosphere; then carrying out arc discharge under specific air pressure and current, and collecting generated carbon ash; performing ultrasonic extraction by using an organic solvent to obtain a fullerene crude extracting solution; and finally, performing multi-stage separation and purification by high performance liquid chromatography, and performing primary and fine separation by sequentially adopting preparative and semi-preparative chromatographic columns to obtain a high-purity product. According to the method, a complete technical path capable of efficiently and controllably preparing the ultra-high-purity embedded metal fullerene is formed through a synthesis process integrating online activation and accurate atmosphere regulation and control and a multi-stage gradient chromatography purification strategy, and a solid foundation is laid for application of atomic-scale accurate materials in the frontier fields of quantum devices and the like.

The invention discloses a method for calculating static pressure generated by arc discharge in a transformer oil tank, and the method comprises the steps: obtaining an expansion coefficient c of the transformer oil tank; electric arc time-varying power P (t) and energy W (t) of electric arc discharge in the transformer oil tank are obtained through calculation; the arc discharge product temperature T of arc discharge in the transformer oil tank is obtained; a gas space V0 existing in the transformer oil tank is measured, and the amount Vg of gas dissolved in oil is calculated according to the solubility kh of characteristic gas generated by the electric arc in the oil; and calculating static pressure p generated by arc discharge in the transformer oil tank according to a static pressure calculation formula.

The invention belongs to the technical field of electric power, and discloses an isolating switch which comprises a base, a second insulating column fixedly mounted at the top of the base, a static contact pad fixedly mounted at the top of the second insulating column, and a disconnecting link assembly hinged to the static contact pad, and the butt joint assembly is fixedly arranged at the top of the base. According to the invention, the disconnecting link main body is driven by an electric motor or a hand wheel to rotate by taking the hinged part of the disconnecting link main body and the static contact pad as a center shaft, so that the butt joint piece falls into the top of the moving contact pad, the butt joint piece pushes the two sliding frames, the conductive piece and the butt joint toothed plate to move relatively, and the butt joint toothed plate is engaged with racks on two sides of the butt joint piece; the contact area of the butt-joint piece and the butt-joint toothed plate is increased through meshing of the multiple racks, the phenomenon of deformation caused by thermal expansion and cold contraction is avoided, meanwhile, the butt-joint piece and the butt-joint toothed plate are in surface contact all the time, the effective conductive section is guaranteed, local overheating and arc discharge are avoided, and the reliability of circuit on-off is guaranteed.

The invention relates to the technical field of pulse state recognition, in particular to an electric spark discharge pulse state recognition and control system and method.The electric spark discharge pulse state recognition and control method comprises the following steps that gap voltage is obtained, and whether the gap voltage is rising edge voltage or not is judged; comparing the gap voltage which is judged to be the rising edge voltage with a preset threshold voltage; when the gap voltage is the same as any one of the preset threshold voltages, a trigger state identifier is set to be 1, and counting is started from a preset value A1; when any one of counting stopping conditions is met, counting is stopped, the state identifier is reset, and the counting value is returned to the preset value A1; calculating delay time between two time points of counting starting and counting stopping; judging the delay time and outputting a judgment result; and performing control according to the judgment result. According to the invention, based on the pulse voltage threshold and the time characteristic, the short-circuit arc pulse and the arc discharge pulse are rapidly and accurately identified.

The invention relates to a deicing method, system and device based on gas-liquid discharge mode conversion and intelligent regulation, and the method comprises the steps: monitoring and predicting an icing state, and adjusting the output of a multi-gear adjustable power supply according to a prediction result, so as to generate weak spark discharge; when the icing condition is met, the needed energy is calculated according to the monitoring data to adjust the output of the multi-gear adjustable power supply so as to generate dielectric barrier glow discharge, and the discharge parameter is dynamically adjusted to maximize the strong heat input effect; the forming time and position of a gas-liquid mixture cavity under the condition of dielectric barrier glow discharge are predicted in real time by introducing a thermodynamic principle and an ice layer melting model, and after the cavity is detected to be formed, the optimal opportunity and energy of strong arc discharge are determined according to cavity parameters; therefore, the output of the multi-gear adjustable power supply is adjusted to generate strong arc discharge, and the cavity of the gas-liquid mixture is induced to expand and break, so that the ice layer falls off. The invention provides a more efficient, environment-friendly and reliable deicing solution.

The invention discloses a spectral analysis method and device for an arc discharge decomposer of a mixed environment-friendly gas, and the method comprises the steps: injecting the mixed environment-friendly gas into an arc discharge device, and setting discharge parameters; the mixed environment-friendly gas comprises perfluoroisobutyronitrile and carbon dioxide; the discharge parameters at least comprise discharge current and discharge voltage; controlling the arc discharge device to perform arc discharge so as to decompose the mixed environment-friendly gas to generate a decomposer; collecting decomposed products through a gas collecting device, and pretreating the decomposed products; analyzing the preprocessed decomposer through a spectrum instrument to obtain spectrum data; the spectral data at least comprises wavelength, intensity and peak value; acquiring a characteristic spectral line of the decomposer according to the spectral data; determining the type and the measurement concentration of the decomposer according to the standard database and the characteristic spectral line; and checking and correcting the measured concentration of the decomposer. According to the technical scheme provided by the invention, the reliability and the accuracy of decomposition product detection are improved.

The invention discloses a safe operation method and an equipotential system for an aerial operation robot, and the method is characterized in that the safe operation method comprises the following steps: a drainage guide rod of the equipotential system is arranged at the bottom of a foot stool and is connected with an overhead line when approaching the overhead line, and a tensioning reset mechanism keeps the drainage guide rod to be in contact with the overhead line during landing; it is ensured that the aerial work robot and the overhead line are in an equipotential state in the landing process, and damage to components on a machine body of the aerial work robot caused by arc discharge is avoided; the traveling wheels form stable equipotential after riding to the overhead line, the driving mechanism drives the drainage guide rod to be separated from the overhead line, and the drainage guide rod is limited by the limiting device, so that electric arc and fire caused by long-time friction between the drainage guide rod and the overhead line during operation movement are avoided; limiting is relieved after operation, the tensioning reset mechanism enables the drainage guide rod and the overhead line to recover connection and keep connection, the flying-away aerial operation robot and the overhead line are in an equipotential state, and the equipotential system is closed or dormant after the flying-away aerial operation robot is separated from the overhead line.

The invention provides a directional ultra-short strong field electromagnetic pulse generation device, a plasma channel is formed through laser targeting gas and ultra-short strong field electromagnetic pulses are generated, the device comprises a high-power laser, a laser focusing module, a gas target module and a vacuum cavity, the high-power laser is used for generating femtosecond laser pulses and emitting the femtosecond laser pulses into the vacuum cavity; the laser focusing module is arranged in the vacuum cavity and is used for focusing femtosecond laser pulses generated by the high-power laser onto the gas target; the gas target module is arranged in the vacuum cavity and used for generating a high-density gas target and spraying the high-density gas target upwards, and a gas spraying opening of a gas target nozzle is located below the laser focus and can be adjusted in an electric control mode. According to the invention, escape electrons with charge quantity larger than that of a solid target and a low-density gas target can be generated, and laser forms arc discharge similar to thunder and lightning cloud in near-critical density plasma to generate EMP, so that electromagnetic radiation which is stronger than that of the solid target and far better than that of a common gas target can be generated.

The invention discloses a method and system for calculating the average temperature of arc discharge products in a transformer oil tank, and the method comprises the steps: carrying out an arc discharge experiment in a sealed oil-filled tank body of transformer oil, and measuring the arc discharge voltage, current and pressure waveform, the volume of the arc discharge products at room temperature, and the corresponding pressure in the oil tank; the time-varying temperature T (t) of the discharge product during arcing is obtained by calculating the discharge static pressure pL (t) obtained by measurement; calculating the temperature of a discharge product after arc quenching; and obtaining an average temperature change curve of the discharge product at different time stages based on the time-varying temperature of the discharge product during arcing and the average temperature of the discharge product after arc quenching.

Provided are an uninterruptible power supply (UPS), a method and an apparatus for soft starting the UPS, and a controller. In the UPS, an inverter circuit is provided with three-phase output terminals, and two output terminals of a pre-charge circuit are electrically connected to output terminals of any two phases, respectively. The UPS charges a bus capacitor through an energy storage operation and a freewheeling operation, so that a voltage of the bus capacitor is greater than a peak value of a mains power. When the mains relay is powered on, a voltage of an end of the mains relay that is electrically connected to the mains power is lower than the voltage of the bus capacitor. Due to limitation of a conduction direction in a rectification circuit, no inrush current occurs, thereby reducing arcing of relay contacts and improving stability of the UPS during a power-on process.

The invention relates to the technical field of power system fault simulation, and discloses a DC fault simulation method for a medium-voltage DC system, and the method comprises the steps: constructing an equivalent circuit containing line distribution parameters, and representing the transmission characteristics of resistance, inductance and capacitance per unit length, a linear mathematical model of arc voltage and arc length is established based on arc discharge experiment data, a dynamic resistance curve is generated in combination with an arc length time increase function, an initial value and a change rate of dynamic resistance are extracted as characteristic parameters, and a mapping relation table of the characteristic parameters with metallic short circuit and mild / severe arc faults is established. And according to a target fault type, matching a dynamic resistance parameter, injecting the dynamic resistance parameter into an equivalent circuit, solving a differential equation containing a time-varying resistor, and outputting a high-fidelity DC fault current signal. The method solves the problem that static resistance simulation cannot reproduce arc dynamic characteristics, and significantly improves the accuracy of fault simulation.

The invention provides a spark discharge device and a spark discharge accurate control method, and relates to the technical field of spark discharge. The device comprises a pair of spark electrodes, a rotary switch, a capacitor and a power supply, wherein a gap exists between working ends of the spark electrodes; the spark electrode, the rotary switch and the capacitor are connected in series to form a discharging loop, and the capacitor and the power supply are connected in series to form a charging loop; the rotary switch comprises a rotatable rotor and a toothed bar connected with the rotor; a contact is arranged in the discharge loop, and when the contact is in contact with the toothed bar, the discharge loop is conducted. According to the invention, the discharge loop is rapidly switched on and switched off through the rotary switch, various parameters of spark discharge can be accurately and stably controlled, so that the spark discharge is not influenced by the environment, such as spark breakdown voltage, discharge frequency and the like, and the spark discharge can be prevented from being converted into corona, glow or arc discharge, for example, the spark discharge can be normally generated under low air pressure.

The invention relates to a layered cathode structure based on functional layer-buffer layer alternate distribution and a rapid trial-manufacturing method thereof, and belongs to the technical field of machining, the layered cathode structure comprises a functional structure surface layer and a matrix, and the functional structure surface layer is further formed by stacking and alternately arranging a plurality of sub functional layers and buffer layers. In actual service, a refractory oxide layer is generated in situ on the basis of the functional layer made of the thermochemical material, self-protection is completed, and electrons are emitted to support arc discharge; and the buffer layer is made of a nanocrystalline material with high plastic deformation capacity, so that the thermal stress of the functional layer can be released through proper deformation of the buffer layer, and meanwhile, cathode spot migration can be accelerated when the buffer layer is in contact with a cathode arc so as to slow down cathode burning loss. Through the synergistic effect of the functional layer and the buffer layer, the problems of cracking, splitting and coating falling caused by plasma discharge shock heating and shock cooling of the layered cathode in application scenes such as electric spark machining hole making and electric arc welding are solved, meanwhile, the ablation uniformity is improved, and the ablation rate is reduced.

Methods of monitoring arcing in a process chamber, processing chambers and monitoring apparatus are described. At least one of the angular or radial position of a magnetron is determined in the chamber relative to a reference location on a surface of the substrate using positional information from one or more motors. An arcing profile is generated comprising a plurality of arcing states measured based at least on the determined angular and / or radial position of the magnetron.

The embodiment of the invention discloses a method, a device and a system for identifying abnormal discharge of a sulfur hexafluoride circuit breaker. The method comprises the following steps of: receiving a gas pressure data sequence of the sulfur hexafluoride circuit breaker, which is acquired and uploaded by a sulfur hexafluoride density relay in real time; drawing a gas pressure time curve of the sulfur hexafluoride circuit breaker according to the gas pressure data sequence; determining a communication mode of performing data communication with the sulfur hexafluoride density relay at the current moment, and obtaining a curve change extreme value of the gas pressure time curve based on the communication mode; and comparing the curve change extreme value with a preset pressure change threshold value, and when the curve change extreme value is greater than the preset pressure change threshold value, judging that abnormal discharge exists in the sulfur hexafluoride circuit breaker. Whether abnormal discharge occurs in the sulfur hexafluoride circuit breaker or not is judged by monitoring the gas pressure sudden increase phenomenon during arc discharge in the sulfur hexafluoride circuit breaker, and the problem that a mechanical density relay cannot monitor an abnormal discharge event in the circuit breaker is solved.

The invention provides an electric arc discharge detection method of a parallel energy storage battery unit and a related product. A plurality of energy storage battery units are connected in parallel, microphones are arranged in the energy storage battery units, battery management systems of the energy storage battery units are configured to detect end currents and end voltages of the energy storage battery units, and the electric arc discharge detection method comprises the steps that the battery management systems judge whether the end currents and the end voltages have electric arc discharge characteristics or not; if yes, the battery management system controls the energy storage battery unit to be disconnected; collecting a sound signal detected by the microphone in the same time period when the electric arc discharge characteristic appears; identifying whether the sound signal has a sound feature in an electric arc generation state or not; and if yes, determining that the energy storage battery unit has an electric arc discharge event. According to the scheme provided by the invention, the electrical arcing identification of the sound signal dimension is carried out according to the sound signal detected by the microphone in the time period when the electrical arcing characteristic appears, so that the judgment is carried out by utilizing the multi-dimensional data, the identification accuracy is improved, and the false detection and the missing detection are reduced.

The present invention provides a lower electrode assembly, a mounting method thereof and a plasma processing device in which the lower electrode assembly is located. The gap between the dielectric ring and the base is divided into two or more gaps by cooperating with the dielectric ring and the base, and a protective ring is arranged between the dielectric ring and the base, and a protective layer is arranged on the outer side of the base, so as to avoid the plasma above the substrate and the focusing ring from leaking into the gap between the base and the edge ring assembly, prevent the plasma from corroding the base, reduce the possibility of arc discharge in the lower electrode assembly, and effectively ensure the safety of the use of the lower electrode assembly.

The present invention discloses a liquid-gas phase change device based on arc discharge excitation and an excitation method thereof. The liquid-gas phase change device includes a primary chamber and a plurality of phase change units arranged on the primary chamber and communicated with the primary chamber; each phase change unit includes a high-voltage power generation module, a first discharge electrode, a second discharge electrode and a heating tooling. The second ends of the first discharge electrode and the second discharge electrode respectively insert into the cavity of the heating tooling from two opposite connection ports of the heating tooling and are aligned; the first ends of the first discharge electrode and the second discharge electrode are respectively connected to the positive output end and the negative output end of the high-voltage power generation module. The present invention can realize the rapid heating of the liquid medium, significantly improve the heating efficiency and the gaseous phase change reaction rate, and further improve the energy conversion efficiency.

The invention discloses a fault detection method and system based on lightning protection device performance data, and relates to the technical field of fault detection, and the method comprises the steps: capturing the airflow velocity and airflow pressure deviation of a multi-crack outlet of a lightning protection device under the impact of a high lightning current in real time, and collecting the arc length data of an outlet point of the lightning protection device, and the temperature and instantaneous arc resistance of the thermocouple induction arc column are calculated. According to the method, the normalized airflow energy density and arc energy density features are combined into the joint feature sequence, so that the coupling relationship between the airflow performance and the arc discharge behavior of the lightning protection device can be captured, and the global detection state of slow evolution and instantaneous mutation of the equipment fault is realized; the lightning stroke threat intensity can be independently reflected by defining the dynamic risk index, lightning stroke threat propagation and topological network characteristics are combined in combination with lightning protection device performance detection data, and therefore transmission effect modeling of the lightning stroke dynamic risk is achieved.

A coating system for coating a substrate by an arc discharge comprises a target holder for holding a target; a substrate holder arranged along an emission axis behind the target holder for holding a substrate to be coated by the target; an anode for generating an arc discharge between the target holder and the anode, wherein the anode is arranged between the target holder and the substrate holder; an manipulation system arranged along the emission axis behind the anode, which is arranged to generate an electric and / or magnetic field for influencing a plasma propagating from the target holder along the emission axis by the arc discharge. A method for generating a plasma by an arc discharge and for manipulating the plasma by a magnetic field generated by one or more than one electromagnetic coil disposed along the emission axis behind the anode.

This invention provides an electrode device having a support for engaging and holding a graphite electrode used in the manufacture of a quartz crucible via arc discharge. The electrode device is characterized in that the outermost surface layer of the support, at the portion adjacent to the graphite electrode when the support is engaged with the graphite electrode, has an anti-fouling film. Thus, an electrode device is provided that can suppress contamination from the support, shorten the lifespan of the graphite electrode, and reduce manufacturing costs.

An example of a sliding contact strip capable of suppressing frequent arc discharges is disclosed. [Solution] The sliding contact strip 1 is provided with an insulating portion 4 on the sliding contact surface 3 that has a higher electrical resistance than the conductive portion (parts other than the insulating portion 4), and the insulating portion 4 is provided only on a portion of the sliding contact surface 3 in the width direction. Therefore, the occurrence of arc discharge between the trolley wire and the insulating portion 4 can be suppressed, and even if arc discharge occurs between the trolley wire and the conductive portion 5, the continuous and frequent occurrence of such arc discharge can be suppressed. Consequently, premature damage to the sliding contact strip 1 can be suppressed.

The invention provides a system and a method for removing charges in liquid medicine, which are applied to the technical field of semiconductors. According to the invention, a small-flow liquid medicine circulation pipeline is additionally arranged on a machine table pipeline at the front end of the liquid medicine nozzle, and the liquid medicine circulation pipeline is grounded, so that as long as one path is grounded, charges in the liquid medicine in all branches can be conducted away along the path; therefore, charges in all the liquid medicine in the machine pipeline can be conducted away, the problem that when the liquid medicine nozzle sprays liquid medicine to the surface of a wafer, instantaneous high potential difference is generated, arc discharge defects are formed, and a circuit fails is solved, and the reliability, the electrical performance and the yield of products are improved. In addition, the method is simple and efficient, and is suitable for various liquid medicines, so that the method has relatively high mass production applicability.

The invention discloses a low-temperature vacuum annular electron accelerator arc reactor, which relates to the field of electromagnetism and is applied to the technology and concept of energy generation, conversion and transmission. The device is composed of a high-voltage electron gun module (1), a low-temperature vacuum annular pipe module (2), a sealing module (3), an accelerating electric field module (4), a magnet guiding module (5), a magnetic core module (6), an induction coil output module (7) and a base module (8). According to the technology and the concept, a low-temperature vacuum annular electron accelerator is used for replacing a primary coil winding of a traditional transformer, that is, the same electric field is used for circularly accelerating electrons emitted into an annular vacuum tube by an electron gun to form annular electron flow to replace the primary coil winding of the traditional transformer. When the high-speed circling electrons lose to accelerate the action of an electric field, due to the mass inertia effect of the high-speed electrons, the annular current cannot disappear immediately under the guidance of the magnetic lines of force of the fixed magnet, the magnetic flux of the magnetic core still changes, and therefore the secondary coil can still obtain corresponding arc discharge. Therefore, the inductive discharge of the secondary coil can reversely act on the energy conversion of the accelerating electric field or the electron gun, so that the energy conversion efficiency is improved, and the energy loss is reduced.

The present invention provides a substrate processing method and a substrate processing apparatus capable of suppressing the occurrence of arc discharge during an etching process. The present invention is a substrate processing method in a chamber, wherein the chamber includes: a stage for placing a substrate; an upper electrode opposed to the stage; and a gas supply port for supplying a processing gas into the chamber, and the substrate processing method includes the following a) to d). a) is a step of providing a substrate to the stage. b) is a step of supplying a first processing gas into the chamber. c) is a step of generating plasma from the first processing gas by continuously supplying a negative DC voltage to the upper electrode while continuously supplying an RF signal. d) is a step of generating plasma from the first processing gas by continuously supplying a negative DC voltage to the upper electrode while supplying a pulsed RF signal. c) and d) are alternately and repeatedly executed. In addition, the period of each execution of c) is 30 seconds or less.

The invention discloses a strong arc discharge transient impact measurement device. The device comprises a shielding box for realizing an electromagnetic shielding function; the box body and the cover plate are fixedly connected through flange turnups arranged on the periphery of the box body, and the cover plate is provided with a graphite copper sleeve. The force transmission pipe is inserted into the inner side of the graphite copper sleeve; the mounting base is a cylinder with a boss and is fixed on the inner surface of the bottom of the shielding box; the pressure sensor is sleeved on the boss of the mounting base; the insulator has an insulating property, so that insulation between the force transmission tube and the pressure sensor is realized; the shielding box is an electric conductor, and the flange flanging is connected with a loop of an external arc injection test facility; during test, an electric arc discharges between an electrode of the electric arc injection test facility and a to-be-tested piece to generate downward pressure, current flows into the shielding box from the to-be-tested piece, flows out of a flange flange of the shielding box and returns to the electric arc injection test facility, and the pressure is transmitted to the pressure sensor from the to-be-tested piece through the force transmission pipe and the insulator; the device is used for measuring the transient impact of strong arc discharge.

The present invention provides a method and system for determining the physical properties of arc discharge plasma in transformer oil, relating to the field of data processing technology. The implementation scheme comprises: performing a power-frequency arc discharge on the transformer oil to determine the initial particle concentration of each element when a plasma channel is formed in the transformer oil, and collecting the radiation light from the power-frequency arc discharge; performing spectral analysis on the radiation light, and determining the particle type, heavy particle temperature, electron temperature, and excited-state temperature of the plasma in the transformer oil based on the spectral analysis results; iteratively correcting the initial particle concentration of each element based on the particle type, heavy particle temperature, electron temperature, and excited-state temperature of the plasma in the transformer oil to obtain a target particle concentration for each element; and determining the physical properties of the plasma in the transformer oil based on the target particle concentration for each element. This method can accurately describe the physical properties of the plasma in the transformer oil.

The present invention discloses an equipotential system for unmanned aerial vehicles (UAVs) and a safe operation method. The advantages of the equipotential system are that the equipotential system includes a self-tightening drainage mechanism and a disconnecting mechanism. After the equipotential system is initialized and started, the drainage wire of the self-tightening drainage mechanism arranged at the bottom of the tripod is first connected to the overhead line to form an equipotential state. During landing, the drainage wire is passively extended to maintain good contact with the overhead line, so that the UAV and the overhead line are in an equipotential state; after the walking wheel rides on the overhead line, the drainage wire is pulled away from the overhead line by the disconnecting mechanism before operation, so as to avoid the drainage wire and the overhead line from being rubbed for a long time during operation to generate an arc and melt; before flying away after the operation, the disconnecting mechanism releases the drainage wire so that the drainage wire and the overhead line are restored to be connected; during flying away, the drainage wire automatically contracts to maintain good contact with the overhead line, so that the UAV and the overhead line are in an equipotential state, so as to avoid arc discharge and damage to the components of the UAV body; the equipotential system is closed after the drainage wire is disconnected from the overhead line.

A fault detection device (100) is provided with: a first actuator (10) and a second actuator (20) each driven by electric energy, the second actuator (20) comprising a brush DC motor; a current detection circuit (50) including a first current detection circuit (51) provided to detect a current flowing through the first actuator (10) and a second current detection circuit (52) provided to detect a current generated by arc discharge of the second actuator (20); and a failure determination unit (47) that determines whether there is a failure in each of the first actuator (10) and the second actuator (20) on the basis of the current detected by the current detection circuit (50). The current detection circuit (50) has a current detector (46) that is provided in a common section (53) of the first current detection circuit (51) and the second current detection circuit (52) and that detects a current flowing through the common section (53).