摘要:
A voltage type inverter apparatus comprising a voltage correcting portion. The voltage correcting portion corrects a given voltage instruction based on a value generated by passing a direct current bus voltage detected value through a first degree delay filter. In decelerating a speed of the alternating current motor, the speed is decelerated in an overexcited state by multiplying the given voltage instruction by a set gain. Simultaneously, a time constant of the first degree delay filter is made larger than a time constant in a normal control state.
摘要:
It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state. According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.
摘要:
It is the objective of the present invention to provide a sensorless vector control method and a control apparatus, for an alternating-current motor, that can smoothly restart an alternating-current motor in the free running state.According to the present invention, when a current that flows in an alternating-current motor (2) at a restart time 7 the alternating-current motor (2) continuously flows at a designated current level or higher for a designated period of time, it is determined that the rotational direction or the velocity of the alternating-current motor (2) is incorrectly estimated, and a direct current or a direct-current voltage is again applied to again estimate the rotational direction and the velocity.
摘要:
To be able to reduce a speed of an alternating current motor by an inverter apparatus by a time period as short as possible and to control an alternating current motor which is easy to be saturated magnetically by a previously set current or lower such that the inverter apparatus is not stopped by an overcurrent or the alternating current motor is not burned. It is an object of the invention to provide a method and an apparatus capable of reducing a speed of an alternating current motor and capable of shortening a time period of reducing the speed without bringing about a failure by reducing the speed in an overexcited state by making a time constant of a first degree delay filter larger than a time constant in a normal control state, monitoring a current flowing in the alternating current motor and adjusting the time constant in accordance with a current flowing in the alternating current motor in reducing the speed in driving the alternating current motor by a voltage type inverter including a voltage correcting portion for correcting a given voltage instruction by using a value constituted by passing a direct current bus voltage detected value through the first degree delay filter.
摘要:
A servo control apparatus capable of suppressing adverse effects of disturbance, load variation and the like, and realizing robust and high-performance speed control. The apparatus includes both of the following observers: a disturbance observer for adding a disturbance compensation torque Tf, calculated from a torque command T* and an electric motor rotational speed ωm, to a torque command basic signal T0*, calculated on the basis of a deviation between a speed command ω* and a feedback speed ωf by a PI control section, thus outputting the torque command T*; and a phase advance compensation observer for generating, from the torque command basic signal T0* and the electric motor rotational speed ωm, an output of a nominal plant serving as an element in which no delay occurs, thus outputting the output as the feedback speed ωf.
摘要:
There is provided a PWM inverter capable of preventing a phase error from occurring in generating a PWM signal even in the case where a carrier wave frequency is not sufficiently higher than a signal wave frequency. A PWM signal generating section (2) includes a phase adjusting section (11) configured to advance a phase of the signal wave by adding, to a signal wave, a delay component of the PWM signal with respect to the signal wave, the phase delay component being involved by digital control. Furthermore, in a case where the carrier wave frequency is changed, the phase delay component with respect to the signal wave is updated in synchronism with the timing of change of the carrier wave frequency.
摘要:
There is provided a PWM inverter capable of preventing a phase error from occurring in generating a PWM signal even in the case where a carrier wave frequency is not sufficiently higher than a signal wave frequency. A PWM signal generating section (2) includes a phase adjusting section (11) configured to advance a phase of the signal wave by adding, to a signal wave, a delay component of the PWM signal with respect to the signal wave, the phase delay component being involved by digital control. Furthermore, in a case where the carrier wave frequency is changed, the phase delay component with respect to the signal wave is updated in synchronism with the timing of change of the carrier wave frequency.
摘要:
A motor driving apparatus includes a motor driving unit, a low-voltage source, a current detecting element, and an insulation resistance degradation determinator. The motor driving unit includes an inverter coupled between a positive DC bus line and a negative DC bus line of a DC power source. The inverter converts DC power into AC power to drive an AC motor. The low-voltage source is coupled between a ground and at least one of the positive DC bus line and the negative DC bus line. The current detecting element detects a closed circuit current flowing through a closed circuit of the low-voltage source, the AC motor, and a part of the inverter. The insulation resistance degradation determinator makes a comparison between the closed circuit current and a predetermined threshold, and configured to determine, based on the comparison, whether an insulation resistance of the AC motor is degraded.
摘要:
A motor driving apparatus includes a motor driving unit, a low-voltage source, a current detecting element, and an insulation resistance degradation determinator. The motor driving unit includes an inverter coupled between a positive DC bus line and a negative DC bus line of a DC power source. The inverter converts DC power into AC power to drive an AC motor. The low-voltage source is coupled between a ground and at least one of the positive DC bus line and the negative DC bus line. The current detecting element detects a closed circuit current flowing through a closed circuit of the low-voltage source, the AC motor, and a part of the inverter. The insulation resistance degradation determinator makes a comparison between the closed circuit current and a predetermined threshold, and configured to determine, based on the comparison, whether an insulation resistance of the AC motor is degraded.
摘要:
It is an object of the invention to provide a control device for a synchronous motor which can detect the position of a magnetic pole from a zero speed without requiring a signal generator. The invention provides a control device for a synchronous motor which drives the synchronous motor through a voltage-operated PWM inverter and controls a torque and a speed of the motor, including means (6-3) for causing a PWM carrier signal to have an arbitrary phase difference between two phases such as UW, VW or WU in three phases of U, V and W, means (11) for extracting a high frequency voltage and a high frequency current which are thus generated from a detecting voltage or a command voltage and a detecting current, and means (12) for estimating a position of a magnetic flux or a position of a magnetic pole by using the high frequency voltage and the high frequency current which are extracted.