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 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.
摘要:
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.
摘要:
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.
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:
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:
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:
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.