Phase modifier configuration method considering short-circuit ratio requirement of new energy field station

Abstract

The invention discloses a phase modifier configuration method considering the short-circuit ratio requirement of a new energy field station, and the method comprises the following steps: analyzing the short-circuit ratio of the new energy field station, and improving the short-circuit ratio of the new energy field station after inputting a phase modifier. The initial short-circuit ratio of the new energy field station is KSCR1, if the power grid strength of the new energy field station needs to be improved, the short-circuit ratio of the new energy field station can be improved to a configured short-circuit ratio KSCR2 by inputting phase modifiers, and related parameters, affecting the short-circuit ratio of the new energy field station, of the phase modifiers comprise the number N of the phase modifiers and the rated capacity QSC of the phase modifiers. The short-circuit ratio of the new energy station can be increased to a target value by configuring related parameters of the phase modifier. The method has the following beneficial effects that the increase multiple of the short-circuit ratio of the new energy station before and after the phase modifier is input is defined, the influence of related parameters of the phase modifier on the short-circuit ratio of the new energy station can be analyzed, and a guiding effect is achieved for the configuration method of the phase modifier.

Description

Technical Field

[0001] The present invention relates to the technical field of safety and stability of power systems, and in particular to a phase regulator configuration method taking into account short-circuit ratio requirements of new energy stations. Background Art

[0002] In recent years, a large number of studies on the strength assessment of power electronic equipment grid-connected systems have been carried out at home and abroad, pointing out that the strength of the power system or the power grid is characterized by two main dimensions: frequency support strength and voltage support strength. The "voltage support strength" can be used to assess the relative strength of the voltage support capacity of the AC system. As a type of synchronous motor, the phase regulator can effectively improve the short-circuit capacity of the system, enhance the voltage support strength of the power grid, and improve the voltage support capacity of the power grid when disturbances occur. Since the phase regulator is a rotating element, it is limited by factors such as primary investment, maintenance cost, and site selection. It is necessary to consider the appropriate configuration plan of the phase regulator to ensure the safety and stability of the power grid and the scale of new energy acceptance. In recent years, in order to ensure the scale of new energy access in the AC / DC hybrid power grid, in addition to configuring centralized phase regulators at converter stations, small distributed phase regulators are also needed at the grid connection points or collection station buses of different voltage levels of new energy stations.

[0003] For a long time, the short-circuit ratio analysis method has provided an important reference for the planning and operation of power grids with its simplicity and intuitiveness. For power grids, after the access of power electronic equipment such as new energy units, the short-circuit ratio of the access point is usually used to reflect the strength of the power grid at that point.

[0004] The existing phase-shifting optimization configuration scheme is difficult to focus on the short-circuit ratio of new energy stations. For new energy stations, the short-circuit ratio is a reflection of the voltage support strength of the power grid of new energy stations. In terms of optimizing the configuration of phase-shifting, there is a lack of relevant configuration methods to provide technical support for improving the short-circuit ratio of new energy stations by investing in phase-shifting. Summary of the invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a phase modulator configuration method that takes into account the short-circuit ratio requirements of new energy stations. By analyzing how the investment of phase modulators can improve the short-circuit ratio of new energy stations, the phase modulator related parameters that affect the short-circuit ratio of new energy stations are obtained, and the key parameters are configured.

[0006] In order to solve the above technical problems, the technical solution of the present invention proposes a phase regulator configuration method considering the short-circuit ratio requirements of the new energy station, comprising the following steps:

[0007] Step 1: In the new power system with renewable energy as the main body, a mathematical model of phase regulator access to renewable energy stations is constructed. According to the short-circuit ratio analysis method of renewable energy stations, the initial short-circuit ratio K of renewable energy stations is obtained. SCR1 And the short-circuit ratio K after the phase regulator is put into operationSCR2 , defines the increase multiple of the short-circuit ratio of the new energy station before and after the phase-converter is put into use. The short-circuit ratio is used to describe the ratio of the system short-circuit capacity to the rated capacity of the new energy;

[0008] Step 2, by analyzing the increase multiple of the short-circuit ratio of the new energy station, the relevant parameters of the phase regulator that affect the short-circuit ratio of the new energy station are obtained, and the relevant parameters include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator;

[0009] Step 3: According to the initial short-circuit ratio and the configured short-circuit ratio of the new energy station, the relevant parameters of the phase regulator are configured to increase the short-circuit ratio of the new energy station to the target value.

[0010] Preferably, the initial short circuit ratio K SCR1 The formula is as follows:

[0011]

[0012] Among them, U s is the equivalent power amplitude of the new energy station system, X s To set the equivalent reactance of the transfer impedance of the new energy station network.

[0013] Preferably, the configuration short circuit ratio K SCR2 The formula is as follows:

[0014]

[0015] Among them, U s is the equivalent power amplitude of the new energy station system, X s To set the equivalent reactance of the network transfer impedance of the new energy station, X d ” is the equivalent reactance of the phase regulator, X k is the equivalent reactance of the transformer connected to the phase regulator, E0” is the internal potential of the phase regulator, S N is the rated capacity of the system, and Q is the total capacity of the configured phase-shifting units.

[0016] Preferably, the short-circuit ratio of the new energy station is increased by a multiple ΔK SCR The formula is as follows:

[0017]

[0018] Preferably, the increase multiple of the short-circuit ratio of the new energy station is analyzed by the following formula:

[0019]

[0020] It is found that the related parameters include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator. The capacity of the phase regulator is positively correlated with the increase multiple of the short-circuit ratio, and the equivalent impedance of the phase regulator is negatively correlated with the increase multiple of the short-circuit ratio.

[0021] Preferably, let the number of condensers be N, and the rated capacity of the condenser be Q SC , the relevant parameters of the phase regulator are configured through the following formula to increase the short-circuit ratio of the new energy station to the target value;

[0022]

[0023] in, The sign represents rounding up.

[0024] Preferably, when the short-circuit ratio of the new energy station is increased to the target value, the short-circuit ratio increase factor after configuring the phase regulator is as follows:

[0025]

[0026] The present invention is simple, easy to implement and practical. It is deduced through formulas how to configure the parameters of phase regulators in order to improve the short-circuit ratio of new energy stations. By proposing a phase regulator configuration method that takes into account the short-circuit ratio requirements of new energy stations, the short-circuit ratio of new energy stations can be reasonably and safely improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of a phase regulator configuration method in a phase regulator configuration method considering short-circuit ratio requirements of a new energy station proposed in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of connecting a phase regulator to a new energy station in a phase regulator configuration method considering the short-circuit ratio requirement of a new energy station proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0030] The present invention proposes a phase regulator configuration method that takes into account the short-circuit ratio requirements of new energy stations. The flow chart of the phase regulator configuration method is as follows: Figure 1 shown.

[0031] The specific implementation method adopted by the present invention is: a phase regulator configuration method considering the short-circuit ratio requirements of a new energy station, comprising the following steps:

[0032] Step 1: Build a mathematical model for connecting a phase regulator to a new energy station. According to the short-circuit ratio analysis method of the new energy station, the initial short-circuit ratio K of the new energy station is obtained.SCR1 And the short-circuit ratio K after the phase regulator is put into operation SCR2 , defines the increase multiple of the short-circuit ratio of the new energy station before and after the phase regulator is put into use;

[0033] Step 2, by analyzing the increase multiple of the short-circuit ratio of the new energy station, the relevant parameters of the phase regulator that affect the short-circuit ratio of the new energy station are obtained, and the relevant parameters include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator;

[0034] Step 3: According to the initial short-circuit ratio and the configured short-circuit ratio of the new energy station, the relevant parameters of the phase regulator are configured to increase the short-circuit ratio of the new energy station to the target value.

[0035] Preferably, in step 1:

[0036] Step 1.1 In a new power system dominated by renewable energy, the short-circuit ratio refers to the ratio of the system short-circuit capacity to the rated capacity of renewable energy. Assume that the equivalent reactance of the network transfer impedance of the renewable energy station is X s , the equivalent power amplitude of the new energy station system is U s , the equivalent reactance of the phase regulator is X d ", the equivalent reactance of the transformer connected to the phase regulator is X k , the internal potential of the phase regulator is E0", S N is the rated capacity of the system, and Q is the total capacity of the configured phase-shifting units.

[0037] The initial short circuit ratio is:

[0038]

[0039] Configure the short-circuit ratio as:

[0040]

[0041] Step 1.2 Define ΔK SCR Increase the short circuit ratio by multiples

[0042]

[0043] Preferably, in step 2:

[0044]

[0045] It can be concluded that the relevant parameters of the phase regulator that affect the increase in the short-circuit ratio include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator. The capacity of the phase regulator is positively correlated with the increase in the short-circuit ratio, and the equivalent impedance of the phase regulator is negatively correlated with the increase in the short-circuit ratio.

[0046] Preferably, in step 3:

[0047] Assume the number of condensers is N, the rated capacity of the condenser is Q SC , for the configuration of the phase regulator, it is necessary to meet the following requirements:

[0048]

[0049] in The sign represents rounding up.

[0050] At this time, the short-circuit ratio after configuring the phase regulator is increased by:

[0051] The example parameter values ​​are as follows: s =1,X s =1,X' d '=0.12,E0"=1.0,X k =0.2,

[0052] S N =200MVA, Q C =50MVar.

[0053] The short-circuit ratio before adding the phase regulator is:

[0054]

[0055] The short-circuit ratio after adding the phase regulator is set to increase to 1.7, and the phase regulator is configured.

[0056] According to the formula:

[0057]

[0058] It can be seen that:

[0059]

[0060] At this time, select the phase regulator rated capacity Q C =50MVar.

[0061]

[0062] That is, putting in a phase regulator with a rated capacity of 50 MVar can meet the demand, and the short-circuit ratio is increased by

[0063] The above describes the specific implementation of the present invention. It should be understood that the present invention is not limited to the above specific implementation, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other at will.

Claims

1. A phase-shifting configuration method considering the short-circuit ratio requirements of a new energy station, characterized in that: The steps include: Step 1: In the new power system with renewable energy as the main body, a mathematical model of phase regulator access to renewable energy stations is constructed. According to the short-circuit ratio analysis method of renewable energy stations, the initial short-circuit ratio K of renewable energy stations is obtained. SCR1 And the short-circuit ratio K after the phase regulator is put into operation SCR2 , defines the increase multiple of the short-circuit ratio of the new energy station before and after the phase-converter is put into use. The short-circuit ratio is used to describe the ratio of the system short-circuit capacity to the rated capacity of the new energy; Step 2, by analyzing the increase multiple of the short-circuit ratio of the new energy station, the relevant parameters of the phase regulator that affect the short-circuit ratio of the new energy station are obtained, and the relevant parameters include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator; Step 3: According to the initial short-circuit ratio and the configured short-circuit ratio of the new energy station, the relevant parameters of the phase regulator are configured to increase the short-circuit ratio of the new energy station to the target value.

2. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 1 is characterized in that: The initial short circuit ratio K SCR1 The formula is as follows: Among them, U s is the equivalent power amplitude of the new energy station system, X s To set the equivalent reactance of the transfer impedance of the new energy station network.

3. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 2 is characterized in that: The short circuit ratio K SCR2 The formula is as follows: Among them, U s is the equivalent power amplitude of the new energy station system, X s To set the equivalent reactance of the network transfer impedance of the new energy station, X d ” is the equivalent reactance of the phase regulator, X k is the equivalent reactance of the transformer connected to the phase regulator, E0” is the internal potential of the phase regulator, S N is the rated capacity of the system, and Q is the total capacity of the configured phase-shifting units.

4. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 3 is characterized in that: The short-circuit ratio of the new energy station is increased by a multiple of ΔK SCR The formula is as follows:

5. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 4 is characterized in that: The increase multiple of the short-circuit ratio of the new energy station is analyzed by the following formula: It is found that the related parameters include the rated capacity of the phase regulator and the equivalent impedance of the phase regulator. The capacity of the phase regulator is positively correlated with the increase multiple of the short-circuit ratio, and the equivalent impedance of the phase regulator is negatively correlated with the increase multiple of the short-circuit ratio.

6. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 5 is characterized in that: The number of condensers is N, and the rated capacity of the condenser is Q SC , the relevant parameters of the phase regulator are configured through the following formula to increase the short-circuit ratio of the new energy station to the target value; in, The sign represents rounding up.

7. The phase-shifting configuration method considering the short-circuit ratio requirements of new energy stations according to claim 6 is characterized in that: When the short-circuit ratio of the new energy station is increased to the target value, the short-circuit ratio increase factor after configuring the phase regulator is as follows:

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