DESC:FIELD OF THE INVENTION
[0001] The present invention generally relates to arrangement of various power electronics components in an electric motor and its related applications. More specifically, it relates to the optimal positioning or arrangement of power electronic components on a printed circuit board (PCB) of a motor resulting in improved thermal conductivity and minimized switching losses.

BACKGROUND
[0002] In general, power electronics components used in various electric motor related applications are typically arranged on a printed circuit board (PCB) in a way that minimizes the inductance and capacitance of the interconnections and maximizes thermal performance by providing adequate spacing and thermal vias.

[0003] Each power electronics components/devices such as MOSFET, phase leads, gate driver, current sensing resistor etc., should be properly placed in a circuit for its effective operation to drive electric motors.

[0004] Particularly, gate driver should be placed at a proper distance respective to the MOSFET to avoid ringing effects, reduce EMI/EMC issues as well as ON/OFF losses. Also, placing the shunt resistor away from the MOSFET may lead to noise absorption. Further, in existing circuit arrangements, the phase leads are arranged in a sequential or in a daisy chain manner on the PCB.

[0005] The present invention intends to propose such an optimal placement on PCBs for these power electronic components to meet the high current requirements, improve thermal conductivity, reduce EMI (Electromagnetic Interference) and ensure EMC (Electromagnetic Compatibility), and providing copper isolation between phase voltage and DC bus.

OBJECTIVES OF THE INVENTION
[0006] The primary objective of the present invention is to provide an arrangement of the various power electronics components comprising mainly of MOSFETS, gate driver, phase leads, shunt resistor and on-axis sensor positioned on a printed circuit board (PCB) utilized in an electric motor.

[0007] Another objective of the present invention is to regulate the placement of MOSFETs with respect to the phase holes, to meet copper isolation requirements.

[0008] Yet another objective of the present invention is to provide an adequate plane or layout for the MOSFETs enabling an increase reliability in functionality.

[0009] Even another objective of the present invention is to enhance better thermal conductivity, minimize switching losses, prevent ringing effects, reduce EMI/EMC issues and meet high current requirements in the power electronic components.

SUMMARY
[0010] The following summary is provided to facilitate a clear understanding of the new features in the disclosed embodiment, and it is not intended to be a full, detailed description. A detailed description of all the aspects of the disclosed invention can be understood by reviewing the full specification, the drawing, and the claims and the abstract, as a whole.

[0011] In order to achieve the aforementioned objectives, the present invention discloses an arrangement of various power electronics components/devices utilized in a printed circuit board (PCB) for electric motor related applications. This arrangement aims to meet high current requirements, reduce EMI/EMC issues and switching losses, as well as enhance thermal conductivity.

[0012] According to an aspect of the present invention, a gate driver is placed in symmetrical manner with equal distance from MOSFET in order to achieve shortest control trace length running towards MOSFET and to avoid ringing effect thereby reducing EMI/EMC issues and reduce ON/OFF losses. Also, MOSFET is placed closer to phase hole meets high current requirement within available room/space. Shunt resistor is placed very near to MOSFET to improve EMI/ EMC issues and improve noise absorption.

[0013] In accordance with an aspect of the preferred embodiment of the present invention, the phase leads are positioned in triangle mode/configuration (but not limited to it) for better phase split isolation, to achieve the best phase winding coupling to the PCB with lesser length from motor housing exit (also reduces resistance). Also, the placement of MOSFET have better heat sink butting with motor housing which provides better thermal conductivity.

[0014] Furthermore, another aspect of the present invention includes MOSFET and Phase hole placement routing planning in order to meet copper isolation requirements between the followings: (i) Phase to Phase (ii) MOSFET –DC Bus Voltage to Phase voltage (iii) Gate driver section to Phase (iv) On Axis and vicinity section.

[0015] In the present invention, the placement/arrangement of various power electronics components including gate driver and on-axis sensors, shunt resistors, MOSFETs, phase holes and current sensing resistor are discussed, but not limited to it.

BRIEF DESCRIPTION OF THE DRAWINGS:
[0016] The present invention will be better understood fully from the detailed description that is given herein below with reference to the accompanying drawings of the preferred embodiments of the present invention, which, however, should not be deemed to be a limitation to the invention to the specific embodiments, but, are for the purpose of explanation and understanding only.

[0017] FIG. 1 illustrates the placement of various power electronics components in outline view according to a preferred embodiment of the present invention.
[0018] FIG. 2 shows the comprehensive representation on the placement of various power electronics components in PCB according to the preferred embodiment of the present invention.

[0019] FIG. 3 illustrates a schematic representation of the placement of various power electronic components at the different phases (Blue, Red, Yellow).

[0020] FIG. 4(a) shows the symmetric placement of MOSFET and gate driver.

[0021] FIG.4(b) shows the placement of shunt resistor and gate driver.

[0022] FIG. 5 shows the proposed phase lead arrangement in triangle mode configuration according to present invention.

[0023] It should be noted that the figures are not drawn to scale. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.

LIST OF REFERENCES

10 - PCB
12 - MOSFET
14 - Gate driver
16 - Phase holes
18 - Shunt resistor
20 - On-axis sensor
22 - Phases leads

DETAILED DESCRIPTION OF THE INVENTION:

[0024] The following is a description of the present disclosure depicted in the accompanying drawings. However, it may be understood by a person having ordinary skill in the art that the present subject matter may be practised without these specific details. In other instances, well-known methods, procedures, and/or components regarding the said method have not been described in detail so as not to obscure the subject matter of the disclosure. The subject matter of the disclosure will be more clearly understood from the following description of the embodiments thereof, given by way of example only with reference to the accompanying drawings, which are not drawn to scale.

[0025] The described embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the described embodiments are not to be limited to the particular forms or methods disclosed, but to the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives.

[0026] The term “PCB” refers to Printed Circuit Board, that helps manage and control various electrical and electronic systems within the electric vehicle (EV). The term “EMI/EMC” refers to Electromagnetic Interference and Electromagnetic Compatibility, respectively. Both EMI and EMC are related to the unintended generation, propagation, or reception of electromagnetic energy that can cause disturbances or degradation in the performance of electronic equipment. The term “MOSFET” stands for Metal-Oxide-Semiconductor Field-Effect Transistor, which is a type of transistor used in electric vehicles (EVs) and many other electronic devices. “HS B source, HS R source, and HS Y source” refer to the High-Side Bootstrap sources for the blue, red, and yellow phases, respectively, in the power electronics system. These sources are crucial for providing the necessary voltage to drive the high-side MOSFETs or switches in the motor control circuitry.

[0027] The term "ringing effect" refers to an undesirable oscillation or overshoot that occurs in the voltage or current waveform during switching transitions, particularly in switching devices like MOSFETs, IGBTs, or diodes. This ringing effect can lead to several issues, including increased electromagnetic interference (EMI), voltage spikes, and potential damage to the components or the circuit. A “power electronic component” is a type of electronic device or circuit that is designed to control and convert electrical power. These components are crucial in systems where electrical energy needs to be efficiently converted, controlled, and managed, such as in electric vehicles, renewable energy systems, industrial drives, and consumer electronics. The term “positioning” and “arrangement” have been used interchangeably here.

[0028] The present invention therefore, discloses an optimum arrangement/ positioning of various power electronics components/devices such as MOSFETs, phase lead studs, shunt resistors in a PCB used in electric motor related applications. This arrangement aims to meet high current requirements, minimize EMI/EMC issues, reduce switching losses and enhance thermal conductivity.

[0029] Referring to FIG.1 and Fig.2, the outline view illustrates the positioning of various power electronics components in the PCB (10) according to a preferred embodiment of the present invention. In particular, the positioning of the six MOSFETs (12) is highlighted, each MOSFET being numbered and outlined. Fig.1 depicts that the six MOSFETS (12) are positioned along the periphery of the PCB (Printed Circuit Board) (10). Additionally, the six MOSFETs (12) are arranged symmetrically: MOSFET-1, MOSFET-3 and MOSFET-5 are situated on one side of the PCB, whereas MOSFET-2, MOSFET-4 and MOSFET-6 are symmetrically positioned, on the opposite side of the PCB (10), as seen in Fig.1.

[0030] Referring back to Fig.1, the gate driver (14) is symmetrically located on the PCB (10) ensuring consistent distances between MOSFET 1 and 2, MOSFET 3 and 4 and MOSFET 5 and 6 to the gate driver. Furthermore, the phase holes (16) for the different phases leads (22) of blue, red, yellow phases are positioned very close to the MOSFETs (12), as illustrated in Fig.1. Likewise, the shunt resistors (18) are positioned in close proximity to the MOSFETs (12), and the on-axis sensor (20) is located in the vicinity of the gate driver (14), as depicted in Fig.1.

[0031] FIG. 2 depicts a more comprehensive representation on the arrangement of various power electronics components in the PCB (10) of a motor according to a preferred embodiment of the present invention. FIG. 3 herein illustrates a schematic representation on the arrangement of the power electronic components, like MOSFETs (12), gate driver (14), shunt resistors (18) and on-axis sensor (20) at the different phases of Blue (B), Red (R) and Yellow (Y).

[0032] According to a preferred embodiment of the present invention, the MOSFETs (12), phase leads (22), shunt resistors (18) are arranged in such a way that high current of these devices do not interfere with the centrally positioned on-axis sensor (20), which senses the rotation of the rotor. Despite the sensitivity of the sensor (20) to nearby noises generated by the power electronic module, this arrangement prevents much disturbances.

[0033] Generally, the sensors are placed in the central axis to detect the rotation of the motor rotor. However, the other power electronic components have to be placed away from the sensor to avoid a ringing effect or disturbing the sensor function. In the preferred embodiment of the present invention, the placement of the MOSFETs and other power electronic components is designed to ensure that that the sensor will not get affected with nearby positioning of these other power electronic components does not affect the sensor.

[0034] Referring to FIG. 4(a) and as discussed earlier, the gate driver (14) is symmetrically positioned on the PCB (10), maintaining consistent distances between the 6 MOSFETs (12) and the gate driver (14). This arrangement ensures consistent and symmetrical distances from the MOSFETs (12), achieving the shortest control trace length running towards MOSFETs (12) from the gate driver (14). This positioning aims to prevent ringing effects, reducing EMI/EMC issues and minimizing ON/OFF losses. Additionally, the MOSFETs (12) are placed closer to the phase holes (16) in order to meet high current requirement within the available space. FIG. 4(b) depicts the strategic placement of the shunt resistors (18) relative to the gate drive (14) and MOSFETs (12). It is illustrated in Fig.4(b), that the shunt resistors (18) are placed in close proximity to the MOSFETs (12) and/or gate driver (14) so as to reduce EMI/EMC issues and to avoid noise absorption. A distance ranging from a minimum of 1.5mm to a maximum of 3mm between the shunt resistor and the MOSFET and/or gate driver is recommended.

[0035] Referring to Fig.5, the phase leads (22) are positioned in a triangular mode/configuration on the PCB (10) in accordance with the preferred embodiment of the present invention. While this triangular layout is beneficial, it is not the only arrangement possible. The triangular arrangement of the phase leads (22) ensures enhanced phase split isolation, and helps to achieve an optimal phase winding coupling to the PCB (10), wherein it is designed with lesser lengths from the motor housing exit (not shown here) which also minimizes resistance. Additionally, the effective and planned placement of MOSFETs (12) on the PCB (10) ensures better heat sink butting with the motor housing thereby improving the thermal conductivity of the MOSFETs (12).

[0036] Furthermore, the MOSFETs and the phase hole placement routings are strategically planned to meet the following copper isolation requirements: (i) Phase to Phase isolation (ii) MOSFET – DC Bus Voltage to Phase voltage isolation for improved operational performance (iii) Gate driver section to phase isolation (iv) isolation between the On Axis section and its vicinity.

Experimental Analysis
[0037] Table 1 discloses an experimental analysis conducted on a PCB comparing the effects of optimal and non-optimal positioning of power electronics.
Table 1:

[0038] The results of Table 1 showed that without optimal positioning, there was a significant increase in EMI/EMC interference. In contrast, when the power electronics were optimally positioned, a reduction in EMC/EMI interference was observed. Furthermore, without optimal positioning of the power electronics, a ringing effect at 5MHz was detected, whereas with optimal positioning, the ringing effect reduced to 1.2MHz.

[0039] Moreover, optimally positioning the various power electronics components on the PCB (10) provides several other advantages leading to a balanced MOSFET drive and accurate base current sensing. Specifically, placing MOSFET at the bottom of the PCB (10) enhances thermal conductivity with the housing, and the adequate plane provided for the MOSFETs increase reliability and functionality.

[0040] Therefore, the present invention encompasses various power electronics components such as gate drivers, on-axis sensors, shunt resistors, MOSFETs and phase leads and current sensing resistors, among others, but not limited to it.

[0041] The invention is not limited only to the embodiments described above and shown in the drawings, which primarily have an illustrative and exemplifying purpose. This patent application is intended to cover all adjustments and variants of the preferred embodiments described herein; thus, the present invention is defined by the wording of the appended claims and the equivalents thereof. Thus, the equipment may be modified in all kinds of ways within the scope of the appended claims.
,CLAIMS:I/WE CLAIM:

1. A positioning for power electronic components for a printed circuit board (PCB) (10) of an electric motor, comprising:
a plurality of MOSFETs (12);
a gate driver (14) positioned equidistant from the MOSFETs (12);
the MOSFETs placed proximately to phase holes (16) corresponding to blue, red and yellow phases;
a plurality of shunt resistors (18) located adjacent to MOSFETs and / gate driver; and
an on-axis sensor (20);
wherein the positioning of the power electronic components on the printed circuit board (PCB) (10) is configured to optimize the performance of the electric motor.

2. The positioning as claimed in claim 1, wherein the plurality of shunt resistors (18) are placed at a distance ranging from 1mm to 5mm to the MOSFETs (12) or the gate driver (14).

3. The positioning as claimed in claim1 wherein the gate driver is positioned on the PCB (10) so as to achieve minimal control trace length relative to the MOSFETs.

4. The positioning as claimed in claim 1 wherein the said MOSFETs (12) are arranged on the PCB (10), in a symmetrical layout.

5. The positioning as claimed in claim 1, wherein phase leads (22) are arranged in a triangular configuration on the PCB (10).

6. The positioning as claimed in claim 1, wherein the high currents flowing through said MOSFET, phase leads, and shunt resistors are configured to avoid interference with the on-axis sensor (20).

7. The positioning as claimed in claim 1, wherein the positioning of the power electronic components is route planned to meet copper isolation requirements, comprising:

the MOSFETs (12) and phase holes (16) routed between phase-to-phase connections;
the MOSFETs (12) routed between MOSFET – DC Bus Voltage and Phase voltage connections;
gate driver sections routed between the gate driver (14) and respective phase connections; and
the on-axis (20) and vicinity sections are routed between the On Axis section and its surrounding components.

8. The positioning as claimed in claim 1 wherein a reduction in electromagnetic compatibility (EMC) and electromagnetic interference (EMI) is achieved.