A power grid electromagnetic transient simulation method, device, system and storage medium

Abstract

The present application discloses a power grid electromagnetic transient simulation method, device, system and storage medium. In the simulation initialization stage, the load and power supply equipment in the power grid are grouped according to the active power control mode in the initialization stage. Each equipment component of the power grid is divided into a first equipment group or a second equipment group according to the state and control mode in the initialization stage. The electromagnetic transient simulation model is initialized and updated for each equipment component according to the power parameters of the two equipment groups. Then, based on the updated electromagnetic transient simulation model, electromagnetic transient simulation of the power grid is carried out to adjust the unbalanced power generated by the simulation model in the initialization stage. The simulation method proposed by the present invention reduces the dependence on the electromechanical transient simulation results, uses different initialization methods for different groups of equipment components, and greatly improves the simulation adaptability of the power grid including multiple types of power sources.

Description

Technical Field

[0001] The present invention belongs to the field of power grid simulation technology, and particularly relates to a power grid electromagnetic transient simulation method, device, system and storage medium. Background Art

[0002] Compared with electromechanical transient simulation, electromagnetic transient simulation cannot directly run to the steady state, but needs to start from the 0 moment. Devices such as generators, motors, and converters gradually adjust their powers according to the settings and finally reach the stable state.

[0003] In traditional electromagnetic transient simulation, the generator element is regarded as an infinite power source with a given phase angle and voltage amplitude at the initial stage. After the simulation starts for a period of time, the generator gradually releases its rotor and transforms into a normal generator element. The infinite power source responds quickly, and in the power grid model without considering converters, the simulation model can quickly reach the steady state. For the power grid model containing converters, the initialization processes of power electronic devices such as DC converters and new energy inverters are different from those of generators. The simulation of processes such as converter unlocking and filter input must be completed. The power rising speed is relatively slow, and it cannot quickly reach the power target value in the form of an ideal power source like a generator. The difference in the active power rising rate of components causes the power flow to deviate significantly from the normal steady-state value during the initialization process, and the abnormal power flow may cause voltage abnormalities, ultimately resulting in the inability of the converter component to complete the startup normally.

[0004] In addition, the existing electromagnetic transient simulation methods rely to a large extent on the results of electromechanical transient simulation, making it difficult to independently adjust the electromagnetic transient simulation model, and the simulation flexibility is poor. With the use of different forms of new energy in the power grid, the complexity of the initialization work of the electromagnetic transient simulation model increases, and the existing simulation methods no longer have universal applicability. Summary of the Invention

[0005] Based on this, the present invention aims to propose a power grid electromagnetic transient simulation method, device, system and storage medium, which consider different types of components in the simulation model and adopt different initialization methods for different types of generator components to reduce the dependence on the electromechanical transient simulation model.

[0006] In a first aspect, the present invention proposes a power grid electromagnetic transient simulation method, including:

[0007] Obtain the electromagnetic transient simulation model of the power grid;

[0008] Divide the device components in the electromagnetic transient simulation model into a first device group and a second device group according to the active power control mode in the simulation initialization stage;

[0009] Initialize each device component according to the power parameters of the first device group and the second device group and update the electromagnetic transient simulation model:

[0010] Perform electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

[0011] Furthermore, initializing each device element according to the power parameters of the first device group and the second device group includes:

[0012] Calculate the total power of the first device group during the initialization phase and the total power limit of the second device group;

[0013] Compare the total power of the first device group during the initialization phase with the total power limit of the second device group. If the total power of the first device group during the initialization phase is greater than the total power limit of the second device group, increase the number of device elements in the second device group and update the electromagnetic transient simulation model until the total power of the first device group during the initialization phase is less than the total power limit of the second device group;

[0014] Initialize each device element in the updated electromagnetic transient simulation model.

[0015] Furthermore, the device elements of the first device group include devices that directly control the active power according to the set active power target value during the initialization phase, and the device elements of the second device group include devices that take maintaining the grid frequency constant as the control target during the initialization phase.

[0016] Furthermore, when grouping for the first time, the generator elements in the electromagnetic transient simulation model are assigned to the first device group.

[0017] Furthermore, increasing the number of device elements in the second device group includes:

[0018] Increase the number of generator elements that take maintaining the grid frequency constant as the control target during the initialization phase.

[0019] Furthermore, the above simulation method further includes:

[0020] Set the power ramp rate and power target value of each device element in the first device group;

[0021] Calculate the total power of the first device group during the initialization phase according to the power ramp rate and power target value of each device element.

[0022] Furthermore, initialization includes:

[0023] Set the initial phase angles of the device elements in the second device group to be the same.

[0024] Furthermore, initialization also includes:

[0025] Let each device element of the first device group increase its power according to the set power ramp rate until it reaches the power target value;

[0026] When the active power of the generator element in the second device group reaches the power limit after startup, release the rotor of the generator element and put the governor element into the electromagnetic transient simulation model.

[0027] Furthermore, the above simulation method further includes:

[0028] Obtain the electromechanical transient simulation model of the power grid;

[0029] Perform power flow calculation on the power grid according to the electromechanical transient simulation model;

[0030] Establish an electromagnetic transient simulation model based on the calculation results of the power flow calculation.

[0031] In a second aspect, the present invention provides a power grid electromagnetic transient simulation device, including:

[0032] A model acquisition unit, configured to acquire the electromagnetic transient simulation model of the power grid;

[0033] A grouping unit, configured to divide the device elements in the electromagnetic transient simulation model into a first device group and a second device group according to the active power control mode in the simulation initialization stage;

[0034] An initialization unit, configured to initialize each device element according to the power parameters of the first device group and the second device group and update the electromagnetic transient simulation model;

[0035] A simulation execution unit, configured to perform electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

[0036] In a third aspect, the present invention provides a power grid electromagnetic transient simulation system, including a memory and a processor;

[0037] The memory is used to store programs;

[0038] The processor is used to call the program stored in the memory to execute the power grid electromagnetic transient simulation method provided in the first aspect embodiment and / or any possible implementation manner combined with the first aspect embodiment.

[0039] In a fourth aspect, the present invention provides a readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the power grid electromagnetic transient simulation method provided in the first aspect embodiment and / or any possible implementation manner combined with the first aspect embodiment.

[0040] From the above technical solutions, it can be seen that the present invention has the following beneficial effects:

[0041] A power grid electromagnetic transient simulation method, device, system and storage medium disclosed by the present invention. In the simulation initialization stage of the simulation method, loads and power supply devices in the power grid are grouped according to the active power control mode in the initialization stage. In a further embodiment, especially for generators, they can be regarded as the first device group or the second device group according to the state and control mode in the initialization stage. By comparing the total power of the two device groups with the power limit value, the number of devices with the control target of maintaining the power grid frequency constant is adjusted to regulate the unbalanced power generated in the initialization stage of the simulation model. The simulation method proposed by the present invention reduces the dependence on the results of electromechanical transient simulation, uses different initialization methods for different groups of device elements, and greatly improves the simulation adaptability of power grids including multiple types of power sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0043] Figure 1 The implementation process of a power grid electromagnetic transient simulation method provided by an embodiment of the present invention;

[0044] Figure 2 The implementation process of another power grid electromagnetic transient simulation method provided by an embodiment of the present invention;

[0045] Figure 3 The power grid topology structure diagram of Case 1 provided by an embodiment of the present invention;

[0046] Figure 4 The power grid topology structure diagram of Case 2 provided by an embodiment of the present invention;

[0047] Figure 5 The structural schematic diagram of a power grid electromagnetic transient simulation device provided by an embodiment of the present invention;

[0048] Figure 6 The architecture diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0050] In the electromagnetic transient simulation program, the initialization method of the synchronous generator is as follows: First, the generator element is regarded as an infinite power source with a given phase angle and voltage amplitude. After the simulation starts, after a period of time, the rotor, excitation control, speed control, etc. of the generator are gradually released. The generator changes from an infinite power source to a normal generator element. The active power at the moment when the generator is released is the initial state of the generator. Based on this, the initial value of the mechanical torque of the generator is set.

[0051] In the power grid model without considering the converter, the traditional electromagnetic transient simulation initialization method is as follows: First, a power flow calculation is performed using the electromechanical transient simulation model corresponding to the electromagnetic transient model to obtain the terminal voltage and rotor angle of the synchronous generator; then, in the electromagnetic transient simulation model, according to the power flow results obtained from the electromechanical transient simulation, the voltage amplitude and phase angle at the initial moment of each generator are set. After the electromagnetic transient simulation starts, the generator first operates in the form of an infinite power source. Since the voltage source amplitude and phase angle are consistent with the power flow results, the electromagnetic transient simulation model will obtain a stable state identical to the electromechanical transient simulation power flow results. At this time, the generator is released, and the infinite power source is converted into a generator, completing the initialization of the electromagnetic transient simulation model. Since the infinite power source responds quickly, the electromagnetic transient simulation model can quickly reach a steady state.

[0052] The initialization process of power electronic devices such as DC converters and new energy inverters is different from that of generators. It is necessary to complete the simulation of processes such as converter unlocking and filter input. The power rise speed is relatively slow, and it cannot quickly reach the power target value in the form of an ideal power source like a generator. In the power grid simulation model containing power electronic devices such as converters, components such as generators and loads can quickly reach the set power and enter a steady state, while the converter needs to slowly climb the power from 0. The power rise rates do not match, resulting in a large deviation of the power flow from the steady-state normal value during the initialization process. During this transition process, abnormal power flow may cause the converter to fail to start normally. Therefore, for a power grid containing power electronic devices such as converters, on the basis of the traditional electromagnetic transient simulation initialization method, a more scientific and reasonable initialization process design method is also required.

[0053] Term explanations related to the embodiments of the present invention:

[0054] Constant active power control device: It refers to a device that can directly control the active power according to the set active power target value, such as a load, a converter in the constant active power control mode, a generator after the rotor is released, and a converter in the constant DC voltage control mode.

[0055] Constant frequency control device: It refers to a device with the control objective of maintaining the power grid frequency constant, including an infinite power source, a generator before the rotor is released, and a converter in the constant frequency control mode.

[0056] The present invention illustrates a power grid electromagnetic transient simulation method, device, system and storage medium through the following embodiments, and different initialization methods are adopted for equipment components with different control modes to improve the universality of the electromagnetic transient simulation initialization method.

[0057] Refer to Figure 1 , an embodiment of the present invention provides an implementation process of a power grid electromagnetic transient simulation method, including the following steps:

[0058] Step S11. Obtain the electromagnetic transient simulation model of the power grid.

[0059] Specifically, the electromagnetic transient process refers to the transient electromagnetic phenomena that occur in the power system. When mutations or faults occur in the power system, the current and voltage will change instantaneously. Generally, the reasons for causing electromagnetic transients include switch operations, instantaneous load changes, short-circuit faults, etc. By simulating system faults through electromagnetic transient simulation, it is possible to timely conduct accident analysis on on-site protection devices and study the operation transients, resonance transients, fault transients, and control system transients of the power system, such as closing, reclosing, disconnection overvoltage, subsynchronous resonance of generators, short-circuit faults, and the interaction between the primary and secondary systems.

[0060] In some embodiments, step S11 includes:

[0061] Step S111. Obtain the electromechanical transient simulation model of the power grid.

[0062] Step S112. Conduct a power flow calculation on the power grid according to the electromechanical transient simulation model.

[0063] Step S113. Establish an electromagnetic transient simulation model according to the calculation results of the power flow calculation.

[0064] Specifically, a power flow calculation is performed using the electromechanical transient simulation model corresponding to the electromagnetic transient model to obtain the terminal voltage and rotor angle of the synchronous generator. In the electromagnetic transient simulation model, according to the power flow results obtained from the electromechanical transient simulation, the initial voltage amplitude and phase angle of each generator are set. After the electromagnetic transient simulation starts, the generator first operates in the form of an infinite power source. Since the voltage source amplitude and phase angle are consistent with the power flow results, the electromagnetic transient simulation model will obtain a stable state identical to the electromechanical transient simulation power flow results.

[0065] Step S12. Divide the equipment components in the electromagnetic transient simulation model into a first equipment group and a second equipment group according to the active power control mode in the simulation initialization stage.

[0066] Specifically, the loads and power supply equipment in the power grid are grouped according to the active power control mode in the initialization phase, and divided into a fixed active power control equipment group and a fixed frequency control equipment group. The output direction of the equipment in the fixed frequency control group must be consistent, that is, they can only all generate active power or all absorb active power.

[0067] Normally, fixed active power control equipment includes load, converter in fixed active power control mode, generator after releasing the rotor, and converter in fixed DC voltage control mode. The converter in fixed DC voltage control usually forms a two-terminal or multi-terminal DC with the converter in fixed active power control mode. After the power of other terminals is determined, the fixed DC voltage converter is also determined accordingly. Therefore, the converter in fixed DC voltage control mode is also regarded as fixed active power control equipment. Fixed frequency control equipment includes infinite power supply, generator before releasing the rotor, and converter in fixed frequency control mode.

[0068] In some examples, there are two initialization methods for the generator element in the simulation model. The first initialization method is: at the initial moment, the generator is regarded as an infinite power source for participating in the simulation calculation. After the simulation reaches a steady state, the infinite power source is converted into a generator to complete the initialization. The second initialization method is: the generator is regarded as an infinite power source for participating in the simulation calculation. After the simulation starts, it is converted into a generator and exits the speed regulator in the power grid simulation model. The active power of the generator is controlled by directly inputting the mechanical torque of the generator. After the active power of the generator reaches the set target value, the speed regulator is re-engaged to automatically adjust the active power of the generator.

[0069] When the generator is initialized according to the first initialization method, the generator can be regarded as a fixed frequency control device during the initialization stage. When the generator is initialized according to the second initialization method, the generator can be regarded as a fixed active power control device during the initialization stage.

[0070] In some examples, when the device elements in the simulation model are grouped for the first time, all the generator elements are regarded as fixed active power control devices, that is, initialized according to the second initialization method mentioned above. When the number of fixed frequency control devices is insufficient, the number of generator elements initialized according to the first initialization method mentioned above is increased.

[0071] Step S13: Initialize each device element according to the power parameters of the first device group and the second device group and update the electromagnetic transient simulation model.

[0072] In some examples, step S13 includes the following steps:

[0073] Step S131: Calculate the total power of the first device group in the initialization phase and the total power limit of the second device group.

[0074] Step S132. Compare the total power in the initialization stage of the first device group with the total power limit of the second device group. If the total power in the initialization stage of the first device group is greater than the total power limit of the second device group, increase the number of device elements in the second device and update the electromagnetic transient simulation model until the total power in the initialization stage of the first device group is less than the total power limit of the second device group.

[0075] Step S133. Initialize each device element in the updated electromagnetic transient simulation model.

[0076] Specifically, denote the sum of the powers of all active power control devices in the initialization stage, that is, the total power in the initialization stage of the first device group, as P ptol (t), and denote the sum of the power limits of all frequency control devices at all times in the initialization stage, that is, the total power limit of the second device group, as P flim (t), calculate ΔP(t) = P ptol (t) - P flim (t). When ΔP(t) > 0, increase the number of frequency control devices and update the electromagnetic transient simulation model until ΔP(t) < 0.

[0077] P ptol (t) can be regarded as the unbalanced power generated by the active power control devices during the initialization of the electromagnetic transient simulation model, and the function of the frequency control devices is to absorb the unbalanced power during the startup process. If ΔP(t) > 0, it means that the unbalanced power exceeds the output power limit of the frequency control devices, and the unbalanced power is too large, which may generate unreasonable power flows. For example: in the receiving-end power grid model containing a DC converter station, during the DC startup process, if 1 generator is set to the frequency control mode, during the DC power increase process, the unbalanced power in the system is only borne by 1 unit, and the generator output may be very large, and the power flow is unreasonable. At this time, ΔP(t) > 0 appears, and the grouping needs to be optimized, and the number of generators in the frequency control mode needs to be increased to disperse the unbalanced power until ΔP(t) < 0 is satisfied.

[0078] In some examples, since the generator has the function of switching between the constant power control mode and the frequency control mode, when adjusting the number of frequency control devices, priority is given to increasing the number of generators in the frequency control mode.

[0079] In some examples, the calculation process of the power parameters of the active power control devices is as follows:

[0080] Set the power ramp rate and power target value of each device element in the first device group;

[0081] Calculate the total power in the initialization stage of the first device group according to the power ramp rate and power target value of each device element.

[0082] Step S14. Conduct electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

[0083] In some examples, the initialization in step S13 further includes the following steps:

[0084] Set the initial phase angles of the device components in the second device group to be the same.

[0085] Specifically, in the initial state, set the same power angle for all constant-frequency control devices, usually set to be the same as the bus angle of the constant-frequency control converter. If there is no constant-frequency control converter, set it to 0°.

[0086] In some instances, the initialization in step S13 further includes the following steps:

[0087] Let the device components in the first device group increase their power at the set power ramp rate until the power target value is reached;

[0088] When the active power of the generator components in the second device group reaches the power limit after starting, release the rotors of the generator components and put the governor components into the electromagnetic transient simulation model.

[0089] Specifically, after the simulation starts, the constant active power control devices increase their power at the set rate and stop rising after reaching the set power target value. For the constant-frequency control devices, to prevent disturbances caused by the generator output exceeding the limit and then being released, if the active power of the generator reaches the generator power limit during the initialization phase, the generator immediately releases the rotor and the governor is put into operation.

[0090] Further refer to Figure 2 , Another embodiment of the present invention provides an implementation process of a power grid electromagnetic transient simulation method, including the following steps:

[0091] Step S21. Conduct power flow calculation based on the electromechanical transient simulation model of the power grid, and establish an electromagnetic transient simulation model according to the power flow calculation results.

[0092] Step S22. Divide the load components and power source device components in the electromagnetic transient simulation model into a constant active power control device group and a constant frequency control device group according to the active power control mode in the initialization phase.

[0093] Among them, all generator components are regarded as constant active power control devices during the first grouping.

[0094] Step S23. Set the power ramp rate and power target value of the constant active power control devices.

[0095] Among them, the power target value is set with reference to the power flow calculation results or other calculation requirements. To reduce the simulation time, the power ramp rate is set according to the maximum rate allowed by the device.

[0096] Step S24. Obtain the sum of the powers of all the constant active power control devices in the initialization stage, denoted as P ptol (t), and obtain the sum of the power limit values of all the constant frequency control devices at all times in the initialization stage, denoted as P flim (t).

[0097] Among them, before the generator is released, it participates in the calculation as an infinite power source, and the power limit value of this infinite power source is taken as the active power limit value of the generator.

[0098] Step S25. Calculate ΔP(t) = P ptol (t) - P flim (t). When ΔP(t) > 0, increase the number of constant frequency control devices, update the electromagnetic transient simulation model, and repeat steps S22 - S24 until ΔP(t) < 0.

[0099] Step S26. Set the initial phase angles of all the constant frequency control devices to be the same.

[0100] Step S27. Start the simulation to make the device components in the electromagnetic transient simulation model reach a steady state.

[0101] The constant active power control devices increase their powers at the set rate and stop rising after reaching the set power target value; for the constant frequency control devices, to prevent disturbances caused by the generator output exceeding the limit and then releasing, when the active power of the generator reaches the generator power limit value during the initialization startup stage, the generator immediately releases the rotor and engages the governor.

[0102] Step S28. Conduct electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

[0103] The power grid electromagnetic transient simulation method provided by the above embodiments of the present invention groups the load and power supply devices in the power grid according to the active power control mode in the initialization stage. Especially for synchronous generators, according to the state and control method in the initialization stage, they can be regarded as either constant active power control devices or constant frequency control devices, greatly improving the simulation adaptability of the power grid model with multiple types of power sources.

[0104] The following uses two examples to illustrate the power grid electromagnetic transient simulation method provided by the above embodiments.

[0105] Example 1:

[0106] Refer to Figure 3 , which shows one of the topological structures of the power grid, where the power of the photovoltaic unit is 500 MW, the power of the hydroelectric unit is 1000 MW, the power capacity of the pumped - storage unit is 300 MW, and the capacity of the converter station is 2000 MW.

[0107] Group the load and power supply equipment in the power grid according to the active power control mode in the initialization stage. The constant active power control equipment includes photovoltaic units and hydroelectric generating units, and the constant frequency control equipment includes pumped storage units and VF control converter stations.

[0108] Set the power ramp rates of the hydroelectric generating units and photovoltaic units to be P g (t) = 100t and P v (t) = 50t, and the initialization stage is 0 - 10 s.

[0109] Then, in this example, the total power of the constant active power control equipment is 150t, the power limit of the constant frequency control equipment is 2300 MW, and in the initialization stage (0 - 10 s), ΔP(t) = P ptol (t) - P flim (t) = 150t - 2300 MW. Since ΔP(t) < 0, there is no need to change the grouping in the simulation model and the number of equipment in each group.

[0110] Set the same initial phase angle for the pumped storage unit and the VF converter station. For example, if the initial phase angle of the VF converter station bus is 90°, then the initial angle of the pumped storage generator is also set to 90°.

[0111] After the simulation starts, the hydroelectric generating units and photovoltaic units increase their powers according to the set power ramp rates and reach the power target values at 10 s, that is, P g (t) = 100t and P v (t) = 50t.

[0112] During the process of the photovoltaic units and hydroelectric generating units increasing their powers, the pumped storage units and VF control converter stations of the constant frequency control equipment absorb the unbalanced power. During the power increase process, the pumped storage units and the converter stations absorb power. If the pumping power of the pumped storage unit > 300 MW, then release the rotor of the pumped storage unit and put the governor into operation. The pumped storage unit operates at a power of 300 MW, and the powers of the photovoltaic units and hydroelectric generating units are then absorbed by the converter station.

[0113] Example 2:

[0114] Refer to Figure 4 , which shows another topological structure of the power grid, where the power of the hydroelectric generating unit is 5000 MW.

[0115] Group the load and power supply equipment in the power grid according to the active power control mode in the initialization stage. The constant active power control equipment includes the sending - end constant active power converter station, and the constant frequency control equipment includes the hydroelectric generating unit, that is, all the hydroelectric generating units operate in the constant frequency control mode during the initialization stage.

[0116] Set the power target value and ramp rate of the converter station. Assume that the power ramp rate of the converter station is approximately P d (t) = 1000t, and the initialization stage is 0 - 5s.

[0117] Then, in this example, the total power of the constant active power control equipment is 1000t, and the power limit of the constant frequency control equipment is 5000MW. During the initialization stage (0 - 5s), ΔP(t) = P ptol (t) - P flim (t) = 1000t - 5000MW. Since ΔP(t) < 0, there is no need to change the grouping and the number of equipment in each group in the simulation model.

[0118] Set the initial angle of the hydro - generator set to 0°.

[0119] After the simulation starts, the DC constant active power converter station increases its power at the set rate, that is, P d (t) = 1000t, and reaches the power target value at 5s.

[0120] During the process of the DC constant active power converter station increasing its power, the constant frequency controlled hydro - generator sets absorb its unbalanced power. During the power - rising process of the DC constant active power converter station, if the output of a certain hydro - generator set exceeds the rated power, then the rotor of this hydro - generator set is released and the governor is put into operation to maintain the rated power operation. The remaining hydro - generator sets continue to operate in the constant frequency control mode.

[0121] In the above - disclosed embodiments, a power grid electromagnetic transient simulation method is described in detail. The disclosed method can be implemented by various forms of equipment. Therefore, the present invention also discloses a power grid electromagnetic transient simulation device corresponding to the above - mentioned method. Specific embodiments are given below for detailed description.

[0122] As Figure 5 shown, an embodiment of the present invention provides a power grid electromagnetic transient simulation device 500, including:

[0123] A model acquisition unit 510, configured to acquire the electromagnetic transient simulation model of the power grid.

[0124] A grouping unit 520, configured to divide the equipment components in the electromagnetic transient simulation model into a first equipment group and a second equipment group according to the active power control mode during the simulation initialization stage.

[0125] An initialization unit 530, configured to initialize each equipment component according to the power parameters of the first equipment group and the second equipment group and update the electromagnetic transient simulation model.

[0126] A simulation execution unit 540, configured to perform electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

[0127] In some examples, the initialization unit 530 performs the following initialization steps:

[0128] Calculate the total power in the initialization phase of the first device group and the total power limit of the second device group.

[0129] Compare the total power in the initialization phase of the first device group with the total power limit of the second device group. If the total power in the initialization phase of the first device group is greater than the total power limit of the second device group, increase the number of device elements in the second device and update the electromagnetic transient simulation model until the total power in the initialization phase of the first device group is less than the total power limit of the second device group.

[0130] Initialize each device element in the updated electromagnetic transient simulation model.

[0131] Specifically, group the load and power supply devices in the power grid according to the active power control mode in the initialization phase, into a constant active power control device group and a constant frequency control device group. The output directions of the devices in the constant frequency control group must be the same, that is, they can only all generate active power or all absorb active power.

[0132] In some examples, the initialization unit 530 also performs the following initialization steps:

[0133] Set the initial phase angles of the device elements in the second device group to be the same.

[0134] In some examples, the initialization unit 530 also performs the following initialization steps:

[0135] Let each device element of the first device group increase its power at the set power ramp rate until it reaches the power target value;

[0136] When the active power of the generator element in the second device group reaches the power limit after startup, release the rotor of the generator element and put the governor element into the electromagnetic transient simulation model.

[0137] For the power grid electromagnetic transient simulation device 500 provided by the embodiments of the present application, its implementation principle and the technical effects produced are the same as those of the foregoing method embodiments. For the sake of brief description, for the parts not mentioned in the device embodiments, reference may be made to the corresponding content in the foregoing method embodiments.

[0138] Refer to Figure 6 , which shows a hardware structure block diagram of an electronic device, including: at least one processor 1, at least one communication interface 2, at least one memory 3, and at least one communication bus 4;

[0139] In the embodiments of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 complete mutual communication through the communication bus 4;

[0140] The processor 1 may be a central processing unit (CPU), or a specific application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention, etc.;

[0141] The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory;

[0142] Among them, the memory stores a program, and the processor can call the program stored in the memory. The program is used to implement each processing flow of the aforementioned power grid electromagnetic transient simulation method.

[0143] The embodiments of the present invention also provide a readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the power grid electromagnetic transient simulation method provided by any possible implementation manner of the above embodiments and / or combined embodiments.

[0144] It should be understood that although each step in the drawings is shown in sequence according to the indication of the arrow, these steps do not necessarily have to be executed in the order indicated by the arrow. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in each drawing may include multiple sub-steps or multiple stages. These sub-steps or stages do not necessarily have to be executed at the same moment, but can be executed at different moments. The execution order of these sub-steps or stages does not necessarily have to be sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0145] Those skilled in the art can understand that the structures shown in the drawings are only block diagrams of some structures related to the solution of the present application, and do not constitute a limitation on the terminal device to which the solution of the present application is applied. The specific terminal device may include more or fewer components than those shown in the drawings, or combine some components, or have different component arrangements.

[0146] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0147] Finally, it should also be noted that in this article, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0148] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power grid electromagnetic transient simulation method, characterized in that, including: Obtain the electromagnetic transient simulation model of the power grid; Divide the equipment components in the electromagnetic transient simulation model into a first equipment group and a second equipment group according to the active power control mode in the simulation initialization stage; Initialize each equipment component according to the power parameters of the first equipment group and the second equipment group and update the electromagnetic transient simulation model; Perform electromagnetic transient simulation based on the updated electromagnetic transient simulation model; Among them, initializing each equipment component according to the power parameters of the first equipment group and the second equipment group includes: Calculate the total power in the initialization stage of the first equipment group and the total power limit of the second equipment group; Compare the total power in the initialization stage of the first equipment group with the total power limit of the second equipment group. If the total power in the initialization stage of the first equipment group is greater than the total power limit of the second equipment group, increase the number of equipment components in the second equipment group and update the electromagnetic transient simulation model until the total power in the initialization stage of the first equipment group is less than the total power limit of the second equipment group; Initialize each equipment component in the updated electromagnetic transient simulation model; The equipment components in the first equipment group include equipment that directly controls the active power according to the set active power target value in the initialization stage, and the equipment components in the second equipment group include equipment that takes maintaining the power grid frequency constant as the control target in the initialization stage.

2. The power grid electromagnetic transient simulation method according to claim 1, characterized in that, The increasing the number of equipment components in the second equipment group includes: Increase the number of generator components that take maintaining the power grid frequency constant as the control target in the initialization stage.

3. The power grid electromagnetic transient simulation method according to claim 1, characterized in that, The steps of the initialization include: Set the initial phase angles of the equipment components in the second equipment group to be the same.

4. The power grid electromagnetic transient simulation method according to claim 1, characterized in that, The steps of the initialization further include: Make each equipment component in the first equipment group increase the power according to the set power ramp rate until each equipment component reaches the power target value; When the active power of the generator component in the second equipment group reaches the power limit after starting, release the rotor of the generator component and put the speed governor component into the electromagnetic transient simulation model.

5. The power grid electromagnetic transient simulation method according to claim 1, characterized in that, The method further includes: Obtain the electromechanical transient simulation model of the power grid; Perform power flow calculation on the power grid according to the electromechanical transient simulation model; Establish an electromagnetic transient simulation model according to the calculation results of the power flow calculation.

6. A power grid electromagnetic transient simulation device, characterized in that, including: A model acquisition unit configured to obtain the electromagnetic transient simulation model of the power grid; A grouping unit configured to divide the equipment components in the electromagnetic transient simulation model into a first equipment group and a second equipment group according to the active power control mode in the simulation initialization stage; An initialization unit configured to initialize each equipment component according to the power parameters of the first equipment group and the second equipment group and update the electromagnetic transient simulation model; When the initialization unit executes the initialization of each equipment component according to the power parameters of the first equipment group and the second equipment group, it specifically executes the following process: Calculate the total power in the initialization stage of the first equipment group and the total power limit of the second equipment group; Compare the total power in the initialization stage of the first device group with the total power limit of the second device group. If the total power in the initialization stage of the first device group is greater than the total power limit of the second device group, increase the number of device elements in the second device group and update the electromagnetic transient simulation model until the total power in the initialization stage of the first device group is less than the total power limit of the second device group; Initialize each device element in the updated electromagnetic transient simulation model; the device elements of the first device group include devices that directly control the active power according to the set active power target value in the initialization stage, and the device elements of the second device group include devices that take maintaining the grid frequency constant as the control target in the initialization stage; A simulation execution unit, configured to perform electromagnetic transient simulation based on the updated electromagnetic transient simulation model.

7. A power grid electromagnetic transient simulation system, characterized in that, Comprising a memory and a processor; The memory is used for storing programs; The processor is used for calling the program stored in the memory to execute the grid electromagnetic transient simulation method according to any one of claims 1 to 5.

8. A readable storage medium, characterized in that, Stored thereon is a computer program which, when executed by a processor, implements the grid electromagnetic transient simulation method according to any one of claims 1 to 5.

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