Method for information exchange between an external recipient and a pump

Abstract

The invention relates to a method for information exchange between an external recipient and a pump comprising an electric motor as pump drive and a frequency converter for controlling, in a rotational speed-regulated manner, the motor, wherein the pump generates an acoustic information signal that can be detected by the external recipient, characterised in that during regular pump operation, at least one operating parameter of the frequency converter is varied such that the pump, during regular pump operation, emits an acoustic information signal (20) that can be detected by the external recipient.

Description

[0001] Description

[0002] Method for exchanging information between an external receiver and a pump

[0003] The invention relates to a method for exchanging information between an external receiver and a pump comprising an electric motor as pump drive and a frequency converter for speed-controlled control of the motor, wherein the pump generates an acoustic information signal which is detectable by the external receiver.

[0004] Modern pumps, such as heating circulation pumps, are now operated with variable speed control for efficiency reasons. The pump drive, in the form of an electric motor, is powered by a frequency converter. The output voltage generated by the frequency converter, which is fed to the motor as motor voltage, can be adjusted to adjust the speed.

[0005] In addition to energy-efficient pump control, it is also becoming increasingly important to establish a communication link between the pump and at least one external receiver for the purpose of information exchange. The external receiver can be a central control or management unit or simply a commercially available smartphone or tablet running an application for communicating with the pump. Pump operating data is to be transmitted via the interface for external monitoring, management, or control. To enable the pumps to communicate, separate communication hardware must be integrated into the pump. One known example is the integration of a Bluetooth communication module, although this is associated with increased production costs for the pump.

[0006] The object of the present invention is to provide a simple and cost-effective communication option for a pump.

[0007] This object is achieved by a method for exchanging information between an external receiver and a pump according to the features of claim 1. Advantageous embodiments of the method are the subject of the dependent claims. Furthermore, the object is achieved by a pump according to the features of claim 12.

[0008] Based on a known pump that has an electric motor and a frequency converter for controlling the pump's speed, it is proposed to dispense with separate hardware for communication with at least one external receiver. Instead, the existing hardware of the frequency converter is to be repurposed for communication purposes, which is made possible by adapting the frequency converter's control system. In particular, a software-based control logic of the frequency converter can be easily adapted.

[0009] According to the invention, it is specifically proposed to vary at least one operating parameter of the frequency converter during ongoing pump operation in such a way that the pump generates a dedicated acoustic signal during ongoing pump operation that can be clearly detected by an external receiver. In simple terms, by specifically modifying the motor control, which, however, does not significantly affect the speed control, the regular operating noise of the pump is specifically changed so that this can be detected by an external receiver.

[0010] This provides a simple way to exchange information between the pump and any receiver. For most applications, this capability is sufficient, for example, to signal an alarm or other pump status. An existing pump requires no hardware upgrade; instead, a programmatic adjustment of the frequency converter is sufficient. This allows existing pumps to be subsequently modified and retrofitted with a communication capability.

[0011] When implementing the procedure, it is important to ensure that the regular pump function is ideally not affected or at least only slightly affected by the variation of the operating parameters of the frequency converter.

[0012] According to an advantageous embodiment, for example, the output voltage generated by the frequency converter, i.e. the motor supply voltage, can be varied, thereby generating a detectable acoustic signal. For regular operation of the pump motor, the motor voltage is generated at the output of the frequency converter with a variable fundamental frequency and amplitude. Preferably, this voltage can, for example, be impressed with a voltage curve with a higher frequency than the fundamental frequency, i.e. a so-called high-voltage injection can be carried out by suitable control of the frequency converter. By suitably impressing a high-frequency voltage curve onto the fundamental frequency motor voltage, a definable acoustic signal can be generated during ongoing pump operation, which can be detected by the receiver. This additional frequency modulation of the motor voltage has no or only marginal influence on regular pump operation, so that the pump continues to function properly.By generating the acoustic signal via high-frequency injection, the pump can thus emit an acoustic indication as needed, which can be detected by any device equipped with an acoustic receiver.

[0013] Instead of the possibility of high-frequency injection, an advantageous embodiment of the invention proposes modifying the switching frequency at which the integral switching elements of the inverter module of the frequency converter are switched. Adjusting the switching frequency generally has no influence on the generated output voltage, but does lead to a different acoustic operating noise from the pump, which in turn can be detected as an information signal by a receiver. For example, it is conceivable that the switching elements are originally switched at a usually constant reference switching frequency. If information is to be transmitted from the pump to a receiver, the switching frequency is preferably increased or reduced by a defined amount. This deviation of the current switching frequency from an original reference switching frequency can be detected acoustically and thus recognized by a receiver.For example, with an original reference switching frequency of 16 kHz, information such as an alarm could be signaled from the pump to a receiver by reducing the switching frequency to 15 kHz.

[0014] According to a preferred extension of the invention, the defined change in the switching frequency can also be used to transmit a binary data sequence from the pump to a receiver. For this purpose, the change in the switching frequency must be time-synchronized, i.e., the change in the switching frequency must occur at defined times. If the receiver is synchronized with the temporal rate of change, a binary data sequence can be transmitted from the pump to the receiver.

[0015] The method according to the invention for transmitting information can be used for various applications in which information is to be transmitted from the pump to at least one receiver. For example, it is conceivable for the pump to transmit its current status using the method. Pump operation without modified operating parameters of the frequency converter, for example, signals a proper functioning of the pump, while operation with modified operating parameters and the subsequent generation of an acoustic signal is intended to indicate an anomaly in the pump's behavior.

[0016] In practice, the pump manufacturer often has an interest in ensuring that the pumps used by the customer are registered, i.e. the pump manufacturer can clearly link the pump to a specific customer identifier in order to be able to offer dedicated customer service. In this case, it is advantageous, for example, if modifying the operating parameter generates an acoustic signal, which indicates to a receiving device whether or not the pump has already been registered with the manufacturer. A dedicated application running on a smartphone, tablet, or laptop could thus detect the acoustic signal in the reception area and automatically assist the user in registering the pump. The application could also indicate to the customer whether the pump is functioning properly or whether there is a fault.

[0017] To capture and evaluate the acoustic signal, the external receiving device preferably uses a built-in, commercially available microphone. Using audio analysis of the recorded audio signal, particularly frequency analysis such as Fast Fourier Transformation (FFT) or Discrete Fourier Transformation (DFT), an application running on the device can extract the transmitted information from the recorded audio signal.

[0018] The acoustic signal generated by the process can be audible to humans, so that, in principle, no technical device is required for information transmission. Instead, the user can already detect and ideally evaluate the changed operating noise of the pump. However, there is nothing to prevent the modification of the operating parameter from being selected in such a way that the human cannot perceive the change in operating noise, i.e., the generated acoustic signal.

[0019] In addition to the method according to the invention, the invention also relates to a pump, in particular a centrifugal pump, comprising an electric motor and a frequency converter for variable speed control of the electric motor. According to the invention, the frequency converter, in particular the control of the frequency converter, is configured to carry out the steps of the method according to the invention. Consequently, the pump according to the invention has the same advantages and properties as were already discussed above with reference to the method. For the sake of simplicity, a repeated explanation is omitted. The pump can be a heating circulating pump, a circulation pump for a pressure boosting system or another centrifugal pump. The electric motor is a converter-controlled AC or three-phase motor. In general, the method can be used for any type of motor that is controlled by means of a frequency converter, such as, for example:Synchronous and asynchronous motors, reluctance motors, synchronous reluctance motors, etc.

[0020] Further advantages and features of the invention will be explained in more detail below with reference to the application steps shown in the figures. They show:

[0021] Fig. 1 : a schematic sketch of the process steps according to a first application scenario and

[0022] Fig. 2: a sketch of the schematic steps during a second application scenario.

[0023] A possible application scenario for the method according to the invention is described below. The pump 1 shown here is a heating circulation pump installed in the heating system of the customer 5. The heating circulation pump 1 comprises an electric motor that is controlled energy-efficiently by means of an integrated frequency converter. The method according to the invention is used here to have the hardware of the pump 1 output status information, which can then be detected by any terminal device 2. In the specific exemplary embodiment, this status information, hereinafter referred to as the "acoustic red or green light," indicates whether the pump 1 has been registered with the pump manufacturer 3 or not. The sketch in Figure 1 shows the schematic steps for the registration process.

[0024] Step 1 :

[0025] In the delivery state of pump 1, it emits an acoustic signal 20 ("acoustic red light"), which can be detected via the microphone of a smartphone 2 and which contains a device ID of pump 1. The acoustic signal 20 is generated using the method according to the invention by varying an operating parameter of the installed frequency converter of pump 1.

[0026] In addition to the voltage waveform at a fundamental frequency required to operate the motor, it is possible to generate an additional high-frequency voltage waveform through the frequency converter using what is known as high-frequency injection. This high-frequency voltage waveform can be injected in such a way that an acoustic signal 20 is generated, which can be recorded and evaluated by the smartphone 2 and the application installed there. In particular, the application performs a real-time FFT analysis of the signal previously recorded via the smartphone's microphone.

[0027] Alternatively, an acoustically detectable or perceptible signal 20 could be generated by varying the switching frequency of the frequency converter, so that the deviation from a fixed reference frequency can be used to transmit information. With a reference switching frequency of 16 kHz, for example, a switching frequency of 15 kHz could signal that pump 1 is not registered ("acoustic red light"). The fundamental frequency for the actual operation of the motor is usually in the range 50 Hz to 300 Hz and is not affected by the variation in the switching frequency. If a fixed time window is specified for the variation between two or more switching frequencies, it is possible to send rudimentary digital information such as the DeviceID in the form of binary "1" and "0" as a "broadcast".

[0028] When a corresponding application is run on smartphone 2, the acoustic signal 20 can be evaluated and pump 1 identified as a not yet registered pump. Furthermore, the acoustic signal 20 can already contain the device ID of pump 1, which smartphone 2 receives and can use in the further process. Step 2:

[0029] After smartphone 2 receives the device ID of pump 1, user 5 is redirected to an online registration of pump 1 via the smartphone 2 app. The connection between smartphone 2 and cloud 3 can be established, at least in part, via a mobile communications standard, e.g., LTE, or Wi-Fi. The device ID is transferred to a cloud service 3 of the pump manufacturer, where it is linked to a customer ID.

[0030] Step 3

[0031] After the Customer ID has been provided and linked to the Device ID, the Customer ID is subsequently transferred to Pump 1 via an optional additional digital communication connection between Smartphone 2 and Pump 1 in accordance with the Bluetooth / Bluetooth Low Energy standard. The generated acoustic signal 20 of Pump 1 changes to an "acoustic green light," e.g., by reversing the variation of the operating parameter. However, the transfer of the Customer ID to Pump 1 is only optional; alternatively, Pump 1 could also be notified that registration was successful by a manual input on the pump's control panel.

[0032] Step 4:

[0033] The registered pump 1 sends an identifier of its health value 4 to the app of the smartphone 2, either via the acoustic signal 20 or preferably via the established Bluetooth connection.

[0034] Step 5:

[0035] This health value 4 is sent from smartphone 2 to cloud 3. In cloud 3, a comparison is made between the reported health value 4 of pump 1 and the health values ​​7 of an anonymous fleet 10 of comparable pump models. Customer 5 then receives an evaluation 6 of their own pump 1 compared to the anonymous fleet 10. Step 6:

[0036] In the event of a malfunction or the occurrence of an anomaly, the acoustic signal 20 is used again to alert customer 5 to the anomaly in pump 1. The acoustic "green light flashes," thus signaling an anomaly. Service 11 can now actively approach customer 5 with the known customer ID and offer service for pump 1.

[0037] Fig. 2 shows a modified application scenario for the method according to the invention. In contrast to the first scenario according to Fig. 1, in the use case according to Fig. 2, a fault already occurs in a pump that has not yet been registered ("red light"). Pump 1 is able to automatically detect the anomaly even without a connection to the cloud 3. After the anomaly is detected by pump 1, the acoustic signal is used to alert the customer to pump 1. If the acoustic signal is recognized by smartphone 2, the registration process should also be executed here in order to link the unique DeviceID of pump 1 with a CustomerID and thus be able to offer customer-specific service.

Claims

Patent claims Method for exchanging information between an external receiver and a pump. Method for exchanging information between an external receiver (2) and a pump (1), comprising an electric motor as the pump drive and a frequency converter for speed-controlled control of the motor, wherein the pump (1) generates an acoustic information signal (20) that can be detected by the external receiver (2), characterized in that at least one operating parameter of the frequency converter is varied during regular pump operation such that the pump (1) emits an acoustic information signal (20) that can be detected by the external receiver (2). Method according to claim 1, characterized in that the at least one operating parameter is the motor voltage generated at the output of the frequency converter.Method according to claim 2, characterized in that a higher-frequency voltage is modulated onto the generated motor voltage by means of the frequency converter, which generates an acoustic signal (20) detectable by the receiver (2) during pump operation. Method according to claim 1, characterized in that the switching frequency of the integrated inverter of the frequency converter is varied as an operating parameter. whereby an acoustic information signal (20) is generated that is detectable during regular pump operation. Method according to claim 4, characterized in that the information content of the acoustic signal (20) is determined by the deviation of the varied switching frequency of the frequency converter from an original switching frequency. Method according to one of claims 4 or 5, characterized in that specific information, e.g. an indicator or a binary value, can be output by a defined deviation of the switching frequency from the original reference switching frequency. Method according to one of claims 4 to 6, characterized in that the variation of the switching frequency is time-synchronized in order to enable the transmission of a binary data sequence. Method according to one of the preceding claims, characterized in that the information contained in the acoustic information signal (20) contains the state of the pump (1), e.g.Information indicating whether the pump (1) is functioning properly. Method according to one of the preceding claims, characterized in that the information contained in the acoustic information signal (20) indicates whether the pump (1) has been registered. Method according to one of the preceding claims, characterized in that the external receiving device (2) records the operating noise of the pump (1) using a microphone and extracts the transmitted information by audio signal analysis.

11. Method according to claim 10, characterized in that the audio analysis comprises a Fast Fourier Transform or a Discrete Fourier Transform.

12. Method according to one of the preceding claims, characterized in that the acoustic information signal (20) is a signal perceptible to humans.

13. Pump (1), in particular a centrifugal pump, with an electric motor and a frequency converter for variable speed control of the electric motor, characterized in that the frequency converter is configured to carry out the method according to one of the preceding claims 1 to 12.

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