JP5081633B2 - Motor control device - Google Patents

Description

The present invention relates to an AC motor wiring abnormality that uses a magnetic pole position signal for driving a motor, and more particularly to a motor control device having a plurality of sets of drive windings.

  When servo-controlling a large-capacity motor used in a large press machine with low rotation and high torque, the drive winding on the fixed side consisting of three phases (U, V, W) is connected to a motor rotation shaft (not shown). ) Are controlled side by side. Specifically, as shown in FIG. 2, the torque command (current command) Iref calculated by the speed control circuit unit 21 of the motor control device 20 is distributed to a plurality of current control circuits 22 to 25. A set of windings 27-30 is controlled. An encoder 31 is attached to the rotating shaft of the motor 26, and the phase detection circuit 32 calculates the electrical angle signal θfb. In order to simultaneously control a plurality of windings arranged along the motor rotation axis with the same torque command and electrical angle to produce a high torque, the respective windings 27 to 30 are connected in phase with each other. There is a need.

  Each set winding 27 to 30 is composed of three wires of three phases, and wiring work to the motor control device 20 is performed at the installation site of a large press machine or the like, and rewiring is performed at the use site at the time of maintenance. In order to check each winding, it was necessary to check input / output commands and wiring and review each line, which required a lot of work.

  In addition, if this type of motor of a large industrial machine is connected by incorrect wiring, the command direction and the actually connected phase direction are different and cannot be controlled synchronously, or the phases connected between multiple sets of windings cannot be controlled. If the direction is different, normal operation cannot be performed and the machine may be damaged.

  As a method for automatically detecting miswiring in a servo control system, a method for detecting from a current value and a voltage value during acceleration / deceleration has been proposed (Patent Document 1).

JP-A-9-16233

  Patent Document 1 describes a method of detecting an erroneous connection of a motor output terminal by comparing a current waveform pattern with a detected current at the first acceleration / deceleration after power-on. However, in a large-capacity motor having a plurality of windings, operating in a normal operation mode with an incorrect wiring state may cause unstable operation and runaway depending on the connection state. Further, when a plurality of sets of windings are checked for each set when specifying abnormally connected windings, it takes a lot of time to review and change connections for each set of operations.

  The object of the present invention is to solve these problems by switching to a test mode inside the control device without changing the connection state of a motor having a plurality of sets of windings and operating with a constant test operation command pattern. Accordingly, an object of the present invention is to provide a device capable of preventing a motor runaway and detecting a wiring abnormality.

  The present invention includes a speed control circuit for outputting a current command, a plurality of current control circuits driven by the current command, a motor having a plurality of sets of drive windings connected in correspondence with each current control circuit, In the motor control apparatus, comprising a phase detection circuit for detecting a rotation axis position of the motor as an electrical angle signal, and operating the plurality of sets of drive windings by the current control circuits based on the current command and the electrical angle signal, An erroneous wiring detection device and a drive winding selection unit are provided between the speed control circuit and the current control circuit, and the drive winding selection unit is selected based on an instruction from the erroneous wiring detection device in an erroneous wiring detection mode. A drive current command for detecting miswiring is supplied to a current control circuit corresponding to the drive winding.

  Further, the erroneous wiring detection device has a current level setting circuit and an excitation phase setting circuit, the current level setting circuit outputs a drive current command for erroneous wiring detection, and the excitation phase setting circuit outputs an excitation phase pattern. Then, the motor is excited and the magnetic poles are rotated to drive an arbitrary set of drive windings.

  In addition, when the motor is rotated in the forward or reverse direction based on a current command with a constant current level of the current level setting circuit and a constant excitation frequency of the excitation phase setting circuit, the erroneous wiring detection device has an electrical angle of 1 Position data is fetched from the phase detection circuit every cycle, and the phase forward direction of the wiring is determined from the change in the fetched position data.

  In addition, when the motor is rotated in the forward or reverse direction based on a current command with a constant current level of the current level setting circuit and a constant excitation frequency of the excitation phase setting circuit, the erroneous wiring detection device has an electrical angle of 1 The current detection data of each winding is sequentially taken in every cycle to check the current level, and the disconnection state is determined by comparing the allowable values of the current detection level.

  Further, the erroneous wiring detection device sequentially changes the electrical angle command of the excitation phase setting circuit when the motor is rotated in the normal rotation direction or the reverse rotation direction while the current level of the current level setting circuit is constant. When each phase winding is DC-excited to a current phase in a certain direction, the allowable phase range of the electrical angle data is confirmed, and erroneous wiring of each phase is determined.

  According to the present invention, it is possible to determine an abnormality in a short time by detecting an erroneous wiring in the erroneous wiring detection mode while connecting a plurality of winding wirings.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of the motor control device 1 in which the erroneous wiring detection device 14 and the drive winding selection unit 19 are provided between the speed control circuit and the current control circuit in the motor control device of FIG.

  The erroneous wiring detection device 14 includes a current level setting circuit 15, an excitation phase setting circuit 16, and command selection units 17 and 18, and the command selection units 17 and 18 have contacts a and b, respectively. It consists of a changeover switch. The command selectors 17 and 18 are in the normal operation mode when the contacts 17a and 18b are selected, and are in the miswiring detection mode when the contacts 17b and 18a are selected.

  In the operation control in the normal operation mode, the current control circuits 3 to 6 are driven by the current command Iref calculated by the speed control circuit 2 of the motor control device 1 as in FIG. An encoder 12 for position detection is attached to a motor shaft (not shown) of the motor 7, and the position detection circuit 13 calculates an electrical angle signal θfb. The current control circuits 3 to 6 calculate a voltage command from the current command Iref, the detected values Ifb1 to Ifb4 of the drive currents flowing through the respective drive windings (1) to (4), and the electrical angle signal θfb. The plurality of sets of drive windings (1) to (4) of the motor 7 are driven through a drive circuit (not shown). Each set of drive windings consists of three-phase windings of U, V, and W.

  In the erroneous wiring detection mode, the erroneous wiring detection device 14 selects any of the erroneous wiring functions such as drive winding selection, phase direction determination, disconnection determination, and phase determination from the outside, and the detection target drive winding. A line is selected. Based on the selected function, a predetermined current command pattern Iadj is output from the current level setting circuit 15, and an excitation phase pattern θadj of a predetermined electrical angle is output from the excitation phase setting circuit 16. The current command pattern Iadj is output from the command selection unit 17 as a current command value Iset, and the excitation phase pattern θadj is output from the command selection unit 18 as an electrical angle command θset to the drive winding selection unit 19, respectively.

  For example, when the drive coil selection of the selection function of the erroneous wiring detection device 14 is selected and all of the four sets of drive windings (1) to (4) are selected, the drive winding selection unit 19 has all four sets. As a drive permission winding, the current command value Iset is distributed and output as the current command values Iref1, Iref2, Iref3, and Iref4, and the electrical angle command θset is also distributed and output as θfb1, θfb2, θfb3, and θfb4.

  In addition, when only the first set of windings (1) is not selected (designated to prohibit driving), the driving winding selection unit 19 sends a current command to the current control circuit 3 connected to the winding (1). Iref1 = 0 is sent as an operation stop command, and for the current control circuits 4 to 6 connected to the remaining drive windings (2), (3), (4), the current command value Iadj is set to the current command Iref2, The windings (2), (3), and (4) are driven by sending them as Iref3 and Iref4.

  FIG. 3 shows the drive winding selection state and the waveform of the command value output to each selected winding. The current command value Iadj is output at a constant current level, and the selection of the drive winding is set when the current command value Iadj is zero (the motor is stopped).

  When all windings are selected at timing A, the current command values Iadj correspond to all windings (1) to (4) at the next drive timing, and current command values Iref1, Iref2, Iref3, and Iref4 are respectively Output at a constant level.

  When only the winding (1) is selected at the timing B, the current command Iadj is output at a constant level only to the winding (1) at the next drive timing, and the windings (2), ( 3) and (4) are stopped.

  When the windings (3) and (4) are selected at the timing C, the current commands Iref1 and Iref2 corresponding to the windings (1) and (2) at the next drive timing are zero and the stop commands are used. Current commands Iref3 and Iref4 corresponding to the lines (3) and (4) are output as drive commands at a constant level.

  In addition, when all sets of drive windings are not selected at the timing D, the current commands Iref1, Iref2, Iref3, and Iref4 remain zero even when the current command value Iadj is input at the next drive timing. Then, it becomes a stop state.

  FIG. 4 shows signal waveforms at various parts when the function for determining the phase direction of U, V, and W in the erroneous wiring detection function is selected. A constant current command value Iref is set by the current command value Iadj of the current level setting circuit 15, and a current is output to each winding. When a forward rotation command is received by function selection, an electrical angle command θadj (about 1 Hz) in an increasing direction is output from the excitation phase setting circuit 16 at a constant electrical angle. When the motor rotates slowly and the connection of the motor windings is normal, the current position detected by the encoder 12 is detected in the increasing direction in the order of pos1, pos2, pos3 every electrical angle cycle. When the current position increases due to the forward rotation command, a signal indicating that the phase direction determination is normal is output from the erroneous wiring connection device 14 at the next timing.

  As shown in the right half of FIG. 4, when a reverse rotation command is received in function selection, the electrical angle command θadj is output in a decreasing direction, and the current positions pos1, pos2, pos3 detected from the encoder 12 are in order. Even when the electrical angle is detected in a decreasing direction every cycle, and the current position is decreased by a reverse rotation command, the erroneous wiring connection device 14 outputs a normal determination.

  FIG. 5 shows the signal waveforms of each part when the phase direction determination in the erroneous wiring detection function is performed in a state where the phase order of the windings U, V, and W is reversely connected in the erroneous wiring detection function. Show. The current command Iadj and the electrical angle command θadj are output in the same manner as in FIG. 4. However, since the windings are connected in reverse phase, the actual motor rotation direction is opposite to the command and is detected from the encoder 12. The increase / decrease of the current positions pos1, pos2, pos3 is in the opposite direction to that in the normal state.

  Therefore, when the current position is decreased by the forward rotation command as shown in the left half of FIG. 5 and when the current position is increased by the reverse rotation command as shown in the right half of FIG. The effect of phase direction abnormality determination is output. Since the current command moves slowly according to the current command value having a constant pattern output from the current level setting circuit 15 and the excitation phase setting circuit 16, the runaway of the motor can be prevented even when connected in reverse phase.

  FIG. 6 shows signal waveforms at various parts when the disconnection function is selected in the erroneous wiring detection function. The current command value Iadj and the electrical angle command θadj are output to the drive winding (1) and the winding (2) in the same manner as in the phase direction determination together with the normal rotation and reverse rotation commands. At a certain period, the current detection value Ifb1 of the winding (1) and the current detection value Ifb2 of the winding (2) are alternately confirmed in the incorrect wiring connection device 14, and the error from the current command value is within an allowable range. If it is present, it is determined as normal, and if it is outside the allowable range, it is determined as abnormal.

  In this example, the winding (1) is determined to be normally connected because the current detection value Ifb1 is output at a predetermined level corresponding to the current command Iadj. Since the current detection value Ifb2 is not output at a predetermined level corresponding to the current command Iadj (the current detection value Ifb2 is zero), the winding (2) is determined to be disconnected. Therefore, the normal determination of the winding (1) and the abnormality determination of the winding (2) are alternately output from the miswiring connection device 14.

  4 and FIG. 5 described above is not limited to the synchronous motor because it is only necessary to detect the change of the position information from the encoder 12 and the current detection information of each winding for the disconnection determination of FIG. The present invention can also be applied to a control device using an induction motor.

  FIG. 7 shows signal waveforms at various parts when phase determination is selected in the erroneous wiring detection function in combination with the synchronous motor. In order to start forward rotation, the current command value Iadj is similarly output from the current level setting circuit 15 at a constant level. The excitation phase setting circuit 16 outputs an electrical angle command θadj that repeats moving and stopping every 60 ° electrical angle. When the actuator stops at a certain position, the actual electrical angle signal θfb from the encoder 12 is captured, and an error from θadj output from the excitation phase setting circuit 16 is confirmed in the miswiring connection device 14, and this error is constant. When it is within the allowable range (within the range between the broken lines), a normal determination is output, and when it is outside the allowable range, an abnormality determination is output. This phase determination is repeated every 60 ° until an operation stop command is sent. FIG. 7 shows a case where all the phase determinations are normal.

  FIG. 8 shows the phase relationship between the current phase angle and the winding when combined with a synchronous motor. The current is viewed in the q-axis direction and the phase is viewed in the d-axis direction. When dq axis conversion is used for current control calculation, when excitation is performed in the U-phase rising direction, the phase angle command value is excited in the direction of electrical angle 270 °, and the allowable range for phase determination is centered on 270 °. Judgment is made from a range in which an allowable value is seen in the positive and negative directions. Next, the excitation direction is gradually switched from the direction of the electrical angle 270 °, and compared with the phase information of the encoder when excited in the direction of the electrical angle 330 °, the phase determination in the W-phase falling direction is performed.

  Although the embodiment of FIG. 7 shows the case of a synchronous motor in which the d-axis current is set to 0 and is controlled by the q-axis current command, the d-axis current command and the q-axis current command given to the current control calculation unit are controlled individually Thus, not only a synchronous motor but also an embedded magnet type synchronous motor using a d-axis current and an induction motor can be used to detect miswiring and use an axis selection function with a similar circuit configuration. . 7 and 8, (1) to (6) indicate angular positions, and do not indicate drive windings.

  Further, in the described embodiment, the wiring state is confirmed using a miswiring detection function and a winding selection function for a motor having a plurality of windings as shown in FIG. It is obvious that the present invention can be applied to a combination with a winding motor and also to a driving device in which a plurality of motors are connected.

It is a control circuit block diagram of the Example of this invention. It is a conventional control circuit block diagram. It is explanatory drawing at the time of using drive winding selection. It is explanatory drawing in the case of determining a phase direction. It is explanatory drawing when the phase sequence of a coil | winding is reversely connected. It is explanatory drawing in the case of determining a disconnection. It is explanatory drawing in the case of phase determination. It is a related figure of a phase judgment value and an electric phase angle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Motor control apparatus, 2 ... Speed control circuit 3, 4, 5, 6 ... Current control circuit, 7 ... Motor, (1), (2), (3), (4) ... Winding, 12 ... Encoder DESCRIPTION OF SYMBOLS 13 ... Phase detection circuit 14 ... Error wiring detection apparatus 15 ... Current level setting circuit 16 ... Excitation phase setting circuit 17, 18 ... Command selection part, 19 ... Drive winding (axis) selection part

Claims (5)

A speed control circuit for outputting a current command; a plurality of current control circuits driven by the current command; a motor having a plurality of sets of drive windings connected to each current control circuit; and a rotation shaft of the motor In a motor control device comprising a phase detection circuit for detecting a position as an electrical angle signal, and operating the plurality of sets of drive windings by each current control circuit based on the current command and the electrical angle signal,
An erroneous wiring detection device and a drive winding selection unit are provided between the speed control circuit and the current control circuit, and the drive winding selection unit is selected based on an instruction from the erroneous wiring detection device in an erroneous wiring detection mode. A motor control device that supplies a drive current command for detecting an erroneous wiring to a current control circuit corresponding to a set of drive windings.   The erroneous wiring detection device has a current level setting circuit and an excitation phase setting circuit, the current level setting circuit outputs a drive current command for erroneous wiring detection, and the excitation phase setting circuit outputs an excitation phase pattern. 2. The motor control device according to claim 1, wherein the motor control device can excite a motor and rotate a magnetic pole to drive an arbitrary set of drive windings.   When the motor is rotated in the forward or reverse direction based on a current command with a constant current level of the current level setting circuit and a constant excitation frequency of the excitation phase setting circuit, the erroneous wiring detection device has one electrical angle cycle. 3. The motor control device according to claim 1, wherein position data is fetched from the phase detection circuit every time, and a phase forward direction of the wiring is determined from a change in the taken position data.   When the motor is rotated in the forward or reverse direction based on a current command with a constant current level of the current level setting circuit and a constant excitation frequency of the excitation phase setting circuit, the erroneous wiring detection device has one electrical angle cycle. 4. The motor control device according to claim 1, wherein current detection data of each winding is sequentially fetched for each time to check a current level, and a disconnection state is determined by comparing an allowable value of the current detection level. .   The erroneous wiring detection device sequentially changes the electrical angle command of the excitation phase setting circuit when the motor is rotated in the forward or reverse direction with the current level of the current level setting circuit constant, and the UVW each phase constant direction. 5. When the respective phase windings are DC-excited to the current phase, the phase allowable range of the electrical angle data is confirmed, and erroneous wiring of each phase is determined. 6. Motor control device.

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