KR20120105138A - Switching noise removal apparatus - Google Patents

Abstract

PURPOSE: A switching noise removal apparatus is provided to prevent an abnormal operation and errors of an electronic device in a hybrid vehicle by minimizes influence of electromagnetic waves by preventing transition and radiation of switching noise using a power line. CONSTITUTION: A core(21) is formed into a ring shape. A wire(22) is wound around the core the predetermined number of times. The wire comprises first and second wires(23,24) which form outbound and inbound paths. The first and second wires are divided into two lines, respectively and are wound around the core. A cover(25) shields the core around which the wire is wound.

Description

Switching Noise Reduction Device {SWITCHING NOISE REMOVAL APPARATUS}

The present invention relates to a switching noise removing device, and more particularly to a switching noise removing device for removing the switch noise generated in the brushless DC motor applied to the oil pump of the hybrid vehicle.

In general, a hybrid electric vehicle refers to an efficient combination of two or more different power sources to drive a vehicle, and in most cases, an electric motor driven by an engine and a battery power that obtains driving power using fuel Refers to a vehicle that obtains a driving force.

In response to the recent demand for improving fuel economy and developing more eco-friendly products, research on hybrid vehicles is being actively conducted.

Hybrid vehicles can form a variety of structures using engines and electric motors as power sources. Hybrid vehicles that have been studied to date are either parallel or in series.

On the other hand, the hybrid vehicle is provided with an oil pump (Oil Pump) for supplying the necessary hydraulic fluid to the engine clutch and the transmission provided between the engine and the electric motor.

The oil pump supplies hydraulic oil to cylinders, pistons, crankshaft bearings, camshaft bearings, etc., which are in high temperature due to the heat generated by the explosion stroke of the engine, thereby cooling and lubricating.

That is, the hybrid control unit (hereinafter referred to as 'HCU') and the motor control unit (hereinafter referred to as 'MCU') are the target rotation speed and actual rotation speed of the oil pump motor through CAN communication. It controls by sending and receiving information such as operation status of oil pump, that is, normal or fault condition.

Here, the MCU calculates the target rotation speed according to the driving state and the driver operation state of the vehicle, and drives the oil pump motor according to the target rotation speed, so that the oil pump supplies the operating oil required for the engine clutch and the transmission.

The applicant of the Korean Patent Application No. 10-2008-0071452 (filed on July 23, 2008), 10-2008-0085730 (filed on September 1, 2008), 10-2009-0026798 (2009 And filed on March 30, 2008, 10-2009-0027919 (filed April 1, 2009), and the like, and disclosed and applied to an oil pump driving device for a hybrid vehicle.

Such an oil pump motor generally includes a brushless direct current motor (hereinafter, referred to as a motor) that is highly efficient, has a long service life, and has high reliability.

Since the motor is operated by current distributed at predetermined angles during rotation, the conventional oil pump driving device is provided with a dedicated controller control circuit for controlling the driving of the motor.

That is, the control circuit supplied with the DC power distributes the current for each predetermined angle when the motor rotates, and controls it to be supplied to each phase winding of the motor.

The switching noise is generated during the current switching operation according to the control of the control circuit. The switching noise is transferred to other control devices such as HCU, MCU, ECU, etc. of the hybrid vehicle connected through the power line or radiated in the air. Influence of other control devices inside the pump drive caused the abnormal operation and error.

In particular, since the oil pump driving device of the hybrid vehicle uses a high current of about 50 A, there is a problem that a general switching noise filter having a current capacity of 10 A or less cannot be applied.

The present invention is to solve the problems described above, an object of the present invention is to provide a switching noise removal device for preventing the transition and radiation of the switching noise generated in the switching unit for driving the motor for the oil pump applied to the hybrid vehicle To provide.

Another object of the present invention is to provide a switching noise removing apparatus that can minimize the size by increasing the rated current of the switching noise filter and simplifying the structure.

According to a feature of the present invention for achieving the above object, the present invention is a switching noise removing device for removing the switching noise generated during the operation of distributing the current for driving the motor, the switching noise removing device is a power source It is a common mode filter that is installed at the input stage and has two choke coils integrated into one.

The common mode filter includes a core formed in a ring shape and a wire wound around the core a predetermined number of times, and the wire includes first and second wires forming a return path and a return path, and the first and second wires. Are each branched into two wires and wound around the core.

The first and second wires branched into the two wires are wound five times on the core.

The diameters of the first and second wires branched into the two wires are 2.3 mm.

The common mode filter further includes a cover that shields the core around which the wire is wound, and the cover is formed with an insertion hole into which the wire is inserted.

As described above, the present invention eliminates switching noise generated during the switching operation to distribute current to each phase winding of the oil pump motor applied to the hybrid vehicle using the common mode filter.

Accordingly, the present invention can prevent the abnormal operation and error of other electronic devices provided in the hybrid vehicle by minimizing the influence of electromagnetic waves by blocking the transition and radiation of the switching noise using the power line.

In addition, the present invention increases the cross-sectional area of the entire wire by dividing a pair of wires wound around the core into two wires each, while reducing the diameter of the wire to improve the workability of winding the wire around the core, and common mode filter. By reducing the size of the electromagnetic shielding configuration can be minimized.

In addition, the present invention can increase the current capacity of the common mode filter to be applicable to a hybrid vehicle using a high voltage.

In addition, the present invention can minimize the switching operation timing deformation of the switching element due to the switching noise to reduce the amount of heat generated by the motor, it is possible to maximize the power supplied to the motor.

As a result, the present invention has the effect of improving the efficiency of the oil pump motor.

1 is a block diagram of a motor driving device for an oil pump to which a switching noise removing device according to an exemplary embodiment of the present invention is applied.
2 is a plan view of the switching noise removing device shown in FIG.
3 is a side view of the switching noise removing device shown in FIG.

Hereinafter, a switching noise removing apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the present embodiment, an oil pump motor driving device applied to a hybrid vehicle will be described as an example.

However, the present invention is not necessarily limited thereto, and it should be noted that the present invention may be applied to a motor driving apparatus of a BLDC motor using a high current.

1 is a block diagram of a motor driving apparatus for an oil pump to which a switching noise removing device according to an exemplary embodiment of the present invention is applied, and FIGS. 2 and 3 are plan and side views of the switching noise removing device shown in FIG. 1.

As shown in FIG. 1, the motor driving apparatus 10 for an oil pump to which the switch noise control device is applied according to a preferred embodiment of the present invention is a high voltage battery (not shown) or a battery (not shown) provided in a hybrid vehicle. Power conversion circuit 11 for converting the voltage level of the DC power supplied from the power supply, switching unit 12, the motor 13 to switch the DC power converted in the power conversion circuit 11 to supply to the motor 13 Control unit 14 for controlling the switching unit 12 so as to distribute the converted DC power for each specified angle during rotation to supply to each phase winding of the motor 13 and the switching unit is installed in the power input terminal receiving the DC power And a switching noise removing device 15 for removing the switching noise generated at 12.

In this embodiment, the motor 13 uses a three-phase BLDC motor.

The power conversion circuit 11 is required to drive the motor 13 with a DC power of about 12V supplied through a voltage conversion module (not shown) for converting the voltage level of the high voltage supplied from the high voltage battery or directly supplied from the battery. It converts to voltage level.

The switching unit 12 is a three-phase full bridge circuit composed of six metal oxide field effect transistors (called MOSFETs) that are selectively turned on and off according to a control signal of the controller 14. (3-phase full bridge circuit).

Here, switching noise is generated during the on / off operation of the MOSFET provided in the switching unit 12.

The switching noise removing device 15 serves to block the switching noise generated by the switching unit 12 from being transferred to other control devices such as HCU, MCU, ECU of the hybrid vehicle or radiated into the air through the power line.

As shown in FIGS. 2 and 3, the switching noise removing device 15 is a common mode filter 20 having a structure in which two choke coils are integrated into one.

The common mode is a conduction mode that flows in the same direction with respect to a return path and a return path. The common mode noise is generated by impedance unbalance of a wiring system, and is generally generated at a high frequency, but is strongly generated even at a low frequency in an oil pump motor. do.

 The common mode noise is transmitted to the ground and returned by drawing a large loop, which causes various noise disturbances to distant electronic devices.

For example, high-speed interface cables such as USB and IEEE 1394 perform high-speed data communication in a differential transmission scheme in which signals having different phases of 180 ° are transmitted to two signal lines (twisted pair lines).

The differential transmission method has a low emission noise and is hardly influenced by external noise. However, in the actual circuit, common mode noise occurs due to an unbalanced communication characteristic between two stranded signal lines, and the generated common mode noise is a power source. It may be transferred to other control devices through a line, or may be radiated into the air using a power line as an antenna.

That is, the common mode filter 20 serves to remove the common mode noise as described above.

To this end, as shown in FIGS. 2 and 3, the common mode filter 20 includes a core 21 formed in a ring shape, a wire 22 wound around a predetermined number of times, and a wire 22 wound on the core 21. A cover 25 for shielding the wound core 21 is provided.

The cover 25 is formed with a plurality of insertion holes into which the wire 22 is inserted.

The core 21 is mounted on the cover 25, and is manufactured in a ring shape using a ferrite material having a high magnetic permeability.

The wire 22 includes a first wire 23, which is a return path, to which a DC power is applied, and a second wire 24, which is a return path.

The diameter of the wire 22 and the number of times wound around the core 21 are set based on the current capacity of the common mode filter 20.

Since the configurations of the first wire 23 and the second wire 24 are the same, only the first wire 23 will be described below for convenience of description.

As the cross-sectional area of the first wire 23 increases, the current capacity of the common mode filter 20 increases.

However, since the larger the diameter of the first wire 23, the more work and effort required to wind the core 21, and larger than the limit diameter can not be wound around the core, so in the present embodiment the first wire 23 is The wires are branched to the first and second wires 231 and 232 to be wound around the core 21 so as to easily perform the wire winding operation while maintaining the same cross-sectional area.

Here, the diameters of the first and second wires 231 and 232 of the first wire 23 are set to about 2 to 2.5 mm, preferably about 2.3 mm.

If the number of times the first wire 23 is wound around the core 22 increases, the current capacity of the common mode filter 20 increases. However, if the number of windings of the first wire 23 is excessively increased, the DC current supplied through the first wire 23 may decrease.

Therefore, in the present embodiment, the first and second wires 231 and 232 of the first wire 23 and the third and fourth wires 241 and 242 of the second wire 24 are the cores 21, as shown in FIG. 2. ), The number of times preset by the experiment, for example, five times.

According to the experimental results, in the present embodiment, the first to fourth wires 231, 231, 241 and 242 of the wire 22 each have a maximum current capacity of about 30 A, so that the common mode filter 20 using the wire 22 is at least approximately. It has a current capacity of 50A or more.

The common mode filter 20 configured as described above is generated in the first and second wires 23 and 24 as current flows in opposite directions through the first and second wires 23 and 24 in a normal state. The magnetic fluxes cancel each other out.

On the other hand, when switching noise occurs in accordance with the switching operation of the switching unit 12, the current flowing through the first and second wires 23 and 24 changes rapidly.

Then, the impedance is rapidly increased because the magnetic flux generated in the first and second wires 23 and 24 wound in the same direction on the core 21 in accordance with the sudden current change is synthesized with each other.

The rapidly increased impedance blocks the transition and radiation of the switching noise from the switching unit 12 through the first and second wires 23 and 24.

Through the above process, the present invention removes the switching noise generated in the switching unit by using a common mode filter wound a predetermined number of times a pair of wires branched into two wires to the core of the ferrite material.

The scope of the present invention is not limited to the embodiments described above, but is defined by the claims, and various changes and modifications can be made by those skilled in the art within the scope of the claims. It is self evident.

In the above embodiment, the oil pump motor driving apparatus applied to the hybrid vehicle has been described, but the present invention is not necessarily limited thereto.

That is, the present invention can be applied to various electronic devices for controlling the driving of a three-phase BLDC motor using a switching element.

10: motor drive device for oil pump 11: power conversion circuit
12: switching unit 13: motor
14: control unit 15: switching noise removing device
20: common mode filter 21: core
22: wire 23, 24: first and second wire
231,231,241,242: first to fourth lines
25: cover

Claims (5)

In the switching noise removing device for removing the switching noise generated during the operation of distributing the current for driving the motor,
The switching noise removing device
Switching noise elimination device, characterized in that the common mode filter is installed in the power input terminal and composed of two choke coils merged into one. The method of claim 1, wherein the common mode filter
The core formed into the ring shape
A wire wound on the core a predetermined number of times,
The wire has first and second wires forming a return path and a return path,
And the first and second wires are respectively divided into two wires and wound around the core. The method of claim 2,
Switching noise removing device, characterized in that the first and second wires branched into the two wires are wound five times on the core. The method of claim 2,
Switching noise removing device, characterized in that the diameter of the first and second wires branched into the two wires is 2.3mm The method of claim 2, wherein the common mode filter
Further comprising a cover for shielding the wire wound core,
Switching noise removing device, characterized in that the cover is formed with the insertion hole is inserted into the wire.

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