Starting method and system for high-capacity motor load power supply system through flexible direct current

Abstract

The invention discloses a method and system for starting a power supply system for supplying power to a high-capacity motor load through flexible direct current, and belongs to the technical field of safe and stable operation and control of a high-proportion new energy system. The starting method comprises the following steps: for a high-capacity motor load power supply system, unlocking a flexible direct current constant direct current voltage control converter station connected with an alternating current main network in the high-capacity motor load power supply system, and charging a direct current side capacitor of the flexible direct current constant direct current voltage control converter station until charging is completed; unlocking a network construction flexible direct current converter station in the high-capacity motor load power supply system, and charging a direct current side capacitor of the network construction flexible direct current converter station until charging is completed; and sequentially starting a near-end motor and a far-end motor of the high-capacity motor load power supply system so as to start the high-capacity motor load power supply system. According to the invention, the reliability of supplying power to the large-capacity motor load in the remote area can be improved, the safe and stable operation capability is improved, and obvious economic benefits are created.

Description

Technical Field

[0001] The present invention relates to the technical field of safe and stable operation and control of a high-proportion new energy system, and more specifically, to a method and system for starting a power supply system for a large-capacity motor load via a flexible direct current. Background Art

[0002] At present, my country is building a new type of power system, one of its typical characteristics is the increasing proportion of new energy. In the scenario of supplying power to large-capacity motor loads far from the main grid, since the output of new energy depends on the distribution of wind and light resources, the reliability of power supply cannot be guaranteed. When there is no wind and no light, there is no electricity available, which may eventually lead to power outages. Flexible direct current can be used to supply power to large-capacity motor loads far from the main grid. However, the startup of this power supply system is more difficult and needs to be coordinated in a certain order. Summary of the invention

[0003] In view of the above problems, the present invention proposes a method for starting a power supply system for a large-capacity motor load via a flexible direct current, comprising:

[0004] For a large-capacity motor load power supply system, unlock the flexible direct current fixed direct current voltage control converter station connected to the AC main grid in the large-capacity motor load power supply system, and charge the DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed;

[0005] Unlocking the grid-building flexible DC converter station in the large-capacity motor load power supply system, and charging the DC side capacitor of the grid-building flexible DC converter station until charging is completed;

[0006] The proximal and distal motors of the large-capacity motor load power supply system are started in sequence to start the large-capacity motor load power supply system.

[0007] Optionally, the large-capacity motor load power supply system is a large-capacity motor load power supply system for remote areas.

[0008] Optionally, a current limiting resistor Rac is configured on the AC side of the flexible direct current constant voltage control converter station. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

[0009] Optionally, after closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-connecting flexible DC converter station is charged. After charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-connecting flexible DC converter station in the large-capacity motor load power supply system.

[0010] Optionally, a current limiting resistor Rdc is configured on the DC side of the networking flexible DC converter station. When the DC side capacitor of the networking flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

[0011] Optionally, starting the proximal and distal motors of the large-capacity motor load power supply system in sequence includes:

[0012] The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including:

[0013] First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

[0014] Optionally, the motor load capacity PM and flexible direct current capacity Pvsc of the large-capacity motor load power supply system meet the following requirements:

[0015] PM<0.5Pvsc.

[0016] On the other hand, the present invention also provides a starting system for supplying power to a large-capacity motor load via flexible direct current, comprising:

[0017] The first unlocking unit is used for unlocking a flexible direct current fixed direct current voltage control converter station connected to an AC main grid in a large-capacity motor load power supply system, and charging a DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed;

[0018] A second unlocking unit is used to unlock the network-building flexible direct current converter station in the large-capacity motor load power supply system, and charge the DC side capacitor of the network-building flexible direct current converter station until the charging is completed;

[0019] The starting unit is used to start the proximal and distal motors of the large-capacity motor load power supply system in sequence to start the large-capacity motor load power supply system.

[0020] Optionally, the large-capacity motor load power supply system is a large-capacity motor load power supply system for remote areas.

[0021] Optionally, a current limiting resistor Rac is configured on the AC side of the flexible direct current constant voltage control converter station. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

[0022] Optionally, after closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-connecting flexible DC converter station is charged. After charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-connecting flexible DC converter station in the large-capacity motor load power supply system.

[0023] Optionally, a current limiting resistor Rdc is configured on the DC side of the networking flexible DC converter station. When the DC side capacitor of the networking flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

[0024] Optionally, starting the proximal and distal motors of the large-capacity motor load power supply system in sequence includes:

[0025] The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including:

[0026] First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

[0027] Optionally, the motor load capacity PM and flexible direct current capacity Pvsc of the large-capacity motor load power supply system meet the following requirements:

[0028] PM<0.5Pvsc.

[0029] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0030] a processor for executing one or more programs;

[0031] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0032] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention proposes a method for starting a large-capacity motor load power supply system via flexible direct current, comprising: for the large-capacity motor load power supply system, unlocking the flexible direct current fixed direct current voltage control converter station connected to the AC main grid in the large-capacity motor load power supply system, and charging the DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed; unlocking the networking flexible direct current converter station in the large-capacity motor load power supply system, and charging the DC side capacitor of the networking flexible direct current converter station until charging is completed; starting the proximal and distal motors of the large-capacity motor load power supply system in sequence to start the large-capacity motor load power supply system. The present invention can improve the reliability of power supply to large-capacity motor loads in remote areas, improve its safe and stable operation capabilities, and create significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flow chart of the method of the present invention;

[0036] Figure 2 A schematic diagram of a system for supplying power to large-capacity motor loads in remote areas via flexible direct current according to an embodiment of the method of the present invention;

[0037] Figure 3 A structural diagram of a system for supplying power to large-capacity motor loads in remote areas via flexible direct current according to an embodiment of the method of the present invention;

[0038] Figure 4 The present invention is a flowchart of a method for starting a system for supplying power to large-capacity motor loads in remote areas via flexible direct current according to an embodiment of the present invention.

[0039] Figure 5 It is a schematic diagram of the starting process of the flexible DC converter station C with AC side starting resistor according to the method embodiment of the present invention;

[0040] Figure 6 It is a schematic diagram of the starting process of flexible DC converter stations A and B with DC side starting resistors according to an embodiment of the method of the present invention;

[0041] Figure 7 A schematic diagram of a motor load rotor connected to a graded resistor for starting according to an embodiment of the method of the present invention;

[0042] Figure 8 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0043] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0044] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0045] Embodiment 1:

[0046] The present invention proposes a method for starting a power supply system for a large-capacity motor load via a flexible direct current. Figure 1 As shown, including:

[0047] Step 1: for a large-capacity motor load power supply system, unlock a flexible direct current fixed direct current voltage control converter station connected to an AC main grid in the large-capacity motor load power supply system, and charge a DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed;

[0048] Step 2: unlocking the network-building flexible DC converter station in the large-capacity motor load power supply system, and charging the DC side capacitor of the network-building flexible DC converter station until charging is completed;

[0049] Step 3: Start the proximal and distal motors of the large-capacity motor load power supply system in sequence to start the large-capacity motor load power supply system.

[0050] Among them, the large-capacity motor load power supply system is a large-capacity motor load power supply system in remote areas.

[0051] Among them, the AC side of the flexible direct current constant voltage control converter station is configured with a current limiting resistor Rac. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

[0052] Among them, after closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-connecting flexible DC converter station is charged. After the charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-connecting flexible DC converter station in the large-capacity motor load power supply system.

[0053] Among them, a current limiting resistor Rdc is configured on the DC side of the grid-forming flexible DC converter station. When the DC side capacitor of the grid-forming flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

[0054] The method of sequentially starting the proximal and distal motors of the large-capacity motor load power supply system includes:

[0055] The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including:

[0056] First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

[0057] Among them, the motor load capacity PM and flexible direct current capacity Pvsc of the large-capacity motor load power supply system meet the following requirements:

[0058] PM<0.5Pvsc.

[0059] The present invention is further described below with reference to specific cases:

[0060] To solve the problem of supplying large-capacity motor loads to remote areas via flexible DC (such as Figure 2 and Figure 3 The present invention is proposed to solve the startup problem of Figure 4 As shown, including:

[0061] (1) Unlocking the flexible DC constant voltage control converter station:

[0062] First, unlock the flexible DC constant voltage control converter station C connected to the AC main grid to charge the DC side capacitor of the flexible DC converter station. Configure the current limiting resistor Rac on the AC side, such as Figure 5 As shown, the transient current impact during the charging process is reduced to prevent damage to the power electronic devices in the converter valve. After the charging is completed, the switch Kac is closed to bypass the charging resistor Rac.

[0063] (2) Unlocking the flexible DC network control converter station:

[0064] First close the circuit breaker C1 and circuit breaker B2, unlock the flexible DC converter station B, and charge the DC side capacitor of the flexible DC converter station B; configure the current limiting resistor Rdc on the DC side, as shown in the attached figure. Figure 5 As shown, transient current impact is reduced to prevent damage to power electronic devices in the converter valve. After the charging current is within the safe range, the bypass switch Kdc can be closed to bypass the current limiting resistor.

[0065] Then close circuit breakers B1 and A1, unlock the flexible DC converter station A, and charge the DC side capacitor of the flexible DC converter station A through the current limiting resistor.

[0066] (3) Start the proximal and distal motors in sequence:

[0067] The rotor series resistance grading method is adopted, such as Figure 7 As shown, the motor loads in the grid are started in batches, first starting the motor loads in the local power supply system B, and then starting the motor loads in the local power supply system A. The capacity of the motor loads started at the same time should be limited to prevent the transient current during the start-up from damaging the power electronic devices in the flexible DC converter station. Assuming that the motor load capacity is PM and the flexible DC capacity is Pvsc, the following requirements should be made for the capacity of the two:

[0068] PM<0.5Pvsc (1)

[0069] To ensure that the flexible direct current will not over-current during the motor startup process. For motor loads in the same area, large-capacity motor loads are started first, followed by small-capacity motor loads. Finally, photovoltaic and energy storage grid-connected in local power supply systems in remote areas can be integrated into the local power supply system in turn according to the commissioning situation.

[0070] Embodiment 2:

[0071] The present invention also proposes a starting system 200 for supplying power to a large-capacity motor load via a flexible direct current. Figure 8 As shown, including:

[0072] The first unlocking unit 201 is used for unlocking a flexible direct current voltage control converter station connected to an AC main grid in a large-capacity motor load power supply system, and charging a DC side capacitor of the flexible direct current voltage control converter station until charging is completed;

[0073] The second unlocking unit 202 is used to unlock the networking flexible DC converter station in the large-capacity motor load power supply system, and charge the DC side capacitor of the networking flexible DC converter station until the charging is completed;

[0074] The starting unit 203 is used to start the proximal and distal motors of the large-capacity motor load power supply system in sequence to start the large-capacity motor load power supply system.

[0075] Among them, the large-capacity motor load power supply system is a large-capacity motor load power supply system in remote areas.

[0076] Among them, the AC side of the flexible direct current constant voltage control converter station is configured with a current limiting resistor Rac. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

[0077] Among them, after closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-connecting flexible DC converter station is charged. After the charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-connecting flexible DC converter station in the large-capacity motor load power supply system.

[0078] Among them, a current limiting resistor Rdc is configured on the DC side of the grid-forming flexible DC converter station. When the DC side capacitor of the grid-forming flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

[0079] The method of sequentially starting the proximal and distal motors of the large-capacity motor load power supply system includes:

[0080] The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including:

[0081] First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

[0082] Among them, the motor load capacity PM and flexible direct current capacity Pvsc of the large-capacity motor load power supply system meet the following requirements:

[0083] PM<0.5Pvsc.

[0084] The present invention can improve the reliability of power supply to large-capacity motor loads in remote areas, improve its safe and stable operation capability, and create significant economic benefits.

[0085] Embodiment 3:

[0086] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0087] Embodiment 4:

[0088] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0089] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0090] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 produce 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.

[0091] 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 comprising 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.

[0092] 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 A step that specifies a function in one or more boxes.

[0093] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0094] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for starting a power supply system for a large-capacity motor load via flexible direct current, characterized in that: include: For a large-capacity motor load power supply system, unlock the flexible direct current fixed direct current voltage control converter station connected to the AC main grid in the large-capacity motor load power supply system, and charge the DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed; Unlocking the grid-building flexible DC converter station in the large-capacity motor load power supply system, and charging the DC side capacitor of the grid-building flexible DC converter station until charging is completed; The proximal and distal motors of the large-capacity motor load power supply system are started in sequence to start the large-capacity motor load power supply system.

2. The startup method according to claim 1, characterized in that: The large-capacity motor load power supply system is a large-capacity motor load power supply system in remote areas.

3. The startup method according to claim 1, characterized in that: The AC side of the flexible direct current constant voltage control converter station is configured with a current limiting resistor Rac. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

4. The startup method according to claim 1, characterized in that: After closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-forming flexible DC converter station is charged. After the charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-forming flexible DC converter station in the large-capacity motor load power supply system.

5. The startup method according to claim 1, characterized in that: The DC side of the network-building flexible DC converter station is configured with a current limiting resistor Rdc. When the DC side capacitor of the network-building flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

6. The startup method according to claim 1, characterized in that: The method of sequentially starting the proximal and distal motors of the large-capacity motor load power supply system includes: The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including: First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

7. The startup method according to claim 1, characterized in that: The motor load capacity PM and the flexible direct current capacity Pvsc of the large-capacity motor load power supply system satisfy the following: PM<0.5Pvsc.

8. A starting system for supplying power to a large-capacity motor load via flexible direct current, characterized in that: include: The first unlocking unit is used for unlocking a flexible direct current fixed direct current voltage control converter station connected to an alternating current main grid in a large-capacity motor load power supply system, and charging a DC side capacitor of the flexible direct current fixed direct current voltage control converter station until charging is completed; A second unlocking unit is used to unlock the network-building flexible direct current converter station in the large-capacity motor load power supply system, and charge the DC side capacitor of the network-building flexible direct current converter station until the charging is completed; The starting unit is used to start the proximal and distal motors of the large-capacity motor load power supply system in sequence to start the large-capacity motor load power supply system.

9. The starting system according to claim 8, characterized in that: The large-capacity motor load power supply system is a large-capacity motor load power supply system in remote areas.

10. The starting system according to claim 8, characterized in that: The AC side of the flexible direct current constant voltage control converter station is configured with a current limiting resistor Rac. When the DC side capacitor of the flexible direct current constant voltage control converter station is charged, the current limiting resistor Rac is started, and after the charging is completed, the current limiting resistor Rac is bypassed.

11. The starting system according to claim 8, characterized in that: After closing the circuit breakers C1 and B2 of the large-capacity motor load power supply system, the DC side capacitor of the grid-forming flexible DC converter station is charged. After the charging is completed, the circuit breakers C1 and B2 are disconnected to unlock the grid-forming flexible DC converter station in the large-capacity motor load power supply system.

12. The starting system according to claim 8, characterized in that: The DC side of the network-building flexible DC converter station is configured with a current limiting resistor Rdc. When the DC side capacitor of the network-building flexible DC converter station is charged, the current limiting resistor Rdc is started, and after the charging is completed, the current limiting resistor Rdc is bypassed.

13. The starting system according to claim 8, characterized in that: The method of sequentially starting the proximal and distal motors of the large-capacity motor load power supply system includes: The rotor series resistance classification method is adopted to start the motor load in the grid in batches, including: First start the motor load in the local power supply system B in the large-capacity motor load power supply system, and then start the motor load in the local power supply system A in the large-capacity motor load power supply system.

14. The starting system according to claim 8, characterized in that: The motor load capacity PM and the flexible direct current capacity Pvsc of the large-capacity motor load power supply system satisfy the following: PM<0.5Pvsc.

15. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 7 is implemented.

16. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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