Large-scale synchronous motor starting system of blast furnace blower

Abstract

The utility model discloses a large-scale synchronous motor starting system of a blast furnace blower, and belongs to the technical field of blast furnace blowers. Wire inlet ends of a first vacuum circuit breaker and a second vacuum circuit breaker are connected to a three-section type power supply bus through cables, and a wire outlet end of the first vacuum circuit breaker is connected with a wire inlet end of a frequency converter; the leading-out terminal of the frequency converter is connected to the first starting bus; the wire outlet end of the second vacuum circuit breaker is connected with the wire inlet end of the frequency converter and is connected to the first starting bus through the wire outlet end of the frequency converter; the first starting bus is connected with the starting bus, and the starting bus is respectively connected to the three groups of fan main motors through the three groups of relays, so that the variable-frequency soft starting device can start the first fan main motor, the second fan main motor and the third fan main motor, and also can start the third fan main motor; the frequency conversion soft starting device can start the third fan main motor, and also can start the first fan main motor and the second fan main motor; the two sets of frequency conversion soft starting devices are standby for each other.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace blowers, and in particular relates to a large synchronous motor starting system for a blast furnace blower. Background Art

[0002] At present, the supporting facilities of the new three blast furnaces - electric blast station, see Figure 2 The station has three blowers under its jurisdiction. Blowers No. 8 and No. 9 are used to support the new third blast furnace, and blower No. 10 is used to support the fourth blast furnace.

[0003] The main motors of the No. 8 and No. 9 blowers are 32MW synchronous motors, and the blowers are AV80-15 full-stator adjustable axial compressors produced by Shaanxi Blower. The main motor of the No. 10 blower is a 23MW synchronous motor, and the blower is an AV71-15 full-stator adjustable axial compressor. The 32MW synchronous motor of the electric blower station uses a medium-voltage current type (SINAMICS GL150) variable frequency soft starter; the 23MW synchronous motor uses a medium-voltage voltage type (SINAMICS GH180) variable frequency soft starter.

[0004] GL150 is a current-type variable frequency soft start device, and GH180 is a voltage-type variable frequency soft start device. The two cannot serve as backup for each other. When GL150 fails, blowers No. 8 and No. 9 will not start; when GH180 fails, blower No. 10 will not start. Summary of the invention

[0005] In view of the above problems, the present invention proposes a large synchronous motor starting system for a blast furnace blower, and two sets of variable frequency soft starting devices are arranged, so that the GL150 variable frequency soft starting device can start the first fan main motor, the second fan main motor and the third fan main motor, and can also start the third fan main motor; the GH180 variable frequency soft starting device can not only start the third fan main motor, but also start the first fan main motor and the second fan main motor; the two sets of variable frequency soft starting devices are backed up for each other.

[0006] The disclosed embodiment provides a blast furnace blower large synchronous motor starting system, wherein the first vacuum circuit breaker and the second vacuum circuit breaker have their inlet terminals connected to a three-section power supply busbar via cables, wherein the first vacuum circuit breaker and the second vacuum circuit breaker have their inlet terminals connected by the same cable;

[0007] The outlet terminal of the first vacuum circuit breaker is connected to the inlet terminal of the first frequency converter, and is connected to the first starting busbar through the outlet terminal of the first frequency converter;

[0008] The outlet terminal of the second vacuum circuit breaker is connected to the inlet terminal of the second frequency converter, and is connected to the first starting bus through the outlet terminal of the second frequency converter;

[0009] The first starting bus is connected to a starting bus, and the starting bus is connected to three groups of fan main motors respectively through three groups of relays.

[0010] Preferably, the outgoing terminal of the first frequency converter is connected to the incoming terminal of the first intermediate circuit breaker, and the outgoing terminal of the first intermediate circuit breaker is connected to the first starting bus;

[0011] The outgoing terminal of the second frequency converter is connected to the incoming terminal of the second intermediate circuit breaker, and the outgoing terminal of the second intermediate circuit breaker is connected to the first starting bus.

[0012] Preferably, the first fan main motor is connected to the starting busbar via a first circuit breaker;

[0013] The second fan main motor is connected to the starting busbar through the second circuit breaker;

[0014] The third fan main motor is connected to the starting busbar through the third circuit breaker;

[0015] The frequency converter indirectly controls the power supply to the fan main motor through the starting bus and three sets of circuit breakers.

[0016] Preferably, the incoming line side of the second frequency converter is connected to a cable via a second vacuum circuit breaker, and the cable is connected to the third bus section via a sixth circuit breaker, thereby forming a power supply path for the third bus section;

[0017] The incoming line side of the first frequency converter is connected to the cable through the first vacuum circuit breaker, and the cable is connected to the first bus section through the fourth circuit breaker, forming a power supply path for the first bus section.

[0018] Preferably, the cable is also connected to the second bus section through a fifth circuit breaker to form a power supply path for the second bus section.

[0019] Preferably, the starting system further comprises:

[0020] An interface cabinet, used for providing an interface for the first frequency converter and the second frequency converter to connect the first fan main motor, the second fan main motor and the third fan main motor;

[0021] The interface cabinet communicates with two groups of frequency converters, the first frequency converter and the second frequency converter, via a DP communication network.

[0022] Preferably, the starting system further comprises:

[0023] The synchronization device is used to adjust the voltage, frequency and phase on both sides of the variable frequency soft starter to be consistent, and send a closing signal to the bypass circuit breaker.

[0024] At the same time, the excitation cabinet sends a tripping signal to disconnect the first circuit breaker, the second circuit breaker, the third circuit breaker, the first intermediate circuit breaker and the second intermediate circuit breaker.

[0025] Preferably, the synchronization device includes a first synchronization device, a second synchronization device and a third synchronization device;

[0026] The first synchronization device is used for the first frequency converter to start the first fan main motor, and the second synchronization device is used for the frequency converter to start the second fan main motor;

[0027] The third synchronization device is used for the first frequency converter to start the third fan main motor.

[0028] Preferably, a sixth intermediate relay, a seventh intermediate relay and an eighth intermediate relay are provided in the interface cabinet;

[0029] The sixth intermediate relay short-circuits the output relay of the first synchronization device;

[0030] The seventh intermediate relay short-circuits the output relay of the second synchronization device;

[0031] The eighth intermediate relay short-circuits the output relay of the third synchronization device.

[0032] Preferably, when the second frequency converter starts the first fan main motor, the second fan main motor and the third fan main motor,

[0033] The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are short-circuited;

[0034] When the first inverter starts the first fan main motor, the second fan main motor and the third fan main motor,

[0035] The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are de-energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are operated.

[0036] Beneficial effects of the present disclosure: In the present application, the incoming terminals of the first vacuum circuit breaker and the second vacuum circuit breaker are connected to the three-stage power supply bus through cables, the outgoing terminal of the first vacuum circuit breaker is connected to the incoming terminal of the first frequency converter, and is connected to the first starting bus through the outgoing terminal of the first frequency converter; the outgoing terminal of the second vacuum circuit breaker is connected to the incoming terminal of the frequency converter, and is connected to the first starting bus through the outgoing terminal of the frequency converter; the first starting bus is connected to the starting bus, and the starting bus is respectively connected to three groups of fan main motors through three groups of relays, so that the variable frequency soft starting device can start the first fan main motor, the second fan main motor and the third fan main motor, and can also start the third fan main motor; the variable frequency soft starting device can not only start the third fan main motor, but also start the first fan main motor and the second fan main motor; the two sets of variable frequency soft starting devices are backed up for each other.

[0037] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures indicated in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A schematic diagram of a primary circuit of a large synchronous motor starting system for a blast furnace blower disclosed in the present invention is shown;

[0040] Figure 2 The primary control principle diagram of the blower supporting the new third blast furnace in the background technology is shown;

[0041] Figure 3 A secondary control schematic diagram of a large synchronous motor starting system for a blast furnace blower disclosed in the present invention is shown. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0043] It should be noted that the terms "first", "second", etc. in the present disclosure are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present disclosure described herein. In the present disclosure, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings.

[0044] The present disclosure provides a large synchronous motor starting system for a blast furnace blower. Figure 1 , the incoming terminals of the first vacuum circuit breaker MBC01 and the second vacuum circuit breaker MBC02 are connected to the three-section power supply busbar through cables, wherein the incoming terminals of the first vacuum circuit breaker MBC01 and the second vacuum circuit breaker MBC02 are connected by the same cable;

[0045] The outlet terminal of the first vacuum circuit breaker MBC01 is connected to the inlet terminal of the first frequency converter GL150, and is connected to the first starting bus through the outlet terminal of the first frequency converter GL150;

[0046] The outlet terminal of the second vacuum circuit breaker MBC02 is connected to the inlet terminal of the frequency converter GH180, and is connected to the first starting bus through the outlet terminal of the frequency converter GH180;

[0047] The first starting bus is connected to a starting bus, and the starting bus is connected to three groups of fan main motors respectively through three groups of relays.

[0048] It should be noted that the technical solutions involved in the present disclosure are mainly aimed at the blast furnace supporting facilities - electric blower station. The first blower main motor, the second blower main motor and the third blower main motor referred to in the present disclosure refer to the No. 8, No. 9 and No. 10 blowers in this disclosure specification, among which No. 8 and No. 9 are the blowers supporting the new third blast furnace, and No. 10 blower is the blower supporting the fourth blast furnace.

[0049] In order to ensure the reliability and stability of the wind turbines, two sets of variable frequency soft-start devices are designed, so that the GL150 variable frequency soft-start device can start fans No. 8 and No. 9, that is, start the first main wind turbine and the second main wind motor, and start fan No. 10, that is, the third main wind motor; the GH180 variable frequency soft-start device can not only start fan No. 10, but also start fans No. 8 and No. 9, so that the two sets of variable frequency soft-start devices can serve as backup for each other.

[0050] Specifically, the outgoing terminal of the first frequency converter GL150 is connected to the incoming terminal of the first intermediate circuit breaker MBM01, and the outgoing terminal of the first intermediate circuit breaker MBM01 is connected to the first starting bus;

[0051] The outgoing terminal of the second frequency converter GH180 is connected to the incoming terminal of the second intermediate circuit breaker MBM02, and the outgoing terminal of the second intermediate circuit breaker MBM02 is connected to the first starting bus.

[0052] The first fan main motor is connected to the starting busbar through the first circuit breaker MBM1;

[0053] The second fan main motor is connected to the starting busbar through the second circuit breaker MBM2;

[0054] The third fan main motor is connected to the starting busbar through the third circuit breaker MBM3;

[0055] The frequency converter indirectly controls the power supply to the fan main motor through the starting bus and three sets of circuit breakers.

[0056] In some embodiments, the incoming line side of the second frequency converter GH180 is connected to a cable through the second vacuum circuit breaker MBC02, and the cable is connected to the third bus section through the sixth circuit breaker MBC3, forming a power supply path for the third bus section;

[0057] The incoming line side of the first frequency converter GL150 is connected to the cable through the first vacuum circuit breaker MBC01, and the cable is connected to the first bus section through the fourth circuit breaker MBC1, forming a power supply path for the first bus section.

[0058] The cable is also connected to the second bus section through the fifth circuit breaker MBC2, forming a power supply path for the second bus section.

[0059] Combine the following Figure 1 The primary circuit of the present application is described in detail.

[0060] See also Figure 1 The isolation cabinet (with voltage transformer) for the incoming line of the first inverter GL150 is equipped with a vacuum circuit breaker MBC01 (with voltage transformer). The lower ends of the vacuum circuit breakers MBC1 and MBC2 are connected to the lower end of the circuit breaker MBC01 through cables. The circuit breaker MBC01 is connected to the primary side of the first inverter GL150 step-down transformer through a copper busbar.

[0061] A vacuum circuit breaker MBM01 is set to be connected to the outgoing terminal of the first frequency converter GL150 and the outgoing busbar collection cabinet of the first frequency converter GL150. The secondary side of the first frequency converter GL150 step-up transformer is connected to the lower end of the outgoing circuit breaker MBM01 of the first frequency converter GL150 through a cable, the upper end of the outgoing circuit breaker MBM01 of the first frequency converter GL150 is connected to the upper end of the outgoing busbar collection cabinet of the first frequency converter GL150 through a copper busbar, and the lower end of the outgoing busbar collection cabinet of the first frequency converter GL150 is connected to the lower end of the outgoing isolation cabinet of the first frequency converter GL150 through a cable.

[0062] Two vacuum circuit breakers are provided, one for the circuit breaker MBC02 on the incoming line side of the second frequency converter GH180, and the other for the circuit breaker MBM02 on the outgoing line side of the second frequency converter GH180.

[0063] The upper end of the circuit breaker MBC3 is connected to the 10KVIII bus. The lower end of the circuit breaker MBC3 is connected to the lower end of the incoming busbar collection cabinet of the first inverter GL150 through a cable. The lower end of the circuit breaker MBC3 is then connected to the lower end of the incoming side circuit breaker MBC02 of the second inverter GH180 through a copper busbar. The upper end of the upper end of the circuit breaker MBC02 on the incoming side of the second inverter GH180 is connected to the upper end of the busbar collection cabinet (the incoming side of the second inverter GH180) through a copper busbar. The upper end of the intermediate circuit breaker MBM02 on the outgoing side of the second inverter GH180 is connected to the upper end of the busbar collection cabinet (the incoming and outgoing side of the second inverter GH180) through a copper busbar, and the lower end of the busbar collection cabinet is connected to the lower end of the outgoing busbar collection cabinet of the first inverter GL150 through a cable. The lower end of the intermediate circuit breaker MBM3 is connected to the lower end of the bypass circuit breaker MBL3 through a cable.

[0064] In some embodiments, the interface cabinet MMIP is used to provide an interface for the first frequency converter GL150 and the second frequency converter GH180 to connect the first fan main motor, the second fan main motor and the third fan main motor;

[0065] The interface cabinet communicates with the first inverter GL150 and the second inverter GH180 via a DP communication network.

[0066] Specifically, when the first inverter GL150 is selected to start the unit, the input circuit breaker MBC01 and the output intermediate circuit breaker MBM01 of the first inverter GL150 are moved to the working position and closed, the first inverter GL150 is started, and the DP communication network from the interface cabinet to the first inverter GL150 is established. The communication from the interface cabinet to the excitation cabinet MMCP is established by the starting unit sending a "request to start".

[0067] When the second inverter GH180 is selected to start the unit, the input circuit breaker MBC02 and the output intermediate circuit breaker MBM02 of the second inverter GH180 are moved to the working position and closed, and the second inverter GH180 is started. The DP communication network from the interface cabinet to the second inverter GH180 is established. The communication from the interface cabinet to the excitation cabinet MMCP is established by the starting unit sending a "request to start".

[0068] In some embodiments, the startup system further comprises:

[0069] The synchronization device is used to adjust the voltage, frequency and phase on both sides of the variable frequency soft starter to be consistent, and send a closing signal to the bypass circuit breaker MBL.

[0070] At the same time, the excitation cabinet EXC sends a tripping signal to disconnect the first circuit breaker, the second circuit breaker, the third circuit breaker, the first intermediate circuit breaker and the second intermediate circuit breaker.

[0071] The synchronization device comprises a first synchronization device, a second synchronization device and a third synchronization device;

[0072] The first synchronization device is used for the first frequency converter GL150 to start the first fan main motor, and the second synchronization device is used for the first frequency converter GL150 to start the second fan main motor;

[0073] The third synchronization device is used for the first frequency converter GL150 to start the third fan main motor.

[0074] The interface cabinet MMIP is provided with a sixth intermediate relay, a seventh intermediate relay and an eighth intermediate relay;

[0075] The sixth intermediate relay short-circuits the output relay of the first synchronization device;

[0076] The seventh intermediate relay short-circuits the output relay of the second synchronization device;

[0077] The eighth intermediate relay short-circuits the output relay of the third synchronization device.

[0078] When the GH180 frequency converter starts the first fan main motor, the second fan main motor and the third fan main motor,

[0079] The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are short-circuited;

[0080] When the GL150 frequency converter starts the first fan main motor, the second fan main motor and the third fan main motor,

[0081] The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are de-energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are operated.

[0082] Combine the following Figure 3 The secondary control of the present disclosure will be described in detail.

[0083] The present disclosure uses an interface cabinet MMIP to coordinate and control the interface functions of the first frequency converter GL150 and the second frequency converter GH180 to start the No. 8, No. 9, and No. 10 fans. That is, the interface cabinet MMIP controls the start of the first fan main motor, the second fan main motor, and the third fan main motor.

[0084] It should be noted that the synchronization device used in the present disclosure includes a first synchronization device, a second synchronization device and a third synchronization device. The synchronization device is an indication, monitoring and control device used when performing grid connection during the operation of the power system. It can detect whether the grid frequency, voltage amplitude and voltage phase on both sides of the grid connection point meet the grid connection conditions to assist manual grid connection or realize automatic grid connection.

[0085] The first inverter GL150 is selected to start the fan. When the speed of the fan main motor reaches the rated speed (1500r / min), the second inverter GH180 is shut down by closing the bypass circuit breaker MBL. When closing the bypass circuit breaker MBL, it is necessary to synchronize the two sides of the variable frequency soft starter (grid side and motor side). The synchronization device adjusts the voltage, frequency and phase on both sides of the variable frequency soft starter to be consistent, and sends a closing signal to the bypass circuit breaker MBL. At the same time, the excitation cabinet (EXC) sends a tripping signal to disconnect the relay MBC and the intermediate circuit breaker MBM.

[0086] The second inverter GH180 is selected to start the fan. When the speed of the fan main motor reaches the rated speed (1500r / min), the first inverter GL150 is shut down by closing the bypass circuit breaker MBL. When closing the bypass circuit breaker MBL, there is no need to synchronize the two sides of the variable frequency soft starter (grid side and motor side).

[0087] A synchronization device (7VE61) is set on the interface cabinet (MMIP) for the first inverter GL150 to start fan No. 10. The original synchronization device is used when the first inverter GL150 starts fans No. 8 and No. 9.

[0088] See also Figure 3 , add three intermediate relays -K360.6, -K370.6, -K380.6 to the interface cabinet (MMIP), which are used to short-circuit the synchronization devices of fans No. 8, No. 9, and No. 10 respectively. Relay -K360.6 short-circuits the synchronization device output relay -K85 of the excitation cabinet EXC NO.8, relay -K370.6 short-circuits the synchronization device output relay -K85 of the excitation cabinet EXC NO.9, and relay -K380.6 short-circuits the synchronization device output relay -K40 of the excitation cabinet EXC NO.10. Figure 3 When the first inverter GL150 is selected to start fans No. 8, 9, and 10, relays -K360.6, -K370.6, and -K380.6 are not energized, the normally open node is opened, and the synchronous device output relays -K85 and -K40 work. When the second inverter GH180 is selected to start fans No. 8, 9, and 10, relays -K360.6, -K370.6, and -K380.6 are energized and work, the normally open node is closed, and the synchronous device output relays -K85 and -K40 are short-circuited.

[0089] The No. 8 and No. 9 fans of the electric blast station disclosed in the present invention adopt a 1-to-2 starting method to supply air to the new No. 3 blast furnace, and the No. 10 fan adopts a 1-to-1 starting method to supply air to the No. 4 blast furnace. The two frequency converters cannot serve as backup for each other. If one of the frequency converters fails, it will affect the stability of blast furnace production. In order to ensure the reliability and stability of the fans, the two sets of variable frequency soft start devices are improved so that the first frequency converter GL150 soft start device can start both No. 8 and No. 9 fans and No. 10 fans; the second frequency converter GH180 soft start device can not only start No. 10 fans, but also No. 8 and No. 9 fans, so that the two sets of variable frequency soft start devices can serve as backup for each other.

[0090] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A large synchronous motor starting system for a blast furnace blower, characterized in that: The incoming line terminals of the first vacuum circuit breaker (MBC01) and the second vacuum circuit breaker (MBC02) are connected to the three-section power supply busbar through cables, wherein the incoming line terminals of the first vacuum circuit breaker (MBC01) and the second vacuum circuit breaker (MBC02) are connected by the same cable; The outlet terminal of the first vacuum circuit breaker (MBC01) is connected to the inlet terminal of the first frequency converter (GL150), and is connected to the first starting bus through the outlet terminal of the first frequency converter (GL150); The outlet terminal of the second vacuum circuit breaker (MBC02) is connected to the inlet terminal of the second frequency converter (GH180), and is connected to the first starting bus through the outlet terminal of the second frequency converter (GH180); The first starting bus is connected to a starting bus, and the starting bus is connected to three groups of fan main motors respectively through three groups of relays.

2. The starting system according to claim 1, characterized in that: The outgoing terminal of the first frequency converter (GL150) is connected to the incoming terminal of the first intermediate circuit breaker (MBM01), and the outgoing terminal of the first intermediate circuit breaker (MBM01) is connected to the first starting bus; The outgoing terminal of the second frequency converter (GH180) is connected to the incoming terminal of the second intermediate circuit breaker (MBM02), and the outgoing terminal of the second intermediate circuit breaker (MBM02) is connected to the first starting bus.

3. The starting system according to claim 1, characterized in that: The first fan main motor is connected to the starting busbar through the first circuit breaker (MBM1); The second fan main motor is connected to the starting busbar through the second circuit breaker (MBM2); The third fan main motor is connected to the starting busbar through the third circuit breaker (MBM3); The frequency converter indirectly controls the power supply to the fan main motor through the starting bus and three sets of circuit breakers.

4. The starting system according to claim 1, characterized in that: The incoming line side of the second frequency converter (GH180) is connected to a cable through the second vacuum circuit breaker (MBC02), and the cable is connected to the third bus section through the sixth circuit breaker (MBC3), forming a power supply path for the third bus section; The incoming line side of the first frequency converter (GL150) is connected to a cable via a first vacuum circuit breaker (MBC01), and the cable is connected to the first bus section via a fourth circuit breaker (MBC1), thereby forming a power supply path for the first bus section.

5. The starting system according to claim 4, characterized in that: The cable bus is also connected to the second bus section through a fifth circuit breaker (MBC2), forming a power supply path for the second bus section.

6. The starting system according to claim 1, characterized in that: The startup system also includes: An interface cabinet (MMIP) is used to provide an interface for the first frequency converter (GL150) and the second frequency converter (GH180) to connect the first fan main motor, the second fan main motor and the third fan main motor; The interface cabinet communicates with two groups of frequency converters, namely, the first frequency converter (GL150) and the second frequency converter (GH180) via a DP communication network.

7. The starting system according to claim 6, characterized in that: The startup system also includes: The synchronization device is used to adjust the voltage, frequency and phase on both sides of the variable frequency soft starter to be consistent, and send a closing signal to the bypass circuit breaker (MBL). At the same time, the excitation cabinet (EXC) sends a trip signal to disconnect the first circuit breaker, the second circuit breaker, the third circuit breaker, the first intermediate circuit breaker and the second intermediate circuit breaker.

8. The starting system according to claim 7, characterized in that: The synchronization device comprises a first synchronization device, a second synchronization device and a third synchronization device; The first synchronization device is used for the first frequency converter (GL150) to start the first fan main motor, and the second synchronization device is used for the first frequency converter (GL150) to start the second fan main motor; The third synchronization device is used for the first frequency converter (GL150) to start the third fan main motor.

9. The starting system according to claim 6, characterized in that: The interface cabinet (MMIP) is provided with a sixth intermediate relay, a seventh intermediate relay and an eighth intermediate relay; The sixth intermediate relay short-circuits the output relay of the first synchronization device; The seventh intermediate relay short-circuits the output relay of the second synchronization device; The eighth intermediate relay short-circuits the output relay of the third synchronization device.

10. The starting system according to claim 9, characterized in that: When the second inverter (GH180) starts the first fan main motor, the second fan main motor and the third fan main motor, The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are short-circuited; When the first inverter (GL150) starts the first fan main motor, the second fan main motor and the third fan main motor, The sixth intermediate relay, the seventh intermediate relay and the eighth intermediate relay are de-energized, and the output relay of the first synchronization device, the output relay of the second synchronization device and the output relay of the third synchronization device are operated.

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