Inverter control system and inverter control method

Abstract

The present application relates to an inverter control system and an inverter control method. Even if a part of inverter connected in parallel has failed, the operation of an elevator can be continued. An inverter control system supplies power to a motor driving an elevator by N (N is an integer of 2 or more) inverters connected in parallel and controls each inverter connected in parallel, and in the inverter control system, a failure signal receiving section (192) receives an abnormal signal of an inverter in units of groups in which the N inverters connected in parallel are divided into a plurality of groups, and a gate command section (191) causes an inverter of a group other than a group in which the failure signal receiving section receives an abnormal signal to operate.

Description

TECHNICAL FIELD

[0001] The present application relates to an inverter control system and an inverter control method. BACKGROUND

[0002] An elevator or the like uses an alternating-current motor as a power source. In order to control the operating state of the alternating-current motor, the voltage and frequency of the power source are converted by an inverter. For example, in the case of an elevator provided in a building, a three-phase alternating-current power source supplied from a power company is converted in voltage and frequency by an inverter, and the converted alternating-current power source is supplied to an alternating-current motor that constitutes a traction machine.

[0003] In the case where the voltage and frequency of a three-phase alternating-current power source are converted by an inverter, specifically, the three-phase alternating-current power source is converted into a direct-current power source by a converter, and the converted direct-current power source is set to an alternating-current power source of a desired voltage and frequency by an inverter. Here, the converter and the inverter can have the same basic structure, and in this case, only the direction of operation is opposite. In the following description, the case where an inverter is described, but the converter is also included except for the case where it is specifically distinguished and described.

[0004] In the case where an inverter is used as a device for power source control of an elevator or the like, a plurality of inverters are connected in parallel in multiple stages corresponding to the required power source capacity, and the plurality of inverters are simultaneously processed. That is, an inverter is constituted by a semiconductor switch such as an IGBT (Insulated Gate Bipolar Transistor), and since there is a limit to the current and voltage that can pass through one semiconductor switch, the required power source capacity is ensured by connecting a plurality of inverters in parallel. For example, in the case where an inverter of 200 kW output is constituted, four inverters of 50 kW output are connected in parallel to ensure 200 kW.

[0005] In Patent Literature 1, a technology is described in which, in the case where a plurality of inverter devices are constituted, when an abnormality is detected in any inverter device, the operation of the inverter device in which the abnormality is detected is stopped. In the technology described in Patent Literature 1, the abnormality of the inverter device is detected for each of the U phase, the V phase, and the W phase, and a U phase abnormality signal or the like is detected for each phase.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: JP Patent Application Laid-Open No. 2015-29393

[0009] As described in Patent Literature 1, in a case where the structure is provided in which the abnormality of the inverter device is detected for each of U phase, V phase, and W phase, in a case where the inverter device is configured by a plurality of units, it is difficult to determine the inverter unit in which the failure has occurred. For example, in a case where the abnormality of the U phase is detected, it is difficult to determine which unit of the plurality of units the abnormality of the U phase is, and it cannot be said that appropriate abnormality detection is performed.

[0010] Therefore, the inverter device in which the abnormality is detected cannot be used until the failure of the semiconductor switch or the like is replaced. For example, in a case where the inverter device that drives an elevator has an abnormality, until the failure of the corresponding inverter device is recovered, the elevator becomes a state in which it cannot be used. SUMMARY

[0011] The present application aims to provide an inverter control system and an inverter control method in which, even in a case where a failure has occurred in a part of the inverters connected in parallel, the operation of the elevator can be continued.

[0012] In order to solve the above problem, for example, the following structure is adopted.

[0013] The present application includes various means for solving the above problem, and if one example is given, it is an inverter control system that supplies power to a motor that drives an elevator by N (N is an integer of 2 or more) inverters connected in parallel, and controls each of the inverters connected in parallel, the inverter control system including: a failure signal receiving section that receives an abnormality signal of the inverter in units of groups in which the N inverters connected in parallel are divided into a plurality of groups; and a gate command section that causes the inverters of the group other than the group in which the failure signal receiving section receives the abnormality signal to operate.

[0014] EFFECT OF THE INVENTION

[0015] According to the present application, since the abnormality of the inverter is detected in units of groups, as for the inverter in which the abnormality is not detected, it is caused to operate, and even in a case where the abnormality has occurred in a part of the inverters, the elevator can continue to operate.

[0016] The above problem, structure, and effect other than the above are made clear by the following description of the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a diagram that shows the schematic structure of the circuit of the inverter device and the elevator controlled by the inverter control system of an embodiment example of the present application.

[0018] Figure 2 is a diagram that shows Figure 1 the configuration example of the inverter device shown in FIG. 1.

[0019] Figure 3is a perspective view showing the shape of one unit of an inverter device controlled by the inverter control system of an embodiment example of the present application.

[0020] Figure 4 is a block diagram showing a configuration example of the inverter control system of an embodiment example of the present application.

[0021] Figure 5 is a flowchart showing an example of control processing of the inverter control system of an embodiment example of the present application.

[0022] Explanation of Reference Signs

[0023] 11...three-phase AC power supply, 12...power filter section, 13...reactor, 14...motor, 15...rope wheel, 16...main sling, 18...load sensor, 19...counterweight, 100...inverter device, 101...handle, 102, 103...terminal section, 102U, 102V, 102W...terminal, 103...terminal section, 103U...terminal, 104-U, 104-V, 104-W, 105-P, 105-N...terminal, 107...frame, 109...control panel, 110-190...parallel inverter, 111, 112, 121, 122, 131, 132, 141, 142...inverter unit, 111-C, 112-U1...capacitor, 111-F1, 111-F2, 111-F3...cooling fan, 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, 111-W2...semiconductor switch, 190...inverter control device, 191...gate command section, 192...fault signal receiving section, 193...fault countermeasures section DETAILED DESCRIPTION

[0024] An inverter control system of an embodiment example of the present application (hereinafter referred to as "the present example") will be described below with reference to the accompanying drawings.

[0025] The inverter control system of the present example is a system for an inverter device that supplies power to a traction machine of an elevator as a hoist.

[0026] [Structure of Inverter Device]

[0027] Figure 1 The circuit structure of the inverter device 100 is shown. Further, the outline structure of an elevator to which power is supplied by the inverter device 100 is described in Figure 1

[0028] ​The inverter device 100 has a first parallel inverter 110, a second parallel inverter 120,..., and an Nth parallel inverter 190 (N is an integer of 2 or more).

[0029] Two inverter units are connected in series in each parallel inverter 110 to 190. For example, the first parallel inverter 110 connects two inverter units 111 and 112 in parallel. The inverter unit 111 functions as a converter that converts the three-phase AC power source 11 into DC, and has two semiconductor switches in each of the U phase, the V phase, and the W phase, for a total of six semiconductor switches 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, and 111-W2.

[0030] Further, the inverter unit 111 is connected to a capacitor 111-C that smoothes the power source after conversion into DC.

[0031] In addition, a power filter section 12 is connected between the three-phase AC power source 11 and the inverter unit 111.

[0032] The inverter unit 112 functions to convert the DC obtained in the inverter unit 111 into a three-phase AC power source, and has two semiconductor switches in each of the U phase, the V phase, and the W phase, for a total of six semiconductor switches 112-U1, 112-U2, 112-V1, 112-V2, 112-W1, and 112-W2. In the inverter unit 112, a capacitor 112-C is also connected on the DC side.

[0033] The second parallel inverter 120 to the Nth parallel inverter 190 also have two inverter units 121 and 122 to 191 and 192. For example, the inverter unit 121 of the second parallel inverter 120 has six semiconductor switches 121-U1, 121-U2, 121-V1, 121-V2, 121-W1, and 121-W2, and functions to convert a three-phase AC power source into a DC power source. Further, the inverter unit 122 of the second parallel inverter 120 has six semiconductor switches 122-U1, 122-U2, 122-V1, 122-V2, 122-W1, and 122-W2, and functions to convert a DC power source into a three-phase AC power source.

[0034] Further, the inverter unit 191 of the Nth parallel inverter 190 has six semiconductor switches 191-U1, 191-U2, 191-V1, 191-V2, 191-W1, and 191-W2, and functions to convert a three-phase AC power source into a DC power source. Further, the inverter unit 192 has six semiconductor switches 192-U1, 192-U2, 192-V1, 192-V2, 192-W1, and 192-W2, and functions to convert a DC power source into a three-phase AC power source.

[0035] For each of the two inverter units 121, 122 to 191, 192 of the second parallel inverter 120 to the Nth parallel inverter 190, capacitors 121-C, 122-C to 191-C, 192-C are also connected.

[0036] The semiconductor switches (121-U1, etc.) configured in each inverter unit 111, 112 to 191, 192 are composed of semiconductor elements such as IGBTs, and are controlled by the inverter control unit 200 described later. Figure 4 The on / off state is controlled by the inverter units 112-192 that obtain three-phase AC power from each of the parallel inverters 110-190. In this case, the voltage and frequency for elevator drive are set by controlling the on / off state of the inverter units 112-192 that obtain three-phase AC power from each of the parallel inverters 110-190.

[0037] The three-phase AC power obtained from the inverter units 112 to 192 of each parallel inverter 110 to 190 is supplied to the motor (e.g., a three-phase synchronous motor) 14 of the traction machine of the elevator via the reactor 13.

[0038] Here, the elevator side structure is briefly described. A sheave 15, rotating in conjunction with the motor 14, winds the main hoisting cable 16. One end of the main hoisting cable 16 is connected to the car 17, and the other end is connected to a counterweight 19. The car 17 is raised and lowered by the rotation of the motor 14. A load sensor 18, serving as a load detection unit for detecting the load on the car 17, is installed in the car 17.

[0039] In addition, the inverter 100 may be installed, for example, in the machine room of an elevator.

[0040] [Inverter configuration example]

[0041] Figure 2 This shows a configuration example of the inverter device 100 in this example.

[0042] Figure 2 The example inverter 100 is configured as a four-parallel structure consisting of the first parallel inverter 110 to the fourth parallel inverter 140.

[0043] Each parallel inverter 110 to 140 has 2 inverter units, so there are a total of 8 inverter units 111 to 141 and 112 to 142.

[0044] Here, as Figure 2 As shown, in this example, the inverter unit 100 arranges eight inverter units 111-141 and 112-142 vertically on the control panel 109. That is, in Figure 2In the example, the inverter units are configured from top to bottom in the order of 111, 121, 131, 141, 112, 122, 132, 142. However... Figure 2 The configuration state of the unit shown is an example, and other configuration orders can also be set.

[0045] Each inverter unit 111, 112, 121, 122, 131, 132, 141, and 142 has six semiconductor switches. Figure 2 (Not shown in the image), three cooling fans are installed in each unit.

[0046] For example, cooling fans 111-F1, 111-F2, and 111-F3 are installed in inverter unit 111. Similarly, cooling fans labeled "F1, F2, F3" are also installed in inverter units 121-141 and 112-142, as indicated by the end of the reference numerals for each unit. Additionally, handles 101 are installed at the left and right ends of each inverter unit 111-142.

[0047] Furthermore, the four inverter units 111, 121, 131, and 141, which function as converters, are connected in parallel with the three terminals 102U, 102V, and 102W of the terminal section 102. The three terminals 102U, 102V, and 102W of the terminal section 102 are connected in parallel with... Figure 1 The three-phase AC power supply shown is connected on side 11.

[0048] Furthermore, the four inverter units 112, 122, 132, and 142, which operate as inverters, are connected in parallel to the three terminals 103U, 103V, and 103W of the terminal section 103. The three terminals 103U, 103V, and 103W of the terminal section 103 are connected in parallel with... Figure 1 The motor shown is connected to side 14.

[0049] In addition, each of the parallel inverters 110 to 140 is set to have the same maximum output current.

[0050] [Structure of the inverter unit]

[0051] Figure 3 This is a three-dimensional diagram showing the structure of one inverter unit 111.

[0052] The other inverter units 112 to 142 also have the same structure as inverter unit 111.

[0053] The inverter unit 111 mounts three cooling fans 111-F1, 111-F2, 111-F3 on the front side of the frame 107 that serves as a heat sink. Also, the inverter unit 111 has six semiconductor switches 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, 111-W2. In this example, it is a structure of an inverter unit in a case where a 2in1 type IGBT module is used, but a 1in1, 6in1 type can also be used. Further, a capacitor 111-C or the like is arranged in the inverter unit 111. Handles 101 are mounted on the left and right end portions on the front side of the frame 107.

[0054] Also, on the front side of the upper portion of the frame 107, three-phase AC-side terminals 104-U, 104-V, 104-W are arranged, and on the rear side of the upper portion of the frame 107, DC-side terminals 105-P, 105-N are arranged.

[0055] In a case where the inverter unit 111 operates as a converter, the three-phase AC-side terminals 104-U, 104-V, 104-W are connected to the three-phase AC power supply 11 Figure 1 ). In addition, in a case where the inverter unit 121 operates as an inverter, the three-phase AC-side terminals 104-U, 104-V, 104-W are connected to the motor 14 side.

[0056] The DC-side terminals 105-P, 105-N are connected to the DC-side terminals (not shown) of the inverter unit 112 of the same parallel inverter 110.

[0057] [Control structure of inverter device]

[0058] Figure 4 The structure of the inverter device 100 and the inverter control section 200 used in the inverter control system of this example is shown. Figure 4 The inverter device 100 of this example is provided with a structure of six parallel inverters 110 to 160. The six parallel inverters 110 to 160 are divided into three groups.

[0059] That is, the first parallel inverter 110 and the second parallel inverter 120 are provided as the first group inverter 100a. Further, the third parallel inverter 130 and the fourth parallel inverter 140 are provided as the second group inverter 100b. Furthermore, the fifth parallel inverter 150 and the sixth parallel inverter 160 are provided as the third group inverter 100c.

[0060] The semiconductor switches arranged in each of the parallel inverters 110 to 160 are turned on / off by an instruction from a gate command section 191 of the inverter control device 190.

[0061] In this case, each of the parallel inverters 110 to 160 is configured to be supplied with the gate command via the switches 119 to 169, respectively, and the control to stop the operation of each of the parallel inverters 110 to 160 can be performed.

[0062] Further, the inverter control system of this example is provided with a failure signal receiving section 192 and a failure response section 193.

[0063] The failure signal receiving section 192 performs a failure signal receiving process of receiving abnormality signals of the inverters 110 to 160.

[0064] Here, the failure signal receiving section 192 receives abnormality signals individually in each group. That is, the failure signal receiving section 192 receives abnormality signals when an abnormality occurs in the first group inverter 100a, abnormality signals when an abnormality occurs in the second group inverter 100b, and abnormality signals when an abnormality occurs in the third group inverter 100c, individually.

[0065] The abnormality signals received by the failure signal receiving section 192 include abnormality signals indicating that the semiconductor switches of the parallel inverters 110 to 160 are not operating, abnormality signals indicating abnormalities in the currents and voltages of the parallel inverters 110 to 160, abnormality signals indicating abnormalities in the temperatures of the parallel inverters 110 to 160, and the like.

[0066] The failure response section 193 determines in which group of the parallel inverters 110 to 160 an abnormality has occurred, and supplies information of the determined group in which an abnormality has occurred to the gate command section 191.

[0067] The gate command section 191 that receives the information of the group in which an abnormality has occurred from the failure response section 193 performs a control process of bringing the switches of the lines of the parallel inverters of the corresponding group to an off state and operating only the parallel inverters of the remaining groups. For example, when an abnormality signal is received from the first group inverter, the switches 119 and 129 are brought to an off state, and only the parallel inverters 130 and 140 of the second group and the parallel inverters 150 and 160 of the third group are operated.

[0068] Further, the failure response section 193 determines the number of parallel inverters that can operate normally in addition to the group in which an abnormality has occurred. Then, the failure response section 193 determines the maximum current that can be supplied to the motor 14 (M) based on this determination, and instructs the elevator control section, not shown, to limit the load and speed of the elevator based on the determined maximum current. Figure 1 ) based on this determination.

[0069] In addition, in the case where the failure response section 193 determines that an abnormality has occurred in the first group inverter 100a, the failure response section 193 brings the switches 119 and 129 to an off state, and operates only the parallel inverters 130 and 140 of the second group and the parallel inverters 150 and 160 of the third group. Figure 4In the embodiment, the failure signal receiving section 192 and the failure coping section 193 are prepared outside the inverter control device 190, but the failure signal receiving section 192 and the failure coping section 193 can be provided inside the inverter control device 190.

[0070] [Control processing of inverter control device]

[0071] Figure 5 is a flowchart of a processing example indicating a case where the failure signal receiving section 192 receives an abnormal signal.

[0072] First, the failure signal receiving section 192 determines whether an abnormal signal is received (step Sll). In a case where no abnormal signal is received in step Sll (NO in step Sll), the gate command section 191 causes all groups of the parallel inverters 110 to 160 to operate.

[0073] Then, in a case where the failure signal receiving section 192 receives an abnormal signal in step Sll (YES in step Sll), the failure coping section 193 determines whether it is an abnormal signal of the inverter 100a of the first group (step S12).

[0074] In step S12, in a case where it is not an abnormal signal of the inverter 100a of the first group (NO in step S12), the failure coping section 193 determines whether it is an abnormal signal of the inverter 100b of the second group (step S13).

[0075] In step S13, in a case where it is not an abnormal signal of the inverter 100b of the second group (NO in step S13), it is determined that the abnormal signal detected in step Sll is an abnormal signal of the inverter 100c of the third group. Then, the gate command section 191 turns off the switches 159 and 169, and stops the inverter 100c (the parallel inverters 150 and 160) of the third group (step S14).

[0076] Then, in the elevator control device not shown, the operation of the elevator is continued by supplying power to the inverters 100a and 100b of the two groups excluding the stopped inverter 100c of the third group, according to an instruction from the failure coping section 193 (step S15). At this time, since the current supplied to the motor 14 is limited, the elevator control section performs a boarding limit process in which the loading rate of the car 17 is limited from 100% at normal times, and a travel speed limit process.

[0077] Further, in step S12, in a case where it is an abnormal signal of the inverter 100a of the first group (YES in step S12), the failure coping section 193 further determines whether there is an abnormal signal with respect to the inverter 100b of the second group (step S16).

[0078] In step S16, in a case where the inverter 100b of the 2nd group is not outputting the abnormal signal (NO in step S16), the failure coping section 193 determines whether or not the inverter 100c of the 3rd group is also outputting the abnormal signal (step S17).

[0079] In step S17, in a case where the inverter 100c of the 3rd group is not outputting the abnormal signal (NO in step S17), the failure coping section 193 determines that only the inverter 100a of the 1st group is abnormal. At this time, the door control command section 191 stops the inverter 100a of the 1st group, and stops the power supply based on the inverter 100a of the 1st group (step S18).

[0080] That is, in step S18, the power supply to the motor 14 is performed by the inverters 100b and 100c of the 2nd and 3rd groups.

[0081] Then, the routine proceeds to step S15, and the elevator control device continues the operation of the elevator using the power supplied by the inverters 100b and 100c of the 2nd and 3rd groups on the basis of the implementation of the boarding restriction or the speed restriction.

[0082] In step S17, in a case where the inverter 100c of the 3rd group is also outputting the abnormal signal (YES in step S17), the failure coping section 193 determines that the inverter 100a of the 1st group and the inverter 100c of the 3rd group are abnormal. At this time, the door control command section 191 stops the inverters 100a of the 1st group and 100c of the 3rd group, and stops the power supply based on the inverters 100a of the 1st group and 100c of the 3rd group (step S19).

[0083] Then, the routine proceeds to step S15, and the elevator control device continues the operation of the elevator using the power supplied by the inverter 100b of the 2nd group on the basis of the implementation of the boarding restriction or the speed restriction.

[0084] Further, in step S16, in a case where the inverter 100b of the 2nd group is outputting the abnormal signal (YES in step S16), it is determined whether or not the inverter 100c of the 3rd group is also outputting the abnormal signal (step S20).

[0085] In step S20, in a case where the inverter 100c of the 3rd group is outputting the abnormal signal (YES in step S20), since all of the inverters 100a to 100c of the groups are outputting the abnormal signal, the door control command section 191 stops the power supply based on all of the inverters 100a to 100c of the groups, and stops the elevator (step S21).

[0086] Further, in a case where the abnormal signal of the inverter 100b of the second group is output (YES in step S13), the fault coping section 193 further determines whether the abnormal signal is being output from the inverter 100c of the third group (step S23).

[0087] Then, the process proceeds to step S15, and the elevator control device continues the operation of the elevator on the basis of the ride restriction or the speed restriction with the power supplied only by the inverter 100c of the third group.

[0088] Further, in a case where the abnormal signal of the inverter 100b of the second group is output (YES in step S13), the fault coping section 193 further determines whether the abnormal signal is being output from the inverter 100c of the third group (step S23).

[0089] In a case where the abnormal signal is being output from the inverter 100c of the third group (YES in step S23), the fault coping section 193 determines that the inverter 100b of the second group and the inverter 100c of the third group are abnormal. At this time, the gate command section 191 stops the inverter 100b of the second group and the inverter 100c of the third group (step S24).

[0090] Then, the process proceeds to step S15, and the elevator control device continues the operation of the elevator on the basis of the ride restriction or the speed restriction with the power supplied only by the inverter 100a of the first group.

[0091] In a case where the abnormal signal is not being output from the inverter 100c of the third group (NO in step S23), the fault coping section 193 determines that only the inverter 100b of the second group is abnormal. At this time, the gate command section 191 stops the inverter 100b of the second group (step S25).

[0092] Then, the process proceeds to step S15, and the elevator control device continues the operation of the elevator on the basis of the ride restriction or the speed restriction with the power supplied by the inverter 100a of the first group and the inverter 100c of the third group.

[0093] [Effects of the control by the inverter control device]

[0094] By the control processing by the inverter control device 190 of the present example, even in a case where a group of a part of the inverters 100 has failed, the power supply to the motor 14 can be continued with the inverters of the remaining groups. Therefore, even if a part of the inverters has failed, the elevator can continue the operation. Figure 5 The control processing illustrated in FIG. 8 is performed by the inverter control device 190 of the present example. In the control processing, even in a case where a group of a part of the inverters 100 has failed, the power supply to the motor 14 can be continued with the inverters of the remaining groups. Therefore, even if a part of the inverters has failed, the elevator can continue the operation.

[0095] In the event of a failure of a part of the inverters, the maximum current supplied to the motor 14 is limited in accordance with the number of remaining normal groups, and therefore, the boarding of the car 17 is restricted, the speed is limited, but the effect of continuing the service based on the elevator is obtained.

[0096] Further, as shown in Figure 4 by configuring the groups that detect abnormal signals from a plurality of parallel inverters, the number of sensors that detect abnormal signals can be made less than the number of parallel inverters, and abnormal signals can be detected with a simple structure.

[0097] Further, in the event of a failure of a part of the groups of inverters, by restricting the boarding of the car 17, limiting the speed, the inverters of the groups that are operating are not overloaded, and the life of the inverters is not shortened by the continuation of operation in an overloaded state.

[0098] [Modified Example]

[0099] In addition, the embodiment examples explained so far have been explained in detail in order to easily explain the present application, but are not necessarily limited to having all the structures explained.

[0100] For example, in the flowchart of Figure 5 , the processing in the case where six parallel inverters 110 to 160 are provided is explained, but the present application can be applied to the processing of selecting the inverters that operate in the same processing in the case where N (N is an integer of 2 or more) parallel inverters are provided.

[0101] Further, regarding the configuration of each of the inverter units 111 to 142 shown in Figure 2 , this is an example, and other structures can also be used.

[0102] Further, in the embodiment examples explained above, the control of the inverter device that supplies power to the motor of the elevator is applied, but can also be applied to the motor of an elevator other than an elevator. For example, the control of the inverter device that supplies power to the motor of an elevator such as an escalator can also be applied.

[0103] Further, in the configuration diagram of the control device shown in Figure 4 , only the control lines and information lines that are considered necessary for explanation are shown, but all the control lines and information lines are not necessarily shown in the product. In fact, it can be considered that almost all the structures are connected to each other.

Claims

1. An inverter control system, comprising setting parallel inverters connected in parallel as separate groups, supplying power to the motor driving an elevator by providing multiple parallel inverters in multiple groups, and controlling the parallel inverters in each group, characterized in that it includes: A fault signal receiving unit, which receives abnormal signals from the parallel inverters individually, group by group; and The gating command unit, when the fault signal receiving unit receives an abnormal signal from any of the groups, causes the parallel inverters of the groups that received the abnormal signal to stop, and causes the parallel inverters of the groups that did not receive the abnormal signal to start operating. The elevator passenger limit is set according to the number of groups that cause the parallel inverters to operate, corresponding to the number of groups that the gate control command unit causes to operate.

2. The inverter control system according to claim 1, characterized in that, When the fault signal receiving unit receives an abnormal signal from the entire group, it stops the elevator.

3. An inverter control method, comprising setting parallel inverters connected in parallel as separate groups, supplying power to the motor driving the elevator by preparing multiple parallel inverters of multiple groups, and controlling the parallel inverters of each group, characterized in that the inverter control method includes: Fault signal reception and processing, receiving abnormal signals from the parallel inverters individually on a group-by-group basis; and In the control process, when an abnormal signal from any of the groups is received in the fault signal receiving process, the parallel inverters of the groups that received the abnormal signal are stopped, and the parallel inverters of the groups that did not receive the abnormal signal are put into operation. The number of groups that make the parallel inverters work is used to limit the number of passengers on the elevator.

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