CN110581011A

CN110581011A - Integrated EMC filter and power electronic device

Info

Publication number: CN110581011A
Application number: CN201810579969.7A
Authority: CN
Inventors: 罗新华; 苏辉
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-06-07
Filing date: 2018-06-07
Publication date: 2019-12-17

Abstract

The invention discloses an integrated EMC filter and power electronic device with current measurement function, the integrated EMC filter comprises a first magnetic core element and a second magnetic core element which are wound by an inductance winding, an air gap interval is arranged between the first magnetic core element and the second magnetic core element, and an induction magnetic field formed by the inductance winding penetrates through the air gap interval. According to one embodiment of the invention, a measuring unit for measuring the magnetic induction of the induced magnetic field is arranged in the air gap spacing, in order to obtain the output current of the integrated EMC filter as a function of the magnetic induction.

Description

Integrated EMC filter and power electronic device

Technical Field

The invention relates to an integrated EMC filter with a first and a second magnetic core element for being wound by an inductor winding, an air gap spacing being provided between the first and the second magnetic core element, through which air gap spacing an induced magnetic field formed by the inductor winding passes.

Background

In the current Power Electronic Unit (PEU) of an electric vehicle or a hybrid vehicle, the voltage depends on the actual load of the vehicle, the operation condition (whether the motor is in an electric state or a power generation state) and whether the motor is in a flux-weakening operation, etc., and the typical bus voltage fluctuation range is-30% to + 25% of the nominal value, so that the bus current needs to be monitored in real time under the condition that the vehicle condition frequently changes. In the prior art, the measurement is usually performed by providing a separate current measuring sensor.

In order to adapt to frequent changes of the working conditions of the automobile, a plurality of high-power electric energy change devices are needed. Their installation and use inevitably has serious electromagnetic interference. Therefore, it is necessary to install an EMC filter in the power electronic device. The electromagnetic compatibility noise is mainly composed of differential mode noise and common mode noise. In the circuit system, the differential mode noise is mainly suppressed by a filter network matched with a differential mode inductor, a differential mode capacitor and the like, and the common mode noise is mainly suppressed by a filter network matched with a common mode inductor, a Y capacitor and the like. A separate current measuring sensor for current measurement is then arranged downstream of the EMC filter.

Typically, individual current measurement sensors are expensive, thereby increasing the hardware cost of the power electronics. And the circuit of the power electronic device is more complicated due to the separate installation mode.

Disclosure of Invention

The invention aims to solve the technical problem of providing the EMC filter integrated with the current measuring function, thereby omitting a separate current measuring sensor, reducing the hardware cost and simplifying the system structure.

The technical problem is solved by an integrated EMC filter for power electronics of a hybrid or pure electric vehicle, which is capable of integrating the function of measuring the current. The integrated EMC filter has a first core element and a second core element wound by an inductive winding with an air gap spacing provided between the first core element and the second core. According to the technical scheme of the invention, a measuring unit for measuring the magnetic induction intensity of the induction magnetic field is arranged in the air gap interval, and the measuring unit can calculate the output current of the EMC filter according to the magnetic induction intensity. Thus, a separate current measuring sensor arranged downstream of the EMC filter can be replaced by the measuring unit, thereby reducing hardware costs and simplifying the system architecture.

According to a preferred embodiment of the invention, the first core element and the second core element are a pair of EE-type ferrite elements, i.e. the first core element and the second core element have an E-type shape and are made of ferrite. Furthermore, the E-shaped core element has two legs and a central leg, the two E-shaped core elements are arranged opposite each other, and an air gap is provided between the two opposite central legs, and a measuring unit is arranged in the air gap. Advantageously, the differential-mode inductance winding is wound on the side columns, the common-mode inductance winding is wound on the middle column, and the air gap interval can adjust the differential-mode inductance and the common-mode inductance, so that the adaptive measuring unit can be selected according to the size of the air gap interval. The smaller the air gap spacing, the greater the magnetic induction of the induced magnetic field therein, and therefore a measuring unit with a larger measuring range should be provided. Also preferably, other shapes of the core element are conceivable, such as U-shaped, open loop or C-shaped.

According to a further preferred embodiment of the invention, the measuring unit is a hall element. The hall element is low cost and readily available, thus enabling a significant reduction in hardware costs compared to using a separate current measuring sensor. It is further preferred that the EMC filter circuit according to the invention is arranged on a printed circuit board.

The object is also achieved according to the invention by a power electronics device for a motor vehicle, in particular for a hybrid vehicle or an electric vehicle, having an integrated EMC filter according to the above.

Drawings

Specific embodiments of the invention are schematically illustrated by the following figures. The attached drawings are as follows:

Figure 1 shows a perspective view of a core element of an EMC filter 1 according to the invention,

Figure 2 shows a top view of the core element shown in figure 1,

Fig. 3 shows an exemplary circuit diagram of an EMC filter according to the invention.

Detailed Description

Fig. 1 shows a partial component diagram of an EMC filter 1 according to the invention, which EMC filter 1 comprises a pair of EE cores, namely a first core 10 and a second core 11, which are situated opposite one another and each have two legs 12 and a central leg 13, a common-mode inductance winding being wound around the central leg of the two cores and a differential-mode inductance winding being wound around the legs of the two cores. An air gap 14 is provided between the two intermediate struts 13. Fig. 2 shows a plan view of the core element shown in fig. 1, in which the hall element 15 arranged between the center legs 13 of the two cores is visible. The hall element 15 derives the magnitude of the output current by measuring the magnetic induction between the two center posts 13.

Fig. 3 shows an exemplary circuit diagram of an EMC filter according to the present invention, Cx being a differential mode capacitance (X-capacitance), Cy being a common mode capacitance (Y-capacitance), T being a transformer, D being a diode. A differential mode inductance winding Ld1, Ld2 and Cx form differential mode filtering, and Ld1, Ld2 and Cy form a power filter. When there is differential mode interference output, Ld1 and Ld2 are equivalent to series inductance, and restrain differential mode signals. When the common mode interference passes through the common mode inductor, the magnetic fluxes generated in Lc1 and Lc2 are mutually enhanced, and the common mode interference is expressed as a great inductance, so that the common mode interference can be effectively suppressed.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1 EMC filter

10 first magnetic core

11 second magnetic core

12 side column

13 middle column

14 air gap interval

15 Hall element

Cx differential mode capacitance

Cy common mode capacitance

T-shaped transformer

d diode

Lc1, Lc2 common mode inductor winding

Ld1, Ld2 differential mode inductance winding

Claims

1. An integrated EMC filter having a first core element and a second core element wound with an inductor winding, an air gap spacing being provided between the first core element and the second core element, an induced magnetic field formed by the inductor winding passing through the air gap spacing,

characterized in that a measuring unit for measuring the magnetic induction of the induced magnetic field is arranged in the air gap spacing in order to obtain the output current of the integrated EMC filter from the magnetic induction.

2. Integrated emcfilter according to claim 1, characterised in that the measuring unit is a hall element.

3. Integrated emcfilter according to claim 1, characterized in that the first and second core elements have mutually opposing E-shapes.

4. integrated emcfilter according to claim 1, characterized in that the first and second core elements have mutually opposing C-or U-shapes.

5. Integrated EMC filter according to any of claims 1-4, wherein the first and second core elements are constituted by ferrite.

6. Integrated EMC filter according to claim 3, wherein the first and second core elements have two side legs on which the differential mode inductance winding is wound and a middle leg on which the common mode inductance winding is wound, respectively.

7. The integrated emcfilter of claim 6 wherein the air gap spacing is provided between the center leg of the first core element and the center leg of the second core element.

8. Integrated EMC filter according to claim 7, wherein the respective measuring unit is selected in dependence of the air gap spacing.

9. Integrated emcfilter according to claim 1, characterized in that the circuitry of the integrated emcfilter is arranged on a printed circuit board.

10. A power electronic device for a motor vehicle, characterized in that it comprises an integrated EMC filter according to any of claims 1 to 9.