ELECTRIC MOTOR DRIVEN PUMP

Abstract

An electromotorically driven pump (1) includes control electronics (6) for the connection of at least one sensor (5). The control electronics (6) are configured to detect values of an output signal (9) of the connected sensor (5) continuously or in temporal intervals, and after completion of a predefined time, to automatically set a measurement range of the sensor (5) based on the detected values.

Claims

1. An electromotorically driven pump comprising: at least one sensor providing at least one output signal; and control electronics connected to the at least one sensor and configured to detect values of the at least one output signal of the at least one connected sensor, in a continuous manner or in temporal intervals, and after completion of a predefined time, to automatically set a measurement range of the sensor on the basis of the detected values.

2. A pump according to claim 1, wherein the control electronics are configured to automatically examine and adapt the measurement range of the at least one sensor in predefined time intervals, on the basis of the values which are detected in a time interval.

3. A pump according to claim 2, wherein the control electronics are configured to carry out another setting of the measurement range, when the values detected in a preceding time interval lie at a lower limit of the set measurement range or lie at an upper limit of the set measurement range, for a summed time duration of more than 5% to 25% of the time interval.

4. A pump according to claim 1, wherein the control electronics are configured to register the connected sensor, automatically or by way of an external data input.

5. A pump according to claim 1, wherein the control electronics are configured for automatically determining a type of the sensor, or determining an identification characterisation of the sensor or determining a current measurement range of the sensor or determining any combination of a type of the sensor, an identification characterisation of the sensor and a current measurement range of the sensor.

6. A pump according to claim 1, wherein the control electronics are configured to adapt an amplification of the sensor signal in accordance with the set measurement range.

7. A pump according to claim 1, wherein the control electronics are configured to adapt an offset (11) of the sensor signal in accordance with the set measurement range.

8. A pump according to claim 1, wherein the pump is a metering pump.

9. A pump according to claim 1, wherein the pump is a centrifugal pump, in particular a wet-running centrifugal pump.

10. A pump according to claim 1, wherein the control electronics comprises a closed-loop control and that the sensor is provided for detecting a control variable.

11. A pump according to claim 1, wherein the control electronics are configured for the wireless input of sensor parameters.

12. A pump according to claim 11, wherein the control electronics comprise means for wireless data communication and can be set by way of a wirelessly connected input appliance.

13. A pump according to claim 12, wherein the input appliance is a smartphone or tablet computer, on which a software program is installed, via which a data communication with the control electronics of the pump is effected.

14. A pump according to claim 13, wherein the software program comprises a dialogue query for input of data concerning a facility, said data being necessary for the operation of the sensor.

15. A pump according to claim 1, wherein the sensor is a pressure sensor.

16. A pump according to claim 1, wherein the sensor is a temperature sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the drawings:

[0029] FIG. 1 is a circuit diagram of a hydraulic system;

[0030] FIG. 2 is a schematic circuit diagram concerning the construction of a sensor;

[0031] FIG. 3 is a view of graphs showing an adaptation of the measurement range of a pressure sensor;

[0032] FIG. 4 is a view of graphs showing how the adaptation of the measurement range affects the measurement;

[0033] FIG. 5 is a diagram showing the adaptation of amplification and offset.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] Referring to the drawings, FIG. 1 by way of example shows a hydraulic circuit, with a first pump 1 which delivers to a consumer 2, whose exit is connected to the entry of the pump 1 as well as to the entry of a second pump 3, at the exit of which second pump a valve 4 connects, said valve connecting the exit of the second pump 3 to the entry of the first pump 1.

[0035] A pressure sensor 5 is arranged parallel to the valve 4. This pressure sensor 5 is a differential pressure sensor which detects the pressure drop at the valve 4. The sensor 5 is connected to control electronics 6 of the pump 1 which form part of frequency converter electronics of an electric motor driving the centrifugal pump 1.

[0036] The control electronics 6 are configured on the one hand to recognize the connected pressure sensor 5 as a pressure sensor and on the other hand to set the measurement range of this pressure sensor 5, as is described further below. The electrical signal of the pressure sensor 5 corresponds to a measured pressure and forms the control variable of a control loop, said control loop being part of the control electronics 6 and whose correcting variable is varied by way of corresponding activation of the pump 1.

[0037] As the circuit diagram according to FIG. 2 illustrates, the pressure sensor 5 comprises a sensor element 7, whose output signal 14 is processed by way of sensor electronics 8, whose output forms the actual sensor signal 9.

[0038] Here, the sensor signal 9 is a voltage signal, wherein a certain pressure value is assigned to each voltage value, depending on the measurement range. Part of the sensor electronics 8 is the part 10 which is symbolized in FIG. 2 and which is represented in detail in FIG. 5 and which after setting a measurement range, serves for adapting the offset 11/bias 11 and the amplification 12. The sensor signal which is transferred from the sensor electronics 8 to the control electronics 6 is characterized at 9 in FIG. 2.

[0039] A control signal is characterized at 13. This is the signal 13 which is sent from the control electronics 6 to the sensor electronics 8, for setting the measurement range as well as the offset 11 or bias 11 and the amplification 12. Even if the sensor electronics 8 are assigned to the pressure sensor 5, as is described and represented by way of FIG. 2, these sensor electronics or at least parts thereof can also be assigned to the control electronics 6.

[0040] By way of example, an adaptation of the measurement range of the pressure sensor 5 is represented by way of FIG. 3. The sensor element 7 delivers a voltage signal in the millivolt range, depending on the pressure which prevails at the sensor element 7 and which can lie between 0 and 10 bar. As the curvature of the curve 15 representing the characteristic curve of the sensor element, thus the relation between pressure and voltage of the sensor element signal 14 illustrates, the course of the signal is not linear over the measurement range. This is compensated by way of the sensor electronics 8. The offset 11 of the sensor element signal 14 which lies at a few millivolts is likewise compensated by way of the sensor electronics 8. The sensor electronics 8 moreover amplifies the measurement signal, so that a signal which corresponds to the curve 16, lies between 0 and 10 Volts and to which a pressure between 0 and 10 bar is linearly assigned, results at the output of the sensor electronics 8, thus at the output of the pressure sensor 5. The curve 16 thus forms the characteristic curve of the sensor 5.

[0041] After the connection of the sensor 5 onto the control electronics 6, and the identification and registration of the sensor 5 in the control electronics, the sensor signal 9 is continuously detected and stored after starting operation of the pump. Alternatively, this can also only be effected at temporal intervals, by way of the sensor signal being enquired and stored for example every five seconds. This is effected over a predefined time of for example two hours, two days or the like. This predefined time can be set on the part of the control electronics. Thereby, the storage of the sensor signal 9 is preferably only effected with regard to the maximal and minimal values. Here therefore, a register for the maximal value and a register for the minimal value are sufficient, wherein in each case it is examined as to whether the current (currently present) sensor signal exceeds the registered maximal value or falls short of the registered minimal value. In this case, the register is replaced by the current sensor signal, otherwise it remains unchanged. After the completion of the predefined time, the register values, as the case may be with a safety margin, are used for setting the measurement range. This measurement range which is determined on the part of the control electronics 6 is transmitted into the sensor electronics 18 by way of a control (command) signal 13.

[0042] With the embodiment example represented by way of FIG. 4, voltages between 1.1 volts and 2.72 volts (corresponding to curve 19) have been determined in the first time interval (in the predefined time) after starting operation. The measurement range as a result of this is then set to 1 to 3 bar on the basis of these values, after taking into account a 10% safety margin, wherein the sensor electronics 8 are adapted such that a linear signal course between 0 to 10 volts of the sensor signal 9 is produced in the pressure range between 1 bar and 3 bar. As the curve 17 shows, not only has the measurement range been set on the basis of the previously determined sensor signals 9, but the offset 11 has also been adapted, which is to say that the curve 17 has been adapted such that a 0 volt sensor signal corresponds to a pressure of 1 bar at the sensor element 7. Moreover, the amplification 12 has been adapted such that the voltage range between 0 and 10 volts which the sensor electronics 8 can produce, has being divided linearly onto the measurement range of 2 bar, specifically between 1 bar and 3 bar.

[0043] This adaptation process from curve 16 to curve 17 is effected by the control electronics 6 of the pump 1, in dependence on the sensor signals 9 received within a predefined time.

[0044] This procedure is repeated automatically by the control electronics 6 after the completion of the predetermined time intervals, wherein then basically three possibilities are given: [0045] 1. The register values have remained the same, and then no change of the measurement range is effected. [0046] 2. If the register values have risen with regard to the minimal value and/or have dropped with regard to the maximal value, then a corresponding adaptation of the measurement range into a smaller measurement range is effected. The offset 11 and the amplification 12 are adapted accordingly. [0047] 3. If however the registers have a value in the region of the here 10% safety margin, then the initial method for setting the measurement range is repeated as initially described.

[0048] One can differentiate yet further by temporally acquiring readings, which is to say be way of a temporal spreading the registers, by way of it not only being determined on the part of the register as to what the maximal value and the minimal value is, but over what temporal duration, with respect to the time interval, these values have been attained. Thus for example one can specify an initial reading adaptation only being effected when the maximal value and/or the minimal value has been reached over at least 5% of the interval time, when brief peaks which lie outside the set measurement range, can be tolerated with regard to the measuring accuracy of the remaining readings.

[0049] A sensor element signal 14 over time, a thereby resulting sensor signal 9 over time, as well as a measuring signal course resulting after the subsequently effected setting of the measurement range as well as the offset adaptation and amplification adaptation, are represented by way of example by way of FIG. 4. The curve 18 which shows a temporal course of the sensor element 14 over 3.5 minutes, results in signal magnitudes between 15 and 28 millivolts. This sensor element signal 14 according to curve 18, as described beforehand, is linearized and amplified by way of the sensor electronics 8, so that a signal course according to curve 19 results, with which the sensor signal 9 moves in the voltage range between 1.1 and 2.72 volts over the represented time of 3.5 minutes. The previously described setting of the measurement range, the adaptation of the offset 11 as well as the amplification 12 is then effected after completion of this time interval, with the knowledge of the maximum and minimum of the signal course over this time interval (the predefined time), so that a curve 20 results and this curve utilizes the complete signal range between 0 and 10 volts and has thus undergone an application-specific adaptation which significantly increases the measuring accuracy.

[0050] Thereby, the adaptation and setting of the measurement range is effected in a manner such that the minimal value of 1.1 volts which is reached at roughly 2 minutes on the curve 19 represents the zero point of the curve 20, and the maximal value at the point on time 2.5 of the curve 19 which lies at approx 2.72 volts is represented by a maximal value of 10 volts of the sensor signal 9.

[0051] An initial setting of the measurement range is to be understood as the setting of the measurement range which is carried out for the first time in an automatic manner by the control electronics 6 of the pump 1. Such a renewed initial setting of the measurement range, as described further above, can be necessary if, on the basis of the readings detected in a time interval, it results that the measurement range needs to be widened.

[0052] The setting of the predefined time after the completion of which such an initial measurement range setting of the control electronics 6 is effected, can be adjusted, just as the time of the subsequent time intervals, after which the measurement range is examined. The registration of the sensor can also take its course in the pump electronics in a fully automatic or partly automatic manner, and inputs are likewise necessary for the latter procedure. These inputs can other be effected at the pump itself, which is to say typically at buttons or other key elements which are provided on the control electronics housing for this, but preferably however in a wireless manner by way of an input device, for example by way of a smartphone or tablet and in a software-assisted manner, by way of a corresponding app being started on the input appliance, said app enquiring these inputs in a targeted manner and transferring them to the control unit. Such a wireless data transmission, in a direct form or also indirectly via an external server whilst utilizing a cloud-based data bank, is nowadays counted as belonging to the state of the art and are is therefore not described in detail.

[0053] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.