Abstract: A surge current protection circuit, has a control unit having an output end, a photoelectric coupling and driving circuit, a silicon symmetrical switch having a control end, and a current-limiting resistor. The current-limiting resistor and the silicon symmetrical switch are parallel connected altogether and then serially connected to a load and an AC input, and the control end of the silicon symmetrical switch is connected to the output end of the control unit via the photoelectric coupling and driving circuit. The invention features low production cost, high reliability and improved power efficiency, and is capable of effectively suppressing surge current.

Abstract: An input circuit includes an interface structured to output a logic signal from an alternating current signal of a pair of elongated conductors. A load is switchable to the elongated conductors. A processor outputs a control signal to switch the load to the elongated conductors asynchronously with respect to the alternating current signal for a first predetermined time, inputs the logic signal, determines if the input logic signal is active a plurality of times during the first predetermined time and responsively sets a first state of the alternating current signal, and, otherwise, sets an opposite second state of the alternating current signal, and delays for a second predetermined time, which is longer than the first predetermined time, for the opposite second state before repeating the output, and, otherwise, delays for a third predetermined time, which is longer than the second predetermined time, for the first state before repeating the output.

Abstract: For each phase of a controller, semiconductor switches comprise a high side switch and a low side switch. A direct current voltage bus provides electrical energy to the semiconductor switches. A measuring circuit is adapted to measure the collector-emitter voltage or drain-source voltage for each semiconductor switch of the controller. A data processor determines that a short circuit in a particular semiconductor switch is present if the measured collector-emitter voltage or measured source-drain voltage for the particular semiconductor switch is lower than a minimum threshold and if an observed current associated with the particular semiconductor switch has an opposite polarity from a normal operational polarity. A driver simultaneously activates counterpart switches of like direct current input polarity that are coupled to other phase windings of the electric motor, other than the particular semiconductor switch, to protect the electric motor from potential damage associated with asymmetric current flow.

Abstract: A power conversion apparatus of an electric vehicle includes: a power converter for driving an induction machine based on arbitrary d- and q-axis voltage commands Vd* and Vq*, and a control unit for controlling the power converter based on a power running command P and a brake command B from outside.

Abstract: A motor control device includes: a motor control unit; and a signal output unit, the motor control unit includes: a first control unit configured to estimate a current upper limit value on the basis of the rotation speed of the motor and a current decrease caused by back electromotive force, the first control unit configured to determine a control input corresponding to the estimated current upper limit value, and a second control unit configured to determine a control input to be applied to the motor on the basis of an operation amount of the motor and a target value of the operation amount to control the motor, and in the early period of driving of the motor, the motor is controlled by the first control unit, and in the late period of driving of the motor, the motor is controlled by the second control unit.

Abstract: A motor driving device for protecting inrush current is disclosed, where the motor driving device includes a resistor, a capacitor, an electronic switch, a rectifier and a driving circuit. The capacitor is connected to the resistor in series. The electronic switch is connected to the resistor in parallel. The rectifier is connected to the resistor and the capacitor in parallel and is electrically connected to a power source. The driving circuit is connected to the resistor and the capacitor in parallel and is electrically connected to a motor.

Abstract: A motor drive control device is provided in which if any abnormality occurs in a drive control circuit, drive command signals the drive control circuit generates are interrupted at once, so that an AC motor can be stopped in safety. A monitor control circuit and drive command signal interruption circuit are provided to the drive control circuit that takes variable-speed control of the AC motor supplied with power from a DC drive power source via a semiconductor bridge circuit. If any abnormality occurs in the drive control circuit, the drive command signals the drive control circuit generates are interrupted at once. When starting operation, the drive control circuit and monitor control circuit cooperate with each other to conduct preliminary check as to whether or not the drive command signal interruption circuit operates normally, base on a predetermined time schedule, and stop the AC motor without fail if any abnormality occurs during operation.

Abstract: An electronically commutated pump motor circuit comprises an input configured, to receive at least a first range of voltages, and a power conditioning circuit. The power conditioning circuit includes an active power factor correction circuit, coupled to the input. The power conditioning circuit is configured to receive the first range of voltages and automatically output to an electronically commutated motor (optionally a pump motor) a substantially constant DC voltage for input voltages within the first range of input voltages, boosted with respect to a voltage received at the input, to thereby maintain a substantially constant motor shaft speed for any voltage within the first range of voltages.

Abstract: A system and method for a vehicle control system is disclosed herein. The system includes an inverter circuit, a permanent magnet synchronous motor, and a crossover connected between the inverter circuit and the permanent magnet synchronous motor. The system may also include at least one current sensor installed between the inverter circuit and the permanent magnet synchronous motor. A contactor may also be connected between the inverter circuit and the permanent magnet synchronous motor and may pass or shut off electricity between the inverter circuit and the permanent magnet synchronous motor. The system may also include a control unit connected to the contactor and the current sensor. The control unit may detect a current abnormality using information from the current sensor and open the contactor if an abnormality is detected.

Abstract: Example embodiments disclose an Interior Permanent Magnet (IPM) machine system including an IPM machine including a nominal operating direct current (dc) bus voltage, and a controller configured to detect an operating dc bus voltage of the IPM machine and to control the IPM machine based on the nominal operating dc bus voltage and the detected operating dc bus voltage.

Abstract: When a failure detection part detects a failure in an inverter circuit in a first power supply system, a drive control part stops the inverter circuit from driving a motor. An on/off control part turns off a first power supply relay of a power supply on/off part. Under a state that the inverter circuit stops a motor driving operation, a first coil set of the motor generates an induced voltage by rotation caused by an external force. The induced voltage is regenerated to a battery from the inverter circuit through a second power supply relay and a parasitic diode of the first power supply relay. Thus, circuit elements in the power supply system, which is failing, are protected from breaking down.

Abstract: A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value corrector 26 corrects the d-axis and q-axis current target values id*, iq* by the field weakening control such that d-axis and q-axis voltages vd, vq and d-axis and q-axis currents id, iq satisfy ?(vd2+vq2)?Vlim and ?(id2+iq2)?Ilim respectively. The d-axis and q-axis current command values idc, iqc are obtained by this correction.

Abstract: In a motor control device that is used for, for example, an electric power steering system or another vehicle steering system equipped with a motor, a relay circuit (40) that serves as a power supply breaker is provided in a power feed line (Lp2) of a pre-driver (22) of a circuit that is a component of the motor control device. The operation of the relay circuit (40) is controlled by a relay signal (S_rly) output from a microcomputer (21).

Abstract: A motor drive circuit includes a positive and a negative supply rail for connection to a battery (104), a motor drive circuit including a plurality of motor drive subcircuits which each selectively permit current to flow into or out of a respective phase of a multi-phase motor (101) in response to control signals from a motor control circuit, and a switching means including at least one switch which is in series with a respective phase of the motor which is normally closed to permit the flow of current to and from the subcircuit to the respective motor phase. A fault signal detecting means (160) detects at least one fault condition and, in the event of a fault condition being detected, causes the at least one switch to open. A snubber circuit (150) is associated with the motor and is arranged so that following the opening of the switch, energy stored in the motor windings is diverted away from the switching means through the snubber circuit to the battery.

Abstract: A motor control system includes a control module, a switching module, and a filtering module. The control module determines output voltages for operating a motor based on a torque demand. The switching module generates switching signals for an inverter that drives the motor. The switching module generates the switching signals based on the output voltages. The switching module generates an out-of-volts (OOV) signal according to a comparison based on the output voltages, a maximum duty cycle, and a voltage of a direct current (DC) bus that provides power to the inverter. The filtering module generates an OOV amount by filtering the OOV signal. The control module selectively limits the torque demand based on the OOV amount.

Abstract: A drive system for an electric motor includes a connection for a battery, and an inverter having an input side connected to an intermediate circuit and an output side having a connection for an electric motor. The intermediate circuit includes a first thyristor connected in parallel with an intermediate circuit capacitance. The drive system may also include a rectifier having an input side connected at the output side of the inverter in parallel with the electric motor, and a second thyristor connected an output side of the rectifier. The first/second thyristor are configured to be activated by a monitor incorporated in or assigned to the drive system. In the event of a malfunction, the input and/or output side of the inverter can be electrically isolated to allow a multiply redundant armature short circuit.

Abstract: A self-adapting soft-starter device includes an electric current limiter limiting electric current supplied to the motor to a preset maximum current limit, a ramp-up time determiner determining the actual ramp-up time of the electric motor, a storing device storing a preset minimum ramp-up time, a comparator comparing the determined actual ramp-up time with the preset reference ramp-up time, a replacing device replacing the preset maximum current limit with an auto-adapted current limit based upon the outcome of the comparison between the determined actual ramp-up time and the preset reference ramp-up time. The soft-starter automatically optimizes the maximum current limit driven by the motor to match its load requirements which is useful to cater for load variations with time during the lifetime of the product in the application by avoiding the need for human intervention to change the soft-starter settings. Wear and tear is also reduced, extending motor lifetime.

Abstract: A MG-ECU is provided in a hybrid vehicle having an MG and an engine and starts the engine by controlling the MG. When the MG-ECU detects a disconnection in any one of three-phase power supply wires, which supply the MG with power, the MG-ECU permits driving of the MG on condition that the engine is requested to be started. The MG-ECU limits a command torque for the MG is limited to be equal to or less than a predetermined torque value than in a case of presence of no disconnection, when the MG is permitted to be driven.

Abstract: In a motor controller, a current detection unit detects an electric current flowing through a brushless motor. An open loop control unit determines a command value indicating a level of a command voltage in accordance with a motor circuit equation, based on a command current value indicating an amount of electric current to be supplied to the brushless motor and an angular velocity of a rotor in the brushless motor. A correction unit calculates a correction value based on a difference between the command current value and a current value detected by the current detection unit when the electric current is detected by the current detection unit and corrects the command value according to the correction value, and corrects the command value according to the correction value even when an electric current is not detected by the current detection unit.

Abstract: A motor drive device includes a drive controller for generating drive signal “trq”, a limiter for limiting a value of drive signal “trq” within a range, a limit value generator for generating limit value “lmt”, and a drive output section for generating an energizing signal in response to an output signal from the limiter. The limit value generator generates a comparison signal by adding offset value “ofs” to drive signal “trq” and updates limit value “lmt” based on a size relation between a value (trq+ofs) of the comparison signal and limit value “lmt”.

Abstract: A mechanism for assigning unique addresses to identical devices attached to a serial bus is presented. Each device has at least one output and is provided with a storage device to provide a configurable portion of a bus address having a fixed portion and a configurable portion. The device is further provided with circuitry, coupled to the storage device and the output, to determine a state of the output and use the state to configure the configurable portion. Once the configurable portion is configured, the bus address uniquely identifies the device. Such configuration allows more than one such device to be coupled to the same serial bus, e.g., an I2C bus.

Abstract: A control system for a motor includes a current regulation controller for generating a terminal voltage command. The terminal voltage command is used for converting a supply voltage to a three phase voltage to power a motor. The control system also includes a terminal voltage command feedback module for controlling the terminal voltage command. The terminal voltage command feedback module compares the terminal voltage command to a determined voltage limit of the supply voltage and generates a d-axis current adjustment command in accordance with the comparison. The d-axis current adjustment command is used for reducing the terminal voltage command below the determined voltage limit. The control system also includes a summer coupled with the terminal voltage command feedback module. The summer adds the d-axis current adjustment command to a d-axis current command received from a lookup table.

Abstract: According to one illustrative embodiment, a washing machine comprises a motor including a plurality of coils and one or more permanent magnets, an inverter configured to supply current to the plurality of coils and to measure a back electromotive force (BEMF) waveform from the plurality of coils, and an electronic control unit (ECU) configured to (i) integrate the BEMF waveform to generate an integrated BEMF waveform, (ii) determine a magnetic flux of the one or more permanent magnets using an amplitude of the integrated BEMF waveform, and (iii) control the current supplied by the inverter based at least in part upon the determined magnetic flux.

Abstract: A method for monitoring input power to an electronically commutated motor (ECM) is described. The method includes determining, with a processing device, an average input current to the motor, the average input current based on a voltage drop across a shunt resistor in series with the motor, measuring an average input voltage applied to the motor utilizing the processing device, multiplying the average input current by the average voltage to determine an approximate input power, and communicating the average input power to an external interface.

Abstract: A motor drive apparatus includes a control circuit, which determines that a wire connecting a battery to a first power supply relay and a second power supply relay is broken, and not failure of the power supply relays, if power is not supplied to a motor from the power supply relays when the power supply relays are controlled to turn on. The location of failure can thus be specified accurately. It is only necessary in this case to replace the wire. The motor drive apparatus need not be disassembled or investigated in detail. Man-power for specifying the failure location can be reduced.

Abstract: A brushless fan motor control circuit assembly consists of a high-frequency filter circuit, a rectifier circuit, a power factor enhancing circuit, a current-limit and voltage regulation circuit and a brushless fan motor driving circuit. By means of the high-frequency filter circuit to suppress high frequency noises, the power factor enhancing circuit to enhance the power factor and to save power consumption, the current-limit and voltage regulation circuit to limit the current and to achieve overload protection, the brushless fan motor control circuit assembly controls the operation of a motor of an electric accurately and safely, avoiding fan vibration.

Abstract: A motor driving device includes a converter that converts an input alternating current into a direct current, an inverter that inverts the direct current output by the converter into an alternating current for driving a motor, a voltage detecting unit that detects a voltage on a direct current output side of the converter, and a numerical control unit that causes the inverter to output a reactive current to increase electric power consumed in the motor, when the voltage detected by the voltage detecting unit exceeds a predetermined threshold.

Abstract: Systems, methods and computer program products for reducing or removing current spikes generated during a current recirculation period associated with phase switching in a spindle motor are described. In some implementations, the duty cycle of the drive signals applied to the windings of the spindle motor can be adjusted to reduce or eliminate the current surge resulting from current recirculation. In some implementations, the duty cycle of the drive signals during spin-up can be reduced based on a current limit, and the reduced duty cycle can then be used to drive the spindle motor taking into account of current surges in the supply current.

Abstract: Provided is a regenerative switched reluctance motor driving system which allows a motor to have a reduced size and weight and an increased efficiency as well as improved energy recovery efficiency at the time of regenerative braking without using a neodymium magnet. Based on an angular position of a rotor in the motor, a constant current flip-flop circuit 2 renders two current paths alternately conductive so as to allow a rectangular-wave current having a width of an electrical angle of 180° to alternately flow in two coils in the motor 3, and shifts the timing of rendering the two current paths alternately conductive, between when driving and when braking the motor 3, by a time during which the rotor is rotated by an angle corresponding to an electrical angle of 180°.

Abstract: A control system for an electric machine, the control system including a current controller and a drive controller. The current controller includes an input, an output, a comparator and a latch. The comparator sets the latch when a voltage at the input exceeds a threshold, and the latch outputs an overcurrent signal when set. The drive controller then resets the latch after a predetermined period of time.

Abstract: A first terminal of a protection element of a control unit is connected to a wire between a motor and a switching element, and a second terminal is directly connected to a ground-side wire shared by a controller and the switching element. The protection element has a normal-condition-OFF-type switch including a movable contact and a fixed contact. When an overheating caused by the switching element attains a predetermined temperature or higher, the movable contact and the fixed contact are closed to short-circuit the first terminal and the second terminal, and an electric current is branched to the protection element side to reduce an electric current flowing into the switching element, and the control unit is shifted to a temperature range safe from the overheating caused by the switching element without stopping a cooling system.

Abstract: The disclosed device comprises a duty calculator for calculating a duty command value (Dty), a duty limiter for limiting the duty command value (Dty) to a value according to a limit value (L), a current flow monitor for determining that there is an overcurrent if a current value (Idet) flowing through a winding exceeds a predetermined threshold value (Ithr), and a limit value generator for generating the limit value (L). The limit value generator updates the limit value (L) at predetermined time intervals and for a value corresponding to a difference between the threshold value (Ithr) and the current value (Idet) at a time in order to decrease the current value (Idet) during a period in which the overcurrent is determined.

Abstract: A first inverter and a second inverter supply two coil sets forming a three-phase motor with AC voltages, which are the same in amplitude but shifted by 30° in phase. Current detectors detect phase currents supplied from the inverters to the coil sets. Temperature estimation sections estimate temperatures of the inverters or the coil sets based on an integration value of the phase current detection values. A current command value limitation section limits upper limits of current command values of both coil sets based on the estimated temperatures Tm1 and Tm2. Thus, the inverters and the coils sets are protected from overheating without increasing torque ripple.

Abstract: A fan system circuit module including a stable voltage input terminal for receiving a stable voltage, an operation unit electrically connected to the stable voltage input terminal and a drive chip. The operation unit includes a first resistor, a second resistor, a first capacitor and a third resistor. After powered on at the stable voltage, the operation unit generates an operation signal for the drive chip to decrease drive current value of the fan. In case that a lock of the fan takes place, the drive chip can effectively decrease the block current. The circuit module has soft-start function and provides block current protection effect so as to avoid malfunctioning of the fan system due to too great start current of the fan and avoid burnout of the fan due to high rise of temperature.

Abstract: There is provided a control device of a permanent-magnet type synchronous motor that sets a synchronous operation current at start-up in response to a current limiting value determined from the temperature of an inverter that supplies three-phase power to the permanent-magnet type synchronous motor, that monitors an output voltage or an output current of the inverter during a rotation stabilizing period after start-up, and that updates the synchronous operation current using this output voltage or output current.

Abstract: A pump system. The pump system includes a pump, a motor coupled to the pump, a sensor coupled to a power source, and a controller. The motor operates the pump. The sensor detects an electrical characteristic of the power source. The controller executes a fault check, controls the motor, detects a change in the electrical characteristic, and suspends the execution of the fault check for a predetermined period of time when the detected change in the electrical characteristic is outside of a valid characteristic range.

Abstract: In a voltage booster apparatus, a charge control transistor is turned on to charge a coil output capacitor and a booster output capacitor and then turned off, thereby confirming rise of a coil output voltage and a booster output voltage. A power supply relay is turned on to restore a booster operation thereby to check rise of the booster output voltage. If both of a step-up FET and a step-down FET are not in short-circuit failure, ON state of the power supply relay is fixed thereby to restore a power steering system operation.

Abstract: A switching system includes a plurality of diodes forming a diode bridge, and a micro-mechanical system (MEMS) switch array closely coupled to the plurality of diodes. The MEMS switch array is electrically connected in an (M×N) array. The (M×N) array includes a first MEMS switch leg electrically connected in parallel with a second MEMS switch leg. The first MEMS switch leg includes a first plurality of MEMS dies electrically connected in series, and the second MEMS switch leg includes a second plurality of MEMS dies electrically connected in series.

Abstract: The invention relates to a circuit arrangement for the selective operation of at least two electric machines (1, 2) that are each supplied via a plurality of phase lines, comprising:—one voltage protection module (5) for limiting an intermediate circuit voltage,—one switch arrangement (4) for selecting one of the electric machines by switching the phase lines;—first choke inductivities (8) in each of the plurality of phase lines between the circuit arrangement (4) and the voltage protection module (5), wherein one second choke inductivity (9?) each may be switched parallel to one or more first choke inductivities (8) as a function of the selected electric machine (1, 2), can be switched.

Abstract: A rotating electrical machine includes a DC power supply; a rotating electrical machine; an inverter provided between the DC power supply and the rotating electrical machine to control current flowing in the rotating electrical machine; and a control device that: determines a rotational speed as a rotational speed requested for the rotating electrical machine and a requested torque as a torque requested for the rotating electrical machine; and limits a torque of the rotating electrical machine. The inverter is operated based on the rotational speed and the requested torque determined by the control device, and the control unit changes a limit of the torque in accordance with an inverter voltage which is a voltage applied to a frequency conversion portion provided in the inverter.

Abstract: A component intended for use in very low temperature situations has an electromechanical actuator with a control for an electric motor. The control receives a temperature signal indicative of a temperature being experienced by the electromechanical actuator. The control is operable to produce a current signal sent to the electric motor which will generate heat without significant torque. A method of operating the electromechanical actuator is also disclosed.

Abstract: An electronically commutated one-phase motor (20; 20?) has a stator having at least one winding strand (30, 32; 30?), and it has a permanent-magnet rotor (22) that induces, as it rotates, a voltage (uind) in the winding strand. The motor further has an electronic calculation device or microcontroller (26) which is configured to execute, during operation, the following steps repetitively: sampling the induced voltage (uind) in a currentless winding strand, for example, during a half-wave of the induced voltage, in order to obtain a plurality of analog voltage values; digitizing the analog voltage values in order to obtain a plurality of digitized voltage values; and processing the plurality of digitized voltage values to ascertain the instantaneous rotation direction of the motor rotor. The control circuit then can use these data to assure reliable motor start-up, regardless of any external driving forces which occur.

Abstract: When a fault of any one of phases is detected by a fault detector, each of the phases is checked for fault on the basis of fault detection information input to a controller, and the phases of normal phase currents which have been judged to be not faulty by a faulty phase discriminator are varied such that a current vector obtained by decomposing the normal phase currents into orthogonal X- and Y-axis components to derive resultant currents and then combining the resultant currents follows a nearly circular locus.

Abstract: A data processing apparatus that controls an inverter circuit for a motor. The data processing apparatus including a control unit that monitors a potential of a power supply terminal to supply power to the inverter circuit, and obtains an information indicative of an amount of a driving current flowing in a motor winding of the motor in response to an amount of a current flowing in a resistive element included in the inverter circuit, to control a driving of the motor. The control unit makes the motor winding and the resistive element form a loop circuit, when the potential of the power supply terminal exceeds a predetermined value.

Abstract: In configuring a power conversion device to drive an alternating-current motor for an electric vehicle, the device is configured in a small size, light weight, and at a low cost, while avoiding size increase of a cooler. A current-command generating unit provided in a controller to control the alternating-current motor is adjusted not to increase a loss of an inverter in a state that the inverter as a main circuit within the power conversion device is outputting a maximum voltage that can be generated at an output voltage of a direct-current power source and when a torque command is reduced, and outputs a current command to cause the alternating-current motor to generate a torque based on the torque command.

Abstract: An inverter includes a voltage command generator generating a voltage command value according to an externally specified voltage value, a PWM signal generator generating a PWM signal according to the voltage command value and frequency command value, and a switching unit generating a three-phase AC power according to the PWM signal. The voltage command generator decreases the voltage command value if the output current increases, to prevent the rotation speed of a prime move from suddenly changing. If the output current exceeds a preset upper current threshold, the voltage command value is clamped at a preset minimum output voltage, thereby securing the minimum output voltage for an increase in the output current.

Abstract: A control system for a motor includes a current regulation controller for generating a terminal voltage command. The terminal voltage command is used for converting a supply voltage to a three phase voltage to power a motor. The control system also includes a terminal voltage command feedback module for controlling the terminal voltage command. The terminal voltage command feedback module compares the terminal voltage command to a determined voltage limit of the supply voltage and generates a d-axis current adjustment command in accordance with the comparison. The d-axis current adjustment command is used for reducing the terminal voltage command below the determined voltage limit. The control system also includes a summer coupled with the terminal voltage command feedback module. The summer adds the d-axis current adjustment command to a d-axis current command received from a lookup table.

Abstract: A brushless DC motor having a plurality of electrical windings and a control circuit operatively connected thereto. The control circuit includes a plurality of switches configured for a time-dependent application of an electrical voltage from an external voltage supply to the windings. A measuring device is also provided for generating an electrical signal depending on the current flow IB from the external voltage supply through the control circuit. An overcurrent fuse is further provided for protecting the control circuit and the windings. In order to achieve particularly high integration of the control circuit, the invention proposes supplying a voltage drop across the overcurrent fuse to the measuring device as an input value.

Abstract: A motor system comprises a motor (3), wherein the ratio of the number of armature magnetic poles of a stator (53), the number of magnetic poles of a first rotor (51), and the number of cores of a second rotor (52) is set to 1:m:(1+m)/2, and en ECU (60) that generates a d-axis voltage command value (Vd—c) and a q-axis voltage command (Vq—c) according to a torque command value (Tr_c), and corrects the voltage command values so as to generate a magnetic field weakening current which reduces the magnetic flex of the magnetic poles of the first rotor when the magnitude of the vector sum of the voltage command values is greater than an upper voltage limit (Vulmt) set according to an output voltage (Vo) of a battery (11).

Abstract: A motor control device is configured in such a manner that a current detection circuit and an exciting circuit for a motor resolver share one grounding wire. A microcomputer that serves as a current detector sets a phase of an exciting current in such a manner that values of an excitation noise superimposed on an output voltage of the current detection circuit at respective timings (L1, H1, L2, H2, . . . ), at which the output voltage is acquired in one current detection process, are equal to each other. An electric power steering system is provided with the motor control device.