JP5662008B2 - Control system for power supply to the load - Google Patents

Description

  The present invention relates to a control system for controlling power supply to a load such as a motor.

  Conventionally, motors have been used in devices such as air conditioners and plants (see Non-Patent Document 1). As shown in FIG. 5, in order to control the operation of the motor 14, a driver circuit 16 b and a command device 18 are used in the control system 50. The driver circuit 16b includes a rectifier circuit 26 and a smoothing capacitor C1 that generate DC power from AC power, an inverter circuit 22 that supplies AC current to the motor 14, and a controller 24 that controls switching of the inverter circuit 22. The command device 18 transmits command data of switching timing to the controller 24, and the controller 24 controls switching of the inverter circuit 22 according to the command data, whereby an alternating current is supplied to the motor 14 at a predetermined timing.

  As the number of motors 14 increases, the number of driver circuits 16b also increases. It is necessary to connect the command device 18 to each driver circuit 16b, and the number of wirings increases. The burden of installation and maintenance of the motor 14 and its peripheral circuits increases. If it is the following patent document 1, since the instruction | command is sent using the wiring for exclusive use with respect to a motor, the burden of installation or a maintenance will become large.

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  An object of the present invention is to provide a load control system that is easy to install and maintain.

  The load control system of the present invention includes a power line, a driver circuit connected to the power line and controlling driving of the load while supplying power to the load, and command data for driving the load to the driver circuit via the power line. And a command device for sending.

  The control system of the present invention transmits command data from the command device to the driver circuit via the power line. No dedicated wiring is provided between the command unit and the driver circuit.

It said driver circuit comprises an inverter circuit having a plurality of switching elements, in accordance with the directive data from the command unit, and a controller for controlling the switching of the switching element.

  A circuit is provided that generates a pulse that is connected to the power line and reverses its polarity according to the content of the command data. As for the pulse, an asynchronous method is used, or the pulse width is varied according to command data.

  The driver circuit includes a rectifier circuit for supplying a DC voltage to the inverter circuit and the controller, and supplies a pulse to the controller from the command side of the rectifier circuit.

  A motor that controls operation by providing a plurality of loads and driver circuits by branching a plurality of power lines with respect to one commander, providing an address for each driver circuit, and including address data in a pulse Is determined.

  According to the present invention, since a power line for supplying power to a load is used for transmitting command data, installation and maintenance are facilitated. The greater the number of loads installed, the greater the difference in installation and maintenance burden compared to the prior art.

It is a figure which shows the structure of the control system of the load of this invention. It is a figure which shows an example which converted the command data into the pulse. It is a figure which shows an example of the pulse generation circuit used for a control system. It is the figure which applied the control system of the present invention to a plurality of loads. It is a figure which shows the structure of the conventional load control system.

  The load control system of the present invention will be described with reference to the drawings. The load will be described using a motor, but is not limited to a motor.

  The control system 10 of FIG. 1 includes a power line 12, a driver circuit 16 that directly controls driving of the motor 14, and a command unit 18 that sends command data for driving the motor 14 to the driver circuit 16.

  The power line 12 is used to transmit power and command data from the power source 20. Conventionally, the power line 12 has been used only to supply power to the motor 14 and the driver circuit 16, but in the present invention, it is also used to transmit command data.

  The driver circuit 16 controls driving of the motor 14 while supplying electric power to the motor 14. The driver circuit 16 includes an inverter circuit 22 including a plurality of switching elements, and a controller 24 that controls switching of the switching elements. By controlling the switching timing with respect to the switching element, the timing of the output AC voltage is controlled, and the driving of the motor 14 is controlled. An example of the controller 24 is a microcomputer.

  The driver circuit 16 includes a rectifier circuit 26 in front of the inverter circuit 22 and the controller 24 in order to supply a DC voltage to the inverter circuit 22 and the controller 24. The rectifier circuit 26 uses a plurality of diodes. In order to remove the ripple of the voltage converted into a direct current by the rectifier circuit 26, a smoothing capacitor C1 is provided at the subsequent stage of the rectifier circuit 26. If necessary, a DC / DC converter may be provided between the rectifier circuit 26 and the controller 24 to convert the voltage into a desired voltage for driving the controller 24.

  The command device 18 is a device that generates command data for driving the motor 14 at a predetermined rotational speed. The command device 18 includes a computer, and generates command data by hardware, software, or both.

  In order to transmit the command data, a pulse generation circuit 28 that generates a pulse according to the content of the command data is provided in the middle of the power line 12. The pulse generation circuit 28 converts the AC voltage output from the power supply 20 into a pulse whose polarity is inverted. Examples of the pulse type include a start bit, a start bit, a data bit including information such as the number of revolutions of the motor 14 (usually 8 bits including a parity bit as required), and a start-stop synchronization type including a stop bit. (FIG. 2). The number of data is set as appropriate according to the information. As another method, the rotation speed of the motor 14 may be changed according to the pulse width.

  The configuration of the pulse generation circuit 28 includes a rectifying / smoothing circuit 30 for converting the output of the AC power supply 20 into a direct current, and an H-bridge type inverter circuit 32 for generating a pulse (FIG. 3). The H-bridge type inverter circuit 32 has a plurality of switches SW1 to SW4, and pulses can be generated by the commander 18 directly or indirectly controlling the switching of the switches SW1 to SW4. By switching the switches SW1 and SW4 as a pair and the switches SW2 and SW3 as a pair and controlling on / off, a pulse whose polarity (plus potential and minus potential) is inverted can be generated. Examples of the switches SW1 to SW4 include transistors. Since the polarity of the pulse is inverted, the same rectifier circuit 26 and smoothing capacitor C1 can be used. It can be easily configured with a simple circuit without using a high-performance IC.

  Since the AC power source 20 is used, the rectifying / smoothing circuit 30 is used for the pulse generation circuit 28. However, if the DC power source is used, the rectifying / smoothing circuit 30 is omitted.

  It is necessary to input the command data to the controller 24. At this time, if the pulse passes through the rectifier circuit 26, the pulse is converted to a direct current, so that command data cannot be input to the controller 24. Therefore, a pulse is input to the controller 24 from the pulse generation circuit 28 side than the rectification circuit 26. In order to adjust the potential of the pulse, the pulse is input to the controller 24 via the voltage dividing resistors R1 and R2. The voltage dividing resistors R1 and R2 have a function of a command data detection circuit, and do not require a high-performance, high-frequency drive IC, and can detect the command data with a simple circuit.

  Note that when command data is transmitted simultaneously with the activation of the control system 10, the power supply to the controller 24 and the input of the command data become almost simultaneous. Since the control may become unstable, it is preferable to use only power supply immediately after startup.

  The operation of the control system 10 is as follows: (1) Command data is transmitted from the command device 18 to the pulse generation circuit 28. (2) The pulse generation circuit 28 generates a pulse corresponding to the command data and transmits it to the driver circuit 16 via the power line 12. The pulse is input to the controller 24 as command data and converted into a direct current by the rectifier circuit 26 for use. (3) The controller 24 controls switching of the inverter circuit 22 based on the command data. Power can be supplied to the motor 14 based on the command data by switching.

  Further, when a plurality of motors 14 are installed, there is a case where one power source 20 is branched to a plurality of power lines 12 (FIG. 4). In this case, the pulse generation circuit 28 and the command device 18 are provided on the power supply 20 side of the branch point of the power line 12. An address is provided for each controller 24 provided in the driver circuit 16, and the address is included in the contents of the command data. Although the command data is transmitted to all the controllers 24, the controller 24 executes only the command data including its own address.

  As described above, the control system 10 of the present invention has a small installation and maintenance burden because there is no dedicated wiring for connecting the commander 18 and the controller 24 of the driver circuit 16. The greater the number of motors 14 installed, the greater the difference in installation and maintenance burden from the prior art. Further, the circuit configuration is merely an increase in the number of circuits for performing transmission using the power line 12 as compared with the prior art, and the circuit is hardly complicated.

  As mentioned above, although embodiment was described about this invention, this invention is not limited to said embodiment. For example, when the driver circuit 16 is used for a lighting circuit of a lighting fixture or a high-frequency power generator for induction heating, a fluorescent lamp or an induction heating coil is used instead of the motor 14.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

10: Control system 12: Power line 14: Motor (load)
16: Driver circuit 18: Commander 20: Power supply 22: Inverter circuit 24: Controller 26: Rectifier circuit 28: Pulse generator circuit 30: Rectifier smoothing circuit 32: H bridge type inverter circuit C1: Smoothing capacitors R1, R2: Voltage dividing resistors SW1, SW2, SW3, SW4: Switch

Claims (4)

A control system for controlling power supply to a load,
Power lines,
A driver circuit connected to the power line and controlling driving of the load while supplying power to the load;
A commander for sending command data for driving the load to the driver circuit via the power line;
A circuit that is connected to the power line and generates a pulse whose polarity is inverted according to the content of the command data;
With
The driver circuit is
An inverter circuit comprising a plurality of switching elements;
And a controller for controlling switching of the switching element in accordance with command data from the command device,
A rectifier circuit for supplying a DC voltage to the inverter circuit and the controller;
With
A control system for supplying a pulse to the controller via a voltage dividing resistor from the command side of the rectifier circuit. The load is divided into a plurality of power lines for one commander, and the load and the driver circuit are plural. An address is provided for each driver circuit, and the address data is included in the command data to control the operation. 2. The control system according to claim 1, wherein the load is determined. 3. The control system according to claim 1, wherein the voltage dividing resistor functions as a command data detection circuit . The control system according to claim 1, wherein the circuit that generates the pulse includes an H-bridge type inverter circuit including a plurality of switches.

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