Abstract: An electrical insulating property tester includes a guaranteed voltage applying unit for applying a guaranteed voltage to a running line provided with an electrical insulating layer around an electrical conducting wire, a grounding unit arranged downstream of the guaranteed voltage applying unit, for grounding the running line to thereby remove electric charge electrostatically induced on the running line, and a test voltage applying unit arranged downstream of the grounding unit, for applying a test voltage lower than the guaranteed voltage to the running line, to thereby detect a leakage current value.

Abstract: An apparatus embodiment comprises a voltage source, a measuring device, a controller, and at least two connecting elements. The connecting elements connect to an electrical supply network comprising at least a phase conductor and a neutral conductor. The voltage source applies at least a first voltage and a second voltage to a pair of the conductors of the electrical supply network. The measuring device measures the resistance between the pair of conductors. The controller compares a first resistance measured by the measuring device between the pair of conductors to a predetermined first threshold resistance value and detects that an electric device is connected to the electrical supply network when the first resistance is lower than or equal to the first threshold. When an electric device is not detected, the controller is further configured to perform a higher voltage insulation test of the electrical supply network.

Abstract: A system is provided to determine whether an insulating layer of an implanted lead is damaged.

Abstract: Apparatus and method for partial discharge detection of turn-to-turn insulation in motor has a surge generator for generating a surge voltage to the windings of the motor by applying a pulse voltage, and a partial discharge current detector for detecting partial discharge currents between the winding turns of the motor. The surge generator generates in and between the windings of the motor the surge voltage that has the rise time and fall time corresponding to the rise time of the surge voltage observed at the motor terminal when the motor is driven by an inverter, and that is repeated at a frequency of 50 Hz to 20 kHz.

Abstract: A system and method for detecting and locating an insulation flaw in a solar generator on a spacecraft. The solar generator comprises a plurality of flaps. Each flap bears at least one solar cell that is connected to an electrical distribution network and electrically insulated from the flap. Each flap is connected, by a first load and by a second load, to a first electrical line and a second electrical line, respectively. The ratio of the impedances of the first load and of the second load of a flap being denoted as an impedance ratio of the flap. The solar generator comprises at least two flaps exhibiting different respective impedance ratios. The system comprises a component for evaluating the currents flowing in the first and second electrical lines, and a detector for detecting and locating an insulation flaw in the solar generator based on the evaluations of the currents.

Abstract: A device for determining partial discharge in an insulation system of a rotating electrical machine with low capacitance decoupling has a coupler as a high pass and an adapter device connected or connectable to the coupler. The adapter device has a frequency separating filter for dividing a decoupled signal provided by the coupler into a high frequency signal and a low frequency signal. A mixer is provided for the high frequency signal and the low frequency signal for converting the high frequency signal. An output is provided where the converted high frequency signal is tapped for evaluation by an evaluation device connectable to the adapter device.

Abstract: Provided is an electric vehicle including an electric system that generates drive power, a detector, and a controller. The electric system includes a power storage device, a drive device that uses power of the power storage device to generate drive power, a first relay provided between the positive electrode of the power storage device and the drive device, and a second relay provided between the negative electrode of the power storage device and the drive device. The detector is electrically connected to the power storage device and detects an insulation abnormality in the electric system. The controller determines the insulation state of the electric system on the basis of a detection result of the detector obtained when the first relay and the second relay are open and a detection result of the detector obtained when either of the first relay and the second relay is thereafter closed.

Abstract: Provided is an insulation resistance measuring circuit including: a source resistor unit including a first source resistor connected between a positive terminal of a battery and a second source resistor and the second source resistor connected between a negative terminal of the battery and the first source resistor; a voltage sensing unit sensing a voltage of the first source resistor as a first voltage and sensing a voltage of the second source resistor as a second voltage; and an insulation resistance measuring unit measuring an insulation resistance of the battery through a value obtained by dividing a difference between the first and second voltages by a sum between the first and second voltages.

Abstract: Methods for measuring insulation resistance in a photovoltaic (PV) array may include partitioning the PV array into groups of PV panels, isolating a group of PV panels selected for an insulation resistance measurement from other groups of panels by setting bypass selectors on each PV panel in the PV array, and making an insulation resistance measurement for the selected group. If a measured value of insulation resistance for a selected group corresponds to an insulation problem in a PV array component, a separate measurement of insulation resistance may be made for each PV panel in the selected group. Insulation resistance measurements may be made accurately and rapidly for large PV arrays without disconnecting and reconnecting cables between panels. Measurements may be made at frequent, regular intervals to permit changes in insulation resistance to be detected before damage from dielectric breakdown occurs.

Abstract: A malfunction detecting device for a solar cell panel includes an AC source that is provided on one of positive and negative sides of a solar cell panel body and can apply AC voltage superimposed on DC voltage to the solar cell panel, a measuring means provided on another of the positive and negative sides of the solar cell panel body to measure voltage or current output from the solar cell panel, and a control unit including a malfunction determination portion that controls the AC source to control input voltage or input current to be input to the solar cell panel and determines malfunction in the solar cell panel by comparing the input voltage or the input current to output voltage or output current measured by the measuring means. The malfunction determination portion includes a panel body malfunction determination portion and a bypass diode malfunction determination portion.

Abstract: The present invention relates to a method for determining partial discharges at an electrical component (10). In the case of the method, an electrical signal that comprises partial discharge pulses due to the partial discharges at the electrical component (10) is detected. Through filtering of the electrical signal by means of n filters (18-20) having n differing filter characteristics, n filtered partial discharge signals are generated. Respectively one of the filtered partial discharge signals is assigned, respectively, to one of the n filters (18-20), n being greater than or equal to two. Finally, the partial discharges are determined by linking the n filtered partial discharge signals.

Abstract: An insulation measurement apparatus includes a path including a first resistor, a capacitor electrically floated from a ground, and a second resistor between a positive to a negative electrode side of a power supply, a first switching element between the power supply positive electrode side and the capacitor, a second switching element between the capacitor and the power supply negative electrode side, a detection section detecting a charge voltage on the capacitor and determining a power supply insulation state, and a voltage setting section executing a power supply voltage measurement mode controlling the first and second switching elements to charge the capacitor for a predetermined time period, and an insulation voltage measurement mode charging a terminal of a positive or negative electrode side of the capacitor via a resistor between the power supply positive or negative electrode and the ground for a predetermined time period.

Abstract: Disclosed is an isolation resistance measuring apparatus having a fault self-diagnosing function and a fault self-diagnosing method using the same. The isolation resistance measuring apparatus having a fault self-diagnosing function detects whether a fault arises at the isolation resistance measuring apparatus by using first and second isolation detection voltages detected in a state where a diagnosing unit is not connected (an isolation resistance measuring mode) and first and second diagnosis detection voltages detected in a state where the diagnosing unit is connected (a fault self-diagnosing mode). By doing so, it is possible to self-diagnose a fault by using an original function of the isolation resistance measuring apparatus which may measure an isolation resistance.

Abstract: A method and device for monitoring partial discharges in high voltage electrical or power systems is provided. A low trigger level and a high trigger level electrical pulse amplitude levels are defined. At least one phase of the electrical system is monitored for an occurrence of a pulse within a defined minor time frame. A peak amplitude of a pulse occurring in the electrical system within the minor time frame is detected. It is determined if the detected peak amplitude of the pulse exceeds the lower and higher trigger levels. A pulse number is assigned to the pulse if the peak amplitude of the pulse exceeds the trigger levels. The pulse is captured if the pulse number associated with the pulse is less than a predetermined pulse number threshold in the minor time frame. The captured pulses are stored in a memory.

Abstract: A solar photovoltaic junction box for being electrically connected to a solar cell array. The junction box comprises a plurality of input branch lines electrically connected to solar cell strings, an output aggregate line that converges the plurality of branch lines, a back-flow preventing diode provided on each of the branch lines, a capacitor parallel-connected to each of the back-flow preventing diodes, an AC voltage generator that is provided on the aggregate line to allow an AC voltage to be applied to the solar cell array, a measuring means for measuring an alternating current flowing in the solar cell array, and a control unit comprising an malfunction determination portion for determining a malfunction in the solar cell array on the basis of the AC voltage applied by the AC voltage generator and the alternating current measured by the measuring means.

Abstract: A capacitor component is adapted for capacitive coupling to an electrical power apparatus in which a PD is suspected, such as a shielded power cable; and an impedance transformance device has an input side connected directly to the capacitor component. Together the two components are used as a sensor to pick up and convey PD signals to a PD signal-analyzing system. Although the two components inherently form a classic high-pass RC filter, in accordance with the invention the input impedance at the capacitor side is much greater than the output impedance at the signal-analyzing system side. The effect is to pass much more of the lower frequency components of the PD signal for analysis by the PD signal-analyzing system than if the tranformance device were not included.

Abstract: A method for monitoring and measuring an insulation resistance in ungrounded and grounded power supply systems includes the method steps of generating a periodic measuring signal, coupling in the measuring signal between active conductors of the power supply system to be monitored and ground, and detecting and evaluating measured values of the measuring signal. In one embodiment of the invention, the generated measuring signal is formed as a multi-frequency signal by the superposition of a finite number of harmonic oscillations with at least three harmonics. Alternatively, the multi-frequency signal can also be realized by means of a targeted, portioned construction of the signal shape in the time domain on the basis of a binary sequence optimization or by generating the measuring signal by means of the time-division multiplexing method.

Abstract: An electrical power supply device includes a DC voltage source with terminals, a controller, and an insulation-defect detecting device for detecting an insulation defect of the voltage source. The device has input terminals connected to source terminals, and circuits connected between respective input terminals and an intermediate point. The insulation-defect current-detection circuit connects between ground and the intermediate point. Both circuits have current-limiter circuits that open and close a connection between respective inputs and the intermediate point. Both current-limiter circuits are rated for traversal by a current of less than a standardized safety threshold when the first current-limiter circuit is closed and one of the terminals of the DC voltage source is shorted to ground. The control circuit is configured to simultaneously keep one current-limiter circuits open and the other closed.

Abstract: Methods and structures for leakage screening are disclosed. A method includes sorting devices manufactured from the same device design into voltage bins corresponding to a respective supply voltage. The method further includes determining a respective total power of each of the voltage bins. The method further includes determining a respective uplift power of the voltage bins. The method further includes determining a respective first leakage screen value for each of the voltage bins based on the respective uplift power of each of the voltage bins.

Abstract: A method for testing a mask article includes the steps of electrically connecting the mask article to an electrical sensor, applying a bias voltage to a plurality of testing sites of the mask article with a conductor, measuring at least one current distribution of the testing sites with the electrical sensor, and determining the quality of the mask article by taking the at least one current distribution into consideration.

Abstract: Embodiments of the present disclosure include a method of operating an arc fault detection system, an arc fault detection system, and a system. An embodiment is a method of operating an arc fault detection system coupled to a power line, the method including determining one or more arc fault detection windows in power line signals on the power line, the power line signals comprising a communication signal and an alternating current (AC) power signal. The method further includes receiving the power line signals from the power line during the one or more arc fault detection windows, and performing arc fault detection processing on the received power line signals.

Abstract: A force compensated probe for electrical measurement is provided and includes a support structure having a back plate and sidewalls, a probe for electrical measurement of an article and an elastic base disposed to supportively couple the probe to the back plate such that the probe normally protrudes away from the back plate beyond distal edges of the sidewalls, and, when the probe is applied to the article for the electrical measurement such that components of the support structure contact the article, a predefined load is consistently applied to the elastic base.

Abstract: When, in a state where an AC ground fault occurred on the secondary side of a three-phase inverter circuit, a flying capacitor reaches a continuous charging state while forming a charge circuit including a ground fault resistance due to an AC ground fault, the ground fault resistance due to an AC ground fault is obtained using the same method as that for a positive-side ground fault resistance or a negative-side ground fault resistance due to a DC ground fault. Even if, in the state where the flying capacitor reaches the continuous charging state, a switching duty ratio of respective semiconductor switches of the three-phase inverter circuit varies, a value of a ground fault resistance due to an AC ground fault can be accurately obtained without using the data of the switching duty ratio of respective semiconductor switches of the three-phase inverter circuit.

Abstract: The present invention relates to a ferroelectric analyzing device and a method for adjusting ferroelectric domain switching speed with the ferroelectric analyzing device, and pertains to the technical field of characteristic test of solid-state dielectrics. The ferroelectric analyzing device comprises a voltage pulse generator for generating square pulse signal, which is biased on a ferroelectric thin film so as to switch the polarization of ferroelectric domains, the ferroelectric analyzing device further comprises a variable resistor which is connected in series with the ferroelectric thin film. The variable resistor is used for adjusting domain switching current so as to realize adjustment of domain switching speed of ferroelectric domains. In the method, the square pulse signal is biased on the ferroelectric thin film, and an adjustment of domain switching speed of ferroelectric domains can be realized by adjusting the resistance value of the variable resistor.

Abstract: An apparatus for detecting deterioration of a lightning arrester includes: a high-frequency power supply; a pair of detecting terminals 12 connected to the high-frequency power supply via a resistance for measurement and touched to the terminals of the arrester; a voltage detecting circuit for obtaining a terminal voltage of the resistance for measurement when the detecting terminals touch the terminals of the arrester; and a determining circuit for comparing the detected voltage with a reference value to determine whether the detected voltage is good or bad. A voltage having a frequency sufficiently higher than the operation frequency of a power line is generated by the high-frequency power supply and applied to the arrester, and change in electrical characteristics due to deterioration of zinc oxide elements is detected as change in current including capacitive current, and then it is determined whether the detected change is good or bad.

Abstract: A diagnostic/prognostics system for failure detection in an electrical insulation system is provided. The system includes at least two current transformers designed to detect high frequency component signals from the insulation system. The system also includes a data acquisition module coupled to the at least two current transformers, wherein the data acquisition module receives the high frequency component signals and analyzes the received high frequency component signals to identify one or more faulty components in the electrical insulation system.

Abstract: Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises an oscillator part which generates a high voltage that has a high frequency and is modulated with a lower frequency at an output, and a demodulator which is connected to the oscillator part, demodulates the high voltage, and recovers the low frequency therefrom. A discharge resistor for the capacitive load is connected in parallel to the demodulator, said discharge resistor conducting back to the aforementioned output.

Abstract: An electrical insulation test as well as the production of photovoltaic modules, especially of thin-film photovoltaic modules, provides a current-conducting component disposed on a panel-shaped substrate, which are insulated electrically in the area of the module edge. In order to simplify testing of the insulation of such photovoltaic modules, it is proposed that, during the production of the photovoltaic module, testing of the electrical insulation takes place, for which, through the use of a mechanical contacting device a test voltage is applied between the module edge on the one hand and the electrical connections of the photovoltaic module, which are remote from the module edge, lead to the outside, on the other hand.

Abstract: Method for the simulation of defects in the case of spark testers, in which breakdowns are recognized and displayed by a detector and added by means of a defect counter, wherein the high voltage is applied to a stationary standard spark gap and pulsed test voltages of predetermined level, duration and frequency are generated by the high voltage generator of the spark tester in short regular intervals.

Abstract: A back end of the line (BEOL) fuse structure having a stack of vias. The stacking of vias leads to high aspect ratios making liner and seed coverage inside the vias poorer. The weakness of the liner and seed layers leads to a higher probability of electromigration (EM) failure. The fuse structure addresses failures due to poor liner and seed coverage. Design features permit determining where failures occur, determining the extent of the damaged region after fuse programming and preventing further propagation of the damaged dielectric region.

Abstract: A method is disclosed for monitoring galvanic isolation of a fuel cell device. At least one stack of fuel cells and at least one load circuit for fuel cells are arranged to an electrically freely floating configuration towards at least one structure near fuel cells. A controlled switching is performed via at least two switching points to at least one measurement element having known impedance in connection to the at least one structure. Measurements are performed from the measurement element to form voltage information. The voltage information and at least voltage information between switching points are processed to check floatages of fuel cells in relation to said at least one structure.

Abstract: An electric operating system for a construction machine includes a first insulation resistance degradation detection device including a first voltage waveform generation device and a first detection section. The first detection section is connected to an electrical storage device and to the first voltage waveform generation device with respect to a relay and is adapted to detect degradation in the insulation resistance of the electrical storage device by measuring waveform changes input from the first voltage waveform generation device. A second insulation resistance degradation detection device includes a second voltage waveform generation device and a second detection section connected to a drive system and to the second voltage waveform generation device with respect to the relay, and is adapted to detect degradation in the insulation resistance of the drive system by measuring waveform changes input from the second voltage waveform generation device.

Abstract: To detect accurately an insulation fault in a load circuit, Power supply lines and an electric heater (a load circuit) are connected by a detecting portion to detect a detected voltage (detected value) in accordance with the magnitude of a leakage current Id that flows through a ground between the power supply lines and the electric heater, and an evaluation as to whether or not there is a breakdown of insulation of the electric heater relative to the ground is performed by an evaluating portion based on the detected value obtained when the relay contact points are open.

Abstract: A bus terminal is isolated from ground potential during normal operation of the vehicle. A first current is applied to the bus terminal. A current level detector is arranged to detect a first level of the first current, or a corresponding observed voltage level, that exists or flows from the bus terminal to ground. A compensator is configured to compensate for a range in the detected first level by applying a corresponding compensating voltage level to a first resistor coupled to the current level detector. An electronic data processor is capable of estimating a first isolation level between the bus terminal and ground based on the detected first level.

Abstract: A method and to a device for insulation monitoring in ungrounded electrical direct or alternating current networks includes coupling in a measuring signal between active conductors of the network to be monitored and ground and registration of measured values of the measuring signal. The registered measured value of the measuring signal is determined in the form of a signal quality value which is displayed on a display.

Abstract: A method for testing a mask article includes steps of electrically connecting the mask article to an electrical sensor, applying a bias voltage to a plurality of testing sites of the mask article with a conductor, measuring at least one current distribution of the testing sites with the electrical sensor, and determining the quality of the mask article by taking the at least one current distribution into consideration.

Abstract: An active matrix electrowetting on dielectric (AM-EWOD) device includes a plurality of array elements configured to manipulate one or more droplets of fluid on an array, each of the array elements including a corresponding array element circuit. Each array element circuit includes a top substrate electrode and a drive electrode between which the one or more droplets may be positioned, with an insulator layer being interposed between the one or more droplets and the drive electrode; and write circuitry configured to write data to the array element. At least some of the array element circuits include measure circuitry configured to detect a pinhole defect in the insulator layer.

Abstract: A first X capacitor is connected between one of a plurality of hot line sections of a hot line that is located at an output side of a first relay as viewed from a commercial alternating-current power supply, and one of a plurality of neutral line sections of a neutral line that is located at an input side of a second relay as viewed from the commercial alternating-current power supply. A second X capacitor is connected between one of the hot line sections that is located at the output side of the first relay as viewed from the commercial alternating-current power supply, and one of the neutral line sections that is located at an output side of the second relay as viewed from the commercial alternating-current power supply.

Abstract: Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises two oscillators, the frequencies of which differ from one another by twice said low frequency, a resonance circuit which is fed in an interfering manner by the oscillators, is adjusted to the oscillator frequencies and causes a voltage rise of the interfering oscillator frequencies, and a demodulator for disconnecting the low-frequency high voltage generated by the interference from the resonance circuit and applying the same to the load.

Abstract: The present invention relates to a partial discharge sensor for a high-voltage insulation monitoring device comprising a housing and located in the housing a measurement circuit for measurement of partial discharges in a high voltage system to be tested and a coupling capacitor having one electrode connected to the measurement circuit and the other electrode to a first high voltage conductor to be connected to a high voltage line of the system to be tested, wherein it further comprises a calibration circuit located in the housing and comprising a calibration capacitor having one electrode connected to the calibration circuit and the other electrode connected to said first or a second high voltage conductor to be connected to a high voltage line.

Abstract: A method for testing a mask article includes the steps of electrically connecting the mask article to an electrical sensor, applying a bias voltage to a plurality of testing sites of the mask article with a conductor, measuring at least one current distribution of the testing sites with the electrical sensor, and determining the quality of the mask article by taking the at least one current distribution into consideration.

Abstract: An insulation resistance detecting apparatus is provided to detect an insulation resistance of a load circuit. The insulation resistance detecting apparatus includes a coupling capacitor of which a first end is connected to the load circuit; a periodic waveform output section which is connected to a second end of the coupling capacitor, and outputs a periodic waveform to the second end; a waveform shaping section which extracts and amplifies a part of the periodic waveform including a peak point; and an arithmetic operation section which determines the insulation resistance of the load circuit on the basis of a first wave height as a wave height value of a waveform outputted from the waveform shaping section and a second wave height value as a wave height value of the periodic waveform.

Abstract: The present invention relates to a device operable electrically via a mains voltage connection, in particular without a ground wire connection, having a live element and having an application part, wherein the application part is insulated by a basic insulation with respect to the live element. In this respect, an insulation monitor is provided which monitors the quality of the basic insulation of the application part with respect to the live element. The present invention furthermore comprises a medical device having a heating module for heating a medical fluid, wherein the heating module comprises a heating element having a heating coil arranged on a first ceramic layer, wherein the heating element is arranged on a second ceramic layer, wherein the second ceramic layer advantageously forms a heating plate of the heating module.

Abstract: A method for determining an insulation resistance of an electric DC circuit having at least a first and a second terminal includes performing a measurement cycle, verifying whether the change of a measured current exceeds a predetermined change rate, calculating a total insulation resistance, and calculating a first insulation resistance between the first terminal and a reference potential and a second insulation resistance between the second terminal and the reference potential. An insulation resistance measurement circuit is also provided for carrying out the aforementioned method.

Abstract: A sensor for condition monitoring the high voltage insulation of an electrical, generation, transmission or distribution system and/or an item of plant is described. The sensor comprises an impedance measurement unit that connects directly, via a single point of connection, to the electrical system to be tested. The electrical components of the impedance measurement unit are arranged so that high frequency partial discharge signals and low frequency power cycle information signal are preferentially transmitted through separate branches. Analysis of these separated signals thus enables extraction of information about the insulation of the electrical system being monitored. Safe operation of the sensor for users is also achieved through an opto-electronic circuit being employed to control the impedance measuring unit.

Abstract: A system for the measurement of degradation of electrical wire insulation quality is described. The system includes a clamping device for engaging the electrical wire to be tested for insulation degradation, the clamping device comprising a channel formed therein for placement of the electrical wire, a plurality of plates placed proximate the channel, the plates electrically connected to generate a capacitance and placed proximate the channel such that the wire insulation provides a portion of a dielectric for the generated capacitance, and a measurement device operatively attached to the plurality of plates such that the measurement device is configured to indicate an amount of degradation associated with the wire insulation based on at least one of the measured capacitance and dissipation factor.

Abstract: An apparatus and method for identifying the presence of high conductivity or permittivity conditions in a wide range of electrically insulating materials is disclosed. The apparatus includes a grounded enclosure containing electronics for controlling measurement and communication processes and first and second spaced-apart electrode assemblies for engaging an insulator to be tested. The first and second electrode assemblies are mounted in the enclosure for linear movement such that pressing of the first and second electrodes against an insulator causes the electronics to initiate a measurement.

Abstract: The disclosure relates to minimizing the potential damage caused by the failure of a single central Intelligent Electronic Device (IED) responsible for calculating, assigning and storing information about switchyard zones of a high or medium voltage switchyard comprising switchyard elements interconnected by lines, and wherein the switchyard is operated by means of a Substation Automation system including a plurality of Intelligent Electronic Devices. For example, a distributed switchyard zone management is disclosed, comprising a distributed storage of the knowledge about the switchyard zones. Assignments of individual switchyard elements or components, such as switches and connectivity nodes, to the various switchyard zones are stored on several IEDs. If one of these IEDs fails, the services or applications based on switchyard zones thus are not necessarily doomed, as would be the case if the entire knowledge about switchyard zones were stored on one single central IED.

Abstract: An insulation measuring apparatus having a measuring circuit including a first capacitor; a control unit that reads a voltage set on the first capacitor to decide an insulation state of a power supply, and control a path configuration of the measuring circuit; a switching section provided in a path located between the measuring circuit and the control unit; and a second capacitor provided between a ground and a path located between the switching section and the control unit. The control unit controls the path configuration of the measuring circuit, by turning ON the switching section to set a voltage corresponding to the voltage that is set on the first capacitor on the second capacitor, and then by turning OFF the switching section to read the voltage set on the second capacitor and to discharge an electric charge corresponding to the voltage being set on the first capacitor.

Abstract: A discharge amount measuring device includes a power source, first and second sensors, a calibration wire, and a measuring portion. The power source applies a voltage to a coil of a rotational electric machine. The first sensor detects a current flowing through the coil. The calibration wire has an end connected to the coil. The second sensor detects a current flowing through the calibration wire. The measuring portion forms a calibration line based on a first waveform detected by the first sensor and a second waveform detected by the second sensor. The measuring portion calculates a discharge amount based on the calibration line.