Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M1/00—Details of apparatus for conversion
  • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/003—Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M1/00—Details of apparatus for conversion
  • H02M1/14—Arrangements for reducing ripples from dc input or output
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
  • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters

Definitions

• the description relates to the field of power modules for electric motors.
• EMC Electro Magnetic Compatibility
• a power module sometimes includes an electromagnetic shield, reducing unwanted electromagnetic emissions from the power module.
• this electromagnetic shield is delicate. It often leads to complex mechatronic issues that are difficult to model. Mass recovery, ie the connection of the mass of the power module to the electromagnetic shielding, often gives rise to the occurrence of an undesirable resonant frequency, large enough to exceed the template defined by a standard applicable.
• the invention aims to improve the situation.
• One aspect of the invention relates to an electronic device comprising:
• an electronic circuit adapted to be connected to an electromagnetic shield via a ground resumption as well as to be connected between a source of electrical voltage and an electric motor control circuit, the electronic circuit comprising: a first electrical connection for connecting a first output terminal of the electrical voltage source to a first power supply terminal of the electric motor control circuit,
• An RC circuit comprising a resistor and at least one capacitor, connected in series, a terminal of the RC circuit being connected to the first electrical connection, the other terminal of the RC circuit being connected to the second electrical connection.
• Such an electronic device is advantageous in that it makes it possible to attenuate in particular a parasitic resonance resulting from the mass recovery, and this in a manner sufficient to respect the templates imposed by the applicable standards.
• One aspect of the invention relates to an electronic device comprising said electric motor control circuit, said electric motor control circuit comprising a differential filter, said differential filter being connected to the first and second electrical links.
• One aspect of the invention relates to an electronic device comprising said electromagnetic shield.
• One aspect of the invention relates to an electronic device wherein said electromagnetic shield is a heat sink or an additional metal piece (for example disposed between the outer rotor and the inner stator).
• One aspect of the invention relates to an electronic device in which the RC circuit comprises a single resistor.
• One aspect of the invention relates to an electronic device in which the RC circuit comprises a single capacitor.
• One aspect of the invention relates to an electronic device in which the RC circuit comprises two capacitors.
• One aspect of the invention relates to an electronic device in which the two capacitors are placed on either side of the resistor.
• One aspect of the invention relates to an electronic device in which both capacitors are placed on the same side of the resistor.
• One aspect of the invention relates to an electronic device comprising an input connector for connecting the electronic circuit to the voltage source, wherein the RC circuit is implanted under said input connector.
• FIG. 1 shows a power module according to the state of the art
• FIG. 2 represents a power module according to one embodiment of the invention
• FIGS. 3A, 3B, 3C and 3D represent four different versions of an RC filter according to embodiments of the invention.
• FIG. 4A represents the integration of an RC filter according to one embodiment of the invention on a printed circuit
• FIG. 4B is an enlarged view of the RC filter of FIG. 4A;
• FIG. 5A contains two curves, one illustrating the spurious emissions measured on a power module according to the state of the art in the FM band, the other illustrating the spurious emissions measured on a power module according to a mode. embodiment of the invention in the same FM band;
• FIG. 5B contains two curves, one illustrating the parasitic emissions measured on a power module comprising a filter, but no damping resistor, the other illustrating the parasitic emissions measured on a power module according to a mode of embodiment of the invention;
• FIGS. 6A, 6B and 6C each show a curve illustrating a simulation of the attenuation of an RC filter according to the invention, as a function of frequency. The curves are distinguished by the value of the resistance of the RC filter.
• Figure 1 shows a power module according to the state of the art. This can be connected to a battery via two terminals + Vbat (reference 1) and -Vbat (reference 2).
• the power module comprises a driver circuit 3 for driving the electric motor.
• the module comprises a filter PI, comprising two capacitors C1 and C2 (references 4 and 5 respectively) and a coil L1 (reference 6).
• the PI filter is insufficient to filter out any noise generated by the power module.
• the two capacitors C1 and C2 are in this case polarized capacitors.
• FIG. 2 represents a power module according to one embodiment of the invention.
• the control circuit is not represented.
• the IP filter of the state of the art is improved by adding an L2 coil (reference 7).
• This additional coil is particularly advantageous in that it makes it possible to reduce the common-mode current, in particular for frequencies that are greater than 76 MHz. This improvement is optional and a conventional PI filter could also be used.
• an RC circuit (called “snubber") is placed upstream of the PI filter (between this PI filter and the voltage source).
• This RC circuit comprises a resistor R1 (reference 8) and two capacitors C3 and C4 (references 9 and 10 respectively). These two capacitors C3 and C4 (in this case unpolarized) can be seen as a single capacitor C34.
• This RC circuit makes it possible to attenuate a resonance resulting from a mass recovery of the power module with an electromagnetic shielding.
• FIGS. 3A, 3B, 3C and 3D represent four different versions of an RC filter (of the "snubber" type, also called damping filter) according to embodiments of the invention. These versions can replace the RC filter composed of the resistor R1 and capacitors C3 and C4 of Figure 2.
• FIG. 3A thus shows a filter RC comprising a resistor R4 (reference 1 1) placed in series between two capacitors C7 and C9 of 220 nF each (references 12 and 13).
• the terminals of the capacitors C7 and C9 not connected to the resistor R4 are respectively connected to a first electrical connection connectable to the terminal + Vbat of a battery and to a second electrical connection connectable to the terminal -Vbat of a battery.
• FIG. 3B shows a filter RC comprising a resistor R2 (reference 14) placed in series with two capacitors C5 and C8 of 220 nF each (references 15 and 16).
• a terminal of the resistor R2 is connected to a first electrical connection connectable to the terminal + Vbat of a battery, while the second terminal of the resistor R2 is connected to a terminal of the capacitor C5.
• the other terminal of the capacitor C5 is connected to a terminal of the capacitor C8.
• the other terminal of the capacitor C8 is connected to a second electrical connection connectable to the terminal -Vbat of the battery.
• FIG. 3C shows a filter RC comprising a resistor R3 (reference 17) placed in series with a capacitor C6 of 100 nF (reference 18).
• the terminal of the resistor R3 not connected to the capacitor C6 is connected to a first electrical connection connectable to the terminal + Vbat of a battery.
• the terminal of the capacitor C6 not connected to the resistor R3 is connected to a second electrical connection connectable to the terminal -Vbat of the battery.
• Figure 3D shows an RC filter comprising an R5 resistor (Reference 19) placed in series with a capacitor C10 of 100 nF (reference 20).
• the terminal of the capacitor C10 not connected to the resistor R5 is connected to a first electrical connection connectable to the terminal + Vbat of a battery.
• the terminal of the resistor R5 not connected to the capacitor C10 is connected to a second electrical connection connectable to the terminal -Vbat of the battery.
• FIG. 4A represents the integration of an RC filter according to an embodiment of the invention on a printed circuit.
• the printed circuit of the electronic device according to one embodiment of the invention comprises a connector 21, arranged to establish an electrical connection with a voltage source such as a motor vehicle battery.
• the + Vbat and -Vbat connections are represented by the references 1 and 2.
• the RC filter is integrated under the connector.
• the RC filter is composed of a damping resistor R52 (reference 22), followed, in series, by two capacitors C46 and C45 (references 23 and 24).
• Figure 4B shows an enlarged view of the RC filter of Figure 4A.
• Figure 5A shows two curves.
• Curve 25 illustrates the parasitic emissions measured on a power module according to the state of the art (devoid of RC filter according to the invention, but comprising a traditional IP filter modified by adding a coil corresponding to the coil 7 in Figure 2).
• Curve 26 illustrates the spurious emissions measured on a power module according to one embodiment of the invention, comprising a traditional PI filter modified by adding a coil corresponding to the coil 7 in FIG. 2 as well as a filter RC according to the invention, the RC filter comprising a resistance of 100 m ⁇ and two capacitors of 220 nF each.
• the measurements are made in the FM band, more precisely in a slightly larger range, from 76 MHz to 108 MHz.
• the measurements made are QPEAK-type measurements (that is to say, measurements intended to detect local maxima (the maximum over the 120kHz range considered). and no, for example, local averages (which would each correspond to the average of the values over the 120kHz range considered).
• the measurements are made in RSIL-. This means that measurements are made at a line impedance stabilization network (RSIL) connected to the battery terminal -Vbat.
• RSIL line impedance stabilization network
• the curve for the power module according to the state of the art is above the standard BMW_EC_Q (corresponding to the template represented by a dotted line 27) over the entire range from 76 MHz to approximately 105 MHz.
• the curve falls below the template only between about 105 MHz and 108 MHz.
• the emission levels therefore exceed the thresholds set by the standards for most of the spectrum of the FM band.
• the curve for the power module according to the invention is systematically below the jig, and therefore complies with the BMW_EC_Q standard.
• the values measured by the analyzer at the level of the two cursors make it possible to observe more precisely -7.01 db ⁇ V between the two cursors, thus about 7 db ⁇ V gain at the frequency considered (which in this case is equal to 84.64 MHz).
• the value recorded at cursor 1 is 21.16 db ⁇ V at 84.64 MHz.
• the -80 kHz indication corresponds to the time offset between the two sliders (negligible offset from 85MHz). The two sliders can therefore be considered as being both about 85 MHz.
• Figure 5B shows two curves.
• Curve 28 illustrates the spurious emissions measured on a power module equipped with a filter (formed by a capacity of 100 nF), but without damping resistor.
• Curve 29 illustrates the spurious emissions measured on a power module with an RC filter comprising a damping resistor of 100m ⁇ and a capacitor of 100nF.
• Curve 5B makes it possible to show the effect (and more precisely the interest) of the damping resistor. In both cases (curve 28 and curve 29) a filter is added. The effect of the filter is highlighted by comparison with curve 5A (with or without filter).
• the measurements are made in a very wide band including the AM band and the FM band, more precisely in the range of 150 kHz to 108 MHz. These measurements are performed with an RBW of 9 kHz between 150 kHz and 76 MHz and with a RBW of 120 kHz between 76 MHz and 108 MHz.
• the measurements made are AV-type measurements ("average” meaning "averages"), that is to say, measurements aimed at detecting local averages (the average of the values in the range). of 120kHz considered).
• the measurements are made in RSIL +. This means that measurements are made at a line impedance stabilization network connected to the + Vbat terminal of the battery.
• FIGS. 6A, 6B and 6C each show a curve illustrating a simulation of the attenuation of an RC filter according to the invention, as a function of frequency.
• the frequency range considered is the 10kHz - 100MHz range.
• the curves are distinguished by the value of the resistance of the RC filter.
• the curve of FIG. 6A corresponds to an electronic device according to the invention in which the resistance of the filter RC is suppressed. There is then a peak at 3.7619MHz which rises to -29.90164dB.
• a 100m ⁇ resistor within the RC filter FIG. 6B
• the peak at 3.6667MHz
• the peak appears at 3.908 MHz, and only reaches - 46.53938 dB.
• a resistance of 1 ⁇ gives good results. Any value between 250m ⁇ and 1 ⁇ is particularly appropriate, values coming out of this range are also possible.
• an electronic device comprises an electronic circuit adapted to be connected to an electromagnetic shield via a mass recovery.
• the electronic circuit is adapted to be connected between a voltage source and an electric motor control circuit.
• the electronic device is for example a power module of the electric motor.
• the electric motor is for example a brushless electric motor.
• Brushless electric motors can be used, for example, in motor vehicle interior fans. These are for example HVAC fans (acronym from the English term "heating, ventilation and air conditioning") that is to say, fans designed to ensure a comfortable passenger compartment for the vehicle via its heating, its ventilation or air conditioning.
• the electronic circuit includes a first electrical connection for connecting a first output terminal of the electrical voltage source to a first power supply terminal of the electric motor control circuit.
• This first electrical connection is for example a connection connectable to a first terminal + Vbat of a battery.
• the first one Terminal + Vbat typically delivers + 12V, continuously, compared to a second rated terminal -Vbat battery.
• terminal is generally meant (and throughout the description) any means establishing an electrical connection (by welding, etc.).
• terminal in no way implies the possibility of disconnection, although a terminal allowing a mechanical and electrical disconnection is possible.
• the electronic circuit includes a second electrical connection for connecting a second output terminal of the voltage source to a second power supply terminal of the electric motor control circuit.
• This second electrical connection is for example a connection connectable to the aforementioned -Vbat terminal of the battery (which is typically connected to the mass of the motor vehicle in which the battery is installed).
• This resonant frequency is related in particular to the fact that the electronic circuit chops a signal at a high enough frequency to drive the electric motor.
• the RC circuit has a function quite different from that RC circuits that are sometimes found at the terminals of the electric motor, it operates in different frequency bands.
• control circuit is conventional and conventionally comprises a PI filter (references 4, 5, 6 in FIG. 1) as well as a motor control circuit (reference 3 in FIG. 1). ).
• control circuit comprises an additional coil (reference 7 in FIG. 2).
• the electronic circuit comprises an RC circuit comprising a resistor and at least one capacitor connected in series. One terminal of the RC circuit is connected to the first electrical connection, the other terminal of the RC circuit being connected to the second electrical connection.
• the RC circuit is thus provided to be mounted in parallel with the electric motor control circuit as well as with the power supply that constitutes the voltage source. The RC circuit reduces the frequency of resonance created when the electronic circuit is electrically connected to the electromagnetic shield via mass recovery.
• this resonant frequency appears at a frequency of approximately 4 MHz.
• a resistance of at least 100 m ⁇ (a value of 250 m ⁇ or even 1 ⁇ being entirely appropriate), and a capacitor of about NF (or a set of capacitors whose collective capacitance is about 1 nf, for example two capacitors of 220 nF in series).
• an electronic device comprises said electric motor control circuit.
• Said electric motor control circuit comprises at its input (intended to be connected to the voltage source) a differential filter, also called a power filter.
• This differential filter is connected to the first and second electrical connections.
• the differential filter is for example a PI filter, comprising two capacitors and a coil.
• a first capacitor of the PI filter is placed in parallel with the electronic circuit and in parallel with the voltage source when connected. It is connected by a terminal to the first electrical connection and by its second terminal to the second electrical connection.
• the second capacitor of the PI filter is connected by one of its two terminals to one of the two terminals of the coil as well as to a terminal of the remainder of the control circuit (ie that part of the control circuit located in downstream of the PI filter with respect to the voltage source).
• the second capacitor of the PI filter is connected by its second terminal to the second electrical connection as well as to the other terminal of the rest of the control circuit.
• the coil is connected by its other terminal to the first electrical connection.
• the electronic device serves to attenuate a resonance that can be created by the capacitor (s) of the RC circuit and the first capacitor of the PI filter (which is connected in parallel with the RC filter).
• the electronic device comprises said electromagnetic shielding.
• the latter can for example be connected to the electronic circuit via a ring-shaped connection, acting as a mass recovery.
• a metal ring with an inside diameter of about 8 mm and an outside diameter of about 1 cm gives a relatively good mass recovery.
• a good mass recovery must have a low resistance (for example of the order of a few mQ maximum), which facilitates a large contact area between the electromagnetic shielding and the electronic circuit.
• the electromagnetic shielding of an electronic device is a heat sink. It may be a metal radiator to dissipate the thermal energy released by the device at the same time it operates a shielding function.
• the RC circuit of an electronic device comprises a single resistor.
• This resistance preferably takes a value between 10Om ⁇ and 1 ⁇ . Different values are also possible.
• the RC circuit of an electronic device comprises a single capacitor. This is simpler, and a little less expensive. Resistance can be placed in front of or behind the capacitor (both alternatives work).
• the RC circuit of an electronic device comprises two capacitors (only two, according to one possible implementation).
• Capacitors are, for example, ceramic capacitors.
• the two capacitors are placed at 90 ° with respect to each other (as illustrated in FIG. 4B). This greatly reduces the probability of short-circuiting the two capacitors (for example in the case of twisting or deformation of the printed circuit).
• the extra cost associated with a second capacitor is relatively minor, so it is better to provide two capacitors rather than one. With two capacitors of 220nF, each in series, we obtain the equivalent of a capacitor of 1 10nF. This is an order of magnitude quite appropriate.
• the two capacitors of an electronic device according to the seventh embodiment are placed on either side of the resistor.
• the two capacitors of an electronic device according to the seventh embodiment are both placed on the same side of the resistor.
• the RC circuit is then implanted under said input connector, it is thus closer to the voltage source. This makes it possible to minimize the lengths of tracks, and thus to reduce the inductive effects. This also makes it possible to place the RC filter as close as possible to the voltage source.
• the voltage source is likely to generate bounces of electrical signals that the RC filter can cut.
• the connector is slightly recessed to allow the RC filter components, soldered on the printed circuit, to have sufficient space.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Filters And Equalizers (AREA)

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• 2016
  • 2016-01-26 FR FR1650590A patent/FR3047130B1/fr not_active Expired - Fee Related
• 2017
  • 2017-01-25 WO PCT/FR2017/050166 patent/WO2017129903A1/fr active Application Filing
  • 2017-01-25 EP EP17707600.7A patent/EP3408930A1/de not_active Withdrawn

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