Converter station hierarchical simulation test system

Abstract

The present invention provides a hierarchical simulation test system for a converter station, comprising a large-step simulation device, a small-step simulation device, and a simulation server. The small-step simulation device is arranged at a project site, and is used to simulate a DC device or system to be simulated, and is connected to the engineering equipment that needs to participate in the simulation; the large-step simulation device is arranged at a simulation center, and is used to simulate an AC system to be simulated; the simulation server is arranged at the simulation center, and is used for modeling, signal processing, and waveform display, wherein, in order to ensure real-time performance, the DC device or system with a fast change speed, high communication requirements, and needing to be connected to the engineering equipment is simulated by using a small-step simulation device arranged at the project site, and the AC device with a slow change speed and low communication requirements is simulated by using a large-step simulation device arranged at the simulation center, and there is no need to transport the engineering equipment at the project site to the simulation center over long distances.

Description

Technical Field

[0001] The invention relates to the field of power transmission, and in particular to a converter station hierarchical simulation test system. Background Art

[0002] Flexible DC transmission technology is a new type of transmission technology based on voltage source converters, self-shutoff devices and pulse width modulation (PWM) technology. This transmission technology has the advantages of being able to supply power to passive networks, no commutation failure, no need for communication between converter stations, and easy to form a multi-terminal DC system. Compared with the traditional thyristor-based current source DC transmission technology, flexible DC transmission technology has high controllability, convenient and environmentally friendly design and construction, small footprint, and no need for communication between converter stations. It has obvious advantages in renewable energy grid connection, distributed generation grid connection, island power supply, and urban power grid power supply. Flexible DC transmission has developed rapidly in recent years.

[0003] The half-bridge MMC converter is one of the main components of flexible DC transmission. Its main structure is as follows: Figure 1 As shown in the figure, the converter consists of three phase units, each of which includes two upper and lower bridge arms, and the bridge arm branches are composed of a large number of MMC submodules connected in series. Each MMC submodule consists of IGBT, capacitor, diode, thyristor and other components, and the capacitor is controlled by the on and off of the IGBT. The voltage of the entire branch is controlled by controlling the number and voltage of the MMC submodules in the phase unit.

[0004] The control and protection strategies and effects of flexible DC transmission can only be tested and verified through simulation. If pure digital simulation is performed, many engineering conditions and strategies can only be simplified or equivalent, which deviates greatly from the actual effects of the project. In order to ensure the test effect, mixed mechanical simulation is required.

[0005] When using mixed mechanical simulation, if the test equipment is moved to the project site, it is difficult to achieve due to the large number of test equipment, large size, high cost, easy damage during transportation, and high power supply requirements at the project site. Generally, the control and protection system joint debugging test is carried out in the laboratory before the project is put into operation or when the system is upgraded.

[0006] The existing testing method is to build a simulation environment and test system in the laboratory that is consistent with the on-site conditions; building the test environment requires transporting the equipment on the project site to the laboratory. The engineering equipment needs to occupy a large amount of experimental space, consumes a lot of manpower, material resources and time, and the workload is large and cumbersome. Transporting engineering equipment to the laboratory will inevitably lead to the suspension or delay of the project, causing economic losses.

[0007] The current practice is to transport a large number of equipment from the project site to the laboratory and build a simulation test system Summary of the invention

[0008] In view of the problems in the prior art, the present invention provides a converter station hierarchical simulation test system, which can at least partially solve the problems in the prior art.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] In a first aspect, a converter station hierarchical simulation test system is provided, comprising: a large step length simulation device, a small step length simulation device and a simulation server;

[0011] The large step length simulation device is communicatively connected with the small step length simulation device and the simulation server;

[0012] The small-step simulation device is set up at the engineering site, used to simulate the DC device or system to be simulated, and connected to the engineering equipment that needs to participate in the simulation;

[0013] The large-step simulation device is set up in the simulation center and is used to simulate the AC system to be simulated;

[0014] The simulation server is arranged in the simulation center and is used for modeling, signal processing and waveform display.

[0015] Furthermore, the small-step-size simulation device is a mobile simulator.

[0016] Further, the mobile simulator comprises: an MMC computing device and an interface device connected to the MMC computing device;

[0017] The MMC calculation device is used to calculate the MMC valve model, and the interface device is used to receive the collected analog quantity and digital quantity.

[0018] Furthermore, the small step length simulation device is generally connected to the flexible direct current control protection system through a valve control device, and is connected to other field devices according to experimental needs.

[0019] Furthermore, the large-step simulation device is a real-time digital simulator for model calculation, host computer communication and signal synchronization.

[0020] Furthermore, the converter station hierarchical simulation test system further includes: a first protocol conversion device and a second protocol conversion device;

[0021] The first protocol conversion device is arranged in the simulation center, connected to the large step length simulation device, and is used to receive the small step length simulation result and perform protocol conversion, and is used to send the large step length simulation result to the engineering site after performing protocol conversion;

[0022] The second protocol conversion device is arranged at the project site, connected to the small step simulation device, for receiving the large step simulation result and performing protocol conversion, and for sending the small step simulation result to the simulation center after performing protocol conversion.

[0023] Furthermore, the first protocol conversion device and the second protocol conversion device are connected via a 5G mobile network communication.

[0024] Furthermore, the first protocol conversion device and the second protocol conversion device are connected via optical fiber communication.

[0025] The converter station hierarchical simulation test system provided by the present invention comprises: a large-step-length simulation device, a small-step-length simulation device and a simulation server; the large-step-length simulation device is communicatively connected with the small-step-length simulation and the simulation server. The small-step simulation device is set at the project site, used to simulate the DC device or system to be simulated, and connected to the engineering equipment that needs to participate in the simulation; the large-step simulation device is set at the simulation center, used to simulate the AC system to be simulated; the simulation server is set in the simulation center, used for modeling, signal processing and waveform display, wherein, in order to ensure real-time performance, the DC device or system with a faster change speed, higher communication requirements and need to be connected to the engineering equipment is simulated by using the small-step simulation device set at the project site, and the AC device with a slower change speed and lower communication requirements is simulated by using the large-step simulation device set at the simulation center. Since the small-step simulation device is small in size, small in board, and can work with AC power, the small-step simulation device can be set at the project site, and there is no need to transport the engineering equipment at the project site to the simulation center over long distances. The large-step simulation device with large size, high cost and high power requirements is set at the simulation center. On the basis of not moving the test equipment to the project site, the control and protection strategy of flexible DC transmission is tested and simulated, and the workload is reduced while ensuring the simulation effect. It is simple and convenient.

[0026] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0028] Figure 1It is a structural diagram of a half-bridge MMC converter in an existing flexible DC transmission system;

[0029] Figure 2 An architecture diagram of a converter station hierarchical simulation test system according to an embodiment of the present invention is shown;

[0030] Figure 3 A simulation model of a large-step-length simulation device in an embodiment of the present invention is shown;

[0031] Figure 4 The simulation model of the small step length simulation device in the embodiment of the present invention is shown;

[0032] Figure 5 An architecture diagram of another converter station hierarchical simulation test system according to an embodiment of the present invention is shown;

[0033] Figure 6 The overall network architecture of a system according to an embodiment of the present invention is shown;

[0034] Figure 7 The working principle of the mobile simulator in the embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0036] The detailed features and advantages of the present invention are described in detail in the following embodiments, and the contents are sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the contents, claims and drawings disclosed in this specification, any person skilled in the art can easily understand the relevant purposes and advantages of the present invention. The following examples further illustrate the viewpoints of the present invention in detail, but do not limit the scope of the present invention in any viewpoint.

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] The existing solution of using laboratory joint debugging test scheme to simulate the converter station has simplified or equivalent many on-site environments, which deviates greatly from the actual effect of the project. Therefore, the existing test method is to build a simulation environment and test system in the laboratory that is consistent with the on-site conditions; to build the test environment, it is necessary to transport the equipment on the project site to the laboratory, or to reconfigure a set of control and protection devices in the laboratory that are the same as those on the project site, which is a large and cumbersome workload.

[0039] In order to at least partially solve the above-mentioned technical problems existing in the prior art, an embodiment of the present invention provides a converter station hierarchical simulation test system. To ensure real-time performance, a DC device or system with a fast changing speed, high communication requirements and need to be connected to engineering equipment is simulated by a small-step simulation device set up at the project site, and an AC device with a slow changing speed and low communication requirements is simulated by a large-step simulation device set up in a simulation center. There is no need to transport the engineering equipment at the project site to the simulation center over long distances, and the large-step simulation device with a large volume, high cost and high power supply requirements is set in the simulation center. Without moving the test equipment to the project site, the control and protection strategy of flexible DC transmission can be tested and simulated. On the basis of ensuring the simulation effect, the workload is reduced, and it is simple and convenient.

[0040] Figure 2 FIG. 4 shows an architecture diagram of a converter station hierarchical simulation test system according to an embodiment of the present invention; Figure 2 As shown, the converter station hierarchical simulation test system includes: a large step length simulation device 2, a small step length simulation device 5 and a simulation server 1;

[0041] The large step length simulation device 2 is communicatively connected with the small step length simulation device 5 and the simulation server 1;

[0042] The small step simulation device 5 is arranged at the engineering site, used to simulate the DC device or system to be simulated, and connected to the engineering equipment that needs to participate in the simulation;

[0043] The large step length simulation device 2 is arranged in the simulation center and is used to simulate the AC system to be simulated;

[0044] The simulation server 1 is arranged in the simulation center and is used for modeling, signal processing and waveform display.

[0045] Among them, the hierarchical real-time digital simulation test of the converter station is realized by combining the field and the laboratory. It is worth noting that the large step simulation equipment is mainly used to simulate the AC power grid equipment with a slow rate of change of electrical quantities. Its simulation model is as follows Figure 3 As shown; small step simulation equipment is mainly used to simulate power electronic equipment and other equipment with fast state and electrical quantity changes. Its simulation model is as follows Figure 4As shown in the figure, for a power grid with a converter station, a small step simulation is used for the converter and the AC equipment connected to it, and a large step simulation is used for other AC power grid equipment. Some data and signals can directly collect real data from the engineering site; data interaction between large-step simulation equipment and small-step simulation equipment can be carried out through a fast data transmission network. That is, the small-step simulation that needs to be connected to the engineering equipment is carried out at the engineering site. If data interaction with the engineering equipment is not required, then this part of the simulation content is still carried out in the simulation center.

[0046] In summary, the present invention uses the mobile small-step simulator to carry out field tests by combining the results of large-step simulation equipment and small-step simulation equipment and targeting the characteristics of different signals. The large-step simulator is used to obtain field data in the laboratory via a data transmission network to realize simulation. There is no need to move the equipment at the project site to the simulation center. Without moving the test equipment to the project site, the control and protection strategy of flexible direct current transmission can be tested and simulated. While ensuring the simulation effect, the workload is reduced, and the system is simple and convenient.

[0047] In an optional embodiment, the small-step-size simulation device is a mobile simulator.

[0048] Specifically, the mobile simulator may include: an MMC computing device and an interface device connected to the MMC computing device;

[0049] The MMC calculation device is used to calculate the MMC valve model, and the interface device is used to receive the collected analog quantities and digital quantities.

[0050] By adopting the small-step simulation device with the above structure, high-precision small-step simulation can be achieved, and the simulation effect can be further optimized.

[0051] In an optional embodiment, continue to see Figure 2 The small-step simulation device 5 is generally connected to the flexible direct current control protection system 7 through the valve control device 6, and is connected to other field devices 8 according to experimental needs.

[0052] In an optional embodiment, the large-step simulation device is a real-time digital simulator for performing model calculations, host computer communications, and signal synchronization.

[0053] In an alternative embodiment, see Figure 5 The converter station hierarchical simulation test system may further include: a protocol conversion device 3 and a protocol conversion device 4.

[0054] The protocol conversion device 3 is arranged in the simulation center, connected to the large step simulation device 2, and is used to receive the small step simulation results and perform protocol conversion, and is used to send the large step simulation results to the engineering site after protocol conversion;

[0055] The protocol conversion device 4 is arranged at the engineering site, connected to the small step simulation device 5, for receiving the large step simulation result and performing protocol conversion, and for sending the small step simulation result to the simulation center after performing protocol conversion.

[0056] Among them, by setting up a protocol conversion device to perform data transmission and reception and protocol conversion, the communication flexibility between the large-step-length simulation device and the small-step-length simulation device is improved.

[0057] In an optional embodiment, the protocol conversion device 3 and the protocol conversion device 4 can be connected via a 5G mobile network communication.

[0058] With the rapid development of communication technologies such as 5G and even 6G, the amount of data that can be transmitted per unit time is already large and stable, and the transmission rate can reach 100Mb or even faster. By using 5G mobile networks to transmit data, the real-time performance of large-step simulation equipment in acquiring data is improved, further optimizing the simulation effect.

[0059] In another optional embodiment, the protocol conversion device 3 and the protocol conversion device 4 may be connected to each other via cables, optical fibers, etc., so as to achieve fast data transmission.

[0060] It is worth noting that the converter station hierarchical simulation test system provided by the embodiment of the present invention can set up multiple mobile simulators at multiple sites, see Figure 6 , realize the networking of multiple sites, multiple mobile simulators and central simulation systems. The mutual networking can use the power private network or 5G communication network; if the 5G communication network is used to transmit data, it is necessary to add a 5G transmission module to the protocol conversion device. An interface device is set up near the control and protection equipment that needs to be connected. The mobile simulator should be connected to the interface device using optical fiber on site.

[0061] In addition, the converter station hierarchical simulation test system provided by the embodiment of the present invention can partially collect the real data and status of the primary equipment, see Figure 7, can better reflect the characteristics and action time of the on-site equipment, especially in the simulation of reproducing the accident scene or the situation where there are some new equipment with unclear characteristics on site. For example, add the DC circuit breaker to the mobile simulator, DC valve control, DC control, and DC protection links for overall closed-loop testing. In this way, after simulating the power grid fault, the overall action time of the protection device and the DC circuit breaker can be actually collected, including the actual input time, input status, exit time, exit status, etc. of each branch of the DC circuit breaker (current-carrying branch, transfer path, etc.) during the disconnection process. During the test, the status monitoring and response monitoring of the equipment can be added according to the test needs.

[0062] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0063] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0064] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0065] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A converter station hierarchical simulation test system, characterized in that: include: A large-step-length simulation device, a small-step-length simulation device, a simulation server, a first protocol conversion device, and a second protocol conversion device; The large-step-length simulation device is communicatively connected with the small-step-length simulation device and the simulation server; The small-step simulation device is arranged at the engineering site, used to simulate the DC device or system to be simulated, and connected to the engineering equipment that needs to participate in the simulation; The large-step simulation device is arranged in the simulation center and is used to simulate the AC system to be simulated; The simulation server is arranged in the simulation center and is used for modeling, signal processing and waveform display; The first protocol conversion device is arranged in the simulation center, connected to the large step-size simulation device, and is used to receive the small step-size simulation result and perform protocol conversion, and is used to send the large step-size simulation result to the engineering site after performing protocol conversion; The second protocol conversion device is arranged at the engineering site, connected to the small step simulation device, and is used to receive the large step simulation result and perform protocol conversion, and is used to send the small step simulation result to the simulation center after performing protocol conversion; The first protocol conversion device and the second protocol conversion device are connected via 5G mobile network communication or optical fiber communication; DC equipment or systems that change quickly, have high communication requirements and need to be connected to engineering equipment are simulated using small-step simulation equipment set up at the project site. AC equipment that changes slowly and has low communication requirements is simulated using large-step simulation equipment set up in the simulation center.

2. The converter station hierarchical simulation test system according to claim 1, characterized in that: The small-step-length simulation device is a mobile simulator.

3. The converter station hierarchical simulation test system according to claim 2, characterized in that: The mobile simulator comprises: an MMC computing device and an interface device connected to the MMC computing device; The MMC calculation device is used to calculate the MMC valve model, and the interface device is used to receive the collected analog quantities and digital quantities.

4. The converter station hierarchical simulation test system according to claim 1, characterized in that: The small step length simulation device is generally connected to the flexible direct current control protection system through a valve control device, and is connected to other field devices according to experimental needs.

5. The converter station hierarchical simulation test system according to claim 1, characterized in that: The large-step simulation device is a real-time digital simulator used for model calculation, host computer communication and signal synchronization.

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