Abstract: A device for a hydraulic actuating system, e.g., a motor vehicle brake, a clutch or a gear selector, may include the following components arranged in one housing, forming a main module: at least one pressure supply device driven by an electric motor drive, and a valve arrangement comprising at least one solenoid valve. The device may further include an electrical control unit (ECU) and valve output stages and sensors. The main module may be electrically and/or hydraulically connected to at least one further system component, which system component may include and actuating device and a travel simulator.

Abstract: A detection sensor including an alternating current (AC) permanent magnet synchronous motor (PMSM) housed in a casing, a motherboard and an AC servo controller with a permanent memory in electronic communication with the PMSM, and a shaft extending from the PMSM configured to rotate a sensing needle wherein the sensing needle is configured to sense an object in its rotation.

Abstract: A motor controller executing a current regulator and a modulation routine in separate update intervals provides an improved fundamental voltage waveform for a motor controlled by the motor controller. The current regulator is executed at a first periodic update rate and the modulation routine is executed at a second periodic update rate, where the frequency at which the modulation routine executes is at least twice the frequency at which the current regulator executes. Executing the current regulator and the modulation routines at different frequencies results in the current regulator generating a single voltage reference signal for multiple periods of the modulation routine. To reduce voltage ripple induced by decoupling execution of the current regulator and the modulation routine, the motor controller extrapolates the voltage reference generated by the current regulator into multiple voltage reference signals, where a unique voltage reference signal is provided for each period of the modulation routine.

Abstract: An integrated circuit includes a power-on reset (POR) circuit and a digital logic circuit. The POR has first and second control outputs. The POR circuit is configured to generate a first control signal on the first control output responsive to a supply voltage on the supply voltage node exceeding a first threshold voltage and is configured to generate a second control signal on the second control output responsive to the supply voltage exceeding a second threshold voltage. The digital logic circuit has a first control input coupled to the first control output of the POR circuit and has a second control input coupled to the second control output of the POR circuit. The digital logic circuit is configured to initiate a first read transaction responsive to assertion of the first control signal and to initiate a second read transaction responsive to assertion of the second control signal.

Abstract: The present disclosure relates to an initial charging system for a medium-voltage inverter and a method for controlling the system. The initial charging system comprises: a first switch for switching between a medium-voltage inverter and a power supply thereto; a second switch for switching between an output stage of the medium-voltage inverter and an electric motor; a first initial charging unit disposed between and connected to the first switch and the medium-voltage inverter for limiting an initial excitation current to be applied to the phase-shift transformer; and a second initial charging unit disposed between and connected to an input stage of each power cell and the direct current (DC) link capacitor for limiting an initial charging current in the direct current (DC) link capacitor.

Abstract: The present invention relates to a vehicle access system (1) having a tracking means (11; 23, 25, 27) for tracking a positional movement pattern of a user (D) relative to a vehicle (3). A controller (9) is provided for controlling the opening and/or closing of a vehicle opening (5). The controller (9) communicates with a storage device (15) and the tracking means (11; 23, 25, 27). The controller (9) has a comparator (17) for comparing the positional movement pattern with one or more pre-defined movement maps stored in the storage device (15). The controller is configured to open the vehicle opening when the comparator (17) determines that the positional movement pattern corresponds to a first of the pre-defined movement maps. Alternatively, or in addition the controller can be configured to close the vehicle opening when the comparator (17) determines that the positional movement pattern corresponds to a second of said pre-defined movement maps.

Abstract: A vehicle includes an electronic control unit. The electronic control unit is configured to perform control of an inverter by switching a plurality of controls including i) first PWM control of generating a first PWM signal of a plurality of switching elements by comparison of voltage commands of respective phases based on a torque command of a motor with a carrier voltage and switching the plurality of switching elements, and ii) second PWM control of generating a second PWM signal of the plurality of switching elements based on a modulation factor of a voltage and a voltage phase based on the torque command and the number of pulses in a predetermined period of an electrical angle of the motor and switching the plurality of switching elements. The electronic control unit is configured to limit execution of the second PWM control when an abnormality occurs in the rotational position sensor.

Abstract: According to an embodiment, a method for compensating instantaneous power failure includes determining whether an input voltage of a plurality of power cells is less than or equal to a first threshold voltage, decreasing, when the input voltage is less than or equal to the first threshold voltage, an output frequency of the inverter, determining whether a voltage of a direct current (DC) link is greater than or equal to a second threshold voltage, and increasing, when the voltage of the DC link is greater than or equal to the second threshold voltage, the output frequency of the inverter. Overvoltage trip may be prevented at the power restoration time and overcurrent trip caused by increase in the slip frequency may be prevented. Thereby, reliability of a medium inverter may be enhanced, and a continuous operation time increased compared to the conventional cases may be ensured.

Abstract: A control and supply unit for an actuating device of a choke, a valve, a blow-out preventer or some other device applied in the field of oil and natural gas production. The control and supply unit includes a vibration detection means to detect vibrations caused by a conveyed flow. The conveyed flow can be controlled by the actuating device.

Abstract: Provided is a current measuring relay device capable of measuring a current flowing in a relay and controlling an operation of the relay based on the measured result, without depending on a control operation of an external control device such as a battery management system (BMS) by integrating the relay with a current measuring sensor.

Abstract: A drive device of a window positioning device positions a window of a vehicle to selectively cover a window opening. The drive device is operated by a control device. When the window is fully closed, the drive device is operated (a) in an opening direction and then (b) in a closing direction. The operation of the drive device is carried out depending on a drive parameter. In a), using a first value of the drive parameter, the drive device is brought into a first reduced load position, and in b), using a second value of the drive parameter, the drive device is brought into a second reduced load position in which the window positioning device is in a reduced load state. A control device and a window positioning device are used.

Abstract: A vehicle window opening and closing control device has a driver seat unit that is provided in a driver seat of a vehicle, and a sub-switch that is provided in a seat other than the driver seat. The driver seat unit includes a main switch that operates opening and closing of a first window of the driver seat and a second window of the seat other than the driver seat and a controller that controls a driver seat motor provided in the driver seat and an other-seat motor provided in the seat other than the driver seat to perform manual opening and closing and automatic opening and closing of the first and second windows based on the operation of the main switch. The sub-switch is a switch that performs only the manual opening and closing of the second window using the other-seat motor.

Abstract: A hybrid wheel loader is provided, the hybrid wheel loader achieving high work efficiency even with a short supply of power to be output relative to a vehicle power requirement. The hybrid wheel loader includes a motor generator 6 connected to an engine (1), a hydraulic pump (4) connected to the motor generator, a hydraulic actuator (51, 52, 53) driven by hydraulic oil supplied from the hydraulic pump, a travel electric motor (9) for driving wheels (61), and an electrical storage device (11) connected to each of the motor generator and the electrical storage device via respective inverters (7, 10). When a total requirement power value is greater than a hybrid output upper limit value, either one of a hydraulic requirement power value Pf and a travel requirement power value Prun is limited according to an operation of the wheel loader to thereby set the total requirement power value to a value equal to, or less than, the hybrid output upper limit value.

Abstract: A PI calculation unit of a rectangular-wave voltage control unit calculates a control deviation by performing a PI calculation on a torque deviation relative to a torque command value, and outputs a voltage phase of a rectangular-wave voltage in accordance with the control deviation. A rate-of-change limiter imposes a restriction on the rate of change of the voltage phase. Here, the rate-of-change limiter lessens the restriction on the rate of change of the voltage phase, when the rate of change of the rotational speed of an electric motor is larger than a predetermined value representing an abrupt change of the rotational speed of the electric motor.

Abstract: A system for controlling a disconnect switch via a network may include a disconnect switch and a drive. The disconnect switch may receive alternating current (AC) power from an AC power supply, and the drive may then receive the AC power via the disconnect switch. The drive may include a processor that may communicatively couple to the disconnect switch. As such, the processor may control a drive operation that corresponds to the drive and control a disconnect operation that corresponds to the disconnect switch.

Abstract: A technique for controlling drive currents to respective windings of a multi-winding brushless motor comprises monitoring an output of the motor and a demand of the motor, determining whether a failure mode has occurred, the failure mode being an instantaneous complete or partial failure to generate demanded output; and, upon detection of a failure mode on a first winding, distributing a demand contribution that is not being produced by the first winding to one or more of the windings that are not in a failure mode. The demand may be torque demand, and the failure modes may include winding failure, and voltage and/or current saturation. Improved torque output is generated by the redistribution of demand among phases in the event of a failure mode.

Abstract: The motor monitoring system of the present disclosure uses several calculated monitoring values to determine a status of a motor and take a predetermined action when a threshold corresponding with the monitoring value is exceeded. The threshold may be calculated by an intelligent electronic device (IED) monitoring the motor. The predetermined action may include further monitoring of the motor. The predetermined action may include monitoring equipment not directly monitored by the IED.

Abstract: An electric actuator has a switch, a setting unit and a resetting unit. The switch is provided in a supply path of electric power from an electricity storing body to a motor. The switch opens and closes the supply path. The setting unit is operated through receiving a supply of electric power from the electricity storing body in response to an instruction from an operator. The setting unit opens the switch provided in the supply path for electric power from the electricity storing body to the motor. The resetting unit is operated through receiving a supply of electric power from an external power supply when the external power supply has been restored from being cut off. The resetting unit closes the switching unit provided in the supply path of electric power from the electricity storing body to the motor.

Abstract: A motor control circuit calculates an ?-axis current i? and a ?-axis current i? in a fixed coordinate system based on a W-phase (sensor phase) of an AC motor. The control circuit calculates, at each switching time point and each intermediate time point, the ?-axis current i? from a current iw.sns sensed in the W-phase, and the ?-axis current i? from a differentiated value ?i? determined from the variation quantity of the ?-axis current between every two successive switching time points or intermediate time points. Subsequently, the control circuit calculates a current phase x?=tan?1(i?/i?) relative to the W-phase. Subsequently, the control circuit calculates an estimation factor according to the current phase x? and determines an estimated current iu.est in the U-phase of the AC motor by multiplying the sensed current iw.sns by the calculated estimation factor.

Abstract: A point value corresponding to a load state of an electric motor is set. The load state of the electric motor is detected so as to calculate a load point value of the electric motor and accumulate the load point values (S3, S4). A wiper-device operation mode is identified (S6). A difference Ptd between the accumulated load point value for forward operations and the accumulated load point value for return operations is compared with a criterion threshold value SVb (S24). When the difference Ptd exceeds the criterion threshold value SVb, it is determined that a vehicle is in a high-speed running state. Then, an angle of rotation of the electric motor is reduced to narrow a wiping angle of the wiper blade (S25). In this manner, an upper reversal position is set closer to a return side than a given position. As a result, overrun caused by the deflection of a blade or the like due to a wind generated by running when the vehicle is running at a high speed is prevented.

Abstract: A voltage converter includes a first circuit and a second circuit. The first circuit includes two or more reactors and at least one switching element. One terminal of each of the reactors is connected in parallel with respect to a power source. The at least one switching element is connected to the other terminal of each of the reactors. The second circuit includes at least one rectifier of which one terminal is connected to the electrical load. The second circuit shares with the first circuit the at least one switching element connected to the at least one rectifier. The first circuit is connected such that the power source charges the respective reactors when the at least one switching element is turned ON. The second circuit is connected such that the reactors discharge power to the electrical load when the at least one switching element is turned OFF.

Abstract: An ECU that controls a motor includes: a target current value setting unit setting a target current; a voltage detecting unit detecting a detected voltage on the basis of a detection signal from a voltage sensor; a voltage calculation unit calculating an estimated voltage on the basis of a power supply voltage of a battery; and an induced voltage observer calculating an induced voltage generated at the motor using an inter-terminal voltage based on the estimated voltage when the target current is set to a value other than zero; whereas the induced voltage observer calculates the induced voltage using an inter-terminal voltage based on the detected voltage when the target current is set to zero.

Abstract: The fan control circuit includes a first switch unit, a second switch unit, and a delay unit. The first switch unit outputs a first or a second voltage according to a power good signal. The delay switch unit performs a delay operation on the power good signal, and outputs different control signals to the second switch unit before or after the delay operation exceeds a predetermined time. The second switch unit receives the control signals from the delay unit, and connects or disconnects the first switch unit to or from a fan according to the control signals.

Abstract: To detect an entrapment situation when a driven component is adjusted using a mechanical adjustment system which has an electric motor (2), a value (Fakt) relating to the force acting upon the driven component is compared with a threshold value (FTh) relating to a reference value (FRef). The reference value (FRef), and thus the threshold value (FTh), are continuously matched, for the purpose of force tracking, with the force value which changes during the movement of adjustment depending on the mechanical system.

Abstract: Presented is a roller shade system that includes a flexible shade material having a lower end, a rotatably supported roller tube that windingly receives the shade material, a stepper motor that operably engages the roller tube to rotate the roller tube to move the lower end of the shade material between a first position and a second position, an optical sensor configured for capturing an image frame of the shade material at linear positions along the shade material as the lower end of the flexible shade material moves from the first position to the second position, and a stepper motor controller configured for controlling the frequency of input pulses to the stepper motor to move the lower end of the flexible shade material from the first position to the second position at a substantially constant linear velocity in response to position information obtained from the plurality of captured image frames.

Abstract: A technique for controlling drive currents to respective windings of a multi-winding brushless motor comprises monitoring an output of the motor and a demand of the motor, determining whether a failure mode has occurred, the failure mode being an instantaneous complete or partial failure to generate demanded output; and, upon detection of a failure mode on a first winding, distributing a demand contribution that is not being produced by the first winding to one or more of the windings that are not in a failure mode. The demand may be torque demand, and the failure modes may include winding failure, and voltage and/or current saturation. Improved torque output is generated by the redistribution of demand among phases in the event of a failure mode.

Abstract: An electric power steering device includes: an electric power source for supplying first current; a controller for setting a current instruction value; multiple electric power converters for converting the first current to second current corresponding to the current instruction value; multiple pairs of windings for generating a driving force of a motor; and a failure detection element for detecting failure of the electric power converters and the windings. The controller reduces the current instruction value to be equal to or smaller than a predetermined instruction value of a normal operation when the failure detection element detects the failure. The controller controls the electric power converter in a normal state to supply the second current to a corresponding winding.

Abstract: An electric vehicle is proposed which can achieve early detection of abnormal short-circuit of motor coils, thus avoiding various driving problems. The electric vehicle includes a motor unit configured to drive a wheel. The motor unit includes a synchronous motor with three-phase motor coils. The three-phase motor coils include a first motor coil, a second motor coil and a third motor coil of different phases. One end of the first motor coil, one end of the second motor coil and one end of the third motor coil are connected with each other at a neutral point in a star connection. The electric vehicle also includes an abnormal short-circuit monitor configured to detect an abnormal short-circuit of the motor coils, and also includes an abnormalities-responsive disconnection unit configured to electrically disconnect the motor coils from the neutral point.

Abstract: There is provided a control system for an electric motor to which electric power is supplied from a DC power supply via a multi-phase inverter, the multi-phase inverter including switch units respectively provided on a positive side and a negative side of arms corresponding to respective phases, each switch unit including a switching element and a reflux diode connected in parallel thereto. The control system comprises a phase current detection unit for detecting phase currents which flow between the inverter and the electric motor, a DC component acquiring unit for acquiring DC components of the respective phase currents, and a short-circuiting determination unit for determining that a short-circuit failure occurs in the inverter when at least one of the DC components of the phase currents acquired by the DC component acquiring unit exceeds a threshold. Consequently, the short-circuit failure of the inverter can be detected even though the control of the electric motor is stopped.

Abstract: An electric turning device includes an electric motor configured to drive and turn an upper turning body that is rotatably arranged on a base part, an inverter that supplies electric power to the electric motor, a control part that supplies a drive command for controlling drive operations of the electric motor to the electric motor according to a lever input amount, and an abnormality detecting part that detects an abnormality. When the abnormality detecting part detects the abnormality, the control part arranges the drive command to include a vibration component and supplies the drive command including the vibration component to the electric motor.

Abstract: An error condition detection circuit coupled to the motor control circuit reports an error condition when actual motor operation deviates from predetermined desired motor operation. An overcurrent threshold comparator compares motor current with a threshold data value stored in a data storage register, and sets an overcurrent flag when the motor current exceeds the threshold. A current interrogation processor monitors the reported error condition and is programmed to respond to the error condition by iteratively reading the overcurrent flag and decrementing the overcurrent threshold data value by a predetermined decrement amount until the overcurrent flag becomes set. The current interrogation processor is further programmed to report the overcurrent threshold data value extant at the time the flag becomes set as an estimate of electric current.

Abstract: A magnetic drilling stand is disclosed having a drilling unit (20), having an electromagnet (14) for fixing the magnetic drilling stand (10) on a component (12), having a voltage source which can be coupled to the electromagnet (14), and having a controller (28) for monitoring the holding force of the electromagnet (14), with the controller (28) having a device for monitoring the current level of the electromagnet (14), in order to identify a fault state or an adequate magnetic holding force, with a signal for an adequate magnetic holding force being produced only if, within a test phase, the current level of the electromagnet is below a respectively predetermined threshold value at at least two predetermined times after the start of the test phase.

Abstract: A door closer with a self-powered control unit is disclosed. The control unit for the door closer includes a drive gear configured to rotate in response to movement of a door, and a chain arranged to cooperate with the drive gear to produce linear motion in response to rotation of the drive gear. At least one gear creates rotational motion from the linear motion of the chain to turn a generator and generate electricity to power the control unit. In some embodiments, a set of clutch gears is disposed between the chain and the gear creating the rotational motion from the chain so that only one direction of the rotational motion is transferred to the generator in response to movement of the door in any direction. The control unit can additionally include a power management circuit to store energy from the generator.

Abstract: Cordless power tools include a pistol housing having an upper portion that merges into a downwardly extending handle, a DC motor residing in the upper portion of the housing, the DC motor having a rotor that drives an output shaft; a torque transducer on board the tool in communication with the output shaft; and a dynamic motor control circuit residing in the housing in communication with the motor and torque transducer. The dynamic motor control circuit includes a Kelvin resistor in communication with the motor for measuring motor current and digital hall switches in communication with the motor for measuring motor speed. The motor current can vary by at least 100 A during operation.

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: Provided are a method for compensating instantaneous power failure in medium voltage inverter and a medium voltage inverter system by using the same, the method for compensating instantaneous power failure in medium voltage inverter including a plurality of power cells supplying a phase voltage to a motor by being connected to the motor in series, the method including decreasing an output frequency of the plurality of power cells by as much as a predetermined value at a relevant point where an input voltage of the plurality of power cells is less than a reference value, decreasing the output frequency at a predetermined deceleration gradient, and maintaining the output frequency during restoration of input voltage as long as a predetermined time, in a case the input voltage is restored.

Abstract: When a vehicle collision is detected, a electric connection between a power supply and an input stage of an inverter is switched to the disconnected condition. Then, when a rotation speed of an alternating current motor is higher than an allowable rotation speed or a terminal voltage of a storage unit provided at the input stage is higher than an allowable terminal voltage, an exciting current command value is set at a value other than zero and a torque current command value is set at zero, and when the rotation speed is equal to or lower than the allowable rotation speed and the terminal voltage is equal to or lower than the allowable terminal voltage, both command values are set at zero. An exciting current component and a torque current component of an alternating current supplied from the inverter to the motor are controlled according to the set command values.

Abstract: A system and method are provided for controlling the speed of a motor driving a load that is electrically connected to a generator driven by an engine, through use of a first control feedback loop configured to control the rotor flux of the motor by controlling the field excitation of the generator, and a second control feedback loop configured to control the speed of the motor by controlling the throttle position of the engine.

Abstract: The invention relates to a safety controller for an actuating drive (2.1, 2.2, 2.3) for controlling a gas flow or a liquid flow in an open-loop or closed-loop manner by means of a flap (3.1, 3.2, 3.3) or a valve, in particular in the field of heating, ventilation, and air conditioning (HVAC) systems, fire-protection systems, and/or room protection systems. A safety circuit (9.1, 9.2, 9.3) is implemented to ensure the energy supply in a safety operating mode if an electricity supply circuit (8.1, 8.2, 8.3) drops off or is lost. A control value output circuit (1.1, 1.2, 1.3) detects status signals, in particular signals of a sensor (11.1, 11.2, 11.3), and/or status parameters of a system and/or a specifiable setting of an adjustment device that can be actuated manually. The safety control value is set to one of at least two different control values (SW1, SW2, . . . ) depending on the status signals so that the safety position of the flap is determined adaptively.

Abstract: Provided is an apparatus and method for controlling medium voltage inverter, whereby a frequency outputted by the medium voltage inverter is fixed, in a case an instantaneous power interrupt occurs while the medium voltage inverter drives a motor, and a voltage level of an AC power generated by the medium voltage inverter is reduced and outputted in response to a predetermined deceleration slope to control the medium voltage inverter.

Abstract: Systems and methods for operating a solar direct pump are provided. A system for controlling an alternating current (AC) pump includes a photovoltaic module, a temperature sensor that measures a temperature of the photovoltaic module, a calculator that calculates a maximum power point (MPP) voltage of the photovoltaic module based on the temperature of the photovoltaic module, and a frequency controller that adjusts a reference frequency of power supplied to the pump based on the MPP voltage.

Abstract: Presented is a system for synchronizing movement of roller shades each from a first position to a common second position. The system includes a master controller, a plurality of optical assemblies each configured to obtain information related to the position of one of the roller shades, and a plurality of motor assemblies. Each of the motor assemblies is configured for receiving the position information from one of the plurality of optical assemblies, receiving a master shade movement time from the master controller, and moving one of the of roller shades from the first position to the common second position in response to the received position information so that the roller shade arrives at the common second position simultaneously with the other roller shades in a time equal to the master shade movement time.

Abstract: Presented is a method for synchronizing movement of a plurality of roller shades each disposed at a first position to a common second position. The method includes obtaining information related to the position of each of the plurality of roller shades with a respective one of a plurality of optical assemblies, and moving each of the plurality of roller shades from the first position to the common second position in response to the respective obtained position information so that each of the plurality of roller shades arrives at the common second position at the same time.

Abstract: The method for the automatic adjustment of a protective device includes determining an integral of the square of a motor current over time on the basis of a time motor current profile of an asynchronous motor on a load, after switching on and reversing and deriving a tripping time of the overcurrent release on the basis of the determined integral, the integral, which corresponds to a heating of the asynchronous motor, being related to a multiple of the square of the rated current, and the motor current profile including at least the starting current, the transient and the selected motor rated current.

Abstract: The power circuit comprises a voltage conversion part converting an input voltage entered in accordance with a voltage of a power source to generate an output voltage and outputting the generated output voltage to the motor and a current detection part outputting a first signal in accordance with a current flowing through a given part of the power circuit. The voltage conversion part lowers the voltage value of new output voltage being generated when the current detection part outputs the first signal.

Abstract: To detect an entrapment situation when a driven component is adjusted using a mechanical adjustment system which has an electric motor (2), a value (Fakt) relating to the force acting upon the driven component is compared with a threshold value (FTh) relating to a reference value (FRef). The reference value (FRef), and thus the threshold value (FTh), are continuously matched, for the purpose of force tracking, with the force value which changes during the movement of adjustment depending on the mechanical system.

Abstract: A lid assembly for a container includes a lid engaging device, a transmission assembly mounted on the lid engaging device, and a lid including a first pivotal section and a second pivotal section disposed opposed to each other. The first and second pivotal sections define an imaginary axis “A” extended therebetween, and the first and second pivotal sections are mounted on the lid engaging device. The first pivotal section is engaged with the transmission assembly. The lid is pivoted automatically by the transmission assembly. The lid is pivotal about the imaginary axis “A” and is moveable between an open position that enables items to be put in the container and a closed position in which the lid prevents items to be put in the container.

Abstract: A fan for a ventilation system has a motor, a motor speed control unit and a controller arranged to control the motor to maintain the quantity of air flowing through the system constant. The controller compares the actual motor current with an expected motor current for the fan operating at the desired air quantity and motor speed to determine an actual system operating condition. When the difference between the actual motor current and the expected motor current is greater than a preset range, the motor speed is adjusted to a new motor speed determined based on the actual system operating condition. The system operating conditions may change due to changes in the static pressure of the system such as changes to the ventilation ducting or external wind pressure.

Abstract: There is provided a control system for an electric motor to which electric power is supplied from a DC power supply via a multi-phase inverter, the multi-phase inverter including switch units respectively provided on a positive side and a negative side of arms corresponding to respective phases, each switch unit including a switching element and a reflux diode connected in parallel thereto. The control system comprises a phase current detection unit for detecting phase currents which flow between the inverter and the electric motor, a DC component acquiring unit for acquiring DC components of the respective phase currents, and a short-circuiting determination unit for determining that a short-circuit failure occurs in the inverter when at least one of the DC components of the phase currents acquired by the DC component acquiring unit exceeds a threshold. Consequently, the short-circuit failure of the inverter can be detected even though the control of the electric motor is stopped.

Abstract: A mode determination circuit is configured to determine whether there is a status change of the electric system associated with a frequency variation of a system control clock, and a clock change circuit is configured to change the system control clock from a system clock to a monitoring clock based on a determination result obtained by the mode determination circuit.