摘要:
A phase voltage setting unit is configured to define an actual current phase region including a current phase error range based on parameters to which is added an individual difference of at least any one of a motor and an inverter. The phase voltage setting unit 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 phase difference corresponding to the number of revolutions detected by the revolution number detecting unit to an electric current set by current vector control, such that the actual current phase region is within the stable operation current phase region.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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 β defined by the two parameters that are an induced voltage peak value Ep and the subtracted value (θe−θi) obtained by subtracting an induced voltage electrical angle θe from a current electrical angle θi, and based on the actual detected Ep, θi, and θe, selects β by referring to the β previously stored, and calculates the rotor position θm by subtracting the selected β from the actual detected θi. Then, in case of selecting β, the actual detected Ep and θe 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.
摘要:
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.
摘要:
PROBLEMS TO BE SOLVEDTo provide a motor control device that can diagnose an abnormality in overcurrent detection means and can previously avoid various problems caused by the abnormalityMEANS FOR SOLVING THE PROBLEMSThe 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.
摘要:
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.
摘要:
An applied-voltage electrical angle setting method for a synchronous motor includes detecting applied voltage and current of the synchronous motor M, calculating current peak value Ip based on the detected values while calculating present applied voltage phase α, calculating target current phase βtarg based on the current peak value Ip followed by calculating target applied voltage phase αtarg corresponding to the target current phase in a target value setting unit 20, and calculating new applied voltage electrical angle instruction value θvtarg, based on change angle Δθv obtained by correcting a difference between the present applied voltage phase α and the target applied voltage phase αtarg by response time constant L/R of the synchronous motor, rotational speed ω calculated based on the applied voltage and the current, and the previous applied voltage electrical angle instruction value θvtarg, in a voltage electrical angle instruction value setting unit 10.