Abstract: Proposed is a motor control device that executes rotational control that follows load fluctuations in a startup mode. The proposed motor control device is provided with: detection means 4 that detects a current peak value Ip and a current electrical angle ?i based on phase currents Iu to Iw; detection means 5 that detects an induced voltage peak value Ep and an induced voltage electrical angle ?e based on phase currents Iu to Iw and applied voltages Vu to Vw; rotor position detection means 6 that detects a rotor position ?m using ?m=?i???90° or ?m=?e???90°; velocity fluctuation detection means 15 that detects a rotational velocity ? based on this ?m; and startup means 10 that outputs a startup voltage instruction value Vp and a startup voltage phase instruction value ?v, increases the rotational velocity of the synchronous motor M with predetermined acceleration, and makes the rotational velocity ? detected by the velocity fluctuation detection means 15 be reflected in ?v.

Abstract: The present invention relates to a motor control device provided with the function of detecting the rotor position of a synchronous motor in a sensor-less fashion. The motor control device previously stores a current phase ? defined by the two parameters that are an induced voltage peak value Ep and the subtracted value (?e??i) obtained by subtracting an induced voltage electrical angle ?e from a current electrical angle ?i, and based on the actual detected Ep, ?i, and ?e, selects ? by referring to the ? previously stored, and calculates the rotor position ?m by subtracting the selected ? from the actual detected ?i. Then, in case of selecting ?, the actual detected Ep and ?e are corrected according to changes in the current flowing through the coil. As a result, a detection accuracy for the rotor position during a transition period is enhanced.

Abstract: The present invention includes: an electrolytic capacitor that smoothes a rectified voltage to a direct voltage; an inverter circuit that generates an alternating voltage from the direct voltage, to drive an electric motor; a controlling device that controls drive of switching elements included in the inverter circuit; and a temperature measuring device that measures a temperature of the electrolytic capacitor, to output the measured temperature to the controlling device, in which, when the temperature obtained by the temperature measuring device is lower than a predetermined target temperature, the controlling device supplies the electric motor with a current which is restricted so that a ripple voltage of the direct voltage falls within an allowable range, before starting a normal operation of the electric motor, so that the temperature of the electrolytic capacitor is raised to the target temperature. Thus, the electrolytic capacitor can be used even in a lower-temperature environment.

Abstract: Phase voltage setting means defines an actual current phase region including a current phase error range based on parameters including an individual difference of at least any one of a motor and an inverter, defines a stable operation current phase region in which a rotor position can be detected through sensorless control, and sets, as a target current, an electric current obtained by adding a predetermined phase difference corresponding to the number of revolutions detected by revolution number detecting means to an electric current set by current vector control such that the actual current phase region is within the stable operation current phase region.

Abstract: It is an object of the present invention to provide a motor control device that can improve stability of sensorless control of a permanent magnetic synchronous motor. Rotor position detecting means (10) includes motor parameter correcting means (30) for correcting a parameter (winding resistance of a coil, a magnetic flux amount of a permanent magnet), which is a machine constant of a motor, in order to eliminate an induced voltage difference between a detected induced voltage peak value and a detected estimated induced voltage peak value and detects the rotor position on the basis of the corrected parameter.

Abstract: A device controls power supplied from an inverter having a semiconductor switching element to an electric compressor having an external drive source or a built-in motor. The device includes: an apparatus for calculating a starting current value required for starting the compressor from the pressure at the discharge side circuit of the compressor; an apparatus for calculating a permitted current value of the semiconductor switching element from the temperature of the inverter installation portion; and an apparatus for comparing the calculated compressor starting current value to the permitted current value of the semiconductor switching element so as to determine whether to permit a start of the compressor.

Abstract: A motor control device includes feed-forward control means for detecting a change amount of a predetermined monitoring target, which is used for changing the number of revolutions of a motor without depending on revolution number detecting means, and correcting the number of revolutions recognized by a controller.

Abstract: Problems to be Solved To provide is a motor control device capable of detecting a rotor position of a synchronous motor under a certain accuracy and a low processing load. Means for Solving the Problems The motor control device detects the rotor position ?m by directly finding a rotor position ?m from a rotor position expression (?m=?i???90°) containing, as a variable, a current electrical angle ?i from among a phase current peak value Ip and a phase current electrical angle ?i detected in a phase current peak value and electrical angle detection unit 19 and an induced voltage peak value Ep and an induced voltage electrical angle ?e detected in an induced voltage peak value and electrical angle detection unit 20, and containing, as a variable, a current phase ? capable of being selected using [a phase current peak value Ip] and [an induced voltage electrical angle ?e?a phase current electrical angle ?i] as parameters from a predefined data table.

Abstract: PROBLEMS TO BE SOLVED To provide a motor control device that can diagnose an abnormality in overcurrent detection means and can previously avoid various problems caused by the abnormality MEANS FOR SOLVING THE PROBLEMS The motor control device has an overcurrent test unit 19 to send a first test voltage Vt1 lower than a reference voltage Vref for overcurrent determination and a second test voltage Vt2 not lower than the reference voltage Vref to an overcurrent determination unit 18 when a synchronous motor 11 is not rotated. The motor control device determine that an abnormality occurs in the overcurrent detection unit 18 when the overcurrent determination unit 18 determines that the first test voltage Vt1 from the overcurrent test unit 19 causes no overcurrent on the basis of a comparison result, or when the overcurrent determination unit 18 determines that the second test voltage Vt2 from the overcurrent test unit 19 causes an overcurrent on the basis of a comparison result.

Abstract: An inverter apparatus comprises an inverter circuit using pairs of switching elements. The pseudo AC voltage of each phase of this inverter circuit is controlled by pulse modulation using pulses generated by a PWM generator, and the pseudo AC voltages are applied to a power supplied load. The average voltage of respective phases of the output voltages applied to the power supplied load is detected as a virtual neutral voltage corresponding to the neutral voltage of the power supplied load by detecting the voltage at a common node where the phases of a voltage detecting circuit provided between the inverter circuit and the power supplied load are connected. The detected virtual neutral voltage is fed back for controlling the output duty of each phase by the PWM generator. Thus the output voltage of each phase from the inverter circuit is controlled so as to become a target output voltage. The target output voltage can be accurately obtained stably at all times.

Abstract: Provided is a device for controlling power supply from an inverter having a semiconductor switching element to an electric compressor having a built-in motor. The device includes: means for calculating a starting current value required for starting the compressor from the pressure at the discharge side circuit of the compressor; means for calculating a permitted current value of the semiconductor switching element from the temperature of the inverter installation portion; and means for comparing the calculated compressor starting current value to the permitted current value of the semiconductor switching element so as todetermine whether to permit a start of the compressor. Thus, it is possible to appropriately start the electric compressor without using a semiconductor switching element requiring a greater current capacity than is necessary in the inverter. This reduces the size and the cost of the electric compressor.

Abstract: An inverter apparatus comprises an inverter circuit using pairs of switching elements. The pseudo AC voltage of each phase of this inverter circuit is controlled by pulse modulation using pulses generated by a PWM generator, and the pseudo AC voltages are applied to a power supplied load. The average voltage of respective phases of the output voltages applied to the power supplied load is detected as a virtual neutral voltage corresponding to the neutral voltage of the power supplied load by detecting the voltage at a common node where the phases of a voltage detecting circuit provided between the inverter circuit and the power supplied load are connected. The detected virtual neutral voltage is fed back for controlling the output duty of each phase by the PWM generator. Thus the output voltage of each phase from the inverter circuit is controlled so as to become a target output voltage. The target output voltage can be accurately obtained stably at all times.

Abstract: An inverter unit includes a DC power source, an inverter circuit having two or more pairs of switching elements which are connected in parallel to the DC power source, so that a DC voltage of the DC power source is converted into a pulse train-like, pseudo-AC voltage output from the inverter circuit, and a PWM generator connected to the inverter circuit for adjusting the pseudo-AC voltage by pulse width modulation. Further, the inverter unit includes a voltmeter for detecting an actual, output voltage which is output from the inverter circuit, and a duty cycle controller for controlling an output duty cycle, so that the detected, actual, output voltage becomes a target output voltage. In this inverter unit, a desirable, output voltage may be obtained stably and accurately even if a voltage of a power source fluctuates.

Abstract: An inverter unit includes a DC power source, an inverter circuit having two or more pairs of switching elements which are connected in parallel to the DC power source, so that a DC voltage of the DC power source is converted into a pulse train-like, pseudo-AC voltage output from the inverter circuit, and a PWM generator connected to the inverter circuit for adjusting the pseudo-AC voltage by pulse width modulation. Further, the inverter unit includes a voltmeter for detecting an actual, output voltage which is output from the inverter circuit, and a duty cycle controller for controlling an output duty cycle, so that the detected, actual, output voltage becomes a target output voltage. In this inverter unit, a desirable, output voltage may be obtained stably and accurately even if a voltage of a power source fluctuates.

Abstract: A current detection unit of an inverter outputs currents to a load, such as a motor includes a device for measuring a DC current flowing in the inverter. The current detection unit also includes a measurement time setting device for setting a measurement time of power source currents at at least one of an uppermost point and a lowest point of a reference chopping wave with a predetermined frequency, and a current phase detection means for detecting at least two phase currents from respective power source currents measured at two or more measurement times sequential to each other. A phased current output from the inverter to a load, such as a motor, may be detected with a high degree of accuracy and at a constant period.

Abstract: A motor control apparatus capable of easily and reliably determining the completion of starting of a synchronous motor and not requiring an arithmetic unit having high processing ability for the determination. When an operation command including a predetermined target rotation speed is received in a state where the motor is at rest, PWM signals are created on the basis of a starting voltage set by a starting voltage setting section and a starting phase set by a starting phase setting section, whereby the motor is started. After the start of the motor, a starting rotation speed setting section makes the processing to increase the starting rotation speed. When the starting rotation speed reaches a predetermined value smaller than the target rotation speed, it is determined that the starting is completed, and a shift is made from starting operation to normal operation.

Abstract: A motor control apparatus includes a phase current detecting section for detecting phase currents to a motor, a current phase/current peak value calculating section for calculating a current phase based on the phase currents, a voltage phase setting section for adding a predetermined phase difference to the current phase and setting the resultant sum as a voltage phase, a phase voltage setting section for setting phase voltages to the motor based on the voltage phase and the command voltage. Basically, the motor is operated by maintaining the voltage at constant and always monitoring the current/voltage phases so as to maintain a constant phase difference, without the motor axis position being predicted.

Abstract: A motor control apparatus capable of easily and reliably determining the completion of starting of a synchronous motor and not requiring an arithmetic unit having high processing ability for the determination. When an operation command including a predetermined target rotation speed is received in a state where the motor is at rest, PWM signals are created on the basis of a starting voltage set by a starting voltage setting section and a starting phase set by a starting phase setting section, whereby the motor is started. After the start of the motor, a starting rotation speed setting section makes the processing to increase the starting rotation speed. When the starting rotation speed reaches a predetermined value smaller than the target rotation speed, it is determined that the starting is completed, and a shift is made from starting operation to normal operation.

Abstract: A motor control system includes a control section that performs operating range limiting processing in which a junction temperature of switching element of an electric power converter is calculated and compared with a preset temperature limit, and when the junction temperature exceeds the temperature limit, junction temperature reduction processing is performed to make the junction temperature equal to or less than the temperature limit, whereby the switching elements can effectively used to their maximum temperature limit irrespective of a temperature detected by a temperature sensor, thus expanding the operating range of a motor.

Abstract: A current detection unit of an inverter outputs currents to a load, such as a motor includes a device for measuring a DC current flowing in the inverter. The current detection unit also includes a measurement time setting device for setting a measurement time of power source currents at at least one of an uppermost point and a lowest point of a reference chopping wave with a predetermined frequency, and a current phase detection means for detecting at least two phase currents from respective power source currents measured at two or more measurement times sequential to each other. A phased current output from the inverter to a load, such as a motor, may be detected with a high degree of accuracy and at a constant period.