ELECTRONIC CIRCUIT ARRANGEMENT AND METHOD

Description

[0001] The invention relates to an electronic circuit arrangement for an electric charging station and a method for designing an electrical frequency filter device of such an electronic circuit arrangement.

[0002] When conductively charging electric vehicles with electrical energy using an electric charging station, where the electric vehicle is physically electrically connected to the charging station during such conductive charging, an electrical communication connection is typically established between the electric vehicle and the charging station. The electric vehicle and the electric charging station communicate via this electrical communication connection using a pulse-width-modeled electrical signal, with a positive amplitude of the signal representing the vehicle's status and the pulse width representing a predetermined electrical charging current provided by the charging station.

[0003] A typical standard for electrical communication connections or pulse-width modeled signals is specified in the IEC 61851-1 standard. This standard sets precise specifications regarding the tolerances of various signal parameters. According to the standard, a negative and a positive voltage level, as well as certain rise and fall times of the signal or its pulses, must be maintained.

[0004] Such a conventional electric charging station is usually electrically connected to the electric vehicle to be charged by means of an electrical connecting cable. The longer the connecting cable, the higher its electrical resistance, capacitance and inductance. With these values, the connecting cable usually acts as a low-pass filter, so that components of the electrical signal with high frequencies are attenuated to a greater extent by the connecting cable. An electrical square-wave signal proposed in accordance with the IEC 61851 standard contains a broad spectrum of frequencies, which also includes higher-frequency components, with these high frequencies of the spectrum being primarily responsible for the edges of the electrical square-wave signal. The steeper the edge, the greater the high-frequency component of the signal typically needs to be.

[0005] If the signal is now sent via the connecting cable, these high frequencies of the square-wave signal spectrum are disadvantageously filtered in conventional charging devices, resulting in a reduction in the edge steepness across the connecting cable. Depending on the length and quality of the connecting cable, the edge steepness can decrease so drastically that it falls outside the standardized target range. This can have the disadvantage that electric vehicles that strictly comply with the IEC 61851 standard will not be charged with electrical energy when electrically connected to the charging device if the quality of the connecting cable causes the signal to deviate from the standard.US 2014 / 247893 A1 discloses an electronic circuit arrangement for an electric charging station, wherein the circuit arrangement can be used to establish an electrical communication connection between the electric charging station and an electric vehicle that can be charged with electrical energy by means of the charging station. The circuit arrangement includes an electrical pilot contact and an electrical ground contact, to which the electric vehicle can be electrically connected to form the electrical communication connection, and an electrical conduction path in which an electrical oscillator is arranged. EP 2 197 084 A1 discloses an electronic circuit arrangement for an electric charging station, wherein the circuit arrangement can be used to establish an electrical communication connection between the charging station and an electric vehicle according to the prior art.

[0006] It is therefore an object of the present invention to provide an electronic circuit arrangement for an electric charging station and a method for designing an electrical frequency filter device of such a circuit arrangement, which takes the above-mentioned problem into account.

[0007] This object is achieved by the subject matter of independent claim 1 and the method of independent claim 2. Preferred embodiments are the subject matter of the dependent claims.

[0008] The basic idea of the invention is therefore to equip an electronic circuit arrangement for an electronic charging station, wherein the circuit arrangement can be used to establish an electrical communication connection between the electric charging station and an electric vehicle that can be charged with electrical energy by means of the charging station, with a frequency filter device that attenuates high-frequency components of an electrical signal transmitted via the communication connection less than low-frequency components of the signal. The frequency filter device can be designed using a method according to the invention, which is based on the general idea of designing the frequency filter device depending on the nature of an electrical connection cable of the charging station or the circuit arrangement of the charging station.

[0009] Such a frequency filter device or such a design of the frequency filter device can advantageously counteract the frequency filtering effect of the electrical connection cable described above. This can better ensure compliance with the IEC 61851 standard.

[0010] An electronic circuit arrangement according to the invention for an electric charging station, wherein the circuit arrangement can be used to establish an electrical communication connection between the electric charging station and an electric vehicle that can be charged with electrical energy by means of the charging station, comprises an electrical pilot contact and an electrical ground contact. Two pilot contacts can be provided, namely a so-called "proximity pilot contact" and a so-called "control pilot contact," whereby the pilot contact in the context of the present application preferably refers to the control pilot contact. The electric vehicle can be electrically connected to the pilot contact and the ground contact to establish the electrical communication connection.The electronic circuit arrangement further comprises an electrical conduction path in which an electrical oscillator is arranged for generating a pulse-width-modulated electrical communication signal. The oscillator can be a pulse-width modulator acting as a signal source. The oscillator divides the conduction path into at least a pilot section ending in the pilot contact, remote from the oscillator, and a ground section ending in the ground contact, remote from the oscillator. An electrical parallel conduction path of the circuit arrangement, in which an electrical capacitance is arranged, is electrically connected to the pilot section and to the ground section, parallel to the oscillator. The electrical ground section can be electrically grounded. The electrical capacitance in the parallel conduction path can be part of a low-pass filter of the electronic circuit arrangement.In this case, a frequency filter device, which can be parameterized in particular, is arranged in the pilot section of the electrical conduction path for filtering the electrical communication signal. In the pilot section, an electrical voltage measuring device, by means of which an electrical voltage present between the pilot contact and the ground contact can be measured, is electrically connected to the electrical conduction path between the pilot contact and the frequency filter device. As already indicated above, the frequency filter device of the electronic circuit arrangement according to the invention can advantageously counteract the undesirable frequency filter effect of the electrical connecting cable, so that compliance with the standardized specifications with regard to the electrical communication connection can be better ensured.

[0011] The invention further relates to a method for designing an electrical frequency filter device of the above-described electronic circuit arrangement according to the invention. According to the method, the frequency filter device is parameterized depending on the nature, in particular the electrical impedance, of an electrical connecting line that defines the pilot section and the ground section of the electrical conduction path at least in part. The nature of the connecting line is or will be defined at least by a selection of a length of the electrical connecting line, an electrical resistance value of the connecting line, an electrical capacitance value of the connecting line, and an electrical inductance value of the connecting line.The method according to the invention advantageously allows the above-described advantages of the electronic circuit arrangement according to the invention with the frequency filter device designed by means of the method to be exploited to a particularly large extent - even if different electrical connection cables are used at charging stations of the same type.

[0012] When performing the procedure, the quality of the connecting cable is determined. This allows the frequency filter device to be tuned with particular precision to the quality of the specific connecting cable used.

[0013] According to a preferred development of the method, the connecting cable defines the pilot section and the ground section of the electrical conduction path in a region located outside a housing interior defined by a housing of the electric charging station. The frequency filter device, the oscillator, the capacitor, and a remaining region of the electrical conduction path located away from the connecting cable are arranged in the housing interior. The region in which the connecting cable defines the pilot and ground sections of the electrical conduction path can be formed by a cable with two electrically insulated strands for the pilot and ground sections. Thus, the properties of such a cable can be taken into account for the design of the frequency filter device using the method in this development.This proves to be particularly advantageous when different cables are used selectively, especially with regard to their length or other properties.

[0014] In a further advantageous development of the method, the frequency filter device has an electrical filter resistance value, an electrical filter capacitance value, and an electrical filter inductance value, each of which can be parameterized to be equal to or greater than zero. The filter resistance value can thus be parameterized to be equal to or greater than 0 ohms. The filter capacitance value can be parameterized to be equal to or greater than 0 farads. The filter inductance value can be parameterized to be equal to or greater than 0 henries.The frequency filter device is parameterized using a value table in which incremental quality values for at least one selected from the length of the electrical connecting line, the electrical resistance value of the connecting line, the electrical capacitance value of the connecting line, and the electrical inductance value of the connecting line are assigned, in particular in a clustered manner, to incremental parameter values for the electrical filter resistance value, the electrical filter capacitance value, and the electrical filter inductance value. Such a design of the frequency filter device is particularly easy to implement technically.

[0015] It is advisable to electrically short-circuit the pilot and ground contacts when determining the condition of the connecting cable. This allows the condition of the connecting cable to be determined for both the pilot and ground sections in one go.

[0016] In an advantageous development of the method, an electrical measuring resistor with a predetermined measuring resistance value is electrically connected in series with the pilot section of the electrical conduction path. A constant electrical voltage of a predetermined voltage value is then generated using an electrical voltage source and applied to the pilot section and the ground section at a common end of the connecting line facing away from the pilot contact and the ground contact. A voltage value of the electrical voltage drop across the measuring resistor is measured. Finally, the quality of the connecting line is determined at least by the electrical resistance value of the connecting line, which is calculated from the voltage values of the predetermined constant electrical voltage and the measured electrical voltage drop across the measuring resistor. The quality of the connecting line can therefore advantageously be determined particularly precisely.

[0017] In another preferred development of the method, a constant electric current of predetermined current intensity is generated by means of an electric current source and applied to the pilot section and the ground section at a common end of the connecting line facing away from the pilot contact and the ground contact. A voltage value of the electrical voltage drop across the pilot section and the ground section is measured. The quality of the connecting line is determined at least by the electrical resistance value of the connecting line, which is calculated from the predetermined current intensity and the measured voltage value of the electrical voltage drop across the pilot section and the ground section. This also allows a particularly precise determination of the quality of the connecting line.

[0018] According to a further preferred development of the method, the quality of the connecting cable is additionally determined at least by the length of the connecting cable. The length of the connecting cable is calculated from a predetermined electrical resistance per unit length of the connecting cable and the calculated electrical resistance value of the connecting cable. This allows the quality of the connecting cable to be determined even more precisely.

[0019] In another advantageous development of the method, the quality of the connecting line is determined at least by the length of the connecting line. An electrical voltage pulse source generates an electrical voltage pulse and sends it from an end of the connecting line facing away from the pilot contact through the area of the pilot section present in the connecting line, whereby the pilot contact is exposed. The voltage pulse is reflected at the pilot contact. The reflected voltage pulse is then detected at the end of the connecting line facing away from the pilot contact. In this process, a propagation time between generation of the voltage pulse and detection of the reflected voltage pulse is measured. Finally, the length of the connecting line is calculated based on a predetermined propagation speed of electrical voltage on the connecting line and the measured propagation time.This makes it advantageous to determine the condition of the connecting cable without first having to electrically short-circuit the ground contact and pilot contact.

[0020] According to another advantageous development of the method, the quality of the connecting cable is determined at least by the electrical capacitance value of the connecting cable. The capacitance value of the connecting cable is measured. This also allows the quality of the connecting cable to be determined very precisely.

[0021] The circuit's frequency filtering device includes a high-pass filter and / or a band-pass filter. This allows the circuit to be even more accurately tuned for compliance with the IEC 61851 standard.

[0022] According to a further preferred development of the circuit arrangement, the frequency filter device can be configured or designed in analog and / or digital form, in particular parameterizable or parameterized. In a corresponding further advantageous development of the method, the frequency filter device is configured or designed in analog and / or digital form, in particular parameterized. This allows for a particularly simple, technically implemented design of the frequency filter device.

[0023] According to a further advantageous development of the circuit arrangement or method, the frequency filter device comprises precisely one electrical resistor and precisely one electrical capacitor, with the capacitor being electrically connected in parallel with the resistor. Such a frequency filter device proves to be particularly robust.

[0024] In summary, the invention relates to an electronic circuit arrangement for an electric charging station, with an electrical pilot contact and with an electrical ground contact, to which an electric motor vehicle can be electrically connected to form the electrical communication connection and with an electrical conduction path in which an electrical oscillator is arranged for generating a pulse-width modulated electrical communication signal, wherein the oscillator divides the electrical conduction path into a pilot section ending in the pilot contact and a ground section ending in the ground contact, wherein a frequency filter device is arranged in the pilot section of the electrical conduction path.

[0025] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0026] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0027] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0028] They show, schematically Fig. 1 in circuit diagram-like representation, an example of an electronic circuit arrangement according to the invention for an electric charging station, Fig. 2 another example of the electronic charging station according to the invention in a circuit diagram-like representation.

[0029] In the Figure 1An example of an electronic circuit arrangement 1 according to the invention for an electric charging station 20 is shown in circuit diagram form. By means of the circuit arrangement 1, an electrical communication connection 30 can be established between the electric charging station 20 - which in the example of the Figure 1the circuit arrangement 1 according to the invention - and an electric motor vehicle 31 that can be charged with electrical energy by means of the charging station 20. The electronic circuit arrangement 1 comprises an electrical pilot contact 2 and an electrical ground contact 3, to which the electric motor vehicle 31 can be electrically connected to form the electrical communication connection 30. In addition, the electronic circuit arrangement 1 has an electrical conduction path 4 in which an electrical oscillator 5 is arranged for generating a pulse-width-modulated electrical communication signal S. The oscillator 5 can therefore be a pulse-width modulator acting as a signal source. The communication signal S generated by the oscillator 5 can be transmitted from the charging station 20 to the electric vehicle 31 via the communication connection 30.The motor vehicle 31 can also send an electrical signal to the charging station 20 via the communication connection 30 if necessary.

[0030] The Figure 1It can further be seen that the oscillator 5 divides the electrical conduction path 4 into at least a pilot section 6 and a ground section 7 of the electrical conduction path 4. The ground section 7 can be electrically grounded. In this case, the pilot section 6 of the electrical conduction path 4 ends in the pilot contact 2, facing away from the oscillator 5. The ground section 7 of the electrical conduction path 4 ends in the ground contact 3, facing away from the oscillator 5. In addition, the electronic circuit arrangement 1 comprises an electrical parallel conduction path 8, in which an electrical capacitor CS is arranged. The electrical parallel conduction path 8 is electrically connected at one end to the pilot section 6 and at the other end to the ground section 7 of the electrical conduction path 4, forming an electrical parallel circuit of the electrical capacitor CS to the oscillator 5.

[0031] According to Figure 1In the pilot section 6 of the electrical conduction path 4, a frequency filter device 9 is arranged for filtering the electrical communication signal K. This frequency filter device 9 can be parameterized, so that by designing or parameterizing the frequency filter device 9, it can be set which frequencies of electrical voltage are attenuated by the frequency filter device 9 and to what extent. In the pilot section 6, an electrical voltage measuring device, by means of which an electrical voltage applied between the pilot and ground contacts 2, 3 can be measured, is also electrically connected to the electrical conduction path 4 between the pilot contact 2 and the frequency filter device 9. This voltage measuring device itself is in the Figure 1not shown; however, an arrow line tapering to the right schematically illustrates the routing of an electrical measuring line 14, by means of which the electrical voltage to be measured can be fed to the voltage measuring device.

[0032] The Figure 2 also shows in a circuit diagram-like representation a further example of the electronic circuit arrangement 1 according to the invention, which differs from that of Figure 1 differs only in the specific design of the frequency filter device 9. Whereas the frequency filter device 9 in the Figure 1 abstracted to a black box, the Figure 2 an embodiment of the electronic circuit arrangement 1 with a frequency filter device 9, which comprises a high-pass filter 13. According to Figure 2the frequency filter device 9 or its high-pass filter 13 comprises exactly one electrical resistor R1 and exactly one electrical capacitor C1, wherein the capacitor C1 is electrically connected in parallel with the electrical resistor R1.

[0033] The frequency filter device 9 of the example of Figure 1 can - alternatively for example the Figure 2 - a bandpass filter. However, the frequency filter device 9 can also comprise a combination of a high-pass filter 13 and a bandpass filter, with the high-pass filter and bandpass filter then acting together like a bandpass filter. The frequency filter device 9 can be configured, for example, in analog form or—alternatively or additionally—in digital form, and in particular can be parameterized.

[0034] The frequency filter devices 9 of the exemplary in the Figures 1 and 2The electronic circuit arrangements 1 shown are designed using a method according to the invention. According to this method, the frequency device 9 is parameterized depending on the nature of an electrical connecting line 10 that at least partially defines the pilot section 6 and the ground section 7 of the electrical conduction path 4. The nature of the connecting line 10 can be an electrical impedance of the electrical connecting line 14. The nature of the connecting line 10 is or will be defined by at least one selected from a length L of the electrical connecting line 10, an electrical resistance value RA of the electrical connecting line 10, an electrical capacitance value CA of the connecting line 10, and an electrical inductance value LA of the connecting line 10. The nature of the connecting line 10 is determined according to the method.The connecting cable 10 defines the pilot section 6 and the ground section 7 of the electrical conduction path 4 in a region 11 located outside a housing interior 2 and 20 delimited by a housing 21 of the electric charging station 20. The frequency filter device 9, the oscillator 5, the capacitor CS, and a remaining region 12 of the electrical conduction path 4 located away from the connecting cable 10 are arranged in the housing interior 22.

[0035] The frequency filter device 9 has an electrical filter resistance value RF, an electrical filter capacitance value CF, and an electrical inductance value LF. The filter resistance value RF, the filter capacitance value CF, and the inductance value LF can each be parameterized to be equal to or greater than zero. The filter resistance value RF can therefore be parameterized to be equal to or greater than 0 ohms. The filter capacitance value CF can be parameterized to be equal to or greater than 0 farads. The filter inductance value LF can be parameterized to be equal to or greater than 0 henries. For example, the frequency filter device is parameterized using a value table. In this value table, incremental quality values are assigned to incremental parameter values.The value table contains, for example, quality values for at least one selected from the length L of the electrical connecting cable 10, the electrical resistance value RA of the connecting cable 10, the electrical capacitance value CA of the electrical connecting cable 10, and the electrical inductance value of the connecting cable 10. For example, incremental parameter values for the electrical filter resistance value RF, the electrical filter capacitance value CF, and the electrical filter inductance value LF are stored in the value table.

[0036] In a first and a second variant of the method, the pilot and ground contacts 2, 3 are electrically short-circuited when determining the condition of the connecting cable 10.

[0037] According to the first variant of the method, an electrical measuring resistor with a predetermined measuring resistance value is electrically connected in series with the pilot section 2 of the electrical conduction path 4. A constant electrical voltage of a predetermined voltage value that remains constant over time is then generated by an electrical voltage source and applied to the pilot section 6 and the ground section 7 at a common end of the connecting line 10 facing away from the pilot contact 2 and the ground contact 3. A voltage value of the electrical voltage drop across the measuring resistor is measured.In this variant, the nature of the connecting line 10 is determined at least by the electrical resistance value RA of the connecting line 10, wherein the electrical resistance value RA of the connecting line 10 is calculated from the voltage values of the predetermined constant electrical voltage and the measured electrical voltage dropping across the measuring resistor.

[0038] The electrical resistance value RA of the connecting cable 10 can be calculated in the first variant of the method using the following formula A: RA = R bekannt * U Leitung U konstant − U Leitung where R is the electrical measuring resistance value, U constant is the electrical voltage value of the constant electrical voltage generated by the voltage source and U line is the difference between U constant and the voltage value of the voltage drop across the measuring resistance.

[0039] According to the second variant of the method, a constant electrical current of predetermined current intensity that is constant over time is generated by means of an electrical current source and applied to the pilot section 6 and the ground section 7 at the common end of the connecting line 10 facing away from the pilot contact 2 and the ground contact 3. In this process, a voltage value of the electrical voltage drop across the pilot section 6 and the ground section 7 is measured. In this variant, the nature of the connecting line 10 is determined at least by the electrical resistance value RA of the connecting line 10, wherein the electrical resistance value RA of the connecting line 10 is calculated from the predetermined current intensity and the measured voltage value of the electrical voltage drop across the pilot section 6 and the ground section 7.

[0040] The electrical resistance value RA of the connecting cable 10 can be calculated in the second variant of the method using the following formula B: RA = U Leitung I konstant where U line is the electrical voltage value of the electrical voltage dropped across the pilot section and the ground section and I constant is the electrical current intensity of the constant electrical current generated by the electrical current source.

[0041] In both the first and the second variant of the method, the nature of the connecting line 10 can additionally be determined at least by the length L of the connecting line 10. The length L of the connecting line 10 can be calculated from a predetermined electrical resistance R' of the connecting line 10 and the calculated electrical resistance value RA of the connecting line 10.

[0042] The calculation of the length L of the connecting cable RA can be carried out in the first and second variants of the method using the following formula B: L = RA R ′

[0043] The resistance per unit length R' of the connecting cable 10 can be predetermined in advance based on measurements or from a data sheet or relevant reference books for the method. A prior measurement of the resistance per unit length R' on a sample of the connecting cable 10 of known length may prove advantageous, as this allows contact resistances to be directly taken into account in the measurement result.

[0044] In a third variant of the method, the nature of the connecting line 10 is determined at least by the length L of the connecting line 10. In this case, an electrical voltage pulse is generated using an electrical voltage pulse source and sent from an end of the connecting line 10 facing away from the pilot contact 2 through the area 11 of the pilot section 6 present in the connecting line 10, whereby the pilot contact 2 is exposed. The voltage pulse is reflected at the pilot contact 2. The reflected voltage pulse is detected at the end of the connecting line 10 facing away from the pilot contact 2. In this case, a propagation time between the generation of the voltage pulse and the detection of the reflected voltage pulse is measured. The length L of the connecting line 10 is then calculated based on a predetermined propagation speed c of electrical voltage on the connecting line 10 and the measured propagation time.

[0045] According to a fourth variant of the method, the quality of the connecting cable 10 is determined at least by the electrical capacitance value CA of the connecting cable 10. The capacitance value CA of the connecting cable 10 is measured.

[0046] In all variants of the method, the frequency filter device 9 can be designed, for example parameterized, in analogue or - alternatively or additionally - digital form.

Claims

1. An electronic circuit arrangement (1) for an electric charging station (20), wherein an electrical communication connection (30) can be formed, by means of the circuit arrangement (1), between the electric charging station (20) and an electric motor vehicle (31) which can be charged with electrical energy by means of the charging station (20), - having an electrical pilot contact (2) and having an electrical earth contact (3), to which the electric motor vehicle (31) can be electrically connected to form the electrical communication connection (30), - having an electrical line path (4) in which an electrical oscillator (5) is arranged, - wherein the oscillator (5) divides the electrical line path (4) at least into a pilot portion (6) ending in the pilot contact (2) facing away from the oscillator (5) and into an earth portion (7) ending in the earth contact (3) facing away from the oscillator (5), - wherein an electrical parallel line path (8), in which an electrical capacitor (CS) is arranged, is electrically connected to the pilot portion (6) and to the earth portion (7) in parallel with the oscillator (5), wherein - the electrical oscillator (5) is designed to generate a pulse-width modulated electrical communication signal (S), and wherein - a parameterizable frequency filter device (9) for filtering the electrical communication signal (K) is arranged in the pilot portion (6) of the electrical line path (4); and wherein - in the pilot portion (6), an electrical voltage-measuring device, by means of which an electrical voltage applied between the pilot contact and earth contact (2, 3) can be measured, is electrically connected to the electrical line path (4) between the pilot contact (2) and parameterizable frequency filter device (9); and wherein - the frequency filter device (9) comprises a high-pass filter (13) and / or a band-pass filter and can be parameterized depending on the quality, in particular the electrical impedance, of an electrical connecting line (10) which defines the pilot portion (6) and the earth portion (7) of the electrical line path (4) at least in some regions, wherein the quality of the connecting line (10) is defined at least by one selected from a length (L) of the electrical connecting line (10), an electrical resistance value (RA) of the connecting line (10), an electrical capacitance value (CA) of the connecting line (10) and an electrical inductance value (LA) of the connecting line (10).

2. A method for designing an electrical frequency filter device (9) of the electronic circuit arrangement (1) according to claim 1, according to which - the frequency filter device (9) is parameterized depending on the quality, in particular the electrical impedance, of an electrical connecting line (10) which defines the pilot portion (6) and the earth portion (7) of the electrical line path (4) at least in some regions, - the quality of the connecting line (10) is determined at least by one selected from a length (L) of the electrical connecting line (10), an electrical resistance value (RA) of the connecting line (10), an electrical capacitance value (CA) of the connecting line (10) and an electrical inductance value (LA) of the connecting line (10).

3. The method according to claim 2, characterized in that the nature of the connecting line (10) is determined according to the method.

4. The method according to claim 2 or 3, characterized in that - the connecting line (10) defines the pilot portion (6) and the earth portion (7) of the electrical line path (4) in a region (11) which is located outside a housing interior (22) delimited by a housing (21) of the electric charging station (20), - the frequency filter device (9), the oscillator (5), the capacitor (CS) and a residual region (12) of the electrical line path (4) located away from the connecting line (10) being arranged in the housing interior (22).

5. The method according to any of claims 2 to 4, characterized in that - the frequency filter device (9) has an electrical filter resistance value (RF) and an electrical filter capacitance value (CF) and an electrical filter inductance value (LF), which can each be parameterized to be equal to or greater than zero, - the frequency filter device (9) is parameterized using a value table in which incremental quality values for at least one selected from the length (L) of the electrical connecting line (10), the electrical resistance value (RA) of the connecting line (10), the electrical capacitance value (CA) of the connecting line (10) and the electrical inductance value (LA) of the connecting line (10) are assigned incremental parameter values for the electrical filter resistance value (RF) and the electrical filter capacitance value (CF) and the electrical filter inductance value (LF).

6. The method according to any of claims 2 to 5, characterized in that the pilot contact and the earth contact (2, 3) are electrically short-circuited when determining the quality of the connecting line (10).

7. The method according to claim 6, characterized in that - an electrical measuring resistor having a predetermined measuring resistance value is electrically connected in series with the pilot portion (2) of the electrical line path (4), - a constant electrical voltage of a predetermined voltage value is generated by means of an electrical voltage source and is applied to the pilot portion (6) and the earth portion (7) at a common end of the connecting line (10) facing away from the pilot contact (2) and the earth contact (3), - a voltage value of the electrical voltage dropping across the measuring resistor is measured, - the quality of the connecting line (10) is determined at least by the electrical resistance value (RA) of the connecting line (10), which is calculated from the voltage values of the predetermined constant electrical voltage and the measured electrical voltage dropping across the measuring resistor.

8. The method according to claim 6, characterized in that - a constant electrical current of predetermined current intensity is generated by means of an electrical current source and is applied to the pilot portion (6) and the earth portion (7) at a common end of the connecting line (10) facing away from the pilot contact (2) and the earth contact (3), - a voltage value of the electrical voltage dropping across the pilot portion (6) and the earth portion (7) is measured, - the quality of the connecting line (10) is determined at least by the electrical resistance value (RA) of the connecting line (10), which is calculated from the predetermined current intensity and the measured voltage value of the electrical voltage dropping across the pilot portion (6) and the earth portion (7).

9. The method according to claim 7 or 8, characterized in that - the quality of the connecting line (10) is additionally determined at least by the length (L) of the connecting line (10), - the length (L) of the connecting line (10) is calculated from a predetermined electrical resistance load per unit length (R') of the connecting line (10) and the calculated electrical resistance value (RA) of the connecting line (10).

10. The method according to any of claims 2 to 5, characterized in that - the quality of the connecting line (10) is determined at least by the length (L) of the connecting line (10), - an electrical voltage pulse is generated by means of an electrical voltage pulse source and is sent from an end of the connecting line (10) facing away from the pilot contact (2) through the region (11) of the pilot portion (6) located in the connecting line (10), the pilot contact (2) being exposed - the voltage pulse is reflected at the pilot contact (2), - the reflected voltage pulse is detected at the end of the connecting line (10) facing away from the pilot contact (2), - a transit time between generating the voltage pulse and detecting the reflected voltage pulse is measured, - the length (L) of the connecting line (10) is calculated using a predetermined propagation speed (c) of electrical voltage on the connecting line (10) and the measured transit time.

11. The method according to any of claims 2 to 5, characterized in that - the quality of the connecting line (10) is determined at least by the electrical capacitance value (CA) of the connecting line (10), - the capacitance value (CA) of the connecting line (10) is measured.

12. The circuit arrangement (1) according to claim 1, characterized in that the frequency filter device (9) can be or is designed to be analogue and / or digital, in particular can be or is parameterized.

13. The circuit arrangement (1) according to claim 1 or 12, characterized in that the frequency filter device (9) comprises exactly one electrical resistor (R1) and exactly one electrical capacitor (C1), the capacitor (C1) being electrically connected in parallel to the resistor (R1).