A DC control protection test system and test method thereof

Abstract

The present invention discloses a DC control protection test system and a test method thereof. The system comprises a real-time simulator, an LCC control protection device, an LCC pulse trigger device, a VSC control protection device, a VSC submodule trigger device and a workstation; the real-time simulator is respectively connected to the first input / output end of the LCC control protection device, the first input / output end of the VSC control protection device, the first input / output end of the LCC pulse trigger device and the first input / output end of the VSC submodule trigger device; the second input / output end of the LCC control protection device is connected to the second input / output end of the LCC pulse trigger device; the second input / output end of the VSC control protection device is connected to the second input / output end of the VSC submodule trigger device; the workstation is respectively connected to the LCC control protection device and the VSC control protection device through a switch. The system provided by the present invention is simple, easy to operate, and low in cost, and can also test and study the key characteristics of the DC control protection device.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power control protection testing, and in particular to a direct current control protection testing system and a testing method thereof. Background Art

[0002] At present, two types of DC transmission technologies are mainly used in the field of DC transmission, namely LCC converter transmission technology and VSC converter transmission technology, as well as LCC and VSC hybrid converter charging. LCC transmission uses semi-controlled devices such as thyristors, which mainly transmit power by controlling the current on the DC line. It requires a large DC reactance on the DC side. VSC transmission uses fully controlled devices such as IGBTs, which mainly control the DC side voltage by controlling the opening and closing of the DC side submodules. Each submodule needs to be equipped with a large submodule capacitor. The control and protection system of each type of converter is relatively complex, and the system is controlled by a large number of control and protection cabinets. Not only is the system large and occupies a large area, but the cost is also high, and performance testing of the system is also time-consuming and labor-intensive. Summary of the invention

[0003] The purpose of the embodiment of the present invention is to provide a DC control protection test system and a test method thereof. The system is simple, easy to operate, and low-cost. It can not only achieve the same characteristics as the actual control protection device on site, but also test and study the key characteristics of the DC control protection device.

[0004] To achieve the above object, an embodiment of the present invention provides a DC control protection test system, which includes a real-time simulator, an LCC control protection device, an LCC pulse trigger device, a VSC control protection device, a VSC submodule trigger device and a workstation; wherein,

[0005] The first input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC control protection device, the second input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC control protection device, the input terminal of the real-time simulator is connected to the first input / output terminal of the LCC pulse trigger device, and the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device;

[0006] The second input / output terminal of the LCC control protection device is connected to the second input / output terminal of the LCC pulse trigger device;

[0007] The second input / output terminal of the VSC control protection device is connected to the second input / output terminal of the VSC submodule trigger device;

[0008] The workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through a switch.

[0009] Preferably, the workstation includes an operation workstation and a development workstation; wherein the operation workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through the switch, and the development workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through the switch.

[0010] Preferably, the input end of the real-time simulator is connected to the first input / output end of the LCC pulse trigger device through a cable and an interface card.

[0011] Preferably, the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device via an optical fiber.

[0012] Preferably, the second input / output end of the LCC control protection device is connected to the second input / output end of the LCC pulse trigger device through an optical fiber.

[0013] Preferably, the second input / output end of the VSC control protection device is connected to the second input / output end of the VSC submodule triggering device through an optical fiber.

[0014] Another embodiment of the present invention provides a test method of a DC control protection test system as described in any one of the above, comprising the following steps:

[0015] Build and run a primary model of DC transmission operation in a real-time simulator;

[0016] A master control station is set in the LCC control and protection device and the VSC control and protection device, and the control mode of each DC station is set to the automatic sequential control mode or the manual sequential control mode;

[0017] Adjust the DC field grounding mode to the preset operating mode;

[0018] adjusting the model to a bipolar unlocked operating mode for rated power operation;

[0019] Changing the operating condition of a primary model in the real-time simulator to perform fault simulation;

[0020] Responses of the LCC control and protection device and the VSC control and protection device are obtained.

[0021] Compared with the prior art, the DC control protection test system and test method provided in the embodiment of the present invention streamlines the complex converter test panel cabinet on site, retains the core and key parts such as the LCC control protection device and the VSC control protection device, and then matches them with a real-time simulator and a workstation, so as to achieve the same characteristics as the actual control protection device on site and test and study the key characteristics of the DC control protection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a DC control protection test system provided by an embodiment of the present invention;

[0023] Figure 2 The present invention is a flowchart of a test method for a DC control protection test system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 , is a structural diagram of a DC control protection test system provided by an embodiment of the present invention, the system includes a real-time simulator, an LCC control protection device, an LCC pulse triggering device, a VSC control protection device, a VSC submodule triggering device and a workstation; wherein,

[0026] The first input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC control protection device, the second input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC control protection device, the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC pulse trigger device, and the fourth input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device;

[0027] The second input / output terminal of the LCC control protection device is connected to the second first input / output terminal of the LCC pulse trigger device;

[0028] The second input / output terminal of the VSC control protection device is connected to the second input / output terminal of the VSC submodule trigger device;

[0029] The workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through a switch.

[0030] It should be noted that at present, two types of DC transmission technologies are mainly used in the field of DC transmission, namely LCC converter transmission technology and VSC converter transmission technology, as well as LCC and VSC hybrid converter charging. Among them, the full name of LCC is Line Commutated Converter, also known as phase-controlled converter, and the full name of VSC is Voltage Source Converter, also known as voltage source converter. The control and protection system of each type of converter is relatively complex, and the system is controlled by a large number of control and protection cabinets, which is costly. Taking the Yunnan asynchronous interconnection project as an example, the project involves 2 conventional DC transmission units and 1 flexible DC transmission unit, with 200 cabinets, and the system is extremely large and complex.

[0031] In view of the existing complex test panels on site, the present invention simplifies the system. Specifically, the DC control protection test system includes a real-time simulator, an LCC control protection device, an LCC pulse trigger device, a VSC control protection device, a VSC submodule trigger device and a workstation. The real-time simulator is used to simulate primary equipment in an actual power grid, such as converter valves, transformers, DC lines, etc. The LCC control protection device, the LCC pulse trigger device, the VSC control protection device and the VSC submodule trigger device together constitute a control protection device, which is used to simulate a control protection system in an actual power grid. The workstation is used to develop a control protection system program and run the control protection system program. Among them,

[0032] The first input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC control protection device, the second input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC control protection device, the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC pulse trigger device, and the fourth input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device;

[0033] The second input / output end of the LCC control protection device is connected to the second input / output end of the LCC pulse trigger device; the second input / output end of the VSC control protection device is connected to the second input / output end of the VSC submodule trigger device.

[0034] The workstation is connected to the third input / output terminal of the LCC control protection device and the third input / output terminal of the VSC control protection device through the switch. The workstation is connected to the system network through the switch. In addition to the switch, the system network can also be connected through other communication methods.

[0035] The embodiment of the present invention provides a DC control protection test system, which replaces the complex control protection panel cabinets of the LCC converter and the VSC converter in the actual power grid project by using a simulator, an LCC control protection device, an LCC pulse triggering device, a VSC control protection device, a VSC submodule triggering device and a workstation, so that the obtained simulation system structure is streamlined, retaining the core and key parts, and can achieve the same characteristics as the actual control protection device on site, thereby testing and studying the key characteristics of the DC control protection device.

[0036] As an improvement of the above scheme, the workstation includes an operation workstation and a development workstation; wherein the operation workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through the switch, and the development workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through the switch.

[0037] Specifically, the workstation includes an operation workstation and a development workstation; wherein the operation workstation is connected to the third input / output terminal of the LCC control protection device and the third input / output terminal of the VSC control protection device through a switch, and the development workstation is connected to the third input / output terminal of the LCC control protection device and the third input / output terminal of the VSC control protection device through a switch. The operation workstation is used to run the control protection system program; the development workstation is used to develop the control protection system program, and both are indispensable. In addition, network cables are also used to connect the workstation to the switch, and the switch to the LCC control protection device and the VSC control protection device.

[0038] As an improvement of the above solution, the input end of the real-time simulator is connected to the first input / output end of the LCC pulse trigger device through a cable and an interface card.

[0039] Specifically, the input end of the real-time simulator is connected to the first input / output end of the LCC pulse trigger device through a cable and an interface card, and is used to receive a pulse signal sent by the LCC pulse trigger device to control the simulation model of the real-time simulator.

[0040] As an improvement of the above solution, the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device through an optical fiber.

[0041] Specifically, the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device through an optical fiber, and is used to receive the pulse signal sent by the VSC submodule trigger device, and at the same time send each submodule voltage to the VSC submodule trigger device.

[0042] As an improvement of the above solution, the second input / output end of the LCC control and protection device is connected to the second input / output end of the LCC pulse trigger device through an optical fiber.

[0043] Specifically, the second input / output end of the LCC control and protection device is connected to the second input / output end of the LCC pulse trigger device through an optical fiber. In this way, the LCC pulse trigger device can send a simulated thyristor conduction state signal to the LCC control and protection device. The thyristor conduction state signal is to indicate that the thyristor has been reliably triggered; the LCC pulse trigger device can also receive the trigger angle sent by the LCC control and protection device, and convert the trigger angle into a trigger pulse signal for sending down.

[0044] As an improvement of the above solution, the second input / output end of the VSC control protection device is connected to the second input / output end of the VSC submodule triggering device through an optical fiber.

[0045] Specifically, the second input / output end of the VSC control and protection device is connected to the second input / output end of the VSC sub-module trigger device through an optical fiber. In this way, the VSC sub-module trigger device can send its own operating status and sub-module voltage to the VSC control and protection device, and it can also receive the modulation wave and unlocking signal of the VSC control and protection device.

[0046] Another embodiment of the present invention provides a test method of the DC control protection test system as described in any of the above embodiments, comprising the following steps:

[0047] Build and run a primary model of DC transmission operation in a real-time simulator;

[0048] A master control station is set in the LCC control and protection device and the VSC control and protection device, and the control mode of each DC station is set to the automatic sequential control mode or the manual sequential control mode;

[0049] Adjust the DC field grounding mode to the preset operating mode;

[0050] adjusting the model to a bipolar unlocked operating mode for rated power operation;

[0051] Changing the operating condition of a primary model in the real-time simulator to perform fault simulation;

[0052] Responses of the LCC control and protection device and the VSC control and protection device are obtained.

[0053] See also Figure 2 , is a flow chart of a test method of a DC control protection test system provided by this embodiment of the present invention, comprising Figure 2 It can be seen that the specific steps are as follows:

[0054] Build and run a primary model of DC transmission operation in a real-time simulator;

[0055] A master control station is set in the control and protection system, that is, a master control station is set in the LCC control and protection device and the VSC control and protection device, and the control mode of each DC station is set to the automatic sequential control mode or the manual sequential control mode;

[0056] Adjust the DC field grounding mode to the preset operating mode, such as the double-polarized return mode.

[0057] Adjusting the model to the bipolar unlocking operation mode is essentially adjusting the operation state of the operating valve group to the bipolar unlocking operation mode for rated power operation. In addition, the DC filter should be adjusted to the connection state, the DC voltage and current should be set to achieve full voltage of poles 1 and 2, and the communication between stations should be normal. The power transmission mode and set value should be set. The power transmission mode can be set to bipolar power control mode; set the tap control mode: automatic, angle control; set the reactive power control mode of each DC station: station 1 and station 2 are both Q mode; set the real-time simulator, i.e., RTDS, to the equivalent power supply mode.

[0058] The operating conditions of the primary model in the real-time simulator are changed to perform fault simulation. For example, a single-phase metal ground fault occurs in the AC system of station 1 in the real-time simulator, the voltage drops to 0%, the fault lasts for 700ms, and the real-time simulator records the waveform for 10s.

[0059] Obtain the responses of the LCC control and protection device and the VSC control and protection device, observe and record the responses, and complete the test.

[0060] In summary, a DC control protection test system and a test method thereof provided by an embodiment of the present invention streamlines the complex converter test panel cabinet at the actual site, retains the core and key parts such as the LCC control protection device and the VSC control protection device, and then matches them with a real-time simulator and a workstation, so as to achieve the same characteristics as the actual control protection device at the site, and can also test and study the key characteristics of the DC control protection device.

[0061] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A test method based on a DC control protection test system, characterized in that: The DC control protection test system includes a real-time simulator, an LCC control protection device, an LCC pulse trigger device, a VSC control protection device, a VSC submodule trigger device and a workstation; wherein, The first input / output terminal of the real-time simulator is connected to the first input / output terminal of the LCC control protection device, the second input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC control protection device, the input terminal of the real-time simulator is connected to the first input / output terminal of the LCC pulse trigger device, and the third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device; The second input / output terminal of the LCC control protection device is connected to the second input / output terminal of the LCC pulse trigger device; The second input / output terminal of the VSC control protection device is connected to the second input / output terminal of the VSC submodule trigger device; The workstation is connected to the third input / output terminal of the LCC control and protection device and the third input / output terminal of the VSC control and protection device respectively through a switch; The workstation includes an operation workstation and a development workstation; wherein the operation workstation is connected to the third input / output terminal of the LCC control protection device and the third input / output terminal of the VSC control protection device through the switch, and the development workstation is connected to the third input / output terminal of the LCC control protection device and the third input / output terminal of the VSC control protection device through the switch; The test method comprises the following steps: Build and run a primary model of DC transmission operation in a real-time simulator; A master control station is set in the LCC control and protection device and the VSC control and protection device, and the control mode of each DC station is set to the automatic sequential control mode or the manual sequential control mode; Adjust the DC field grounding mode to the preset operating mode; adjusting the model to a bipolar unlocked operating mode for rated power operation; Changing the operating condition of a primary model in the real-time simulator to perform fault simulation; Responses of the LCC control and protection device and the VSC control and protection device are obtained.

2. A test method based on a DC control protection test system as claimed in claim 1, characterized in that: The input end of the real-time simulator is connected to the first input / output end of the LCC pulse trigger device through a cable and an interface card.

3. A test method based on a DC control protection test system as claimed in claim 1, characterized in that: The third input / output terminal of the real-time simulator is connected to the first input / output terminal of the VSC submodule trigger device through an optical fiber.

4. A test method based on a DC control protection test system as claimed in claim 1, characterized in that: The second input / output end of the LCC control protection device is connected to the second input / output end of the LCC pulse trigger device through an optical fiber.

5. A test method based on a DC control protection test system as claimed in claim 1, characterized in that: The second input / output end of the VSC control protection device is connected to the second input / output end of the VSC submodule triggering device through an optical fiber.

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