Energy storage and saving system

Abstract

The embodiment of the utility model relates to the technical field of power consumption management, in particular to an energy storage and saving system which comprises a box-type transformer energy storage system and an energy saving system which are connected in the same power supply bus. Wherein the box-type transformer energy storage system comprises a box-type transformer and a reverse power detection module, and the reverse power detection module is used for detecting whether reverse feedback electricity exists in a secondary side power supply bus of the box-type transformer; the energy-saving system comprises a four-quadrant inversion unit, wherein the four-quadrant inversion unit is used for carrying out rectification and inversion feedback on a direct current bus of the portal crane. Based on the system, when a plurality of portal cranes under the same box-type transformer work together, feedback electricity can be mutually utilized for the second time, and a small part of residual feedback electricity which is not consumed in time is intensively stored on the energy storage system of the box-type transformer, so that the operation energy consumption of equipment is reduced, and an effective energy-saving effect is achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electricity management, and in particular to an energy storage and energy-saving system. Background Art

[0002] In container terminal yard container loading and unloading operations, the most common method is to use gantry cranes as loading and unloading equipment to achieve container loading and unloading. However, the existing container terminal gantry crane loading and unloading operations consume a lot of energy and lack an effective energy-saving method. Its one-way rectifier has no power recovery function, and the rectifier used by the original gantry crane is a one-way rectifier without power feedback function. Since the inverters of the hoisting, trolley and car mechanisms of the original gantry crane are directly connected in parallel to the DC bus, the braking resistor energy consumption braking is used when decelerating and stopping. When the hoisting mechanism descends and the three main mechanisms decelerate, the motor is in the power generation state, and the feedback electricity increases the DC bus voltage. When the DC bus voltage exceeds the threshold, the braking resistor starts to work and converts the electric energy exceeding the threshold into heat energy for consumption. In addition, the operating conditions have high requirements for the energy storage system: the gantry crane is frequently lifted and lowered, and the instantaneous values ​​of the feedback voltage and current are large, which places high requirements on the energy storage battery. Ordinary lithium batteries are not suitable for this operating condition, and special power batteries that can be charged and discharged at a high rate are required. This leads to expensive system costs, unclear energy-saving benefits, and difficulty in promotion and construction.

[0003] Therefore, it is necessary to propose an energy storage and energy-saving system for container terminal gantry cranes to achieve better energy-saving benefits. Utility Model Content

[0004] One purpose of the embodiments of the present application is to provide an energy storage and energy-saving system to solve the technical problems of high energy consumption and lack of effective energy-saving solutions for current container terminal gantry cranes.

[0005] In a first aspect, an embodiment of the present application provides an energy storage and energy-saving system, which is applied to a gantry crane. The energy storage and energy-saving system includes a box-type transformer energy storage system and an energy-saving system. The box-type transformer energy storage system and the energy-saving system are connected to the same power supply bus, wherein:

[0006] The box-type transformer energy storage system comprises a box-type transformer and a reverse power detection module, wherein the reverse power detection module is used to detect whether there is reverse feedback power in the secondary side power supply bus of the box-type transformer;

[0007] The energy-saving system includes a four-quadrant inverter unit, which is used to rectify and invert the DC bus of the gantry crane.

[0008] In combination with the first aspect, in a possible implementation, the box-type transformer energy storage system also includes multiple switch cabinets and multiple gantry cranes, and the number of the multiple gantry cranes is the same as the number of the multiple switch cabinets, so that each switch cabinet controls the power supply of each gantry crane.

[0009] In combination with the first aspect, in a possible implementation, the box-type transformer energy storage system also includes an energy storage inverter and an energy storage system, the energy storage system is used to centrally store the feedback electricity of the gantry crane, and the energy storage inverter is used to synchronously adjust the voltage and current of the secondary side power supply bus of the box-type transformer and the energy storage system.

[0010] In combination with the first aspect, in a possible implementation, the energy-saving system also includes an auxiliary transformer, which is connected between the four-quadrant inverter unit and the electrical equipment, and is used to transform the current passing through the four-quadrant inverter unit to power the electrical equipment.

[0011] In combination with the first aspect, in a possible implementation, the energy-saving system also includes a lifting motor, a trolley motor, a trolley motor, a lifting inverter, a trolley inverter, and a trolley inverter. The lifting inverter, the trolley inverter, and the trolley inverter are all connected to the four-quadrant inverter unit for power supply. The lifting inverter is used to perform frequency control on the lifting motor, the trolley inverter is used to perform frequency control on the trolley motor, and the trolley inverter is used to perform frequency control on the trolley motor.

[0012] In combination with the first aspect, in a possible implementation, the four-quadrant inverter unit in the energy-saving system transforms 460V AC into 380V AC for use by the lifting motor, trolley motor, trolley motor, lifting inverter, trolley inverter, and trolley inverter.

[0013] In combination with the first aspect, in a possible implementation, the box-type transformer is used to convert a 10KV incoming line voltage into a 460V outgoing line voltage.

[0014] The embodiments of the present application can achieve the following technical effects:

[0015] The embodiment of the present application provides an energy storage and energy-saving system applied to gantry cranes at container terminals. Based on this system, a centralized energy storage mode is adopted so that when multiple gantry cranes work together under the same box-type transformer, the feedback electricity can be reused for each other, and the remaining small part of the feedback electricity that will not be consumed in the future is centrally stored in the box-type transformer energy storage system. After the potential energy feedback electricity of the crane is consumed by the synchronously operating equipment, the peak current is low, and the energy storage battery can use an ordinary energy storage lithium battery, without the need to configure a special power battery pack for high-rate charging and discharging, thereby greatly reducing the configuration cost of the energy storage battery, realizing the potential energy recovery and energy storage energy saving of the gantry crane at a relatively low cost, and reducing the energy consumption of equipment operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 A schematic diagram of the structure of the energy storage and energy saving system provided in the embodiment of the present application;

[0018] Figure 2 Another structural schematic diagram of the energy storage and energy saving system provided in the embodiment of the present application;

[0019] Figure 3 Another structural schematic diagram of the energy storage and energy-saving system provided in an embodiment of the present application.

[0020] Figure markings: 1-box-type transformer; 2-reverse power detection module 2; 3-energy storage converter; 4-energy storage system; 5-four-quadrant inverter unit; 6-auxiliary transformer; 7-electrical equipment; 8-hoisting inverter; 9-trolley inverter; 10-trolley inverter; 11-hoisting motor; 12-trolley motor; 13-trolley motor; 20-box-type transformer energy storage system; 21-switch cabinet; 22-switch cabinet; 23-switch cabinet; 24-switch cabinet; 25-switch cabinet; 26-switch cabinet; 27-switch cabinet; 28-switch cabinet; 30-energy-saving system; 31-gantry crane; 32-gantry crane; 33-gantry crane; 34-gantry crane; 35-gantry crane; 36-gantry crane; 37-gantry crane; 38-gantry crane. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0022] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0023] In order to better explain the present application, the application scenarios involved in the present application are first introduced and explained. The energy storage and energy-saving systems provided in the following embodiments of the present application are all applied to gantry cranes at container terminals. In container loading and unloading operations at container terminal yards, the most common method is to use gantry cranes as loading and unloading equipment to achieve container loading and unloading. The energy consumption conditions and processes of the existing container terminal gantry crane drive system are as follows:

[0024] The grid voltage generates a DC bus of about 650VDC after passing through the unidirectional rectifier unit. On the DC bus, the hoist, trolley, and carriage inverters and brake units are connected in parallel. The motor power of the hoist, trolley, and carriage is about 180KW, 20KW, and 40KW. The container terminal gantry crane drive system mainly has three working conditions:

[0025] Working condition 1, starting operation stage: when the hoist is upward or the trolley is working, the motor is in the starting operation condition, obtaining power from the DC bus, and the DC bus voltage drops instantly. After steady-state operation, the DC bus is relatively stable;

[0026] Working condition 2, braking stage: when lifting, descending or decelerating, the motor is in the braking process, at this time, the potential energy is converted into electrical energy, generating feedback electricity, which is fed back to the DC bus, causing the DC bus voltage to increase;

[0027] Working condition 3, absorption stage: When the motor is running, when the DC bus rises to about 740VDC, it will cause the inverter to overvoltage protection and stop working. At this time, the braking unit needs to work to consume the generated electrical energy through the heating of the braking resistor.

[0028] However, in the existing container terminal gantry crane loading and unloading operations, energy consumption is high and the energy-saving potential has not been fully tapped. The main reasons are as follows:

[0029] 1. One-way rectifier without power recovery function: The rectifier used in the original gantry crane is a one-way rectifier without power feedback function. The inverters of the hoisting, trolley and carriage mechanisms of the original gantry crane are directly connected in parallel to the DC bus. When decelerating and stopping, the braking resistor energy consumption braking is used. When the hoisting mechanism descends and the three main mechanisms decelerate, the motor is in the power generation state. The feedback power increases the DC bus voltage. When the DC bus voltage exceeds the threshold, the braking resistor starts to work and converts the electric energy exceeding the threshold into heat energy for consumption.

[0030] 2. The operating conditions have high requirements for the energy storage system: the gantry crane is frequently lifted and lowered, and the instantaneous values ​​of the feedback voltage and current are large, which places high requirements on the energy storage battery. Ordinary lithium batteries are not suitable for this working condition, and special power batteries that can be charged and discharged at a high rate are required. This leads to expensive system costs, unclear energy-saving benefits, and difficulty in promotion and construction.

[0031] Based on this, the present application proposes a centralized energy storage and energy-saving system in the following embodiments to solve the above problems.

[0032] Please refer to Figure 1-3 , Figure 1-3 Shown is a structural schematic diagram of the energy storage and energy-saving system provided in an embodiment of the present application. As shown in the figure, the energy storage and energy-saving system includes a box-type transformer energy storage system and an energy-saving system, and the box-type transformer energy storage system and the energy-saving system are connected to the same power supply bus, wherein: the box-type transformer energy storage system 20, the box-type transformer energy storage system 20 includes a box-type transformer 1 and a reverse power detection module 2, the reverse power detection module 2 is used to detect whether there is reverse feedback power in the secondary side power supply bus of the box-type transformer 1; the energy-saving system 30, the energy-saving system includes a four-quadrant inverter unit 5, and the four-quadrant inverter unit 5 is used to rectify and invert the DC bus of the gantry crane.

[0033] In some embodiments, the box-type transformer energy storage system also includes multiple switch cabinets 24 and multiple gantry cranes, and the number of the multiple gantry cranes is the same as the number of the multiple switch cabinets 24, so that each switch cabinet 24 controls the power supply of each gantry crane.

[0034] In some embodiments, the box-type transformer energy storage system also includes an energy storage inverter 3 and an energy storage system 4, wherein the energy storage system 3 is used to centrally store the feedback electricity of the gantry crane, and the energy storage inverter 4 is used to synchronously adjust the voltage and current of the secondary side power supply bus of the box-type transformer and the energy storage system.

[0035] It is easy to understand that in this system, a four-quadrant inverter unit is used to realize the rectification and inverter feedback functions of the gantry crane DC bus, and the voltage and current are monitored to ensure that the feedback power meets the power quality of the power grid; a reverse power detection module 2 is used to detect whether there is reverse feedback power on the secondary side power supply bus of the transformer; an energy storage converter is used to synchronously adjust the voltage and current of the secondary side power supply bus of the transformer and the energy storage system; and an energy storage system is used to centrally store and power the feedback power of the gantry crane.

[0036] As a feasible implementation method, the feedback power of the four-quadrant inverter unit complies with the control criteria of the power quality of the power grid: when the feedback power voltage is inverted based on 460V, the allowable deviation is ±10%, the feedback power current harmonic is less than 5%, and the system control response time is less than 10 milliseconds.

[0037] In some embodiments, the energy-saving system also includes an auxiliary transformer 6, which is connected between the four-quadrant inverter unit 5 and the electrical equipment 7, and is used to transform the current passing through the four-quadrant inverter unit 5 to supply power to the electrical equipment 7.

[0038] In some embodiments, the energy-saving system also includes a lifting motor 11, a trolley motor 12, a trolley motor 13, a lifting inverter 8, a trolley inverter 9, and a trolley inverter 10. The lifting inverter 8, the trolley inverter 9, and the trolley inverter 10 are all connected to the four-quadrant inverter unit 5 for power supply. The lifting inverter 8 is used to perform frequency control on the lifting motor 11, the trolley inverter 9 is used to perform frequency control on the trolley motor 13, and the trolley inverter 10 is used to perform frequency control on the trolley motor 13.

[0039] In some embodiments, the operation modes of the four-quadrant inverter unit 5 include:

[0040] Rectification mode, the four-quadrant inverter unit 5 monitors the voltage value of the DC bus in real time in the rectification mode to ensure that the voltage value of the DC bus is stable at a preset first voltage value; and inversion mode, when the voltage value of the DC bus is higher than a preset second voltage value, the four-quadrant inverter unit 5 switches to the inversion mode to feed back the voltage value of the DC bus to the AC power grid.

[0041] In some embodiments, the four-quadrant inverter unit in the energy-saving system transforms 460V AC into 380V AC for use by the lifting motor, trolley motor, trolley motor, lifting inverter, trolley inverter, and trolley inverter.

[0042] In some embodiments, the box-type transformer is used to convert the incoming line voltage of 10KV into the outgoing line voltage of 460V.

[0043] Based on the above embodiments, the box-type transformer adopts a centralized energy storage mode. When multiple gantry cranes work together under the same box-type transformer, the feedback electricity can be reused for each other, and the remaining small part of the feedback electricity that will not be consumed in the future is centrally stored in the ground box-type transformer energy storage system. After the crane potential energy feedback electricity is consumed by the synchronous operating equipment, the peak current is low, and the energy storage battery can use an ordinary energy storage lithium battery. There is no need to configure a special power battery pack for high-rate charging and discharging, thereby greatly reducing the configuration cost of the energy storage battery, realizing the potential energy recovery and energy storage energy saving of the gantry crane at a lower cost, reducing the energy consumption of equipment operation, and making the application have a higher application and promotion value.

[0044] It is known from common technical knowledge that the present application can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present application or within the scope equivalent to the present application are included in the present application.

[0045] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0046] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0047] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0048] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. An energy storage and energy saving system, applied to gantry cranes, It is characterized in that The energy storage and energy-saving system comprises a box-type transformer energy storage system and an energy-saving system, wherein the box-type transformer energy storage system and the energy-saving system are connected to the same power supply bus, wherein: The box-type transformer energy storage system comprises a box-type transformer and a reverse power detection module, wherein the reverse power detection module is used to detect whether there is reverse feedback power in the secondary side power supply bus of the box-type transformer; The energy-saving system includes a four-quadrant inverter unit, which is used to rectify and invert the DC bus of the gantry crane.

2. The energy storage and energy saving system according to claim 1, It is characterized in that The box-type transformer energy storage system also includes multiple switch cabinets and multiple gantry cranes, and the number of the multiple gantry cranes is the same as the number of the multiple switch cabinets, so that each switch cabinet controls the power supply of each gantry crane.

3. The energy storage and energy saving system according to claim 2, It is characterized in that The box-type transformer energy storage system also includes an energy storage inverter and an energy storage system. The energy storage system is used to centrally store the feedback electricity of the gantry crane, and the energy storage inverter is used to synchronously adjust the voltage and current of the secondary side power supply bus of the box-type transformer and the energy storage system.

4. The energy storage and energy saving system according to claim 1, It is characterized in that The energy-saving system also includes an auxiliary transformer, which is connected between the four-quadrant inverter unit and the electrical equipment and is used to transform the current passing through the four-quadrant inverter unit to supply power to the electrical equipment.

5. The energy storage and energy saving system according to claim 1, It is characterized in that The energy-saving system also includes a lifting motor, a trolley motor, a trolley motor, a lifting inverter, a trolley inverter, and a trolley inverter. The lifting inverter, the trolley inverter, and the trolley inverter are all connected to the four-quadrant inverter unit for power supply. The lifting inverter is used to perform frequency control on the lifting motor, the trolley inverter is used to perform frequency control on the trolley motor, and the trolley inverter is used to perform frequency control on the trolley motor.

6. The energy storage and energy saving system according to claim 5, It is characterized in that The four-quadrant inverter unit in the energy-saving system transforms 460V AC into 380V AC for use by the lifting motor, trolley motor, car motor, lifting inverter, trolley inverter, and car inverter.

7. The energy storage and energy saving system according to claim 1, It is characterized in that The box-type transformer is used to convert the incoming line voltage of 10KV into the outgoing line voltage of 460V.

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