Rail-mounted gantry crane electric control system

Abstract

The invention relates to the technical field of rail-mounted gantry crane power supply, and discloses a rail-mounted gantry crane electric control system which comprises a ground power supply unit which comprises a high-voltage wire inlet cabinet, a high-voltage transformer, a low-voltage wire inlet cabinet, a reactance cabinet and a rectifier cabinet which are electrically connected in sequence, the input end of the high-voltage wire inlet cabinet is connected with a power grid; the input end of the common direct current bus is connected with the output end of the rectifier cabinet; the input end of the auxiliary power line is connected with the alternating current output end of the low-voltage wire inlet cabinet; and the rail-mounted crane mechanism is connected to the common direct-current bus and the auxiliary power line in parallel. The high-voltage wire inlet cabinet, the low-voltage wire inlet cabinet, the reactance cabinet and the rectifier cabinet are integrated on the ground power supply unit, so that complicated high-voltage power supply and rectifier equipment is prevented from being independently arranged on each rail-mounted gantry crane mechanism, the total quantity and investment cost of the equipment in the rail-mounted gantry crane mechanism can be reduced, the electric energy transmission efficiency is improved, and the energy loss is reduced.

Description

Technical Field

[0001] This invention relates to the field of power supply technology for rail-mounted gantry cranes, and more specifically to an electrical control system for rail-mounted gantry cranes. Background Art

[0002] To ensure the operational advantages of port terminals and maintain good economic benefits, ports need to continuously reduce costs and increase efficiency. For container terminals, the procurement and subsequent operation and maintenance costs of container port machinery equipment are extremely high, making it crucial to reduce the investment and operating costs of port machinery equipment essential for the terminal.

[0003] As port machinery equipment has matured, the electrical control system architecture of container rail-mounted gantry cranes based on individual machines is now largely fixed, with relatively stable configurations for basic electrical control components, leaving limited room for cost reduction. Furthermore, with the advancement of automated, intelligent, and green port construction, port machinery equipment is seeing increased investment in automated supporting systems, new energy sources, and energy storage systems. This leads to continuously rising operating and maintenance costs for individual machines, placing a heavy economic burden on terminals and hindering further investment in new technologies for port machinery. Summary of the Invention

[0004] In view of this, the present invention provides a rail-mounted gantry crane electrical control system to solve the problem of high construction economic cost and high operating energy consumption cost of port machinery equipment in the prior art.

[0005] In a first aspect, the present invention provides a rail-mounted crane electrical control system, comprising:

[0006] The ground power supply unit includes a high-voltage incoming cabinet, a high-voltage transformer, a low-voltage incoming cabinet, a reactor cabinet, and a rectifier cabinet connected in sequence. The rectifier cabinet is used to rectify AC power into DC power. The input terminal of the high-voltage incoming cabinet is connected to the power grid.

[0007] A common DC bus, the input end of which is connected to the output end of the rectifier cabinet;

[0008] An auxiliary power supply cable, the input end of which is connected to the AC output end of the low-voltage incoming line cabinet;

[0009] The rail-mounted crane mechanism is connected in parallel to the common DC bus and the auxiliary power supply line.

[0010] The rail-mounted gantry crane's electrical control system supplies power to the gantry crane mechanism via a ground power supply unit. In this unit, the high-voltage incoming cabinet obtains high-voltage power from the power grid, which is then stepped down by a high-voltage transformer before being transmitted to the low-voltage incoming cabinet for further voltage reduction. The stepped-down power is then transmitted in two paths: one to the reactor cabinet and the other to the rectifier cabinet. The rectifier cabinet converts the AC power to DC power, which then supplies power to the high-voltage equipment of the gantry crane mechanism via a common DC bus. The other path serves as an auxiliary power supply, directly providing AC power to the auxiliary equipment of the gantry crane mechanism via an auxiliary power line. The rail-mounted gantry crane's electrical control system adopts a centralized ground power supply model, integrating the high-voltage, low-voltage, reactor, and rectifier cabinets into the ground power supply unit. This avoids the need for separate, complex high-voltage power supply and rectifier equipment on each gantry crane mechanism, significantly reducing the overall number of devices and investment costs. Simultaneously, the unified power supply to multiple gantry crane mechanisms via a common DC bus enables centralized management and optimized distribution of power, greatly improving power transmission efficiency and reducing energy loss.

[0011] In one optional embodiment, a capacitor energy storage device is connected to the common DC bus. The capacitor energy storage device is used to absorb and store regenerated energy through the common DC bus when the overall power of the rail gantry crane is in a potential energy regeneration state, thereby recovering excess electrical energy when the rail gantry crane is performing lifting operations, improving energy utilization efficiency and reducing operating costs.

[0012] In one optional implementation, when the energy storage in the capacitor energy storage device reaches its maximum value, the excess energy is inverted into AC power through the rectifier cabinet and finally fed back to the power grid, preventing the capacitor energy storage device from overloaded. At the same time, the excess energy is fed back to the power grid, further improving energy utilization efficiency and reducing energy waste.

[0013] In one optional implementation, when the overall power of the rail-mounted gantry crane is in electric operation mode, the capacitor energy storage device releases the stored electrical energy. Adjusting the discharge duration of the capacitor energy storage device allows for power compensation of the rectifier cabinet. By providing reactive current through the capacitor energy storage device to compensate for the reactive power generated by the inductive load, the flow of reactive power can be reduced, thereby reducing the power loss of transformers and the common DC bus in the transmission and distribution lines, and lowering overall power consumption and energy costs.

[0014] In one optional implementation, the common DC bus is connected to a braking resistor. When the capacitor storage device is unable to absorb all the regenerated energy, the braking resistor can convert the excess electrical energy into heat energy, preventing system overvoltage, protecting equipment safety, and ensuring stable system operation.

[0015] In one optional embodiment, the common DC bus is a sliding contact line, which is laid along the trolley travel direction of the rail-mounted crane mechanism. The use of a sliding contact line facilitates free movement of the rail-mounted crane in the trolley travel direction while providing a continuous and stable power supply, ensuring the reliability and flexibility of the rail-mounted crane during long-distance operation.

[0016] In one optional embodiment, the auxiliary power cable is a flexible cable, which is wound onto a cable reel. This facilitates the winding and unwinding of the auxiliary power cable, adapts to the power supply needs of equipment inside the rail-mounted crane structure at different locations, and improves the power supply stability and reliability of the auxiliary equipment.

[0017] In one optional embodiment, the rail-mounted gantry mechanism includes a DC busbar, an auxiliary power interface, electrical equipment, and auxiliary equipment. The DC busbar is connected to the common DC busbar, the auxiliary power interface is connected to the auxiliary power line, multiple sets of electrical equipment are installed in parallel on the DC busbar, and each electrical equipment is connected to the DC busbar via an inverter. The auxiliary equipment is electrically connected to the auxiliary power interface.

[0018] In one alternative implementation, the input terminal of the DC bus is connected to a current transformer and a voltage transformer.

[0019] In one optional implementation, multiple sets of the rail-mounted gantry crane mechanisms are installed in parallel. These parallel-installed gantry crane mechanisms can share the same ground power supply unit, achieving efficient utilization of equipment resources and reducing overall equipment costs. Simultaneously, this parallel configuration enhances the system's power supply capacity, enabling it to simultaneously meet the power demands of multiple rail-mounted gantry cranes operating concurrently, thereby improving port operational efficiency and handling capacity. Attached Figure Description

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the rail crane electrical control system provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the internal circuit structure of the rail-mounted crane mechanism provided in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached diagram: 1. Power grid; 2. High-voltage incoming switchgear; 3. High-voltage transformer; 4. Low-voltage incoming switchgear; 5. Reactor cabinet; 6. Rectifier cabinet; 7. Capacitor energy storage device; 8. Braking resistor; 9. Rail-mounted gantry mechanism; 10. Common DC busbar; 11. Auxiliary power supply line; 12. Electrical equipment; 13. Cable reel; 14. Inverter; 15. Auxiliary transformer; 16. Ground electrical room. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0025] The following is combined Figures 1 to 2 The following describes embodiments of the present invention.

[0026] According to an embodiment of the present invention, in one aspect, a rail-mounted gantry crane electrical control system is provided, including a ground power supply unit, a common DC bus 10, an auxiliary power supply line 11, and a rail-mounted gantry crane mechanism 9 as an electrical-consuming mechanism.

[0027] The ground power supply unit internally comprises a high-voltage incoming cabinet 2, a low-voltage incoming cabinet 4, a reactor cabinet 5, and a rectifier cabinet 6, which are connected in sequence. The rectifier cabinet 6 is used to rectify AC power into DC power. The input terminal of the high-voltage incoming cabinet 2 is connected to the power grid 1. The input terminal of the common DC bus 10 is connected to the output terminal of the rectifier cabinet 6. The input terminal of the auxiliary power line 11 is connected to the AC output terminal of the low-voltage incoming cabinet 4. The rail-mounted gantry mechanism 9 is connected in parallel to the common DC bus 10 and the auxiliary power line 11.

[0028] The rail-mounted gantry crane's electrical control system supplies power to the gantry crane mechanism 9 via a ground power supply unit. In this unit, the high-voltage incoming cabinet 2 receives high-voltage power from the power grid 1, which is then stepped down by the high-voltage transformer 3 before being transmitted to the low-voltage incoming cabinet 4 for further voltage reduction. The stepped-down power is then transmitted in two ways: one to the reactor cabinet 5 and the rectifier cabinet 6, where the rectifier cabinet 6 converts the AC power to DC power, which is then supplied to the high-voltage electrical equipment 12 of the gantry crane mechanism 9 via a common DC bus 10; the other path serves as an auxiliary power supply, directly providing AC power to the auxiliary equipment of the gantry crane mechanism 9 via the auxiliary power line 11. The rail-mounted gantry crane's electrical control system adopts a centralized ground power supply model, integrating the high-voltage incoming cabinet 2, low-voltage incoming cabinet 4, reactor cabinet 5, and rectifier cabinet 6 into the ground power supply unit. This avoids the need for separate, complex high-voltage power supply and rectification equipment on each gantry crane mechanism 9, significantly reducing the overall number of devices and investment costs within the gantry crane mechanism 9. Meanwhile, the common DC bus 10 provides unified power supply to multiple rail-mounted gantry cranes 9, realizing centralized management and optimized distribution of electrical energy, which can greatly improve the efficiency of power transmission and reduce energy loss.

[0029] In this embodiment, the ground power supply unit is installed in the ground electrical room 16, where the high-voltage incoming cabinet 2 and the high-voltage transformer 3 provide power to the entire rail-mounted gantry crane. The high-voltage electricity is stepped down by the high-voltage transformer 3 and then enters the main low-voltage incoming cabinet 4. The power supply is divided into two paths within the low-voltage incoming cabinet 4: one main power supply serves as the power input to the reactor cabinet 5 and rectifier cabinet 6 for the multi-drive system; the other is the auxiliary power supply used by the auxiliary and control equipment of each rail-mounted gantry crane. The auxiliary power supply is connected to the machine via the rail-mounted gantry crane cable reel 13.

[0030] In one embodiment, a capacitor energy storage device 7 is connected to the common DC bus 10. The capacitor energy storage device 7 is used to absorb and store regenerated energy through the common DC bus 10 when the overall power of the rail gantry crane is in a potential energy regeneration state. This enables the rail gantry crane to effectively recover excess electrical energy during lifting operations, thereby significantly improving the energy utilization efficiency of the entire system and reducing port operating costs.

[0031] As an alternative, a secondary battery energy storage device can be added in conjunction with the capacitor energy storage device 7 to store more renewable energy, which is suitable for rail-mounted gantry systems that operate for extended periods and further enhances the energy recovery effect.

[0032] In this embodiment, when the energy storage in the capacitor energy storage device 7 reaches its maximum value, the excess energy is inverted into AC power through the rectifier cabinet 6 and finally fed back to the power grid 1, thereby effectively preventing the capacitor energy storage device 7 from overloaded. At the same time, the unused energy is fed back to the power grid 1, further improving energy utilization efficiency and reducing energy waste.

[0033] Furthermore, when the rail gantry crane mechanism 9 is in an electrically powered state, the capacitor energy storage device 7 is designed to release its previously stored electrical energy. By precisely adjusting the discharge duration of the capacitor energy storage device 7, the released electrical energy can be used to compensate the power of the rectifier cabinet 6. During this process, the capacitor energy storage device 7 provides reactive current to compensate for the reactive power generated by the inductive load, effectively reducing the flow of reactive power in the system, thereby reducing the power loss of transformers and the common DC bus 10 in the transmission and distribution lines, ultimately achieving a reduction in overall power consumption and energy costs. In some other embodiments, a static var generator can also be installed on the common DC bus 10. When the rail gantry crane is in an electrically powered state, the capacitor energy storage device 7 works in conjunction with the static var generator. The static var generator quickly adjusts its output reactive power by monitoring the reactive power demand of the power grid 1 in real time, ensuring that the power factor of the power grid 1 remains at a high level, further reducing reactive power flow and lowering power loss.

[0034] In one embodiment, a braking resistor 8 is connected to the common DC bus 10. When the capacitor energy storage device 7 cannot absorb all the regenerated energy, the braking resistor 8 can convert the excess electrical energy into heat energy. This effectively prevents overvoltage of the capacitor energy storage device 7 in the power supply system, protects the safe operation of the capacitor energy storage device 7 and the power supply system, and ensures the stable operation of the entire rail-mounted crane electrical control system.

[0035] In one embodiment, the common DC bus 10 is a sliding contact line, which is laid along the trolley travel direction of the rail-mounted crane mechanism 9. The use of a sliding contact line facilitates the free movement of the rail-mounted crane in the trolley travel direction, while providing a continuous and stable power supply, ensuring the reliability and flexibility of the rail-mounted crane during long-distance operation.

[0036] In some other embodiments, the common DC bus 10 can also employ a combination system of flexible power supply rails and sliding contact lines. Flexible, bendable power supply rails are installed on both sides of the rails of the rail-mounted gantry crane. The power supply rails have embedded brush tracks that contact the energized brushes at the bottom of the rail-mounted crane to supply power. Simultaneously, a sliding contact line power supply method is retained at the starting end and turning points of the rail-mounted crane, allowing the layout of the common DC bus 10 to be adjusted according to actual needs.

[0037] In one embodiment, the auxiliary power cable 11 is a flexible cable, wound onto a cable reel 13. This facilitates the winding and unwinding of the auxiliary power cable 11, adapting to the power supply needs of equipment within the rail-mounted gantry structure at different locations, and improving the power supply stability and reliability of the auxiliary equipment. The auxiliary power cable 11 is used to supply power to the auxiliary equipment in the rail-mounted gantry mechanism 9. An auxiliary transformer 15 is connected to the output end of the auxiliary power cable 11 to transform the AC power on the auxiliary power cable 11 before it is delivered to the auxiliary equipment.

[0038] In one embodiment, the rail-mounted gantry mechanism 9 includes a DC busbar, an auxiliary power interface, electrical equipment 12, and auxiliary equipment. The DC busbar is connected to a common DC busbar 10, and the auxiliary power interface is connected to an auxiliary power line 11. Multiple sets of electrical equipment 12 are installed in parallel on the DC busbar. Each electrical equipment 12 is connected to an inverter 14, and the auxiliary equipment is electrically connected to the auxiliary power interface. In this embodiment, the electrical equipment 12 includes one hoisting motor, two trolley motors, two auxiliary trolley motors, and four gantry traverse motors.

[0039] In one embodiment, a current transformer and a voltage transformer are connected to the input terminal of the DC bus. The installation of the current transformer and voltage transformer enables the system to monitor the current and voltage parameters of the DC bus in real time, providing data support for the safe operation of the system, facilitating the timely detection and handling of power quality problems, and ensuring the stable operation of the equipment.

[0040] In one embodiment, multiple sets of rail-mounted gantry crane mechanisms 9 are installed in parallel. These parallel-installed gantry crane mechanisms 9 can share the same ground power supply unit, achieving efficient utilization of equipment resources and reducing overall equipment costs. Simultaneously, this parallel configuration enhances the system's power supply capacity, enabling it to simultaneously meet the power demands of multiple rail-mounted gantry cranes operating concurrently, thereby improving port operational efficiency and handling capacity.

[0041] In the rail-mounted gantry electrical control system provided in this embodiment, a high-voltage cabinet and a high-voltage transformer 3 are designed and installed in the ground electrical room 16 to provide power to the entire rail-mounted gantry. After being stepped down by the high-voltage transformer 3, the power enters the main low-voltage incoming cabinet 4. The power supply is divided into two paths in the low-voltage incoming cabinet 4: one main power supply serves as the power input to the reactor cabinet 5 and rectifier cabinet 6 for the multi-drive system composed of multiple rail-mounted gantry mechanisms 9; the other is the auxiliary power supply used by the auxiliary and control equipment in each rail-mounted gantry mechanism 9. The auxiliary power supply is connected to the machine through the rail-mounted gantry cable reel 13.

[0042] The independent drive systems of multiple rail-mounted gantry cranes are integrated into a single multi-drive system. The previously separate high-voltage cabinets, reactor cabinets 5, and rectifier cabinets 6 for each rail-mounted gantry crane mechanism 9 are consolidated into a single high-voltage incoming cabinet 2, low-voltage incoming cabinet 4, reactor cabinet 5, and rectifier cabinet 6. The main power input, after passing through reactor cabinet 5 and rectifier cabinet 6 in the ground electrical room 16, is rectified from AC to DC and connected to the DC sliding contact line in the yard. The DC sliding contact line connects to the DC busbar inside each rail-mounted gantry crane mechanism 9. The DC sliding contact line is laid along the direction of the rail-mounted gantry crane's trolley travel. The power configuration of the high-voltage incoming cabinet 2, high-voltage transformer 3, reactor cabinet 5, and rectifier cabinet 6 is based on the rail-mounted gantry crane's operating utilization factor. A supercapacitor energy storage device 7 is connected to the common DC busbar 10. Each electrical device 12 within the electrical system of each rail-mounted gantry crane mechanism 9 is equipped with an inverter 14, eliminating the need for separate high-voltage cabinets, high-voltage transformers 3, rectifiers, and energy storage devices for each individual rail-mounted gantry crane mechanism 9.

[0043] When the entire rail gantry crane is in a potential energy regeneration state, the capacitor energy storage device 7 absorbs and stores regenerated energy through the common DC bus 10. If the capacitor energy storage device 7 is full, the excess energy is inverted into AC power by the rectifier cabinet 6 and fed back to the power grid 1. When the entire rail gantry crane is in an electric power operation state, the rail gantry crane mechanism 9 needs to obtain energy from the power grid 1. At this time, the capacitor energy storage device 7 will release the stored electrical energy. By adjusting the discharge time of the capacitor energy storage device 7, power compensation for the rectifier cabinet 6 can be achieved. The upper-level industrial control computer matches the operating rhythm of each rail gantry crane, controls the dynamic balance of the charging and discharging time of the DC bus, and ensures that the energy storage device can absorb most of the potential energy. By using the upper-level control computer to control the operating rhythm of each main mechanism of the rail gantry crane, the operating cycle time of each rail gantry crane is reasonably allocated, and peak operations are staggered. The power output of the head rectifier device is reduced by utilizing the overlap of the rising and falling cycles. The energy storage device is used to maximize the power compensation and potential energy recovery and reuse of the transmission system. The rated power and current of the system's main high-voltage incoming cabinet 2, high-voltage transformer 3, low-voltage incoming cabinet 4, reactor cabinet 5, rectifier cabinet 6, and capacitor energy storage device 7 are significantly less than the sum of the power of the corresponding parts of the original multiple independent systems, which can effectively reduce the unit energy consumption of each electric actuator inside the rail-mounted crane mechanism 9.

[0044] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A rail-mounted crane electrical control system, characterized in that, include: The ground power supply unit includes a high-voltage incoming cabinet (2), a high-voltage transformer (3), a low-voltage incoming cabinet (4), a reactor cabinet (5), and a rectifier cabinet (6) connected in sequence. The rectifier cabinet (6) is used to rectify AC power into DC power. The input terminal of the high-voltage incoming cabinet (2) is connected to the power grid (1). A common DC bus (10) has its input end connected to the output end of the rectifier cabinet (6); An auxiliary power supply line (11) is connected at its input end to the AC output end of the low-voltage incoming cabinet (4); The rail-mounted crane mechanism (9) is connected in parallel to the common DC bus (10) and the auxiliary power supply line (11).

2. The rail-mounted crane electrical control system according to claim 1, characterized in that, A capacitor energy storage device (7) is connected to the common DC bus (10). The capacitor energy storage device (7) is used to absorb and store regenerated energy through the common DC bus (10) when the overall power of the rail crane is in a potential energy regeneration state.

3. The rail-mounted crane electrical control system according to claim 2, characterized in that, When the energy storage in the capacitor energy storage device (7) reaches its maximum value, the excess energy is inverted into alternating current through the rectifier cabinet (6) and finally fed back to the power grid (1).

4. The rail-mounted crane electrical control system according to claim 2 or 3, characterized in that, When the overall power of the rail crane mechanism (9) is in the electric working state, the capacitor energy storage device (7) releases the stored electrical energy to the outside. Adjust the discharge duration of the capacitor energy storage device (7) and use the capacitor energy storage device (7) to perform power compensation on the rectifier cabinet (6).

5. The rail-mounted crane electrical control system according to any one of claims 1 to 3, characterized in that, The common DC bus (10) is connected to a braking resistor (8).

6. The rail-mounted crane electrical control system according to any one of claims 1 to 3, characterized in that, The common DC bus (10) is a sliding contact line, and the common DC bus (10) is laid out along the running direction of the trolley of the rail crane mechanism (9).

7. The rail-mounted crane electrical control system according to any one of claims 1 to 3, characterized in that, The auxiliary power line (11) is a flexible cable, and the auxiliary power line (11) is wound on the cable reel (13).

8. The rail-mounted crane electrical control system according to any one of claims 1 to 3, characterized in that, The rail-mounted crane mechanism (9) includes a DC busbar, an auxiliary power interface, electrical equipment (12), and auxiliary equipment. The DC busbar is connected to the common DC busbar (10), the auxiliary power interface is connected to the auxiliary power line (11), multiple sets of electrical equipment (12) are installed in parallel on the DC busbar, and an inverter (14) is connected between each electrical equipment (12) and the DC busbar. The auxiliary equipment is electrically connected to the auxiliary power interface.

9. The rail-mounted crane electrical control system according to claim 8, characterized in that, The input terminals of the DC busbar are connected to a current transformer and a voltage transformer.

10. The rail-mounted crane electrical control system according to any one of claims 1 to 3, characterized in that, The rail-mounted gantry mechanism (9) is installed in multiple sets in parallel.

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