DE102022124564A1 - Determining filter parameters of a bandpass frequency filter in a vehicle power system - Google Patents

Abstract

The invention relates to a method for determining filter parameters of a passive bandpass frequency filter to be installed in an on-board energy network of a vehicle, in which a model of the on-board energy network is set up with interference sources and interference sinks, an access point of the bandpass frequency filter is determined in the model of the on-board energy network and following starting with k = 1 (a) a kth bandpass filter stage is added to the bandpass frequency filter by (i) specifying a filter stage frequency, then (ii) specifying a filter stage resistance (Rk), then (iii) a filter stage capacitance is determined and a filter stage inductance is calculated from the filter stage frequency and the filter stage capacitance, and following (b) it is calculated based on the model whether transfer impedances caused by the bandpass frequency filter between the interference sources and the interference sinks exceed a predetermined maximum deviation from associated reference transfer impedances or not , and (c) if the maximum deviation is not exceeded, the design of the bandpass frequency filter is completed, (d) while if the maximum deviation is exceeded, k is incremented and following (e) steps (a) to ( d) are run through again, wherein in step (a) (iii) the filter stage capacity is determined according to whether a stability boundary condition with a maximum filter stage capacity, an equilibrium boundary condition with a minimum filter stage capacity or a loss boundary condition with a target filter stage capacity is selected.

Description

The invention relates to a method for determining filter parameters of a passive bandpass frequency filter to be installed in an on-board energy network of a vehicle, in which a model of the on-board energy network is set up with interference sources and interference sinks, an access point of the bandpass frequency filter is determined in the model of the on-board energy network, and following starting with k = 1 (a) a kth bandpass filter stage is added to the bandpass frequency filter by (i) specifying a filter stage frequency, then (ii) specifying a filter stage resistance, then (iii) specifying a filter stage capacitance and a filter stage inductance is calculated from the filter stage frequency and the filter stage capacitance, and (b) using the model it is calculated whether transfer impedances caused by the bandpass frequency filter exceed a predetermined maximum deviation from associated reference transfer impedances or not, and (c) if the maximum deviation is not exceeded, the design of the bandpass frequency filter is completed, (d) while if the maximum deviation is exceeded, k is incremented and following (e) steps (a) to (d) are repeated. The invention also relates to a vehicle having an on-board power supply system with at least one multi-stage frequency filter, the frequency filter being designed or laid out according to the method. The invention is particularly advantageously applicable to on-board energy systems of fully electrically powered vehicles.

To reduce the effects of highly dynamic power fluctuations, multi-stage bandpass filters can be used. This describes it Martin Baumann, Ali Shoar Abouzari, Christoph Weissinger, Bjørn Gustavsen, Hans-Georg Herzog: “Passive Filter Design Algorithm for Transient Stabilization of Automotive Power Systems”, 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), April 25th - 28th 2021, Helsinki, Finland that the automotive electrical system is increasingly being expanded to include highly dynamic power electronics. These components can potentially cause malfunctions or failures of safety-related low-voltage components. The susceptibility to interference is often reduced by using oversized passive input electronics. This paper presents an alternative means of interference suppression through the introduction of system-integrated adaptive passive filters. A proposed method for investigating the suitability of potential access points within complex networks is presented. An algorithmic method for parameterizing several switchable bandpass filter stages is explained. Measurements in the vehicle show the effectiveness of the dimensioned filter, which can reduce interference at 70 kHz by more than 75%. However, only serial equivalent switching parameters are used for the electrical description of the wiring harness, while no cross-plates are considered. The filter parameterization set up is only suitable for such modeling. This publication is incorporated in its entirety into this disclosure.

It is the object of the present invention to at least overcome the disadvantages of the prior art and in particular to provide an improved possibility of taking into account influences between a, in particular multi-stage, frequency filter installed in an on-board energy network of a vehicle and other components of the on-board energy network.

This task is solved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

1. (a) dem Bandpass-Frequenzfilter eine k-te Bandpass-Filterstufe hinzugefügt wird, indem dafür (i) eine Filterstufenfrequenz festgelegt bzw. berechnet wird, dann (ii) ein Filterstufenwiderstand festgelegt bzw. berechnet wird, dann (iii) eine Filterstufenkapazität festgelegt wird und aus der Filterstufenfrequenz und der Filterstufenkapazität eine Filterstufeninduktivität berechnet wird, und folgend
2. (b) anhand des Modells berechnet wird, ob die durch das Bandpass-Frequenzfilter bewirkten Transferimpedanzen zwischen den Störquellen und den Störsenken eine vorgegebene Maximalabweichung von zugehörigen Referenz-Transferimpedanzen überschreiten oder nicht, und
3. (c) dann, wenn die Maximalabweichung nicht überschritten wird, die Auslegung des Bandpass-Frequenzfilters abgeschlossen wird,
4. (d) während dann, wenn die Maximalabweichung überschritten wird, k inkrementiert wird und folgend
5. (e) die Schritte (a) bis (d) erneut durchlaufen werden,

wobei

• - die Filterstufenkapazität danach festgelegt wird, ob eine Stabilitätsrandbedingung mit einer maximalen Filterstufenkapazität, eine Gleichgewichtsrandbedingung mit einer minimalen Filterstufenkapazität oder eine Verlust-Randbedingung mit einer Ziel-Filterstufenkapazität ausgewählt ist.

The task is solved by a method for determining filter parameters of a passive bandpass frequency filter to be installed in an on-board energy network of a vehicle, in which a model of the on-board energy network is set up with interference sources and interference sinks, and an access point of the bandpass frequency filter is determined in the model of the on-board energy network , and following starting with k = 1

1. (a) a kth bandpass filter stage is added to the bandpass frequency filter by (i) setting or calculating a filter stage frequency, then (ii) setting or calculating a filter stage resistance, then (iii) setting a filter stage capacitance and a filter stage inductance is calculated from the filter stage frequency and the filter stage capacitance, and following
2. (b) the model is used to calculate whether the transfer impedances caused by the bandpass frequency filter between the interference sources and the interference sinks exceed a predetermined maximum deviation from associated reference transfer impedances or not, and
3. (c) if the maximum deviation is not exceeded, the design of the bandpass frequency filter is completed,
4. (d) while if the maximum deviation is exceeded, k is incremented and following
5. (e) steps (a) to (d) are repeated again,

where

• - the filter stage capacity is determined according to whether a stability boundary condition with a maximum filter stage capacity, an equilibrium boundary condition with a minimum filter stage capacity or a loss boundary condition with a target filter stage capacity is selected.

This method has the advantage that not only the voltage stability but also the energy loss of the filter can be selected. Another advantage is that the method is also effective for tightly branched on-board power systems (e.g. with a tree structure, narrow cable bundles with pronounced mutual inductances, etc.).

The process automatically adds and designs a filter stage if the previous number of filter stages could not achieve a sufficiently good filter result. In the simplest case, if the first filter stage already produces a sufficiently good filter result, the frequency filter can also be a single-stage filter.

In a further development, the frequency filter is a multi-stage frequency filter, with each of the individual filter stages being designed as a bandpass.

The fact that the frequency filter is a passive filter means in particular that its filter characteristics can be expressed or can be defined by filter parameters in the form of the filter stage resistance R _k , the filter stage capacitance C _k and the filter stage inductance L _k . The filter stage frequency corresponds in particular to the center frequency of the associated pass band.

It is a further development that the filter stages of the multi-stage frequency filter are permanently switched on. It is a further development that the filter stages of the multi-stage frequency filter can be selectively switched on and off via respective switches, in particular electronic switches, for example as described further below in relation to 2 described.

Setting up a model of an on-board energy network is basically known and can be done, for example, as in the publication by Baumann et al. described.

A source of interference can be, for example, a consumer or an energy source such as a DC-DC converter, a comfort component and/or a highly dynamic safety-relevant (ASIL) component that is capable of causing high dynamic power fluctuations in the on-board energy system. An interference sink can, for example, be a highly vulnerable and/or safety-relevant consumer such as an integrated braking system, an electrically driven power steering, a windshield wiper motor, sensors or computing devices. An interference sink can also be a power supply such as a DC-DC converter. A component can be a source of interference and a sink of interference at the same time. Interference sources, interference sinks and bandpass frequency filters are connected to various access points in the on-board electrical system. The bandpass frequency filter is connected to the electrical path in order to reduce interference, in particular interference caused by the interference sources at the interference sinks, for example at connection terminals thereof.

The access point of the bandpass frequency filter in the on-board energy network or in the model of the on-board energy network can, for example, as in the publication by Baumann et al. described.

Subsequently, the frequency filter can be set up by first adding a first filter stage (ie, k = 1) to the frequency filter and determining the corresponding filter stage frequency f _k as well as the filter parameters R _k , C _k , L _k according to steps (a) to (d).

Step (b) can generally correspond to a check as to whether the transfer impedances resulting from adding a filter stage in a frequency range outside the previously added passbands are worse than before the last filter stage was installed. If this is the case, a new filter stage is added, which is designed for the frequency or frequency range that is worse than before the last filter stage was installed. It is a further development that the filter (stage) frequency of the new filter stage (if necessary) is set so that it corresponds to the frequency at which, when comparing the transfer impedances in step (b), a filter with a number one lower of filter stages resulted in the maximum deviation.

In the following, “current” transfer impedances are understood to mean those transfer impedances that result from the presence of the bandpass frequency filter with the currently assigned or used k. If steps (a) to (c) are carried out for the first time and k = 1, the reference transfer impedances correspond to ideal transfer impedances, ie, transfer impedances that would result if an ideal supercapacitor was used at the access point instead of the first filter stage . When going through step (b) for the first time, i.e. when only the first filter stage has been added (case k = 1), it is checked whether the transfer impedances caused by the single-stage bandpass frequency filter have a predetermined maximum deviation δ _max of may or may not exceed the associated “ideal” reference transfer impedances. The associated ideal transfer impedances between interference sources and interference sinks can, for example, as in the publication by Baumann et al. can be calculated as described.

If a further filter stage has been added (ie that k > 1 is present), when step (b) is repeated, it is checked whether the current transfer impedances caused by the current bandpass frequency filter with the newly added kth filter stage have a predetermined maximum deviation δ _max of “initial” transfer impedances, ie, of transfer impedances that would result for the original on-board electrical system, ie, without the bandpass frequency filter and without supercapacitor. The transfer impedances of a filter with k (k > 1) filter stages are compared with the “initial” transfer impedances of the original on-board electrical system. Reference transfer impedances correspond to ideal transfer impedances for k = 1 and initial transfer impedances for k > 1.

A transfer impedance, which can also be referred to as a “transfer function”, is understood here in particular to be a plot or curve of an impedance or a resistance over a frequency range under consideration. Furthermore, the transfer function contains not only the amplitude but also the phase. The unit of the amplitude can be specified, for example, in ohms. The transfer impedances can be, for example, as in the publication by Baumann et al., 3 be applied as described. In the present case, considering a frequency range between 10 kHz and 150 kHz is particularly advantageous.

The fact that it is checked whether the (current) transfer impedances caused by the bandpass frequency filter exceed a predetermined maximum deviation from the associated reference transfer impedances can, in a further development, include this comparison being carried out for all or only a subset of the individual transfer impedances between a specific pair interference source and interference sink is carried out.

It is a particularly easy to implement further development that in order to check whether the transfer impedances caused by the bandpass frequency filter exceed a predetermined maximum deviation from the associated reference transfer impedances, the sum of all current transfer impedances, which are determined by using a filter with the last added k- th filter stage can be compared with the sum of all reference transfer impedances. This sum corresponds to a superposition of all transfer impedances for a specific k and can also be referred to as a “sum curve”.

It is a further development that checking whether the (current) transfer impedances caused by the bandpass frequency filter exceed a predetermined maximum deviation from the associated reference transfer impedances includes, in particular, checking whether a through for at least one frequency value considered by the transfer impedances The amplitude value of the current transfer impedances caused by the current bandpass frequency filter, in particular a sum thereof, has a negative deviation from the amplitude value of the reference transfer impedances, which is greater in magnitude than the predetermined maximum deviation. This is particularly advantageous for dampening antiresonances.

For the case of the stability boundary condition, a maximum filter stage capacity is specified as the filter stage capacity, for the case of the equilibrium boundary condition a minimum filter stage capacity is selected and for the case of the loss boundary condition a filter stage capacity is selected corresponding to a target filter stage capacity. This choice of stability boundary condition can be selected, for example, based on a specified installation space, a specified target weight or a low price for large quantities. The stability boundary condition causes relatively high losses with particularly stable filtering, the equilibrium boundary condition causes relatively low losses with higher frequency selectivity and the loss boundary condition causes a compromise between these two extremes.

It is an embodiment that, in the event that the stability boundary condition is selected, in step (a)(iii) a value of the filter stage capacitance is equated to an upper limit value C _UB , then it is checked whether the remaining deviation between the current transfer impedances and the associated reference transfer impedances is equal to a predetermined minimum deviation, if this is the case, proceed to step (b), and if this is not the case, the filter stage resistance is readjusted or adjusted. The upper limit value C _UB can result, for example, from the maximum capacity C _max of available capacitance components or capacitors and/or can be limited by a minimum inductance L _min of available induction components or coils that can be fitted or the inductance of the circuit board and by the filter stage frequency f _k . The readjustment can, for example, involve an iterative change in the filter stage resistance R _k to find the smallest possible deviation δ _min between the current transfer impedances associated reference transfer impedances.

mit C_max einem maximalen Kapazitätswert verfügbarer Kapazitätsbauteile und L_min einem minimalen Induktivitätswert verfügbarer Induktionsbauteile festgelegt wird.It is an embodiment that the upper limit C _UB according to $${\text{C}}_{\text{UB}}=\text{min}\left\{{\text{C}}_{\text{Max}},\frac{1}{4{\mathrm{\pi }}^2{f}_k{}^2{\text{L}}_{\text{min}}}\right\}$$

with C _max a maximum capacity value of available capacitance components and L _min a minimum inductance value of available induction components.

• - einem unteren Grenzwert C_LB gleichgesetzt wird, falls ein Wert der Ziel-Filterstufenkapazität C_tar kleiner oder gleich dem unterem Grenzwert C_LB ist,
• - auf den Wert der Ziel-Filterstufenkapazität C_tar festgelegt wird, falls der Wert der der Ziel-Filterstufenkapazität C_tar größer als der untere Grenzwert C_LB und kleiner als der obere Grenzwert C_UB ist und
• - dem oberen Grenzwert C_UB gleichgesetzt wird, falls der Wert der Ziel-Filterstufenkapazität C_tar größer oder gleich dem oberen Grenzwert C_UB ist.

It is an embodiment that, in the event that the equilibrium boundary condition is selected, a target filter stage capacity C _tar is first equated to a predetermined minimum filter stage capacity C* _min and then the filter stage capacity C _k

• - is equated to a lower limit value C _LB if a value of the target filter stage capacity C _tar is less than or equal to the lower limit value C _LB ,
• - is set to the value of the target filter stage capacity C _tar if the value of the target filter stage capacity C _{tar is} greater than the lower limit C _LB and smaller than the upper limit C _UB and
• - the upper limit value C _UB is equated if the value of the target filter stage capacity C _tar is greater than or equal to the upper limit value C _UB .

mit C_min einem minimalen Kapazitätswert verfügbarer Kapazitätsbauteile und L_max einem maximalen Induktivitätswert verfügbarer Induktivitätsbauteile festgelegt wird.It is an embodiment that the lower limit C _LB according to $${\text{C}}_{\text{L.B}}=\text{Max}\left\{{\text{C}}_{\text{min}},\frac{1}{4{\mathrm{\pi }}^2{\text{f}}_{\text{k}}{}^2{\text{L}}_{\text{Max}}}\right\}$$

with C _min a minimum capacitance value of available capacitance components and L _max a maximum inductance value of available inductance components.

The minimum filter stage capacity C* _min is set in particular to C min the first time the above method is run through, when the number k of filter stages has not yet reached the permissible maximum number k _max , i.e. to C* _min = C _{min .} C* _min can be increased by a certain level by running through the above process again, starting at k = 1, after the number k of filter stages has previously reached the maximum number k _max . This is explained in more detail below.

It is an embodiment that, in the event that the loss boundary condition is selected, a target filter stage capacity C _tar is set equal to the filter stage capacity C _k and the filter stage capacity C _k is set equal to a lower limit value C _LB if the value of the target filter stage capacity C _tar is less than or equal to the lower limit C _LB , is set to the value of the target filter stage capacity C _tar if the value of the target filter stage capacity is greater than the lower limit and less than an upper limit and an upper limit C _UB is equated if the value of the target filter stage capacity C _tar is greater than or equal to the upper limit C _UB . Here, the target filter stage capacity C _tar is used as the filter stage capacity C _k if the target filter stage capacity C _tar is within the limit values C _LB and C _UB , otherwise forced to the next limit value C _LB and C _UB

berechnet wird.It is an embodiment that the filter stage inductance according to $${\text{L}}_{\text{k}}=\frac{1}{4{\mathrm{\pi }}^2{\text{f}}_{\text{k}}{}^2{\text{C}}_{\text{k}}}$$

is calculated.

• - ein Absolutwert der idealen Transferimpedanz als anfänglicher Filterstufenwiderstand R₁ bei der identifizierten Filterstufenfrequenz f₁ verwendet wird und
• - dann, wenn eine anfängliche Abweichung δ* zwischen u_gefiltert und u_ideal größer als eine maximal zulässige Abweichung δ*_max ist, der Filterstufenwiderstand R₁ sukzessive verringert wird, bis die Abweichung δ* die maximal zulässige Abweichung δ*_max erreicht, und
• - dann, wenn die anfängliche Abweichung δ* zwischen u_gefiltert und u_ideal kleiner als die maximal zulässige Abweichung δ*_max ist, der Filterstufenwiderstand R₁ sukzessive erhöht wird, bis die Abweichung δ* die maximal zulässige Abweichung δ*_max erreicht,

und für folgende Filterstufen (d.h., für k > 1) jeweils eine polynominale Näherungsfunktion der Ordnung n, welche mehrere iterativ gerechnete Testpaare (R_k,i, δ_k,i) annähert, bestimmt wird und als der Filterstufenwiderstand R_k ein Wert der Näherungsfunktion festgelegt wird, der innerhalb einer vorgegebenen Abweichung zum Funktionswert null liegt. Die Größe u_gefiltert entspricht dabei der Amplitude der Transferimpedanz mit Filter an einer bestimmten Frequenz und u_ideal der Amplitude der Transferimpedanz an dieser Frequenz mit idealer Stabilisierung. Dass der Filterstufenwiderstand R₁ sukzessive verringert wird, kann insbesondere umfassen, dass er in Schritten mit insbesondere gleicher Schrittweite verringert wird, z.B. in Schritten von 1 mΩ.It is an embodiment that in step (a)(ii) the filter stage resistance is determined by for the first filter stage, ie, for k = 1,

• - an absolute value of the ideal transfer impedance is used as the initial filter stage resistance R ₁ at the identified filter stage frequency f ₁ and
• - then, if an initial deviation δ* between u _filtered and u is _ideally greater than a maximum permissible deviation δ* _max , the filter stage resistance R ₁ is successively reduced until the deviation δ* reaches the maximum permissible deviation δ* _max , and
• - then, if the initial deviation δ* between u _filtered and u _ideally is smaller than the maximum permissible deviation δ* _max , the filter stage resistance R ₁ is successively increased until the deviation δ* reaches the maximum permissible deviation δ* _max ,

and for the following filter stages (ie, for k > 1), a polynomial approximation function of order n, which approximates several iteratively calculated test pairs (R _k,i , δ _k,i ), is determined and a value of the approximation function as the filter stage resistance R _k which is within a predetermined deviation from the function value zero. The size u _filtered corresponds to the amplitude of the transfer impedance with filter at a certain frequency and u _{ideally corresponds} to the amplitude of the transfer impedance dance at this frequency with ideal stabilization. The fact that the filter stage resistance R ₁ is successively reduced can in particular include that it is reduced in steps with, in particular, the same step size, for example in steps of 1 mΩ.

The test pairs (R _k,i , δ _k,i ) form in particular the support points for the approximation function. In the case of three test pairs (R _k,i , δ _k,i ) with j = 1, 2, 3, these can be determined, for example, such that for j = 1 the absolute value of the ideal transfer impedance is assumed, for j = 2 a double value of the resistance is assumed and for j = 3 a half value of the resistance is assumed.

It is a further development that a value is set as the filter stage resistance R _k , which results in the smallest deviation from the functional value zero from a set of actually available resistance components.

lautet. Dies umfasst insbesondere, dass es für jede Filterstufe und damit Filterstufenfrequenz f_k eine solche polynomiale Näherungsfunktion gibt.It is an embodiment that the polynomial approximation function $${\mathrm{\delta }}_{\text{k}}\left({\text{f}}_{\text{k}}\right)={\text{a R}}_{\text{k}}{\left({\text{f}}_{\text{k}}\right)}^2+{\text{b R}}_{\text{k}}\left({\text{f}}_{\text{k}}\right)+\text{c}$$

is. This includes in particular that there is such a polynomial approximation function for each filter stage and thus filter stage frequency f _k .

$$b=\frac{\left({\delta }_1-{\delta }_3\right)-a\left(R_1{}^2-R_3{}^2\right)}{\left(R_1-R_3\right)}$$

$$c={\delta }_1-a{R}_1{}^2-b{R}_1$$

$$d=\frac{R_1-R_2}{R_1-R_3}$$

berechnet werden.It is an embodiment that the coefficients a, b, c of the polynomial approximation function based on three test pairs (R _k,1; δ _k,1 ) using the equations $$a=\frac{\left({\mathrm{<figure-callout\; id="1"\; label="\delta "\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">\delta </figure-callout>}}_1-{\delta }_2\right)-d\left({\mathrm{<figure-callout\; id="1"\; label="\delta "\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">\delta </figure-callout>}}_1-{\delta }_3\right)}{\left({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1{}^2-{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_2{}^2\right)-d\left({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1{}^2-R_3{}^2\right)}$$

$$b=\frac{\left({\mathrm{<figure-callout\; id="1"\; label="\delta "\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">\delta </figure-callout>}}_1-{\delta }_3\right)-a\left({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1{}^2-R_3{}^2\right)}{\left({\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1-R_3\right)}$$

$$c={\mathrm{<figure-callout\; id="1"\; label="\delta "\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">\delta </figure-callout>}}_1-a{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1{}^2-\mathrm{<figure-callout\; id="1"\; label="b\; R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">b</figure-callout>}{R}_{}{}_1$$

$$d=\frac{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1-R_2}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="DE102022124564A1\_0020.png,DE102022124564A1\_0021.png"\; state="\{\{state\}\}">R</figure-callout>}}_1-R_3}$$

be calculated.

• - wenn dies der Fall ist, k inkrementiert wird,
• - wenn dies nicht mehr der Fall ist, k auf den Wert k = 1 zurückgesetzt wird (also der Frequenzfilter ganz neu aufgebaut wird) und dazu mindestens eine Anfangseinstellung geändert wird, bevor das Verfahren erneut durchlaufen wird. Das Verfahren kann abgebrochen werden, wenn unter keiner der gewählten Anfangseinstellungen die Abweichung δ geringer ist als die Maximalabweichung δ_max. Alternativ zum Abbruch des Verfahrens kann ein anderer Zugangspunkt gewählt werden.

It is an embodiment that, if the maximum deviation is exceeded in step (d), it is first checked whether k is still below a maximum value k _max , and

• - if this is the case, k is incremented,
• - if this is no longer the case, k is reset to the value k = 1 (i.e. the frequency filter is completely rebuilt) and at least one initial setting is changed before the process is repeated. The procedure can be aborted if the deviation δ is less than the maximum deviation δ _max under any of the selected initial settings. As an alternative to aborting the procedure, another access point can be selected.

• - Änderung der Randbedingung (Wechsel zwischen Stabilitätsrandbedingung, Gleichgewichtsrandbedingung und Verlust-Randbedingung),
• - Nutzung eines anderen, insbesondere größeren, Filterstufenwiderstands R_k=1,
• - bei Verwendung der Gleichgewichtsrandbedingung: Erhöhen des Werts der Filterstufenkapazität C_k um eine Stufe.

Possible changes to the initial setting may include, for example:

• - Change of the boundary condition (change between stability boundary condition, equilibrium boundary condition and loss boundary condition),
• - Use of a different, in particular larger, filter stage resistance R _{k = 1} ,
• - when using the equilibrium boundary condition: increasing the value of the filter stage capacity C _k by one stage.

The object is also achieved by a vehicle having an on-board power supply system with at least one multi-stage frequency filter, wherein the frequency filter has been designed according to a method as described above. The vehicle, in particular its on-board power supply system, can be designed analogously to the method and has the same advantages.

It is an embodiment that the multi-stage frequency filter is integrated into a power distributor of the on-board power system. The power distributor is used to connect several electrical components (loads, consumers, etc.) to the on-board power system and, for this purpose, in particular has respective (individual) power branches with corresponding connections or connection terminals. The components that can be connected are basically any and can include safety-relevant (ASIL) and/or non-safety-relevant comfort (QM) components. In particular, the individual current branches can each be protected with a fuse (E-fuse or fuse) in order to be able to quickly and selectively isolate errors in highly available on-board energy systems.

It is an embodiment that the on-board energy network is a low-voltage on-board energy network, in particular a low-voltage on-board energy network. The low-voltage on-board power supply system can, for example, have a nominal voltage between 12 V and 60 V. If the on-board energy network is a low-voltage on-board energy sub-network, it can be part of an overall on-board energy network, which also has a high-voltage on-board energy sub-network, for example with a nominal voltage that is higher than the nominal voltage of the low-voltage on-board energy sub-network, for example between 48 V and 800 V or even higher.

The vehicle can be, for example, a vehicle with a combustion engine, a hybrid vehicle or a fully electric vehicle. The vehicle may be, for example, a land vehicle such as a passenger car, a motorcycle, a bus, a truck, etc., an aircraft such as an airplane, a helicopter, etc., or a watercraft such as a ship, etc.

• 1 zeigt einen Ausschnitt aus einem Ersatzschaltbild eines möglichen Energiebordnetzes eines Fahrzeugs mit mehreren Stromverteilern;
• 2 zeigt ein abstrahiertes Ersatzschaltbild eines mehrstufigen Filters eines Stromverteilers des Energiebordnetzes aus 1;
• 3 zeigt einen möglichen Ablauf eines Verfahrens zum Bestimmen von Filterparametern eines in dem Energiebordnetz des Fahrzeugs aus 1 zu verbauenden Frequenzfilters; und
• 4 zeigt einen der Schritte aus 3 in höherer Detaillierung.

The characteristics, features and advantages of this invention described above and the manner in which they are achieved will be more clearly and clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a section of an equivalent circuit diagram of a possible on-board power system of a vehicle with several power distributors;
• 2 shows an abstracted equivalent circuit diagram of a multi-stage filter of a power distributor in the on-board power system 1 ;
• 3 shows a possible sequence of a method for determining filter parameters in the vehicle's on-board energy system 1 frequency filter to be installed; and
• 4 shows one of the steps 3 in higher detail.

1 shows based on its partial images 1(A) and 1(B) a section of an equivalent circuit diagram of an on-board energy network EBN of a vehicle F. The on-board energy network EBN has a low-voltage (LV) sub-board network, which consists of a high-voltage (HV) sub-board network with an HV network voltage VHV via several galvanically isolated DC-DC converters GSW1, GSW2, GSW3 is supplyable. The DC-DC converters GSW1, GSW2, GSW3 convert the higher HV mains voltage VHV of the HV sub-board network into a respective lower LV voltage V_CM, V_CS1 or V_CS2. The DC-DC converters GSW1, GSW2, GSW3 are connected to a communication channel of the vehicle F, here for example a CAN bus CAN, and can communicate with one another via this. In particular, the DC-DC converters GSW1, GSW2, GSW3 can be present in a master-slave arrangement, with, for example, the DC-DC converter GSW1 being used as a master and the DC-DC converters GSW2, GSW3 being used as slaves.

The LV voltages V_CM, V_CS1 and V_CS2 are applied here via a respective node A, B and C to a locally extended wiring harness KB of the LV sub-board network, namely via lines with respective line impedances Z_L, CM, Z_L, CS1 and Z_L ,CS2. Adjacent nodes, A and B, B and C, etc. of the extended wire harness KB are typically separated from one another by line sections with line impedances Z_L,AB, Z_L,BC, etc.

A battery BAT is also connected to the cable harness KB, here for example at node A via a line with line impedance Z_L, BAT.

Several electrical components are also connected to the wiring harness KB of the NV sub-board network, via at least one (here: two) power distributors PD1, PD2. In the present case, the power distributors PD1 and PD2 are connected to nodes B and C via line impedances Z_L,PD1 and Z_L,PD2, respectively. Both safety-relevant (ASIL) components such as an integrated brake system, IB, an electrically driven power steering, EPB, windshield wiper motor, WIP, etc. as well as comfort (QM) components such as an electric fan, ELF and rear axle steering, RAS, must be connected. The impedances present in the individual current branches are here as the line impedances Z_MNH,P and as impedances Z_MN,P of the connected components with "M" the number of the power distributor PD1, PD2, "N" the designation for a current branch with "A" for one ASIL component and “Q” for a comfort component as well as “P” the number of the ASIL or comfort component in a respective power distributor PD1, PD2.

In order to avoid interference, particularly in safety-relevant components IB, EPB, WIP, a multi-stage bandpass filter BP1 or BP2 (with respective impedances Zf, PD1 or Zf, PD2) each with several stages FS _j that can be selectively switched on and off. The filters BP1 and BP2 can be designed to be identical or different - for example with regard to the number and/or filter properties of the filter stages FS _j .

The multi-stage bandpass filter BP1, BP2 as well as the electrical components IB, EPB, WIP, ELF, RAS connected to the power distributors PD1, PD2 are protected by respective electronic fuses or “E-Fuses” EFi (see 2 ) secured.

In principle, one or more power distributors PDi with i ≥ 1 can be present in the LV sub-board network, i.e. more than two power distributors PD1, PD2. In particular, at least one safety-relevant component IB, EPB, WIP and/or at least one can be connected to each of the power distributors PDi At least one comfort component ELF, RAS must be connected.

In order to further reduce interference, especially from components IB, EPB, WIP, ELF, RAS, etc. - especially safety-relevant ones - additional frequency filters and/or electronic fuses (not shown) can be present in the associated individual current branch are intended to specifically secure the respective components IB, EPB, WIP, ELF, RAS, etc. These additional frequency filters can advantageously be smaller when the filters BP1 and BP2 are present than without filters BP1 and BP2.

2 shows an abstracted equivalent circuit diagram of a multi-stage passive bandpass filter BPi integrated in one of the PDi power distributors with the EBN on-board power system. The BPi filter is optionally protected by a low-impedance electronic fuse EFi, which can be switched to conductive or blocking using the Q _fuse switch. The electronic fuse EFi is located in the same individual current branch as the bandpass filter BPi and is advantageously connected upstream of it, possibly installed in a common module with the bandpass filter BPi.

The multi-stage filter BPi comprises k = 1, ..., k _max (here: k _max > 2) parallel-connected bandpass filter stages FS _n with a respective fixed parameterized combination of ohmic resistance R _n , electrical inductance L _k and electrical capacitance C _k , whose values can be viewed as filter parameters. The bandpass filter stages FS _k can optionally be switched on or off from the power supply via respective electronic switches Q _k . The electronic switches Q _k are designed here as low-impedance MOSFETs.

The filter stages FS _n are protected from short-term voltage pulses by a bidirectional suppressor diode D ₁ internal to the multi-stage filter BPi.

The electronic switches Q _k are controlled by means of a gate driver GT of the power distributor PDi, which in turn is adjusted by means of a control device ECU of the power distributor PDi, for example in the form of a microcontroller. The ECU control device receives changes via the CAN bus CAN via a switching state of the NV sub-board network. The control device ECU compares a change in the switching state or the then current switching state of the NV sub-board network with a database, in particular a lookup table stored therein, in which each possible switching state of the LV sub-board network is assigned a corresponding discrete (switching) configuration of the filter BPi assigned. A discrete configuration of the filter BPi is understood to mean, in particular, a specific combination of conductive/blocking circuits of the electronic switches Q _j . For this purpose, the configuration of the filter BPi stored for a specific switching state of the LV sub-board network is the discrete configuration of the filter BPi that is most suitable for suppressing resonances in the LV sub-board network under this switching state of the LV sub-board network. For each switching state of the LV sub-board network, there is in particular exactly one filter parameterization of the filter BPi, which is determined by the associated switching on and off of the stages FS _k . In yet other words, the control device ECU interprets or determines the associated configuration of the electronic switches Q _k of the filter BPi based on the information about the switching state of the LV sub-board network communicated via the CAN bus CAN.

The discrete switching state of the filter BPi looked up by the control device ECU is passed on to the gate driver GT, which switches the electronic switches Q _k accordingly.

A system voltage V _s corresponds to the voltage detected at the power distributor PDi between its node B, C or similar and the local reference potential (ground).

3 shows a possible sequence of a method for determining filter parameters R _k , C _k , L _k of an EBN in the on-board energy network of the vehicle 1 1 BPi passive bandpass frequency filter to be installed with potentially several (k ≥ 2) filter stages.

In a step S0, in a sub-step S0-1, a model of the on-board energy network EBN with interference sources and interference sinks is set up, then a list of i = 1, ..., N access points AP _i is generated and also interference sources and interference sinks in the on-board energy network EBN are defined.

In a sub-step S0-2, one of the access points AP _i is then selected and in a sub-step S0-3, ideal transfer impedances are calculated for it, for example as described in the publication by Baumann et al., Chapter IV.A.

In a sub-step S0-4, it is checked whether the selected access point AP _i is suitable, and if not (“N”), a new access point AP _j is selected in sub-step S0-2. However, if the selected access point AP _i is suitable (“J”), a transition is made to a process block _ABL , in which the filter parameters R _k , C _k , L _k of a passive k-stage bandpass frequency filter BPi located there are determined for the access point AP i become. An access point is particularly suitable if using a The ideal transfer impedance of an ideal filter for this point or location can be determined so that there is an improvement compared to an original state without a filter. Due to the inductive coupling, not every location in the on-board power system is suitable for a filter: it is possible that only negative deviations or anti-resonances occur at an unsuitable access point or location.

However, step S0 can also be performed analogously to the one in the publication by Baumann et al., 5 above the drain block shown there in dashed lines.

Following step S0, in a step S1, starting with k = 1, a kth bandpass filter stage FS _k is added to the bandpass frequency filter BPi, the filter stage frequency f _k of which is fixed, for example as in the publication by Baumann et al, chap . IV described. The filter stage frequency f _k is determined so that antiresonances are attenuated, in particular in a frequency range between 10 kHz and 150 kHz.

In a step S2, a filter stage resistance R _k is then determined for the filter stage FS _k , for example as in the publication by Baumann et al, chap. IV.A described or, advantageously, using the polynomial approximation function described above.

In a step S3, a filter stage capacitance C _k is determined and a filter stage inductance L _k = f (f _k , C _k ) is calculated from the filter stage frequency f _k and the filter stage capacitance C _k . The filter stage capacity C _k is determined according to which of the following boundary conditions: "Stability boundary condition" RB-S with a maximum filter stage capacity, "Equilibrium boundary condition" RB-G with the lowest possible filter stage capacity or "Loss boundary condition" RB-V with a target filter stage capacity is selected is. Step S3 will be in 4 detailed.

Subsequently, in a step S4, it is calculated using the model for filter parameters R _k , C _k , L _k whether the transfer impedances caused by the bandpass frequency filter BPi for all frequency values under consideration are no more than the predetermined maximum deviation δ _max below the reference transfer impedances the same frequency values or not, that is, whether a downward deviation δ of the currently calculated transfer impedances from the reference transfer impedances is less than a predetermined maximum deviation δ _max . This can be implemented in particular in such a way that all current transfer impedances for the current k are superimposed to form a “current sum curve” and all reference transfer impedances are superimposed to form a “reference sum curve” and it is then checked whether for all frequencies considered in the transfer impedances the value of the amplitude of the current cumulative curve is less than the maximum deviation δ _max less than the frequency-corresponding value of the amplitude of the reference cumulative curve.

If this is the case (“Y”), the design for the bandpass frequency filter is completed in step S5 or the filter design for the access point AP _i is ended.

However, if the downward deviation δ reaches the maximum deviation δ _max for at least one frequency or is even greater in magnitude (“N”), it is checked in step S6 whether k is still below a predetermined maximum number k _max for this bandpass frequency filter BP _i permitted filter levels. k _max can, for example, be specified by an available installation space.

If this is the case (“Y”), k is incremented by one (which can also be written as k := k+1 or k++) and branched to step S1. This causes a new filter stage FS _k+1 to be set up. The filter stage frequency f _k+1 of the new filter stage FS _k+1 is determined in particular so that it corresponds to the frequency at which the maximum deviation resulted when comparing the transfer impedances in step S4. When branching to step S1, k > 1 is present, which means that in step S4 the transfer impedances for the then current bandpass frequency filter BPi with k filter stages are compared with the transfer impedances of the previous bandpass frequency filter BPi with (k-1) filter stages , while at k = 1 no “previous” bandpass frequency filter exists and is therefore compared with the ideal transfer impedances.

However, if this is not the case (“N”) and the number of filter stages FS _i has reached the maximum number k _max , k is reset to the value k = 1 in step S7 (i.e. the frequency filter is rebuilt) and at least an initial setting is changed before the process is repeated. The procedure can be aborted if the deviation δ is less than the maximum deviation δ _max under any of the selected initial settings. As an alternative to aborting the procedure, another access point can be selected.

• - Änderung der Randbedingung (Wechsel zwischen Stabilitätsrandbedingung RB-S, Gleichgewichtsrandbedingung RB-G und Verlust-Randbedingung RB-V),
• - Nutzung eines anderen, insbesondere größeren, Filterstufenwiderstands R_k für die Filterstufe FS_k in Schritt S2,
• - bei Verwendung der Gleichgewichtsrandbedingung RB-G: Erhöhen des Werts der Filterstufenkapazität C*min (siehe unten) um eine Stufe.

Possible changes to the initial setting may include, for example:

• - Change of the boundary condition (change between stability boundary condition RB-S, equilibrium boundary condition RB-G and loss boundary condition RB-V),
• - Use of a different, in particular larger, filter stage resistance R _k for the filter stage FS _k in step S2,
• - when using the equilibrium boundary condition RB-G: increase the value of the filter stage capacity C*min (see below) by one stage.

4 shows step S3 in greater detail. In a first sub-step S3-1, the boundary condition RG-S, RB-G or RG-V is set, for example according to a setting made automatically or by the user with or before the start of the method or according to a change in the initial setting from step S7.

In substep S3-2 it is checked whether the boundary condition set in substep S3-1 corresponds to the stability boundary condition RB-S. If this is the case (“Y”), the process goes to sub-step S3-3.

festgelegt werden kann.In substep S3-3, the filter stage capacity C _k is set to a predetermined upper limit value C _UB . The upper limit value C _UB can result, for example, from the maximum capacity of available capacitors and/or can be limited by a minimum inductance L _min and the filter stage frequency f _k , so that the filter stage capacity C _k , for example, according to $${\text{C}}_k={\text{C}}_{\text{UB}}=\text{min}\left\{{\text{C}}_{\text{Max}},\frac{1}{4{\mathrm{\pi }}^2{f}_k{}^2{\text{L}}_{\text{min}}}\right\}$$

can be determined.

berechnet.In step S3-4, the filter stage inductance L _k is now determined according to $${\text{L}}_{\text{k}}=\frac{1}{4{\mathrm{\pi }}^2{f}_k{}^2{\text{C}}_{\text{k}}}$$

calculated.

In substep S3-5 it is checked whether a remaining deviation δ of the current transfer impedances from the reference transfer impedances is equal to a minimum deviation δ _min in the entire frequency range under consideration, for example between 10 kHz and 150 kHz. If the remaining deviation δ does not correspond to the minimum deviation δ _min , R _k is approximately recalculated for the filter stage k in substep S3-6. In contrast, in step S4 it is checked whether the remaining deviation δ is too large somewhere in the frequency range under consideration, that is, is greater than δ _max . δ _max can also be smaller than a feasible δ _min from step S3-5.

If this is the case (“Y”), the process goes to step S4.

However, if this is not the case (“N”), in a substep S3-6 the resistance R _k is recalculated based on the previous integration of C _k and L _k , in particular approximated as part of an iterative process. While R _k is calculated in step S2 based on the deviation δ of a frequency f _k , R _k is readjusted in step S3-6 so that the deviation δ is minimal for all frequencies f. The following returns to sub-step S3-5. The readjustment of R _k is carried out in particular because the largest usable capacity C _UB is fixed for the stability boundary condition RB-S and, apart from the resistance R _k, no further degree of freedom is available for reducing the influence of the filter on the transfer impedances.

For the case k=1, the iteration can be implemented in such a way that the deviation δ between the current transfer impedances with bandpass frequency filter and the ideal transfer impedances with ideal stabilization is considered, i.e. that is attempted approximately through sub-steps S3-5 and S3-6 will achieve the ideal stabilization. For further filter stages k > 1, the deviation δ between the transfer impedances with bandpass frequency filter and initial transfer impedance without filter is considered, i.e. the partial steps S3-5 and S3-6 of all further filter stages k > 1 attempt to approximate to compensate for the poor deviation from the initial state achieved by the first stage.

If it has been recognized in sub-step S3-2 that the boundary condition set in sub-step S3-1 does not correspond to the stability boundary condition RB-S (“N”), the process goes to sub-step S3-7, in which it is checked whether the boundary condition set in sub-step S3- 1 set boundary condition corresponds to the equilibrium boundary condition RB-G. If this is the case (“Y”), the process goes to sub-step S3-8.

In substep S3-8, a value C* _min is set as a target value C _tar of the filter stage capacity C _k , for example as explained above.

Subsequently, in substep S3-9, it is checked whether the target value C _tar corresponds to one of three conditions and then the value of the filter stage capacity C _k is set according to the applicable condition.

festgelegt werden kann. Hingegen wird C_k = C_tar gesetzt, wenn C_LB ≤ C_tar ≤ C_UB gilt. Wenn C_tar ≥ C_UB gilt, wird C_k = C_UB gesetzt.Specifically, C _k = C _LB with C _LB a lower limit is set if C _tar ≤ C _LB. The lower limit C _LB can, for example, result from the minimum capacitance of available capacitors and/or can be limited by a maximum inductance L _max and the filter stage frequency f _k , where the filter stage capacitance C _k is, for example, determined according to $${\text{C}}_k={\text{C}}_{\text{LB}}=\text{Max}\left\{{\text{C}}_{\text{min}},\frac{1}{4{\mathrm{\pi }}^2{\text{e}}_{\text{k}}{}^2{\text{L}}_{\text{Max}}}\right\}$$

can be specified. On the other hand, C _k = C _tar is set if C _LB ≤ C _tar ≤ C _UB . If C _tar ≥ C _UB , C _k = C _UB is set.

Subsequently, in step S3-10, the filter stage inductance L _k is calculated analogously to step S3-4 and then proceeded to step S4.

If it has been recognized in sub-step S3-7 that the boundary condition set in sub-step S3-1 does not correspond to the equilibrium boundary condition RB-G (“N”), the process goes to sub-step S3-11, in which it is checked whether the boundary condition set in sub-step S3-1 1 set boundary condition corresponds to the loss boundary condition RB-V. If this is the case (“Y”), the process goes to sub-step S3-9. Alternatively, if it has been recognized in sub-step S3-7 that the boundary condition set in sub-step S3-1 does not correspond to the equilibrium boundary condition RB-G (“N”), you can proceed directly to sub-step S3-9.

Of course, the present invention is not limited to the exemplary embodiment shown.

In general, at least one component IB, EPB, WIP, ELF, RAS connected to a PDi power distributor can also be equipped with its own, permanently parameterized, multi-stage bandpass filter. Furthermore, at least one component IB, EPB, WIP, ELF, RAS connected to a power distributor PDi can be additionally protected by its own fuse, in particular an electronic fuse.

In general, “a”, “an”, etc. can be understood to mean a singular or a plural, in particular in the sense of “at least one” or “one or more”, etc., unless this is explicitly excluded, e.g. by the expression “exactly one”, etc.

A numerical statement can also include exactly the number specified as well as a usual tolerance range, as long as this is not explicitly excluded.

List of reference symbols

A

node

ASIL

Safety-relevant component

b

node

BPi

i-th multi-stage bandpass filter

C

node

Ck

Electrical capacity of the kth filter stage

D1

suppressor diode

EBN

Energy on-board network

ECU

Control device

EFi

Electronic fuse of the i-th power distributor

ELEVEN

Electric fan

EPB

Electrically driven power steering

F

vehicle

FSk

kth filter stage

GSWi

i-th DC-DC converter

GT

Gate driver

IB

Integrated braking system

kmmax

Maximum filter level

Lk

Inductance of the kth filter stage

PDi

i-th power distributor

QM

Comfort component

Qfuse

Electronic fuse switch

Qk

Switch of the k-th filter stage

Rk

Resistance of the kth filter stage

RAS

Rear axle steering

VHV

HV mains voltage

WIP

Windshield wiper motor

Z

impedance

Zl

Line impedance

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Non-patent literature cited

• Martin Baumann, Ali Shoar Abouzari, Christoph Weissinger, Bjørn Gustavsen, Hans-Georg Herzog: “Passive Filter Design Algorithm for Transient Stabilization of Automotive Power Systems”, 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring), April 25th - 28th 2021, Helsinki, Finland [0002]

Claims (14)

Method (S0, S0-1 - S0-4, S2, S3, S3-1 - S3-11, S4 - S7) for determining filter parameters (R _k , C _k , L _k ) in an on-board energy network (EBN). Vehicle (F) to be installed passive bandpass frequency filter (BP1, BP2, BPi), in which - a model of the on-board energy network (EBN) with interference sources (GSW1, GSW2, GSW3, ELF) and interference sinks (IB, EPS, WIP) is set up , - an access point of the bandpass frequency filter (BP1, BP2, BPi) is determined in the model of the on-board energy network (EBN) - and following, starting with k = 1 (a) the bandpass frequency filter (BP1, BP2, BPi) a k- th bandpass filter stage (FS _k ) is added by (i) specifying a filter stage frequency (f _k ), then (ii) specifying a filter stage resistance (R _k ), then (iii) specifying a filter stage capacitance (C _k ). and a filter stage inductance (L _k ) is calculated from the filter stage frequency (f _k ) and the filter stage capacitance (C _k ), and following (b) the model is used to calculate whether transfer impedances caused by the bandpass frequency filter (BP1, BP2, BPi). between the interference sources (GSW1, GSW2, GSW3, ELF) and the interference sinks (IB, EPS, WIP) a predetermined maximum deviation (δ _max ) from associated reference transfer impedances may or may not be exceeded, and (c) if the maximum deviation (δ _max ) is not exceeded, the design of the bandpass frequency filter (BP1, BP2, BPi) is completed, (d) while if the maximum deviation (δ _max ) is exceeded, k is incremented and following (e) steps (a) to (d) are run through again, whereby in step (a)(iii) the filter stage capacity (C _k ) is determined according to whether - a stability boundary condition (RB-S) with a maximum filter stage capacity (C _UB ), - an equilibrium boundary condition (RB -G) with a minimum filter stage capacity (C _LB ) or - a loss boundary condition (RB-V) with a target filter stage capacity (C _tar ) is selected. Procedure (S0, S0-1 - S0-4, S2, S3, S3-1 - S3-11, S4 - S7). Claim 1 , in which, in the event that the stability boundary condition (RB-S) is selected, - in step (a)(iii) a value of the filter stage capacity (C _k ) is equated to an upper limit value (C _UB ), - then checked, whether a remaining deviation (δ) is equal to a minimum deviation (δ _min ), - if this is the case, proceed to step (b), and - if this is not the case, the filter stage resistance (R _k ) is readjusted. Procedure (S0, S0-1 - S0-4, S2, S3, S3-1 - S3-11, S4 - S7) according to Claim 2 , at which the upper limit value (C _UB ) according to $${\text{C}}_{\text{UB}}=\text{min}\left\{{\text{C}}_{\text{Max'}}\frac{1}{4{\mathrm{\pi }}^2{ƒ}_k^2{\text{L}}_{\text{min}}}\right\}$$

with C _max a maximum capacitance value of available capacitance components and L _min a minimum inductance value of available inductance components. Method (S0, S0-1 - S0-4, S2, S3, S3-1 - S3-11, S4 - S7) according to one of the preceding claims, in which the equilibrium boundary condition (RB-G) is selected , a target filter stage capacity is first equated to a predetermined minimum filter stage capacity and then the filter stage capacity - is equated to a lower limit if a value of a target filter stage capacity is less than or equal to the lower limit, - is set to the value of the target filter stage capacity if the value of the target filter stage capacity is greater than the lower limit and smaller than an upper limit and - is equated to an upper limit if the value of the target filter stage capacity is greater than or equal to the upper limit. Procedure according to Claim 4 , at which the lower limit according to $${\text{C}}_{\text{L.B}}=\text{Max}\left\{{\text{C}}_{\text{min'}}\frac{1}{4{\mathrm{\pi }}^2{\text{f}}_{\text{k}}{}^2{\text{L}}_{\text{Max}}}\right\}$$

with C _min a minimum capacitance value of available capacitance components and L _max a maximum inductance value of available induction components. Method according to one of the preceding claims, in which, in the event that the loss boundary condition (RB-V) is selected, the filter stage capacity - is equated to a lower limit if a value of a target filter stage capacity is less than or equal to the lower limit, - is set to the value of the target filter stage capacity if the value of the target filter stage capacity is greater than the lower limit and smaller than an upper limit and - is equated to an upper limit if the value of the target filter stage capacity is greater than or equal to the upper limit. Method according to one of the preceding claims, in which the filter stage inductance according to $${\text{L}}_{\text{k}}=\frac{1}{4{\mathrm{\pi }}^2{\text{f}}_{\text{k}}{}^2{\text{C}}_{\text{k}}}$$

is calculated. Method according to one of the preceding claims, in which in step (a)(ii) the filter stage resistance is determined by using for the first filter stage - the absolute value of the ideal transfer impedance as the initial filter stage resistance R1 at the identified filter stage frequency f1 and - when a initial deviation δ* between an amplitude, u _flitert , the transfer impedance with filter at a certain frequency and an amplitude, u _ideal , the transfer impedance at this frequency with ideal stabilization is greater than a maximum permissible deviation δ _max , the filter stage resistance is successively reduced, until the deviation δ* reaches the maximum permissible deviation δ _max , and - then, when the initial deviation δ* between u _filtered and u is _ideally smaller than the maximum permissible deviation δ _max , the filter stage resistance (R _k ) is successively increased until the deviation δ* reaches the maximum permissible deviation δ _max , and for each of the following filter stages - a polynomial approximation function of order n, which approximates several iteratively calculated test pairs (R _k,i , δ _k,i ), is determined and - as the filter stage resistance a value of the approximation function is determined which lies within a predetermined deviation from the function value zero. Procedure according to Claim 8 , where the polynomial approximation function $${\delta }_k\left({ƒ}_k\right)=a{R}_k{\left({ƒ}_k\right)}^2+b{R}_k\left({ƒ}_k\right)+c$$

is. Procedure according to Claim 9 , in which the coefficients a, b, c of the polynomial approximation function based on three test pairs (R _k,1; δ _k,1 ) using the equations $$a=\frac{\left({\delta }_1-{\delta }_2\right)-d\left({\delta }_1-{\delta }_3\right)}{\left(R_1{}^2-R_2{}^2\right)-d\left(R_1{}^2-R_3{}^2\right)}$$

$$b=\frac{\left({\delta }_1-{\delta }_3\right)-a\left(R_1{}^2-R_3{}^2\right)}{\left(R_1-R_3\right)}$$

$$c={\delta }_1-a{R}_1{}^2-b{R}_1$$

$$d=\frac{R_1-R_2}{R_1-R_3}$$

be calculated. Method according to one of the preceding claims, in which, if the maximum deviation is exceeded in step (d), it is first checked whether k is still below a maximum value k _max and - if this is the case, k is incremented - if this is no longer the case, k is reset to the value k = 1 and at least one initial setting is changed. Procedure according to Claim 11 , in which the change in the initial setting at least one change from the group: - change in the boundary condition (RB-S, RB-G, RG-V), - use of a different, in particular larger, filter stage resistance (R _k ), - when using the Equilibrium boundary condition (RB-G): Increasing a value of the filter stage capacity (C _k ) by one stage. Vehicle comprising an on-board power system with at least one multi-stage frequency filter, wherein the frequency filter has been designed according to a method according to one of the preceding claims. Vehicle after Claim 13 , whereby the multi-stage frequency filter is integrated into a power distributor of the on-board energy system.

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