Determining at least one interference frequency from at least one ac voltage or an alternating current of an electrical energy supply network
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-08
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026050243_13082026_PF_FP_ABST
Abstract
Description
[0001] 202422688 Foreign version
[0002] 1
[0003] Description
[0004] Determining at least one interference frequency of at least one alternating voltage or alternating current of an electrical power supply network.
[0005] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.
[0006] The invention relates to an application of a method for determining at least one disturbance frequency of at least one alternating voltage or alternating current of an electrical power supply network in a switchgear assembly which has a plurality of outputs for consumers and / or electrical power generators, wherein the alternating voltage or alternating current has a fundamental frequency, wherein the alternating voltage or alternating current is detected by means of a sensor unit and the sensor unit provides a sensor signal, wherein the sensor signal is evaluated by means of an evaluation unit in order to determine the at least one disturbance frequency.The invention further relates to a switchgear assembly having a plurality of outputs for consumers and / or electrical power generators, with a diagnostic device for determining at least one disturbance frequency of at least one alternating voltage or alternating current of an electrical power supply network, wherein the alternating voltage or alternating current has a fundamental frequency, wherein the diagnostic device has a sensor connection for connecting a sensor unit for detecting the alternating voltage or alternating current and for providing a sensor signal, and an evaluation unit connected to the sensor connection for evaluating the sensor signal in order to determine the at least one disturbance frequency.
[0007] Typical methods and switchgear are extensively known in the prior art, so that, in principle, a separate printed document is not required. Switchgear is an electrical installation used for the distribution of electrical energy in an electrical power supply network to which electrical consumers and / or electrical power generators are connected. For the purpose of energy distribution, the switchgear typically includes several electrical switches, which are often designed as electromechanical switches. Such switches can be, for example, disconnectors, load switches, circuit breakers, or the like. The electrical switchgear and its components are subject to standardization, such as EN 61439 for switchgear in the low-voltage range, among others. In this context, [202422688 foreign version]
[0008] 2
[0009] Low voltage refers to an electrical voltage as defined in Directive 2014 / 35 / EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits (Low Voltage Directive). Other standards may apply, among others, to consumers or electrical power producers, such as the European EMC Directive 2014 / 13 / EU or others.
[0010] An electrical power supply network, such as the public power supply network, can connect a large number of consumers and / or electrical power generators, particularly in the low-voltage range. These consumers and power generators are typically electrically coupled to one another via at least one electrical switchgear assembly. Furthermore, the electrical coupling may also include one or more transformers. The electrical switchgear assembly usually has at least one output with an electrical switch for one, or occasionally several, parallel-connected electrical consumers or power generators, allowing the electrical coupling to be established or broken as needed.For this purpose, the switch is operated in a switching state in which it can assume at least two different switching states, namely at least one switched-on state and one switched-off state.
[0011] To ensure reliable electrical power distribution, electrical consumers and / or electrical power generators must meet certain requirements regarding network feedback, such as those defined by the European EMC Directive 2014 / 30 / EU. This is intended to prevent mutual interference between consumers or electrical power generators connected to the electrical power supply network, particularly the electrical switchgear, thus ensuring the uninterrupted operation of all consumers and electrical power generators.
[0012] Nevertheless, mutual interference cannot always be completely avoided when the electrical power supply network is used as intended. For example, a fault may occur at a consumer or an electrical power generator, for instance in a component of the consumer or the electrical power generator, which may undesirably cause feedback into the network.
[0013] 3
[0014] This can cause problems in the energy distribution network. This feedback loop can affect other consumers or electrical power generators, leading to malfunctions. For example, a defective power supply in a printer in an office can prevent a production machine in a factory hall far from the office from operating as intended. It can be particularly problematic if the fault is not detected at its source, preventing timely remediation.
[0015] To detect such disturbances and identify their source, it has proven useful to monitor alternating current and / or voltage in the switchgear when the electrical power supply network operates on alternating current. For this purpose, it is already common practice to monitor spectral behavior, particularly with regard to specific frequencies, at key points in the electrical power distribution system. Appropriate sensor units can be provided for this purpose, which may, for example, be located in a switchgear assembly. In contrast, simple monitoring devices are typically connected to outgoing circuits, especially those to which individual consumers and / or electrical power generators are connected. These devices generally do not allow for spectral monitoring of the alternating voltage or current.In the case of a problem like the one described above, the state of the art therefore typically involves manually tracing the fault from output to output using a suitable measuring device, from output to output until the output through which the fault is coupled into the electrical power supply network. This is labor-intensive, expensive, and requires complex expert knowledge. The measuring devices typically present in a switchgear assembly often cannot be used because they lack the specific functionality required for this purpose.
[0016] The invention is based on the objective of improving, with the least possible effort, at least one interference frequency that disrupts the intended operation of the electrical power supply network and connected consumers and electrical power generators.
[0017] The invention proposes as a solution an application of a method for determining at least one interference frequency in a switchgear assembly and a switchgear assembly.
[0018] Advantageous further training opportunities arise from the characteristics of the dependent claims. 202422688 Foreign version
[0019] 4
[0020] With regard to a generic application of the method, the invention particularly proposes that for evaluation by the evaluation unit, a frequency range is specified in which the at least one disturbance frequency is expected, wherein a lower frequency limit of the frequency range is greater than the fundamental frequency, the sensor signal is sampled in a time-discrete manner over a specified number of periods of the fundamental frequency at a specified data rate in order to obtain a specified number of samples, a Fourier transform is applied to a specified first part of the number of samples to determine a first phase, the Fourier transform is applied to a specified second part of the number of samples to determine a second phase, wherein the second part is different from the first part, and the at least one disturbance frequency is determined at least as a function of the first and the second phase.The method automatically checks the outputs with regard to the origin of the at least one interference frequency, narrows down the origin of the at least one interference frequency, and identifies an interference source that causes the at least one interference frequency.
[0021] With regard to a generic switching system with a diagnostic device, the invention particularly proposes that the diagnostic device has a preset connection for receiving data specifying a frequency range in which at least one interference frequency is expected, wherein a lower frequency limit of the frequency range is greater than the fundamental frequency, wherein the evaluation unit is configured to sample the sensor signal over a predetermined number of periods of the fundamental frequency at a predetermined data rate in a time-discrete manner in order to obtain a predetermined number of samples, to apply a Fourier transform to a predetermined first part of the number of samples in order to determine a first phase, and to apply the Fourier transform to a predetermined second part of the number of samples in order to determine a second phase, wherein the second part is different from the first part.and to determine at least one interference frequency, at least as a function of the first and second phases. The method automatically checks the outputs with respect to the origin of the at least one interference frequency, narrows down the origin of the at least one interference frequency, and identifies an interference source causing the at least one interference frequency.
[0022] The invention is based, among other things, on the idea that by providing a triggerable analysis function via the diagnostic device, manual measurement and analysis of frequencies can be reduced or even completely avoided. A disturbance frequency identified as essentially known can thus be quickly and easily identified.
[0023] 5
[0024] Identifying the source of the interference requires considerable effort. The invention utilizes, among other things, findings already obtained through frequency analysis of music, as described in a technical article by Judith C. Braun and Miller S. Puckette, "A high resolution fundamental frequency determination based on phase changes of the Fourier transform," J. Acoust. Soc. Am. 94 (2), Part 1, August 1993, beginning on page 662. The frequency range for the analysis can be predefined, for example, by manual input from a user via an input unit. Furthermore, a communication interface can be provided, which connects to an external communication device through which at least one interference frequency can be transmitted.The communication device can be, for example, a user terminal device such as a smartphone, a tablet computer, or the like.
[0025] With regard to the electrical power supply network, it is no longer necessary to manually check all branches or outputs of the network for the origin of at least one interference frequency. Instead, this process can be at least partially automated. This not only saves time and resources but also allows for a relatively quick identification of the source of the interference frequency. This enables the rapid identification of the source of the interference frequency, allowing for timely remediation. The reliability of the power supply network's operation, as well as that of connected consumers and / or electrical power generators, can thus be further improved. Overall, the reliability of the intended use of the electrical power supply network can also be enhanced.
[0026] Alternating voltage can be single-phase or multi-phase, especially three-phase. The fundamental frequency of alternating voltage in a public power grid can be, for example, around 50 Hz or around 60 Hz. This also applies, in principle, to alternating current.
[0027] The alternating current or voltage can be detected by the sensor unit. The sensor unit is designed to detect the alternating voltage or current and provide a corresponding sensor signal. If the alternating voltage or current is multiphase, the sensor signal can be adjusted accordingly.
[0028] 6
[0029] be implemented and have corresponding partial sensor signals, whereby each partial sensor signal can be assigned to a respective phase of the alternating voltage or alternating current.
[0030] The sensor unit is coupled to the evaluation unit via a signal connection, enabling the evaluation unit to process the sensor signal. The evaluation unit is designed to determine at least one interference frequency by analyzing the sensor signal. For this purpose, a frequency range is specified for evaluation by the unit, within which at least one interference frequency is expected. This frequency range can be specified manually by a user at an input unit or user interface. Alternatively, the frequency range can be transmitted to the evaluation unit from a remote location, such as a central control room, via a communication link and a communication interface. The frequency range is typically defined such that a lower frequency limit is higher than the fundamental frequency.The number of periods of the fundamental frequency used for evaluation can also be specified manually, for example via the communication device, or by a remote control center.
[0031] The evaluation unit may, in particular, comprise one or more computing units, one or more microcontrollers, and / or one or more integrated circuits, for example, one or more application-specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), and / or one or more systems-on-a-chip (SoCs). The evaluation unit may also include one or more processors, for example, one or more microprocessors, one or more central processing units (CPUs), one or more graphics processing units (GPUs), and / or one or more signal processors, in particular one or more digital signal processors (DSPs). The evaluation unit may also include one or more hardware and / or software interfaces, for example, for receiving and / or providing data.
[0032] The evaluation unit can also include one or more storage devices. A storage device can be implemented as volatile memory, for example as dynamic random-access memory (DRAM) or static random-access memory (SRAM), or as non-volatile data storage, for example as read-only memory (ROM), programmable read-only memory (PROM), or erasable memory.
[0033] programmable read-only memory, EPROM, as electrically erasable programmable read-only memory, EEPROM, as flash memory or as flash EEPROM, as ferroelectric random access memory, FRAM, as magnetoresistive random access memory, MRAM, or as phase-change random access memory, PCRAM.
[0034] The evaluation unit samples the sensor signal over a predetermined number of periods of the fundamental frequency at a predetermined data rate. The data rate can be fixed, manually adjusted, predefined, or set by a central unit. The data rate is preferably at least twice the expected interference frequency, and preferably more than twice the upper frequency limit of the frequency range. For example, with a fundamental frequency of approximately 50 Hz or 60 Hz, an interference frequency in the range between 700 Hz and 1000 Hz can be expected. In such a case, the data rate can preferably be chosen to be greater than 2 kHz. Preferably, the data rate can be approximately 4 kHz, allowing the use of commercially available sampling units.
[0035] From a given number of samples, the evaluation unit selects a predetermined first subset of the samples. A Fourier transform is then applied to this first subset to determine the first phase. The Fourier transform can be implemented as a discrete Fourier transform (DFT), particularly a fast Fourier transform (FFT). In this way, the evaluation unit can numerically determine the first phase. The evaluation unit can incorporate suitable hardware circuitry and / or a program-controlled computer unit operated by a suitably adapted computer program.
[0036] Furthermore, if necessary, a weighting function or a window function can be applied to the sampled values during the transformation process, for example a von Hann function, also called a Hanning function, which is defined as follows:
[0037]
[0038] where N1 is the number of samples from the first part. 202422688 Foreign version
[0039] Within the specified frequency range, the spectral analysis is performed. The nominal frequency under investigation is then scaled to the k-th multiple of the fundamental frequency, in this case the mains frequency f. Ne tz of the public energy supply network, defined and expressed as a frequency multiple f p designated, where:
[0040] fp fNetz
[0041] Using the von Hann function, a first transform Y1 can be determined using the discrete Fourier transform as follows:
[0042]
[0043] where x n the sample values are and f s the data rate is.
[0044] A Fourier transform is also applied to a predetermined second part of the sample set to determine a second phase. This second part differs from the first. That is, while the number of samples can be the same for both parts, the samples of the first part can be shifted from those of the second part by at least one sample. Depending on the requirements, this shift can involve one or more samples. It may also be necessary to choose a different number of samples for the first part than for the second part. The second transform, Y2, can be determined as follows:
[0045]
[0046] where x mwhere N2 is the number of samples and N2 is the number of samples of the second part.
[0047] After the evaluation unit has determined the first and second phases, it can identify at least one interference frequency based on these phases. The evaluation unit can use the following mathematical relationship for this purpose: 202422688 Foreign version
[0048] 9
[0049] f f larg (72) - arg (71) |
[0050] 2n
[0051] where f is the interference frequency.
[0052] As explained in the aforementioned technical article, it is thus possible to determine at least one interference frequency in a simple manner with comparatively little effort. The method according to the invention proves particularly advantageous when used in a switchgear assembly that has multiple outputs for consumers and / or electrical power generators. For example, it is possible to provide a corresponding procedure for each or at least some of the outputs by installing appropriate diagnostic devices. The diagnostic device can be implemented as a compact, simple, and cost-effective unit. It can therefore be easily integrated into existing, simple power monitoring devices that are also used in switchgear assemblies.This makes it possible to actively involve such simple power monitoring devices (PMDs) in the detection of interference frequencies, so that interruptions or downtimes and the like in relation to the intended operation of the electrical power supply network can be reduced or even avoided.
[0053] The method according to the invention can be particularly advantageously implemented in controls for switches, in particular load switches, disconnect switches, circuit breakers or the like, so that the analysis functionality with regard to the source of the at least one disturbance frequency can be improved in a simple way.
[0054] It is proposed that the number of samples for the first and second parts be the same, wherein the predetermined number of samples for the second part is shifted relative to the number of samples for the first part by at least one predetermined shift number. In this case, the shift number is preferably a natural number of at least 1. This allows the first and second phases to be reliably determined and processed particularly efficiently by the evaluation unit.
[0055] According to further training, it is suggested that the frequency range be set manually. This allows for simple adjustment of the frequency range. The setting can be made, for example, via a corresponding user interface on the diagnostic device. Furthermore, it is [202422688 foreign version]
[0056] 10
[0057] It is of course also possible that the frequency range is predetermined as an alternative or supplementary measure during the manufacture of the diagnostic device, for example by storing it in a memory unit of the diagnostic device.
[0058] It is further proposed that the frequency range be specified by a predefined unit, which defines the frequency range based on a captured spectrum relative to a predefined envelope. This allows the predefined unit to automate the frequency range definition process, for example, by determining the frequency range based on spectrum amplitudes that exceed the envelope. The predefined unit could be a separate unit, for example, one that is connected to all diagnostic devices in a switchgear system and configures these devices with respect to the frequency range. Alternatively, the predefined unit could be an external entity, particularly a central one, that configures or defines the corresponding frequency range for the diagnostic devices.
[0059] It is further proposed that the process be repeated automatically, specifying a modified frequency range. This further development makes it possible to apply the inventive method over large frequency ranges, particularly when multiple interference frequencies are expected. This proves especially advantageous when several interference frequencies are caused by different sources. It can also be provided that the process is repeated at predetermined times or depending on specific events, such as a fault report from a consumer or the like.
[0060] Furthermore, it is proposed that a window function be used when transforming the sampled values using the Fourier transform. In digital signal processing, the window function determines the weighting of the sampled values obtained during signal sampling within the predefined processing window for subsequent calculations. Examples of window functions include the rectangular window function, the von Hann window function, the Hamming window function, and others.
[0061] The advantages and effects stated for the application of the method according to the invention also apply equally to the switchgear according to the invention and vice versa. 202422688 Foreign version
[0062] 11
[0063] Therefore, process characteristics can also be formulated as device characteristics and vice versa.
[0064] The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combination specified but also in other combinations without leaving the scope of the invention.
[0065] The embodiments described below are preferred embodiments of the invention. The features and combinations of features specified above in the description, as well as those mentioned in the following description of embodiments and / or shown individually in the figures, are not only usable in the combinations specified, but also in other combinations. Thus, embodiments are also encompassed by the invention or are considered disclosed that are not explicitly shown and explained in the figures, but can be derived and generated from the described embodiments by separate combinations of features.The features, functions, and / or effects illustrated by the exemplary embodiments can each, considered independently, represent individual features, functions, and / or effects of the invention, each of which further develops the invention independently. Therefore, the exemplary embodiments are intended to include combinations other than those described in the embodiments. Furthermore, the described embodiments can also be supplemented by additional features, functions, and / or effects of the invention already described.
[0066] In the figures, the same reference symbols denote the same features or functions.
[0067] They show:
[0068] FIG 1 a schematic block diagram of a power supply network with a low-voltage switchgear assembly having circuit breakers for outgoing circuits and diagnostic equipment, 202422688 Foreign version
[0069] 12
[0070] FIG 2 shows a schematic block diagram of a diagnostic device connected to a current sensor unit according to FIG 1, and
[0071] FIG 3 shows a schematic flowchart for determining a disturbance frequency in the power supply network according to FIG 1.
[0072] FIG 1 shows a schematic block diagram of a power supply network 12 with a subnetwork 58 and a low-voltage switchgear 10. In this configuration, the power supply network 12 is designed as a low-voltage power supply network and, furthermore, as a power supply network that uses three-phase alternating voltage. The power supply network 12 has a subnetwork 58 to which the low-voltage switchgear 10 is connected. The power supply network 12 serves to distribute electrical energy.
[0073] The electrical switchgear 10 has outputs 14, 16, 18, 20, 22, and 24, which can be connected to the subnetwork 58 via respective circuit breakers 26, depending on their respective switching states. An electrical load 28 is connected to each of the outputs 14 to 24. In the present embodiment, the electrical loads 28 are intended to consume only electrical energy supplied via the subnetwork 58 and the low-voltage switchgear 10. Alternative embodiments may, of course, also provide for the connection of an electrical energy generator instead of at least one of the loads 28, for example, a solar power system, a wind turbine, an internal combustion engine-driven electric generator, and / or the like.
[0074] The electrical consumers 28 can be, for example, manufacturing machines, electric heating equipment, office equipment, lighting equipment and / or the like.
[0075] Each of the outputs 14 to 24 is equipped with a combination of a diagnostic device 34, 36, 38, 40, 42, 44 in conjunction with a current sensor unit 30. The current sensor unit 30 is configured to detect the electrical currents of the respective phases of the respective outputs 14 to 24 and, depending on this, to provide corresponding current sensor signals. For this purpose, the current sensor units 30 are electrically connected to the respective sensor terminals 56 of the respective diagnostic devices 34 to 44. The diagnostic devices 34 to 44 can then process the respective sensor signals.
[0076] 13
[0077] The data will be evaluated in order to determine at least one interference frequency, as will be explained in more detail below.
[0078] FIG. 2 shows, in a schematic block diagram, an example of output 14 with a diagnostic device 34 connected to a current sensor unit 30. A corresponding configuration is provided for the other outputs. In this embodiment, the current sensor unit 30 is designed separately from the diagnostic device 34. However, in alternative embodiments, the current sensor unit 30 can also be formed integrally with the diagnostic device 34, so that the diagnostic device 34 includes the current sensor unit 30.
[0079] The diagnostic device 34 serves to determine at least one interference frequency. In the present embodiment, the interference frequency is determined with respect to an alternating current. However, it can also be provided that an alternating voltage is used as the basis for determining the at least one interference frequency.
[0080] Diagnostic device 34 is explained below as an example. The other diagnostic devices 36, 38, 40, 42, and 44 are essentially identical in design.
[0081] The diagnostic device 34 has a preset unit 52 that specifies a frequency range in which at least one interference frequency f is expected. A lower frequency limit of the frequency range is greater than a fundamental frequency of the detected electric current. The fundamental frequency of the electric current corresponds to the fundamental frequency of the alternating voltage.
[0082] In the present embodiment, the control unit 52 has a control port 60, which serves to receive data specifying the frequency range. The control port 60 is communicatively coupled to a communication unit 54. The communication unit 54 serves to establish a wireless communication connection via short-range radio with an end device, such as a smartphone, tablet, or the like. This allows a user to specify the frequency range via the end device.
[0083] The input unit 52 is part of an evaluation unit 46, which evaluates the sensor signal from the current sensor unit 30. For this purpose, the evaluation unit 46 is connected to the sensor port 56. The evaluation unit 46 has a computer unit 48 for evaluation, which is connected to a storage unit 50.
[0084] 14
[0085] is coupled. In the memory unit 50, in addition to parameters for evaluation, a computer program product is also stored, which serves to operate the computer unit 48 in a suitable manner so that the evaluation, as will be explained below, can be carried out.
[0086] The method described below with reference to FIG. 3 serves to accurately determine interference frequencies, especially non-harmonic interference frequencies, with minimal effort. In the present embodiment, it is assumed that the fundamental frequency fNetz is approximately 50 Hz. Furthermore, a frequency range of 700 Hz to 750 Hz is specified for analysis using the input unit. As can be seen from FIG. 3, the frequency range to be examined is defined in a first step. The frequency range to be examined can be determined, for example, based on a spectral analysis in which a larger spectrum has been examined with lower resolution, with the frequency range being selected by the user. The user can, among other things, consider non-harmonic components that are particularly prominent, i.e., whose amplitude in the spectrum is particularly large compared to neighboring frequency components.
[0087] The frequency range can, of course, also be specified due to interference from one of the consumers 28, whereby the interference may be caused by an as yet unknown interference frequency. The specified frequency range can be stored in the memory unit 50 for further evaluation. In the present embodiment, the frequency range of 700 Hz to 750 Hz is chosen as an example, that is, 14 times and 15 times the fundamental frequency.
[0088] Within this frequency range, a spectral analysis is now performed. For this purpose, the frequency to be examined is first set to a k-multiple of the fundamental frequency fNetz. This frequency is subsequently denoted by f p marked. The following applies:
[0089] fp fNetz
[0090] In this configuration, k = 15, from which f p = 750 Hz.
[0091] In a subsequent step 66, sampling is carried out over several periods l of the fundamental frequency fNetz, whereby in the present embodiment five periods are assumed. In alternative embodiments, it may be provided that the number 202422688 foreign version
[0092] The number of periods is at least three. Taking the sampling theorem into account, it follows that in the present configuration the data rate f s The data rate should be at least 1500 values per second. Suitable equipment is already available for a sampling rate of 4000 values per second, so the current design provides for a data rate of f s A sampling rate of 4000 / s is selected. This results in the following number of samples:
[0093] l
[0094] N = — f s
[0095] JNetz
[0096] Using these values, the number n of samples is therefore 400.
[0097] A first part N1 of the number N of samples is used for applying a Fast Fourier Transform, where the first part N1 is smaller than the number N. Here, the samples are weighted using a von Han window function, as shown below:
[0098]
[0099] Thus, in step 68, the transformation follows according to the following formula:
[0100]
[0101] In a further step 70, a second part N2 of the number N of samples is selected, where in the present embodiment the number of the first part N1 is equal to the number of the second part N2. The first part N1 differs from the second part N2 in that the first sample of the second part N2 is a later sample m. Assuming that the calculation of Y1 starts with index n = 0, m > 0 with a preferred value of m = 1, so that Y2 can be determined according to the following formula:
[0102] 2nf p n
[0103] Y2 = w(n)x n e J fs
[0104] n=l202422688 Foreign version
[0105] 16
[0106] In the present embodiment, N1 = N2, where N2 is shifted by one sample value. However, it is also possible in principle to provide a shift of more than one sample value.
[0107] In a subsequent step 72, the desired interference frequency f is determined as follows:
[0108] f _ f larg (72) - arg (71) |
[0109] 7 27T
[0110] The interference frequency f determined in this way can be visually displayed to the user in step 74 using a display unit (not shown). Furthermore, it is of course possible that in step 74 this value is transmitted to the user's terminal device via the communication unit 54, so that a display or signal can be generated there.
[0111] Step 64 introduces a time delay, after which the process is repeated starting with step 66. Alternatively or additionally, it can also be provided that a user input triggers a repetition of the process in step 74.
[0112] The exemplary embodiments serve solely to illustrate the invention and are not intended to limit it. 202422688 Foreign version
[0113] 17
[0114] Reference symbol list
[0115] 10 Low-voltage switchgear
[0116] 12 Energy supply network
[0117] 14 departures
[0118] 16 departures
[0119] 18 departures
[0120] 20 departures
[0121] 22 departures
[0122] 24 departures
[0123] 26 circuit breakers
[0124] 28 consumers
[0125] 30 Current sensor unit
[0126] 32 Connection cable
[0127] 34 Diagnostic device
[0128] 36 Diagnostic device
[0129] 38 Diagnostic device
[0130] 40 diagnostic device
[0131] 42 Diagnostic device
[0132] 44 Diagnostic device
[0133] 46 evaluation units
[0134] 48 computer units
[0135] 50 storage units
[0136] 52 reference unit
[0137] 54 Communication unit
[0138] 56 Sensor connection
[0139] 58 subnetwork
[0140] 60 standard connection
[0141] Step 62
[0142] 64 steps
[0143] Step 66
[0144] 68 steps
[0145] 70 steps
[0146] 72 steps
[0147] 74 steps
Claims
202422688 Foreign version 18 Patent claims 1. Application of a method for determining at least one disturbance frequency (f) of at least one alternating voltage or alternating current of an electrical power supply network (12) in a switchgear assembly (10) which has a plurality of outgoing circuits (14, 16, 18, 20, 22, 24) for consumers and / or electrical power generators, wherein the alternating voltage or alternating current has a fundamental frequency (f ne tz) wherein the alternating voltage or alternating current is detected by means of a sensor unit (30) and the sensor unit (30) provides a sensor signal, wherein the sensor signal is evaluated by means of an evaluation unit (46) in order to determine the at least one disturbance frequency (f), where - for evaluation by the evaluation unit (46) a frequency range is specified in which at least one disturbance frequency (f) is expected, wherein a lower frequency limit of the frequency range is greater than the fundamental frequency (f ne tz) is, - the sensor signal over a predetermined number of periods of the fundamental frequency (f ne tz) with a predefined data rate (f s ) is sampled in a time-discrete manner to obtain a predetermined number (N) of samples, - a Fourier transform is applied to a given first part (N1) of the number (N) of samples to determine a first phase (Y1), - the Fourier transform is applied to a given second part (N2) of the number (N) of samples to determine a second phase (Y2), where the second part (N2) is different from the first part (N1), and - that at least one disturbance frequency (f) is determined at least as a function of the first and second phases (Y1, Y2), wherein the method automatically checks the outputs (14, 16, 18, 20, 22, 24) with regard to the origin of the at least one interference frequency, narrows down the origin of the at least one interference frequency and identifies an interference source that causes the at least one interference frequency.
2. Application according to claim 1, characterized in that the method is repeated automatically, wherein a modified frequency range is specified.
3. Application according to claim 2, wherein the method is repeated at predetermined times or depending on certain events. 202422688 Foreign version 19 4. Application according to one of the preceding claims, wherein the frequency range is transmitted from a remote location to the evaluation unit (46) via a communication link and a communication interface of the evaluation unit (46).
5. Switchgear (10) comprising a plurality of outputs (14, 16, 18, 20, 22, 24) for consumers and / or electrical power generators, with a diagnostic device (34, 36, 38, 40, 42, 44) for determining at least one disturbance frequency (f) of at least one alternating voltage or alternating current of an electrical power supply network (12), wherein the alternating voltage or alternating current has a fundamental frequency (f ne tz) exhibits, wherein the diagnostic device (34) exhibits: - a sensor connection (56) for connecting a sensor unit (30) for detecting the alternating voltage or alternating current and for providing a sensor signal, - an evaluation unit (46) connected to the sensor connection (56) for evaluating the sensor signal in order to determine at least one disturbance frequency (f), wherein the evaluation unit (46) has a preset port (60) for receiving data specifying a frequency range in which at least one disturbance frequency (f) is expected, wherein a lower frequency limit of the frequency range is greater than the fundamental frequency (fnetz), wherein the evaluation unit (46) is designed, - the sensor signal over a predetermined number of periods of the fundamental frequency (f ne tz) with a predefined data rate (f s ) to sample in a time-discrete manner in order to obtain a predetermined number (N) of samples, - to apply a Fourier transform to a given first part (N1) of the number (N) of samples in order to determine a first phase (Y1), - to apply the Fourier transform to a given second part (N2) of the number (N) of samples in order to determine a second phase (Y2), where the second part (N2) is different from the first part (N1), and - to determine at least one disturbance frequency (f) depending on the first and second phases (Y1, Y2), wherein the method automatically checks the outputs (14, 16, 18, 20, 22, 24) with regard to the origin of the at least one interference frequency, narrows down the origin of the at least one interference frequency, and identifies an interference source causing the at least one interference frequency. 202422688 Foreign version 20 6. Switchgear (10) according to claim 5, characterized by that the evaluation unit (46) has a specification unit (52) which is configured to specify the frequency range based on a captured spectrum.
7. Switchgear (10) according to one of claims 5 or 6, wherein the evaluation unit (46) has a communication interface which is in communication connection with an external communication device, via which the at least one interference frequency can be transmitted.
8. Switchgear (10) according to claim 7, wherein the communication device is a user terminal device.
9. Switchgear (10) according to one of claims 5 to 8, wherein the diagnostic device (34, 36, 38, 40, 42, 44) is integrated into a power monitoring device used in switchgear.