Pump control method and device

Abstract

One aspect of the present invention relates to a pump control unit (1) for controlling a pump (P1). The pump (P1) has a pump drive motor (2), a pump type identification device (5) for identifying a pump type, and a pump speed rating identification device (6) for identifying a pump speed rating. The pump control unit (1) includes at least one controller (10) configured to control an inverter (11) for supplying power to the pump drive motor (2), a pump type identification circuit (11), and a pump speed rating identification circuit (12). The pump type identification circuit (11) is configured to communicate with the pump type identification device (5) to identify the pump type, and the pump type identification circuit (11) is configured to output a pump type identification signal (PUMP_ID_MON) for identifying the pump type. The pump speed rating identification circuit (12) is configured to communicate with the pump speed rating identification device (6) to identify the pump speed rating, and the pump type identification circuit (11) is configured to output a pump speed rating identification signal (PUMP_SPEED_ID_MON) for identifying the pump speed rating. The controller (10) has a cross-check circuit (13) for receiving the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON). The cross-check circuit (13) is configured to identify a mismatch between the identified pump type and the identified pump speed rating. The cross-check circuit (13) is configured to output a mismatch signal (ID_CROSS-CHECK), which inhibits operation of the pump based on the identification of the mismatch. Aspects of the present invention also relate to a pump (P1) and a method of controlling the pump (P1).

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a pump control unit, a pump system, a pump device, and a pump control method. [Background technology]

[0002] Pumps for pumping process gases, such as turbomolecular pumps (TMPs), may be used in harsh operating environments. For example, pumps may be exposed to high levels of ionizing radiation, which requires the use of appropriately robust materials. In view of the harsh operating environment, it has been recognized that it is advantageous to utilize a pump controller that is remote from the pump system. The pump controller can be located in a benign environment that is not exposed to high levels of ionizing radiation. Active electronics within the pump controller, such as microcontrollers and silicon-based integrated circuits, can be protected from damage resulting from exposure to ionizing radiation that may otherwise be life threatening. The connection between the remote turbomolecular pump and the associated pump controller can consist of a power connection and a cable for signals. Power and signals can be combined in certain applications.

[0003] Standard turbomolecular pumps typically provide integrated control electronics within the pump system itself. The functional safety elements are provided by electronics specifically designed for the pump system. As a result, there is no risk of mismatching the functional safety components with an incorrect pump system, as the mechanical integration of the pump controller within the pump system prevents mismatching of the functional safety components with the pump system.

[0004] Deployments where the pump controller is located remotely from the pump, for example at a large physical distance (e.g. up to 200 m), can present certain technical challenges. In particular, maintaining the functional safety of the pump can be problematic. For high speed pump systems such as turbomolecular pumps, a particular problem is operating the turbomolecular pump above its rated speed. This can lead to mechanical failure, and in some cases, failure of the vacuum seals, or mechanical failure. These problems can be exacerbated if the pump controller is configured to control several different pumps. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to address one or more of the shortcomings associated with the prior art. [Means for solving the problem]

[0006] Aspects and embodiments of the present invention provide a pump control unit, a pump system, a pump apparatus and a method of controlling a pump as set out in the accompanying claims.

[0007] According to one aspect of the present invention, there is provided a pump control unit for controlling a pump, the pump comprising a pump drive motor, a pump type identification device for identifying a pump type, and a pump speed rating identification device for identifying a pump speed rating, the pump control unit comprising: at least one controller configured to control an inverter for supplying power to the pump drive motor; a pump type identification circuit configured to communicate with the pump type identification device to identify a pump type, the pump type identification circuit configured to output a pump type identification signal for identifying the pump type; a pump speed rating identification circuit configured to communicate with the pump speed rating identification device to identify a pump speed rating, the pump type identification circuit configured to output a pump speed rating identification signal to identify the pump speed rating; a cross-check circuit for receiving the pump type identification signal and the pump speed rating identification signal and for identifying a mismatch between the identified pump type and the identified pump speed rating; In at least certain embodiments, the cross-check circuit is configured to output a mismatch signal to inhibit operation of the pump based on the identification of a mismatch.

[0008] In at least certain implementations, the pump control unit can provide a multi-level hardware detection scheme for identifying remote pump systems prior to operation, which can optionally be configured to implement an overspeed protection system to help avoid operation of the pump at speeds above its speed rating, thereby providing an improved functional safety element for the overall pump system.

[0009] The pump control unit can identify a particular variant of the pump system. The identified variant can be cross-checked with the secondary pump speed rating identification signal. The pump control unit can thereby ensure that the identified pump type and the identified pump speed rating match. In at least certain embodiments, the pump control unit can be configured to enable operation of the pump based on identifying a match between the identified pump type and the identified pump speed rating.

[0010] The pump type identification circuit and the pump speed rating identification circuit can be implemented as two dedicated hardware detection circuits. The pump identification and the pump speed rating can be identified via two signals, for example, a first and a second analog voltage signal. The two signals can be used by a cross-check circuit to verify that a valid pump system is detected. To achieve a high protection level (PL), the primary functional safety element can be achieved exclusively by hardware electronics.

[0011] The pump control unit may perform complementary checks on the pump type identification signal and the pump speed rating signal, for example via embedded firmware. These checks may enable diagnostics and / or complementary protection. For example, operation of the pump may be inhibited based on detection of an inconsistency by the firmware. The firmware checks may be complementary to the hardware checks described herein.

[0012] In at least certain embodiments, the pump control unit can provide one or more of the following advantages. A hardware-based solution that provides redundancy to achieve increased reliability, thus enabling a high Protection Level (PL) rating. A hardware-based solution that provides a well-defined platform for evaluating reliability designs for functional safety. Cost-effective solution allows pump systems to be categorized by speed range, reducing design complexity and part count.

[0013] The crosscheck circuit can be configured to output a mismatch signal to a trip latch circuit to inhibit operation of the pump. In at least certain embodiments, the trip latch circuit can be configured to inhibit operation of the inverter.

[0014] The pump type identification circuit can be configured to output a first current to the pump type identification circuit and measure a pump type identification voltage. The pump type identification circuit can be configured to identify the pump type based on the measured pump type identification voltage.

[0015] The pump speed rating identification circuit can be configured to output a second current to the pump speed rating identification circuit and measure a pump speed rating identification voltage. The pump speed rating identification circuit can be configured to identify the pump speed rating based on the measured pump speed rating identification voltage.

[0016] The cross-check circuit can be configured to identify a mismatch based on a determination that the measured pump type identification voltage and the measured pump speed rating identification voltage differ from one another. The cross-check circuit can be configured to identify a mismatch based on a determination that a relationship between the measured pump type identification voltage and the measured pump speed rating identification voltage is outside a predetermined range.

[0017] At least one controller can be configured to receive a pump type identification signal and a pump speed rating identification signal.

[0018] The at least one controller can be configured to perform a secondary check to identify a mismatch between the identified pump type and the identified pump speed rating based on the pump type identification signal and the pump speed rating identification signal.

[0019] The or each controller comprises at least one electronic processor and a memory device. A set of computer instructions may be stored in the memory device. When executed by the at least one electronic processor, the computer instructions cause the at least one electronic processor to perform the methods described herein. In particular, the computer instructions cause the at least one electronic processor to identify a second inconsistency.

[0020] The at least one controller may be configured to inhibit operation of the pump based on identifying the inconsistency.

[0021] The at least one controller can be configured to control an operating speed of the pump based on the identified pump speed rating.

[0022] The pump control unit may include an overspeed detection unit, which may be configured based on the pump speed rating identification signal.

[0023] According to a further aspect of the present invention there is provided a pump system comprising a pump control unit as herein described.The pump system may comprise a pump device.

[0024] According to a further aspect of the present invention, Pump drive motor; A pump type identification device for identifying the pump type; and a pump speed rating identification device for identifying a pump speed rating; wherein the pump type identification device and the pump speed rating identification device are operable independently of each other to identify the pump type and the pump speed rating, respectively.

[0025] The pump type identification device may include a pump type resistor network for establishing a pump type identification voltage independent of the supply of the first current.

[0026] The pump speed rating identification device may include a speed rating resistor network for establishing a pump speed rating identification voltage independent of the supply of the second current.

[0027] According to a further aspect of the present invention there is provided a pump control unit for controlling operation of a pump comprising a pump drive motor, a pump type identification device and a pump speed rating identification device, the pump control unit comprising: communicating with the pump type identification device to determine the pump type; communicating with the pump speed rating identification device to determine the pump speed rating; Cross-check the determined pump type and the determined pump speed rating, inhibiting operation of the pump based on identifying a mismatch between the determined pump type and the determined pump speed rating; The pump controller may be configured to enable operation of the pump based on identifying a match between the determined pump type and the determined pump speed rating.

[0028] According to a further aspect of the present invention there is provided a method of controlling a pump having a pump drive motor, a pump type identification device, and a pump speed rating identification device, the method comprising: communicating with a pump type identification device to determine a pump type; communicating with a pump speed rating identification device to determine a pump speed rating; cross-checking the determined pump type and the determined pump speed rating; inhibiting operation of the pump based on identifying a mismatch between the determined pump type and the determined pump speed rating; The method may include enabling operation of the pump based on identifying a match between the determined pump type and the determined pump speed rating.

[0029] A control unit or controller as described herein may suitably comprise a computing device having one or more electronic processors. A system may comprise a single control unit or electronic controller, or alternatively, different functions of a controller may be embodied in or hosted in different control units or controllers. The term "controller" or "control unit" as used herein is understood to include both a single control unit or controller and multiple control units or controllers that collectively operate to provide any described control function. To constitute a controller or control unit, a suitable set of instructions may be provided that, when executed, causes the control unit or computing device to implement the control techniques identified herein. The set of instructions may suitably be embedded in one or more electronic processors. Alternatively, the set of instructions may be provided as software stored in one or more memories associated with the controller for execution on the computing device. A control unit or controller may be implemented as software running on one or more processors. One or more other control units or controllers may be implemented as software running on one or more processors, optionally the same one or more processors as the first controller. Other suitable configurations may also be used.

[0030] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, alternatives, and in particular their individual features described in the preceding paragraphs, claims and / or in the following description and drawings, can be construed independently or in any combination. That is, any embodiment and / or feature can be combined in any manner and / or combination, unless these features are incompatible. The applicant reserves the right to modify the claims originally filed or to submit new claims thereon, including the right to amend the claims originally filed to rely on and / or incorporate features of other claims, even if they were not originally claimed as such.

[0031] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings. [Brief description of the drawings]

[0032] [Figure 1] 1 shows a schematic diagram of a pump control unit according to one embodiment of the present invention. [Diagram 2] FIG. 1 shows a schematic diagram of a pump control unit with a controller. [Diagram 3] A schematic diagram of the controller shown in Figure 2 is shown. [Figure 4] 1 shows a circuit diagram of a pump type identification circuit provided in a pump control unit for communicating with an on-board pump type identification device. [Diagram 5] 1 shows a circuit diagram of a pump speed rating identification circuit provided in a pump control unit for communicating with an on-board pump speed rating identification device. [Figure 6] 1 shows a schematic diagram of a cross-check circuit provided in a pump control unit to compare pump types and pump speed ratings. [Figure 7] 1 shows a circuit diagram of an overspeed circuit provided in a pump control unit for identifying pump overspeed. [Figure 8]1 shows a circuit diagram of an overspeed trip circuit provided in the pump control unit for inhibiting operation of the first pump. [Figure 9] 1 shows a circuit diagram of a latch circuit provided in the pump control unit for inhibiting operation of the first pump. [Figure 10] FIG. 4 shows a flow diagram illustrating the operation of a pump control unit according to an embodiment of the present invention. [Figure 11] 4 shows first and second tables representing state conditions for pump type identification and pump speed rating identification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] A pump control unit 1 according to an embodiment of the present invention is described herein with reference to the accompanying drawings. The pump control unit 1 is configured to control a first pump P1 having a pump drive motor 2. The pump control unit 1 and the first pump P1 together form a pump system.

[0034] The pump control unit 1 in this embodiment is selectively configured to control the operation of a plurality of different pumps Pn. The pumps Pn may be of different types (referred to herein as pump types) and / or have different speed ratings. The different pump types may be variations of the same pump Pn or may be different pumps Pn. The different types of pumps Pn may have different mechanical and / or electrical operating parameters. As an example, the air gap flux may be different depending on the type of the pump drive motor 2. The speed rating may, for example, define the full load speed rating of the pump drive motor 2. The different speed ratings may have different mechanical and / or electrical operating parameters. As described herein, the pump control unit 1 is configured to modify the control function based on the determined pump type and / or speed rating. The pump control unit 1 may also control diagnostic feedback based on the determined pump type and / or speed rating.

[0035] As shown in FIG. 1 , the pump control unit 1 is described herein with reference to a first pump P1. The first pump P1 is a first pump type and has a first speed rating. The pump control unit 1 is separate from the first pump P1. The pump control unit 1 in this embodiment is remote from the first pump P1 and provides remote control of the first pump P1. The pump control unit 1 is electrically connected to the first pump P1 by power and signal cables. The pump control unit 1 is operative to determine a pump type and a pump speed rating of the first pump P1. As described herein, the pump control unit 1 is configured to select an appropriate control strategy for controlling the operation of the first pump P1 based on the determined pump type and pump speed rating. The control scheme may be selected from a plurality of predefined control schemes.

[0036] The first pump P1 in this embodiment is a vacuum pump for establishing a vacuum in an industrial process. In use, the first pump P1 is configured to pump a process gas. The first pump P1 may be, for example, a turbomolecular pump. The first pump P1 comprises a pump drive motor 2, a pump type identification device 5, and a pump speed rating identification device 6. The pump drive motor 2 is a permanent magnet (PM) electric motor. As shown diagrammatically in FIG. 1, the pump drive motor 2 comprises a rotor 7 and a stator 8. The pump type identification device 5 and the pump speed rating identification device 6 may be integrated in the first pump P1. A three-phase alternating current is supplied to the electric motor 2 from an inverter 9. As described herein, the inverter 9 is controlled by a pump control unit 1. A schematic diagram of the pump control unit 1 is shown in FIG. 2. The pump control unit 1 comprises a controller 10, as shown in FIG. 3.

[0037] The pump type identification device 5 is provided to enable the pump control unit 1 to identify the pump type of the first pump P1. The pump type identification device 5 is implemented in hardware as a circuit. The pump type identification device 5 is configured to enable the pump control unit 1 to distinguish between two or more different pump types. The pump control unit 1 communicates with the pump type identification device 5 to identify the first pump P1 as being of the first pump type. The pump type identification device 5 enables the pump control unit 1 to distinguish between the first pump type and at least one second pump type. The pump type identification device 5 comprises a pump type resistor network TRN1 consisting of one or more electrical resistors. The resistors are provided on a printed circuit board located in the first pump P1. The printed circuit board and the passive components are referred to as a pump electronic printed circuit assembly (pump electronic PCA). The pump type resistor network TRN1 has identifiable predefined pump type resistors. The pump type resistors are predefined and associated with the first pump type. Each pump Pn has a pump type identification device 5 comprising a pump type resistor network TRN1 with an associated pump type resistor. The pump type resistor is predefined and different for each pump type. The pump type resistor is selected to provide sufficient tolerance and range banding, for example to allow cable lengths up to 200 meters. The pump type resistors are capable of identifying eight or more different pump types. The pump control unit 1 can identify the pump type by measuring a pump identification voltage (PUMP_ID) across the pump type resistor network TRN1 to determine the pump type resistance. For example, a second pump P2 of a second type can be provided with a second pump type resistor network having a second pump type resistance, the second pump type resistance being different from the first pump type resistance.

[0038] The first pump P1 has a first speed rating. The speed rating may, for example, define the full load speed rating of the first pump P1. If the first pump P1 is operated above the rated speed, there is a risk of mechanical failure, which may result in failure of the vacuum seal. A pump speed rating identification device 6 is provided to enable the pump control unit 1 to identify the speed rating of the first pump P1. The pump speed rating identification device 6 is implemented in hardware as an electric circuit. The pump speed rating identification device 6 may have the same configuration as the pump type identification device 5. The pump speed rating identification device 6 enables the identification of the speed rating of the first pump P1 as one of a plurality of different speed ratings. In particular, the pump type identification device 5 enables the pump control unit 1 to identify the first pump P1 as having a first speed rating. For example, different pumps Pn available in a particular range may have different speed ratings. The pump speed rating identification device 6 enables the distinction between the speed rating of the first pump P1 and the speed ratings of the other pumps Pn. The pump speed rating identification device 6 comprises a speed rating resistor network SRN1 consisting of one or more electrical resistors. The resistors are provided on a printed circuit board located in the first pump P1. The speed rating resistor network SRN1 may be integrated into a pump electronics printed circuit board assembly (pump electronics PCA). The pump type resistor network TRN1 and the speed rating resistor network SRN1 are independent of each other. The speed rating resistor network SRN1 has a predefined identifiable speed rating resistance. The first speed rating resistance is predefined and associated with the first pump speed rating. Each pump Pn comprises a pump speed rating identification device 6 and comprises a speed rating resistor network SRN1 having a speed rating resistance. The speed rating resistance is predefined and different for each speed rating. The speed rating resistance value is selected to provide sufficient tolerance and range band, for example to allow cable lengths up to 200 meters. The pump type resistor is capable of identifying four or more different pump speed ratings.The pump control unit 1 can identify the pump speed rating and determine the pump type resistance by measuring a pump speed identification voltage (PUMP_SPEED_ID) voltage across the speed rating resistor network SRN1. As an example, the second pump P2 can include a second pump type resistor network having a second speed rating resistance, where the second speed rating resistance is different from the first speed rating resistance.

[0039] As shown in FIG. 2, the pump control unit 1 includes a controller 10, a pump type identification circuit 11, a pump speed rating identification circuit 12, a cross-check circuit 13, a pump overspeed circuit 14, and a trip latch circuit 15. The controller 10 is configured to control the operation of the inverter 9 to control the operation of the pump drive motor 2. In particular, the controller 10 is configured to select and implement a control strategy for the pump drive motor 2 based on the determined pump type and pump speed rating. As shown in FIG. 3, the controller 10 includes at least one electronic processor 16 and a system memory 17. A set of computer instructions is stored in the system memory 17. When executed, the computer instructions cause the electronic processor 16 to implement the methods described herein. The controller 10 is configured to communicate with the pump type identification circuit 11, the pump speed rating identification circuit 12, the cross-check circuit 13, and the pump overspeed circuit 14. The pump type identification circuit 11 and the pump speed rating identification circuit 12 are implemented in hardware as separate circuits. The operation of the pump control unit 1 will be described in more detail below with reference to the accompanying drawings.

[0040] The pump type identification circuit 11 is configured to communicate with the pump type identification device 5 to identify the pump type. The pump type identification circuit 11 is implemented in hardware. A second circuit diagram 200 representing the pump type identification circuit 11 is shown in FIG. 4. The pump type identification circuit 11 is configured to output a pump type identification signal to the pump type identification device 5. The pump type identification signal includes a predetermined current generated by a current source. The pump type identification signal is injected into a pump type resistor network TRN1 provided in the pump type identification device 5. A voltage measured across the pump type resistor network TRN1 is used to determine a pump type resistance of the pump type resistor network TRN1. The pump type resistance is unique for each pump type. This allows the pump type identification circuit 11 to identify the pump type based on the measured voltage. The pump type identification circuit 11 outputs a pump type identification signal (PUMP_ID_MON) for identifying the pump type. In this embodiment, the pump type identification signal (PUMP_ID_MON) indicates a voltage measured across the pump type resistor network TRN1. The pump type identification signal (PUMP_ID_MON) is output to the controller 10 and the cross-check circuit 13. In this embodiment, the pump type identification circuit 11 identifies the first pump P1 as being of a first pump type.

[0041] The pump speed rating identification circuit 12 is configured to communicate with the pump speed rating identification device 6 to identify the pump speed rating. The pump speed rating identification circuit 12 is implemented in hardware. A third circuit diagram 300 representing the pump speed rating identification circuit 12 is shown in FIG. 5. The pump speed rating identification circuit 12 is configured to output a pump speed rating identification signal to the pump speed rating identification device 6. The pump speed rating identification signal includes a predetermined current generated by a current source. The pump speed rating identification signal is injected into a pump speed rating resistor network SRN1 provided in the pump speed rating identification device 6. A voltage measured across the pump speed rating resistor network SRN1 is used to determine a pump speed rating resistance of the pump speed rating resistor network SRN1. The pump speed rating resistance is unique for each pump speed rating. This allows the pump speed rating identification circuit 12 to identify the pump speed rating based on the measured voltage. The pump speed rating identification circuit 12 outputs a pump speed rating identification signal (PUMP_SPEED_ID_MON) for identifying the pump speed rating. The pump speed rating identification signal (PUMP_SPEED_ID_MON) in this embodiment indicates the voltage measured across the pump speed rating resistor network SRN1. The pump speed rating identification signal (PUMP_SPEED_ID_MON) is output to the controller 10 and to the crosscheck circuit 13. In this embodiment, the pump speed rating identification circuit 12 identifies that the first pump P1 has a first pump speed rating.

[0042] The cross-check circuit 13 is configured to determine whether there is a valid match between the pump type identified by the pump type identification circuit 11 and the pump speed identified by the pump speed rating identification circuit 12. The cross-check circuit 13 is implemented in hardware. A fourth circuit diagram 400 representing the cross-check circuit 13 is shown in FIG. 6. The cross-check circuit 13 receives a pump type identification signal (PUMP_ID_MON) from the pump type identification circuit 11 and a pump speed rating identification signal (PUMP_SPEED_ID_MON) from the pump speed rating identification circuit 12. The cross-check circuit 13 compares the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON) to determine whether there is a match between the pump type identified by the pump type identification circuit 11 and the pump speed identified by the pump speed rating identification circuit 12. The cross-check circuit 13 performs a hardware check using a window comparator to identify a match or mismatch. The measured pump identification voltage is used by the cross-check circuit 13 together with the pump speed identification voltage to determine whether the first pump P1 has been correctly identified. This analysis is performed before operation of the first pump P1 and helps ensure safe operation. The pump identification voltage and the pump speed identification voltage must match or fall within a defined range before and during operation of the first pump P1. If the cross-check circuit 13 determines that there is a match between the identified pump type and the pump speed rating, a match signal is output to the controller 10. If the cross-check circuit 13 determines that there is a mismatch between the identified pump type and the pump speed rating, a mismatch signal is output to the controller 10. The cross-check circuit 13 is configured to output a mismatch signal (ID_CROSS-CHECK) to inhibit operation of the pump P1 based on the identification of a mismatch. The mismatch signal (ID_CROSS-CHECK) is output to the controller 10 and the trip latch circuit 15. Only a valid match before and during operation leads to power being supplied to the first pump P1.If the cross-check circuit 13 determines that the identified pump type and pump speed rating are not a valid match, the trip latch circuit 15 controls the inverter 9 to inhibit power to the pump drive motor 2 .

[0043] The pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON) are output to the controller 10. The at least one processor 16 is configured to control the operation of the first pump P1 based on the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON). The at least one processor 16 can provide functional performance and / or diagnostic feedback based on, for example, the pump type identified by the pump type identification signal (PUMP_ID_MON). The functional performance can define, for example, one or more parameters for estimating the air gap flux in the pump drive motor 2. The functional performance and / or diagnostic feedback can be matched to the identified pump type. Different functional performance and / or diagnostic feedback can be provided for different pump types. The controller 10 can control the operating speed of the first pump P1 based on the speed rating identified by the pump speed rating identification signal (PUMP_SPEED_ID_MON). For example, the controller 10 may determine an upper speed threshold based on the identified pump speed rating. The controller 10 may optionally be configured to perform a secondary check using embedded firmware to identify a match or mismatch between the pump type identified by the pump type identification signal (PUMP_ID_MON) and the pump speed rating identified by the pump speed rating identification signal (PUMP_SPEED_ID_MON). The controller 10 may control the inverter 9 to inhibit power to the pump drive motor 2 if the secondary check identifies a mismatch. In at least certain embodiments, operation of the first pump P1 may be inhibited unless both the controller 10 and the cross-check circuit 13 identify a valid match between the pump type and the pump speed rating.

[0044] The pump speed rating identification signal (PUMP_SPEED_ID_MON) is output to the pump overspeed circuit 14. The pump overspeed circuit 14 is implemented in hardware. A fifth circuit diagram 500 representing the pump overspeed circuit 14 is shown in FIG. 7. The pump speed rating is used to configure the overspeed circuit 14 to control the operating speed of the first pump P1. The voltage measured across the pump speed rating resistor network SRN1 is used to configure the pump overspeed trip circuit 18. The pump overspeed trip circuit 18 is implemented in hardware. A sixth circuit diagram 600 representing the pump overspeed trip circuit 18 is shown in FIG. 8. The voltage measured across the pump speed rating resistor network SRN1 is used to configure a dedicated current source that sets the interval timer of the pump overspeed circuit 14. The pump overspeed circuit 14 and the pump overspeed trip circuit 18 are implemented as separate circuits in this embodiment. In a variant, the pump overspeed circuit 14 and the pump overspeed trip circuit 18 can be coupled to each other.

[0045] The trip latch circuit 15 is implemented in hardware. A seventh circuit diagram 700 representing the trip latch circuit 15 is shown in Figure 9. The trip latch circuit 15 is configured to inhibit operation of the first pump P1 based on identification of a mismatch by either the controller 10 or the crosscheck circuit 13.

[0046] The operation of the pump control unit 1 will now be described with reference to a flow diagram 800 shown in FIG. 10. The pump control unit 1 is connected to the first pump P1 using power and signal cables (block 805). The pump type identification circuit 11 and the pump speed rating identification circuit 12 are provided on board the first pump P1. The pump control unit 1 determines the pump type by interrogating the pump type identification circuit 11 (block 810). The pump control unit 1 determines the pump speed rating of the first pump P1 by interrogating the pump speed rating identification circuit 12 (block 815). The cross-check circuit 15 compares the determined pump type with the pump speed rating and determines whether there is a valid match or a mismatch (i.e., an invalid match) (block 820). If the cross-check circuit 15 detects a mismatch, the operation of the first pump P1 is inhibited (block 825). In this embodiment, the trip latch circuit 15 operates to inhibit the operation of the first pump P1. The pump control unit 1 can optionally output a mismatch signal to alert an operator of a mismatch between the pump type and the pump speed rating. If the cross-check circuit 15 determines that there is a valid match, operation of the first pump P1 is enabled (block 830). The pump control unit 1 controls the first pump P1 based on the determined pump speed rating. For example, the pump control unit 1 can limit the operating speed of the first pump P1 to match the pump speed rating (block 835). Operation of the first pump P1 is terminated in a conventional manner (block 840).

[0047] In at least certain embodiments, the pump control unit 1 can be used to safely control a number of different pumps Pn. Each pump Pn includes a pump type identification circuit 11 and a pump speed rating identification circuit 12. The pump control unit 1 injects a predetermined current into the pump type identification circuit 11 and the pump speed rating identification circuit 12. The measured voltage indicates the pump type and pump speed rating of the pump Pn. The pump control unit 1 utilizes a cross-check circuit 15 to ensure that the pump type and pump speed rating match. If there is no valid match between the pump type and the pump speed rating, the cross-check circuit 15 outputs a mismatch signal. The trip latch circuit 15 is configured to inhibit operation of the pump Pn upon receipt of the mismatch signal. By comparing the pump type and pump speed rating, the pump control unit 1 performs additional checks to ensure correct identification of the pump Pn. The pump control unit 1 provides hardware redundancy, an important feature in achieving high reliability of functional safety. The system uses two independent identification circuits, the pump type identification circuit 11 and the pump speed rating identification circuit 12. If any of these circuits detect an incorrect pump type or speed type, the pump control unit 1 disables output power from the pump control unit 1 to the pump Pn. Additionally, each detection circuit is designed to capture both short circuit and open circuit conditions. In at least certain embodiments, this may provide an additional level of protection. The pump control unit 1 implements an appropriate control scheme based on the identified pump Pn. For example, the pump control unit 1 may select one of a number of predefined control schemes based on the identified pump Pn.

[0048] A first table (Table A) and a second table (Table B) are shown in FIG. 11. The first table 25 represents the state conditions of the pump speed rating identification signal and the second table 30 represents the state conditions of the pump type identification signal used by the cross-check circuit 15. The combination of these state conditions should produce a LOW output signal indicating a valid match condition. If the output signal remains HIGH, a mismatch condition, i.e., a short or open condition, has been detected. It will be understood that various changes and modifications can be made to the present invention without departing from the scope of the present application.

[0049] TIFF2025511934000002.tif117153 TIFF2025511934000003.tif56153

Claims

1. A pump control unit (1) for controlling a pump (P1), comprising: The pump (P1) comprises a pump drive motor (2), a pump type identification device (5) for identifying a pump type, and a pump speed rating identification device (6) for identifying a pump speed rating; The pump control unit (1), at least one controller (10) configured to control an inverter to supply power to the pump drive motor (2); a pump type identification circuit (11) configured to communicate with the pump type identification circuit (5) to identify the pump type, the pump type identification circuit (11) being configured to output a pump type identification signal (PUMP_ID_MON) for identifying the pump type; a pump speed rating identification circuit (12) configured to communicate with the pump speed rating identification device (6) to identify the pump speed rating, the pump type identification circuit (11) configured to output a pump speed rating identification signal (PUMP_SPEED_ID_MON) for identifying the pump speed rating; a cross-check circuit (13) for receiving the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON) and for identifying an inconsistency between the identified pump type and the identified pump speed rating; Equipped with the cross-check circuit (13) is configured to output a mismatch signal (ID_CROSS-CHECK) to inhibit operation of the pump based on the identification of the mismatch. Pump control unit (1).

2. 2. The pump control unit (1) of claim 1, wherein the cross-check circuit (13) is configured to output the inconsistency signal (ID_CROSS-CHECK) to a trip latch circuit to inhibit operation of the pump.

3. A pump control unit (1) as described in claim 1 or claim 2, wherein the pump type identification circuit (11) is configured to output a first current to the pump type identification circuit (11) and measure a pump type identification voltage, and the pump type identification circuit (11) is configured to identify the pump type based on the measured pump type identification voltage.

4. 4. The pump control unit (1) of claim 1, 2 or 3, wherein the pump speed rating identification circuit (12) is configured to output a second current to the pump speed rating identification circuit (12) to measure a pump speed rating identification voltage, and the pump speed rating identification circuit (12) is configured to identify the pump speed rating based on the measured pump speed rating identification voltage.

5. 5. The pump control unit (1) of claims 3 and 4, wherein the cross-check circuit (13) is configured to identify a mismatch based on a determination that the relationship between the measured pump type identification voltage and the measured pump speed rating identification voltage is outside a predetermined range.

6. The pump control unit (1) according to any one of claims 1 to 5, wherein the at least one controller (10) is configured to receive the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON).

7. The pump control unit (1) of claim 6, wherein the at least one controller (10) is configured to perform a secondary check to identify an inconsistency between the identified pump type and the identified pump speed rating based on the pump type identification signal (PUMP_ID_MON) and the pump speed rating identification signal (PUMP_SPEED_ID_MON).

8. 8. The pump control unit (1) of claim 7, wherein the at least one controller (10) is configured to inhibit operation of the pump upon identification of the inconsistency.

9. 9. The pump control unit (1) of claim 6, 7 or 8, wherein the at least one controller (10) is configured to control an operating speed of the pump based on the identified pump speed rating.

10. A pump control unit (1) according to any one of the preceding claims, comprising an overspeed detection unit configured on the basis of said pump speed rating identification signal (PUMP_SPEED_ID_MON).

11. A pump system comprising a pump control unit (1) according to any one of claims 1 to 10 and a pump device (P1).

12. A pump device (P1), A pump drive motor (2); a pump type identification device (5) for identifying the pump type; a pump speed rating identification device (6) for identifying the pump speed rating; Equipped with A pump arrangement (P1), wherein said pump type identification device (5) and said pump speed rating identification device (6) are operable independently of each other to identify said pump type and said pump speed rating, respectively.

13. 13. The pump arrangement (P1) according to claim 12, wherein the pump type identification device (5) comprises a pump type resistor network for establishing a pump type identification voltage independent of the supply of the first current.

14. 14. Pump arrangement (P1) according to claim 12 or 13, wherein the pump speed rating identification device (6) comprises a speed rating resistor network for establishing a pump speed rating identification voltage based on the supply of a second current.

15. A method for controlling a pump (P1) having a pump drive motor (2), a pump type identification device (5) and a pump speed rating identification device (6), comprising: communicating with said pump type identification device (5) to determine the pump type; determining a pump speed rating in communication with said pump speed rating identification device (6); cross-checking the determined pump type and the determined pump speed rating; inhibiting operation of the pump (P1) based on an identification of a mismatch between the determined pump type and the determined pump speed rating; A method comprising:

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