A multi-motor starter for a gate hoist test platform

Abstract

This invention provides a multi-motor starter for a gate hoist testing platform, relating to the technical field of gate hoist testing platforms. It includes: a first resistance box, a second resistance box, and a third resistance box; the first resistance box is connected in series with the motor rotor of a 320t or 250t hoist; the second resistance box is connected in series with the motor rotor of a 160t-63t hoist; and the third resistance box is connected in series with the motor rotor of a 50t-25t hoist. The system obtains the target specifications of the gate hoist currently under test; connects to the target resistance box matching the currently under test; generates control commands corresponding to the currently under test gate hoist based on the target specifications; and controls the operation of each contactor corresponding to the target resistance box. This invention significantly reduces the number of resistance boxes, simplifies wiring and control complexity, and improves control reliability.

Description

Technical Field

[0001] This invention relates to the field of gate hoist test platform technology, and in particular to a multi-motor starter for a gate hoist test platform. Background Technology

[0002] In the field of gate hoist testing platforms, if one set of resistors is used for a gate hoist of a certain specification, and two sets are used for dual-motor drives, then approximately 168 boxes of resistors would be needed to cover all specifications of gate hoists on the market. Since only one gate hoist can be tested at a time, the maximum utilization rate of the resistors is only 12.5%, with the vast majority of resistors being idle, making this solution costly. If two sets of resistors are configured to cover all different specifications of gate hoists, the maximum utilization rate of the resistors is 100%, but then 36 boxes of resistors and 46 switching contactors would be required. This solution involves more contactors and more complex control, a large amount of wiring, lower reliability, and is more difficult to repair once a failure occurs. Summary of the Invention

[0003] To address the aforementioned technical problems, the technical solution adopted by this invention is as follows:

[0004] According to a first aspect of this application, a multi-motor starter for a gate hoist test platform is provided, comprising:

[0005] The system comprises a first resistance box, a second resistance box, and a third resistance box; wherein the first resistance box includes three terminals for connecting in series with the motor rotor of a 320t or 250t hoist gate opener; the second resistance box includes three terminals for connecting in series with the motor rotor of a 160t-63t hoist gate opener; and the third resistance box includes three terminals for connecting in series with the motor rotor of a 50t-25t hoist gate opener.

[0006] The first resistor box includes six sets of first resistor modules with preset resistance values. The six sets of first resistor modules are connected in series according to preset rules, and each first resistor module is connected in parallel with a first contactor.

[0007] The second resistor box includes six sets of second resistor modules with preset resistance values. The six sets of second resistor modules are connected in series according to preset rules, and each second resistor module is connected in parallel with a second contactor.

[0008] The third resistor box includes five sets of third resistor modules with preset resistance values. The five sets of third resistor modules are connected in series according to preset rules, and each third resistor module is connected in parallel with a third contactor.

[0009] Each of the first contactors, the second contactors, and the third contactors is communicatively connected to the processor. When the processor is running, it performs the following steps:

[0010] S100, obtain the target specifications of the gate hoist for the current test;

[0011] S200, according to the target specifications, connect the target resistor box that matches the gate opener of the current test;

[0012] S300, Based on the target specifications, generate the control command ZL corresponding to the gate hoist of the current test;

[0013] S400, according to ZL, controls the action of each contactor corresponding to the target resistor box to complete the starting process of the hoist motor of the gate hoist in the current test.

[0014] Optionally, the multi-motor starter further includes a fourth resistor box and a fifth resistor box; wherein the fourth resistor box is the same as the second resistor box, and the fifth resistor box is the same as the third resistor box; the fourth resistor box is used to connect in series with the motor rotor of the second winch gate opener of 160t-63t specifications; the fifth resistor box includes three terminals for connecting in series with the motor rotor of the second winch gate opener of 50t-25t specifications.

[0015] Optionally, when the processor is running, it is also used to perform the following steps:

[0016] S310, based on the target specifications and the preset truth table QT for the operation of the resistor switching contactor, determine the preset operation information of each contactor corresponding to the target resistor box; QT includes several rows and several columns, each row corresponds to a type of gate hoist, and each column corresponds to the operation information of a contactor corresponding to a different type of gate hoist.

[0017] S320, add the preset action information of each contactor corresponding to the target resistor box to the preset structure to obtain the control command ZL = (KM1, KM2, ..., KM) i (i = 1, 2, ..., 6), where KM i This refers to the preset action information of the i-th contactor corresponding to the target resistor box; KM i =(KM i，1 KM i，2 KM i，3 ); KM i，1 For information regarding whether the i-th contactor corresponding to the target resistor box has operated and whether it has operated prematurely, KM i，2 For the action sequence information of the i-th contactor corresponding to the target resistor box, KM i，3 The time interval between the action of the i-th contactor and the next contactor corresponding to the target resistor box.

[0018] Optionally, when the processor is running, it is also used to perform the following steps:

[0019] S410, traverse KM i If KM i，1 If the action information is preset or pre-set, then KM will be used. i The corresponding contactor is identified as the target contactor, resulting in a target contactor list A = (A1, A2, ..., A...). j A m ), j = 1, 2, ..., m; where A j The j-th target contactor is determined, and m is the number of target contactors determined.

[0020] S420, based on the chronological order of the actions of each target contactor in A, sort all target contactors in A to obtain a sorted list of target contactors B = (B1, B2, ..., B...). j B m ); where B j Let j be the target contactor obtained by sorting all target contactors in A;

[0021] S430, according to the arrangement order of each target contactor in B and the time interval between the action of each target contactor and the next contactor, the switching control of each target contactor is performed sequentially.

[0022] Optionally, B1 is a pre-action contactor, and when the processor is running, it is also used to perform the following steps:

[0023] S431, at a preset time before the start of the gate hoist in the current test, control B1 to be energized so as to cut off the resistor module connected in parallel with B1.

[0024] S432, when the hoist in the current test starts, controls B2 to be energized, corresponding to the interval KM. i，3 Then, control B3 to be powered on until B m Power on to complete the switching control of each target contactor in B.

[0025] Optional, KM i，3 The range is 1-3S.

[0026] Optionally, the total resistance of the first resistance box is 1.003Ω, the total resistance of the second resistance box is 0.725Ω, and the total resistance of the third resistance box is 1.35Ω.

[0027] The present invention has at least the following beneficial effects:

[0028] The present invention relates to a multi-motor starter for a gate hoist test platform, comprising: a first resistance box, a second resistance box, and a third resistance box; wherein, the first resistance box includes three terminals for series connection with the motor rotor of a 320t or 250t hoist gate hoist; the second resistance box includes three terminals for series connection with the motor rotor of a 160t-63t hoist gate hoist; and the third resistance box includes three terminals for series connection with the motor rotor of a 50t-25t hoist gate hoist. Thus, by using three resistance boxes to cover the motors of all hoist gate hoist specifications, the number of resistance boxes is greatly reduced, and the complexity of wiring and control is simplified, thereby improving control reliability.

[0029] Furthermore, each of the first contactors, the second contactors, and the third contactors are connected to the processor for communication. Then, based on the specifications of the hoist being tested, the processor automatically selects the corresponding target resistor box and generates corresponding control commands to complete the starting process of the hoist's winch motor according to the control commands, thereby automating the starting of the hoist's winch motor. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the first resistance box provided in an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the second resistance box provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the third resistance box provided in an embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0036] The following section will introduce a multi-motor starter used in a gate hoist test platform.

[0037] The multi-motor starter used for the gate hoist test platform includes, for example: Figure 1 The first resistance box R1 shown is as follows: Figure 2 The second resistor box R2 shown and as follows Figure 3 The third resistor box R3 is shown; wherein, the first resistor box R1 includes three terminals for series connection with the motor rotor of a 320t or 250t hoist gate opener; the second resistor box R2 includes three terminals for series connection with the motor rotor of a 160t-63t hoist gate opener; the third resistor box R3 includes three terminals for series connection with the motor rotor of a 50t-25t hoist gate opener; it should be noted that those skilled in the art can use existing resistor boxes and motor rotors to connect them according to actual needs, which will not be elaborated here.

[0038] In this embodiment, it can be understood that all gate hoists on the market are divided into three categories according to their lifting capacity: the first category is 320t and 250t specifications, the second category is 160t-63t specifications, and the third category is 50t-25t specifications. Each type of gate hoist uses a type of resistor box, which can greatly reduce the number of resistor boxes used and reduce costs.

[0039] The first resistor box R1 includes six sets of first resistor modules with preset resistance values. The six sets of first resistor modules are connected in series according to preset rules, and each first resistor module is connected in parallel to a first contactor.

[0040] like Figure 1 As shown, the first resistance box contains six sets of first resistance modules with preset resistance values, formed by connecting resistors in series and / or parallel. All the first resistance modules are connected in series, and the total resistance of the resistance box is 1.003Ω. Figure 1The resistance values ​​corresponding to KM106 are 0.68Ω, KM105 are 0.59Ω, KM104 are 0.379Ω, KM103 are 0.2Ω, KM102 are 0.101Ω, and KM101 are 0.045Ω. When the coil of KM106 is energized, the contacts of KM106 close, thus short-circuiting the first resistor module connected in parallel with KM106. The resistance value cut off is 0.68Ω - 0.59Ω = 0.09Ω. KM101-KM105 operate in the same way as KM106, and will not be described in detail here.

[0041] The second resistor box includes six sets of second resistor modules with preset resistance values. The six sets of second resistor modules are connected in series according to preset rules, and each second resistor module is connected in parallel with a second contactor.

[0042] like Figure 2 As shown, the second resistance box contains six sets of second resistance modules with preset resistance values, formed by connecting resistors in series and / or parallel. All the second resistance modules are connected in series, and the total resistance of the resistance box is 0.725Ω. Figure 2 The resistance values ​​corresponding to KM206, KM205, KM204, KM203, KM202, and KM201 are 0.009Ω, respectively. When the coil of KM206 is energized, the contacts of KM206 close, causing the second resistor module connected in parallel with KM206 to short-circuit. The resistance value cut off is 0.628Ω - 0.423Ω = 0.205Ω. The operation of KM201-KM205 is the same as that of KM206, and will not be described in detail here.

[0043] The third resistor box includes five sets of third resistor modules with preset resistance values. The five sets of third resistor modules are connected in series according to preset rules, and each third resistor module is connected in parallel to a third contactor.

[0044] like Figure 3 As shown, the third resistance box contains five sets of third resistance modules with preset resistance values, formed by connecting resistors in series and / or parallel. All the third resistance modules are connected in series, and the total resistance of the resistance box is 1.35Ω. Figure 2The resistance values ​​for KM305, KM304, KM303, KM302, and KM301 are 1.16Ω, 0.75Ω, 0.64Ω, 0.275Ω, and 0.068Ω, respectively. When the coil of KM305 is energized, the contacts of KM305 close, causing the third resistor module connected in parallel with KM305 to short-circuit. The resistance value cut off is 1.16Ω - 0.75Ω = 0.41Ω. KM301-KM304 operate in the same way as KM305, and will not be described in detail here.

[0045] Furthermore, the multi-motor starter also includes a fourth resistor box and a fifth resistor box; wherein, the fourth resistor box is the same as the second resistor box, and the fifth resistor box is the same as the third resistor box; the fourth resistor box is used to connect in series with the motor rotor of the second winch gate opener of 160t-63t specifications; the fifth resistor box includes three terminals for connecting in series with the motor rotor of the second winch gate opener of 50t-25t specifications; this configuration can match gate openers with dual winch motors.

[0046] Furthermore, each of the first contactors, each of the second contactors, and each of the third contactors are communicatively connected to the processor, which, when running, performs the following steps:

[0047] S100: Obtain the target specifications of the gate hoist for the current test.

[0048] In this embodiment, all contactors used are contactors with communication interfaces, which can control the action of the contactors through control commands issued by the processor; the target specification of the gate hoist in the current test can be the specification input by the user, for example, the specification of the gate hoist in the current test input by the user is 320t.

[0049] S200, according to the target specifications, connect the target resistor box that matches the gate opener of the current test.

[0050] In this embodiment, each resistance box is connected to the corresponding winch motor rotor through a corresponding resistance box contactor. After the target resistance box is determined according to the target specifications, the corresponding resistance box contactor of the target resistance box is turned on, so that the target resistance box is connected to the winch motor rotor of the gate hoist currently being tested.

[0051] S300, based on the target specifications, generate the control command ZL corresponding to the gate hoist of the current test.

[0052] In this embodiment, generating the control command ZL corresponding to the gate hoist of the current test according to the target specifications may include the following steps:

[0053] S310, based on the target specifications and the preset truth table QT for the operation of the resistor switching contactor, determines the preset operation information of each contactor corresponding to the target resistor box; QT includes several rows and several columns, each row corresponds to a type of hoist, and each column corresponds to the operation information of a contactor corresponding to a hoist of different specifications.

[0054] In this embodiment, the truth table QT of the resistor switching contactor is shown in Table 1.

[0055] Table 1. Truth Values ​​of Resistor Switching Contactor Operation

[0056]

[0057] In Table 1, + indicates that the contactor is energized and the corresponding resistor is cut off; + indicates that the corresponding contactor is not energized and the corresponding resistor is not cut off; zero position, early action means that the corresponding contactor needs to be energized for a preset time in advance to cut off the corresponding resistor in advance.

[0058] Based on the action information of each contactor in Table 1, the preset action information of each contactor corresponding to the target resistor box can be obtained by traversing through the data.

[0059] S320, add the preset action information of each contactor corresponding to the target resistor box to the preset structure to obtain the control command ZL = (KM1, KM2, ..., KM) i (i = 1, 2, ..., 6), where KM i This refers to the preset action information of the i-th contactor corresponding to the target resistor box; KM i =(KM i，1 KM i，2 KM i，3 ); KM i，1 For information regarding whether the i-th contactor corresponding to the target resistor box has operated and whether it has operated prematurely, KM i，2 For the action sequence information of the i-th contactor corresponding to the target resistor box, KM i，3 The time interval between the action of the i-th contactor and the next contactor corresponding to the target resistor box.

[0060] In this embodiment, a preset structure is provided, for example, ZL = (KM1, KM2, KM3, KM4, KM5, KM6), and the initial information of each element in the structure is empty; the preset action information of each contactor corresponding to the target resistor box is added to the preset structure to obtain the control command ZL.

[0061] In this embodiment, 0 can be used to indicate that the contactor does not operate, 1 indicates that the contactor operates, and 2 indicates that the contactor operates ahead of schedule. After the current contactor operates, a preset time interval is required before controlling the next contactor to operate. For example, the time interval between the operation of the i-th contactor corresponding to the target resistor box and the operation of the next contactor is 1-3 seconds, preferably 2 seconds.

[0062] S400, according to ZL, controls the action of each contactor corresponding to the target resistor box to complete the starting process of the hoist motor of the gate hoist in the current test.

[0063] In this embodiment, according to ZL, the operation of each contactor corresponding to the target resistor box is controlled to complete the starting process of the hoist motor of the gate hoist in the current test, which may include the following steps:

[0064] S410, traverse KM i If KM i，1 If the action information is preset or pre-set, then KM will be used. i The corresponding contactor is identified as the target contactor, resulting in a target contactor list A = (A1, A2, ..., A...). j A m ), j = 1, 2, ..., m; where A j Let m be the number of target contactors identified, where j is the j-th target contactor.

[0065] S420, based on the chronological order of the actions of each target contactor in A, sort all target contactors in A to obtain a sorted list of target contactors B = (B1, B2, ..., B...). j B m ); where B j Let j be the target contactor obtained by sorting all target contactors in A.

[0066] S430, according to the arrangement order of each target contactor in B and the time interval between the action of each target contactor and the next contactor, the switching control of each target contactor is performed sequentially.

[0067] Furthermore, step S430 may include the following steps:

[0068] S431, at a preset time before the start of the gate hoist in the current test, controls B1 to be energized so as to cut off the resistor module connected in parallel with B1.

[0069] S432, when the hoist in the current test starts, controls B2 to be energized, corresponding to the interval KM. i，3 Then, control B3 to be powered on until B mPower on to complete the switching control of each target contactor in B.

[0070] For example, the 320t and 250t fixed winch gate openers use a four-stage resistor switching starting method with a primary resistor constantly connected in series; the 25t and 160t fixed winch gate openers use a three-stage resistor switching starting method with a primary resistor constantly connected in series; the truth table of the resistor switching contactor operation is shown in Table 1, where "+" indicates that the contactor is energized and switching is interrupted. Figure 1 The corresponding resistors in the table, and the resistance values ​​of each cut-off resistor are shown in Table 2.

[0071] For example, before starting a 320t fixed winch gate hoist, KM105 is energized first, disconnecting the 0.211Ω resistor, and the rotor is connected in series with a 0.792Ω resistor. At the start of startup, firstly, KM104 is energized, disconnecting the 0.179Ω resistor, and the rotor is connected in series with a 0.613Ω resistor; secondly, KM103 is energized, disconnecting the 0.099Ω resistor, and the rotor is connected in series with a 0.514Ω resistor; thirdly, KM102 is energized, disconnecting the 0.056Ω resistor, and the rotor is connected in series with a 0.458Ω resistor; fourthly, KM101 is energized, disconnecting the 0.045Ω resistor, and the rotor is connected in series with a 0.413Ω resistor, completing the startup.

[0072] The starting methods for fixed winch gate openers ranging from 25t to 250t are similar and will not be elaborated here; if the fixed winch is driven by two motors, the contactor of the other motor is shown in parentheses in Table 1, and the motor starts in the same way as described above.

[0073] Table 2. Resistance values ​​for each level

[0074] 320T 250T 160T 100T 80T 63T 50T 40T 30T 25T 0.045 0.101 0.068 0.068 0.009 0.009 0.068 0.068 0.068 0.068 0.056 0.099 0.104 0.104 0.059 0.059 0.207 0.207 0.207 0.207 0.099 0.179 0.251 0.17 0.104 0.104 0.475 0.475 0.41 0.475 0.179 0.301 0.302 0.286 0.17 0.17 0.6 0.6 0.52 0.6 0.211 0.323

[0075] The multi-motor starter for the gate hoist test platform in this embodiment includes: a first resistance box, a second resistance box, and a third resistance box. The first resistance box includes three terminals for series connection with the motor rotor of a 320t or 250t hoist. The second resistance box includes three terminals for series connection with the motor rotor of a 160t-63t hoist. The third resistance box includes three terminals for series connection with the motor rotor of a 50t-25t hoist. Thus, using three resistance boxes covers motors of all hoist specifications, significantly reducing the number of resistance boxes, simplifying wiring and control complexity, and improving control reliability.

[0076] Furthermore, each of the first contactors, the second contactors, and the third contactors are connected to the processor for communication. Then, based on the specifications of the hoist being tested, the processor automatically selects the corresponding target resistor box and generates corresponding control commands to complete the starting process of the hoist's winch motor according to the control commands, thereby automating the starting of the hoist's winch motor.

[0077] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0078] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the invention.

Claims

1. A multi-motor starter for a gate hoist test platform, characterized in that, Comprise: The first resistance box, the second resistance box and the third resistance box; wherein, the first resistance box comprises three terminals, for being connected in series with the motor rotor of the 320t or 250t specification winch; the second resistance box comprises three terminals, for being connected in series with the motor rotor of the 160t-63t specification first winch; the third resistance box comprises three terminals, for being connected in series with the motor rotor of the 50t-25t specification first winch; The first resistance box comprises six groups of first resistance modules with preset resistance values, and the six groups of first resistance modules are connected in series according to a preset rule, and each first resistance module is connected with a first contactor in parallel; The second resistance box comprises six groups of second resistance modules with preset resistance values, and the six groups of second resistance modules are connected in series according to a preset rule, and each second resistance module is connected with a second contactor in parallel; The third resistance box comprises five groups of third resistance modules with preset resistance values, and the five groups of third resistance modules are connected in series according to a preset rule, and each third resistance module is connected with a third contactor in parallel; Each first contactor, each second contactor and each third contactor are respectively connected with the processor in communication, and the processor is used to execute the following steps when running: S100, obtaining the target specification of the current test hoist; S200, according to the target specification, accessing the target resistance box matched with the current test hoist; S300, according to the target specification, generating the control instruction ZL corresponding to the current test hoist; S400, according to ZL, controlling the action of each contactor corresponding to the target resistance box to complete the starting process of the winch motor of the current test hoist.

2. The multi-motor starter for the gate opening and closing machine test platform according to claim 1, characterized in that, The multi-motor starter further comprises a fourth resistance box and a fifth resistance box; wherein, the fourth resistance box is the same as the second resistance box, and the fifth resistance box is the same as the third resistance box; the fourth resistance box is used for being connected in series with the motor rotor of the 160t-63t specification second winch; the fifth resistance box comprises three terminals, for being connected in series with the motor rotor of the 50t-25t specification second winch.

3. The multi-motor starter for the gate opening and closing machine test platform according to claim 1, characterized in that, The processor is further used to execute the following steps when running: S310, according to the target specification and the preset resistance switching contactor action truth table QT, determining the preset action information of each contactor corresponding to the target resistance box; QT comprises a plurality of rows and a plurality of columns, each row corresponds to a specification of the hoist, and each column corresponds to the action information of a contactor corresponding to different specifications of the hoist; S320, add the preset action information of each contactor corresponding to the target resistor box to the preset structure to obtain the control command ZL = (KM1, KM2, ..., KM) i (i = 1, 2, ..., 6), where KM i This refers to the preset action information of the i-th contactor corresponding to the target resistor box; KM i =(KM i，1 KM i，2 KM i，3 ); KM i，1 For information regarding whether the i-th contactor corresponding to the target resistor box has operated and whether it has operated prematurely, KM i，2 For the action sequence information of the i-th contactor corresponding to the target resistor box, KM i，3 The time interval between the action of the i-th contactor and the next contactor corresponding to the target resistor box.

4. The multi-motor starter for the gate opening and closing machine test platform according to claim 3, characterized in that, The processor is further used to execute the following steps when running: S410, traversing the KM i , if the KM i，1 is preset action information or early action information, the KM i corresponding contactor is determined as a target contactor to obtain a target contactor list A=(A1, A2, …, A j , …, A m ), j=1, 2, …, m; wherein A j is the jth target contactor determined, and m is the number of target contactors determined; S420, based on the chronological order of the actions of each target contactor in A, sort all target contactors in A to obtain a sorted list of target contactors B = (B1, B2, ..., B...). j B m ); where B j Let j be the target contactor obtained by sorting all target contactors in A; S430, according to the arrangement order of each target contactor in B and the action time interval of each target contactor and the next contactor, sequentially controlling each target contactor.

5. The multi-motor starter for the gate opening and closing machine test platform according to claim 4, characterized in that, B1 is a contactor that acts in advance, and the processor is further used to execute the following steps when running: S431, at a preset time before the start of the current test hoist, controlling B1 to be powered on to cut off the resistance module connected in parallel with B1; S432, at the start of the current test, control B2 is energized, the interval corresponding KM i，3 After that, control B3 is energized, until B m is energized to complete the switching control of each target contactor in B.

6. The multi-motor starter for the gate opening and closing machine test platform according to claim 5, characterized in that, KM i，3 ranging from 1 to 3 S.

7. The multi-motor starter for the hoist test platform of claim 1, wherein, The total resistance of the first resistance box is 1.003Ω, the total resistance of the second resistance box is 0.725Ω, and the total resistance of the third resistance box is 1.35Ω.

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