Method, circuit arrangement and interposer for correlating current values

Abstract

The invention relates to a method for associating current values (i) in a multi-phase load circuit (L) with corresponding voltage values (u), in which electrical energy is transmitted from a voltage source (100) to an electric machine (M), and in which commutation contactor circuits (WS, Q1, Q2) connected into the load circuit enable a change in the direction of rotation (RotR, RotL) of the electric machine by means of two different phase conductor arrangements (LR, LL), the invention relates to a method for detecting a current value in a phase conductor (L1, L2, L3) of a load circuit downstream of a commutation contactor circuit as viewed in the direction of the power transmission, detecting a voltage value in the load circuit upstream of the commutation contactor circuit by measuring at least one voltage in the load circuit as viewed in the direction of the power transmission, and detecting the current value in the phase conductor (L1, L2, L3) of the load circuit upstream of the commutation contactor circuit as viewed in the direction of the power transmission. -providing information about the phase conductor arrangement (LR, LL) present at the time at which the current and voltage values are detected; associating the detected current value with the corresponding detected voltage value on the basis of the provided information.

Description

Technical Field

[0001] The invention relates to a method for associating current values ​​with corresponding voltage values, a corresponding circuit arrangement, and an insert for a motor control center. Background Art

[0002] Continuously monitoring the active power of electrical consumers, such as electric motors, provides valuable information to their operators. The active power of a motor indicates its actual load. Excessive active power can lead to increased wear and tear, potentially leading to premature failure. Excessive active power can be a sign of motor idling. For example, by monitoring the temporal behavior of a pump drive's active power, impending dry-running can be detected at an early stage. If the power consumption falls below the minimum, the pump drive can be shut down promptly to prevent potentially serious subsequent damage.

[0003] In order to correctly detect the active power in a three-phase system having three phases L1, L2, L3, the current signal i and the voltage signal u of each of the three phases L1, L2, L3 must be evaluated in a correctly correlated manner. Current and voltage detection modules are typically used to detect the current and voltage signals.

[0004] Using a reversing contactor circuit (left-hand or right-hand rotation), the direction of rotation of a three-phase motor can be reversed by interchanging two phase conductors. Due to the two different phase conductor arrangements, special attention must be paid to the correct correlation of the current signal i and the voltage signal u for the three phases L1, L2, and L3 in the reversing contactor circuit.

[0005] One possibility is to perform current and voltage sensing upstream of the reversing contactor, i.e., upstream of the point where the phase conductors are interchanged, as viewed in the direction of power transmission to the consumer. Upstream of the reversing contactor, corresponding current and voltage values ​​must always be measured on the same phase conductor. However, in many cases, current and voltage sensing upstream of the reversing contactor is not possible for space reasons. For example, in the insert (withdrawable unit or drawer) of a motor control center (MCC), there is insufficient installation space for the current and voltage sensing modules.

[0006] Another option is to perform current and voltage measurements downstream of the reversing contactor, i.e., downstream of the reversing point, as viewed in the direction of power transmission to the consumer. Corresponding current and voltage values ​​must always be measured on the same phase conductor downstream of the reversing contactor. However, in this circuit arrangement, when the motor is off (both reversing contactors are closed), it is not possible to use voltage measurement to check whether voltage is present in the current path upstream of the reversing contactor. This arrangement makes it impossible to implement monitoring functions that require voltage detection, such as automatic restart after a power outage. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an improved circuit arrangement which enables active power detection and voltage monitoring in a reversing contactor circuit.

[0008] According to the present invention, the above-mentioned technical problem is solved by a method having the features according to the present invention. The method is a method for associating current values ​​in a multi-phase load circuit with corresponding voltage values. In the multi-phase load circuit, electrical energy is transmitted from a voltage source to a motor. Since the present invention belongs to the field of electrical engineering, the motor herein is always understood to be an electric motor. In the multi-phase load circuit, a reversing contactor circuit connected to the load circuit can achieve a change in the direction of rotation of the motor using two different phase conductor arrangements. The method includes the steps of detecting the current value in the phase conductors of the load circuit. The current value is detected downstream of the reversing contactor circuit, as viewed in the direction of electrical energy transmission. The method includes the steps of detecting the voltage value in the load circuit by measuring at least one voltage in the load circuit. The voltage value is detected upstream of the reversing contactor circuit, as viewed in the direction of electrical energy transmission. The voltage in the phase conductors of the load circuit can be detected by measuring the potential of the phase conductor relative to another potential (e.g., the potential of another phase conductor, the potential of a neutral conductor, ground potential, or another reference potential). The method includes the step of providing information about the phase conductor arrangement present at the time of detecting the current and voltage values. And the method has the step of associating the detected current values ​​with corresponding detected voltage values ​​based on the provided information.

[0009] The above technical problem is also solved by a circuit arrangement. The circuit arrangement includes a multiphase load circuit for transmitting electrical energy from a voltage source to a motor. The circuit arrangement includes a reversing contactor circuit connected to the load circuit, which can change the direction of rotation of the motor using two different phase conductor arrangements. The circuit arrangement includes a current and voltage measuring device for detecting current and voltage values ​​in the phase conductors of the load circuit and for associating the detected current values ​​with corresponding detected voltage values. The circuit arrangement includes a data memory for providing information about the phase conductor arrangements present at the time of detecting the current and voltage values. The circuit arrangement includes a voltage tapping device for tapping at least one voltage in the phase conductors of the load circuit. The circuit arrangement includes electrical lines for supplying the at least one tapped voltage to the current and voltage measuring device. In this circuit arrangement, the current and voltage measuring device performs current detection downstream of the reversing contactor circuit, as viewed in the direction of electrical energy transmission from the voltage source to the motor. In this circuit arrangement, the voltage tapping device performs voltage tapping upstream of the reversing contactor circuit, as viewed in the direction of electrical energy transmission from the voltage source to the motor.

[0010] The present invention provides a method for reliably associating current values ​​with corresponding voltage values ​​in a multiphase load circuit, wherein electrical energy is transmitted from a voltage source to a motor, and a reversing contactor circuit connected to the load circuit is capable of changing the direction of rotation of the motor by means of two different phase conductor arrangements. On the one hand, the present invention takes into account the condition that a voltage detection must be performed upstream of the reversing contactor, so that the presence of a voltage in the current path upstream of the reversing contactor can be checked using a voltage measurement. On the other hand, the present invention takes into account the condition that, since the voltage detection is performed upstream of the reversing contactor, a current detection must be performed downstream of the reversing contactor, since there is insufficient installation space upstream of the reversing contactor for a combined current and voltage detection. The present invention is based on the recognition that the risk of phase conductor confusion can be eliminated by providing information about the phase conductor arrangement present at the time of detecting the current and voltage values.

[0011] The present invention is based on the recognition that it is advantageous to perform voltage detection upstream of the reversing contactor: thus, the voltage measurement can be used to check whether a voltage is present in the current path upstream of the reversing contactor. The present invention is also based on the recognition that it is advantageous to perform current detection downstream of the reversing contactor: sufficient installation space is available there.

[0012] Advantageous embodiments and developments of the invention are described in the present invention. The method according to the invention can also be further developed according to the features of the device according to the invention, and vice versa.

[0013] According to a preferred embodiment of the method, the current values ​​in all phase conductors of the load circuit are detected. This is technically useful in a three-phase system with three phase conductors. Current measurement can be performed, for example, using current transformers, shunt measuring resistors, GMR sensors (GMR = Giant Magneto Resistance Effect), Rogowski coils, or Hall sensors.

[0014] According to a preferred embodiment of the method, the voltage value in the load circuit is detected by measuring the voltage in all phase conductors of the load circuit. This is technically useful in a three-phase system having three phase conductors. The voltage in a phase conductor of the load circuit can be detected by measuring the potential of the phase conductor relative to another potential (e.g., the potential of another phase conductor of the load circuit, the potential of the neutral conductor of the load circuit, ground potential, or another reference potential).

[0015] According to a preferred embodiment of the method, the information about the phase conductor arrangement present at the time of detecting the current and voltage values ​​is provided by a data memory of a computing and control device, which determines the phase conductor arrangement by controlling the reversing contactor circuit. This advantageously means that the computing and control device for controlling the reversing contactor circuit is itself the entity that determines which phase conductor arrangement is present at a given time; the computing and control device is therefore the primary source of this information. This advantageously provides a simple solution.

[0016] The computing and control device can transmit this information to the current and voltage measuring device. In other words, the computing and control device, which controls the contactors of the reversing contactor circuit, informs the current and voltage measuring device which contactor of the reversing contactor circuit is closed. The current and voltage measuring device can then perform measurements with the correct correlation between current and voltage values ​​without having to determine the actual phase sequence beforehand. This offers the advantage that, due to the presence of this information, the current and voltage measuring device can immediately operate with the correct phase sequence within the device after the contactors of the reversing contactor circuit are closed, without causing undesirable delays in the calculation of other electrical variables, such as active power.

[0017] According to a preferred embodiment of the method, the detected current and voltage values ​​are analyzed over time. Based on the analysis performed, information about the phase conductor arrangement present at the time the current and voltage values ​​were detected is extracted and temporarily stored in an information-providing data memory. It is possible that, in a first "clockwise" phase conductor arrangement, the voltages in the phase conductors reach their maximum values ​​in the order L1, L2, and L3, while in a second "counterclockwise" phase conductor arrangement, the voltages in the phase conductors reach their maximum values ​​in the order L3, L2, and L1. In this way, the temporal analysis of the voltages allows the phase conductor arrangement present at the time the current and voltage values ​​were measured to be determined and used to correctly correlate the current and voltage values. This approach has the advantage of being an elegant solution, even though it requires relatively high computing power. For example, it can be provided that the current and voltage measuring devices independently identify the correct correlation based on the voltage and current values ​​and independently perform this correlation.

[0018] According to a preferred embodiment of the method, the active power P of the motor is calculated based on the correlated current and voltage values: P=u·i. The advantage here is that this ensures a correct calculation of the active power of the motor.

[0019] According to a preferred embodiment of the circuit arrangement, the circuit arrangement includes a computing and control device for calculating the active power of the electric machine based on the correlated current and voltage values. This has the advantage that the computing and control device can provide a relatively high computing capacity. Based on the analysis of the voltage and current values, the computing and control device can extract information about the phase conductor arrangement present at the time the current and voltage values ​​were detected and temporarily store the extracted information in an information-providing data memory. The computing and control device can then transmit this information to the current and voltage measuring device.

[0020] According to a preferred embodiment of the circuit arrangement, the circuit arrangement includes a circuit breaker, which is connected to the load circuit upstream of the reversing contactor circuit, with respect to the transmission of electrical energy from the voltage source to the motor. The circuit breaker can be an MCCB (molded case circuit breaker). This has the advantage that the circuit breaker can protect the motor from faults (e.g., short circuits) in the load circuit.

[0021] According to a preferred embodiment of the circuit arrangement, the voltage tapping device directly taps the voltage on the circuit breaker. The advantage here is that the circuit breaker has connection terminals that can tap the voltage.

[0022] According to a preferred embodiment of the circuit arrangement, the current and voltage detection module has at least one through-current measuring transformer for detecting the current value, through which the individual phase conductors of the load circuit are passed. This has the advantage that the through-current measuring transformer enables robust, simple, and reliable current detection.

[0023] Another preferred embodiment of the present invention is an insert for a motor control center, which has the above-described circuit arrangement. The advantage here is that the circuit arrangement according to the present invention can make optimal use of the limited installation space of the insert. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is explained below using several exemplary embodiments with reference to the drawings.

[0025] The above-mentioned characteristics, features and advantages of the present invention and their implementation will be more clearly understood and appreciated through the following description of the embodiments explained in more detail with reference to the accompanying drawings, in which:

[0026] Figure 1 A first known circuit arrangement for associating current values ​​with corresponding voltage values ​​is shown;

[0027] Figure 2 The current and voltage measuring devices are shown;

[0028] Figure 3 An alternative known circuit arrangement for associating current values ​​with corresponding voltage values ​​is shown;

[0029] Figure 4 A first embodiment of a circuit arrangement is shown;

[0030] Figure 5 An alternative embodiment of a circuit arrangement is shown,

[0031] Figure 6 A flow chart showing the method; and

[0032] Figure 7 A motor control center is shown. DETAILED DESCRIPTION

[0033] Figure 1 A first known circuit arrangement for associating current values ​​with corresponding voltage values ​​is shown. This circuit arrangement has a multiphase load circuit L, in which electrical energy is transmitted from a voltage source 100 to a motor M. Motor M is a three-phase motor. In load circuit L, viewed in the direction from voltage source 100 to motor M, a circuit breaker CB, a current and voltage measuring device UM, and reversing contactor circuits WS, Q1, and Q2 are connected in the following order.

[0034] A circuit breaker CB, for example an MCCB (= Moulded Case Circuit Breaker), can interrupt the load circuit L in the event of a fault, such as a short circuit or overload, in order to prevent damage.

[0035] The current and voltage measuring device UM detects current values ​​and voltage values ​​in the load circuit L, and these current values ​​and voltage values ​​can be transmitted to the calculation and control device GG via a signal line 30 .

[0036] The load circuit L has a voltage source-side connection point 5 and a motor-side connection point 6, between which a reversing contactor circuit WS, Q1, Q2 is connected in the load circuit L. The reversing contactor circuits WS, Q1, Q2 enable a change in the direction of rotation RotR, RotL of the motor M. To reverse the direction of rotation, two contactors are required: a first contactor Q1 and a second contactor Q2, which interchange two phase conductors in the load circuit L. Activating the first contactor, "right contactor" (clockwise rotation, forward rotation), results in clockwise rotation RotR of the motor M; activating the second contactor, "left contactor" (counterclockwise rotation, reverse rotation), results in counterclockwise rotation RotL of the motor M.

[0037] The computing and control device GG can, on the one hand, control the reversing contactor circuits WS, Q1, Q2 via signal lines 21, 22, for example, closing or opening the two contactors Q1 and Q2, and, on the other hand, correlate the current and voltage values ​​obtained from the current and voltage measuring device UM and further process them, for example, to calculate the active power of the motor M based on the current and voltage values. The computing and control device GG can be connected to a computer network C via a signal line 31, from which it receives commands, for example, for controlling the reversing contactor circuits WS, Q1, Q2, or it can transmit data, for example, the calculated value of the active power of the motor M, to the computer network C.

[0038] Siemens AG offers the "SIMOCODE pro" engine management system. For each branch, the system consistently consists of a basic device, the "SIMOCODE basic unit" (which corresponds to the computing and control unit GG), and a separate current / voltage sensing module, the "SIMOCODE combined current / voltage measuring module" (which corresponds to the current and voltage measuring unit UM). The "basic unit" and "combined current / voltage measuring module" are electrically connected to each other via a connecting cable via a system interface and can be mechanically connected as a single unit (sequentially) or installed separately (side by side).

[0039] Figure 1The arrangement shown is advantageous for associating current values ​​with voltage values, since the current and voltage detection by the current and voltage measuring device UM takes place at the same location upstream of the reversing contactors WS, Q1, Q2, i.e. upstream of the location where the reversal takes place: the current and voltage values ​​detected in the individual phase conductors therefore correspond to one another. However, for reasons of space, Figure 1 The arrangement shown is not possible in many cases, for example in the case of inserts (bucket or panel) in motor control centers (MCCs).

[0040] Figure 2 FIG1 shows how the current and voltage measuring device UM detects the current value and voltage value in the load circuit L. To this end, as shown in FIG1 Figure 2 As shown, the current and voltage measuring device UM has, on the one hand, a feedthrough transformer for current measurement, wherein the phase conductors L1, L2, L3 to be measured are respectively passed through a cable duct 10, 14 of the current and voltage measuring device UM, where they form the primary circuit of the feedthrough transformer, and, on the other hand, screw terminals 11 for voltage measurement, which are electrically connected to the phase conductors L1, L2, L3 to be measured by means of an electrically conductive connection 40 for tapping the phase conductors L1, L2, L3 of the load circuit L. To process the measured values, the current and voltage measuring device UM has a processing unit 12, to which the secondary winding 13 of the feedthrough transformer for current measurement and the live line for voltage measurement are led.

[0041] Figure 3 An alternative known circuit arrangement for associating current values ​​with corresponding voltage values ​​is shown. This circuit arrangement has a multiphase load circuit L, in which electrical energy is transmitted from a power source 100 to a motor M. In the load circuit L, viewed in the direction from the power source 100 to the motor M, a circuit breaker CB, a reversing contactor circuit WS, Q1, Q2, and a current and voltage measuring device UM are connected in the following order.

[0042] about Figure 3 For a description and function of the electrical components of the illustrated alternative circuit arrangement, refer to Figure 1 and Figure 2 The description of the figures of the first circuit arrangement shown applies analogously to the alternative circuit arrangement.

[0043] Figure 3 The arrangement shown is advantageous for associating current values ​​with voltage values, since the current and voltage detection by the current and voltage measuring device UM takes place at the same location downstream of the reversing contactor circuit WS, Q1, Q2, i.e. downstream of the location where the reversal takes place: the current and voltage values ​​detected in the individual phase conductors therefore correspond to one another. Figure 3In the illustrated arrangement, when both reversing contactors Q1 and Q2 are open (motor off), the current and voltage measuring device UM downstream of the reversing contactor circuits WS, Q1, Q2 cannot check whether the voltage of the power supply 100 is present at the voltage source-side connection point 5 downstream of the circuit breaker CB, i.e., whether the circuit breaker contacts are conducting current. Consequently, there is no information regarding the switching readiness of the circuit breaker CB, which could be a prerequisite for reconnecting the load circuit after a fault. Consequently, monitoring functions that require voltage detection, such as automatic restart after a power outage (AWE), cannot be implemented.

[0044] Figure 4 A circuit arrangement according to the invention for associating current values ​​with corresponding voltage values ​​is shown. The circuit arrangement according to the invention is designed similarly to Figure 3 The circuit arrangement shown, i.e. in the load circuit L, is connected in the following order, as seen in the direction from the power supply 100 to the motor M, with the circuit breaker CB, the reversing contactor circuit WS, Q1, Q2 and the current and voltage measuring device UM. Figure 3 As in the circuit arrangement shown, the current measurement is carried out at the location of the current and voltage measuring device UM downstream of the circuit breaker CB and the reversing contactor circuit WS, Q1, Q2.

[0045] according to Figure 4 The circuit arrangement according to the invention is Figure 3 The circuit arrangement shown in FIG. 1 differs in that the voltage measurement is: Figure 3 In the circuit arrangement shown in FIG, the voltage measurement is also carried out at the location of the current and voltage measuring device UM downstream of the circuit breaker CB and the reversing contactor circuit WS, Q1, Q2, whereas in accordance with Figure 4 In the circuit arrangement according to the invention, the voltage tapping point 7 is located between the circuit breaker CB and the reversing contactor circuit WS, Q1, Q2, that is, at the voltage source side connection point 5 of the load circuit L of the reversing contactor circuit WS, Q1, Q2.

[0046] The voltage is measured between the circuit breaker CB and upstream of the reversing contactor circuit WS and transmitted to the current and voltage measuring device UM via an electrically conductive connection 40. The phase sequence of the voltage is independent of whether the "right contactor" Q1 or the "left contactor" Q2 of the reversing contactor circuit WS is activated. Conversely, the current is measured downstream of the reversing contactor circuit WS, and its phase sequence depends on whether the "right contactor" Q1 or the "left contactor" Q2 is activated. The measured voltage and current values ​​are received and further processed by the current and voltage measuring device UM and, if necessary, transmitted to the computing and control unit GG.

[0047] The voltage u and current i need to be measured at different locations in the circuit arrangement. This allows voltage measurements to be made to identify whether the circuit breaker CB is closed, even when the reversing contactor circuit WS is closed. Therefore, the voltage u is measured between the circuit breaker CB and the reversing contactor circuit WS, providing information about the circuit breaker CB's readiness for closing. Although the voltage u and current i are measured on different sides of the reversing contactor circuit WS, and therefore the correct correlation between the current and voltage depends on the resulting phase conductor arrangement in the reversing contactor circuit WS, the present invention makes it possible to achieve a correct correlation between the current and voltage values.

[0048] According to a first embodiment, the computing and control device GG determines whether the phase conductors L1, L2, and L3 of the load circuit L are arranged via a reversing contactor circuit WS in a first phase conductor arrangement LR, in which the direction of rotation of the motor is positive RotR (clockwise), or via a second phase conductor arrangement LL, in which the direction of rotation of the motor is negative RotL (counterclockwise). Since the computing and control device GG controls the reversing contactor circuit WS via signal lines 21 and 22 and determines which of the two contactors Q1 and Q2 is to be opened and, by locking, which of the two contactors Q1 and Q2 is to be closed, this information is stored in the computing and control device GG, for example, in its data memory SGG. This information regarding the currently existing phase conductor arrangement LR and LL allows the detected current values ​​to be correctly associated with the corresponding detected voltage values.

[0049] The processor PGG of the computing and control device GG, which controls the contactors Q1 and Q2 of the reversing contactor circuit WS, reads information about which contactors Q1 and Q2 are switched on from the data memory SGG of the computing and control device GG and transmits it to the current and voltage measuring device UM via a signal line 30. The current and voltage measuring device UM can then measure correctly correlated current and voltage values ​​without having to determine the actual phase conductor arrangement and phase sequence beforehand. This has the advantage that the system can immediately operate with the correct phase sequence after one of the contactors Q1 and Q2 is switched on; thus, undesirable delays are avoided when calculating electrical variables that depend on the current and voltage values, such as active power.

[0050] According to a second embodiment, the computing and control device GG determines corresponding current and voltage values ​​based on an analysis of detected current and voltage values, performed by a processor PGG of the computing and control device GG. The current values ​​i in the different phase conductors L1, L2, and L3 and the voltage values ​​u in the different phase conductors L1, L2, and L3 each exhibit a characteristic pattern of change over time. By analyzing the time series of the current values ​​i and the voltage values ​​u, the computing and control device GG can determine which current and voltage values ​​correspond to each other. Based on this, the detected current value i can be correctly associated with the corresponding detected voltage value u.

[0051] The current and voltage measuring device UM can also independently identify the correct correlation between the detected current and voltage values ​​by analyzing the detected current values ​​i and voltage values ​​u, and independently apply this correlation to the detected current and voltage values. This analysis is performed by the processor PUM of the current and voltage measuring device UM. The current and voltage measuring device UM can also calculate active power and transmit the calculation result to the calculation and control device GG via a signal line 30. For example, the current and voltage measuring device UM can first temporarily store the detected current and voltage values ​​in a data memory SUM of the current and voltage measuring device UM, and then, after the processor PUM of the current and voltage measuring device UM has determined the correct correlation between the current and voltage values, calculate the active power of the motor, for example.

[0052] Figure 5 An alternative embodiment of a circuit arrangement is shown. Figure 4 The embodiment shown differs in that Figure 5 In the embodiment shown, the voltage tapping point 7 is located directly at the output terminal 8 of the circuit breaker CB. The tapped voltage is transmitted from the output terminal 8 via an electrically conductive connection 40 to the current and voltage measuring device UM.

[0053] Figure 6A flow chart shows a method for associating current values ​​i with corresponding voltage values ​​u in a multi-phase load circuit L, wherein electrical energy is transmitted from a voltage source 100 to a motor M, and reversing contactor circuits WS, Q1, Q2 connected to the load circuit L enable a change in the direction of rotation RotR, RotL of the motor M via two different phase conductor arrangements LR, LL. In a first step 61, a current value i is detected in the phase conductors L1, L2, L3 of the load circuit L downstream of the reversing contactor circuits WS, Q1, Q2, as viewed in the direction of electrical energy transmission. In a second step 62, a voltage value u is detected in the load circuit L upstream of the reversing contactor circuits WS, Q1, Q2, as viewed in the direction of electrical energy transmission, by tapping at least one voltage in the load circuit L. In a third step 63, information I about the phase conductor arrangements WS, LR, LL present at the time of detecting the current value i and the voltage value u is provided. Based on the information I provided, it is determined in a fourth step 64 whether the association is carried out in a first manner 65, so that the detected current value i corresponds to the detected voltage value u according to the phase conductor arrangement LR, which leads to a clockwise rotation of the motor RotR, or whether the association is carried out in a second manner 66, so that the detected current value i corresponds to the detected voltage value u according to the phase conductor arrangement LL, which leads to a counterclockwise rotation of the motor RotL.

[0054] Figure 7 A motor control center 1 is shown, consisting of three metal switch panels 1.1, 1.2, and 1.3 connected to each other by connecting bolts. Switch panels 1.1, 1.2, and 1.3 draw power from a common busbar located in busbar compartment 2 of motor control center 1. Each switch panel 1.1, 1.2, and 1.3 has multiple vertically stacked inserts 9. Each insert can be operated by a pushbutton panel 4 and opened by an insert handle 3. A circuit device according to the present invention is disposed in at least one insert 9 of motor control center 1.

[0055] Reference Signs List

[0056] 1 Motor Control Center

[0057] 1.1 Switch Panel

[0058] 1.2 Switch Panel

[0059] 1.3 Switch Panel

[0060] 2 Busbar room

[0061] 3 Insert the handle (Unit Operating Handle)

[0062] 4 Push Button Area (English: Push Button Area)

[0063] 5 WS grid-side connection point

[0064] 6 WS motor side connection point

[0065] 7 Voltage measuring point

[0066] 8 CB output terminal

[0067] 9 Insert (English: Withdrawable unit oder Drawer, withdrawable unit or drawer)

[0068] 10 Phase input from the grid side

[0069] 11 Phase input from the grid side

[0070] 12 processing units

[0071] 13 Current transformer

[0072] 14 Phase output to motor

[0073] 21 signal lines

[0074] 22 signal lines

[0075] 30 signal lines

[0076] 31 signal lines

[0077] 40 Conductive connection for measuring the phase conductors of the load circuit

[0078] 61 First Step

[0079] 62 Step 2

[0080] 63 Step 3

[0081] 64 Step 4

[0082] 65 First-order association

[0083] 66 Relation in the Second Way

[0084] 100 Voltage network, voltage source

[0085] C Computer Network

[0086] CB circuit breaker

[0087] GG computing and control unit

[0088] I Information

[0089] L Load circuit

[0090] L1 Phase conductor 1

[0091] L2 Phase conductor 2

[0092] L3 Phase conductor 3

[0093] LR right-hand phase conductor arrangement

[0094] LL Left-handed phase conductor arrangement

[0095] M Electrical equipment, motors

[0096] PGG GG's processor

[0097] PUM UM's processor

[0098] Q1 right contactor, first contactor of WS

[0099] Q2 left contactor, second contactor of WS

[0100] SGG GG data storage

[0101] SUM UM data storage

[0102] UM Current and Voltage Measuring Devices

[0103] WS reversing contactor circuit

[0104] RotR M right rotation

[0105] RotL M left rotation

Claims

1. A method for associating current values ​​(i) with corresponding voltage values ​​(u) in a multiphase load circuit (L), wherein electrical energy is transmitted from a voltage source (100) to a motor (M), and a reversing contactor circuit (WS, Q1, Q2) connected to the load circuit (L) enables a change of rotation direction (RotR, RotL) of the motor (M) via two different phase conductor arrangements (LR, LL), the method comprising the following steps: - detecting the current value (i) in the phase conductors (L1, L2, L3) of the load circuit (L) downstream of the reversing contactor circuit (WS, Q1, Q2), as viewed in the direction of electrical energy transmission, - detecting a voltage value (u) in the load circuit (L) upstream of the reversing contactor circuit (WS, Q1, Q2) by tapping at least one voltage in the load circuit (L), as viewed in the direction of electrical energy transmission, - providing information about the phase conductor arrangement (LR, LL) present at the time of detecting the current value (i) and the voltage value (u); - Correlating the detected current value (i) with the corresponding detected voltage value (u) based on the provided information.

2. The method according to claim 1, wherein Information about the phase conductor arrangement (LR, LL) present at the time of detecting the current value (i) and the voltage value (u) is supplied from a data memory (SGG) to a computing and control device (GG), which determines the phase conductor arrangement (LR, LL) by controlling the reversing contactor circuit (WS, Q1, Q2).

3. The method according to any one of the preceding claims, comprising the following steps: - performing a time analysis of the detected current value (i) and the detected voltage value (u); and - extracting, based on the performed analysis, information about the phase conductor arrangement (LR, LL) present at the time of detecting the current value (i) and the voltage value (u); - temporarily storing the extracted information in a data memory (SUM) from which said information is provided.

4. A method according to any one of the preceding claims, wherein The active power of the motor (M) is calculated based on the current value (i) and the voltage value (u) that are correlated with each other.

5. A circuit device comprising: - a multiphase load circuit (L) for transmitting electrical energy from a voltage source (100) to a motor (M), a reversing contactor circuit (WS, Q1, Q2) connected to the load circuit (L), which enables a change of direction of rotation (RotR, RotL) of the electric machine (M) via two different phase conductor arrangements (LR, LL), a current and voltage measuring device (UM) for detecting current values ​​(i) and voltage values ​​(u) in phase conductors (L1, L2, L3) of a load circuit (L) and for associating a detected current value (i) with a corresponding detected voltage value (u), a data memory (SUM, SGG) for providing information about the phase conductor arrangement (LR, LL) present at the time of detecting the current value (i) and the voltage value (u); - a voltage tapping device (7, 11, 40) for tapping at least one voltage (u) in a phase conductor (L1, L2, L3) of a load circuit (L); - an electric line (40) for supplying at least one measured voltage (u) to the current and voltage measuring device (UM), in - current detection by the current and voltage measuring device (UM) downstream of the reversing contactor circuit (WS, Q1, Q2), seen in the direction of electrical energy transmission from the voltage source (100) to the motor (M), and - Viewed in the direction of electrical energy transmission from the voltage source (100) to the motor (M), voltage tapping is performed upstream of the reversing contactor circuit (WS, Q1, Q2) by the voltage tapping device (7, 11, 40).

6. The circuit arrangement according to claim 5 , comprising: - a calculation and control device (GG) for calculating the active power of the motor (M) based on the current value (i) and the voltage value (u) which are correlated with each other.

7. The circuit arrangement according to claim 5 or 6, comprising: A circuit breaker (CB) connected to the load circuit (L) upstream of the reversing contactor circuit (WS, Q1, Q2), viewed in the direction of electrical energy transmission from the voltage source (100) to the motor (M).

8. The circuit arrangement according to claim 7, wherein: The voltage measuring device (7, 11, 40) directly measures voltage at the circuit breaker (CB).

9. The circuit arrangement according to any one of claims 5 to 8, wherein: The current and voltage detection module (UM) has, for detecting a current value (i), at least one through-current measuring transformer, through which the individual phase conductors (L1, L2, L3) of the load circuit (L) are passed.

10. An insert (9) for a motor control center (1) comprising a circuit arrangement according to any one of claims 5 to 9.

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