Method and device for obtaining wind power transmission stability limit

Abstract

The application discloses a method and device for obtaining a wind power sending stability limit, and the method comprises the following steps: obtaining power operation data of a wind-thermal bundled external sending system, and constructing a simulation model in a real-time simulator, wherein the simulation model comprises a wind turbine generator and a thermal turbine generator; when the wind power is fully generated, a first test environment is constructed, and a wind power output stability limit test is performed on the thermal turbine generator; and when the thermal power is fully generated, a second test environment is constructed, and a thermal power output stability limit test is performed on the wind turbine generator; and the results of the two stability limit tests are combined as the stability limit of the wind-thermal bundled external sending system when the wind power is sent. It can be seen that by constructing different test conditions, accurately simulating the response characteristics of the actual control wind-thermal bundled external sending system, and performing corresponding output stability limit tests on the thermal turbine generator and the wind turbine generator, the wind power sending dynamic instability boundary when the wind power is fully generated and the thermal power is fully generated can be obtained, so that the risk of system dynamic power angle instability can be accurately investigated.

Description

Technical Field

[0001] This application relates to the field of wind and thermal power generation simulation, and more specifically, to a method and apparatus for obtaining the stable limit of wind power transmission. Background Technology

[0002] In recent years, with the continuous increase in electricity consumption, wind power development has been vigorously promoted, and its adoption rate has significantly increased. Wind-thermal power bundling transmission is the main method for large-scale centralized transmission of wind power, effectively solving the problem of the inverse distribution of energy reserves and load demand. The working mode of the wind-thermal power bundling transmission system is to collect wind power generated by wind farms and thermal power generated by thermal power plants at a wind-thermal power bundling station, bundle the wind and thermal power, and then transmit the bundled electricity to the main grid via an AC transmission channel. When the wind-thermal power bundling transmission system transmits through the AC channel, if the active power of the AC transmission channel is too high, a dynamic power angle instability may occur in the wind-thermal power bundling transmission system after a fault trip of the AC transmission line.

[0003] Traditional methods for calculating the stability limits of power grids are mostly based on electromechanical transient simulation or electromagnetic transient simulation software. The simulation models produced differ significantly from the actual response characteristics of the wind-thermal bundled power transmission system. Therefore, it is impossible to accurately simulate and calculate the operation and control characteristics of wind power to determine the stability limits of generator output and renewable energy output, and thus it is impossible to accurately determine the risk of dynamic power angle instability of the system.

[0004] How to determine the stable limit of wind power transmission in a combined wind and thermal power transmission system and accurately identify the risk of dynamic power angle instability in the system are issues that need attention. Summary of the Invention

[0005] In view of the above problems, this application is made to provide a method and apparatus for obtaining the stability limit of wind power transmission, so as to improve the output certainty of the wind-thermal bundled AC transmission system.

[0006] To achieve the above objectives, the following specific solutions are proposed:

[0007] A method for obtaining the stable limit of wind power transmission is applied to the scheduling processor in a wind power testing system. The wind power testing system includes a real-time simulator and the scheduling processor, and the scheduling processor is connected to the real-time simulator to control the real-time simulator.

[0008] The method includes:

[0009] The power operation data of the wind-fired power transmission system is acquired, and based on the power operation data, a simulation model of the wind-fired power transmission system is constructed in the real-time simulator. The simulation model includes wind turbines and thermal power units.

[0010] When the simulation model reaches full wind power generation, a first test environment for wind power output stability limit test is constructed, and the thermal power unit is subjected to wind power output stability limit test under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0011] When the simulation model reaches full thermal power generation, a second test environment for thermal power output stability limit test is constructed, and the wind turbine is subjected to thermal power output stability limit test under the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0012] The dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation is combined with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and this combination is used as the stability limit of the wind-thermal bundled transmission system when transmitting wind power.

[0013] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0014] The first test environment for constructing the wind power output stability limit test includes:

[0015] Set the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device;

[0016] Set the output power of the thermal power unit to the minimum operating power of the thermal power unit;

[0017] The operating power of the wind farm dynamic reactive power compensation protection device is set to the rated power of the wind farm dynamic reactive power compensation protection device.

[0018] Optionally, under the first test environment, a wind power output stability limit test is performed on the thermal power unit to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation, including:

[0019] In the first test environment, the output power of AC line B under AC line A with the AC transmission channel disconnected is obtained. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-fired power bundling station in the simulation model and the main grid in the simulation model. The wind-fired power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station.

[0020] Determine the damping ratio of AC line B based on its output power;

[0021] Determine whether the damping ratio is greater than a preset damping ratio threshold;

[0022] If so, the output power of the thermal power unit is increased according to a preset ratio to obtain a new output power of the thermal power unit;

[0023] Based on the output power of the new thermal power unit, the first test environment is updated to obtain a new first test environment;

[0024] After a preset first duration, the connection of AC line A is restored, and the process returns to the step of obtaining the output power of AC line B when AC line A in the simulation model is disconnected in the first test environment.

[0025] If not, determine the output power of the thermal power unit as such, and the simulation model reaches the dynamic instability boundary of wind power transmission when the wind power is at full capacity.

[0026] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0027] The second test environment for constructing the thermal power output stability limit test includes:

[0028] Set the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device;

[0029] The output power of the thermal power unit is set to the maximum operating power of the thermal power unit;

[0030] The operating power of the wind farm dynamic reactive power compensation protection device is set to the rated power of the wind farm dynamic reactive power compensation protection device.

[0031] Optionally, under the second test environment, a thermal power output stability limit test is performed on the wind turbine to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, including:

[0032] In the second test environment, the output power of AC line B under AC line A with the AC transmission channel disconnected is obtained. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-fired power bundling station in the simulation model and the main grid in the simulation model. The wind-fired power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station.

[0033] Determine the damping ratio of AC line B based on its output power;

[0034] Determine whether the damping ratio is greater than a preset damping ratio threshold;

[0035] If so, the output power of the wind turbine is increased according to a preset ratio to obtain a new output power of the wind turbine;

[0036] After a preset second duration, the connection of AC line A is restored, and the process returns to the step of obtaining the output power of AC line B when AC line A in the simulation model is disconnected in the second test environment.

[0037] If not, determine the output power of the wind turbine unit as the dynamic instability boundary of wind power transmission when the thermal power is at full capacity.

[0038] A device for obtaining the stable limit of wind power transmission is applied to the scheduling processor in a wind power testing system. The wind power testing system includes a real-time simulator and the scheduling processor, and the scheduling processor is connected to the real-time simulator to control the real-time simulator.

[0039] The device includes:

[0040] A real-time simulation unit is used to acquire power operation data of the wind-fired power transmission system and, based on the power operation data, construct a simulation model of the wind-fired power transmission system in the real-time simulator. The simulation model includes wind turbine units and thermal power units.

[0041] The wind power stability test unit is used to construct a first test environment for wind power output stability limit test when the simulation model reaches full wind power generation, and to conduct wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0042] The thermal power stability test unit is used to construct a second test environment for thermal power output stability limit test when the simulation model reaches full thermal power generation, and to conduct thermal power output stability limit test on the wind turbine in the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0043] The stability limit determination unit is used to combine the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and use it as the stability limit of the wind-thermal bundled transmission system when transmitting wind power.

[0044] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0045] The wind power stability testing unit constructs the first test environment for wind power output stability limit testing, including:

[0046] The wind power stability test unit sets the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device.

[0047] The wind power stability test unit sets the output power of the thermal power unit to the minimum operating power of the thermal power unit.

[0048] The wind power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0049] Optionally, the wind power stability testing unit performs a wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation, including:

[0050] Under the first test environment, the wind power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal bundled collection station in the simulation model and the main grid in the simulation model. The wind-thermal bundled collection station is connected to the thermal power unit and is connected to the wind power unit through the wind power collection station.

[0051] The wind power stability test unit determines the damping ratio of AC line B based on the output power of AC line B.

[0052] The wind power stability test unit determines whether the damping ratio is greater than a preset damping ratio threshold. If so, it increases the output power of the thermal power unit according to a preset ratio to obtain a new output power of the thermal power unit. Based on the new output power of the thermal power unit, it updates the first test environment to obtain a new first test environment. After a preset first time period, it restores the connection of AC line A and returns to the first test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, it determines that the output power of the thermal power unit is the same as the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0053] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0054] The thermal power stability testing unit constructs a second test environment for the thermal power output stability limit test, including:

[0055] The thermal power stability test unit sets the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device.

[0056] The thermal power stability test unit sets the output power of the thermal power unit to the maximum operating power of the thermal power unit.

[0057] The thermal power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0058] Optionally, the thermal power stability testing unit performs a thermal power output stability limit test on the wind turbine under the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, including:

[0059] Under the second test environment, the thermal power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal power bundling station in the simulation model and the main grid in the simulation model. The wind-thermal power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station.

[0060] The thermal power stability test unit determines the damping ratio of AC line B based on the output power of AC line B.

[0061] The thermal power stability test unit determines whether the damping ratio is greater than the preset damping ratio threshold. If so, it increases the output power of the wind turbine according to the preset ratio to obtain the new output power of the wind turbine. After a preset second time period, it restores the connection of AC line A and returns to the second test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, it determines that the output power of the wind turbine is the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0062] Using the above technical solution, this application acquires the power operation data of the wind-thermal power transmission bundled system and, based on the power operation data, constructs a simulation model of the wind-thermal power transmission bundled system in the real-time simulator. The simulation model includes wind turbine units and thermal power units. When the simulation model reaches full wind power generation, a first test environment for wind power output stability limit testing is constructed. Under the first test environment, the thermal power units are subjected to wind power output stability limit testing to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation. When the simulation model reaches full thermal power generation, a second test environment for thermal power output stability limit testing is constructed. Under the second test environment, the wind turbine units are subjected to thermal power output stability limit testing to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation. The dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation is combined with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation to serve as the stability limit of the wind-thermal power transmission bundled system during wind power transmission. Therefore, by constructing different test conditions, the response characteristics of the actual controlled wind and thermal power bundled transmission system can be accurately simulated. Corresponding output stability limit tests can be conducted on thermal power units and wind power units to obtain the dynamic instability boundary of wind power transmission when wind power is at full capacity and thermal power is at full capacity. This allows for the accurate identification of the risk of dynamic power angle instability in the system. Attached Figure Description

[0063] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0064] Figure 1 A system architecture diagram for obtaining the stable limit of wind power transmission provided in the embodiments of this application;

[0065] Figure 2 A schematic diagram of a process for obtaining the stable limit of wind power transmission provided in an embodiment of this application;

[0066] Figure 3 A simulation model diagram of a wind and fire bundling and delivery system provided in this application embodiment;

[0067] Figure 4 Another system architecture diagram for obtaining the stable limit of wind power transmission provided in the embodiments of this application;

[0068] Figure 5 This is a schematic diagram of a device for obtaining the stability limit of wind power transmission, provided in an embodiment of this application. Detailed Implementation

[0069] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] Figure 1 An optional system architecture for obtaining the stable limit of wind power transmission, as provided in the embodiments of this application, is as follows: Figure 1 As shown, the system architecture may include a scheduling processor and a real-time simulator.

[0071] Both the scheduling processor and the real-time simulator can be applied to the wind power testing system. The scheduling processor is connected to the real-time simulator to control the real-time simulator.

[0072] based on Figure 1 The system architecture shown in this application can be implemented based on a scheduler. Figure 2 The method for obtaining the wind power transmission stability limit of this application may include the following steps:

[0073] Step S110: Obtain the power operation data of the wind-fire bundled transmission system, and based on the power operation data, construct a simulation model of the wind-fire bundled transmission system in the real-time simulator.

[0074] The simulation model may include wind turbines and thermal power units. The wind turbines in the simulation model can be used to simulate wind power generation, and the thermal power units in the simulation model can be used to simulate thermal power generation.

[0075] Specifically, the power operation data of the wind-fire bundled transmission system can be measured in real time in advance. The real-time simulator can have a software interactive interface. The scheduling processor can schedule the real-time simulator to run based on the power operation data, and make the real-time simulator simulate the simulation model according to the power operation data.

[0076] For example Figure 3Wind turbines can transmit their generated power to the corresponding wind power collection station of the wind farm, and then to the wind-fired power bundling collection station. Thermal power units can transmit their generated power to the aforementioned wind-fired power bundling collection station. The wind-fired power bundling collection station can transmit the power to the main grid via an AC transmission channel. This AC transmission channel can consist of AC line A, AC line B, and AC line C.

[0077] Step S120: When the simulation model reaches full wind power generation, construct a first test environment for wind power output stability limit test, and conduct wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0078] Specifically, full wind power generation can indicate that the output of wind turbine units has reached the upper limit. The scheduling processor can set the output of wind turbine units in the simulation model to achieve full wind power generation. The dynamic instability boundary of wind power transmission when the wind power is fully generated can represent the maximum limit of the output of thermal power units when the wind power is dynamically transmitted.

[0079] It is understandable that when the simulation model of the wind-thermal bundled transmission system reaches full wind power generation, continuing to generate electricity will likely lead to instability in wind power transmission. Based on this, when the simulation model reaches full wind power generation, in order to explore the instability boundary, the first test environment for the wind power output stability limit test can be set up, and the wind power output stability limit test can be performed on the thermal power unit to obtain the maximum limit of the thermal power unit output when the wind power is fully generated.

[0080] Step S130: When the simulation model reaches full thermal power generation, construct a second test environment for thermal power output stability limit test, and conduct thermal power output stability limit test on the wind turbine in the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0081] Specifically, full thermal power generation can indicate that the output of thermal power units has reached its upper limit. The scheduling processor can set the output of thermal power units in the simulation model to achieve full thermal power generation. The dynamic instability boundary of wind power transmission when thermal power is at full capacity can represent the maximum limit of the output of wind power units when dynamic wind power is transmitted.

[0082] It is understandable that when the simulation model of the wind-thermal power transmission system reaches full thermal power generation, if power generation continues, it will likely lead to instability in wind power transmission. Based on this, when the simulation model reaches full thermal power generation, in order to explore the instability boundary, a second test environment for the wind power output stability limit test can be set up, and the wind turbine can be subjected to the thermal power output stability limit test to obtain the maximum limit of the wind turbine output when the thermal power is at full capacity.

[0083] Step S140: Combine the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and use the combination as the stability limit of the wind-thermal bundled transmission system when transmitting wind power.

[0084] The method for obtaining the stability limit of wind power transmission provided in this embodiment uses a real-time simulator to simulate a model of the wind-thermal bundled transmission system. The parameters of the simulation model are adjusted in the real-time simulator to accurately simulate the response characteristics of the actual control of the wind-thermal bundled transmission system. The stability limit test of wind power output is performed on the thermal power unit and the stability limit test of thermal power output is performed on the wind power unit. The dynamic instability boundary of wind power transmission under full wind power generation and full thermal power generation is obtained, and the stability limit of the wind-thermal bundled transmission system when transmitting wind power is obtained. Thus, the risk of dynamic power angle instability of the system can be accurately identified.

[0085] In some embodiments of this application, considering the need to protect the circuit of the simulation model when constructing the first test environment, protection parameters are set. In these embodiments, Figure 1 In addition to the above, it can also include wind turbine converter protection devices and wind farm dynamic reactive power compensation protection devices, such as Figure 4 As shown, the scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0086] Based on this, the process of constructing the first test environment for the wind power output stability limit test mentioned in the above embodiments is described, which may include:

[0087] S1. Set the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device.

[0088] Specifically, the maximum active power of the wind turbine converter protection device can be the upper limit of the operating power of the wind turbine converter protection device.

[0089] Understandably, the information of the first test environment is required by the simulation model in the real-time simulator, so the information of the maximum active power of the wind turbine converter protection device needs to be transmitted to the real-time simulator.

[0090] For example Figure 4 The wind turbine converter protection device can transmit the maximum active power to the real-time simulator through the signal input board, and can also receive feedback information from the real-time simulator through the signal output board.

[0091] S2. Set the output power of the thermal power unit to the minimum operating power of the thermal power unit.

[0092] It is understandable that the greater the dynamic power output of wind power, the more likely the dynamic power output process is to become unstable. Therefore, before exploring the dynamic instability boundary of wind power transmission, the output power of the thermal power unit can be set to the minimum operating power of the thermal power unit, so as to gradually increase the output power of the thermal power unit and find the operating power when the dynamic instability of wind power transmission occurs.

[0093] S3. Set the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0094] Specifically, the rated power of the dynamic reactive power compensation protection device for wind farms is the rated value of the reactive power of the dynamic reactive power compensation protection device for wind farms.

[0095] Understandably, the information of the first test environment is required by the simulation model in the real-time simulator, so the rated power information of the wind farm dynamic reactive power compensation protection device needs to be transmitted to the real-time simulator.

[0096] For example Figure 4 The dynamic reactive power compensation protection device for wind farms can transmit rated power to the real-time simulator through the signal input board, and can also receive feedback information from the real-time simulator through the signal output board.

[0097] The method for obtaining the wind power output stability limit provided in this embodiment constructs a first test environment for wind power output stability limit testing by setting the maximum active power of the wind turbine converter protection device, setting the minimum operating power of the thermal power unit, and setting the rated power of the wind farm dynamic reactive power compensation protection device.

[0098] In some embodiments of this application, the process of conducting a wind power output stability limit test on the thermal power unit under the first test environment mentioned in the above embodiments to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation is described. This process may include:

[0099] S1. Under the first test environment, obtain the output power of AC line B under AC line A with the AC output channel disconnected.

[0100] Specifically, disconnecting AC line A in the AC output channel can represent simulating a fault in the AC output channel. The scheduling processor can schedule the real-time simulator to enable an open-circuit fault in the AC output channel to disconnect AC line A.

[0101] S2. Determine the damping ratio of AC line B based on its output power.

[0102] Specifically, the damping ratio of the AC line B during operation of the target wind farm is calculated using the prony analysis module in the electromechanical transient calculation software.

[0103] S3. Determine whether the damping ratio is greater than the preset damping ratio threshold. If yes, proceed to S4; otherwise, proceed to S7.

[0104] Specifically, the preset damping ratio threshold can represent the critical damping value for wind power transmission instability. The preset damping ratio threshold can be customized, for example, 2%.

[0105] S4. Increase the output power of the thermal power unit according to a preset ratio to obtain a new output power of the thermal power unit.

[0106] Specifically, when the damping ratio of AC line B is not lower than the preset damping ratio threshold, it indicates that the simulation model has not yet experienced wind power transmission instability. The output power of the thermal power unit can be increased according to the preset ratio to obtain the new output power of the thermal power unit.

[0107] The preset ratio can represent the increase in the output power of the thermal power unit, and can be customized, for example, by increasing it by 5%.

[0108] S5. Based on the output power of the new thermal power unit, update the first test environment to obtain a new first test environment.

[0109] It is understandable that since the output power of the thermal power unit is set in the first test environment, the first test environment will also change when the output power of the thermal power unit is changed. Therefore, the test environment after increasing the output power of the thermal power unit can be determined as the new first test environment.

[0110] S6. After a preset first duration, restore the connection of the AC line A and return to execute S1.

[0111] Understandably, after setting the new output power of the thermal power unit, the simulation model can be allowed to run for a period of time until it stabilizes. Then, the AC line A connection can be restored, and the process can return to execute S1 to retest the wind power output stability limit of the thermal power unit.

[0112] S7. Determine the output power of the thermal power unit as follows: the simulation model reaches the dynamic instability boundary of wind power transmission when the wind power is at full capacity.

[0113] Specifically, when the damping ratio of AC line B is not lower than the preset damping ratio threshold, it indicates that the simulation model has experienced wind power transmission instability. The output power of the current thermal power unit can be determined as the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0114] The method for obtaining the stability limit of wind power transmission provided in this embodiment involves disconnecting AC line A under a first test environment, analyzing the damping ratio corresponding to the output power of AC line B, continuously increasing the output power of the thermal power unit until the output power of AC line B is lower than the preset damping ratio threshold, and then determining the current output power of the thermal power unit. The simulation model reaches the dynamic instability boundary of wind power transmission when the wind power is at full capacity, thus obtaining one of the limits of wind power transmission stability in the simulation model.

[0115] In some embodiments of this application, the process of constructing a second test environment for the thermal power output stability limit test mentioned in the above embodiments is described, and the process may include:

[0116] S1. Set the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device.

[0117] Specifically, the minimum active power of the wind turbine converter protection device can be the lower limit of the operating power of the wind turbine converter protection device.

[0118] Understandably, the information from the second test environment is required by the simulation model in the real-time simulator, therefore the minimum active power information of the wind turbine converter protection device needs to be transmitted to the real-time simulator.

[0119] S2. Set the output power of the thermal power unit to the maximum operating power of the thermal power unit.

[0120] Understandably, when thermal power plants are operating at full capacity, it is necessary to investigate the impact of wind turbines on the simulation model. Therefore, the output power of thermal power plants can be fixed at the maximum operating power.

[0121] S3. Set the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0122] Specifically, the rated power of the dynamic reactive power compensation protection device for wind farms is the rated value of the reactive power of the dynamic reactive power compensation protection device for wind farms.

[0123] Understandably, the information from the second test environment is required by the simulation model in the real-time simulator, therefore the rated power information of the wind farm dynamic reactive power compensation protection device needs to be transmitted to the real-time simulator.

[0124] The method for obtaining the wind power output stability limit provided in this embodiment constructs a second test environment for wind power output stability limit testing by setting the minimum active power of the wind turbine converter protection device, setting the maximum operating power of the thermal power unit, and setting the rated power of the wind farm dynamic reactive power compensation protection device.

[0125] In some embodiments of this application, the process of conducting a thermal power output stability limit test on the wind turbine under the second test environment, as mentioned in the above embodiments, to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation is described. This process may include:

[0126] S1. Under the second test environment, obtain the output power of AC line B under AC line A with the AC output channel disconnected.

[0127] Specifically, disconnecting AC line A in the AC output channel can represent simulating a fault in the AC output channel. The scheduling processor can schedule the real-time simulator to enable an open-circuit fault in the AC output channel to disconnect AC line A.

[0128] S2. Determine the damping ratio of AC line B based on its output power.

[0129] Specifically, the damping ratio of the AC line B during operation of the target wind farm is calculated using the prony analysis module in the electromechanical transient calculation software.

[0130] S3. Determine whether the damping ratio is greater than the preset damping ratio threshold. If yes, proceed to S4; otherwise, proceed to S6.

[0131] Specifically, the preset damping ratio threshold can represent the critical damping value for wind power transmission instability. The preset damping ratio threshold can be customized, for example, 2%.

[0132] S4. Increase the output power of the wind turbine according to a preset ratio to obtain a new output power of the wind turbine.

[0133] Specifically, when the damping ratio of AC line B is not lower than the preset damping ratio threshold, it indicates that the simulation model has not yet experienced wind power transmission instability. The output power of the wind turbine can be increased according to the preset ratio to obtain the output power of the thermal power unit.

[0134] The preset ratio can represent the increase in the output power of the thermal power unit, and can be customized, for example, by increasing it by 5%.

[0135] S5. After a preset second duration, restore the connection of the AC line A and return to execute S1.

[0136] Understandably, after setting the new output power of the wind turbine, the simulation model can be allowed to run for a period of time until it stabilizes. Then, the AC line A connection can be restored, and the process can return to execute S1 to retest the thermal power output stability limit of the wind turbine.

[0137] S6. Determine the output power of the wind turbine as the dynamic instability boundary of wind power transmission when the thermal power is at full capacity.

[0138] Specifically, when the damping ratio of AC line B is not lower than the preset damping ratio threshold, it indicates that the simulation model has experienced wind power transmission instability. The output power of the current wind turbine can be determined, and the simulation model reaches the dynamic instability boundary of wind power transmission when the thermal power is at full capacity.

[0139] The method for obtaining the stability limit of wind power transmission provided in this embodiment involves disconnecting AC line A under a second test environment, analyzing the damping ratio corresponding to the output power of AC line B, continuously increasing the output power of the wind turbine until the output power of AC line B is lower than the preset damping ratio threshold, and then determining the current output power of the wind turbine. The simulation model reaches the dynamic instability boundary of wind power transmission when the thermal power is at full capacity, thus obtaining one of the limits of wind power transmission stability in the simulation model.

[0140] The following describes the apparatus for obtaining the stable limit of wind power transmission provided in the embodiments of this application. The apparatus for obtaining the stable limit of wind power transmission described below can be referred to in correspondence with the method for obtaining the stable limit of wind power transmission described above.

[0141] See Figure 5 , Figure 5 This is a schematic diagram of a device for obtaining the stability limit of wind power transmission, as disclosed in an embodiment of this application.

[0142] like Figure 5 As shown, the device can be applied to a scheduling processor. The wind power testing system in which the scheduling processor is located also includes a real-time simulator and the scheduling processor. The scheduling processor is connected to the real-time simulator to control the real-time simulator.

[0143] The device includes:

[0144] The real-time simulation unit 11 is used to acquire the power operation data of the wind-fired power transmission system and, based on the power operation data, construct a simulation model of the wind-fired power transmission system in the real-time simulator. The simulation model includes wind turbine units and thermal power units.

[0145] The wind power stability test unit 12 is used to construct a first test environment for wind power output stability limit test when the simulation model reaches full wind power generation, and to conduct wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0146] The thermal power stability test unit 13 is used to construct a second test environment for thermal power output stability limit test when the simulation model reaches full thermal power generation, and to conduct thermal power output stability limit test on the wind turbine in the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0147] The stability limit determination unit 14 is used to combine the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and use it as the stability limit of the wind-thermal bundled transmission system when transmitting wind power.

[0148] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0149] The wind power stability testing unit constructs the first test environment for wind power output stability limit testing, including:

[0150] The wind power stability test unit sets the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device.

[0151] The wind power stability test unit sets the output power of the thermal power unit to the minimum operating power of the thermal power unit.

[0152] The wind power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0153] Optionally, the wind power stability testing unit performs a wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation, including:

[0154] Under the first test environment, the wind power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal bundled collection station in the simulation model and the main grid in the simulation model. The wind-thermal bundled collection station is connected to the thermal power unit and is connected to the wind power unit through the wind power collection station.

[0155] The wind power stability test unit determines the damping ratio of AC line B based on the output power of AC line B.

[0156] The wind power stability test unit determines whether the damping ratio is greater than a preset damping ratio threshold. If so, it increases the output power of the thermal power unit according to a preset ratio to obtain a new output power of the thermal power unit. Based on the new output power of the thermal power unit, it updates the first test environment to obtain a new first test environment. After a preset first time period, it restores the connection of AC line A and returns to the first test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, it determines that the output power of the thermal power unit is the same as the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation.

[0157] Optionally, the wind power testing system further includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device.

[0158] The thermal power stability testing unit constructs a second test environment for the thermal power output stability limit test, including:

[0159] The thermal power stability test unit sets the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device.

[0160] The thermal power stability test unit sets the output power of the thermal power unit to the maximum operating power of the thermal power unit.

[0161] The thermal power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

[0162] Optionally, the thermal power stability testing unit performs a thermal power output stability limit test on the wind turbine under the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, including:

[0163] Under the second test environment, the thermal power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal power bundling station in the simulation model and the main grid in the simulation model. The wind-thermal power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station.

[0164] The thermal power stability test unit determines the damping ratio of AC line B based on the output power of AC line B.

[0165] The thermal power stability test unit determines whether the damping ratio is greater than the preset damping ratio threshold. If so, it increases the output power of the wind turbine according to the preset ratio to obtain the new output power of the wind turbine. After a preset second time period, it restores the connection of AC line A and returns to the second test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, it determines that the output power of the wind turbine is the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation.

[0166] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0167] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0168] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for obtaining the stability limit of wind power transmission, characterized in that, A scheduling processor is used in a wind power testing system, the wind power testing system including a real-time simulator and the scheduling processor, the scheduling processor being connected to the real-time simulator to control the real-time simulator; The method includes: The power operation data of the wind-fired power transmission system is acquired, and based on the power operation data, a simulation model of the wind-fired power transmission system is constructed in the real-time simulator. The simulation model includes wind turbines and thermal power units. When the simulation model reaches full wind power generation, a first test environment for wind power output stability limit test is constructed, and the thermal power unit is subjected to wind power output stability limit test under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation. When the simulation model reaches full thermal power generation, a second test environment for thermal power output stability limit test is constructed, and the wind turbine is subjected to thermal power output stability limit test in the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation. The dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation is combined with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and this combination is used as the stability limit of the wind-thermal bundled transmission system when transmitting wind power. Under the first test environment, the wind power output stability limit test was conducted on the thermal power unit to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation, including: In the first test environment, the output power of AC line B under AC line A with the AC transmission channel disconnected is obtained. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-fired power bundling station in the simulation model and the main grid in the simulation model. The wind-fired power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station. Determine the damping ratio of AC line B based on its output power; Determine whether the damping ratio is greater than a preset damping ratio threshold; If so, the output power of the thermal power unit is increased according to a preset ratio to obtain a new output power of the thermal power unit; Based on the output power of the new thermal power unit, the first test environment is updated to obtain a new first test environment; After a preset first duration, the connection of AC line A is restored, and the process returns to the step of obtaining the output power of AC line B when AC line A in the simulation model is disconnected in the first test environment. If not, the output power of the thermal power unit is determined to be such that the simulation model reaches the dynamic instability boundary of wind power transmission when the wind power is at full capacity. Under the second test environment, the wind turbine was subjected to a thermal power output stability limit test to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, including: In the second test environment, the output power of AC line B under AC line A with the AC transmission channel disconnected is obtained. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-fired power bundling station in the simulation model and the main grid in the simulation model. The wind-fired power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station. Determine the damping ratio of AC line B based on its output power; Determine whether the damping ratio is greater than a preset damping ratio threshold; If so, the output power of the wind turbine is increased according to a preset ratio to obtain a new output power of the wind turbine; After a preset second duration, the connection of AC line A is restored, and the process returns to the step of obtaining the output power of AC line B when AC line A in the simulation model is disconnected in the second test environment. If not, determine the output power of the wind turbine unit as such, and the simulation model reaches the dynamic instability boundary of wind power transmission when the thermal power is at full capacity.

2. The method according to claim 1, characterized in that, The wind power testing system also includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device. The first test environment for constructing the wind power output stability limit test includes: Set the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device; Set the output power of the thermal power unit to the minimum operating power of the thermal power unit; The operating power of the wind farm dynamic reactive power compensation protection device is set to the rated power of the wind farm dynamic reactive power compensation protection device.

3. The method according to claim 1, characterized in that, The wind power testing system also includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device. The second test environment for constructing the thermal power output stability limit test includes: Set the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device; The output power of the thermal power unit is set to the maximum operating power of the thermal power unit; The operating power of the wind farm dynamic reactive power compensation protection device is set to the rated power of the wind farm dynamic reactive power compensation protection device.

4. A device for obtaining the stability limit of wind power transmission, characterized in that, The scheduling processor is applied to the wind power testing system described in the method for obtaining the wind power transmission stability limit as described in claim 1. The wind power testing system includes a real-time simulator and the scheduling processor, and the scheduling processor is connected to the real-time simulator to control the real-time simulator. The device includes: A real-time simulation unit is used to acquire power operation data of the wind-fired power transmission system and, based on the power operation data, construct a simulation model of the wind-fired power transmission system in the real-time simulator. The simulation model includes wind turbine units and thermal power units. The wind power stability test unit is used to construct a first test environment for wind power output stability limit test when the simulation model reaches full wind power generation, and to conduct wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation. The thermal power stability test unit is used to construct a second test environment for thermal power output stability limit test when the simulation model reaches full thermal power generation, and to conduct thermal power output stability limit test on the wind turbine in the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation. The stability limit determination unit is used to combine the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation with the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, and use it as the stability limit of the wind-thermal bundled transmission system when transmitting wind power.

5. The apparatus according to claim 4, characterized in that, The wind power testing system also includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device. The wind power stability testing unit constructs the first test environment for wind power output stability limit testing, including: The wind power stability test unit sets the operating power of the wind turbine converter protection device to the maximum active power of the wind turbine converter protection device. The wind power stability test unit sets the output power of the thermal power unit to the minimum operating power of the thermal power unit. The wind power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

6. The apparatus according to claim 4, characterized in that, The wind power stability testing unit performs a wind power output stability limit test on the thermal power unit under the first test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full wind power generation, including: Under the first test environment, the wind power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal bundled collection station in the simulation model and the main grid in the simulation model. The wind-thermal bundled collection station is connected to the thermal power unit and is connected to the wind power unit through the wind power collection station. The wind power stability test unit determines the damping ratio of AC line B based on the output power of AC line B. The wind power stability test unit determines whether the damping ratio is greater than a preset damping ratio threshold. If so, the wind power stability test unit increases the output power of the thermal power unit according to a preset ratio to obtain a new output power of the thermal power unit; The wind power stability test unit updates the first test environment based on the output power of the new thermal power unit to obtain a new first test environment. After a preset first time period, the wind power stability test unit restores the connection of AC line A and returns to the first test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, the wind power stability test unit determines the output power of the thermal power unit as follows: the simulation model reaches the dynamic instability boundary of wind power transmission when the wind power is at full capacity.

7. The apparatus according to claim 4, characterized in that, The wind power testing system also includes a wind turbine converter protection device and a wind farm dynamic reactive power compensation protection device. The scheduling processor is connected to the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device to control the wind turbine converter protection device and the wind farm dynamic reactive power compensation protection device. The thermal power stability testing unit constructs a second test environment for the thermal power output stability limit test, including: The thermal power stability test unit sets the operating power of the wind turbine converter protection device to the minimum active power of the wind turbine converter protection device. The thermal power stability test unit sets the output power of the thermal power unit to the maximum operating power of the thermal power unit. The thermal power stability test unit sets the operating power of the wind farm dynamic reactive power compensation protection device to the rated power of the wind farm dynamic reactive power compensation protection device.

8. The apparatus according to claim 4, characterized in that, The thermal power stability testing unit performs a thermal power output stability limit test on the wind turbine under the second test environment to obtain the dynamic instability boundary of wind power transmission when the simulation model reaches full thermal power generation, including: Under the second test environment, the thermal power stability test unit obtains the output power of AC line B under AC line A with the AC transmission channel disconnected. AC line A and AC line B are both AC transmission lines of the AC transmission channel in the simulation model. The AC transmission channel is used to connect the wind-thermal power bundling station in the simulation model and the main grid in the simulation model. The wind-thermal power bundling station is connected to the thermal power unit and is connected to the wind power unit through the wind power bundling station. The thermal power stability test unit determines the damping ratio of AC line B based on the output power of AC line B. The thermal power stability test unit determines whether the damping ratio is greater than a preset damping ratio threshold. If so, the thermal power stability test unit increases the output power of the wind turbine according to a preset ratio to obtain a new output power of the wind turbine; After a preset second time period, the thermal power stability test unit restores the connection of AC line A and returns to the second test environment to obtain the output power of AC line B when AC line A in the simulation model is disconnected. If not, the thermal power stability test unit determines the output power of the wind turbine as follows: the simulation model reaches the dynamic instability boundary of wind power transmission when the thermal power is at full capacity.

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