Verification of Phase Currents in a Polyphase System

Abstract

To ensure the safe operation of a polyphase system (1) in the case of multiple (n) phases (L1, …, L n ), several (m) phase groups (G1, …, G n ) are provided, each including a part of the phases (L1, …, L m ). The phase currents (i1, …, i m ) of the several (m) phase groups (G1, …, G n ) converge into group total currents (i m , …, i g1 ) at group nodes (K1, …, K gm ), and group total current measurement values (i Mg1 , …, i Mgm ) of the group total currents are obtained. The current measurement values (i m , …, i M1 ) related to the several (m) phase groups (G1, …, G Mn ) are added to obtain group sums (i G1 , …, i Gm ), and the group sums (i G1 , …, i Gm ) are compared with the group total current measurement values (i Mg1 , …, i Mgm ) to verify the phase currents (i1, …, i n ) of each phase (L1, …, L n ) to ensure safe operation.

Description

Field of the Invention

[0001] The present invention relates to a method for the safe operation of a multiphase system, in which phase currents flow in a plurality of phases of the multiphase system, and in which current measurement values of the phase currents are obtained from phase current sensors in order to verify the phase currents. Furthermore, the present invention relates to a multiphase system comprising a plurality of phases, in which phase currents flow in the respective phases, and in which current sensors for obtaining current measurement values of the phase currents are provided. Background Art

[0002] In a multiphase system (for example, an electromagnetic transmission unit such as a long stator linear motor or a planar motor), the phase currents of the individual phases are determined. In order to ensure that no errors occur when determining or processing the phase currents, it is generally necessary to verify the phase currents, that is, to ensure that the determined phase currents are correct. One possibility for verifying the determined phase currents is to use Kirchhoff's total current rule. According to Kirchhoff's first law, the sum of all currents in a node is equal to zero. In other words, the sum of all currents flowing into a node corresponds to the sum of all currents flowing out of that node. Therefore, in order to verify the phase currents, the phase currents can be combined into a phase current sum in a common node and the phase current sum can be determined. If the phase current sum determined in the node corresponds to the sum of the individual determined phase currents, the phase currents can be verified, which means that the measurement of the phase currents is considered valid. EP 3 109 999 A2 discloses such a method for verifying the phase currents of a multiphase system.

[0003] However, when determining the individual phase currents, the allowed tolerances, that is, the maximum allowed errors, must be taken into account separately. However, errors occurring in the phases within the tolerance range (for example, measurement errors of the phase currents) cannot be detected thereby. Since the maximum allowed errors must be taken into account for all phase currents and the phase currents are added together to obtain the phase current sum, the maximum allowed errors are also added together. This means that the maximum allowed error of the phase current sum corresponds to the sum of the maximum allowed errors of the individual phase currents. Thereby, the allowed error of the phase current sum increases linearly in proportion to the number of phases (and thus the number of phase currents to be determined). Due to the higher maximum allowed error of the phase current sum, the accuracy of the verification of the phase currents is lower, since it deteriorates linearly with the increase in the number of phases.

[0004] Therefore, especially in the case of a higher number of phases, the allowed error of the phase current sum can reach such a high value that a meaningful verification of the phase currents based on the phase current sum is impossible, whereby the safe operation of the multiphase system cannot be ensured. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a method for the safe operation of a multiphase system even in the case of a large number of phases.

[0006] According to the present invention, this task is solved in the following manner: there are provided several phase groups each including a part of each phase, wherein the phase currents of the several phase groups converge into a group total current at a group node; and a group total current measurement value of the group total current is obtained from a group current sensor, wherein current measurement values related to the several phase groups are added by a group summing unit to obtain a group sum, and wherein the group sum is compared with the group total current measurement value by a group comparison unit to verify the phase currents of each phase to ensure the safe operation of the polyphase system.

[0007] Furthermore, this task is solved by a polyphase system in which there are provided several phase groups each including a part of each phase; wherein there is provided a group node, and the phase currents of the several phase groups converge into a group total current at the group node; wherein there is provided a group current sensor for obtaining a group total current measurement value of the group total current; wherein there is provided a group summing unit which is designed to add current measurement values related to the several phase groups of the phase currents to obtain a group sum; and wherein there is provided a group comparison unit which is designed to compare the group sum with the group total current measurement value to verify the phase currents of each phase to ensure the safe operation of the polyphase system.

[0008] When determining the current measurement value of the phase current, the maximum deviation between the current measurement value in the form of the maximum allowable error and the actual phase current must be considered. According to the present invention, a part of the phases in at least one phase group converge at a group node, whereby a group total current is obtained for the corresponding phase current at the group node. Furthermore, current measurement values of the phases related to at least one phase group are added to obtain a group sum. Thereby, the maximum allowable error is obtained for the group sum as the sum of the allowable errors of the phases included in the corresponding phase group. In addition, the group sum is compared with the group total current measurement value to verify the phase currents of the phase group.

[0009] Instead, if all the phases of the polyphase system are only converged into a total current at a total node and the current measurement values of all the phases are added to obtain a sum, then the sum of the allowable errors of all the phases will be obtained as the maximum allowable error.

[0010] According to the present invention, by combining a part of the phases into a phase group, a maximum allowable error of the group total current measurement value smaller than that for all total current measurement values is obtained. Thereby, the phase current verification can be performed with greater accuracy. This means that the tolerance for the deviation from the group total current to the group total current measurement value is lower, and thus smaller errors can also be detected within the scope of the verification. By combining the phases in the phase group, the accuracy of the verification is independent of the number of phases or phase currents in the polyphase system. Through this verification with high accuracy, the safe operation of the polyphase system can be ensured. With a lower error tolerance, it is ensured that no or only small errors occur during the measurement and / or processing of the phase current. If the verification fails, at least one action (e.g., outputting an optical and / or acoustic signal) can be triggered by the action unit. Similarly, in the case of verification failure, the polyphase system or a part thereof can be shut down as an action. For example, it can also be an action to prevent the polyphase system from being turned on. Similarly, a signal can be generated as an action, and this signal is further processed by, for example, the control unit of the polyphase system.

[0011] The principle of forming a phase group to improve the accuracy of reliably determining the phase current can be applied to any physical measurement principle of current measurement and can also be applied to heterogeneous systems with different current measurements. Therefore, the phase group can be formed independently of the measurement principle used (using a shunt, using the Hall effect, etc.), where in the method according to the present invention, the same or at least partially different measurement principles can be used to measure different currents.

[0012] Of course, in addition to the method according to the present invention, all phases can also be combined into a total current at the total node and the total current measurement value is determined, and this total current measurement value is compared with the sum of the current measurement values of all phases. However, the (additional) verification based on the total current suffers from the maximum allowable error which is the sum of the maximum allowable errors of all phases.

[0013] Preferably, the phase currents of all phases of the polyphase system are divided into several phase groups. In each phase group, the phase currents are respectively converged into a group total current at the group node, and the group total current measurement values of the group total currents are respectively obtained. Wherein in each phase group, the current measurement values of the phase currents are respectively added by the group summing unit to obtain the group sum, and wherein in each phase group, the group sum is respectively compared with the relevant group total current measurement value by the group comparison unit to verify the phase currents of all phases within the several phase groups.

[0014] By dividing all phases into phase groups, the phase currents of all phases can be verified. Thus, the maximum allowable error is obtained for each phase group as the sum of the allowable errors of the phases included in the corresponding phase group. Since each phase group only includes a part of the phases of the polyphase system, a smaller verified maximum allowable error is obtained than in the case of the total overall current as the maximum allowable error of the phases included in the phase group. Overall, verifying the accuracy of the phase currents of all phases depends on the maximum maximum allowable error of the phase groups involved.

[0015] The several phase groups can each include the same number of phases. This results in a symmetric and simple structure. The phase groups can also be nested within each other. However, each phase is preferably only included in one phase group, especially in the case where all phases are divided into phase groups.

[0016] Phase groups with different numbers of phases can also be provided. This can be particularly advantageous in cases where different maximum allowable errors are desired for determining the current measurement values of the corresponding phases. This situation can be especially in the case of using different sensors.

[0017] It can be advantageous to accommodate the phases with larger maximum allowable errors of their current measurement values in smaller phase groups (i.e., phase groups with fewer phases) and to accommodate the phases with smaller maximum allowable errors of their current measurement values in larger phase groups (i.e., phase groups with more phases).

[0018] Preferably, the current measurement values of the phase currents are reliably obtained in accordance with predefined safety requirements, where preferably, a single-error safety requirement is required as a safety requirement for determining the current measurement values.

[0019] If the determination of the current measurement values is carried out by means of sigma-delta (∑-Δ) conversion, this safety requirement can relate to the implementation in the FPGA and, in the case of LEM conversion, to the ADC converter.

[0020] The method according to the invention can be used in all polyphase systems with a plurality (n>2) of phases, especially in the case of long-stator linear motors or planar motors. If all phases of the polyphase system are combined into phase groups, a plurality (n>3) of phases are required. For example, in the case of four phases, two phase groups each with two phases can be provided. Description of the Drawings

[0021] In the following, the invention will be explained in more detail with reference to FIGS. 1 and Figure 2 and FIGS. 1 and Figure 2 exemplarily, schematically and non-limitingly show advantageous design configurations of the invention. Shown in the drawings are:

[0022] FIG. 1 shows the verification of phase currents according to the prior art,

[0023] Figure 2 Verification of the phase currents in the respective phase groups is shown. Detailed implementation

[0024] FIG. 1 shows the verification of the n phase currents i 1 、…、i n in a multiphase system 1 according to the prior art. The multiphase system 1 can be, for example, an electromagnetic transmission system (e.g., a long stator linear motor or a planar motor) and includes a plurality (n) of phases L 1 、…、L n . The phase currents i 1 、…、i n flow in each phase L 1 、…、L n , and in each of the phases L 1 、…、L n there is provided a phase current sensor S 1 、…、S n for determining the current measurement values i M1 、…、i Mn of the phase currents i 1 、…、i n . The respective current measurement values i M1 、…、i Mn have a maximum error ε 1 、…、ε n relative to the actual phase currents i 1 、…、ε n respectively, for example due to system-related measurement errors. The maximum errors ε 1 、…、ε n must be taken into account separately during verification. Thus, the first current measurement value i M1 consists of the first phase current i 1 and the first maximum error ε 1 : i M1 = i 1 + ε 1 , the second current measurement value i M2 consists of the second phase current i 2 and the second maximum error ε 2 : i M2 = i 2 + ε 2 , and so on, and the nth current measurement value i Mn consists of the nth phase current i n and the nth maximum error ε n : i Mn = i n + ε n .

[0025] The maximum error ε1 , …, ε n itself can each be assumed to be positive or negative, where the error tolerance band can also be assumed to be the maximum possible error ε 1 , …, ε n . The positive maximum error ε 1 , …, ε n means that the relevant current measurement values i M1 , …, i Mn exceed the maximum possible value of the corresponding phase current i 1 , …, i n . The negative maximum error ε 1 , …, ε n means that the relevant current measurement values i M1 , …, i Mn are lower than the maximum possible value of the corresponding phase current i 1 , …, i n . The maximum error ε 1 , …, ε n means the tolerance band, which assumes that the relevant current measurement values i M1 , …, i Mn exceed and / or are lower than the maximum possible value of the corresponding phase current i 1 , …, i n .

[0026] In the summing unit E0, the current measurement values i M1 , …, i Mn are added together to obtain the sum of the measurement values Thus, the sum of the measurement values i M includes the sum of n phase currents i 1 , …, i n , plus the sum of the maximum errors ε 1 , …, ε n : Furthermore, the phase currents i 1 , …, i n converge into the total current i g at the total node K g , from which it follows that the total current i g = i 1 + i 2 + … + i n . Here, the total current measurement value i g of the total current i g is determined by means of the total current sensor S Mg , where the total current measurement value i Mg also has the maximum error ε g , and thus results from the total current i g and the maximum error ε g in: i Mg= i g + ε g 。

[0027] In principle, the positive maximum error ε 1 、…、ε n and / or the negative maximum error ε 1 、…、ε n can be added separately, especially when assuming different values for the positive maximum error and the negative maximum error ε 1 、…、ε n 。If the error tolerance band is assumed to be the maximum possible error ε 1 、…、ε n , then the summation of the maximum error ε 1 、…、ε n means the expansion of the error tolerance band. For easier illustration, the addition of the maximum error ε 1 、…、ε n is shown only in a general way. In principle, the summation of the maximum error ε 1 、…、ε n and / or the positive maximum error ε 1 、…、ε n and / or the maximum error ε 1 、…、ε n in the form of a tolerance band can be performed for the maximum error ε 1 、…、ε n .

[0028] Now, the comparison unit V0 compares the sum of the measured values i M with the total current measured value i Mg to determine whether there is a sufficiently precise match to verify the phase current i 1 、…、i n . For example, if the verification fails, action A is triggered.

[0029] However, the maximum error ε M1 、…、ε Mn of the current measured values i 1 、…、ε n and the maximum error ε Mg of the total current measured value i g must be considered during verification, as generally shown in FIG. 1. That is, the maximum error ε M1 、…、ε Mn of the current measured values i 1 、…、i n relative to the phase current i 1 、…、ε n is included in the sum of the measured values i M . In addition, when the sum of the measured values i MCompared with the measured total current i Mg (shown in Fig. 1 as ), not only the maximum errors ε M1 ,..., ε Mn of the measured currents i 1 ,..., ε n are considered, but also the maximum error ε Mg of the measured total current i g with respect to the total current i g is considered.

[0030] Thus, especially in the case of a higher number (n) of phases L 1 ,..., L n , a higher maximum allowable total error for verifying the phase currents i 1 ,..., i n is obtained. Therefore, an error that causes the measured total current i Mg to deviate from the sum of the measured values i M by less than the maximum allowable total error cannot be detected. This occurring error can involve the phase currents i 1 ,..., i n , or be the accumulation of multiple occurring errors involving multiple phase currents i 1 ,..., i n .

[0031] Assuming that the maximum errors ε M1 ,..., ε Mn of the measured currents i 1 ,..., ε n and the maximum error ε Mg of the measured total current i g respectively correspond to the same maximum error ε 1 = ε 2 =... = ε n = ε x (not shown), then the sum of the phase currents i 1 ,..., i n plus n times the maximum error ε x gives the sum of the measured values i M : i M = i 1 + i 2 +,..., + i n + nε x . In contrast, the measured total current i Mg corresponds to the sum of the phase currents i 1 ,..., i n plus the maximum error ε x : i Mg = ig +ε x = i 1 + i 2 +,... + i n +ε x 。Now, in order to be able to perform the comparison of the sum of the measured values i M with the total current measured value i Mg a maximum allowable total error of magnitude ε =(n + 1)ε V must be considered as the error limit, where the factor n results from the determination of the current measured values i x 、...、i M1 and the number corresponding to the phases L Mn 、...、L 1 while the additional factor 1 is attributed to the measurement of the total current measured value i n 、...、L Mg .

[0032] This means that during the verification process, an error that causes the total current measured value i Mg to deviate from the sum of the measured values i M by less than the maximum allowable total error ε V =(n + 1)ε x cannot be detected.

[0033] If the long stator linear motor operates as a polyphase system 1, for example, having a plurality (n = 42) of phases L 1 、...、L n＝42 , then when adding the current values i M1 、...、i Mn to obtain the sum of the measured values i M and comparing it with the total current measured value i g of the total current i Mg the maximum allowable total error ε V = ε 1 +ε 1 +... ε n＝42 +ε g .

[0034] Assuming that the maximum error ε M1 、...、ε Mn＝42 of the current measured values i 1 、...、ε n＝42 and the maximum error ε Mg of the total current value i g correspond to a maximum error ε x of 100 mA respectively, then the maximum allowable total error is ε V =(n + 1)ε x= 43 * 100 mA = 4.3 A. This means that no current measurement value i less than the maximum allowable total error ε will be detected within the verified range V = 4.3 A for the current measurement value i M1 ,..., i Mn of each individual error that occurs or the cumulative errors that add up to the total error

[0035] In contrast, in Figure 2 a preferred design of the method according to the present invention and the device according to the present invention is shown. Also shown is a polyphase system 1 having a plurality (n) of phases L 1 ,..., L n wherein in each phase L 1 ,..., L n a phase current sensor S for measuring the corresponding phase current i 1 ,..., i n is provided 1 ,..., S n . For each phase current i 1 ,..., i n the current measurement value i M1 ,..., i Mn is determined. Each of the current measurement values i M1 ,..., i Mn again has a maximum error ε 1 ,..., ε n . Thus, as described above with reference to FIG. 1, the first phase current i 1 together with the first maximum error ε 1 results in the first current measurement value i M1 : i M1 = i 1 + ε 1 , the second phase current i 2 together with the second maximum error ε 2 results in the second current measurement value i M2 : i M2 = i 2 + ε 2 , up to the nth current measurement value i n composed of the nth phase current i n and the nth maximum error ε Mn : i Mn = i n + ε n .

[0036] However, different from FIG. 1, a plurality (m > 1) of phase groups G 1 ,..., G n are provided, each including a part of the phases L 1 ,..., L m . According to the present invention, each phase group G1 , …, G m includes multiple (n) phases L 1 , …, L n is part of. By phase group G 1 , …, G m includes the phase L 1 , …, L n The number of which is thus called the phase number p of the group 1 , …, p m . Phase group G 1 , …, G m The phase number p of the group 1 , …, p m can be the same, or at least partially vary between phase groups G 1 , …, G m . In Figure 2 , each phase group G 1 , …, G m each includes three phases, whereby the phase number p of each phase group G 1 , …, G m is 3 1 , …, p m .

[0037] It can also be stipulated that the total number of m phase groups G 1 , …, G m only includes part of the phases L 1 , …, L n of the polyphase system 1. However, thereby only for the phases L 1 , …, L n of this part are the corresponding phase currents i 1 , …, i n verified.

[0038] In each phase group G 1 , …, G m , the current measurement values i 1 , …, L n of the relevant phases L M1 , …, i Mn are respectively added by the group summation units E 1 , E 2 , …, E m to obtain the group sum i G1 , …, i Gm .

[0039] Group comparison units V 1 , …, V m and / or group summation units E 1 , E 2 , …, E mcan be an integrated component of a polyphase system, for example integrated on the control unit of a polyphase system 1 (e.g., an electromagnetic transmission system). This also applies to the actuating unit as long as an actuating unit is provided. Group comparison unit V 1 ,..., V m and / or group summation unit E 1 , E 2 ,..., E m and / or the actuating unit can be implemented as hardware or software, respectively.

[0040] Thus, for example, for the first phase group G 1 , the first measured current value i M1 , the second measured current value i M2 and the third measured current value i M3 are added together to obtain the first group sum i G1 . Thus, the first group sum i G1 therefore includes the sum of the first, second, and third phase currents i 1 , i 2 , i 3 plus the sum of the first, second, and third maximum errors ε 1 , ε 2 , ε 3 : i G1 = i 1 + i 2 + i 3 + ε 1 + ε 2 + ε 3 , the second group sum i G2 includes the sum of the fourth, fifth, and sixth phase currents i 4 , i 5 , i 6 plus the sum of the fourth, fifth, and sixth maximum errors ε 4 , ε 5 , ε 6 : i G2 = i 4 + i 5 + i 6 + ε 4 + ε 5 + ε 6 , and so on, and the m-th group sum i Gm includes the sum of the (n - 2)-th, (n - 1)-th, and n-th phase currents i n-2 , i n-1 , i n plus the sum of the (n - 2)-th, (n - 1)-th, and n-th maximum errors ε n-2 , ε n-1 , ε n : i Gm = in-2 +i n-1 +i n +ε n-2 +ε n-1 +ε n 。

[0041] In addition, the phase currents i 1 、…、G m of each phase group G 1 、…、i n converge into the group total current i 1 、…、K m at the group nodes K g1 、…、i gm , and thus the sum of the phase currents i 1 、…、i n contained in the group respectively yields the corresponding group total currents i g1 、…、i gm . By using the group current sensors S g1 、…、S gm to respectively determine the group total current measurement values i g1 、…、i gm of the group total currents i Mg1 、…、i Mgm , where the group total current measurement values i Mg1 、…、i Mgm also have a maximum error ε g1 、…、i gm respectively relative to the relevant group total currents i g1 、…、ε gm .

[0042] Therefore, the first group total current measurement value i 1 of the first phase group G Mg1 is composed of, for example, the first, second, and third phase currents i 1 、i 2 、i 3 and the maximum error ε g1 , and so on.

[0043] According to the present invention, the group comparison units V 1 、…、V m respectively compare the group total current measurement values i Mg1 、…、i Mgm with the relevant group sums i G1 、…、i Gm (referred to as Figure 2 in to verify the phase currents i 1 、…、i n .

[0044] If the verification fails, i.e., if the corresponding group total current measurement values i Mg1 ,..., i Mgm deviate from the associated group sum i G1 ,..., i Gm an action A can be triggered by an action unit (not shown). As an action, for example, an optical and / or acoustic signal can be output and / or at least a part of the multiphase system 1 can be switched off.

[0045] The maximum errors ε 1 ,..., ε m of the current measurement values i M1 ,..., i Mn must be taken into account again in each group comparison unit V 1 ,..., ε n (on the group sums i G1 ,..., i Gm ) and the maximum errors ε Mg1 ,..., i Mgm of the corresponding group total current measurement values i g1 ,..., ε gm . Thereby, the maximum allowable group total errors ε 1 ,..., ε m for each phase group G V1 , ε V2 ,..., ε Vm only include the maximum errors ε 1 ,..., ε m of the current measurement values i 1 ,..., L n of the phases L M1 ,..., i Mn contained in the respective phase group G 1 ,..., ε n and the maximum errors ε Mg1 ,..., i Mgm of the associated group total current measurement values i g1 ,..., ε gm .

[0046] Thus, for example, when comparing the first group total current measurement value i Mg1 with the associated first group sum i G1 , only the maximum allowable group total error ε = ε VG1 + ε 1 + ε 2 + ε 3 + ε g1 is obtained for the first group G1. When comparing the second group total current measurement value i Mg2 with the associated second group sum i G2 , The maximum allowable total group error ε is obtained when... VG2 = ε 4 + ε 5 + ε 6 + ε g2 , …, when comparing the measured value i of the total current of the m-th group Mgm with the relevant total sum i of the m-th group Gm , the maximum allowable total group error ε is obtained = ε VGm = ε n-2 + ε n-1 + ε n + ε gm .

[0047] For the general case of phase group Gy, this means that the maximum allowable total group error ε Vgy consists of the maximum errors of phase group Gy: , where the number of phases p in the group y maximum errors (i.e., there is one maximum error for each phase included in each phase group Gy (p y is the number of phases in phase group Gy)) are added together, and additionally, the maximum error ε y of the measured value i of the total group current related to phase group G Mgy is considered, …, ε g1 , …, ε gm . Therefore, the maximum allowable total group error ε y for phase group G Vgy corresponds to when verifying (i.e., when comparing the measured values i of the total group current Mg1 , …, i Mgm with the relevant total sums i G1 , …, i Gm ), the maximum allowable total group error ε Vgy is considered. If the measured values i of the total group current Mg1 , …, i Mgm deviate from the relevant total sums i G1 , …, i Gm by more than the maximum allowable total group error ε Vgy , then the verification fails.

[0048] Again, assume that the maximum errors ε M1 , …, ε Mn of the current measurement values i 1 , …, ε n and the maximum errors ε Mg1 , …, ε Mgm of the measured values i of the total group current g1 , …, ε gm correspond to the maximum error ε x (not shown) respectively. Thus, the relevant phase current i1 、…、i n The sum of... and i plus three times the maximum error ε x (Here it is three times because the number of phases in each group p 1 、p 2 、…、p m is 3 respectively) gives the group sum i 1 、…、G m for each phase group G G1 、…、i Gm : i G1 = i 1 + i 2 + i 3 + 3ε x , i G2 = i 4 + i 5 + i 6 + 3ε x , i Gm = i n-2 + i n-1 + i n + 3ε x 。

[0049] In addition, the sum of the phase currents i 1 、…、G m contained in the groups G 1 、…、i n plus the maximum error ε gives the measured value i 1 、…、K m of the total group current at the group nodes K Mg1 、…、i Mgm : i Mg1 = i g1 + ε x = i 1 + i 2 + i 3 + ε x , i Mg2 = i g2 + ε x = i 4 + i 5 + i 6 + ε x , …, i Mgm = i gm + ε x = i n-2 + i n-1 + i n + ε x 。Now, in order to be able to verify the phase currents i 1 、…、G m in the phase groups G 1 、…、i nwhile the group sum i G1 、…、i Gm is compared with the associated group total current measurements i Mg1 、…、i Mgm it is necessary to consider only for each group G 1 、…、G m the corresponding maximum allowable group total error ε 1 、…、G m of size ε VG1＝ (3 + 1)ε x 、ε VG2＝ (3 + 1)ε x 、...、ε VGm＝ (3 + 1)ε x where the corresponding factor 3 corresponds to the number of phases p VG1 、p VG1 、…、p 1 and results from the current measurements i 2 、…、i m contained in the phases of the corresponding group G 1 、…、G m where the additional factor 1 results from the determination of the group total current measurements i M1 、…、i Mn 、…、i Mg1 、…、i Mgm .

[0050] Now, if a long stator linear motor with a plurality (n = 42) of phases L 1 、…、L n is operated again as a polyphase system 1 compared to the prior art, then when dividing the phases L 1 、…、L n into a number m = 14 phase groups G 1 、…、p m each having a number of phases p 1 、…、G m＝14 and a maximum error ε 1 、…、G m of for example 100 mA per phase group G x the maximum allowable group total error ε VG1 、…、ε VG14 results where ε VG1 、…、ε VG14 =(p + 1)ε x = 4 * 100 mA = 0.4 A.

[0051] This means that in the scope of verification only deviations less than the maximum allowable group total error ε VG =(p + 1)ε xEach error of = 0.4 A. Therefore, the verification according to the present invention has much higher accuracy compared to the verification carried out via the total current measurement value i corresponding to FIG. 1 Mg has much higher accuracy, which is 10.75 times higher in the described example. Therefore, the verification according to the present invention has high accuracy, thereby ensuring safer operation of the polyphase system 1.

Claims

1. A method for the safe operation of a multiphase system (1) wherein the phase current (i 1 ,…,i n ) are respectively in the multiple (n) phases (L 1 ,…,L n ) flows, and wherein in order to verify that the phase current (i 1 ,…,i n ) and from the phase current sensor (S 1 ,…,S n ) to obtain the phase current (i 1 ,…,i n ) of the current measurement value (i M1 ,…,i Mn ), Characterized in that, There are provided several (m) phase groups (G 1 ,..., L n ) including a part of the phases (L 1 ,..., G m ), wherein the phase currents (i 1 ,..., G m ) of the several (m) phase groups (G 1 ,..., i n ) converge into a group total current (i 1 ,..., K m ) at group nodes (K g1 ,..., i gm ), and group total current measurement values (i g1 ,..., S gm ) of the group total current are obtained from group current sensors (S Mg1 ,..., i Mgm ). The current measurement values (i 1 , E 2 ,..., E m ) related to the several (m) phase groups (G 1 ,..., G m ) are added by group summing units (E M1 ,..., i Mn ) to obtain group sums (i G1 ,..., i Gm ), and the group sums (i 1 ,..., V m ) are compared with the group total current measurement values (i G1 ,..., i Gm ) by group comparison units (V Mg1 ,..., i Mgm ) to verify the phase currents (i 1 ,..., L n ) of the phases (L 1 ,..., i n ) so as to ensure the safe operation of the polyphase system (1).

2. The method according to claim 1, Characterized in that, All phases (L 1 ,..., L n ) of the polyphase system (1) have phase currents (i 1 ,..., i n ) that are divided into several (m) phase groups (G 1 ,..., G m ). And in each phase group (G 1 ,..., G m ), the phase currents (i 1 ,..., i m ) of the phase group (G 1 ,..., G n ) are combined into a group total current (i g1 ,..., i gm ) at a group node, and group total current measurement values (i Mg1 ,..., i Mgm ) of the group total current are obtained respectively. In each phase group (G 1 ,..., G m ), group summing units (E 1 , E 2 ,..., E m ) sum the current measurement values (i 1 ,..., i n ) of the phase currents (i M1 ,..., i Mn ) to obtain a group sum (i G1 ,..., i Gm ). And in each phase group (G 1 ,..., G m ), group comparison units (V 1 ,..., V m ) compare the group sum (i G1 ,..., i Gm ) with the relevant group total current measurement value (i Mg1 ,..., i Mgm ) to verify the phase currents (i 1 ,..., i n ) of all phases.

3. The method according to claim 1 or 2, Characterized in that, Several (m) phases (G 1 ,..., G m ) each include the same number (p 1 ,..., p m ) of phases (L 1 ,..., L n ).

4. The method according to any one of claims 1 to 3, Characterized in that, Reliably obtain the current measurement values (i 1 ,..., i n ) of the phase currents (i M1 ,..., i Mn ) according to the pre-given safety requirements.

5. The method according to any one of claims 1 to 4, Characterized in that, in the case of verification failure, an action is triggered by the action unit.

6. The method according to claim 5, Characterized in that, output an optical and / or acoustic signal as an action, and / or shut down at least a part of the multiphase system.

7. A polyphase system (1) comprising a plurality (n) of phases (L 1 ,..., L n ), wherein phase currents (i 1 ,..., i n ) flow in the respective phases (L 1 ,..., L n ), and wherein phase current sensors (S 1 ,..., S n ) are provided for obtaining current measurements (i M1 ,..., i Mn ) of the phase currents (i 1 ,..., i n ), Characterized in that, There are provided several (m) phase groups (G 1 ,..., L n ) including a part (p 1 ,..., p m ) of the phases (L 1 ,..., G m ), and group nodes are provided therein. The phase currents (i 1 ,..., i m ) of the several (m) phase groups (G 1 ,..., G n ) converge into a group total current (i g1 ,..., i gm ) at the group nodes. Group current sensors (S Mg1 ,..., S Mgm ) for obtaining group total current measurement values (i g1 ,..., i gm ) of the group total current are provided. Group summing units (E 1 , E 2 ,..., E m ) are provided. The group summing units are designed to add current measurement values (i 1 ,..., i n ) of the phase currents (i M1 ,..., i Mn ) related to the several (m) phase groups to obtain a group sum (i G1 ,..., i Gm ), and group comparison units (V 1 ,..., V m ) are provided. The group comparison units are designed to compare the group sum (i G1 ,..., i Gm ) with the group total current measurement values (i Mg1 ,..., i Mgm ) to verify the phase currents (i 1 ,..., i n ) of the phases so as to ensure the safe operation of the polyphase system (1).

8. The multiphase system (1) according to claim 7, Characterized in that, The several (m) phase groups (G 1 ,..., G m ) include all phases (L 1 ,..., L n ) of the polyphase system (1), where in each phase group (G 1 ,..., G m ) the phase currents (i 1 ,..., i m ) of the phase group (G 1 ,..., G n ) are combined into a group total current (i g1 ,..., i gm ) at a group node. Each phase group (G 1 ,..., G m ) is provided with a group summing unit (E 1 , E 2 ,..., E m ), and the group summing units are respectively designed to sum the current measurements (i 1 ,..., i n ) of the phase currents (i M1 ,..., i Mn ) to obtain a group sum (i G1 ,..., i Gm ), and each phase group (G 1 ,..., G m ) is provided with a group comparison unit (V 1 ,..., V m ), and the group comparison units are respectively designed to compare the group sums (i G1 ,..., i Gm ) with the associated group total current measurements (i Mg1 ,..., i Mgm ) to verify the phase currents (i 1 ,..., i n ) of all phases (L 1 ,..., L n ).

9. The multiphase system (1) according to claim 7 or 8, Characterized in that, There is an action unit, and the action unit is connected to the group comparison unit (V 1 ,..., V m ) and is designed to trigger an action when the verification fails.

10. The multiphase system (1) according to claim 9, Characterized in that, the action unit is designed to output an optical and / or acoustic signal, and / or shut down at least a part of the multiphase system.

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