A high-frequency correction control method and system considering centralized control of new energy

Abstract

The application discloses a kind of high-frequency correction control method and system considering centralized control new energy, comprising: obtaining existing automatic high-frequency machine tripping scheme, net controllable new energy unit information;With the power of each generator in existing high-frequency machine tripping scheme as value, the equivalent replacement amount of being replaced by new energy is calculated;Real-time active power of monitoring net controllable new energy unit;According to real-time active power and each round equivalent replacement amount, match the high-frequency machine tripping replacement scheme of current time;Before interval refresh time arrives, if high-frequency machine tripping control is triggered, then execute new energy unit machine tripping control according to the above control scheme.The application can save conventional synchronous unit resources, reduce the loss of power system inertia and primary frequency modulation capacity, which is beneficial to frequency stability control;Equivalent replacement principle is used instead of equivalent replacement method to calculate new energy unit replacement amount, which ensures the high-frequency correction control effect of replacement scheme, and can avoid over-control or under-control problem.

Description

Technical Field

[0001] This invention relates to a high-frequency switching control method and system, and more particularly to a high-frequency correction control method and system that considers centralized control of new energy sources. Background Technology

[0002] Automatic high-frequency generator disconnection (hereinafter referred to as high-frequency disconnection) measures in power systems fall under the category of the third line of defense for stable operation of power systems. These measures are emergency control measures taken to prevent a significant increase in system frequency after a serious fault occurs in the power grid.

[0003] When a DC blocking fault occurs in the power transmission system, a large amount of redundant power is fed back to the sending-end grid, causing the grid frequency to rise and exceed limits, threatening the safety and stability of the grid. When the system transient frequency exceeds the safety boundary of the third line of defense, the automatic high-frequency disconnection generator set is triggered to automatically disconnect some generator sets to ensure that the system transient frequency meets the requirements of the safety and stability guidelines ("Technical Regulations for Automatic High-Frequency Disconnection of Generator Sets in Power Systems" GB / T 40592—2021).

[0004] The long-distance, large-capacity transmission and consumption of new energy sources via high-voltage direct current (HVDC) is the main mode of new energy development in my country. The significant energy impact caused by HVDC disturbances and the unique characteristics of high-penetration new energy sources compared to conventional power sources make the high-frequency characteristics of the power grid increasingly complex. Therefore, existing high-frequency generator tripping schemes have several limitations: First, the controllable resource types are limited, typically only considering traditional synchronous generators such as hydropower and thermal power; second, the control precision is relatively coarse, as the power of a single synchronous generator is usually hundreds of thousands to millions of kilowatts, potentially leading to line overload after tripping; third, the control cost is high, as synchronous generators, in addition to active power, can also provide reactive power and inertia to the grid, actively supporting grid voltage or frequency stability; fourth, there is the coupling problem between frequency control and power angle stability, as the tripped synchronous generator may be a residual group in the dominant power angle swing mode, potentially detrimental to the power angle stability of that mode. These derivative problems make traditional high-frequency generator tripping schemes difficult to adapt to the third line of defense for frequency in new power systems.

[0005] With the integration of a high proportion of renewable energy sources, the types of controllable resources in the power grid are becoming increasingly diversified. Renewable energy units have low control costs, flexible distribution, and their disconnection does not adversely affect grid inertia or primary frequency regulation capabilities. Therefore, incorporating renewable energy units into the high-frequency tripping control strategy helps address the derivative problems arising from the disconnection of conventional units, ensuring the safe and stable operation of the power grid. In summary, optimizing the traditional high-frequency tripping control strategy has positive and far-reaching research significance for adapting the third line of defense of the power grid to the new frequency security and stability issues under the background of the new power system. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a high-frequency correction control method and system that considers centralized control of new energy sources. It uses the principle of equivalent replacement to calculate the replacement amount of new energy units, ensuring the high-frequency correction control effect of the replacement scheme and avoiding over-control or under-control problems caused by different transient characteristics of new energy units under the equivalent replacement scheme.

[0007] Technical solution: This invention includes: acquiring existing automatic high-frequency generator switching schemes and information on controllable new energy generating units within the grid; calculating the equivalent replacement amount of each generator in the existing high-frequency generator switching scheme by using its power as the value; monitoring the real-time active power of controllable new energy generating units within the grid; matching the high-frequency generator switching replacement scheme at the current moment based on the real-time active power and the equivalent replacement amount for each round; and if high-frequency generator switching control is triggered before the interval refresh time arrives, executing the new energy generating unit switching control according to the above control scheme.

[0008] The existing automatic high-frequency generator switching scheme includes the set of generators G contained in the r-th round of the high-frequency generator switching. r And the power of the kth machine in the rth round. Information such as r = 1, 2, ..., n round n round This represents the total number of passes in the existing high-frequency cutting machine solution. Let be the total number of generators in the r-th round.

[0009] The term "controllable new energy generating units within the grid" refers to new energy generating units in the existing power system that can be used as high-frequency switching control resources.

[0010] The method of using the power of each generator in the existing high-frequency generator switching scheme as the value is based on offline simulation, and uses the power of each generator in the existing high-frequency generator switching scheme as the value in round by round and generator by generator.

[0011] The equivalent replacement amount is calculated using the perturbation method to replace it with the equivalent replacement amount of new energy.

[0012] The calculation process for the equivalent replacement amount is as follows: replace the first generator in the first round of the existing high-frequency generator switching scheme with a new energy generator in the vicinity of that unit, and obtain the equivalent replacement amount through full-process time-domain simulation iteration. Using an equal-replacement scheme as the initial value, the first generator in the first round is replaced with a nearby renewable energy unit with equal power. For fault scenarios triggering high-frequency generator tripping, the system frequency response levels before and after the replacement are simulated and compared. If there is a difference in transient frequency amplitude, the replacement amount of the renewable energy unit is perturbed and iterated according to the sign and magnitude of the error until the high-frequency control effect before and after the replacement is the same. The total power of the renewable energy unit tripped at this point is recorded, which is the equivalent replacement amount for replacing one generator in one round. By analogy, the equivalent replacement amount for replacing k generators in r-wheels can be calculated one by one. The total equivalent replacement amount when all generators in the r-th round and the k-th generator in the preceding rounds are replaced with new energy sources.

[0013] Real-time active power of the controllable new energy generating units within the network Obtained through a new energy panoramic monitoring system.

[0014] The process of matching the high-frequency generator switching and replacement scheme based on real-time active power and the equivalent replacement amount in each round specifically involves: matching the real-time active power of controllable new energy units within the grid... Matching a suitable replacement solution S r.k This satisfies the following equation:

[0015]

[0016] Where, n ren This refers to the total number of controllable new energy generating units within the grid.

[0017] If high-frequency generator switching control is triggered before the interval refresh time is reached, the new energy generator switching control is executed according to the above control scheme. Specifically, the current replacement scheme is sent to the execution device of each generator in the existing high-frequency generator switching scheme, and when the high-frequency generator switching control is triggered, the new energy generator involved in the current replacement scheme is disconnected in turn.

[0018] A high-frequency correction control system considering centralized control of new energy sources is provided to implement a high-frequency correction control method that considers centralized control of new energy sources.

[0019] Beneficial effects: This invention has the following advantages:

[0020] (1) This invention targets the high-frequency correction control scheme, using new energy units to replace conventional synchronous units as the switching resources, which can save conventional synchronous unit resources, reduce the loss of power system inertia and primary frequency regulation capability, and is conducive to frequency stability control; at the same time, reducing the switching of synchronous units also reduces the risk of erroneous switching of the remaining units under the dominant power angle stability mode, and avoids weakening the transient power angle stability of the system.

[0021] (2) The present invention uses the principle of equivalent replacement rather than the method of equal quantity replacement to calculate the replacement amount of new energy units, which ensures the high-frequency correction control effect of the replacement scheme and can avoid over-control or under-control problems caused by the different transient characteristics of new energy units under the equal quantity replacement scheme. Attached Figure Description

[0022] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] like Figure 1 As shown, the high-frequency correction control method for centralized control of new energy sources of the present invention includes the following steps:

[0025] S1: Obtain existing automatic high-frequency generator tripping schemes and information on controllable new energy generating units within the grid. The existing automatic high-frequency generator tripping schemes include the set of generators G included in the r-th round of high-frequency generator tripping. r And the power of the kth machine in the rth round. Information such as r = 1, 2, ..., n round n round This represents the total number of passes in the existing high-frequency cutting machine solution. This represents the total number of generators in the r-th round. Controllable new energy generating units within the grid refer to existing new energy generating units in the power system that can be used as high-frequency generator switching control resources.

[0026] S2: Based on offline simulation, the equivalent replacement amount of each generator in the existing high-frequency generator switching scheme is calculated using the perturbation method, round by round and generator by generator, with the power of each generator as the value. The replacement amount of the new energy unit is calculated using the equivalent replacement principle, ensuring the high-frequency correction control effect of the replacement scheme. The first generator in the first round of the existing high-frequency generator switching scheme (in the order of the existing scheme) is replaced with a new energy unit in the vicinity of that unit, and the equivalent replacement amount is obtained through full-process time-domain simulation iteration. Using an equal-replacement scheme as the initial value, the first generator in the first round is replaced with a nearby renewable energy unit with equal power. For fault scenarios triggering high-frequency generator tripping, the system frequency response levels before and after the replacement are simulated and compared. If there is a difference in transient frequency amplitude, the replacement amount of the renewable energy unit is perturbed and iterated according to the sign and magnitude of the error until the high-frequency control effect before and after the replacement is the same. The total power of the renewable energy unit tripped at this point is recorded, which is the equivalent replacement amount for replacing one generator in one round. By analogy, the equivalent replacement amount for replacing k generators in r-wheels can be calculated one by one. The total equivalent replacement amount when all generators in the r-th round and the k-th generator in the preceding rounds are replaced with new energy sources.

[0027] S3: Monitor the real-time active power of controllable new energy generating units within the grid, including the real-time active power of controllable new energy generating units within the grid. It can be obtained through systems such as the New Energy Panoramic Monitoring System.

[0028] S4: Based on the real-time active power and the equivalent replacement amount in each round, match the high-frequency generator switching replacement scheme for the current moment, and match the new energy replacement scheme obtained in S2. Specifically, based on the real-time active power of controllable new energy units within the grid obtained in S3... Matching a suitable replacement solution Sr.k This satisfies the following equation:

[0029]

[0030] Where, n ren This refers to the total number of controllable new energy generating units within the grid.

[0031] S5: If high-frequency generator tripping control is triggered before the interval refresh time arrives, the new energy centralized control system will execute the new energy unit tripping control according to the control scheme set in S4; otherwise, S2 to S5 will be executed in a loop. After executing S4, the current replacement scheme can be sent to the execution devices of each generator in the existing high-frequency generator tripping scheme, and when the high-frequency generator tripping control is triggered, the new energy units involved in the current replacement scheme will be tripped in turn; the interval time is set to 5 minutes.

[0032] The present invention also includes a high-frequency correction control system that considers centralized control of new energy sources, for implementing the above-mentioned high-frequency correction control method that considers centralized control of new energy sources.

Claims

1. A high-frequency correction control method considering centralized control of new energy sources, characterized in that, include: S1: Obtain existing automatic high-frequency generator tripping schemes and information on controllable new energy generating units within the grid. The existing automatic high-frequency generator tripping schemes include the set of generators included in the r-th round of high-frequency generator tripping. And the power of the kth machine in the rth round. ,in, , This represents the total number of passes in the existing high-frequency cutting machine solution. , The total number of generators in the r-th round refers to the controllable new energy units within the grid, which are new energy units in the existing power system that can be used as high-frequency generator switching control resources. S2: Based on offline simulation, the equivalent replacement amount of each generator in the existing high-frequency generator switching scheme is calculated using the perturbation method, round by round and generator by generator, with the power of each generator as the value. The calculation process of the equivalent replacement amount is as follows: the first generator in the first round of the existing high-frequency generator switching scheme is replaced with a new energy unit in the vicinity of the first generator in the first round, and the equivalent replacement amount is obtained through full-process time-domain simulation iteration. : with equivalent replacement amount As an initial value, the first generator in the first round is replaced with a nearby renewable energy unit with equal power. For fault scenarios triggering high-frequency generator tripping, the system frequency response levels before and after the replacement are simulated and compared. If there is a difference in transient frequency amplitude, the replacement amount of the renewable energy unit is perturbed and iterated according to the sign and magnitude of the error until the high-frequency control effect before and after the replacement is the same. The total power of the renewable energy unit tripped at this point is recorded, which is the equivalent replacement amount for replacing one generator in one round. ; By analogy, the equivalent replacement amount for replacing k generators in r-wheels can be calculated one by one. The total equivalent replacement amount when the k-th generator in the r-th round and all the generators in the preceding rounds are replaced with new energy sources; S3: Monitor the real-time active power of controllable new energy generating units within the network; S4: Based on the real-time active power and the equivalent replacement amount of each round, match the high-frequency generator switching replacement scheme at the current moment, and match the new energy replacement scheme obtained in S2; S5: If high-frequency generator switching control is triggered before the interval refresh time is reached, the new energy unit switching control will be executed through the new energy centralized control system according to the control scheme set in S4; otherwise, S2~S5 will be executed in a loop.

2. The high-frequency correction control method for centralized control of new energy sources according to claim 1, characterized in that, Real-time active power of the controllable new energy generating units within the network Obtained through a new energy panoramic monitoring system.

3. The high-frequency correction control method for centralized control of new energy sources according to claim 2, characterized in that, The process of matching the high-frequency generator switching and replacement scheme based on real-time active power and the equivalent replacement amount in each round specifically involves: matching the real-time active power of controllable new energy units within the grid... Match a suitable replacement solution This satisfies the following equation: in, This refers to the total number of controllable new energy generating units within the grid.

4. The high-frequency correction control method for centralized control of new energy sources according to claim 3, characterized in that, After executing S4, the current replacement scheme is sent to the execution devices of each generator in the existing high-frequency generator switching scheme, and when the high-frequency generator switching control is triggered, the switching action is performed on the new energy units involved in the current replacement scheme in turn.

5. A high-frequency correction control system considering centralized control of new energy sources, characterized in that, This system is used to implement the high-frequency correction control method for centralized control of new energy sources as described in any one of claims 1 to 4.

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