Method for controlling drive systems, and drive systems

Abstract

The invention relates to a method for controlling an electric machine (202) fed by an electronic controller (201), wherein at least one setting of the controller (201) is automatically modified such (103) that at least one parameter can be reduced that characterizes machine noise (207) and can be measured by an acoustic measuring device (203).

Description

[0001] Description

[0002] Methods for controlling drive systems and drive systems

[0003] The present disclosure relates to a method for controlling an electrical, preferably rotary, machine fed by an electronic control device.

[0004] Compared to motors running directly on the mains, converter-fed motors generate additional noise that depends on various parameters. While this noise cannot be completely eliminated, it can be minimized. However, optimal adjustment by the user is difficult, as it depends on many factors (including system-related ones).

[0005] The present disclosure relates to methods and systems that enable a reduction of noise generated by a drive system.

[0006] In principle, methods for reducing motor noise are known. One possible approach is to increase the pulse frequency of the converter, as this reduces the current ripple and usually also increases mechanical damping. The main disadvantage of this method is the required power derating of the converter, which may require a larger size and consequently take up more space.

[0007] The object of the present invention is therefore to provide methods and systems that are simple and do not require any change to the drive system.

[0008] The object is achieved by a method mentioned at the outset in that at least one setting of the control device is automatically changed in such a way that at least one parameter characterizing machine noises that can be measured by means of an acoustic measuring device is optimized.

[0009] As a rule, the measurement of the parameter characterising the machine noise is carried out on the machine.

[0010] The term "on the machine" means that the measurement is carried out using a sensor device that is separate from the machine, preferably portable and in particular not attached to the machine.

[0011] It can be provided that the parameter is measured once before and once after the change of at least one setting and the setting is adopted depending on an optimization of the at least one parameter.

[0012] The parameter can be loudness, sharpness, tonality, or roughness, etc.

[0013] It can be provided that the at least one setting concerns magnetic flux, switching frequency, intermediate circuit voltage, modulation, in particular frequency modulation, pulse pattern, or a combination thereof. In the case of frequency modulation, a special case that can be considered is, for example, wobbling, i.e., an automatic, permanent change in the switching frequency.

[0014] In one embodiment, the optimization of the at least one parameter may include an optimization loop, which is run through until a predeterminable termination criterion is met. In particular, the optimization loop is run through several times until the termination criterion is met.

[0015] It can be useful if the termination criterion is based on a determination of an improvement in the noise and / or includes an optimization target for the at least one parameter. In addition, the task is carried out using a mobile or portable computing unit for controlling an electrical, preferably rotary, machine fed by an electronic control device, the computing unit being connectable to an acoustic measuring device, the measuring device being provided for determining at least one parameter characterizing machine noise, in order to obtain the at least one parameter, the computing unit being connectable to the electronic control device and being designed to change at least one setting of the control device in such a way that the parameter is optimized.

[0016] When determining the parameter, the noise is recorded by the measuring device, which then generates a corresponding measurement signal from which the parameter is determined. The measurement signal can be evaluated either by the measuring device or by the computing unit, or even externally, i.e., by a computing system such as the cloud.

[0017] It can be provided that the computing unit is structurally separate from the acoustic measuring device and can be connected to the acoustic measuring device by cable, for example via USB, or wirelessly, for example via Bluetooth.

[0018] For example, the computing unit may include the acoustic measuring device.

[0019] It can be provided that the acoustic measuring device has one or more acoustic sensors, for example microphones.

[0020] Preferably, the computing unit can be connected to the electronic control device via a web server provided in the electronic control device (or via the local user interface of the electronic control device). Alternatively, the electronic control device can be controlled via a data bus.

[0021] For example, the computing unit can be connected to the electronic control device via a dedicated adapter. The adapter, e.g., a Bluetooth-enabled adapter, can be structurally separate from the computing unit and / or the electronic control unit. Alternatively, the adapter can be included in the computing unit or the control device. In particular, the computing unit can be configured as a smartphone and connectable to the control device via a Profinet adapter.

[0022] It can be provided that one or more further devices and / or apparatuses are interposed between the computing unit and the electronic control device. For example, the computing unit can be connected (for example via the adapter described above) to an edge device, which can be designed as an industrial computer, or to a programmable logic controller (PLC), which is connected to the electronic control device and can change the setting parameters of the electronic control device when, for example, corresponding commands are transmitted from the computing unit to the edge device or to the PLC.

[0023] In addition, the object is achieved with a drive system which has the above-described computing unit, an electronic control device, an electrical machine and an acoustic measuring device, wherein the electrical machine can be connected to a power supply network by means of the electronic control device, wherein the computing unit is connected to the electronic control device and to the acoustic measuring device.

[0024] It can be provided that the electronic control device is designed as a converter. It can be provided that the electrical machine is a motor, in particular a synchronous or asynchronous motor.

[0025] The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the figures. They show:

[0026] FIG 1 is a flowchart of a control method, and

[0027] FIG 2 a drive system .

[0028] In the exemplary embodiments and figures, identical or similarly functioning elements may be provided with the same reference numerals. The illustrated elements and their relative sizes are generally not to scale; rather, individual elements may be shown larger in size for clarity and / or clarity.

[0029] FIG 1 shows a flow chart of a method for controlling an electrical machine, for example a rotary machine, which is fed by an electronic control device.

[0030] The electronic control device can be designed as a converter. Converters can be used that have an intermediate circuit and first convert an input voltage into a direct current in the intermediate circuit before converting this voltage back into an alternating current to power the electrical machine.

[0031] The disclosed method is feasible for all combinations of converters and machines.

[0032] The electrical machine is preferably an electrical rotary machine, in particular a motor, e.g., an asynchronous or synchronous machine. The method can be implemented in machine-readable code that can be executed by a computing unit.

[0033] In the context of the present disclosure, the term "computing unit" refers to an electronic computing device, for example a computer, a virtual machine, a virtual container, a host, a server, a client device, a laptop, a tablet, and / or a mobile device (e.g., a smartphone), or to a plurality of electronic computing devices that cooperate to perform the described method or functions.

[0034] The computing unit may include various hardware components, such as, but not limited to, one or more processors, data buses, volatile and / or non-volatile memory, input devices, power sources, network interfaces, user interfaces, and / or other computer components. The processors may include one or more microprocessors capable of executing instructions from memory. Additionally or alternatively, the processors may include application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and / or other devices designed to perform some or all of the methods or functions disclosed herein without necessarily retrieving instructions from memory.

[0035] The machine-readable code may, for example, be in the form of an application or, derived from English, an app. In the context of the present disclosure, the term "application (or app)" refers to one or more computational modules, programs, and / or a set of computational instructions executed by a computer system containing one or more computing units. For example, an app may include or be embodied as one or more software modules, software objects, one or more software instances, and / or other types of executable code.

[0036] It can also be provided that the computing unit is connected to additional resources, for example via another local or global network, in order to access additional information relating to the electronic control device and / or electrical machine and / or its operation and thereby improve optimization. For example, it can be provided that the app accesses information on an (internal or external) server in order to optimize more specifically. Such information can include characteristic properties of the machine, for example mechanical resonance frequencies of the motor or similar.

[0037] After starting 100 the app on the computing unit , a connection can be established with the drive, for example with the inverter 101 .

[0038] After the connection is established, an acoustic measurement can be initiated via the app, in which noises emitted by the drive, for example, the converter or the electric machine, are measured 102 using sensors external to the drive or included in the computing unit. In other words, a reference measurement is performed.

[0039] Subsequently, at least one drive parameter is changed automatically, i.e., without the need for user input 103, with the aim of reducing machine noise.

[0040] To determine which drive parameter(s) are changed, for example, the evaluation of the acoustic reference measurement and / or expert knowledge can be used. Alternatively, the parameter to be changed can be randomly selected. After at least one drive parameter has been changed, another acoustic measurement can be performed 104 to investigate the influence of the parameter change on the machine noise.

[0041] The results of the further acoustic measurements are evaluated 105 . The influence is quantified by one or more parameters characterizing the machine noise. The parameter(s) can be loudness, sharpness, tonality, or roughness, etc. The influence can also be quantified in terms of a combination, in particular a weighted combination of the (individual) parameters.

[0042] In other words, the parameter(s) or their combination defines an optimization criterion with respect to which the noise is to be optimized.

[0043] If an improvement is determined with respect to the optimization criterion 106, the optimization can continue by changing the same and / or other parameters of the electronic control device, then performing another measurement, comparing its results with the results of the last one, and so on. In other words, the optimization includes an optimization loop 107.

[0044] The optimization loop 107 can be configured to run until a predefined termination criterion is reached. For example, the termination criterion can stipulate that if no improvement occurs after several runs in which various drive parameters are changed, the optimization is terminated.

[0045] Multiple runs are therefore preferable, especially since several parameters of the electronic control system, especially the converter, can be influenced during optimization. With multiple runs, several parameter changes and, consequently, several optimization directions can be tested.

[0046] In a preferred embodiment, the termination criterion can be the achievement of predetermined values ​​of the parameters characterizing the machine noise. In other words, the optimization can be terminated when a predetermined optimization goal is achieved.

[0047] The selection of the termination criterion and in particular the optimization goal can be done automatically and does not require any interaction with the user.

[0048] Nevertheless, during optimization, two or more optima can be found that differ with respect to individual parameters, e.g., a loud but pleasant noise versus a less loud but unpleasant one, e.g., a shrill noise. In such a case, the variants could be presented to the user and displayed on a display for selection.

[0049] Preferably, the changed drive setting is adopted when an improvement in the noise is detected.

[0050] The advantage is that the app user does not have to search for and adopt the optimal drive parameters himself, as this can be done fully automatically.

[0051] By changing the drive parameters, for example, magnetic flux, switching frequency, intermediate circuit voltage, modulation method, e.g. RZM / Flattop, optimized pulse patterns, etc., or a combination of these can be influenced to reduce machine noise.

[0052] The change in the intermediate circuit voltage can lead to different control levels on the motor side and thus different current harmonics, which can reduce the motor noise.

[0053] In addition to a reduction in the flux, an increase in the magnetic flux and the associated increase in the control factor can also lead to a reduction in noise, depending on the operating point of the electrical machine and / or converter. Increasing the flux is particularly possible if the electrical rotating machine has sufficient design reserves, so that the iron does not saturate, or only saturates to a limited extent, when the magnetic flux increases. Furthermore, the pulse frequency can be increased to reduce noise if an increase in the flux reduces the motor current.

[0054] In other words , FIG 1 shows a workflow for optimising the machine with regard to the noise level generated .

[0055] FIG 2 shows a drive system which may correspond to the drive system according to the invention.

[0056] The drive system comprises a mobile computing device 200, an electronic control device 201, for example a converter, an electrical rotary machine 202, for example an electric motor, and an acoustic measuring device 203, for example a microphone, which in the present case forms a structural unit with the mobile computing device 200.

[0057] The electric rotary machine 202 is connected to a power supply network 204 by means of the converter.

[0058] The mobile computing device 200 is connected to the electronic control device 201 via a network 205. The network 205 can be configured as a local or global network. For example, the control device 201 can have a web server 206, via which the mobile computing device 200 can be connected to the control device 201.

[0059] As mentioned herein, the computing unit can alternatively or additionally be connected to the electronic control device via a dedicated adapter (not shown here). The adapter, e.g., a Bluetooth-enabled adapter, can be structurally separate from the computing unit and / or the electronic control unit. Alternatively, the adapter can be included in the computing unit or the control device.

[0060] Furthermore, it can be provided that one or more further devices and / or apparatuses are interposed between the computing unit and the electronic control device (not shown here). For example, the computing unit can be connected (for example via the adapter described above) to an edge device, which can be designed as an industrial computer, or to a PLC, which is connected to the electronic control device and can change the setting parameters of the electronic control device, for example when corresponding commands are transmitted from the computing unit to the edge device or to the PLC.

[0061] During operation, the drive system and in particular the control device 201 and / or the electric rotary machine 202 emits sound waves 207 which are perceived as noise.

[0062] After connecting the mobile computing device 200 to the drive system, the sound waves 207 can be measured with the acoustic sensors 203 provided for this purpose in the computing device 200.

[0063] The results of this measurement serve as starting points for subsequent optimization. The app can include a recommendation engine that can suggest a selection of different optimization goals to the user, for example, regarding loudness and / or sharpness.

[0064] After the measurement, an optimization process is started, e.g., the optimization described with reference to FIG. 1. The app changes the settings (of the electronic control device 201) and assesses (e.g., based on parameter values ​​such as loudness, sharpness, etc.) whether this change has reduced the engine noise as expected and / or whether the optimization goal has already been achieved. A figure of merit can be calculated from the optimization parameters for assessment purposes.

[0065] The selection of the drive parameters to be changed can be made based on one or more of the following criteria: trial and error changes within certain limits, fixed rules for optimization steps, recourse to "experience / AI", e.g. from the cloud.

[0066] Parameter changes can be optimized by reference to additional information about the electronic control unit 201 and / or the electric machine 202. For example, if mechanical resonances of a motor are known, a targeted avoidance of excitations in this frequency range can be attempted—as a fixed rule.

[0067] This has the advantage that the user does not need to be familiar with the relevant parameters of the converter.

[0068] In addition, the optimization process described here is much faster since no manual parameter change of the control device 201 is necessary.

[0069] In addition, f granular settings are possible, e.g.

[0070] Switching frequency in 100 Hz steps (if enabled by control device) which is otherwise not available to a user.

[0071] The purpose of this description is merely to provide illustrative examples and to indicate further advantages and special features of this invention. In particular, the features disclosed in connection with the methods described herein can be usefully used to further develop the systems described herein, and vice versa.

Claims

Patent claims 1. Method for controlling an electrical machine (202) fed by an electronic control device (201), wherein at least one setting of the control device (201) is automatically changed (103) in such a way that at least one parameter characterizing machine noises (207) that can be measured by means of an acoustic measuring device (203) is optimized.

2. The method according to claim 1, wherein the parameter is measured once before (102) and once after (104) the change of the at least one setting and the setting is adopted (106) as a function of an optimization of the at least one parameter.

3. The method according to claim 1 or 2, wherein the parameter is loudness, sharpness, tonality or roughness.

4. The method according to any one of claims 1 to 3, wherein the at least one setting relates to magnetic flux, switching frequency, intermediate circuit voltage, modulation method, pulse pattern or a combination thereof.

5. The method according to one of claims 1 to 4, wherein the optimization of the at least one parameter comprises an optimization loop (107) which is run through until a predefinable termination criterion is reached.

6. The method according to claim 5, wherein the termination criterion is based on a determination of an improvement in the noise and / or comprises an optimization target for the at least one parameter.

7. A computing unit for controlling an electrical machine (202) powered by an electronic control device (201), wherein the computing unit (200) with an acoustic measuring device (203), wherein the acoustic measuring device (203) is provided for determining at least one parameter characterizing machine noises (207), is connectable in order to obtain the at least one parameter, the computing unit (200) is connectable to the electronic control device (201) and is designed to change at least one setting of the control device (201) such that the parameter is optimized.

8. A computing unit according to claim 7, wherein the computing unit (200) is structurally separate from the acoustic measuring device and can be connected to the acoustic measuring device by cable or wirelessly, for example via Bluetooth.

9. A computing unit according to claim 7, wherein the computing unit comprises the acoustic measuring device (203).

10. Computing unit according to one of claims 7 to 9, wherein the acoustic measuring device (203) comprises one or more acoustic sensors, for example microphones.

11. A computing unit according to one of claims 7 to 10, wherein the computing unit (200) is connected to the electronic control device (201) via a (201) provided web server (206) or via a corresponding adapter.

12. Drive system comprising - a computing unit (200) according to one of claims 7 to 11, - an electronic control device (201), - an electrical machine (202) , - an acoustic measuring device (203), wherein the electric machine (202) is connected to a power supply network by means of the electronic control device (201) (204) is connectable, wherein the computing unit (200) is connected to the electronic control device (201) and to the acoustic measuring device (203).

13. Drive system according to claim 12, wherein the electronic Control device is designed as a converter.

14. Drive system according to claim 12 or 13, wherein the electric machine is a motor, in particular a synchronous or asynchronous motor.

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