A redundant frequency conversion drive system for an ultra-large casting crane

Abstract

This invention provides a redundant variable frequency drive system for an ultra-large casting crane, comprising: a rectifier feedback system, a main hoisting drive system, an auxiliary hoisting drive system, a main trolley drive system, an auxiliary trolley drive system, and a trolley drive system. Each system operates independently, driving its corresponding mechanism. This system features fault emergency switching and long-term normal operation, offering more comprehensive redundancy coverage, higher drive system reliability, avoiding equipment downtime, and ensuring continuous production. In this system, the capacity of the main hoisting motor, main hoisting inverter, and rectifier feedback unit can all be reduced by 30%, significantly lowering equipment costs and making the electrical control system more energy-efficient. The main hoisting mechanism adopts a staggered starting method, reducing the starting current by 25% and greatly minimizing the impact on the power grid.

Description

Technical Field

[0001] This invention relates to the field of variable frequency drive system technology, and more particularly to a redundant variable frequency drive system for an ultra-large casting crane. Background Technology

[0002] With the national elimination of outdated production capacity and the promotion of green, low-carbon, and high-quality development in the steel industry, the demand for the lifting capacity of casting cranes is constantly increasing. The market demand for ultra-large casting cranes of 500 tons and above is showing an increasing trend, and the requirements for crane models are shifting from single-type to diversified. Furthermore, casting cranes operate in harsh environments with high working levels; they handle molten metal, requiring high safety performance. Therefore, casting cranes must have mature and reliable drive systems with redundancy and backup functions to meet the needs of long-term normal operation.

[0003] Currently, although some casting cranes have incorporated fault emergency switching designs (such as...) Figure 1 (As shown), however, this approach only enables short-term emergency use of the mechanism and cannot meet the requirements for long-term normal operation. The scheme employing "emergency switching drive of the auxiliary hoisting motor by the main trolley inverter" and "emergency switching drive of the auxiliary trolley motor by the main trolley inverter" suffers from drawbacks such as mutual interference between the drive systems of each mechanism, limited redundancy coverage, complex switching circuits, high failure rate, and poor practicality. Furthermore, only the emergency operation of the main hoisting mechanism with a large reducer was studied, without considering the redundancy design of planetary reducer models. Summary of the Invention

[0004] In view of the technical problems mentioned in the background section, this invention provides a redundant frequency converter drive system for an ultra-large casting crane. This invention provides a redundant frequency converter drive system for an ultra-large casting crane (such as...) Figure 2 As shown, this system comprises a rectifier feedback system, a main hoisting drive system, an auxiliary hoisting drive system, a main trolley drive system, an auxiliary trolley drive system, and a trolley drive system. It is a complete, online redundant frequency converter drive system that enables emergency switching during faults and long-term normal operation of the casting crane. Furthermore, a redundant design for the planetary reducer of the main hoisting mechanism for ultra-large casting cranes has been developed. This improves the practicality and reliability of the electrical control system, avoids equipment downtime due to failure, and ensures enterprise production efficiency.

[0005] The technical means employed in this invention are as follows:

[0006] A redundant frequency converter drive system for an ultra-large casting crane includes:

[0007] The rectifier feedback system, main lifting drive system, auxiliary lifting drive system, main trolley drive system, auxiliary trolley drive system and trolley drive system each work independently and drive the corresponding mechanism to operate.

[0008] The rectifier feedback system provides power and regenerative energy feedback to all drive systems. The rectifier feedback system includes a first rectifier feedback system and a second rectifier feedback system. The first and second rectifier feedback systems have identical configurations. Under normal circumstances, the first and second rectifier feedback systems operate independently. When one system fails, the other system supplies power to all drive systems to ensure continued operation of the equipment.

[0009] The main lifting drive system, auxiliary lifting drive system, main trolley drive system, auxiliary trolley drive system, and trolley drive system operate independently, each driving the corresponding mechanism.

[0010] Furthermore, the first set of rectification feedback system includes: rectification feedback unit U11, incoming line circuit breaker Q11, and outputting the first common DC bus after passing through disconnecting switch Q01; the main hoisting first set of drive system, auxiliary hoisting drive system, main trolley first set and trolley first set of drive system are connected to the first common DC bus through their respective DC disconnecting switches to obtain power supply;

[0011] The second set of rectification feedback system includes: rectification feedback unit U12, incoming circuit breaker Q12, and outputting a second common DC bus after passing through disconnecting switch Q02; the main hoisting second set of drive system, auxiliary trolley drive system, main trolley second set of drive system and trolley second set of drive system are connected to the second common DC bus through their respective DC disconnecting switches to obtain power supply.

[0012] Furthermore, the rectification feedback system is an active adjustment type rectification unit, and the capacity of each rectification unit can meet the simultaneous normal operation of both the main hoisting and the trolley mechanisms.

[0013] Furthermore, the main hoisting mechanism adopts a planetary reducer model; the main hoisting drive system includes: a first drive system and a second drive system, the two systems are completely identical in configuration and jointly drive the main hoisting planetary reducer;

[0014] The first drive system includes: inverter U21, inverter U22, and inverter U23 drive motor M21 and motor M22; the input terminals of the three inverters are connected to the first common DC bus via isolating switches Q21, Q22, and Q23, and the output terminals of the inverters are connected to the two motors via switching switches Q211, Q221, and Q231; when inverter U21 or inverter U22 fails, it switches to the backup inverter U23 to ensure the normal operation of the main hoisting mechanism;

[0015] The second drive system includes: inverter U24, inverter U25, and inverter U26 drive motors M23 and M24; the input terminals of the three inverters are connected to the second common DC bus via isolating switches Q24, Q25, and Q26, and the output terminals of the three inverters are connected to the two motors via switching switches Q241, Q251, and Q261; when inverter U24 or inverter U25 fails, it switches to the backup inverter U26 to ensure the normal operation of the main hoisting mechanism.

[0016] Furthermore, the main hoisting drive system adopts a staggered start-up method, starting one set of motors first, and then starting another set of motors when the motors reach their rated speed.

[0017] Furthermore, the auxiliary lifting drive system includes: inverter U31 and inverter U32 driving motor M31; the input terminals of the two inverters are connected to the first common DC bus via isolating switches Q31 and Q32, and the output terminals of the two inverters are connected to the motor via switching switch Q33; during normal operation, it is driven by one inverter; when this inverter fails, it switches to the other inverter to ensure that the mechanism can continue to work normally.

[0018] Furthermore, the main vehicle drive system includes: a first drive system and a second drive system;

[0019] The first drive system includes: an inverter U41 driving motors M41 and M42; the input terminal of the inverter is connected to the first common DC bus via an isolating switch Q41, and the output terminal of the inverter is connected to the two motors via motor circuit breakers Q411 and Q412.

[0020] The second drive system includes: inverter U42 driving motors M43 and M44; the input terminal of the inverter is connected to the second common DC bus via isolating switch Q42, and the output terminal of the inverter is connected to the two motors via motor circuit breaker Q421 and motor circuit breaker Q422.

[0021] The capacity of each inverter is sufficient for the normal operation of the mechanism. Under normal circumstances, both inverters are used simultaneously; when one inverter fails, the other inverter drives the entire mechanism to continue operating.

[0022] Furthermore, the auxiliary trolley drive system includes: inverter U51 and inverter U52 driving motor M51; the input terminals of the two inverters are connected to the second common DC bus via isolating switches Q51 and Q52, and the output terminals of the two inverters are connected to the motor via switching switch Q53; during normal operation, it is driven by one inverter; when this inverter fails, it switches to the other inverter to ensure that the mechanism can continue to work normally.

[0023] Furthermore, the vehicle drive system includes: a first drive system and a second drive system;

[0024] The first drive system includes: an inverter U61 driving motors M61 and M62; the input terminal of the inverter is connected to the first common DC bus via an isolating switch Q61, and the output terminal of the inverter is connected to the two motors via motor circuit breakers Q611 and Q612.

[0025] The second drive system includes: inverter U62 driving motors M63 and M64; the input terminal of the inverter is connected to the second common DC bus via isolating switch Q62, and the output terminal of the inverter is connected to the two motors via motor circuit breaker Q621 and motor circuit breaker Q622;

[0026] The capacity of each inverter is sufficient for the normal operation of the mechanism. Under normal circumstances, both inverters are used simultaneously; when one inverter fails, the other inverter drives the entire mechanism to continue operating normally.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The system of this invention features emergency switching during faults and long-term normal operation, with more comprehensive redundancy coverage, higher reliability of the drive system, avoidance of equipment failure downtime, and guarantee of production continuity.

[0029] In this invention system, the capacity of the main hoisting motor, main hoisting inverter, and rectifier unit can all be reduced by 30%, significantly lowering equipment costs and making the electrical control system more energy-efficient. The main hoisting mechanism adopts a staggered starting method, reducing the starting current by 25% and greatly minimizing the impact on the power grid. Both the main trolley and the crane mechanism have two inverters. Under normal circumstances, both inverters operate simultaneously; when one inverter fails, the other inverter drives the mechanism to continue normal operation, improving the system's practicality.

[0030] In this invention, both the auxiliary lifting and auxiliary trolley mechanisms have one working inverter and one backup inverter. This redundancy scheme is reliable, has a low failure rate, and avoids the impact of a failure in one mechanism on other mechanisms, thus improving system reliability. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a diagram of the fault redundancy system for the frequency converter speed control of an existing casting crane.

[0033] Figure 2 This is a diagram of a redundant frequency conversion drive system for an ultra-large casting crane according to the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] like Figure 2 As shown, the present invention provides a redundant frequency conversion drive system for an ultra-large casting crane, comprising a rectifier feedback system, a main hoisting drive system, an auxiliary hoisting drive system, a main trolley drive system, an auxiliary trolley drive system, and a trolley drive system.

[0037] The rectifier feedback system consists of a first rectifier feedback system 1-1 and a second rectifier feedback system 1-2. The first rectifier feedback system includes a rectifier feedback unit U11 and an incoming circuit breaker Q11. After passing through the disconnecting switch Q01, it outputs a first common DC bus to provide DC power to the main hoisting first drive system 2-1, the auxiliary hoisting drive system 3, the main trolley first drive system 4-1, and the trolley first drive system 6-1. The second rectifier feedback system includes a rectifier feedback unit U12 and an incoming circuit breaker Q12. After passing through the disconnecting switch Q02, it outputs a second common DC bus to provide DC power to the main hoisting second drive system 2-2, the auxiliary trolley drive system 5, the main trolley second drive system 4-2, and the trolley second drive system 6-2. The rectifier feedback system provides power and regenerative energy feedback to all drive systems. The rectifier feedback system includes a first rectifier feedback system and a second rectifier feedback system. The first rectifier feedback system and the second rectifier feedback system have identical configurations. Under normal circumstances, the first rectifier feedback system and the second rectifier feedback system work independently. When one of the systems fails, the other system supplies power to all drive systems to ensure the equipment continues to operate.

[0038] The rectifier feedback device should use an actively adjustable rectifier unit, with the capacity of each unit sufficient to support the simultaneous normal operation of both the main hoisting and trolley mechanisms. Under normal circumstances, both rectifier feedback units operate simultaneously. When one rectifier unit fails, it is disconnected, and the busbar connection switch Q03 is closed, allowing the other rectifier unit to simultaneously supply power to both common DC buses, ensuring the crane continues to operate normally and achieving redundancy backup.

[0039] For main hoisting mechanisms using large reducers, the fault redundancy protection system and redundancy protection method for frequency conversion speed regulation of casting cranes (patent number: CN102167260B) have been studied in detail and will not be repeated here. This invention mainly focuses on the research of main hoisting mechanisms of ultra-large casting cranes using planetary reducers.

[0040] The main hoisting mechanism uses four electric motors, but its drive system can be configured with two inverters, four inverters, or no backup inverters, etc., but these modifications do not deviate from the scope of the technical solution of this invention. This embodiment preferably uses four working inverters and two backup inverters as an example to describe the technical solution of the redundant drive system for the main hoisting mechanism.

[0041] The main hoisting drive system consists of a first drive system 2-1 and a second drive system 2-2. The first drive system includes two working inverters U21 and U22, one standby inverter U23, isolating switches Q21, Q22, and Q23, and switching switches Q211, Q221, and Q231, used to drive motors M21 and M22. When one of the working inverters fails, it switches to the standby inverter to ensure the normal operation of the main hoisting mechanism. The second drive system includes two working inverters U24 and U25, one standby inverter U26, isolating switches Q24, Q25, and Q26, and switching switches Q241, Q251, and Q261, used to drive motors M23 and M24, and also has a redundancy switching function.

[0042] The main hoisting mechanism adopts a planetary reducer model; the main hoisting drive system includes: a first drive system and a second drive system, the two systems are completely identical in configuration and jointly drive the main hoisting planetary reducer.

[0043] The first drive system includes: inverter U21, inverter U22, and inverter U23 drive motor M21 and motor M22; the input terminals of the three inverters are connected to the first common DC bus via isolating switches Q21, Q22, and Q23, and the output terminals of the inverters are connected to the two motors via switching switches Q211, Q221, and Q231; when inverter U21 or inverter U22 fails, it switches to the backup inverter U23 to ensure the normal operation of the main hoisting mechanism;

[0044] The second drive system includes: inverter U24, inverter U25, and inverter U26 drive motors M23 and M24; the input terminals of the three inverters are connected to the second common DC bus via isolating switches Q24, Q25, and Q26, and the output terminals of the three inverters are connected to the two motors via switching switches Q241, Q251, and Q261; when inverter U24 or inverter U25 fails, it switches to the backup inverter U26 to ensure the normal operation of the main hoisting mechanism.

[0045] The main hoisting drive system adopts a staggered start method, starting one set of motors first, and then starting another set of motors when the motors reach their rated speed.

[0046] In addition to maintaining the inherent single-machine, half-speed, full-load, and long-term operation characteristics of planetary reducers, this technical solution equips each of the four motors with an independent inverter. When one working inverter fails, it can quickly switch to the backup inverter, ensuring the mechanism operates normally at full load and speed. The redundant backup protection range is more comprehensive, greatly improving the reliability of the drive system, avoiding equipment failure downtime, and ensuring the continuity of production operations.

[0047] Compared to models with large gearboxes, the capacity of the main hoisting motor, main hoisting inverter, and rectifier unit can all be reduced by 30%, resulting in a significant reduction in equipment costs and a more energy-efficient electrical control system. Furthermore, the staggered starting method, which starts one set of motors first and then starts the other set once they reach their rated speed, reduces the starting current by 25%, greatly minimizing the impact on the power grid.

[0048] Furthermore, planetary reducers have two degrees of freedom, requiring real-time monitoring of the entire transmission chain (see Chinese patent applications CN200510078243 and CN201410698220). A safety brake is installed on the drum. Also, because planetary reducers operate at high speeds, the bearings are prone to overheating, necessitating the design of an external circulating cooling system for the lubricating oil.

[0049] The auxiliary lifting drive system 2 consists of a working inverter U31, a standby inverter U32, isolating switches Q31 and Q32, and a switching switch Q33, used to drive the motor M31. When the working inverter fails, it can quickly switch to the standby inverter. Compared with the existing "emergency switching of the main trolley inverter to drive the auxiliary lifting motor" scheme, the redundant backup scheme is reliable, has a low failure rate, and avoids the impact on the trolley mechanism due to a failure of the auxiliary lifting inverter. The auxiliary lifting drive system includes: inverters U31 and U32 driving one motor M31; the input terminals of the two inverters are connected to the first common DC bus via isolating switches Q31 and Q32, and the output terminals of the two inverters are connected to the motor via switching switch Q33; during normal operation, one inverter drives the motor; when this inverter fails, it switches to the other inverter to ensure the mechanism can continue to operate normally.

[0050] The main trolley drive system consists of a first drive system 4-1 and a second drive system 4-2. The first drive system comprises an inverter U41, a disconnect switch Q41, and motor circuit breakers Q411 and Q412, used to drive motors M41 and M42. The second drive system comprises an inverter U42, a disconnect switch Q42, and motor circuit breakers Q421 and Q422, used to drive motors M43 and M44. The capacity of each inverter is sufficient for the normal operation of the mechanism. Under normal circumstances, both inverters operate simultaneously; when one inverter fails, the other inverter drives the entire mechanism to continue normal operation.

[0051] The auxiliary trolley drive system 5 consists of a working inverter U51, a standby inverter U52, isolating switches Q51 and Q52, and a switching switch Q53, used to drive the motor M51. When the working inverter fails, it can quickly switch to the standby inverter. Compared with the existing "main trolley inverter emergency switching to drive the auxiliary trolley motor" solution, it is more reliable, has a lower failure rate, and is independently configured with the main trolley mechanism, without affecting each other.

[0052] The trolley drive system consists of a first drive system 6-1 and a second drive system 6-2. The first drive system comprises an inverter U61, a disconnect switch Q61, and motor circuit breakers Q611 and Q612, used to drive motors M61 and M62. The second drive system comprises an inverter U62, a disconnect switch Q62, and motor circuit breakers Q621 and Q462, used to drive motors M63 and M64. The capacity of each inverter is sufficient for the normal operation of the mechanism. Under normal circumstances, both inverters are used simultaneously; when one inverter fails, the other inverter drives the trolley mechanism to continue operating normally, ensuring production continuity.

[0053] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0054] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0055] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0056] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0057] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0058] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A redundant frequency conversion drive system for an ultra-large casting crane, characterized in that, include: The rectifier feedback system, main lifting drive system, auxiliary lifting drive system, main trolley drive system, auxiliary trolley drive system and trolley drive system each work independently and drive the corresponding mechanism to operate. The rectifier feedback system provides power and regenerative energy feedback to all drive systems; The rectification feedback system includes: a first rectification feedback system and a second rectification feedback system; the first rectification feedback system and the second rectification feedback system have identical configurations; under normal operating conditions, the first rectification feedback system and the second rectification feedback system operate independently; when either system fails, the other system supplies power to all drive systems to ensure continued operation of the equipment; The first set of rectification feedback system includes: rectification feedback unit U11, incoming line circuit breaker Q11, and outputs the first common DC bus after passing through disconnecting switch Q01; the main hoisting first set of drive system, auxiliary hoisting drive system, main trolley first set of drive system and trolley first set of drive system are connected to the first common DC bus through their respective DC disconnecting switches to obtain power supply; The second set of rectification feedback system includes: rectification feedback unit U12, incoming circuit breaker Q12, and outputs a second common DC bus after passing through disconnect switch Q02; the main hoisting second set of drive system, auxiliary trolley drive system, main trolley second set of drive system and trolley second set of drive system are connected to the second common DC bus through their respective DC disconnect switches to obtain power supply; The main hoisting mechanism adopts a planetary reducer model; the main hoisting drive system includes: a first main hoisting drive system and a second main hoisting drive system, the two systems are completely identical in configuration and jointly drive the main hoisting planetary reducer. The main hoisting first drive system includes: inverter U21, inverter U22, inverter U23, motor M21, and motor M22; the input terminals of the three inverters are connected to the first common DC bus via isolating switches Q21, Q22, and Q23, and the output terminals of the three inverters are connected to motors M21 and M22 via switching switches Q211, Q221, and Q231; when inverter U21 or inverter U22 fails, it switches to the backup inverter U23 to ensure the normal operation of the main hoisting mechanism; The second drive system for the main hoisting mechanism includes: inverters U24, U25, and U26; motors M23 and M24; the input terminals of the three inverters are connected to the second common DC bus via isolating switches Q24, Q25, and Q26; the output terminals of the three inverters are connected to motors M23 and M24 via switching switches Q241, Q251, and Q261; when inverter U24 or inverter U25 fails, the system switches to the backup inverter U26 to ensure the normal operation of the main hoisting mechanism. The main vehicle drive system includes: a first drive system for the main vehicle and a second drive system for the main vehicle; The first drive system of the main trolley includes: inverter U41, motor M41, and motor M42; the input terminal of inverter U41 is connected to the first common DC bus via isolating switch Q41, and the output terminal of inverter U41 is connected to motor M41 and motor M42 via motor circuit breaker Q411 and motor circuit breaker Q412. The second drive system of the main trolley includes: inverter U42, motor M43, and motor M44; the input terminal of inverter U42 is connected to the second common DC bus via isolating switch Q42, and the output terminal of inverter U42 is connected to motor M43 and motor M44 via motor circuit breaker Q421 and motor circuit breaker Q422. The capacity of inverters U41 and U42 is sufficient for the normal operation of the mechanism. Under normal circumstances, inverters U41 and U42 are used simultaneously. When one inverter fails, the other inverter drives the entire mechanism to continue operating.

2. The redundant frequency conversion drive system for an ultra-large casting crane according to claim 1, characterized in that, The rectification feedback system is an active adjustment type rectification unit, and the capacity of each rectification unit can meet the simultaneous normal operation of both the main hoisting and the trolley mechanisms.

3. The redundant frequency conversion drive system for an ultra-large casting crane according to claim 1, characterized in that, The main hoisting drive system adopts a staggered start method, starting one set of motors first, and then starting another set of motors when the motors reach their rated speed.

4. The redundant frequency conversion drive system for an ultra-large casting crane according to claim 1, characterized in that, The auxiliary lifting drive system includes inverters U31 and U32, which drive a motor M31. The input terminals of the two inverters in the auxiliary lifting drive system are connected to the first common DC bus via isolation switches Q31 and Q32, and the output terminals of the two inverters are connected to the motor M31 via a switching switch Q33. During normal operation, the motor is driven by one inverter. When this inverter fails, the system can switch to the other inverter to ensure that the mechanism can continue to operate normally.

5. The redundant frequency conversion drive system for an ultra-large casting crane according to claim 1, characterized in that, The auxiliary trolley drive system includes inverters U51 and U52, which drive motor M51. The input terminals of the two inverters in the auxiliary trolley drive system are connected to the second common DC bus via isolating switches Q51 and Q52, and the output terminals of the two inverters are connected to motor M51 via switching switch Q53. During normal operation, the trolley is driven by one inverter. When this inverter fails, it can be switched to the other inverter to ensure that the mechanism can continue to work normally.

6. The redundant frequency conversion drive system for an ultra-large casting crane according to claim 1, characterized in that, The vehicle drive system includes: a first vehicle drive system and a second vehicle drive system; The first drive system of the large vehicle includes: inverter U61, which is used to drive motor M61 and motor M62; the input terminal of inverter U61 is connected to the first common DC bus via isolating switch Q61, and the output terminal of inverter U61 is connected to motor M61 and motor M62 via motor circuit breaker Q611 and motor circuit breaker Q612; The second drive system of the large vehicle includes: inverter U62, which is used to drive motor M63 and motor M64; the input terminal of inverter U62 is connected to the second common DC bus via isolating switch Q62, and the output terminal of inverter U62 is connected to motor M63 and motor M64 via motor circuit breaker Q621 and motor circuit breaker Q622; The capacity of inverters U61 and U62 is sufficient for the normal operation of the mechanism. Under normal circumstances, inverters U61 and U62 are used simultaneously. When one inverter fails, the other inverter drives the entire mechanism to continue to operate normally.

Images