Fault ride-through control correction method for aggregation equivalent modeling of new energy pooling stations of different types and models

Abstract

The invention discloses a fault ride-through control correction method for aggregation equivalent modeling of new energy pooling stations of different types and models, and belongs to the technical field of new energy pooling station modeling. The fault ride-through control correction method aims at solving the problem that a fault ride-through control correction method for new energy station equivalent models of different types and different models is lacked at present. In the correction process of the active power and the reactive power during the fault period, the complex power during the fault period is obtained by using the port voltage and the port current of the field station in the new energy pooling station during the fault period, and the complex power is decomposed into the active power and the reactive power; determining terminal voltage of the equivalent machine during the fault period by combining the equivalent machine current, obtaining active and reactive current of the equivalent machine during the fault period, and further determining active and reactive current control parameters of the corrected equivalent model during the fault period; and respectively correcting the active power of the active current in the fault period, the power in the fault period and the initial active current to obtain the overall active power, and correcting the recovery rate based on the active power.

Description

Technical Field

[0001] This invention belongs to the field of new energy aggregation station modeling technology, and relates to a fault ride-through control correction method for new energy aggregation station aggregation equivalent modeling. Background Technology

[0002] Because renewable energy collection stations contain numerous wind farms and photovoltaic power stations of different types and models, assuming that each station is individually modeled and each transformer is modeled, along with the complex internal collection network constructed according to actual connections, would significantly increase the scale and complexity of the simulation calculations. This would severely impact the effectiveness and real-time performance of the simulation analysis, potentially leading to the "curse of dimensionality." Therefore, it is necessary to establish equivalent models for renewable energy collection stations that ensure model accuracy while improving simulation efficiency. Existing equivalent modeling methods for renewable energy stations are mainly divided into two categories: multi-unit equivalent methods and single-unit equivalent methods. Single-unit equivalent methods do not require grouping the renewable energy cluster. While these methods have low computational cost, they ignore the differences in operating states between units, often resulting in lower equivalent accuracy. Multi-unit equivalent methods can improve the model's equivalent accuracy, but existing methods require separate equivalent modeling of different types and models of renewable energy stations, followed by grouping based on different operating states. This leads to an excessive number of equivalent units, complex calculations, and difficulty in achieving good general applicability in engineering practice. To accurately characterize the external properties of renewable energy power stations using equivalent units, precise calculations of the electrical and mechanical parameters of the equivalent wind turbine generators are necessary. Currently, equivalent parameter calculations generally employ a capacity-weighted method to calculate transformer parameters. However, this method introduces significant errors in large-scale renewable energy aggregation stations due to the presence of multiple transformer stages and lacks consideration for transformer turns ratios. Therefore, a method for aggregated equivalent modeling of renewable energy aggregation stations with different types and models is needed to achieve efficient analytical equivalent modeling. However, aggregated equivalent modeling for renewable energy aggregation stations with different types and models also has its own limitations. Specifically, it can lead to changes in the control process due to variations in the aggregated equivalent model, requiring correction. Current correction methods are not suitable for such situations. Summary of the Invention

[0003] To address the current issue that the equivalent modeling of new energy collection stations does not consider the different types and models of new energy power stations, there is a lack of a fault ride-through control correction method for equivalent models of new energy power stations with different types and models.

[0004] A fault ride-through control correction method based on aggregated equivalent modeling of new energy collection stations of different types and models, including the correction process of active power and reactive power during the fault, and / or the correction process of active power at the fault recovery starting point.

[0005] Correction of active and reactive power during a fault includes:

[0006] Measure the port voltage of the i-th station in the new energy collection station during the fault period. and port current Thus, the complex power of the i-th power station during the fault period is obtained. Then, the complex power of the equivalent machine during the fault period is obtained by summing the complex power of the n new energy power stations. And decomposed into active power and reactive power ;

[0007] Through the voltage at the fault point Determine the terminal voltage of the conversion machine during the fault period by comparing the conversion machine current with the conversion machine current. and combined with active power and reactive power Obtain the active current of the shift machine during the fault period. and reactive current This allows for the determination of active current control parameters during faults in the equivalent model. and reactive current control parameters That is, the control parameters of the active and reactive currents in the corrected equivalent model, so as to realize the correction of active and reactive power during the fault period;

[0008] Correction of active power at the fault recovery starting point includes:

[0009] For substations where the active current control method at the recovery starting point is based on the active current during the fault period, the recovery starting voltage at the fault point is used. The terminal voltage of the equivalent machine at the fault recovery starting point is determined by the equivalent machine current. Active current during the fault The active current at the fault recovery starting point is obtained by multiplying the terminal voltage at the fault recovery starting point by the active current during the fault period. The control method is based on the active power at the fault recovery starting point of the station. For power stations where the active current control method at the recovery starting point is based on the power during the fault period, the active power during the fault period of the i-th power station of this type will be used. Summing up yields the active power at the fault recovery starting point of this type of power station. For power stations where the active current control method at the recovery point is based on a percentage of the initial active current, the initial active current of this type of power station in the renewable energy collection station is obtained by collecting data. This allows us to determine the active current at the starting point of the fault recovery for the i-th substation of this type. The active current at the fault recovery starting point of each station is summed to obtain the result. The active power at the fault recovery starting point is obtained by multiplying it by the terminal voltage at the fault recovery starting point of the equal-mode machine. The active power at the fault recovery starting point of each type of station is summed to obtain the active power at the fault recovery starting point of the equivalent machine. .

[0010] Furthermore, through the voltage at the fault point Determine the terminal voltage of the conversion machine during the fault period by comparing the conversion machine current with the conversion machine current. The process includes:

[0011] The measured port currents of each station are summed to obtain the equivalent machine terminal current during the fault. ,according to Equivalent impedance of the first-stage transformer The voltage drop at point T1 of the first stage transformer in the equivalent model is obtained. According to the turns ratio of the first-stage transformer Determine the current on the J side of the first-stage transformer. ;

[0012] according to Equivalent impedance of the second-stage transformer The voltage drop at point T2 of the second-stage transformer is obtained. Therefore, based on the turns ratio of the second-stage transformer Determine the J-side current of the second-stage transformer. ;

[0013] according to and the equivalent impedance of the current flowing through the second-stage transformer and the collector network The voltage drop at the collector network is obtained. ;

[0014] Compare each voltage drop with the voltage at the fault point Adding them together gives the terminal voltage of the equivalent machine during the fault period. .

[0015] Furthermore, the voltage drop at the first-stage transformer T1 The current on the J side of the first-stage transformer .

[0016] Furthermore, the voltage drop at the second-stage transformer T2 The J-side current of the second-stage transformer .

[0017] Furthermore, the voltage drop at the collector network .

[0018] Furthermore, the active current of the shift machine during the fault. and reactive current .

[0019] Furthermore, the active current control parameters during the fault period in the equivalent model The reactive current control parameters are as follows:

[0020] ,

[0021] In the formula, This refers to the total rated capacity of the new energy power stations; To reach the low voltage ride-through threshold.

[0022] Furthermore, the terminal voltage of the equivalent machine is determined during the correction process of the active power at the fault recovery starting point. The method and the terminal voltage of the equivalent machine during the fault The method is the same.

[0023] Furthermore, the active current at the fault recovery starting point of the i-th substation type, based on the percentage of initial active current. as follows:

[0024] ,

[0025] ,

[0026] ,

[0027] Where n3 is the number of stations whose active current control method at the point of recovery is based on a percentage of the initial active current; The active current at the recovery point is calculated using a factor of 1; The active current at the recovery point is calculated using a factor of 2.

[0028] Furthermore, the correction method also includes a continuous correction process for the recovery rate of the equivalent model during the fault recovery phase, specifically including:

[0029] The recovery rate of the equivalent model during the fault recovery phase is continuously corrected to the recovery rate of the new energy collection station, and the active power of the equivalent model is used as the basis for this correction. express:

[0030]

[0031] In the formula, Let be the recovery rate of the i-th station; This is the time to clear the fault; Let be the active power at the moment the fault is cleared at the i-th substation; This marks the moment when station 1 returns to a steady state. This is the moment when the i-th station reaches steady state; Let be the active power of the i-th power station under normal operating conditions;

[0032] Active power in equivalent models exist Time period according to rate Restore; in Time period according to rate Restore; in Time period according to rate Restore; and so on, until... At all times according to the rate Return to steady-state output.

[0033] Beneficial effects:

[0034] This invention provides a fault ride-through control correction method for equivalent models of renewable energy power stations of different types and models, enabling the corrected equivalent models to perform better during fault ride-through. Examples verify the adaptability of the equivalent models for renewable energy power stations in two output scenarios: high power range (active power P range of 0.7pu≤P≤0.9pu) and low power range (active power P range of 0.2pu≤P≤0.4pu). It can be seen that, under different output scenarios, the equivalent accuracy of the corrected equivalent models is improved compared to traditional single-unit equivalent models. This demonstrates that this invention not only enables the corrected equivalent models to perform better during fault ride-through but also has good adaptability to the output scenarios of renewable energy power stations. Attached Figure Description

[0035] Figure 1 Topology diagram of the new energy aggregation station;

[0036] Figure 2 This is an equivalent diagram during the fault period;

[0037] Figure 3 A schematic diagram of the fault recovery starting point;

[0038] Figure 4 Detailed model of a new energy collection station;

[0039] Figure 5 The results are from simulations of high-power scenarios.

[0040] Figure 6 The results are from a low-power scenario simulation. Detailed Implementation

[0041] To address the current issues of neglecting to consider different types and models of new energy power stations in equivalent modeling and the lack of control correction methods applicable to the entire fault ride-through process in equivalent simulation models, this invention proposes a fault ride-through control correction method suitable for aggregated equivalent modeling of new energy power stations with different types and models. A case study of a new energy power station in western Jilin Province verifies the method's effectiveness, showing that the equivalent model of the new energy power station can well represent the response of the detailed model under different scenarios. Before further explanation, it should be noted that this invention is not limited to the equivalent modeling method defined in the embodiments, but can also be applied to other equivalent modeling methods. Any equivalent model that equates the generator transformers of each power station to the first-stage transformer T1 and the power station transformers to the second-stage transformer T2 can be used, i.e., it can determine the equivalent transformer ratio of the first-stage transformer. Equivalent turns ratio of the second-stage transformer This invention is applicable to all aggregate equivalence models. The invention will be further described below with reference to specific embodiments.

[0042] This embodiment presents a fault ride-through control correction method for aggregated equivalent modeling of new energy collection stations of different types and models. It corrects the fault ride-through control of these stations based on the aggregated equivalent modeling process. The method includes the following steps:

[0043] Step 1: To intuitively explain the calculation process, this implementation method takes a doubly fed wind power cluster as an example. During the fault period, the new energy power station adopts low voltage ride-through control. Since the models, types and control parameters of the power stations under the new energy collection station are different, directly using a certain control parameter for equivalent modeling will produce a large error. Therefore, it is necessary to correct the active current and reactive current control parameters of the equivalent model during the fault period.

[0044] First, measure the port voltage of the i-th station in the new energy collection station during the fault period. and port current The complex power of the i-th power station during the fault can be calculated using the following formula. :

[0045]

[0046] The complex power of the equivalent generator during a fault is obtained by summing the complex power of n doubly-fed wind farms. And decomposed into active power and reactive power :

[0047]

[0048]

[0049] Where n represents the total number of all new energy power stations.

[0050] Due to the fault, the terminal voltage of the shift machine was low. It cannot be measured directly, so it is necessary to check the voltage at the fault point. The current at the equivalent unit is then used for calculation. The measured currents at each station port are summed to obtain the equivalent unit terminal current during the fault period. The voltage drop at point T1 of the first-stage transformer in the equivalent model can be calculated using the following formula. :

[0051]

[0052] In the formula, This is the equivalent impedance of the first-stage transformer.

[0053] Since the current passes through two transformers with a turns ratio that is not 1, the calculation process needs to be adjusted according to the turns ratio of the two transformers, based on the turns ratio of the first transformer. Calculations show that the current on the J side of the first-stage transformer is... :

[0054]

[0055] The voltage drop at T2 of the second-stage transformer can be obtained by further calculation using the above method. With the J-side current of the second-stage transformer :

[0056]

[0057]

[0058] In the formula, This is the equivalent impedance of the second-stage transformer; This refers to the turns ratio of the second-stage transformer.

[0059] The current flowing through the second-stage transformer is compared with the equivalent impedance of the collector network. Multiplying them together gives the voltage drop at the collector network. :

[0060]

[0061] Compare each voltage drop with the voltage at the fault point Adding them together gives the terminal voltage of the equivalent machine during the fault period. The active current of the equivalent unit during the fault can be obtained through calculation. and reactive current :

[0062]

[0063]

[0064] After calculating the active and reactive currents of the equivalent model, the active current control parameters during the fault period of the equivalent model are determined. and reactive current control parameters Perform the calculation:

[0065]

[0066] In the formula, This represents the total rated capacity of the doubly fed wind power cluster. To reach the low voltage ride-through threshold, it is set to 0.9 pu according to the national standard.

[0067] This allows us to calculate the control parameters of the active and reactive currents of the corrected and improved single-machine equivalent model, thus realizing the correction process of active and reactive power during faults.

[0068] Step Two: Due to the large number and different models of the new energy collection stations, the fault recovery starting point of each station is not consistent, and the active current control method at the recovery starting point is also different for each station. Therefore, it is necessary to correct the fault recovery starting point of the equivalent machine. The active current control parameters for the recovery starting point and recovery process of new energy stations generally use slope recovery, while reactive current generally does not use a special control method. Therefore, the reactive current control parameters do not need to be corrected; only the control parameters for the active current part need to be corrected. Similar to the equivalent method during a fault, based on the principle of equal power before and after the equivalent, the active power at the fault recovery starting point of the traditional single-machine equivalent model is corrected. (See attached...) Figure 3 The diagram shown is an aggregated isobaric diagram of the fault recovery starting point.

[0069] There are three active current control methods for the crossing recovery starting point of each station in this new energy aggregation station. The active power of each station needs to be calculated and summed separately. Specifically, the active current control method based on the number of stations with active current during the fault period is n1; the control method based on the number of stations with power during the fault period is n2; and the control method based on the number of stations with a percentage of the initial active current is n3.

[0070]

[0071] First, the active current control method for the crossing recovery starting point is calculated based on the active current during the fault period. According to the above-mentioned fault period correction method, the active current during the fault period of the i-th station of this type can be determined. The active current summed from all stations The active power of this type of power station can be obtained by multiplying it by the terminal voltage at the fault recovery starting point of the equivalent unit.

[0072] Due to the terminal voltage of the isolator at the fault recovery starting point It cannot be measured directly, so it is necessary to restore the starting voltage at the fault point. The calculation method for the equivalent machine current is the same as that for the equivalent machine terminal voltage during the aforementioned fault period, as shown in the following formula:

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] In the formula, Let be the generator terminal current at the recovery starting point after the i-th station fault; This is the equivalent machine terminal current; This refers to the voltage drop at T1 of the first-stage transformer; This refers to the J-side current of the first-stage transformer; This refers to the voltage drop at point T2 of the second-stage transformer. This refers to the J-side current of the second-stage transformer; This is the voltage drop at the collector network.

[0081] The summed active current during the fault period Multiplying this by the terminal voltage at the fault recovery starting point of the station yields the active power at the fault recovery starting point, where the active current control method is based on the active current during the fault. :

[0082]

[0083]

[0084] Where n1 is the number of stations whose active current control mode at the point of recovery is based on the active current during the fault period;

[0085] Secondly, the active current control method for calculating the recovery starting point is based on the active power of the station during the fault period. According to the above-mentioned fault period correction method, the active power of the i-th station of this type during the fault period can be obtained. This allows for the calculation of the active power at the fault recovery starting point of this type of power station. :

[0086]

[0087] Where n2 is the number of stations whose active current control mode at the point of recovery is based on the power during the fault period;

[0088] Finally, the active current control method for restoring the starting point is calculated based on the active power of the power station as a percentage of the initial active current. The initial active current of this type of power station in the renewable energy collection station is obtained by collecting data. The active current at the fault recovery starting point of the i-th substation of this type is calculated according to the following formula. The active current at the fault recovery starting point of each station is summed to obtain the result. Multiplying this value by the equivalent terminal voltage at the fault recovery starting point obtained from the above calculation yields the active power at the fault recovery starting point for this type of power station. :

[0089]

[0090]

[0091]

[0092] Where n3 is the number of stations whose active current control method at the point of recovery is based on a percentage of the initial active current; The active current at the recovery point is calculated using a factor of 1; The active current at the recovery point is calculated using a factor of 2.

[0093] By summing the active power at the fault recovery starting point of each type of station, the active power at the fault recovery starting point of the equivalent unit can be obtained. Calculations show that the active current at the fault recovery starting point of the equivalent machine is... :

[0094]

[0095]

[0096] The active current control method for the recovery starting point of the equivalent model is selected as a percentage of the initial active current. After calculating the active current of the equivalent model, the active current control parameters for the fault recovery starting point of the equivalent model are calculated:

[0097]

[0098]

[0099] In the formula, The active current calculation coefficient for restoring the starting point in the equivalent model is 1; The active current calculation coefficient is 2 for restoring the starting point of the equivalent model.

[0100] This allows us to calculate the corrected active current control parameters of the single-unit equivalent model, thus realizing the correction process of the active power at the fault recovery starting point.

[0101] Step 3: Since the new energy collection station contains different models and types of stations, their recovery slopes are not the same. Therefore, the post-fault recovery process is a superposition of responses from each station. Direct equivalence will produce a large error. Therefore, it is necessary to continuously correct the recovery rate of the equivalent model in the fault recovery stage to the recovery rate of the new energy collection station to eliminate equivalence errors. The calculation process is shown in the following formula:

[0102]

[0103] In the formula, Let be the recovery rate of the i-th station; This is the time to clear the fault; Let be the active power at the moment the fault is cleared at the i-th substation; This marks the moment when station 1 returns to a steady state. This is the moment when the i-th station reaches steady state; Let be the active power of the i-th power station under normal operating conditions.

[0104] From the above equation, we can see that the active power of the corrected improved single-machine equivalent model is... exist Time period according to rate Restore; in Time period according to rate Restore; in Time period according to rate Restore; and so on, until... At all times according to the rate Return to steady-state output.

[0105] Example

[0106] This embodiment uses the following example to illustrate an aggregated equivalent modeling method for a multi-level transformer new energy collection station containing different types and models of transformers. For example... Figure 1 The renewable energy collection stations shown, which include different types and models, are first modeled using equivalent methods. The specific process is as follows:

[0107] Step 1: To intuitively explain the calculation process, this implementation method uses a doubly-fed induction generator (DFIG) wind power cluster as an example. (See attached...) Figure 2 The diagram shown is an improved single-machine equivalent model. First, the parameters of the equivalent machine are calculated.

[0108]

[0109] In the formula, n represents the total number of stations in the new energy collection station; Rated capacity (MVA) for a single site; Rated power (MW) for a single power station. This is the rated capacity of the equalization machine. This is the rated power of the isobaric machine.

[0110] It should be noted that this implementation method uses a doubly fed wind power cluster as an example for equivalent modeling, but the equivalent modeling method is actually the same for other new energy types.

[0111] Step Two: Because the new energy collection station spans multiple transformers, calculating the equivalent parameters of the transformers using the capacity-weighted method will produce significant errors. To mitigate the impact of these errors, this invention uses the loss equality method to calculate the equivalent impedance of the transformer, as shown in the attached diagram. Figure 2 As shown, the generator terminal transformers of each station are equivalent to the first-stage transformer T1, and the station transformers are equivalent to the second-stage transformer T2. The specific calculation method for the current and equivalent impedance on the I side of the first-stage transformer is shown in the following formula:

[0112]

[0113]

[0114] In the formula, Let be the apparent power on the I-th terminal transformer; Let be the voltage on side I of the i-th terminal transformer; Let I be the current on the I-th terminal transformer. This is the current on the I side of the equivalent primary transformer; Let be the impedance of the i-th terminal transformer; This is the equivalent impedance of the first-stage transformer.

[0115] The calculation methods for the current and equivalent impedance on side I of the second-stage transformer are the same as those for the first stage. The specific calculation formulas are as follows:

[0116]

[0117]

[0118] In the formula, Let be the apparent power on the I-side of the transformer at the i-th substation; Let be the voltage on side I of the transformer at the i-th substation; Let I be the current on the I-th transformer of the i-th substation; This is the sum of the currents on side I of the equivalent secondary transformer; Let be the impedance of the i-th substation transformer; This is the equivalent impedance of the second-stage transformer.

[0119] In addition, the transformer's turns ratio also affects the accuracy of the equivalent model. Therefore, based on the relationship between the turns ratio and the current, the calculation method for the transformer's equivalent turns ratio is as follows:

[0120]

[0121] In the formula, The equivalent current on the high-voltage side of the second-stage transformer is calculated using the following formula; This refers to the equivalent turns ratio of the first-stage transformer. This is the equivalent turns ratio of the second-stage transformer.

[0122] Step 3: The main calculation content of the equivalent parameters of the collector network is the equivalent impedance of the equivalent line. Following the principle that the power and current injected into the nodes are equal before and after equivalence, as shown in the attached diagram... Figure 2 The calculations shown indicate that the equivalent current on the high-voltage side of the second-stage transformer is:

[0123]

[0124] In the formula, Let be the apparent power of the power collection network of the i-th power station in the new energy collection station; Let be the port voltage of the i-th station in the new energy collection station; Let be the current in the current collector network of the i-th power station in the new energy collection station.

[0125] The equivalent voltage of the high-voltage side busbar of the second-stage transformer is:

[0126]

[0127] The equivalent impedance of the collector network is:

[0128]

[0129] In the formula, The voltage at the grid connection point of the new energy collection station.

[0130] At this point, the calculation of key parameters for the improved single-unit equivalent model is complete, realizing the calculation of aggregated equivalent parameters for new energy collection stations spanning multiple transformer levels.

[0131] Adopting attachment Figure 4 Taking the new energy collection station shown as an example for verification, an aggregated equivalent model was established in PSASP software, and the equivalent model parameters were calculated according to the improved aggregated equivalent method described above. Then, the control correction method of the specific implementation method was used for control.

[0132] The adaptability of the equivalent model for the new energy collection station under two output scenarios—high power range (active power P range of 0.7pu≤P≤0.9pu) and low power range (active power P range of 0.2pu≤P≤0.4pu)—was verified. In the established detailed model, improved single-unit equivalent model, and traditional single-unit equivalent model of the new energy collection station, a three-phase short-circuit ground fault was simulated on the 220kV bus side of the Xiaji Xiangyang station. The fault occurred in 1 second and ended in 1.1 seconds, with a simulation time of 5 seconds. The voltage drop at the grid connection point was uniformly set to 40%. The low-voltage fault ride-through response characteristic curves of the new energy collection station under different output scenarios were tested. The output response characteristic curves of voltage, current, active power, and reactive power at the grid connection point throughout the fault process are attached. Figure 5 and attached Figure 6 As shown in the figure, the improved single-machine equivalent model achieves higher accuracy under different output scenarios compared to the traditional single-machine equivalent model, demonstrating that this method has good adaptability to the output scenarios of new energy collection stations.

[0133] It should be noted that the specific embodiments are merely explanations and illustrations of the technical solution of the present invention and should not be used to limit the scope of protection. Any modifications made in accordance with the claims and specification of the present invention that are only partial should still fall within the protection scope of the present invention.

Claims

1. A fault ride-through control correction method based on aggregated equivalent modeling of new energy collection stations of different types and models, characterized in that, This includes the correction process for active and reactive power during a fault, and / or the correction process for active power at the fault recovery start point. Correction of active and reactive power during a fault includes: Measure the port voltage of the i-th station in the new energy collection station during the fault period. and port current Thus, the complex power of the i-th power station during the fault period is obtained. Then, the complex power of the equivalent machine during the fault period is obtained by summing the complex power of the n new energy power stations. And decomposed into active power and reactive power ; Through the voltage at the fault point Determine the terminal voltage of the conversion machine during the fault period by comparing the conversion machine current with the conversion machine current. and combined with active power and reactive power Obtain the active current of the shift machine during the fault period. and reactive current This allows for the determination of active current control parameters during faults in the equivalent model. and reactive current control parameters That is, the control parameters of the active and reactive currents in the corrected equivalent model, so as to realize the correction of active and reactive power during the fault period; Correction of active power at the fault recovery starting point includes: For substations where the active current control method at the recovery starting point is based on the active current during the fault period, the recovery starting voltage at the fault point is used. The terminal voltage of the equivalent machine at the fault recovery starting point is determined by the equivalent machine current. Active current during the fault The active current at the fault recovery starting point is obtained by multiplying the terminal voltage at the fault recovery starting point by the active current during the fault period. The control method is based on the active power at the fault recovery starting point of the station. For power stations where the active current control method at the recovery starting point is based on the power during the fault period, the active power during the fault period of the i-th power station of this type will be used. Summing up yields the active power at the fault recovery starting point of this type of power station. For power stations where the active current control method at the recovery point is based on a percentage of the initial active current, the initial active current of this type of power station in the renewable energy collection station is obtained by collecting data. This allows us to determine the active current at the starting point of the fault recovery for the i-th substation of this type. The active current at the fault recovery starting point of each station is summed to obtain the result. The active power at the fault recovery starting point is obtained by multiplying it by the terminal voltage at the fault recovery starting point of the equal-mode machine. The active power at the fault recovery starting point of each type of station is summed to obtain the active power at the fault recovery starting point of the equivalent machine. .

2. The fault ride-through control correction method according to claim 1, which involves aggregated equivalent modeling of new energy collection stations of different types and models, is characterized in that... Through the voltage at the fault point Determine the terminal voltage of the conversion machine during the fault period by comparing the conversion machine current with the conversion machine current. The process includes: The measured port currents of each station are summed to obtain the equivalent machine terminal current during the fault. ,according to Equivalent impedance of the first-stage transformer The voltage drop at point T1 of the first stage transformer in the equivalent model is obtained. According to the turns ratio of the first-stage transformer Determine the current on the J side of the first-stage transformer. ; according to Equivalent impedance of the second-stage transformer The voltage drop at point T2 of the second-stage transformer is obtained. Therefore, based on the turns ratio of the second-stage transformer Determine the J-side current of the second-stage transformer. ; according to and the equivalent impedance of the current flowing through the second-stage transformer and the collector network The voltage drop at the collector network is obtained. ; Compare each voltage drop with the voltage at the fault point Adding them together gives the terminal voltage of the equivalent machine during the fault period. .

3. The fault ride-through control correction method for new energy collection stations of different types and models, as described in claim 2, is characterized in that... Voltage drop at the first-stage transformer T1 The current on the J side of the first-stage transformer .

4. The fault ride-through control correction method for new energy collection stations of different types and models according to claim 3, characterized in that, Voltage drop at the second-stage transformer T2 The J-side current of the second-stage transformer .

5. The fault ride-through control correction method for new energy collection stations of different types and models, as described in claim 4, is characterized in that... Voltage drop at the collector network .

6. The fault ride-through control correction method according to claim 5, which involves aggregated equivalent modeling of new energy collection stations of different types and models, is characterized in that... Active current of the shift machine during the fault and reactive current .

7. The fault ride-through control correction method according to claim 6, which includes aggregated equivalent modeling of new energy collection stations of different types and models, is characterized in that... Active current control parameters during faults in the equivalent model The reactive current control parameters are as follows: ， In the formula, This refers to the total rated capacity of the new energy power station; To reach the low voltage ride-through threshold.

8. A fault ride-through control correction method for aggregated equivalent modeling of new energy collection stations of different types and models, as described in any one of claims 2 to 7, characterized in that... Determining the terminal voltage of the equivalent unit during the active power correction process at the fault recovery starting point. The method and the terminal voltage of the equivalent machine during the fault The method is the same.

9. The fault ride-through control correction method according to claim 8, which includes aggregated equivalent modeling of new energy collection stations of different types and models, is characterized in that... Active current at the fault recovery starting point of the i-th substation type, based on the percentage of initial active current. as follows: ， ， ， Where n3 is the number of stations whose active current control method at the point of recovery is based on a percentage of the initial active current; The active current at the recovery point is calculated using a factor of 1; The active current at the recovery point is calculated using a factor of 2.

10. The fault ride-through control correction method according to claim 9, which includes aggregated equivalent modeling of new energy collection stations of different types and models, is characterized in that... The correction method also includes a continuous correction process for the recovery rate of the equivalent model during the fault recovery phase, specifically including: The recovery rate of the equivalent model during the fault recovery phase is continuously corrected to the recovery rate of the new energy collection station, and the active power of the equivalent model is used as the basis for this correction. express: In the formula, Let be the recovery rate of the i-th station; This is the time to clear the fault; Let be the active power at the moment the fault is cleared at the i-th substation; This marks the moment when station 1 returns to a steady state. This is the moment when the i-th station reaches steady state; Let be the active power of the i-th power station under normal operating conditions; Active power in equivalent models exist Time period according to rate Restore; in Time period according to rate Restore; in Time period according to rate Restore; and so on, until... At all times according to the rate Return to steady-state output.

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