Y-capacitor variable control structure for noise attenuation control

Abstract

The present invention discloses a Y-capacitor variable control structure for reducing common-mode noise of a power conversion system of an environmentally friendly vehicle. The structure cooperates with the vehicle's infotainment system to reduce the common-mode noise of the power conversion system. Specifically, the structure includes: a switching element connected to a high-voltage power supply connected to the vehicle and attenuating noise generated during PWM control; and a power conversion unit that receives common-mode noise generated from the power supply and controls the ON / OFF of the switching element to reduce the received common-mode noise.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0159459, filed on December 11, 2018, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to a Y-capacitor variable control structure for noise attenuation control. Background Art

[0004] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0005] Eco-friendly vehicles (xEVs) have a power conversion system that converts high-voltage power into desired power. In general, pulse width modulation (PWM) control is used to most efficiently convert AC-DC, DC-DC, and DC-AC power. Electromagnetic wave noise is generated as a side effect when PWM control is performed, and common mode noise, which is one type of electromagnetic wave noise generated, directly or indirectly has a great influence on the electromagnetic compatibility (EMC) performance of the vehicle.

[0006] In particular, common mode noise directly affects the performance of infotainment systems in vehicles. Multimedia and radio reception performance deteriorates due to noise, thus causing the overall marketability of the vehicle to deteriorate. Y-capacitors are considered to be an effective solution for reducing common mode noise, and almost all high voltage power conversion systems employ Y-capacitors.

[0007] In this regard, as a prior art, a Korean patent application with publication number 10-2014-0073715 (capacitor module for inverter of vehicle) discloses a capacitor module for inverter of vehicle, and the capacitor module for inverter of vehicle includes: i) a module housing; ii) a DC capacitor, which is arranged in the module housing and suppresses changes in voltage and current at a DC input terminal of the inverter; and iii) a CM filter, which is arranged in the module housing together with the DC capacitor and eliminates common mode noise.

[0008] However, it has been found that, in the related art, a capacitor is employed in a fixed state to eliminate PWM common mode noise generated from a high voltage power conversion system, and therefore, there is a limitation in that a noise attenuation band is restricted. Summary of the invention

[0009] The present disclosure provides a Y-capacitor variable control structure that can overcome the limitation caused by the limitation of the noise attenuation frequency band and perform variable control according to the operation mode of the infotainment system to improve the electromagnetic wave performance.

[0010] An exemplary form of the present disclosure provides a Y-capacitor variable control structure for noise attenuation control, which cooperates with the vehicle's infotainment system to reduce the common mode noise of the power conversion system. The structure includes: one or more switching elements connected to a high voltage power supply connected to the vehicle and configured to receive power from the high voltage power supply, wherein the switching element is configured to attenuate the noise generated during pulse width modulation (PWM) control; and a power conversion unit that receives the common mode noise generated from the high voltage power supply and controls the ON / OFF of the switching element to reduce the received common mode noise.

[0011] The switching element may be connected to a series Y-capacitor or a parallel Y-capacitor.

[0012] The power conversion unit may further include a switching element controller that changes ON / OFF of the switching element.

[0013] The controller may set a control mode of the switching element, and the control mode is set in advance in a frequency band to attenuate the common mode noise according to the frequency band of the common mode noise.

[0014] The power conversion portion may be provided between the switching element and the infotainment system, and may control the switching element based on an operation mode of the infotainment system.

[0015] According to the present disclosure configured as described above, it is possible to change (control) the attenuation band of the Y-capacitor filter and diversify the attenuation band of the filter according to the operation mode of the infotainment system.

[0016] According to the present disclosure, it is possible to improve electromagnetic wave performance (weak electric field reception performance) in all operating modes of an infotainment system, thereby providing excellent marketability (broadcast / media reception quality) and improving customer satisfaction compared to competitors.

[0017] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order that the present disclosure may be fully understood, various forms of the present disclosure given by way of example will now be described with reference to the accompanying drawings, in which:

[0019] Figure 1 is a view showing the structure of a Y-capacitor filter in the prior art;

[0020] Figure 2 is a view showing a Y-capacitor variable control structure applied to active high voltage;

[0021] Figure 3 is a diagram showing a state where various attenuation bands are achieved by variable control;

[0022] Figure 4 is a view showing a variable control structure of a Y-capacitor having a parallel structure; and

[0023] Figure 5 is a view showing a variable control structure for a Y-capacitor having a series structure.

[0024] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0025] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0026] From the following description, the purpose and effect of the present disclosure can be naturally understood, or the purpose and effect of the present disclosure can be made clearer, and the purpose and effect of the present disclosure are not limited to the following description. In addition, in the description of the present disclosure, when it is determined that the specific description of the known technology related to the present disclosure may unnecessarily obscure the subject matter of the present disclosure, the specific description will be omitted.

[0027] Figure 1 1 is a view showing the structure of a Y-capacitor filter 10 in the prior art. Figure 1 , the Y-capacitor filter 10 in the related art is used in a fixed state to eliminate the PWM common mode noise generated from the high voltage power conversion system, and therefore, has a limitation in that the noise attenuation band is limited.

[0028] Multimedia and radio reception bands for vehicle infotainment systems are gradually increasing to provide convenience to drivers, and therefore, there is a need to increase the attenuation band of the Y-capacitor filter 10. However, the capacity of a single Y-capacitor filter 10 in the prior art is difficult to meet the need.

[0029] Figure 2 is a diagram showing a Y-capacitor variable control structure 20 applied to active high voltage in one form of the present disclosure. Figure 2, the Y-capacitor variable control structure 20 may include: switching elements ① to ⑥, a power conversion unit 21, and a switching element controller 211 for controlling the switching elements. In one form, the switching element controller 211 may be separately provided in the power conversion unit 21. The constituent elements of the present disclosure may include a switching element (relay, FET, etc.) for changing the Y-capacitor filter and a switching element controller (internal structure of the power conversion unit 21), and an interface capable of collaborative control may be configured on the infotainment system 22 and the power conversion unit 21. In collaborative control, the switching element may be controlled by receiving information about the current operating mode (AM, FM, DMB, etc.).

[0030] The switching element can be connected to one or more high-voltage power supplies connected to the vehicle in the form of a Y-capacitor in series or parallel to receive power from the power supply and attenuate noise generated during PWM control. In addition, one or more switching elements can be connected in series or parallel.

[0031] One or more series or parallel capacitors in the form of Y-capacitors may be connected to the switching element, and the switching element controller 211 for controlling the switching element may control the switching element according to a control mode. The control mode for setting the ON / OFF of the switching element may be set in advance in a frequency band to attenuate the common mode noise according to the frequency band of the common mode noise.

[0032] For example, when the noise is in the A band, the attenuation band may be managed as the A′ band, and when the noise is in the B band, the attenuation band may be managed as the B′ band. The band is not a defined value but may be a value defined in the power conversion section 21 .

[0033] Return to reference Figure 2 , Figure 2 1 is a conceptual diagram showing a Y-capacitor variable control structure. The structure can be operated to select the capacity of the high-voltage Y-capacitor that is most suitable for the current operating mode (AM, FM, DMB, etc.) of the infotainment system 22 through cooperative control (CAN, LIN, etc.) between the infotainment system 22 and the high-voltage power conversion unit 21 (inverter / converter) such as an antenna, multimedia device, and radio device.

[0034] The capacitance of the high voltage Y-capacitor can be selected by controlling the switching element (relay, FET, etc.), and the capacitor can be changed to several cases according to the number of Y-capacitor filters, the position of the switching element and the control method.

[0035] In the case where the Y-capacitor filters A and B and the switching elements ① to ⑥ are variably configured according to the exemplary form of the present disclosure, a total of four combinations (Y-capacitor A, Y-capacitor B, Y-capacitor A and Y-capacitor B in series, and Y-capacitor A and Y-capacitor B in parallel) of the capacity values ​​of the Y-capacitor can be selected. Each of the capacities of the four combined Y-capacitors can be designed to be an optimal value for each operating mode of the infotainment system 22, and the optimal EMC performance can be achieved for each operating mode.

[0036] A variable control structure for the Y-capacitor can be actively implemented by using two types of Y-capacitors A and Y-capacitors B and utilizing six switching elements ① to ⑥.

[0037] [Table 1]

[0038]

[0039] The type of Y-capacitor and the number of switching elements may be increased as the frequency band of noise that needs to be attenuated increases in the infotainment system 22. An increase in the capacity of the Y-capacitor (parallel connection structure) may achieve additional attenuation in a relatively low frequency band, while a decrease in the capacity of the Y-capacitor (series connection structure) may achieve additional attenuation in a relatively high frequency band.

[0040] The power conversion unit 21 can control the ON / OFF of the switching element to receive the common mode noise generated from the power supply and reduce the received common mode noise. In the case where the power conversion unit 21 includes the switching element controller 211, the switching element controller 211 can change the ON / OFF of the switching element. The power conversion unit 21 can control the switching element between the switching element and the infotainment system 22 according to the operation mode of the infotainment system 22.

[0041] Figure 3 2 is a diagram showing a state in which various attenuation bands are realized by variable control according to an exemplary form of the present disclosure. Figure 3 , compared with a single attenuation band of a fixed Y-capacitor in the prior art, various attenuation bands can be achieved according to the control mode of the switching element.

[0042] The attenuation band can be converted to the attenuation band of the filter optimized for the current operation mode by receiving information about the operation mode of the infotainment system 22 and controlling the switching element. In the case of increasing the operation mode of the infotainment system 22 or increasing the frequency band of the noise that needs to be attenuated, the Y-capacitor and the switching element can be additionally applied to additionally realize the attenuation band of the filter.

[0043] Figure 4is a view showing a Y-capacitor variable control structure having a parallel structure according to an exemplary form of the present disclosure, Figure 5 is a view showing a variable control structure for a Y-capacitor having a series structure according to an exemplary form of the present disclosure. Figure 4 and Figure 5 Examples of various modes of the switching element are shown, and the structure is not limited to these examples. Figure 4 and Figure 5 Configuration and Figure 2 The above configuration is the same, so reference will be omitted Figure 4 and Figure 5 Description.

[0044] Although the present disclosure has been described in detail above with reference to representative exemplary forms, those skilled in the art will appreciate that various modifications may be made to the exemplary forms without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described exemplary forms.

Claims

1. A Y-capacitor variable control structure for noise attenuation control, the structure cooperating with a vehicle's infotainment system to reduce common-mode noise in a power conversion system, the structure include: at least one switching element connected to a high voltage power source coupled to the vehicle and receiving power from the high voltage power source, the at least one switching element attenuating noise generated during pulse width modulation control (PWM control); as well as a power conversion unit that receives the common mode noise generated from the high voltage power supply and controls the on / off of the at least one switching element to reduce the received common mode noise, wherein the power conversion unit is provided between the at least one switching element and the infotainment system, and controls the at least one switching element based on an operation mode of the infotainment system, The variable control structure operates to select the capacity of the high-voltage Y-capacitor most suitable for a current operation mode of the infotainment system through cooperative control between the infotainment system and the power conversion portion.

2. The structure according to claim 1, in, The at least one switching element is connected to a series Y-capacitor or a parallel Y-capacitor.

3. The structure according to claim 1, in, The power conversion unit further comprises: A switching element controller changes the on / off state of the at least one switching element.

4. The structure according to claim 3, in, The controller sets a control mode of the at least one switching element, and The control mode is set in advance in a frequency band to attenuate the common mode noise according to the frequency band of the common mode noise.

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