JP2017229141A - Speed control board and manufacturing method for speed control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed control board that while using a power control board configured to perform drive/stop control on a star-delta switchable three-phase induction motor, enables speed control on the three-phase induction motor.SOLUTION: A speed control board comprises an inverter that on the basis of power supplied from a power control board, drives a star-delta switchable three-phase induction motor. The inverter includes a wire connection switching unit for switching a wire connection state of a three-phase AC circuit so that the three-phase induction motor is started by star-delta start control, the wire connection switching unit being provided on the input side. The inverter controls rotation speed of the three-phase induction motor on the basis of power supplied through the wire connection switching unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a speed control panel for a three-phase induction motor and a method for manufacturing a speed control system.

  A technique for starting a three-phase induction motor by a star delta (Y-Δ) starting method is known (see Patent Document 1). The electric motor 3 shown in FIG. 9 is an example of a three-phase induction motor including windings 3a, 3b, and 3c (stator windings) that can be switched by star delta (Y-Δ). The current at the start of the three-phase induction motor (starting current) may reach several times that in steady operation depending on the control method.

For example, the power control panel 1 that controls the electric motor 3 may be configured as shown in FIG. The power control panel 1 starts the electric motor 3 by the Y-Δ starting method, and does not include an inverter for controlling the electric motor 3 in its configuration. For example, in the power control panel 1, the connection state of the windings 3 a, 3 b, 3 c of the electric motor 3 is switched by the connection switching unit 10 as follows. When the electric motor 3 is started, the power control panel 1 opens the electromagnetic switch 11 (off state) and closes the electromagnetic switch 12 (on state), so that the windings 3a, 3b, 3c are in the Y-connection state. The voltage applied to each winding is 1 / √3, and the starting current is suppressed to 1/3. Thereafter, the power control panel 1 turns on the electromagnetic switch 11 during steady operation of the electric motor 3 and turns off the electromagnetic switch 12 so that the windings 3a, 3b, and 3c are applied to the respective windings in a Δ connection state. Voltage is increased, and the electric motor 3 is operated at full voltage. The power control panel 1 controls the electric power supplied to the electric motor 3 using the electromagnetic switch 11 and the electromagnetic switch 12, thereby limiting an excessive current at the time of starting. The power control panel 1 can drive the electric motor 3 by an ON / OFF control method for switching between a driving state and a stopped state, but cannot perform speed control.
In addition, when configured by the ON / OFF control method, energy may be consumed in comparison with a configuration in which the three-phase induction motor is started by the inverter control method and speed control is possible.

JP 58-21380 A

  However, in a facility equipped with an ON / OFF control type power control panel and a Y-Δ switchable three-phase induction motor, changing the control method for the three-phase induction motor from ON / OFF control to an inverter control method is not possible. It ’s not easy. For example, in order to change the power control panel to an inverter control type in order to make the above change, it is necessary to remove and newly install the power control panel. Further, in order to remodel the power control panel to the inverter control system, it is necessary to modify the main circuit in the power control panel to add a new function. As described above, neither method is easy. In addition to this, it may be accompanied by a replacement work of a cable connecting the power control panel to the three-phase induction motor.

  The present invention has been made in consideration of the above circumstances, and the speed of the three-phase induction motor is utilized while utilizing a power control panel configured to control the driving stop of the three-phase induction motor capable of star-delta switching. It is an object of the present invention to provide a speed control panel that enables control and a method of manufacturing a speed control system.

  In order to solve the above-described problem, an embodiment of the present invention includes an inverter that drives a star-delta (Y-Δ) switchable three-phase induction motor based on electric power supplied from a power control panel, and the inverter Based on the electric power supplied through the connection switching unit, a connection switching unit is provided on the input side to switch the connection state of the three-phase AC circuit so that the three-phase induction motor is started by Y-Δ start control. A speed control panel for controlling the rotational speed of the three-phase induction motor.

  In addition, the speed control panel of the one embodiment includes a control unit that detects that the state of the connection switching unit is in a Δ connection state.

  Further, the connection switching unit according to the speed control panel of the one embodiment is included in a power control panel that enables the three-phase induction motor to be started by Y-Δ start control, and the inverter includes: The power control panel is housed in a housing provided outside the housing.

  The speed control panel according to the above-described embodiment includes a drive mode switching unit that switches a power supply path for the three-phase induction motor to either a power supply path from the inverter or a power supply path from the power control panel.

  In addition, the drive mode switching unit in the speed control panel of the one embodiment supplies power from the power control panel to the three-phase induction motor when the inverter cannot supply power to the three-phase induction motor. The power supply path for the three-phase induction motor is switched so as to be supplied.

  In addition, the speed control panel according to the embodiment includes an input-side power supply path switching unit that switches a power supply path between the connection switching unit and the inverter so as to correspond to the state of the connection switching unit.

  Further, the speed control panel of the one embodiment includes a first terminal unit to which power is supplied from a power control panel including the connection switching unit, and a second terminal unit to which power is supplied from the power control panel. One of the first terminal portion and the second terminal portion is a three-phase alternating current terminal included in the terminal portion when the connection switching portion is in a Y-connection state. Are connected to each other.

  The speed control system manufacturing method according to one embodiment of the present invention is supplied via a power control panel including a connection switching unit for starting a three-phase induction motor by Y-Δ start control, and the connection switching unit. A step of electrically connecting a speed control panel for converting the power to be converted and adjusting the speed of the three-phase induction motor by the converted power; and electrically connecting the three-phase induction motor to the output side of the speed control panel Connecting to.

  The present invention provides a speed control panel that enables speed control of a three-phase induction motor and a method for manufacturing the speed control system, while using a power control panel configured to stop and drive the three-phase induction motor. can do.

It is a block diagram which shows the speed control system of the electric motor of this embodiment. It is a figure for demonstrating the structure of a comparative example. 3 is a front view of a speed control panel 2. FIG. 3 is an external view showing a configuration example of a speed control panel 2. FIG. It is a figure for demonstrating the procedure until it connects the speed control board 2 to the electric motor 3. FIG. It is a figure for demonstrating the procedure until speed control of the electric motor. 3 is a timing chart when the speed of the electric motor 3 is controlled. 6 is a timing chart when the electric motor 3 is ON / OFF controlled. 2 is a configuration diagram of an electric motor 3. FIG. It is an enlarged view of the part which has arrange | positioned the electromagnetic switch in a modification. It is a block diagram which shows the speed control system of the electric motor of 2nd Embodiment. It is a block diagram which shows the speed control system of the electric motor of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing an electric motor speed control system including a speed control panel.
A speed control system 5 shown in FIG. 1 includes a power control panel 1, a speed control panel 2, and an electric motor 3. The central controller 8 manages the control state of the speed control system 5. The central controller 8 collects control states from devices such as the power control panel 1 and the speed control panel 2 and controls the motor 3 with respect to the power control panel 1 and the speed control panel 2. Command.

  The electric motor 3 is a three-phase induction motor capable of star-delta (Y-Δ) switching of the windings 3a, 3b, 3c (stator winding) as shown in FIG. For example, the symbol P indicates a compressor, pump, or fan that is a load driven by the axial force of the electric motor 3. For example, the compressor P may constitute a part of a refrigerator (air conditioner). Although not shown, the compressor P may be connected to a conduit for circulating the heat medium, and the conduit may be provided with a heat exchanger, an expansion valve, and the like. The electric motor 3 circulates the heat medium by operating the compressor P.

  The power control panel 1 includes a connection switching unit 10, a control logic unit 15, and an MCCB 16. Three-phase AC power is supplied from the power source PS to the TB 110 of the power control panel 1.

  The connection switching unit 10 includes an electromagnetic switch 11, an electromagnetic switch 12, and a Y circuit 13. The connection switching unit 10 switches the state of the electromagnetic switch 11 and the electromagnetic switch 12 to change the stator winding specification of the motor 3 to star connection (Y connection) or delta connection (Δ connection). When the “electromagnetic switch 11 is in an off state and the electromagnetic switch 12 is in an on state”, the electric motor 3 is connected to the Y circuit 13 by the electromagnetic switch 12 to form a Y connection. The Y circuit 13 connects the phases to each other to make a midpoint. Conversely, when the “electromagnetic switch 11 is in the on state and the electromagnetic switch 12 is in the off state”, the electric motor 3 is connected to the power source by the electromagnetic switch 11 to form a Δ connection.

  The control logic unit 15 sends a switching signal for switching to Y connection or Δ connection to the connection switching unit 10 to switch the states of the electromagnetic switch 11 and the electromagnetic switch 12. The control logic unit 15 outputs the control state to the central control device 8 and receives a control command related to driving of the electric motor 3 from the central control device 8. The MCCB 16 cuts off the electric power supplied from the power control panel 1. The control logic unit 15 may be configured by a combination of control relays, or a processor such as a DSP (digital signal processor) or CPU (Central Processing Unit) that can be controlled by executing a program, an I / O An (Input / Output) port, an A / D (Analog / Digital) converter, and the like may be included.

  Here, with reference to FIG. 2, the description at the time of applying the power control panel 1 and the electric motor 3 is supplemented about the comparative example relevant to embodiment. FIG. 2 is a diagram for explaining the configuration of the comparative example. As shown in FIG. 2, the power control panel 1 and the electric motor 3 are connected to each other by a cable, so that the power control panel 1 can drive the electric motor 3. At that time, the power control panel 1 can control the operation of the electric motor 3 by starting the electric motor 3 by the Y-Δ starting method.

A configuration example of the speed control panel 2 will be described. FIG. 3 is a front view of the speed control panel 2.
The speed control panel 2 includes a door DR and a housing body BD that instructs the door DR. The housing body BD houses various components such as the inverter 20, the electromagnetic switch 21, the electromagnetic switch 22, the electromagnetic switch 23, the electromagnetic switch 24, the electromagnetic switch 25, the electromagnetic switch 26, and the control unit 29. . For example, the housing body BD is fastened with screws to a channel base provided at the bottom thereof, and is installed in a self-supporting state. Furthermore, the upper part of the housing body BD or the like may be supported by an upper support or the like. Alternatively, the back surface of the housing body BD may be arranged along the wall surface or the like, and the back surface of the housing body BD may be fastened to the anchor bolt provided on the wall surface with a nut or the like. The door DR is provided with a display part DISP indicating the control state of the speed control panel 2 and a ventilation port VE, an exhaust port EP and the like so as to cool the speed control panel 2. A cooling fan (not shown) may be provided on the back side of the door DR at the position of the exhaust port EP of the door DR.

FIG. 4 is an external view showing a configuration example of the speed control panel 2. The speed control panel 2 shown in FIG. 4 is a front view of the door DR opened.
An attachment member F is provided near the back surface in the housing body BD. In addition to the terminal portion, the attachment member F is provided with an inverter 20, MCCB 27, MCCB 28, operation unit OP, reactor L, electromagnetic switch 21 to electromagnetic switch 26, control unit 29, and the like. From the top to the bottom of the mounting member F, the inverter 20, the MCCB 27, the MCCB 28, the operation unit OP, the reactor L, the electromagnetic switch 21 to the electromagnetic switch 26, the control unit 29, and the like are arranged. Yes. The attachment member F is provided with terminal portions collectively, and the position thereof is determined in accordance with the cable inlet to the housing body BD.
The terminal portion includes TB211, TB212, TB213, TB214, TB221, TB222 and the like which will be described later. The position of each part shown in the drawing is an example when a cable is drawn from the bottom of the housing body BD. The position where each part shown in the figure is arranged shows an example, and is not limited to this.

  The speed control panel 2 includes an inverter 20, an electromagnetic switch 21, an electromagnetic switch 22, an electromagnetic switch 24, an electromagnetic switch 25, an electromagnetic switch 26, an MCCB 27, an MCCB 28, and a control unit 29. MCCB 27 and MCCB 28 cut off the electric power supplied to the speed control panel 2 via the power control panel 1.

  Each of the electromagnetic switch 21 to the electromagnetic switch 26 is an electrically controllable contactor (switch), and has three contacts for three-phase alternating current and auxiliary contacts linked to these contacts.

  Inverter 20 includes a conversion unit 201 and a control unit 202.

The conversion unit 201 receives the control signal from the control unit 202 and adjusts the power supplied to the motor 3 based on the power supplied from the power control panel 1. For example, the conversion unit 201 includes a forward conversion circuit 2011, a smoothing circuit 2012, and an inverse conversion circuit 2013. The forward conversion circuit 2011 rectifies alternating current and converts it to direct current. The smoothing circuit 2012 smoothes the direct current output from the forward conversion circuit 2011. The inverse conversion circuit 2013 generates and outputs an alternating current with a frequency determined by the control from the control unit 202 from the smoothed direct current.
The control unit 202 receives control from the control unit 29, receives a speed control signal from the central control device 8, generates a drive signal for the inverse conversion circuit 2013 based on them, and controls the inverse conversion circuit 2013. The value indicated by the speed control signal may be a continuous value or a discrete value. The speed control signal may be based on, for example, a so-called 4-20 mA signal. The control unit 202 includes an I / O port and an A / D converter, and may be configured by a DSP, a CPU, or the like that can be controlled by executing a program.

  The control unit 29 receives the connection state signal from the power control panel 1 and controls the inverter 20 based on the connection state signal. The control unit 29 may include an I / O port, an A / D converter, and a DSP or CPU that can be controlled by executing a program.

(About electrical connection)
The electrical connection configuration of the speed control panel 2 will be described with reference to FIG. FIG. 1 is a single line connection diagram.
The speed control panel 2 is connected to the next external device. The cable CBL1 from the power control panel 1 is connected to the TB 211, the cable CBL2 from the power control panel 1 is connected to the TB 212, and the cable CBL3 from the power control panel 1 is connected to the TB 213. The UVW pole side of the motor 3 is connected to the TB 221, and the XYZ pole side of the motor 3 is connected to the TB 222. A cable CBL4 from the central control device 8 is connected to the TB 214.

  Each of TB211, TB212, TB221, and TB222 is a terminal for connecting a three-phase AC cable. Each of TB 213 and TB 214 is a control signal terminal. LN11 to LN14, LN21 to LN24, and LN31 to LN35 indicate conductors such as cables.

The primary side of the MCCB 27 is connected to the TB 211 via the LN 11. The primary side of the electromagnetic switch 21 is connected to the secondary side of the MCCB 27 via the LN 12, the primary side of the electromagnetic switch 26 is connected via the LN 31, and the input terminal of the inverter 20 is connected via the LN 33.
The primary side of the electromagnetic switch 25 and the primary side of the electromagnetic switch 24 are connected to the input terminal of the inverter 20 via the LN 34 and the LN 35. Although not shown, the reactor L is connected to the inverter 20.
The secondary side of the electromagnetic switch 21 is connected to the secondary side of the electromagnetic switch 24 via the LN 13 and further to the TB 221 via the LN 14.

  The primary side of the MCCB 28 is connected to the TB 212 via the LN 21. The secondary side of the MCCB 28 is connected to the primary side of the electromagnetic switch 22 via the LN 22 and the secondary side of the electromagnetic switch 26 via the LN 32. The secondary side of the electromagnetic switch 22 is connected to the secondary side of the electromagnetic switch 25 via the LN 23 and further to the TB 222 via the LN 24.

The paths of LN31, LN32, LN33, and LN34 and the paths of LN35, LN14, and LN24 are used when the inverter 20 functions, and the power supplied from the power control panel 1 is supplied to the inverter 20. Are converted and supplied to the electric motor 3.
On the other hand, the paths of LN12, LN13, LN14, and LN15 described above are paths used when the inverter 20 cannot function, and the inverter 20 converts the power supplied by the power control panel 1. Without being supplied to the electric motor 3.

(Procedure until the speed control panel 2 is connected to the motor 3)
The procedure from the configuration shown in FIG. 2 to the configuration shown in FIG. 1 until the speed control panel 2 is connected to the motor 3 will be described. FIG. 5 is a diagram for explaining a procedure until the speed control panel 2 is connected to the electric motor 3.

  First, the electrical connection between the power control panel 1 and the electric motor 3 is released (S11), and the power control panel 1 and the speed control panel 2 are connected by the cable CBL1, the cable CBL2, and the cable CBL3 (S12). The speed control panel 2 and the central controller 8 are connected by the cable CBL4 (S13). The cables from the electric motor 3 are connected to the terminals 221 and 222, which are the output terminals of the speed control panel 2, respectively (S14).

  As described above, the speed control panel 2 can be connected to the electric motor 3. For the cable CBL1 and cable CBL2 that connect the power control panel 1 and the speed control panel 2 or the cable that connects the speed control panel 2 and the motor 3, connect the power control panel 1 and the motor 3. The cable that has been used may be used.

(Procedure until speed control of the motor 3)
A procedure until speed control of the electric motor 3 will be described. FIG. 6 is a diagram for explaining a procedure until the speed of the electric motor 3 is controlled.

  First, the power control panel 1 and the speed control panel 2 are electrically connected (S21). For example, the power control panel 1 enables the connection switching unit 10 to supply power according to a procedure based on Y-Δ start control (S21A). The speed control panel 2 converts the power supplied from the power control panel 1 via the connection switching unit 10 by the inverter 20 (S21B).

The speed control panel 2 turns on the electromagnetic switch 24 and the electromagnetic switch 25 based on the connection state signal indicating the connection state of the power control panel 1 and electrically connects the motor 3 to the output side of the speed control panel 2. (S22). The speed control panel 2 adjusts the speed of the electric motor 3 with the converted electric power (S23).
The speed of the electric motor 3 is controlled by the above procedure.

(Operation of the speed control panel when the speed of the motor 3 is controlled)
The operation when the speed of the motor 3 is controlled by the speed control panel 2 in accordance with the above procedure will be described.
FIG. 7 is a timing chart when the speed of the electric motor 3 is controlled. (A) to (i) shown in FIG. 7 respectively indicate the following signal states. (A) shows the driving | operation command issued from the central control apparatus 8. FIG. (B) and (c) show the electric power output from the power control panel 1 and the connection state signal. (D) to (f) show the state of the electromagnetic switch in the speed control panel 2. (G) and (h) show the control state of the inverter 20 and the result of self-diagnosis. (I) shows the rotation state of the electric motor 3.

(State of standstill)
At t0, the control logic unit 15 is in a state where the electric motor 3 is stopped. That is, the control logic unit 15 causes the connection switching unit 10 to cut off the supply of power from the power control panel 1. In addition, the control logic unit 15 outputs, based on the connection state signal, that the connection state in the power control panel 1 is not Δ connection. In addition, a connection state signal will be in the same state as the case where it is in the state which does not supply electric power, also when the connection state in the power control panel 1 mentioned later is a Y connection.
The control unit 29 of the speed control panel 2 detects from the connection state signal that the connection state in the power control panel 1 is the Y connection state or that the power control panel 1 is in a state of not supplying power. In response to this, the control unit 29 turns off all the electromagnetic switches 26 from the electromagnetic switch 21 and controls the inverter 20 to stop the conversion operation.

(Stop and start from low-speed rotation)
At t <b> 1, the control logic unit 15 receives a command for starting the electric motor 3 from the central control device 8. The control logic unit 15 detects the above command and switches the connection switching unit 10 to change the connection in the power control panel 1 to the Y connection. The power control panel 1 is in a state where power can be supplied. Although the connection state in the power control panel 1 changes to the Y connection, the control logic unit 15 does not change the state of the connection state signal.

The control unit 29 of the speed control panel 2 is controlled by the connection state signal. However, since the state of the signal does not change from the state where the power control panel 1 does not supply power, the control state is not changed. That is, the control unit 29 detects that the connection state in the power control panel 1 is a Y-connection state, or that the power control panel 1 is in a state of not supplying power. The control unit 29 turns off all of the electromagnetic switches 21 to 26 and maintains a control state for stopping the conversion operation for the inverter 20.
As described above, until this stage, the speed control panel 2 does not output electric power for driving the electric motor 3. The electric motor 3 is maintained in a state where no electric power is supplied.

(The stage when a predetermined time has elapsed from the command for starting the electric motor 3)
When a predetermined time elapses from t1 and reaches t2, the control logic unit 15 switches the connection switching unit 10 to change the connection in the power control panel 1 to Δ connection. For example, the predetermined time (t2-t1) is based on the time taken for the rotation speed of the motor 3 to reach a predetermined rotation speed on the assumption that the motor 3 is started by the Y-Δ start control. Has been determined. The power control panel 1 is in a state capable of supplying electric power for driving the electric motor 3 by Δ connection. In addition, the control logic unit 15 outputs that the connection state in the power control panel 1 is in the Δ connection by the connection state signal. Until the control logic unit 15 switches the connection switching unit 10 as described above, the electric motor 3 remains in a stopped state. The actual rotational speed of the electric motor 3 at the timing when the rotational speed of the electric motor 3 reaches a predetermined rotational speed is different from the transfer rate estimated above.

  The control unit 29 of the speed control panel 2 receives the connection state signal and detects that the connection state in the power control panel 1 is Δ connection. In response to this, the control unit 29 turns on the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 26. The control unit 29 keeps the electromagnetic switch 21 and the electromagnetic switch 22 in the off state. The control unit 29 controls the inverter 20 to start the conversion operation by the conversion unit 201. Inverter 20 receives a control command to start the conversion operation by conversion unit 201. Further, the inverter 20 adjusts the rotation speed of the electric motor 3. For example, the inverter 20 receives the control from the central control device 8 and controls the electric motor 3 so that the instructed rotational speed is obtained. As a result, the electric motor 3 is driven by the above control so that the rotation speed gradually increases.

(Operation of speed control panel when motor 3 is not speed controlled)
Next, the case where the speed control panel 2 is simply driven by ON / OFF control without performing the speed control of the electric motor 3 will be described.

The following cases can be cited as cases where the motor 3 is driven without speed control, that is, when the motor 3 is ON / OFF controlled without functioning the speed adjustment function by the inverter 20.
(1) When the inverter 20 detects a state (abnormal state) where a normal output cannot be obtained with the self-diagnosis function.
(2) When the speed adjusting device is instructed to stop the output of the inverter 20 from an external device or the like.
(3) The inverter 20 cannot be used due to failure, maintenance, inspection, etc. of the inverter 20.

  In the above case, since the output of the inverter 20 cannot be used, for example, the electric motor 3 can be driven without using the output of the inverter 20 by the following method. In the following description, the case (1) will be described as an example. Similarly, in the cases (2) and (3), the electric motor 3 can be driven without using the output of the inverter 20.

  FIG. 8 is a timing chart when the electric motor 3 is ON / OFF controlled without speed control.

  The inverter 20 has a self-diagnosis function. At t <b> 10, the control unit 202 detects a function stop state in which power cannot be supplied from the conversion unit 201, and outputs the information to the control unit 29.

  The control unit 29 of the speed control panel 2 receives a signal indicating the function stop state of the inverter 20 and detects that the inverter 20 is in the function stop state. In response to this, the control unit 29 turns off the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 26. The control unit 29 turns on the electromagnetic switch 21 and the electromagnetic switch 22. Note that the control logic unit 15 may permit the drive of the electric motor 3 after the electromagnetic switch 21 is changed to the above state from the electromagnetic switch 21.

(Stop and start from low-speed rotation)
At t <b> 11, the control logic unit 15 receives a command for starting the electric motor 3 from the central control device 8. The control logic unit 15 detects the above command and switches the connection switching unit 10 to change the connection in the power control panel 1 to the Y connection. The power control panel 1 is in a state where power can be supplied.

  In addition, the control logic unit 15 may output that the connection state in the power control panel 1 is the Y connection by a connection state signal. Even if the signal is output, the control unit 29 does not perform control corresponding to the signal.

  In the speed control panel 2, the electromagnetic switch 21 and the electromagnetic switch 22 are turned on, and the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 26 are turned off. The speed control board 2 relays the electric power supplied from the power control board 1 and supplies it to the electric motor 3. The electric motor 3 is started with its connection being a Y connection.

(The stage when a predetermined time has elapsed from the command for starting the electric motor 3)
At t12, the control logic unit 15 switches the connection switching unit 10 in accordance with the timing when the rotation speed of the electric motor 3 reaches a predetermined rotation speed, so that the connection in the power control panel 1 is Δ connection. The power control panel 1 supplies electric power to the electric motor 3 through the speed control panel 2 with the electric motor 3 in a Δ connection. The rotation speed of the electric motor 3 is adjusted to the transfer rate by the Y-Δ starting method. That is, the electric motor 3 is started by Y-Δ start control by the power control panel 1.

  According to the embodiment, the inverter 20 that drives the electric motor 3 that can be switched between Y and Δ based on the electric power supplied from the power control panel 1 is provided. The inverter 20 is provided with a connection switching unit 10 on the input side for switching the connection state of the three-phase AC circuit so that the electric motor 3 is started by Y-Δ start control. The inverter 20 controls the rotational speed of the electric motor 3 based on the electric power supplied through the connection switching unit 10 and uses a power control panel configured to control the driving stop of the three-phase induction motor. Enables speed control of three-phase induction motors.

  Further, the control unit 29 detects that the state of the connection switching unit 10 is in the state of Δ connection, so that the control on the speed control panel 2 side is interlocked with the control state on the power control panel 1 side. It becomes possible to control the state. Thereby, the speed control panel 2 can drive the electric motor 3 when the power control panel 1 is in a Δ connection state.

Moreover, the power control panel 1 enables the electric motor to be started by Y-Δ start control.
The connection switching unit 10 is included in the power control panel 1 as described above. The inverter 20 may be housed in a housing provided outside the housing of the power control panel 1. According to this, it can comprise so that the connection switching part 10 and the inverter 20 may be accommodated in another housing | casing.

  Further, the speed control panel 2 of the present embodiment may switch the power supply path for the electric motor 3 to either the power supply path from the inverter 20 or the power supply path from the power control panel 1. Furthermore, the speed control panel 2 can switch the power supply path to the electric motor 3 so that the electric power is supplied from the power control panel 1 to the electric motor 3 when the inverter 20 cannot supply electric power to the electric motor 3. Become. Thereby, the speed control panel 2 can drive the electric motor 3 using the power supply path from the power control panel 1 even when the inverter 20 cannot function. The electromagnetic switch 21, the electromagnetic switch 22, the electromagnetic switch 24, and the electromagnetic switch 25 are an example of a drive mode switching unit.

  Further, when the speed control panel 2 of the present embodiment causes the inverter 20 to function by switching the power feeding path between the connection switching unit 10 and the inverter 20 so as to correspond to the state of the connection switching unit 10. The power when the connection switching unit 10 is in the Δ connection state can be used. When the motor 3 is driven without the inverter 20 functioning, the motor 3 is started by Y-Δ start control. It becomes possible to make it. The electromagnetic switch 26 is an example of an input side power supply path switching unit.

  In addition, the speed control panel 2 of the present embodiment includes a first terminal unit to which power is supplied from the power control panel 1 including the connection switching unit 10 and a second terminal unit to which power is similarly supplied from the power control panel 1. And comprising.

When one of the first terminal portion and the second terminal portion is in the Y-connection state, the three-phase AC terminals included in the terminal portion are connected to each other. You may make it do. TB211 and TB212 are examples of the first terminal portion and the second terminal portion.
Thus, by providing the first terminal portion and the second terminal portion separately, each can be connected to the power control panel 1, and Y−Δ by the connection switching unit 10 in the power control panel 1. It becomes possible to use electric power generated by starting.

(Modification of the first embodiment)
A modification of the first embodiment will be described. FIG. 10 is an enlarged view of a portion where the electromagnetic switch is arranged. Each of the electromagnetic switch 21, the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 22 is arranged in the horizontal direction in order. For example, as shown in the drawing, the electromagnetic switch 21, the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 22 are arranged in this order from left to right. In addition, you may arrange | position the electromagnetic switch 26 on the outer side of the arrangement | sequence along said arrangement | sequence.

  That is, the electromagnetic switch 24 and the electromagnetic switch 25 connected to the output of the inverter 20 are arranged on the center side of the row in which the above four electromagnetic switches are arranged. The electromagnetic switch 21 and the electromagnetic switch 22 for cutting off the electric power supplied from the power control panel 1 to the electric motor 3 are respectively arranged outside the electromagnetic switch 24 and the electromagnetic switch 25 arranged on the center side of the row.

For example, the LN 13 that connects the electromagnetic switch 21 and the electromagnetic switch 24 and the LN 23 that connects the electromagnetic switch 25 and the electromagnetic switch 22 connect the electromagnetic switch 24 and the electromagnetic switch 25 below each electromagnetic switch. The LN 35 is provided on the upper side of each electromagnetic switch. By arranging the intervals of the electromagnetic switch 21, the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 22 to be equal to each other, the LN13, LN23, and LN35 are replaced with a cable connection, and a plate-shaped or bar-shaped conductor is used. be able to. The plate-like or bar-like conductors may be formed so that the portions other than the end portions are not in contact with each other, or each is covered with a resin or the like.
Note that the order of arranging the four electromagnetic switches arranged in the horizontal direction as exemplified above may be reversed left and right. Among the four electromagnetic switches, the left and right positions of the electromagnetic switch 24 and the electromagnetic switch 25 may be interchanged.
The LN 13 that connects the electromagnetic switch 21 and the electromagnetic switch 24 and the LN 23 that connects the electromagnetic switch 25 and the electromagnetic switch 22 are LN 35 that connects the electromagnetic switch 24 and the electromagnetic switch 25 above each electromagnetic switch. May be provided below each electromagnetic switch.

  According to this modification, it is possible to obtain the same effect as the above embodiment. In addition to this, electrical connection among the electromagnetic switch 21, the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 22 in the speed control panel 2 can be easily performed. Furthermore, the pitch at which the electromagnetic switch 21, the electromagnetic switch 24, the electromagnetic switch 25, and the electromagnetic switch 22 are arranged can be shortened, and the housing of the speed control panel 2 can be downsized. Thus, it is possible to arrange a speed control panel that enables speed control of the three-phase induction motor while utilizing a power control panel configured to stop and drive the Y-Δ switchable three-phase induction motor. It becomes easy.

(Second Embodiment)
A second embodiment will be described. The inverter 20 does not continuously output the detection signal of the abnormal state of the inverter 20 detected by the self-diagnosis function. Therefore, the control unit 29 of the first embodiment is configured to hold a detection history of the abnormal state of the inverter 20 detected by the self-diagnosis function of the inverter 20. Instead, this embodiment controls the inverter 20 so as to continuously output the detection signal of the abnormal state.

  FIG. 11 is a configuration diagram showing a motor speed control system including the speed control panel of the present embodiment. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and differences from the configuration shown in FIG. 1 will be mainly described.

  The speed control panel 2 includes an inverter 20, an electromagnetic switch 21, an electromagnetic switch 22, an electromagnetic switch 24, an electromagnetic switch 25, an electromagnetic switch 26, an electromagnetic switch 26B, an MCCB 27, an MCCB 28, and a control unit 29. Is provided. The speed control panel 2 is different from the first embodiment in that an electromagnetic switch 26B is added.

  The inverter 20 of the present embodiment further has the following configuration. The inverter 20 continues to be supplied with control power to the inverter 20 and continues the contact signal indicating the occurrence of an abnormal state of the inverter 20 if the conversion power supplied to the input of the inverter 20 does not recover. And output.

  The electromagnetic switch 26B is an electrically controllable contactor (switch) similar to the electromagnetic switch 21 to the electromagnetic switch 26 described above, and has three contacts for three-phase alternating current and auxiliary that is linked to these contacts. Has contacts. The state of the electromagnetic switch 26B is switched in the same manner as the electromagnetic switch 26 under the control of the control unit 29 or the like.

  The secondary side of the MCCB 27 is connected to the primary side of the electromagnetic switch 21 via the LN 12, the primary side of the electromagnetic switch 26 B via the LN 31, and the input terminal of the inverter 20 via the LN 33. The primary side of the electromagnetic switch 26 is connected to the secondary side of the electromagnetic switch 26B via the LN 31B.

  In the inverter 20 of the present embodiment, when the power for control for operating the control unit 202 is supplied and the power for conversion supplied to the input of the inverter 20 is cut off, An abnormal state signal indicating the occurrence of 20 abnormal states is output. This is the first state.

When an abnormal state of the inverter 20 is detected by the self-diagnosis function of the inverter 20, an abnormal state signal indicating the occurrence of the abnormal state of the inverter 20 is output. This is the second state.
Prior to the first state, when the second state occurs, the inverter 20 outputs an abnormal state signal. The controller 29 detects this and cuts off the supply of power for conversion supplied to the input of the inverter 20. At this stage, the abnormal state signal output by the inverter 20 corresponds to the first state, but the abnormal state signal that has been output due to the occurrence of the second state is continuously output. Become.
Due to the control by the control unit 29, the state indicated by the abnormal state signal transitions from the occurrence of the second state to the occurrence of the first state. The control unit 29 that detects the state indicated by the abnormal state signal cannot distinguish whether the cause is caused by the occurrence of the second state or the occurrence of the first state. It can be used as an output of an abnormal state signal due to occurrence.

By controlling as described above, the power for conversion supplied to the input of the inverter 20 is cut off. According to said control, it acts so that the operation | movement of the inverter 20 may be stopped. Since the inverter 20 is in a state where an abnormality is detected by the self-diagnosis function,
It is guided to the safe side by the control that acts to stop the operation.

(Third embodiment)
A third embodiment will be described.
FIG. 12 is a block diagram showing a motor speed control system including the speed control panel of the present embodiment. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and differences from the configuration shown in FIG. 1 will be mainly described.

  The speed control panel 2 does not include at least the electromagnetic switch 21 and the electromagnetic switch 22. Since the speed control panel 2 of the present embodiment does not include the electromagnetic switch, the power control panel 1 supplies electric power to the electric motor 3 even when the inverter 20 cannot supply electric power to the electric motor 3. It is not possible.

  A connection switching unit 10 is provided on the input side of the inverter 20 shown in the figure. As described above, the connection switching unit 10 switches the connection state of the three-phase AC circuit so that the electric motor 3 is started by the Y-Δ start control. The inverter 20 of the present embodiment can also control the rotation speed of the electric motor 3 based on the electric power supplied via the connection switching unit 10.

  According to said embodiment, except the effect that the electric motor 3 can be driven when the inverter 20 shown in said embodiment cannot be functioned, the effect similar to the effect shown in said embodiment is acquired. Can do. In addition, the configuration of the speed control panel 2 can be simplified, and the casing of the speed control panel 2 can be further downsized. Thus, it is possible to arrange a speed control panel that enables speed control of the three-phase induction motor while utilizing a power control panel configured to stop and drive the Y-Δ switchable three-phase induction motor. It becomes easy.

  According to the embodiment described above, the speed control panel 2 includes the inverter that drives the electric motor 3 that can be switched between Y and Δ based on the electric power supplied from the power control panel 1. The inverter 20 is provided with a connection switching unit 10 on the input side for switching the connection state of the three-phase AC circuit so that the electric motor 3 is started by Y-Δ start control. The inverter 20 controls the drive speed of the Y-Δ switchable motor by controlling the rotational speed of the motor 3 based on the electric power supplied through the connection switching unit 10, and the power control panel 1. This makes it possible to control the speed of the electric motor 3.

  A program for realizing the speed control system 5 may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into the computer system and executed to perform various processes. . Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. For example, as the above-described modification, the arrangement of the above-described embodiment and the arrangement of functions may be rationally changed, or any one of a plurality of structures and functions may be arbitrarily combined and configured as an integrated unit. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Power control board, 2 ... Speed control board, 3 ... Electric motor, 5 ... Speed control system, 8 ... Central control apparatus, 10 ... Connection switching part, 20 ... Inverter, 29 ... Control part, 21, 22, 24, 25 , 26, 26B ... electromagnetic switches.

Claims (8)

An inverter for driving a three-phase induction motor capable of switching star delta (hereinafter referred to as “Y-Δ”) based on electric power supplied from a power control panel;
The inverter is
A connection switching unit that switches the connection state of the three-phase AC circuit so as to start the three-phase induction motor by Y-Δ start control is provided on the input side, and based on the electric power supplied through the connection switching unit, Control the rotational speed of the three-phase induction motor,
Speed control panel. The speed control panel according to claim 1, further comprising: a control unit that detects that the state of the connection switching unit is in a Δ connection state. The connection switching unit is included in a power control panel that enables the three-phase induction motor to be started by Y-Δ start control,
The inverter is
Housed in a housing provided outside the housing of the power control panel,
The speed control panel according to claim 1 or 2. The speed control panel according to claim 3, further comprising a drive mode switching unit that switches a power supply path to the three-phase induction motor to any one of a power supply path from the inverter and a power supply path from the power control panel. The drive mode switching unit
When the inverter cannot supply power to the three-phase induction motor, the power supply path to the three-phase induction motor is switched so as to supply power to the three-phase induction motor from the power control panel.
The speed control panel according to claim 4. The input-side power supply path switching unit that switches a power supply path between the connection switching unit and the inverter so as to correspond to the state of the connection switching unit. Speed control panel. A first terminal unit to which electric power is supplied from a power control panel including the connection switching unit;
A second terminal portion to which electric power is supplied from the power control panel;
With
Either one of the first terminal portion and the second terminal portion is
When the state of the connection switching unit is in the state of Y connection, the terminals for three-phase AC included in the terminal unit are connected to each other.
The speed control board according to any one of claims 1 to 5. A power control panel including a connection switching unit for starting the three-phase induction motor by Y-Δ start control, and converting the power supplied via the connection switching unit, and the speed of the three-phase induction motor by the converted power Adjusting the speed control panel, electrically connecting the step,
Electrically connecting the three-phase induction motor to the output side of the speed control panel;
A method for manufacturing a speed control system.

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