KR102591323B1 - Motor controlling apparatus - Google Patents

Abstract

A motor control device according to an embodiment of the present invention includes a power supply unit that supplies direct current voltage, a filter unit that removes noise components included in the direct current voltage, and a converter that converts the direct current voltage from which the noise component has been removed into a three-phase alternating current voltage in the form of a pulse. It includes an inverter unit that supplies power to the motor, and a reverse voltage prevention unit that blocks reverse current according to the supply of reverse voltage, wherein the first end of the reverse voltage prevention unit is connected to the ground terminal and the second end is connected to the filter unit. When the reverse voltage is supplied from the ground terminal and the reverse current is generated, the reverse current flowing to the filter unit is blocked.

Description

MOTOR CONTROLLING APPARATUS}

The embodiment relates to a motor control device.

The power supply unit 10, which provides power to the motor, supplies direct current component current to the inverter, but the actual current input to the inverter is supplied in the form of pulses in which both direct current component and alternating current component exist. This is because noise generated by electromagnetic interference or electromagnetic interference has an effect. Therefore, the EMC (Electro Magnetic Compatibility) filter 11 is used to remove the AC component, which is noise, before the current is applied to the inverter. At this time, the EMC filter 11 is mainly used as a pi filter. The pi filter is divided into a CLC filter and a CRC filter. The CLC filter, which is implemented with two capacitors (12, 14) and one inductor (13), has high filtering efficiency.

Figure 1 is a schematic diagram showing the input circuit of a motor controller using a conventional EMC filter.

Referring to Figures 1 and 2, the input circuit of a conventional motor controller consists of an EMC filter 11 and a reverse voltage prevention unit 15 to prevent reverse voltage applied to the inverter. Additionally, the EMC filter 11 is disposed between the power supply unit 10 and the reverse voltage prevention unit 15 to increase the filtering effect. When using a pi filter as the EMC filter (11), the capacitance of the capacitors (12, 14) included in the EMC filter (11) must have a size of hundreds to thousands of μF. In order to satisfy this capacitance capacity, the EMC filter (11) Electrolytic capacitors are mainly used as the capacitors 12 and 14.

However, this input circuit has a problem in that it does not protect the EMC filter 11 from the reverse voltage applied from the ground terminal. In particular, since electrolytic capacitors have polarity, they are damaged when a reverse voltage is applied to the ground terminal, causing electrolyte leakage.

To solve this problem, when using a multi-layer ceramic capacitor or film capacitor without polarity, the capacitor can be prevented from being damaged even if a reverse voltage is applied. However, the capacitance capacity is lowered and the filtering efficiency is reduced. Therefore, multiple capacitances must be connected to meet the required capacity, but capacitors without polarity, such as multilayer ceramic condensers or film capacitors, are expensive, increasing the manufacturing cost of the input circuit. In addition, since multiple elements must be connected, an additional problem of lowering the durability of the circuit occurs.

Another method is to change the positions of the EMC filter 11 and the reverse voltage prevention unit 15, but the distance between the input terminal of the power unit 10 and the EMC filter 11 increases, causing a problem in that filtering efficiency is reduced. do.

The technology behind the present invention is disclosed in Korean Patent Publication No. 10-2010-0043387 (published on April 29, 2010).

The embodiment is intended to provide a motor control device for protecting the EMC filter of the motor control device from reverse voltage.

The problem to be solved in the embodiment is not limited to this, and it will also include means of solving the problem described below and purposes and effects that can be understood from the embodiment.

A motor control device according to an embodiment of the present invention includes a power supply unit that supplies direct current voltage, a filter unit that removes noise components included in the direct current voltage, and a converter that converts the direct current voltage from which the noise component has been removed into a three-phase alternating current voltage in the form of a pulse. It includes an inverter unit that supplies power to the motor, and a reverse voltage prevention unit that blocks reverse current according to the supply of reverse voltage, wherein the first end of the reverse voltage prevention unit is connected to the ground terminal and the second end is connected to the filter unit. When the reverse voltage is supplied from the ground terminal and the reverse current is generated, the reverse current flowing to the filter unit is blocked.

The filter unit includes a first capacitor whose first end is connected to the power supply, a second end connected to the reverse voltage prevention unit, an inductor whose first end is connected to the first end of the first capacitor, and a first capacitor. It may include a second capacitor, the terminal of which is connected to the second terminal of the inductor, and the second terminal of which is connected to the second terminal of the first capacitor.

The first capacitor and the second capacitor may include a positive terminal and a negative terminal.

The first capacitor and the second capacitor may have a capacitance greater than 100 μF.

The first capacitor and the second capacitor may include an electrolytic capacitor.

According to an embodiment, the EMC filter of the motor controller input circuit can be protected from reverse voltage.

The various and beneficial advantages and effects of the present invention are not limited to the above-described content, and may be more easily understood through description of specific embodiments of the present invention.

Figure 1 is a schematic diagram showing the input circuit of a motor controller using a conventional EMC filter.
Figure 2 is a schematic diagram of a motor control device according to an embodiment of the present invention.
Figure 3 is a circuit diagram of a motor control device according to an embodiment of the present invention.
Figure 4 is a circuit diagram showing a motor control system using a motor control device according to an embodiment of the present invention.

Since the present invention can be subject to various changes and can have various embodiments, specific embodiments will be illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms containing ordinal numbers, such as second, first, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, the second component may be referred to as the first component without departing from the scope of the present invention, and similarly, the first component may also be referred to as the second component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Hereinafter, embodiments will be described in detail with reference to the attached drawings, but identical or corresponding components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

Let us look at the motor control device according to an embodiment of the present invention through Figure 2.

Figure 2 is a schematic diagram of a motor control device according to an embodiment of the present invention.

2 and 3, the motor control device 100 according to an embodiment of the present invention includes a power supply unit 110, a filter unit 120, an inverter unit 130, and a reverse voltage prevention unit 140. .

The power supply unit 110 supplies direct current voltage. The power supply unit 110 is a direct current power device that supplies direct current voltage, and may be implemented in the form of a battery, but is not limited thereto and may include any device that can store direct current voltage and supply it to the load end.

The filter unit 120 removes noise components included in the direct current voltage. The direct current voltage applied from the power supply unit 110 may include not only a direct current component but also an alternating current component. At this time, the alternating current component may be noise, that is, a ripple component, generated by conducted emission (CE), which is a phenomenon of unnecessary electromagnetic energy generated through a conductor from surrounding electronic devices, etc. The filter unit 120 can remove noise components, which are alternating current components, from the direct current voltage directly supplied from the input terminal of the power supply unit 110.

At this time, the filter unit 120 may be implemented as an EMC filter or as a pi filter (π filter). The pi filter includes a CLC filter consisting of two capacitors and one inductor and a CRC filter consisting of two capacitors and one resistor element.

Meanwhile, the filter unit 120 can remove noise components from the direct current voltage supplied from the power supply unit 110 and then transfer it to the inverter unit 130.

The inverter unit 130 converts the direct current voltage from which noise components have been removed into pulse-shaped three-phase alternating current voltage and supplies it to the motor. The inverter unit 130 may include a plurality of switch elements to convert direct current voltage to three-phase alternating current voltage, a gate driver for controlling the switch elements, and a controller for controlling the gate driver. The inverter unit 130 controls the gate element to transmit a switching signal to a plurality of switches through a controller, and the plurality of switching elements perform a turn-on or turn-off operation according to the switching signal, thereby generating a three-phase alternating current voltage. At this time, the inverter unit 130 can control the speed of the motor 150 by controlling the switching speed and converting the frequency of the three-phase alternating current voltage.

The reverse voltage prevention unit 140 blocks reverse current due to reverse voltage supply. Specifically, the reverse voltage prevention unit 140 may have a first end connected to a ground terminal and a second end connected to the filter unit 120. That is, the reverse voltage prevention unit 140 may be disposed between the ground terminal and the filter unit 120. Here, the ground terminal may be the same terminal as the negative terminal of the power supply unit 110. When a reverse voltage is supplied from the ground terminal and a reverse current is generated, the reverse voltage prevention unit 140 blocks the reverse current flowing to the filter unit 120. The reverse voltage prevention unit 140 may be implemented in the form of a semiconductor device such as a diode that passes current in only one direction or a circuit implemented with a plurality of devices.

Figure 3 is a circuit diagram of a motor control device according to an embodiment of the present invention.

Referring to FIG. 3, the filter unit 120 may be implemented as a CLC filter, and therefore may include two capacitors 121 and 123 and one inductor 122. In addition, the filter unit 120 may be implemented as a CRC filter, and in this case, it may include a resistor element instead of the inductor 122.

The first capacitor 121 of the filter unit 120 has a first end connected to the power supply unit 110 and a second end connected to the reverse voltage prevention unit 140. That is, the first terminal of the first capacitor 121 is connected to the positive terminal of the power supply unit 110 that supplies direct current voltage. And, the first end of the inductor 122 of the filter unit 120 is connected to the first end of the first capacitor 121. And, the first end of the second capacitor 123 of the filter unit 120 is connected to the second end of the inductor, and the second end is connected to the second end of the first capacitor 121.

Referring to the circuit structure of the filter unit 120 of FIG. 3, as the capacitance of the first capacitor 121 and the second capacitor 123 increases, the time constant of the filter unit 120 decreases, and the time constant of the inductor 122 decreases. As the inductance increases, the time constant of the filter unit 120 decreases. As the time constant decreases, the commutation time becomes shorter and the cutoff frequency becomes lower. On the other hand, as the time constant increases, the commutation time becomes longer and the blocking frequency increases. That is, as the capacitance capacity of the first capacitor 121 and the second capacitor 123 increases, the noise filtering effect increases and the filtering speed also becomes faster.

Accordingly, the first capacitor 121 and the second capacitor 123 of the filter unit 120 according to an embodiment of the present invention may be composed of capacitors having a capacitance value greater than 100 μF. And, the first capacitor 121 and the second capacitor 123 may include a positive terminal and a negative terminal. That is, the first capacitor 121 and the second capacitor 123 may be capacitors with polarity. Accordingly, the first capacitor 121 and the second capacitor 123 may be implemented as electrolytic capacitors, but are not limited thereto.

Unlike the circuit shown in FIG. 3, when the reverse voltage prevention unit 140 is not connected to the second terminal of the first capacitor 121, the second terminal of the first capacitor 121 is connected to the ground terminal, At this time, if a reverse voltage is applied from the ground terminal, the first capacitor 121, which has polarity, may be damaged. However, the motor 150 control device 100 according to an embodiment of the present invention is implemented in a structure in which the reverse voltage prevention circuit is disposed between the first capacitor 121 and the ground terminal, so even if voltage is applied from the ground terminal. Since the reverse current cannot flow through the filter unit 120, the first capacitor 121 can be protected.

Meanwhile, in order to prevent damage to the first capacitor 121 and the second capacitor 123, a multilayer ceramic capacitor or film capacitor without polarity may be disposed, but in the case of a multilayer ceramic capacitor or film capacitor, the capacitance capacity is small. Filtering efficiency will greatly decrease, and if the number is increased to increase capacitance capacity, not only will the manufacturing cost greatly increase, but the circuit configuration may be complicated and durability may be lowered.

In addition, when the reverse voltage prevention unit 140 is disposed on the positive terminal side of the power supply unit 110, the flow of reverse current can be blocked, but the filter unit 120 is connected to the power supply unit via the reverse voltage prevention unit 140. Since direct current voltage is supplied from (110), the filtering efficiency of the filter unit 120 is lowered. However, the motor 150 control device 100 according to an embodiment of the present invention directly connects the positive terminal of the power supply unit 110 and the filter unit 120 by connecting the reverse voltage prevention unit 140 to the ground terminal. This has the advantage of maintaining the efficiency of the filter unit 120.

However, as in the embodiment of the present invention, the above problem can be solved when the reverse voltage prevention unit 140 is disposed between the second terminal of the first capacitor 121 and the ground terminal.

Figure 4 is a circuit diagram showing a motor control system using a motor control device according to an embodiment of the present invention.

Referring to FIG. 4, the motor control system according to an embodiment of the present invention includes a power supply unit 110, a filter unit 120, an inverter unit 130, a reverse voltage prevention unit 140, and a motor 150.

The configuration of the power supply unit 110, filter unit 120, and reverse voltage prevention unit 140 has been examined in detail with reference to FIG. 3, and detailed description will be omitted.

As shown in FIG. 4, the inverter unit 130 may include a plurality of switching elements, a plurality of gate drivers, and a controller (not shown) that controls the plurality of gate drivers.

Specifically, the plurality of switching elements may be implemented as six switching elements. The plurality of switching elements may be implemented as an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

In addition, the plurality of gate drivers can be implemented as a high-side driver that controls three switching elements connected to the filter unit 120 among the six switching elements and a low-side driver that controls three switching elements connected to the ground terminal. there is. The high-side driver and low-side driver can each turn on one switching element under the control of the controller. At this time, when switches of the same phase are turned on at the same time, no voltage is applied to the motor 150, so switches located in different phases can be turned on. Therefore, six switching states may exist.

The motor 150 refers to a power device that rotates by electrical energy and generates rotational force on its axis. Depending on the electrical type of the output power, there are three types: direct current, single-phase alternating current, and three-phase alternating current. In this embodiment, the motor 150 is connected to the output terminal of the three-phase AC power of the inverter and includes a three-phase induction motor driven by the three-phase AC power of the inverter, and includes a brushless DC motor. . According to an embodiment of the present invention, the three-phase alternating current voltage generated by the inverter unit 130 through a switching operation changes the magnetic field in the stator of the brushless direct current motor and rotates the rotor, thereby driving the motor 150. .

The term '~unit' used in this embodiment refers to software or hardware components such as FPGA (field-programmable gate array) or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card.

Although the above description focuses on the examples, this is only an example and does not limit the present invention, and those skilled in the art will be able to You will see that various variations and applications are possible. For example, each component specifically shown in the examples can be modified and implemented. And these variations and differences in application should be construed as being included in the scope of the present invention as defined in the appended claims.

100: motor control device
110: power unit
120: filter part
130: Inverter unit
140: Reverse voltage prevention unit
150: motor

Claims (5)

A power supply unit that supplies direct current voltage,
A filter unit that removes noise components included in the direct current voltage,
An inverter unit that converts the direct current voltage from which the noise component has been removed into pulse-shaped three-phase alternating current voltage and supplies it to the motor, and
Includes a reverse voltage prevention unit that blocks reverse current due to reverse voltage supply,
The filter unit,
A first capacitor whose first end is connected to the power supply and whose second end is connected to the reverse voltage prevention unit, an inductor whose first end is connected to the first end of the first capacitor, and a first end of which is the inductor. It includes a second capacitor connected to the second terminal of the first capacitor, the second terminal of which is connected to the second terminal of the first capacitor,
The first capacitor and the second capacitor have a positive terminal and a negative terminal,
The first capacitor and the second capacitor have a capacitance value greater than 100 μF,
The reverse voltage prevention unit has a first end connected to a ground terminal and a second end connected to the second end of the first capacitor and is disposed between the ground terminal and the first capacitor, so that the reverse voltage is applied at the ground terminal. When supplied and the reverse current is generated, a motor control device blocks the reverse current flowing from the ground terminal to the first capacitor. delete delete According to paragraph 1,
The first capacitor and the second capacitor are,
Motor control devices with capacitance values greater than 100 μF. According to paragraph 1,
The first capacitor and the second capacitor are,
Motor control device containing electrolytic capacitors.