JP2005253300A - Ac motor driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the AC motor driving device constituting a circuit of armature short circuit in an AC motor like a permanent magnet synchronous motor, with its stopping and braking quickly performable at uncontrollable time. <P>SOLUTION: A power converter 30 is provided in its AC output side with a circuit 50 of armature short circuit constituted when control is stopped of the power converter 30. By inserting in series to the circuit 50 of armature short circuit a phase advance capacitor 80 for improving the power factor of an AC motor by phase-advancing a current when an armature short-circuits, the power factor of the AC motor is improved by advancing a current phase when the armature short-circuits by the phase advance capacitor, so as to ensure necessary braking force. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an AC motor drive device.

  Conventionally, if the elevator drive system fails or the elevator loses power due to loss of power, or if a power outage or malfunction occurs and passengers are trapped inside the car, it will be safe to move to the rescue floor Measures are taken to prevent the door from opening easily.

  There are a plurality of methods for preventing the elevator door from being opened in an emergency, depending on the type of electric motor for door opening / closing drive. One of them is a method using an electromagnetic brake. This method can be implemented regardless of the type of electric motor.

  FIG. 5 shows the configuration of the electric motor drive device when the electromagnetic brake is used. This is a configuration in which power is supplied to the power control device 3 from the DC power source 1 via the smoothing capacitor 2, the electric motor 4 is rotationally driven by the DC output of the power control device 3, and the elevator door 6 is driven to open and close. And when controlling the electric power control apparatus 3, the brake control relay 23 is turned on, an electric current is sent through a brake circuit, the electromagnetic brake 21 is opened, and the electric motor 4 can be rotationally driven. Further, when the control of the power control device 3 is stopped or at the time of a power failure, the brake control relay 23 is turned off so that no current flows through the brake circuit, the electromagnetic brake 21 is operated, the motor 4 is stopped, and the opening / closing drive of the elevator door 6 is also stopped Let

  Another method of the electric motor drive device is applied to a door drive device using a permanent magnet DC motor as a driving force, and is a method of obtaining a braking force by short-circuiting the terminals of the permanent magnet DC motor.

  FIG. 6 and FIG. 7 show the configuration of a DC motor driving device when an amateur short circuit is used. This is a configuration in which power is supplied to the power control device 3 from the DC power source 1, the DC output of the power control device 3 is supplied to the electric motor 4 and rotated, and the elevator door 6 is driven to open and close. An amateur short circuit having a B contact relay 5 and a current limiting resistor 7 is provided in parallel with the permanent magnet DC motor 4 on the DC output side. When the power control device 3 is controlled, the B contact relay 5 is turned on (opening operation) to open the armature short circuit, and the output of the power control device 3 is supplied to the permanent magnet DC motor 4 to be driven to rotate. The door 6 is driven to open and close.

  In addition, when the control of the power control device 3 is stopped or during a power failure, the B contact relay 5 is turned off (closed operation), and the terminal of the permanent magnet DC motor 4 is short-circuited via the limiting resistor 7 to generate the power generation braking force. The permanent magnet DC motor 4 is generated and the opening / closing drive of the elevator door 6 is also stopped. In FIG. 7, 11 is an internal reactor of the electric motor 4, 12 is an internal resistance, and 13 is a braking generator.

  However, in the case of a conventional motor drive device having an electromagnetic brake, there are problems in terms of cost, increase in size of the motor, and the like.

  Further, a DC motor driving device that short-circuits a terminal of a permanent magnet DC motor by an amateur short circuit and can perform dynamic braking can be applied to a DC motor but cannot be applied to an AC motor such as a permanent magnet synchronous motor.

  The present invention has been made in view of such conventional problems. An AC short circuit is formed in an AC motor such as a permanent magnet synchronous motor, and an AC motor that can effectively brake the AC motor when it cannot be controlled. An object is to provide an electric motor drive device.

  Also, when an amateur short circuit is configured in an AC motor such as a permanent magnet synchronous motor, unlike a DC motor, the power factor is lowered because the phase control of the motor generated voltage cannot be performed, and the braking force may be reduced. An object of this invention is to provide the alternating current motor drive device which solved the problem.

  An AC motor drive device according to a first aspect of the present invention is a power conversion device that converts DC power of a DC power source into AC power, an AC motor that is rotationally driven by the AC power of the power conversion device, and an AC of the power conversion device. An amateur short circuit that is provided on the output side and shorts the AC motor when the control of the power converter is stopped and generates a braking force, and advances the current phase at the time of the amateur short circuit. Thus, a phase advance capacitor for improving the power factor of the AC motor and ensuring a necessary braking force is inserted in series.

  According to a second aspect of the present invention, in the AC motor drive device according to the first aspect, the amateur short circuit includes a current limiting resistor for limiting a current at the time of the amateur short circuit so that the AC motor is equal to or lower than a maximum rated current. A phase advance capacitor for improving the power factor of the AC motor by advancing the current phase is inserted in series.

  According to the present invention, by providing an amateur short circuit configured when the control of the power converter is stopped on the AC output side of the power converter, the AC motor is short-circuited when the control of the power converter is stopped, and the braking force is increased. It can be generated and stopped. In addition, the power factor is improved by advancing the current phase at the time of the amateur short circuit by the phase advance capacitor, and the necessary braking force can be ensured.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of the first embodiment of the present invention. A DC power is supplied from a DC power source 1 to a power converter 30 such as an inverter through a smoothing capacitor 2, and a U, V, W three-phase AC power converted by the power converter 30 is a permanent magnet synchronous motor that is an AC motor. 40.

  A B contact relay 50 is connected to the AC output side of the power converter 30, and the B contact relay 50 is turned on / off in synchronization with the on / off of the power converter 30. Simultaneously with the turning on, the B contact relay 50 is turned on (opening operation), the AC output of the power converter 30 is supplied to each phase of the permanent magnet synchronous motor 40 which is an AC motor, and at the same time the power converter 30 is turned off, the B contact relay. 50 is turned off (closed operation) to constitute an amateur short circuit. A phase advance capacitor 80 is connected in series with the B contact relay 50 to each phase on the AC output side of the power converter 30.

  Next, the operation of the AC motor driving apparatus having the above configuration will be described with reference to the circuit of FIG. While the power converter 30 is operating, the B-contact relay 50 is in an open state, the AC output of the power converter 30 is supplied to the permanent magnet synchronous motor 40, and the permanent magnet synchronous motor is rotationally driven to move the elevator door 6 Open / close drive.

  At the same time when the power converter 30 is stopped, as shown in the circuit shown in FIG. 2, the B contact relay 50 is turned off (closed operation), the amateur of the permanent magnet synchronous motor 40 is short-circuited, the internal reactor 110, the internal resistance 120, and braking. An amateur short circuit in which the generator 130 is connected in series is configured. At this time, the permanent magnet synchronous motor 40 becomes the braking generator 130, converts the energy into the generated voltage of the braking generator 130, and this voltage is consumed by the internal reactor 110, the internal resistance 120, and the phase advance capacitor 80, and the permanent magnet The synchronous motor 4 can be braked and thus the elevator door 6 can be braked. In the case of the present embodiment, the phase advance capacitor 80 controls the phase relationship between the voltage generated in the armature short circuit during braking and the flowing current, thereby improving the power factor and increasing the braking force, thereby making the motor 40 safer. Can be stopped.

  Next, an AC motor driving apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The feature of the second embodiment is that, with respect to the first embodiment shown in FIG. 1, a limiting resistor 70 and a phase advance capacitor are connected in series with the B contact relay 50 in each phase of the AC output of the power converter 30. 80 is connected. Other configurations are the same as those in the first embodiment shown in FIG.

  In the case of the AC motor driving device of the second embodiment, an amateur short circuit as shown in FIG. 4 is configured when the power converter 30 is stopped. At this time, the permanent magnet synchronous motor 40 becomes the braking generator 130, converts energy into the generated voltage of the braking generator 130, and this voltage is consumed by the internal reactor 110, the internal resistance 120, the limiting resistance 70, and the phase advance capacitor 80. Then, the permanent magnet synchronous motor 40 can be braked, and thus the elevator door 6 can be braked. In the case of the second embodiment, the limiting resistor 70 prevents the current flowing in the amateur short circuit during braking from exceeding the maximum rated current of the permanent magnet synchronous motor 40, and at the same time, the phase advance capacitor 80 forms the amateur short circuit. By controlling the phase relationship between the generated voltage and the flowing current, the power factor can be improved to increase the braking force, and even when the weight of the door panel of the elevator door 6 increases, it can be safely stopped.

1 is a circuit diagram of a first embodiment of the present invention. The circuit diagram which shows the structure at the time of the amateur short circuit by said embodiment. The circuit diagram of the 2nd Embodiment of this invention. The circuit diagram which shows the structure at the time of the amateur short circuit by said embodiment. The circuit diagram of the elevator door drive device using the conventional electromagnetic brake. The circuit diagram of the elevator door drive device which employ | adopted the conventional permanent magnet direct current motor. The circuit diagram which shows the structure at the time of the amateur short circuit by said conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC power supply 6 Elevator door 30 Power converter 40 Permanent magnet synchronous motor 50 B contact relay 70 Limit resistance 80 Phase advance capacitor 110 Internal reactor 120 Internal resistance 130 Braking generator

Claims (2)

A power conversion device that converts DC power of a DC power source into AC power;
An AC motor that is rotationally driven by the AC power of the power converter;
An AC short circuit provided on the AC output side of the power converter, causing the AC motor to short-circuit when control of the power converter is stopped, and generating a braking force;
The armature short circuit has a phase advance capacitor inserted in series to improve the power factor of the AC motor by advancing the current phase at the time of the armature short circuit and to secure a necessary braking force. AC motor drive device.   The current short circuit is characterized in that a current limiting resistor for limiting the current at the time of the amateur short circuit to make the AC motor below a maximum rated current is inserted in series with the phase advance capacitor. 2. The AC motor drive device according to 1.

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