Method for monitoring and controlling current distribution in a device

Abstract

This invention relates to a method for monitoring and controlling current distribution in a device. An output voltage is provided by at least one clock-controlled power supply unit and distributed to load circuits for power supply. At least a plurality of load circuits are protected by switching units operated by a control unit. During a learning phase, the current variation process of the current consumed by the corresponding load circuit is measured in at least each protected load circuit. At least one significant current distribution map, along with a tolerance range, is derived from the current variation process and assigned to the load circuits. During continuous operation of the device, the control unit continuously monitors the current variation process and checks whether the clock-controlled power supply unit has at least reached its capacity limit. When at least the capacity limit is reached, the control unit at least reduces and / or shuts off the consumed current by operating the switching units in those load circuits where the current variation process exceeds the upper limit of the tolerance range of the significant current distribution map.

Description

Technical Field

[0001] This invention generally relates to the field of electrical engineering, particularly power electronics and power electronic circuits. Specifically, the invention relates to a method for current distribution in the load circuit of a device control apparatus for monitoring and controlling technical equipment. Here, the load circuit has at least one load unit (e.g., a sensor, actuator, relay, contactor, solenoid valve, servo motor, control device, display unit, etc.). A pre-defined and constant output voltage is provided by at least one clock-controlled power supply unit and distributed to the load circuit of the device control apparatus to supply energy to the load unit. Furthermore, at least a plurality of load circuits are protected by switching units, which are operated by a control unit. Background Technology

[0002] In many fields, particularly in industrial production and manufacturing, and in automation technology, complex technical equipment and machines are now in use. Here, equipment is understood as a planned arrangement of spatially related and functionally, technically, and / or safety-related components (e.g., machines, instruments, and / or devices). For efficient operation of technical equipment, equipment control devices are typically used, through which the continuous operation of the equipment should be carried out as independently as possible and without human intervention. Since technical equipment, such as production equipment and manufacturing equipment, is rarely implemented in the same structural manner due to varying requirements, each piece of equipment, or its respective equipment control device, includes varying numbers and sizes of power-consuming or load units—such as actuators, relays, contactors, solenoid valves, servo motors, acoustic and / or optical warning signals, sensors, etc.—as well as control devices (e.g., programmable logic controllers (SPS), PC-based control devices, microcontrollers, etc.) and display units for, for example, evaluating sensor values ​​and / or manipulating actuators.

[0003] Typically, in technical equipment, multiple electrical load units of the equipment control device are combined into a power supply unit or load circuit, wherein the load circuit has at least one load unit (e.g., sensor, actuator, control device, display unit, etc.). At least one clock-controlled power supply unit (e.g., a switching power supply section) is typically used to supply power to the load units connected in the load circuit. The clock-controlled power supply unit converts the unstable input voltage (in most cases, AC voltage) into a constant output voltage (e.g., 24 volts DC voltage) with mostly predetermined values. The output voltage or output current provided by the clock-controlled power supply unit is then distributed to the corresponding load circuits of the equipment control device of the technical equipment, wherein each load circuit or separately connected load unit may have different power requirements.

[0004] However, a failure in the load unit can cause a reaction on the power supply unit. Thus, conditions such as overload, short circuit, or overcurrents similar to a short circuit, such as those occurring during motor startup due to high power demand, may trigger the shutdown of the power supply unit in the load circuit. To prevent complete equipment failure due to, for example, the shutdown of the power supply unit, the load circuit is in most cases protected against overload or short circuit at the output side of the power supply unit using protective devices, such as automatic fuses with specific triggering characteristics or line protection switches. This ensures that the overloaded load circuit is shut off and the remaining load circuits of the equipment or equipment control devices remain unaffected. However, protective devices, especially low-cost ones like circuit breakers, have large tolerances in triggering accuracy. In the event of an error, a delay (e.g., several milliseconds) may therefore occur during triggering.

[0005] Therefore, electronic fuses are increasingly used today to protect clock-controlled power supply units from adverse effects from load circuits (such as faulty load units, short circuits, overcurrents similar to short circuits, overloads, etc.). These fuses have electronic switching units (e.g., semiconductor switches) that are operated by corresponding control signals from a control unit. If one of the settable trigger parameters is exceeded, the fuse can quickly intervene in case of an error and limit and / or shut off the current in the corresponding load circuit according to the trigger parameters set by the control unit (e.g., trigger current, maximum permissible duration of overcurrent, etc.).

[0006] The dimensions of the fuses for each load circuit or load unit connected to said load circuit are typically determined during the equipment planning phase, set during the equipment implementation phase, and can be adapted, for example, during the initial commissioning of the equipment, where fuses that were initially determined to be too small or set are first readjusted. However, for time reasons, the trigger parameters of the fuses for each load circuit are often inappropriately selected. That is, for example, trigger parameters that are set too high in the case of fuses or switching units compared to what would be necessary for the corresponding load circuit or at least one of the corresponding connected load units.

[0007] Because in error conditions (e.g., short circuit, overload, etc.), the control unit no longer promptly operates the (too precisely defined) switching units located directly before the affected load circuit to limit and / or interrupt current, selective triggering of individual fuses or switching units is no longer guaranteed. Current may thus flow into the affected load circuit and consequently into at least one load unit within the load circuit, potentially causing greater damage. If necessary, backup fuses (e.g., line protection switches) trigger with a time delay, unnecessarily switching a larger area of ​​equipment to de-voltage. In the worst case, since overload or short-circuit currents may exceed the capacity of the power supply unit, the entire system fails due to overloading of the fed power supply unit caused by unexpected additional power demands.

[0008] A method is known from document WO 2010 / 018018 A1, in which the highest necessary trigger current value for continuous operation is determined for a power consumer or load unit in a technical device during an observation period, so as to adapt the trigger current value to a settable safety device. For this purpose, the current consumed by the power consumer is measured by a control unit during multiple observation time intervals. For each observation time interval, the maximum value of the measured current is determined and stored. Then, a static limit value for adapting the trigger parameter or trigger current is determined from the measured maximum value equipped with a safety reserve, for example by means of slow averaging, starting from a default value (e.g., nominal current). Here, in addition to the static limit value for continuous operation, a dynamic limit value for the power consumer's connection process can also be determined.

[0009] However, especially when multiple load units (sonic valves, servo motors, contactor coils, etc.) are simultaneously connected by multiple load circuits while the equipment is running, the sum of the set or determined values ​​of the triggering parameters, especially the triggering currents of the individual fuses or switching units that trigger to protect the load circuits, is not uncommon and significantly higher than the capacity of the power supply unit. In the method known from document WO 2010 / 018018 A1, although the triggering parameters, especially the values ​​of the triggering currents of the individual fuses used to protect each consumer are adapted to the operating conditions of the equipment, the capacity of the power supply unit and the distribution of the output current to each consumer or load circuit are hardly considered when supplying multiple connected consumer or load circuits. Furthermore, erroneous shutdown of the load circuits or load units may occur because the current consumption of each load circuit or connected load unit alone is decisive for the current value at which the switching unit of the protection device triggers. In other words, the current consumed by the load circuit is limited or shut off, even though the power supply unit still has sufficient capacity to supply it, or because the trigger value has been determined to be too low based on the historical maximum value within the observation period. This, for example, leads to at least part of the device being unnecessarily shut down. Summary of the Invention

[0010] Therefore, the objective of this invention is to describe a method that is a further development of the prior art, which enables the continuous operation of technical equipment in a simple manner and with low cost for planning the equipment, enabling the safe and error-free operation of the load circuit of the equipment, especially the equipment control device, and the power supply unit supplying the load circuit of the equipment control device.

[0011] This task is solved by a method of the type mentioned at the beginning, having the features described in the independent patent claims. Advantageous embodiments of the invention are described in the dependent claims.

[0012] According to the present invention, this task is accomplished by a method for verifying and controlling the current distribution in the load circuit of a device control apparatus of a technical device of the type mentioned above. During the learning phase, the current variation process of the current consumed by the respective load circuit is measured, at least in those load circuits protected by switching units. Then, at least one significant current distribution map and a tolerance range belonging to the circuit distribution map are derived from the current variation process measured for the respective load circuit and assigned to the respective load circuit. During continuous operation of the device, the current variation process, which is measured at least for those load circuits protected by switching units, is continuously monitored by the control unit. Furthermore, the control unit verifies whether the clock-controlled power supply unit has at least reached or exceeded its capacity limit. When the clock-controlled power supply unit has at least reached or exceeded the capacity limit, the control unit at least reduces and / or shuts off the current consumed by the respective load circuit by manipulating the switching units in those load circuits where the current variation process currently measured for the respective load circuit exceeds the upper limit of the tolerance range of the significant current distribution map assigned to the respective load circuit.

[0013] The main aspect of the solution proposed according to the invention is that, as long as the clock-controlled power supply unit does not reach or exceed its capacity limit, it provides the load circuit of the device control device with the same amount of current or energy required by the corresponding load circuit or by at least one load unit belonging to the corresponding load circuit during continuous operation at the current point in time. When the capacity limit is reached or exceeded, the current is reduced and / or shut off by correspondingly manipulating the switching units in those load circuits that consume current beyond normal or common limits or exhibit “obvious” current behavior. The normal or common limit power demand of the corresponding load circuit is determined using the tolerance range based on the current distribution diagram determined for the corresponding load circuit during the learning phase. Therefore, it is no longer necessary to determine appropriate trigger values ​​for the switching units used for protection of the load circuits protected by the switching units, where the current is reduced and / or shut off in the corresponding load circuits. Instead, the capacity of the power supply unit providing the supply is used as a limiting factor. This ideally prevents missetting during equipment planning or installation, especially setting the trigger values ​​of switching units that function as electronic safety devices too high. Furthermore, the static and dynamic current behavior of the load circuits are considered in a combined manner, as well as the distribution of the output current of the power supply unit to each load circuit and its load unit.

[0014] To identify when the capacity limit of the clock-controlled power supply unit has been reached, it is beneficial for the control unit to monitor the sum of current measurements of the output voltage of the clock-controlled power supply unit or the current consumed by the respective load circuits. In the simplest case, the output voltage of the clock-controlled power supply unit (i.e., the supply voltage) is used as a criterion by the control unit. Here, it is monitored whether the output voltage of the clock-controlled power supply unit has reached or exceeded a predetermined limit value (e.g., 20 V). Alternatively, (given the known characteristics of the power supply unit) multiple voltage limit values ​​can be predetermined, each corresponding to a different current information regarding the overload state of the power supply unit. The voltage limit values ​​can be evaluated step-by-step or compared with the current output voltage of the power supply unit, and the corresponding current degree of overload and corresponding measures (e.g., reducing and / or shutting off the current in individual load circuits, multiple load circuits, etc.) can be derived from this.

[0015] Alternatively, the control unit can calculate the current sum from the current value consumed by the load circuit and use this sum as a criterion. The control unit then checks whether the corresponding sum has reached and / or exceeded a predetermined limit. The predetermined limit for the output voltage or for the current sum of current consumed in the load circuit is ideally derived from the overload capacity of the power supply unit.

[0016] Ideally, a time interval can be predetermined during which the capacity limit of the clock-controlled power supply unit can be exceeded by a predetermined level. That is, the power supply unit can provide a predetermined overcurrent as output current for a short, predetermined duration (e.g., 5 ms), exceeding the normally supplied continuous current. This overload capability can be used to cover dynamic current behavior processes in the device (e.g., the parallel switching of multiple load circuits).

[0017] A suitable improvement specifies that, in order to identify the reaching of the capacity limit of the clock-controlled power supply unit, the current load value or the reaching and / or exceeding of the power limit is continuously transmitted from the clock-controlled power supply unit to the control unit. The power supply unit can, for example, detect internal thermal conditions (e.g., temperature, degree of heating, etc.), input voltage fluctuations (e.g., voltage peaks, grid faults, phase loss, etc.), and calculate, for example, parameters related to the current condition, which reproduce the current capacity of the clock-controlled power supply unit. These parameters are forwarded to the control unit as current load values ​​and can be used by the control unit to monitor the capacity limit of the power supply unit. This advantageously considers the current condition of the power supply unit, such as heating, faults in the input voltage, etc. Furthermore, based on the current load value, it can be pre-calculated when the power supply unit must, for example, reduce the output voltage for self-protection, or when at least the capacity limit is reached.

[0018] Ideally, the control unit predefines the order in which current is reduced and / or switched off in those load circuits that exceed the upper limit of the tolerance range of the significant current distribution pattern allocated to the respective load circuits. For example, it can be specified that the current consumed in those load circuits that most strongly load or consume the most current to the power supply unit NG is reduced and / or switched off first. This allows for a simple and rapid unloading of the power supply unit.

[0019] Furthermore, the control unit advantageously assigns status flags to those load circuits whose current variation, currently measured for the corresponding load circuit, exceeds the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit during continuous operation of the device. This clearly indicates load circuits exceeding tolerances, which consume current exceeding common limits during continuous operation of the device. If, for example, the power demand of a load circuit decreases, i.e., the currently measured current variation of that load circuit again extends within the tolerance range of the significant current distribution map assigned to the corresponding load circuit, it can be specified, for example, that the status flag of that load circuit be reset again.

[0020] Therefore, it is beneficial for the control unit to use the status flags currently assigned to the corresponding load circuits when the capacity limit of the clock-controlled power supply unit is reached and / or exceeded. This allows for the simple and quick identification of those load circuits that should perform current reduction and / or current shutdown in the event of a supply shortage or emergency.

[0021] Furthermore, ideally, based on the currently measured current changes in the load circuits monitored by the control unit during continuous operation of the equipment, alarm messages can be output for those load circuits where the current changes currently measured for the corresponding load circuit exceed the upper limit of the tolerance range of the significant current profile assigned to the corresponding load circuit during continuous operation of the equipment. For example, the alarm message can be logged or forwarded to the operator of the equipment, and ideally, a description of the "obvious" current behavior in the load circuits of the equipment can be provided. Furthermore, the alarm message can be weighted according to system hazards, for example. For this purpose, for example, it can be evaluated whether the current consumed in the load circuit exceeds the tolerance range of the corresponding significant current profile only slightly and / or briefly, or whether there is a larger and / or longer-lasting exceedance of the tolerance range of the corresponding current profile.

[0022] A suitable design of the present invention specifies that, in order to reduce the current consumed by the corresponding load circuit, the control unit operates the switching unit of the corresponding load circuit such that the current consumed by the corresponding load circuit is limited in time. That is, in the event of a supply shortage or emergency, the switching unit protecting the corresponding load circuit is linearly controlled to maintain the current in the corresponding load circuit at a predetermined value, regardless of the behavior of at least one load unit or nominal load arranged in the load circuit. Alternatively, to reduce the current consumed in the corresponding load circuit, the control unit can also operate the switching unit of the corresponding load circuit to switch the switching unit to clock operation. That is, in this case, the switching unit is pulsed by the control unit to maintain the current in the corresponding load circuit at a predetermined value. In the simplest case, the current consumed by the corresponding load circuit is completely cut off, for example, after a predetermined time, wherein the switching unit protecting the load circuit is operated accordingly.

[0023] Furthermore, it is beneficial if the significant current distribution of the corresponding load circuit is derived during the learning phase from the current variation process (Stromverlauf) measured for the corresponding load circuit based on preset data. This preset data ideally includes typical and characteristic current patterns of load cells frequently used in the load circuit. Such current patterns are, for example, the shape of the current variation process characteristic of each load cell. Here, the preset data may include the following exemplary current patterns: for example, a typical pure ohmic distribution for simple sensors, heating elements, etc.; a capacitive current-limiting distribution with a current peak that decays according to an exponential function, and this capacitive current-limiting distribution may be typical for, for example, sensor cells; an inductive ohmic distribution with a delta, typical for, for, solenoid valves, contactors, etc.; a distribution with a current rise, followed by a waiting time and a renewed current rise, for example, a distribution typically present in control devices during startup; and so on. Characteristic current patterns are determined, for example, based on historical current variation processes, on their own computer unit (e.g., PC), and are given as preset data for the control unit, for example, before the learning phase, ideally before the device is first put into operation, so as to more quickly derive the significant current distribution map of the load circuit of the device control unit.

[0024] Ideally, a trained neural network is used to derive the salient current distribution map of the corresponding load circuit. Using a trained neural network significantly accelerates the derivation of the corresponding salient current distribution map of the device's load circuit. For example, the neural network can be trained on its own computer unit (e.g., a PC) using training data such as typical and characteristic current patterns of load cells frequently used in load circuits. Through training, the neural network accumulates weighted decision criteria that allow it to quickly distinguish between different current patterns and rapidly identify recurring current patterns during measured current changes in the load circuit. The trained neural network is then transferred to the control unit, ideally before the device is first put into operation, after appropriate training and before the learning phase, where the learning phase can significantly accelerate the finding of the salient current distribution map for the corresponding load circuit and the determination of the respective tolerance ranges—that is, the recurring current patterns plus corresponding fluctuation regions in terms of current level, duration, and shape of the change process.

[0025] A preferred embodiment of the invention specifies that a minimum duration is pre-defined for the learning phase, during which a significant current distribution map for the corresponding load circuit is derived from current changes measured for that load circuit. The minimum duration of the learning phase ensures that at least two typical iterative current patterns are found for each load circuit during current changes measured for that load circuit, such that a significant current distribution map and at least one coarse tolerance range for that current distribution map can be defined based on at least two typical iterative current patterns.

[0026] In the most extreme cases, the learning phase can encompass the entire lifespan of the equipment. That is, even during continuous operation, the current variation measured against the load circuit is examined against typical current patterns to continuously refine and improve the assigned significant current profile and the corresponding tolerance range of the load circuit. Furthermore, changes in the significant current profile (e.g., in terms of level, duration, and / or shape of the variation process) can indicate aging or impending malfunction of the load cells within the corresponding load circuit. Such changes can be readily identified by the control unit.

[0027] Thus, for example, the current variation measured for the affected load circuit during equipment operation may persistently exceed or not exceed the tolerance range of the significant current distribution diagram assigned to the load circuit. For example, the affected load circuit may be reported to the equipment operator, for example, by means of an alarm message. Prior to the alarm message, a correlation test may still be performed, where deviations from the significant current distribution diagram or exceedances or not exceedances of the assigned tolerance range are reported only if there is a pre-given minimum deviation from, for example, the current level and / or shape of the variation process in the significant current distribution diagram.

[0028] Furthermore, provided pre-defined criteria are met, repeated deviations from the significant current distribution diagram or repeated exceedances or non-exceedances of the corresponding tolerance range may lead to a corresponding adaptation of the significant current distribution diagram or the corresponding tolerance range of the load circuit. One possible criterion is, for example, the regular or uniform occurrence of deviations from the current distribution diagram or repeated exceedances or non-exceedances of the corresponding tolerance range. It can thus be assumed, for example, that these correspond to "normal" current variation processes in the affected load circuit. For example, the significant current distribution diagram or the corresponding tolerance range of the affected load circuit can be automatically adapted. However, it can also be stipulated that the operator of the equipment must verify this adaptation. The operator can, for example, confirm beforehand that no obvious defects or abnormal operating behavior have occurred in the affected load circuit.

[0029] Since at least several load circuits in the control device are protected by switching units, and these switching units function as electronic fuses, ideally a safety limit value is pre-defined for each load circuit protected by the switching unit. When this safety limit value is reached or exceeded, the current consumed by the corresponding load circuit is always cut off. This safety limit value is the maximum value of the load circuit current, and ideally, it should be placed above the upper limit of the tolerance range of the significant current distribution diagram assigned to the corresponding load circuit. The safety limit is set to meet fire protection requirements and, in the worst-case scenario, prevent fire in the event of a defective load unit in the load circuit.

[0030] Furthermore, it is advantageous to install additional protective devices, for example, to meet fire protection requirements. Here, other protective devices (e.g., circuit breakers, fuses, etc.) are connected upstream of the switching unit protecting the corresponding load circuit, and these other protective devices are triggered under any circumstances, for example, in the event of a switch unit failure. For this purpose, protective devices can be selected such that only at least one load unit in the protected circuit and load circuit is protected from the current level or current change process of damage and / or fire.

[0031] One advantageous embodiment of the present invention specifies that a power transistor or microelectromechanical device, abbreviated as MEMS, is used as a switching unit. Power transistors and MEMS represent electronic switches that can be very easily controlled by a control unit to limit current. Furthermore, the current can be very easily interrupted by the power transistor or MEMS acting as a switching unit. MEMS are typically miniature semiconductor devices that ideally integrate logic elements and micromechanical structures (e.g., armatures that move via electrostatic forces) into a single device. Attached Figure Description

[0032] The invention is described below by way of example with reference to the accompanying drawings. Wherein:

[0033] Figure 1 Schematic and exemplary apparatus are shown for performing a method for monitoring and controlling current distribution in a load circuit of a technical device according to the present invention;

[0034] Figure 2 An exemplary flow diagram of a method for monitoring and controlling current distribution in a load circuit of a technical device according to the present invention is shown. Detailed Implementation

[0035] Figure 1An exemplary device SV for supplying power to a device control unit in a technical apparatus is illustrated schematically. Using the exemplary device SV, the current distribution in the load circuits L1, L2, and L3 of the device control unit can be monitored and controlled. For this purpose, the device SV has a clock-controlled power supply unit NG, such as a switching power supply section, which is powered by the mains voltage U. N (For example, DC voltage, single-phase or three-phase AC voltage) is fed. The clock-controlled power supply unit NG is connected to a reference potential BP (e.g., 0 volts) and provides an output voltage U with a regulated and mostly pre-defined value (e.g., 24 volts). A and output current I A Furthermore, the current load value (Auslastungswerte) AW can be continuously transmitted from the power supply unit NG (as long as the power supply unit is set for this purpose) to the control unit SE.

[0036] In addition, at least one load circuit L1, L2, L3 is provided for the equipment control device. However, the equipment control device usually has multiple load circuits L1, L2, L3. Each load circuit L1, L2, L3 has at least one load unit, such as a sensor, actuator, relay, contactor, solenoid valve, drive unit for motor, servo motor, control device, display unit, etc. On one hand, the load circuits L1, L2, L3 are also connected to a reference potential. On the other hand, the load circuits L1, L2, L3 are connected to a clock-controlled power supply unit NG via branches A1, A2, A3 to supply power to the load units. For this purpose, the output voltage U provided by the power supply unit NG... A Or output current I A They are assigned to the corresponding load circuits L1, L2, and L3.

[0037] Furthermore, at least several of the load circuits L1, L2, and L3 are protected by switching units S1, S2, and S3. That is, individual load circuits L1, L2, and L3 that require very low current and / or must be supplied almost always (e.g., load circuits L1, L2, and L3 with control devices as load units) may not have switching units S1, S2, and S3 for protection. Ideally, all load circuits L1, L2, and L3 are protected using switching units S1, S2, and S3, such as... Figure 1 As exemplified in the example, the switching units S1, S2, and S3 function as electronic and configurable safety devices for the corresponding load circuits L1, L2, and L3. For this purpose, each switching unit S1, S2, and S3 is controlled by corresponding control signals AS1, AS2, and AS3 from the control unit SE. Thus, the current consumed by the corresponding load circuits L1, L2, and L3, and consequently the output current I of the power supply unit NG, can be controlled accordingly.A The distribution to the load circuits L1, L2, and L3. For example, power transistors or microelectromechanical systems (MEMS) can be used as switching units S1, S2, and S3. Additionally, other protective devices (e.g., line protection switches, fuses, etc.) can be provided, for example, connected upstream of the respective switching units S1, S2, and S3. For simplicity, in Figure 1 Additional protective devices are not shown.

[0038] In addition, measurement units ME1, ME2, and ME3 are installed in branches A1, A2, and A3 of the corresponding load circuits L1, L2, and L3. The measurement units ME1, ME2, and ME3 measure the current changes i1, i2, and i3 of the current consumed by the corresponding load circuits L1, L2, and L3 and forward the data to the control unit SE for corresponding monitoring and evaluation.

[0039] The control unit SE, which operates the switching units S1, S2, S3 by means of control signals AS1, AS2, AS3 and monitors the current changes i1, i2, i3 in the load circuits L1, L2, L3, can be, for example, a microprocessor.

[0040] In addition, the control unit SE may have at least one storage unit SP, such as the output voltage U of the power supply unit. A The limit values ​​to be monitored, the limit values ​​of the sum of currents in load circuits L1, L2, and L3, and / or the settable values ​​for switching units S1, S2, and S3 are stored in the storage unit. Additionally, a pre-defined safety limit value can be stored, for example, for each switching unit SE, in the storage unit SP of the control unit SE. At this pre-defined safety limit value (e.g., the maximum permissible load circuit current), the current consumed by the corresponding load circuits L1, L2, and L3 is interrupted by the corresponding switching units S1, S2, and S3 in any case. Furthermore, preset data VD (e.g., current patterns, decision criteria for neural networks, etc.) can be stored in the storage unit SP. This preset data is determined, for example, on an external computer unit PC and is required when implementing methods for monitoring and controlling the current distribution in load circuits L1, L2, and L3.

[0041] To distribute the load units of the device control unit to the load circuits L1, L2, L3, for example, the clock-controlled power supply unit NG itself may have at least one or more output terminals A1, A2, A3, and the load circuits L1, L2, L3 are directly connected to said output terminals. Here, each output terminal A1, A2, A3 is protected by switching units S1, S2, S3, and has measuring units ME1, ME2, ME3 for measuring the current changes i1, i2, i3 in the connected load circuits L1, L2, L3. Furthermore, the control unit SE is integrated into the power supply unit NG. That is, the power supply unit includes components from... Figure 1 The unit surrounded by dashed lines, and therefore corresponds to Figure 1 The device SV is shown as an example in the diagram.

[0042] Alternatively, at least one or more electronic fuse modules, such as Siemens' selective modules SITOP SEL1200 or SITOP SEL1400, can be connected downstream of the clock-controlled power supply unit NG. The corresponding fuse module then has output terminals A1, A2, A3, to which load circuits L1, L2, L3 are connected. Here, the fuse module includes switching units S1, S2, S3 for protecting output terminals A1, A2, A3 or the connected load circuits L1, L2, L3; measuring units ME1, ME2, ME3 for measuring current changes i1, i2, i3 in the connected load circuits L1, L2, L3; and a control unit SE.

[0043] When using multiple fuse modules, the control unit SE can, for example, be divided into multiple functional units distributed across the respective fuse modules. At least one functional unit of the fuse module or control unit SE, arranged on the fuse module, is connected, for example, via a data bus. One of the distributed functional units is a so-called master functional unit for controlling or monitoring load circuits L1, L2, L3 in a superior manner, and other distributed functional units function as so-called slave functional units for locally and quickly controlling or monitoring load circuits L1, L2, L3 connected to the respective fuse modules. Furthermore, for the functional units of the control unit SE, a storage unit SP can be provided in each fuse module, where at least locally, those values ​​necessary for controlling and monitoring the current in the load circuits L1, L2, L3 connected to the respective fuse modules (e.g., fuse limit values) are stored.

[0044] Figure 2Exemplary illustrations of monitoring and control according to the present invention, such as in... Figure 1 The flowchart illustrates the method for current distribution in the load circuits L1, L2, and L3 of the device control unit in the technical equipment shown.

[0045] In a learning phase, which may begin with the initial operation of the equipment, in measurement step 101, the current change processes i1, i2, i3 of the current consumed by each load circuit L1, L2, L3 protected by the switching units S1, S2, S3 are measured. For example, the measurements can be performed using measurement units ME1, ME2, ME3 provided for the respective load circuits. The current change processes i1, i2, i3 measured for the respective load circuits L1, L2, L3 are then forwarded to the control unit SE.

[0046] In derivation step 102, which is also part of the learning phase, significant current profiles with corresponding tolerance ranges are derived from the current change processes i1, i2, i3 measured for the respective load circuits L1, L2, L3. To this end, recurring characteristic current patterns are searched for in the current change processes i1, i2, i3 measured for the respective load circuits L1, L2, L3. These current patterns represent segments of the separately measured current change processes i1, i2, i3, which have nearly identical current levels, durations, and / or change process shapes. Specifically, the current pattern should contain the highest instantaneous current value.

[0047] Then, significant current distribution maps for the corresponding load circuits L1, L2, L3 are derived from the recurring current patterns found for those load circuits L1, L2, L3. These current distribution maps ideally represent the static and dynamic current behaviors (on-off behavior) of the corresponding load circuits L1, L2, L3 during continuous operation of the device or device control unit. Furthermore, in derivation step 102, tolerance ranges belonging to the significant current distribution maps are determined from the recurring current patterns found for the corresponding load circuits L1, L2, L3. The corresponding tolerance ranges are derived from drifts in, for example, current level, duration, and / or shape of the change process of the recurring current patterns found in the corresponding current change processes i1, i2, i3 for the corresponding load circuits L1, L2, L3. Safety reserves can be added to the corresponding tolerance ranges if necessary.

[0048] To identify characteristic current patterns in the corresponding current change processes i1, i2, i3, preset data VD, such as current patterns frequently occurring in load circuits and / or typical current patterns for frequently used load units, can be used in derivation step 102. Ideally, the preset data VD is determined in advance, for example, on an external computer unit PC based on the historical current change processes of load circuits L1, L2, L3, and / or individual load units, and is transmitted to the control unit SE, for example, before the learning phase, and stored there in the storage unit SP.

[0049] To accelerate the identification of current patterns in the corresponding current change processes i1, i2, i3, or to derive the significant current distribution diagrams and respective tolerance ranges of the corresponding load circuits L1, L2, L3 from the measured current change processes i1, i2, i3, a trained neural network can be used in derivation step 102. Prior to the learning phase, the neural network has been trained on an external computer unit PC using training data, such as typical and characteristic current patterns of load cells frequently used in load circuits L1, L2, L3, and then transmitted to the control unit SE.

[0050] For example, a minimum duration can be set for the learning phase, which includes at least measurement step 101 and derivation step 102. Within this minimum duration, at least two characteristic current patterns for the corresponding load circuits L1, L2, L3 should be found in each measured current change process i1, i2, i3, so that at least one significant current distribution map with a rough tolerance range can be derived for the corresponding load circuits L1, L2, L3. After the predetermined minimum duration of the learning phase, the device can, for example, continue to operate. However, in the maximum case, the learning phase can last for the entire lifespan of the device. Here, the significant current distribution maps and their respective tolerance ranges for the load circuits L1, L2, L3 can be adapted and improved even during continuous operation. Here, for example, a slight exceedance and / or non-exceedance of the tolerance range of the current distribution map may lead to adaptation of the corresponding significant current distribution map. Larger or greater exceedances and / or non-exceedances within the tolerance range can be evaluated as errors in the corresponding load circuits L1, L2, L3, and, for example, trigger alarms or messages to the operator of the equipment, wherein the exceedances and / or non-exceedances are determined, for example, based on a pre-given percentage value of the exceedance and / or non-exceedance.

[0051] During continuous operation of the equipment, the control unit SE continuously monitors the current changes i1, i2, i3 currently measured by the corresponding measurement units ME1, ME2, ME3 for each load circuit L1, L2, L3 in monitoring step 103. Here, the control unit SE can, for example, check whether the current changes i1, i2, i3 currently measured for the corresponding load circuit L1, L2, L3 exceed the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit L1, L2, L3. If such an exceedance is determined, a status flag can be assigned to the corresponding load circuit L1, L2, L3, which, for example, remains in place until the control unit SE determines that the current changes i1, i2, i3 currently measured for the corresponding load circuit L1, L2, L3 are again within the tolerance range of the significant current distribution map assigned to the corresponding load circuit L1, L2, L3. Alternatively or additionally, the control unit SE may output an alarm message for each load circuit L1, L2, L3, wherein the current change processes i1, i2, i3 currently measured for the corresponding load circuit L1, L2, L3 exceed the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit L1, L2, L3.

[0052] Furthermore, in the inspection step 104, which operates more or less in parallel with the monitoring step 103, the control unit SE inspects whether the clock-controlled power supply unit NG has reached or exceeded its capacity limit. To identify, for example, whether the power supply unit NG has reached or may have exceeded its capacity limit in inspection step 104, the control unit may monitor the output voltage U of the power supply unit NG. A If the output voltage U of the power supply unit NG A If the predetermined limit value has not been exceeded, then the power supply unit NG has at least reached its capacity limit. That is, under the current load caused by the load circuits L1, L2, and L3, the power supply unit NG can no longer maintain its predetermined output voltage U. A And the control unit SE begins in control step 105 to at least reduce and / or shut off the current consumed in the load circuits L1, L2, L3.

[0053] The output voltage U of the power supply unit NG AAlternatively, the control unit SE can monitor the sum of the current measurements of the current consumed by the load circuits L1, L2, and L3. To do this, the control unit SE, for example, evaluates the current changes i1, i2, and i3 of the load circuits L1, L2, and L3 measured by the measurement units ME1, ME2, and ME3, and determines the current sum of the corresponding current measurements. This sum is then compared to a predetermined limit (e.g., the known power reserve of the power supply unit NG). If the sum exceeds the predetermined limit, the control unit SE identifies that the power supply unit NG has at least reached its capacity limit and begins to at least reduce and / or shut off the current consumed in the load circuits L1, L2, and L3 in control step 105.

[0054] However, a short time interval (e.g., 5 ms) can be predetermined, during which the power supply unit NG can at least slightly exceed its capacity limit. Thus, the power supply unit NG briefly provides an overcurrent as the output current I. A The overcurrent exceeds the output current I that is normally provided as a continuous current. A However, if the predetermined time interval is exceeded, the capacity limit of the power supply unit NG is at least reached, and the control unit SE must, starting from control step 105, at least reduce and / or shut off the current consumed in the load circuits L1, L2, and L3.

[0055] Alternatively, the control unit SE can deduce from the current distribution diagrams individually allocated to the load circuits L1, L2, L3 how long the overcurrent (e.g., the switching current) will last before the control unit SE begins to reduce the current in one or more load circuits L1, L2, L3 in control step 105. The control unit SE can compare the additional current consumption derived therefrom with the time-limited overcurrent capability of the power supply unit NG. If the comparison shows that the power supply unit NG can provide the necessary overcurrent for the expected duration (i.e., only slightly exceeding the power limit), then, for example, the supply to the load circuits L1, L2, L3 is not intervened for the time being. For example, the current in the load circuits L1, L2, L3 is reduced and / or turned off only when a non-compliance with the significant current distribution diagram can be identified.

[0056] Furthermore, the power supply unit NG can continuously transmit the current load value AW to the control unit SE, which, for example, reproduces the current status of the power supply unit NG in the form of parameters, such as internal thermal conditions (e.g., temperature, degree of heating), input voltage fluctuations (e.g., voltage peaks, grid faults, phase loss, etc.). Based on the current load value AW of the power supply unit NG, the control unit SE can identify the current capacity of the power supply unit NG and, for example, pre-calculate when and whether the power supply unit NG must, for example, reduce its output voltage U for self-protection. A If the power supply unit NG reaches or exceeds its capacity limit, the control unit SE begins in control step 105 to at least reduce and / or shut off the current consumed in those load circuits L1, L2, L3 where the current changes i1, i2, i3 currently measured for the respective load circuits L1, L2, L3 exceed the upper limit of the tolerance range of the significant current distribution map allocated to the respective load circuits L1, L2, L3. Here, the control unit SE uses control signals AS1, AS2, AS3 to manipulate the corresponding switching units S1, S2, S3 of these load circuits L1, L2, L3 to reduce and / or shut off the current in the respective load circuits L1, L2, L3.

[0057] To reduce the current consumed by the corresponding load circuits L1, L2, and L3, the corresponding switching units S1, S2, and S3 can be controlled by corresponding control signals AS1, AS2, and AS3, thereby limiting the current consumed by the corresponding load circuits (L1, L2, and L3) over time. However, the switching units S1, S2, and S3 can be clocked by the corresponding control signals AS1, AS2, and AS3, and maintained at a constant value, for example, through clock operation. If reducing the current in load circuits L1, L2, L3 that exceed the tolerance (i.e., load circuits L1, L2, L3 where the current changes i1, i2, i3 exceed the upper limit of the tolerance range of the significant current distribution diagram allocated to the corresponding load circuits L1, L2, L3) cannot achieve the capacity limit of the power supply unit NG, then one or all load circuits L1, L2, L3 that exceed the tolerance can also be turned off by the corresponding operating signals AS1, AS2, AS3 from the control unit SE to the corresponding switching units S1, S2, S3.

[0058] To quickly identify load circuits L1, L2, and L3 that exceed tolerances, the control unit SE can utilize status flags from monitoring step 103 in control step 105. Status flags have already been assigned in monitoring step 103 to those load circuits L1, L2, and L3 whose current changes i1, i2, and i3 currently measured in monitoring step 103 exceed the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuits L1, L2, and L3.

[0059] In control step 105, the control unit SE can be given a pre-defined sequence in which the current in load circuits L1, L2, L3 exceeding the tolerance is reduced, or the load circuits L1, L2, L3 exceeding the tolerance are turned off, according to the pre-defined sequence. In the case of this pre-defined sequence, for example, it can be specified that the current reduction and / or current shutdown are first performed in those load circuits L1, L2, L3 that most strongly exceed the corresponding upper limit of the tolerance range of their respective assigned significant current distribution diagrams. This means that the current in those load circuits L1, L2, L3 that most strongly load the power supply unit NG, consume the most current, or are most likely to be defective, exceeding the tolerance, is reduced and / or shut off first.

[0060] Furthermore, if, for example, the current reduction and / or current shutdown in a load circuit exceeding the tolerance is insufficient to restore the capacity of the power supply unit NG, there is an additional possibility that the current consumed by the corresponding load circuits L1, L2, and L3 may also be reduced and / or shut off in other (non-tolerance) load circuits L1, L2, and L3. Here, the current consumed in the load circuits L1, L2, and L3 may be shut off, for example, according to a pre-defined priority of the load circuits, so as to supply as much energy as possible to important load circuits L1, L2, and L3 or important load units (e.g., control devices) connected to them and keep them available for an extended period.

Claims

1. A method for monitoring and controlling the current distribution in the load circuit (L1, L2, L3) of a device control unit for technical equipment, wherein a predetermined output voltage (U) is provided by at least one clock-controlled power supply unit (NG). A The output voltage is distributed to the load circuits (L1, L2, L3) for power supply, and at least a plurality of the load circuits (L1, L2, L3) are protected by switching units (S1, S2, S3) controlled by a control unit (SE). During the learning phase, at least in the load circuits (L1, L2, L3) protected by the switching units (S1, S2, S3), the current changes (i1, i2, i3) consumed by the respective load circuits (L1, L2, L3) are measured (101). From the current changes (i1, i2, i3) measured for the respective load circuits (L1, L2, L3), at least one significant current distribution map and its corresponding tolerance range are derived and assigned to the respective load circuits (L1, L2, L3) (102). During continuous operation of the device, the control unit (SE) continuously monitors at least the currently measured current in the load circuits (L1, L2, L3) protected by the switching units (S1, S2, S3). The current change process (i1, i2, i3) (103) and the check (104) whether the clock-controlled power supply unit (NG) has at least reached the capacity limit, and when the clock-controlled power supply unit (NG) has at least reached the capacity limit, the control unit (SE) at least reduces and / or shuts off the current consumed by the corresponding load circuit (L1, L2, L3) by manipulating the corresponding switching units (S1, S2, S3) in those load circuits (L1, L2, L3) in which the current change process (i1, i2, i3) currently measured for the corresponding load circuit (L1, L2, L3) exceeds the upper limit of the tolerance range of the current distribution diagram allocated to the corresponding load circuit (L1, L2, L3).

2. The method according to claim 1, characterized in that, In order to identify the attainment of the capacity limit of the clock-controlled power supply unit (NG), the control unit (SE) monitors the sum of the current measurements of the output voltage (UA) of the clock-controlled power supply unit (NG) or the current consumed by the load circuits (L1, L2, L3) respectively (104).

3. The method according to claim 1 or 2, characterized in that, A predetermined time interval is given during which the capacity limit of the clock-controlled power supply unit (NG) can be exceeded by a predetermined level.

4. The method according to claim 1 or 2, characterized in that, In order to identify the attainment of the capacity limit of the clock-controlled power supply unit (NG), the current load value (AW) or the attainment and / or exceeding of the capacity limit is continuously transmitted from the clock-controlled power supply unit (NG) to the control unit (SE) (104).

5. The method according to claim 1 or 2, characterized in that, The control unit (SE) is pre-defined to reduce and / or shut off the current in those load circuits (L1, L2, L3) where the current change process (i1, i2, i3) currently measured for the corresponding load circuit exceeds the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit (L1, L2, L3).

6. The method according to claim 1 or 2, characterized in that, A status flag is assigned to those load circuits (L1, L2, L3) in which the current change process (i1, i2, i3) currently measured for the corresponding load circuit (L1, L2, L3) exceeds the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit (L1, L2, L3) during the continuous operation of the device (103).

7. The method according to claim 6, characterized in that, When the capacity limit is reached by the clock-controlled power supply unit (NG), the control unit (SE) uses the status flag (105) currently assigned to the corresponding load circuit (L1, L2, L3).

8. The method according to claim 1 or 2, characterized in that, For those load circuits (L1, L2, L3) whose current change process (i1, i2, i3) currently measured for the corresponding load circuit (L1, L2, L3) exceeds the upper limit of the tolerance range of the significant current distribution map assigned to the corresponding load circuit (L1, L2, L3) during continuous operation of the device, an alarm message (103) is output.

9. The method according to claim 1 or 2, characterized in that, In order to reduce the current consumed by the respective load circuits (L1, L2, L3), the switching units (S1, S2, S3) of the respective load circuits (L1, L2, L3) are controlled by the control unit (SE) (105) so that the current consumed by the respective load circuits (L1, L2, L3) is limited in time and / or the switching units (S1, S2, S3) are switched to clock operation.

10. The method according to claim 1 or 2, characterized in that, The significant current distribution diagram of the corresponding load circuit (L1, L2, L3) is derived from the current change process (i1, i2, i3) measured for the corresponding load circuit (L1, L2, L3) based on preset data (VD) (102).

11. The method according to claim 1 or 2, characterized in that, The trained neural network was used to derive the significant current distribution diagrams (102) of the corresponding load circuits (L1, L2, L3).

12. The method according to claim 1 or 2, characterized in that, A minimum duration is pre-defined for the learning phase.

13. The method according to claim 1 or 2, characterized in that, Furthermore, a safety limit is pre-defined for each load circuit (L1, L2, L3) protected by the switching unit. When the safety limit is reached and / or exceeded, the current consumed by the corresponding load circuit (L1, L2, L3) is always turned off.

14. The method according to claim 1 or 2, characterized in that, Additional protection devices are provided in the load circuits (L1, L2, L3).

15. The method according to claim 1 or 2, characterized in that, Power transistors or microelectromechanical systems, or MEMS for short, are used as switching units (S1, S2, S3).

Images