Interface circuit for motor drive

Abstract

The present invention relates to an interface circuit of a motor drive device, the interface circuit of the motor drive device comprising: a power supply circuit unit for driving and controlling a motor; and a control panel unit for controlling the power supply circuit unit and providing a user interface, the power supply circuit unit also comprising a second MCU, the second MCU controlling a relay and an additional device unit, and detecting an operating state of the additional device unit, the second MCU being able to communicate with a first MCU of a control panel unit via a communication line.

Description

Technical Field

[0001] The present invention relates to an interface circuit of a motor drive device, and more particularly to an interface circuit of a motor drive device capable of simplifying the structure and reducing the cost. Background Art

[0002] Generally speaking, the motor driving device includes: a power circuit unit for providing driving power to the motor; and a control panel for detecting and displaying the operating state of the power circuit unit and controlling the power circuit unit to comply with control instructions input through a user interface.

[0003] As mentioned above, equipment that uses high power and has parts that the user directly contacts must have insulation measures to ensure user safety.

[0004] In particular, the UL (Underwriters Laboratories) standard specifies insulation levels for a user interface and a power circuit portion of an inverter, and products that comply with such standards are produced.

[0005] Figure 1 It is an interface circuit diagram of a conventional motor drive device.

[0006] Reference Figure 1 The interface circuit of the conventional motor driving device includes a digital isolator 300 located between the power circuit part 200 and the control panel part 100 , and the digital isolator 300 performs digital insulation on all signals transmitted between the power circuit part 200 and the control panel part 100 .

[0007] The power circuit section 200 includes a circuit for driving a motor 207 , for example, a power supply section 201 , a converter section 202 , an inrush current suppression section 203 , a smoothing section 204 , a regenerative braking section 205 , and an inverter section 206 .

[0008] In addition, a gate driving section 210 for driving individual gate elements of the inverter section 206 and various sensors 220 are included, and a relay 240 and an additional device section 230 are included.

[0009] The control panel unit 100 includes: a user interface unit 110 , which is directly touched by a user; and an MCU 120 , which controls the power circuit unit 200 according to the input of the user interface unit 110 , detects the operation status of the power circuit unit 200 and displays it on the user interface unit 110 .

[0010] The configuration and function of each of the converter unit 202 , the inrush current suppression unit 203 , the smoothing unit 204 , the regenerative braking unit 205 , and the inverter unit 206 of the power circuit unit 200 are well known, and thus detailed description thereof will be omitted.

[0011] The power circuit unit 200 includes a gate driving unit 210 as a basic circuit configuration for driving the motor 207 , and can drive a plurality of gate elements provided in the inverter unit 206 .

[0012] In addition, an additional device unit 230 is included and operates under the control of the MCU 120. Examples of the additional device unit 230 include an air circulation device having a plurality of cooling fans and blowers, and an environmental monitoring device such as a temperature sensor and a humidity sensor.

[0013] As described above, various functional blocks of the power circuit unit 200 operate under the control of the control panel unit 100 .

[0014] The control panel unit 100 includes various sensors in order to grasp the operating state of the power circuit unit 200 and display it on the user interface unit 110 .

[0015] The signals of various sensors need to be insulated, and in order to achieve the insulation, a digital isolator 300 which is expensive and requires a relatively large installation area is used.

[0016] Figure 2 is a simplified block diagram of the digital isolator 300 .

[0017] The digital isolator 300 includes a plurality of optocouplers. In particular, in order to realize bidirectional insulation between the power supply circuit unit 200 and the MCU 120, it is necessary to use a bidirectional optocoupler 310 having a pair of light-emitting units 311, 314 and light-receiving units 312, 313 respectively arranged on one side. Therefore, there is a problem of inevitably increasing the cost and the installation area.

[0018] In particular, since it is necessary to provide a terminal of the digital isolator 300 for each additional device section 230 that is not closely related to the drive control of the motor 207 , there is a problem that an increase in cost and volume is inevitable. Summary of the invention

[0019] Problems to be solved by the invention

[0020] The technical problem to be solved by the present invention is to provide an interface circuit of a motor drive device which can reduce manufacturing costs and increase the margin of installation space.

[0021] Technical solutions to the problem

[0022] In order to solve the above technical problems, the interface circuit of the motor drive device of the present invention includes: a power supply circuit unit, which is used for driving control of the motor; and a control panel unit, which controls the power supply circuit unit and provides a user interface. The power supply circuit unit also includes a second MCU, which controls the relay and the additional device unit and detects the operating status of the additional device unit. The second MCU can communicate with the first MCU of the control panel unit through a communication line.

[0023] In an embodiment of the present invention, a digital isolator may be further included, wherein the digital isolator insulates the receiving and transmitting signals between the first MCU and a gate driving unit, wherein the gate driving unit is provided in the power circuit unit and controls the gate element of the inverter unit.

[0024] In an embodiment of the present invention, the digital isolator may insulate and provide a signal of a sensor part for detecting a driving state of the motor to the first MCU.

[0025] In an embodiment of the present invention, the second MCU may control the on-off of the gate element of the inverter part according to the control signal of the first MCU.

[0026] In an embodiment of the present invention, the additional device portion may include a cooling fan, a blower, or an environmental sensor.

[0027] In an embodiment of the present invention, the second MCU may set a priority for each of the additional device parts, and communicate with the first MCU according to the priority.

[0028] In the embodiment of the present invention, the second MCU may communicate with the first MCU only when the detection result of the additional device part changes.

[0029] In an embodiment of the present invention, the second MCU may cut off the relay according to the detection result of the additional device part.

[0030] Effects of the Invention

[0031] The present invention sets a separate MCU that communicates with the MCU of the control panel part in the power circuit part, uses data communication between them to perform control, limits the use of digital isolators, can reduce costs, and has the effect of ensuring a margin for installation space. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is an interface circuit diagram of a conventional motor drive device.

[0033] Figure 2 yes Figure 1 Figure 1. Block diagram of the digital isolator in Figure 1.

[0034] Figure 3 and Figure 4 They are interface circuit diagrams of a motor driving device according to an embodiment of the present invention.

[0035] Description of Reference Numerals

[0036] 10: Control panel 11: User interface

[0037] 12: First MCU 13: Communication line

[0038] 20: Power supply circuit section 30: Digital isolator

[0039] 40: Relay 50: Additional device

[0040] 60: Second MCU DETAILED DESCRIPTION

[0041] In order to fully understand the structure and effect of the present invention, the preferred embodiment of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but can be implemented in various forms and can be variously changed. However, the description of this embodiment is intended to provide a complete disclosure of the present invention and fully disclose the scope of the present invention to those of ordinary skill in the art to which the present invention belongs. In the accompanying drawings, for ease of explanation, the size of the constituent elements is enlarged, and the proportion of the constituent elements may be exaggerated or reduced.

[0042] The terms "first", "second", etc. can be used to describe various constituent elements, but these constituent elements should not be limited to the above terms. The above terms can only be used to distinguish one constituent element from another constituent element. For example, without departing from the scope of the present invention, the "first constituent element" can be named as the "second constituent element", and similarly, the "second constituent element" can also be named as the "first constituent element". In addition, unless the context clearly stipulates otherwise, the expression of the singular includes the expression of the plural. Unless otherwise defined, the terms used in the embodiments of the present invention can be interpreted as meanings known to those skilled in the art.

[0043] Hereinafter, an inverter protection device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0044] Figure 3 FIG. 4 is an interface circuit diagram of a motor driving device according to an embodiment of the present invention.

[0045] As shown in the figure, the interface circuit of the motor driving device of one embodiment of the present invention includes a power circuit unit 20 for driving a motor 27 and a control panel unit 10 for controlling the power circuit unit 20, wherein the power circuit unit 20 includes a second MCU 60 that communicates with a first MCU (Micro Controller Unit) 12 of the control panel unit 10 to monitor and control the status of a relay 40 and an additional device unit 50.

[0046] The digital isolator 30 insulates signals transmitted between the power circuit unit 20 and the control panel unit 10 without passing through the second MCU 60 .

[0047] The power circuit section 20 may include a circuit for driving the motor 27 , for example, a power supply section 21 , a converter section 22 , an inrush current suppression section 23 , a smoothing section 24 , a regenerative braking section 25 , and an inverter section 26 .

[0048] Here, the circuit for driving the motor 27 listed above is merely an example, and the configuration of the circuit may be changed as necessary.

[0049] The power circuit unit 20 includes a gate driving unit 28 that controls a gate element provided in the inverter unit 26 and a sensor unit 29 that detects a driving current of the motor 27 and provides an operating state of the motor 27 .

[0050] The control panel unit 10 may include: a user interface unit 11, which displays the operation status of the power circuit unit 20 including the operation status of the motor 27 so that the user can identify it, and can receive the user's control instructions; a first MCU 12, which controls the gate driving unit 28 through the digital isolator 30 and receives the signal of the sensor unit 29; and a communication line 13, which is used for data transmission between the first MCU 12 and the second MCU 60 of the power circuit unit 20.

[0051] In the above configuration, when an operation command is issued through the user interface 11, the first MCU 12 outputs various control signals according to the settings. At this time, the control signal for controlling the relay 40 and the control signal for controlling the additional device 50 are sent to the second MCU 60 of the power circuit 20 through the communication line 13.

[0052] The communication line 13 is determined according to the communication method between the first MCU 12 and the second MCU 60 , and a serial or parallel communication line may be used.

[0053] The second MCU 60 , which receives the control signal from the first MCU 12 , controls and drives the relay 40 and the additional device portion 50 .

[0054] In addition, a control signal of the first MCU 12 for controlling the inverter unit 26 is provided to the gate driving unit 28 through the digital isolator 30 , and the gate driving unit 28 drives the motor 27 by controlling the control state of the gate element provided in the inverter unit 26 .

[0055] At this time, the driving control of the motor 27 may be the rotation direction and speed.

[0056] The operating state of the motor 27 is detected by the sensor unit 29. The operating state detected by the sensor unit 29 is received by the first MCU 12 through the digital isolator 30, and the first MCU 12 displays the operating state of the motor 27 on the user interface unit 11 so that the user can recognize it.

[0057] The digital isolator 30 includes an optocoupler. Since it only insulates the limited signals, that is, the transmission and reception signals between the sensor unit 29 for detecting the movement of the gate driving unit 28 and the motor 27 and the first MCU 12, the number of optocouplers can be reduced. By reducing the number of optocouplers whose prices vary greatly depending on the insulation level, the cost can be reduced and the volume can be reduced.

[0058] During the operation of the motor 27 , the state of the additional device unit 50 is detected by the second MCU 60 .

[0059] Specifically, the additional device part 50 may be an air circulation device such as a cooling fan or a blower. In this case, the rotation speed of the cooling fan or the blower is detected by the second MCU 60 .

[0060] At this time, the detected information is sent to the first MCU 12 through the communication line 13 , and the first MCU 12 can display the rotation speeds of the cooling fan and the blower on the user interface 11 .

[0061] The present invention further includes a second MCU 60 having a feature of being able to control and detect information in a communication manner that does not require insulation from the first MCU 12, so that the amount of data communication through the communication line 13 may increase. In order to prevent this, the second MCU 60 may transmit information to the first MCU 12 through the communication line 13 only when the state of the relay 40 or the additional device part 50 changes.

[0062] For example, if the second MCU 60 detects that the rotation speed of the cooling fan of the additional device unit 50 drops sharply, it is determined that the cooling fan of the additional device unit 50 has failed, and the situation is transmitted to the first MCU 12 through the communication line 13 and displayed on the user interface unit 11 so that measures can be taken.

[0063] The interface unit 11 includes an alarm function and can generate an alarm when it is determined that an abnormality has occurred.

[0064] Another foreseeable effect of the present invention is that, compared with the conventional method of isolating all the data transmitted and received by the MCU of the control panel part, a faster control response speed can be expected by also using the control based on the communication between the first MCU 12 and the second MCU 60 .

[0065] For example, temperature information detected by the additional device part 50 as a temperature sensor is detected by the second MCU 60 , and the second MCU 60 can immediately control another additional device part 50 as a cooling fan according to the detected temperature.

[0066] This is because the second MCU 60, which detects a sharp rise in the temperature detected by the specific temperature sensor, sends the detection result of the temperature rise to the first MCU 12 of the control panel part 10, and at the same time controls the rotation speed of another additional device part 50 as a cooling fan to match the temperature, thereby being able to perform the response control for overheating more quickly.

[0067] In addition, the second MCU 60 may set a communication priority, set an importance level of each of the attachments 50 in the entire system, and provide information detected by an attachment 50 with a higher importance level to the first MCU 12 with priority over other information.

[0068] Through the above-described priority processing, it is possible to eliminate control processing delays due to communication congestion that may occur.

[0069] In addition, the second MCU 60 can provide a shutdown function. For example, when it is determined that the information detected by the humidity sensor, temperature sensor, etc. as the additional device part 50 may cause serious damage to the entire system, the control of disconnecting the relay 40 can be immediately executed. Therefore, it is possible to respond to emergency situations more quickly and prevent system damage.

[0070] Figure 4 FIG. 4 is an interface circuit diagram of a motor driving device according to another embodiment of the present invention.

[0071] Reference Figure 4 In the interface circuit of the motor drive device of another embodiment of the present invention, all signal transmission and reception between the control panel part 10 and the power circuit part 20 can be replaced by data communication between the first MCU 12 of the control panel part 10 and the second MCU 60 of the power circuit part 20.

[0072] Therefore, even without using the digital isolator 30 , an isolation state can be achieved.

[0073] In the above configuration, the second MCU 60 can directly control the gate driving unit 28 to control the gate element of the inverter unit 26 , and can receive and determine the driving state of the motor 27 detected by the sensor unit 29 .

[0074] At this time, the second MCU 60 may provide the information to the first MCU 12 only when the driving state of the motor 27 detected by the sensor part 29 changes. In addition, the gate driving part 28 may be controlled only when a control signal of the first MCU 12 for changing the driving control of the motor 27 is received to minimize the increase in the amount of communication through the communication line 13.

[0075] Although the embodiments according to the present invention are described above, these are merely exemplary, and those skilled in the art can implement various modifications and embodiments within the scope of equivalence. Therefore, the true technical protection scope of the present invention should be determined by the appended claims.

[0076] Industrial Applicability

[0077] The industrial applicability of the present invention lies in that it is a technology that can simplify the structure by utilizing the laws of nature to change the design of an interface for controlling a motor drive device.

Claims

1. An interface circuit for a motor drive device, comprising: A power circuit unit having an inverter unit for driving and controlling a motor, a gate driving unit for driving and controlling a gate of the inverter unit, a relay and an additional device unit, and a second MCU for controlling the relay and the additional device unit and detecting a state of the additional device unit; A control panel part is provided separately from the power circuit part and has a first MCU, the first MCU controls the gate driving part and is connected to the second MCU through a communication line to receive the states of the relay and the additional device part detected by the second MCU; as well as A digital isolator connects the power circuit unit and the control panel unit, and insulates the receiving and transmitting signals between the first MCU and the gate driving unit. The additional device section includes a cooling fan or a blower for cooling the power circuit section.

2. The interface circuit of the motor drive device according to claim 1, wherein: The digital isolator insulates a signal of a sensor unit that detects a driving state of the motor and provides the signal to the first MCU.

3. The interface circuit of the motor drive device according to claim 1, wherein: The second MCU sets a priority for each of the additional device units and communicates with the first MCU according to the priority.

4. The interface circuit of the motor drive device according to claim 1, wherein: The second MCU communicates with the first MCU only when the detection result of the additional device part changes.

5. The interface circuit of the motor drive device according to claim 1, wherein: The second MCU cuts off the relay according to the detection result of the additional device unit.

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