Synchronous condenser and STATCOM configuration method, system, equipment and medium

Abstract

The present application provides a synchronous phase regulator and STATCOM configuration method, system, device, and medium. The method according to the present application includes: obtaining the minimum dynamic inductive reactive power demand of the new energy access point for preset scenarios one and two; using the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point for preset scenarios one and two as the minimum dynamic inductive reactive power demand of the new energy access point; obtaining the minimum dynamic capacitive reactive power of the new energy access point; and configuring the phase regulator and STATCOM based on the minimum dynamic inductive reactive power demand of the new energy access point, the minimum dynamic capacitive reactive power of the new energy access point, and economic efficiency. The technical solution provided by the present application can solve the problem of voltage deterioration or even instability at large new energy access points caused by sudden rise or fall of the AC side voltage of the converter station.

Description

Technical Field

[0001] This document relates to the technical field of synchronous condenser and STATCOM configuration, and in particular to a synchronous condenser and STATCOM configuration method, system, device and medium. Background Art

[0002] Large-scale new energy bases require ultra-high / ultra-high voltage transmission technology to achieve long-distance power transmission. Compared with AC transmission systems, ultra-high voltage direct current (UHVDC) transmission technology has significant advantages in large-scale, long-distance power transmission. However, ultra-high voltage direct current (UHVDC) transmission technology has the following disadvantages:

[0003] 1. When a single-pole lockout fault occurs in a UHVDC transmission system, the reactive power consumed by the converter station drops sharply, resulting in excess reactive power on the AC side, which in turn causes a sudden surge in the AC grid voltage. Furthermore, since new energy bases are often built in remote areas with weak grid structures, insufficient short-circuit capacity, and low system inertia, this voltage rise on the AC side of the converter station will further deteriorate the voltage at the grid connection point of the new energy power generation base. In severe cases, this can lead to widespread disconnection of new energy power from the grid.

[0004] 2. If a short-term fault occurs at the new energy access point or the AC side of the converter station, causing a sudden drop in system voltage, it may also cause large-scale new energy to be disconnected from the grid.

[0005] To improve the voltage stability of AC / DC systems and enhance the stable operation of the sending-end system, it is necessary to increase the reactive power reserve of the sending-end AC system, especially the dynamic reactive power reserve. Currently, common dynamic reactive power devices include synchronous condensers (SCs) and power electronic compensation devices such as static VAR compensators (SVCs) and static synchronous compensators (STATCOMs). The new generation of large-capacity condensers offers advantages such as large single-unit capacity, strong instantaneous reactive power support capability, fast transient reactive power response, and strong overload and phase-leading capabilities. They significantly enhance the system's dynamic reactive power reserve, voltage stability, and operational flexibility. SVCs, SVGs, and STATCOMs, with their high controllability and low losses, are increasingly being used in power systems.

[0006] However, while phase regulators have strong transient reactive power response capabilities, their steady-state reactive power response speed is relatively slow. Due to their mechanical properties, they are prone to system oscillations and may even cause phase regulator synchronous instability. While STATCOMs offer fast steady-state response speeds, they have weak overcurrent capabilities and are limited by voltage. Especially when system voltage is insufficient, the reactive power they can generate decreases with the voltage drop, potentially leading to grid disconnection, further deteriorating system voltage. Using power electronic reactive power compensation devices like STATCOMs or synchronous phase regulators alone cannot fully address the need for voltage stability. Summary of the Invention

[0007] The present invention provides a synchronous phase condenser and STATCOM configuration method, system, equipment and medium, which can not only solve the transient reactive power demand, but also meet the steady-state rapid and stable reactive power demand.

[0008] An embodiment of the present invention provides a synchronous condenser and a STATCOM configuration method, including:

[0009] S1. Obtain the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2, and use the maximum value of the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2 as the minimum dynamic inductive reactive power requirement of the new energy access point;

[0010] S2. Obtaining the minimum dynamic capacitive reactive power of the new energy access point; and

[0011] S3. Configuring the synchronous condenser and the STATCOM according to the minimum dynamic inductive reactive power demand of the new energy access point, the minimum dynamic capacitive reactive power of the new energy access point, and economy;

[0012] The first preset scenario is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, which further causes overvoltage at the new energy access point;

[0013] The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

[0014] An embodiment of the present invention provides a synchronous condenser and STATCOM configuration system, including:

[0015] A minimum dynamic inductive reactive power demand acquisition module is configured to acquire the minimum dynamic inductive reactive power demand of the new energy access point in preset scenarios 1 and 2, and use the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scenarios 1 and 2 as the minimum dynamic inductive reactive power demand of the new energy access point;

[0016] A minimum dynamic capacitive reactive power module for obtaining the minimum dynamic capacitive reactive power of a new energy access point; and

[0017] A synchronous condenser and STATCOM configuration module, configured to configure the condenser and STATCOM according to the minimum dynamic inductive reactive power demand of the renewable energy access point, the minimum dynamic capacitive reactive power of the renewable energy access point, and economy;

[0018] The first preset scenario is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, which further causes overvoltage at the new energy access point;

[0019] The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

[0020] An embodiment of the present invention further provides an electronic device, including:

[0021] processor; and,

[0022] A memory is arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps of the synchronous condenser and STATCOM configuration method as described above.

[0023] An embodiment of the present invention further provides a storage medium for storing computer-executable instructions, wherein the computer-executable instructions, when executed, implement the steps of the above-mentioned synchronous condenser and STATCOM configuration method.

[0024] By adopting the embodiments of the present invention, based on the sudden rise and fall in voltage at the renewable energy access point caused by a converter station failure, the system's dynamic reactive power demand is calculated and simulated, and the capacity of the hybrid phase-shifting system (phase-shifting system and STATCOM) is configured accordingly, resulting in a capacity that is closer to the system demand. In the prior art, when selecting dynamic reactive power compensation equipment, either phase-shifting system or power electronic reactive power equipment is selected, and a combination of the two is rarely used. In the rare cases where both are configured together, the other type of equipment is considered only when a single device cannot meet the requirements. This lacks overall planning and makes it difficult to achieve an optimized configuration. Phase-shifting system has strong transient reactive power capability but is subject to mechanical oscillation. STATCOM has a fast and stable reactive power response but weak overcurrent capability, causing it to disconnect from the grid when the voltage drops below 0.4 pu or rises above 1.3 pu, thereby worsening the system voltage. The present invention fully considers the advantages of both and strives to prevent voltages from dropping below 0.4 pu or rising above 1.3 pu, preventing STATCOM disconnection and ensuring that the STATCOM's effect is positive throughout the transient process, helping the phase-shifting system quickly restore the system voltage and reducing phase-shifting oscillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 Flowchart of a synchronous condenser and STATCOM configuration method according to an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a synchronous condenser and STATCOM configuration system according to an embodiment of the present invention;

[0028] Figure 3 A simplified system diagram and approximate equivalent diagram of a new energy access point connected to a UHV converter station according to an embodiment of the present invention;

[0029] Figure 4 This is a flow chart of inductive reactive power simulation calculation according to an embodiment of the present invention;

[0030] Figure 5 This is a flow chart of capacitive reactive power simulation calculation according to an embodiment of the present invention;

[0031] Figure 6 A diagram showing a hybrid phase regulator access system according to an embodiment of the present invention;

[0032] Figure 7 This is a typical UI curve diagram of a STATCOM according to an embodiment of the present invention;

[0033] Figure 8 This is a flow chart of a solution for adjusting a hybrid phase regulator through simulation calculation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this document.

[0035] Method Example

[0036] According to an embodiment of the present invention, a synchronous condenser and a STATCOM configuration method are provided. Figure 1 This is a flow chart of a synchronous condenser and STATCOM configuration method according to an embodiment of the present invention. Figure 1 The synchronous condenser and STATCOM configuration method of the embodiment of the present invention specifically includes:

[0037] S1. Obtain the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2, and use the maximum value of the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2 as the minimum dynamic inductive reactive power requirement of the new energy access point;

[0038] The first preset scenario is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, which further causes overvoltage at the new energy access point;

[0039] The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

[0040] The step of obtaining the minimum dynamic inductive reactive power requirement of the new energy access point in the preset scenario 1 specifically includes:

[0041] Calculate the reactive power surplus of the system caused by the filter in the converter station not being able to exit in time, which causes the AC side voltage of the converter station to rise to U 1max ;

[0042] According to the voltage U 1max , calculate the voltage U at the new energy access point 2max(1) ;

[0043] Calculate the voltage U at the new energy access point 2max(1) Reduce to the maximum allowable voltage U 2Tmax The minimum dynamic reactive power S required L1 .

[0044] S L1 The specific analysis and calculation process is as follows:

[0045] The ultra-high voltage transmission line between the new energy access point and the ultra-high voltage DC converter station is generally no more than 1000km, which can be represented by a π-type equivalent circuit diagram. In order to avoid line no-load overvoltage, equivalent reactors are installed at both ends of the line for compensation. After the reactor compensation, the transmission line can be approximately represented as Figure 3 The one-line equivalent circuit diagram shown.

[0046] The AC bus voltage of the converter station is the reference voltage, which is equal to the high-voltage bus voltage at the new energy access point. The relationship is as follows:

[0047]

[0048] In the above formula: U1 is the AC bus voltage of the converter station P1 and Q1 are the active power and reactive power flowing into the AC bus side of the converter station respectively; R and X are the resistance and reactance of the line respectively.

[0049] The power at both ends of the transmission line is related as follows:

[0050]

[0051] In the above formula: U2 is the high-voltage side bus voltage of the new energy access point P2 and Q2 are the active power and reactive power flowing out of the high-voltage side busbar of the renewable energy access point, respectively; R and X are the resistance and reactance of the line, respectively.

[0052] During normal operation, to reduce power losses in the transmission line, the reactive power output of the new energy access point should be minimized. When the transmission line does not transmit reactive power to the converter station, that is, when Q1 = 0, the minimum reactive power output of the new energy access point is achieved. Since the resistance R of the ultra-high voltage line is very small, the loss of a 100-meter transmission line is about 0.6%, so the line loss can be ignored. Equation (1) can be modified to:

[0053]

[0054] Scenario 1: Commutation failure occurs at the converter station. Since the filter in the station fails to exit in time, the system has reactive power surplus and the voltage on the AC side of the converter station rises to U 1max At the same time, the AC busbar feeds reactive power back to each transmission line, further increasing the voltage at the renewable energy access point. Taking the partial derivative of U1 and Q1 from equation (1), we get:

[0055]

[0056] Since the AC side system of the converter station is very complex, the distribution of the residual reactive power and the voltage increase value of the converter station are related to the AC side system. Therefore, it is necessary to simulate the entire AC side system to calculate the voltage of the new energy access point. According to the simulation calculation, the voltage U 2max(1) , reduce the voltage at the new energy access point to the maximum allowable voltage U 2Rmax , that is, the voltage that needs to be reduced at the new energy access point is (U 2max(1) -U 2Rmax ).

[0057] Ignoring the impact of line reactive power output on active power loss, the relationship between the reactive power changes at the beginning and end of the line is as follows:

[0058]

[0059] In the above formula: dQ1 and dQ2 are the reactive increments of Q1 and Q2 respectively;

[0060] Ignoring the influence of the terminal reactive input on the head-end voltage, substituting equation (5) into equation (4) yields:

[0061]

[0062] The above formula: for The voltage increment.

[0063] Ignoring the voltage transverse component (imaginary part of the voltage), the terminal voltage increment is:

[0064]

[0065] Above: U 2Rmax is the maximum allowable voltage of the new energy access point; U 2max(1) It is the maximum fault voltage at the renewable energy access point under scenario 1 (commutation failure at the converter station).

[0066] Therefore, it can be estimated that the inductive reactive power demand of the new energy access point is approximately:

[0067]

[0068] The above formula: ΔQ2 is the voltage U from the new energy access point 2max(1) Down to U 2Rmax Required inductive reactive power; U 1max is the highest voltage of the AC bus of the converter station after the commutation failure; Q2 is the initial reactive component flowing out of the high-voltage side bus of the new energy access point.

[0069] At the same time, considering that before the commutation failure of the converter station, the new energy access point was running at full load and all the capacitors in the station were put into operation, when the voltage at the new energy access point increased, the reactive power output of the capacitors would also increase. Therefore, the dynamic inductive reactive power invested also needs to compensate for this part of the reactive power increase. Therefore, the minimum dynamic inductive reactive power capacity invested is at least:

[0070]

[0071] The above formula: S L1 is the minimum dynamic inductive reactive capacity requirement in scenario 1; U2 is the voltage amplitude of the new energy access point during normal operation, U 2N Its rated voltage, U 2Rmax is the maximum allowable voltage of the new energy access point, S CN is the total capacity of the compensation capacitor invested in the new energy access point; Q2 is the inductive reactive power demand of the new energy access point calculated by formula (8).

[0072] Obtaining the minimum dynamic inductive reactive power requirement of the new energy access point in preset scenario 2 specifically includes:

[0073] Get the minimum allowable voltage U when all static capacitive reactive equipment in the station are put into operation before the fault is cleared 2Rmin ;

[0074] At the moment of fault clearing, due to the sudden change of voltage, the reactive output of static capacitive reactive equipment increases suddenly, resulting in a reactive surplus in the system. The voltage at the new energy access point rises to U 2max(2) ;

[0075] Calculate the voltage U at the new energy access point 2max(2) Reduce to the maximum allowable voltage U 2Rmax The minimum dynamic reactive power S required L2 .

[0076] S L2 The specific analysis and calculation process is as follows:

[0077] The fault on the AC side of the converter station causes low voltage at the PCC point. All static capacitive reactive power in the station is put into use to increase the voltage. At the moment the fault is restored, the static capacitive reactive power has no time to exit, and the system reactive power remains, causing transient overvoltage.

[0078] The maximum change of static capacitive reactive power in this process is from the system minimum operating voltage U 2Rmin Run to the maximum allowable voltage U 2Rmax ,Right now: Inductive reactive power can compensate for this part of the capacitive reactive power increase, which can solve the overvoltage steady state. In addition, as long as the reactive capacity generated by these static capacitive reactive devices is completely offset, the overvoltage can also be controlled. Therefore, the dynamic inductive reactive power input can be taken as the minimum value of the two.

[0079]

[0080] The above formula: S L2 is the minimum reactive power demand of the PCC point in scenario 2, U 2Rmax and U 2Rmin are the maximum and minimum allowable voltages at the PCC point; U 2N is the rated voltage of PCC point; S CN It is the total capacity of the compensation capacitors used at the PCC point.

[0081] Determine the minimum dynamic inductive reactive power demand S at the PCC point L :

[0082] First, according to S L1 and S L2 , determine the minimum dynamic inductive reactive power demand (calculated value) of the PCC point, that is:

[0083] S L =max{S L1 , S L2} (11);

[0084] The above formula: S L is the calculated value of the minimum dynamic inductive reactive power demand at the PCC point, S L1 and S L2 These are the calculated values of the minimum dynamic reactive power demand of the PCC point for preset scenarios 1 and 2, respectively.

[0085] Then, use the simulation software to perform a one-step verification and make appropriate adjustments. The fine-tuning of the simulation software is carried out in two steps: the first step is to fine-tune the calculated value of the inductive reactive capacity if it is too small, and obtain the minimum dynamic inductive capacity through simulation approximation. See the flow chart for details. Figure 4 The second step is to fine-tune the calculated value of inductive reactive capacity which is too large (the constraint of the first step of simulation has been satisfied through simulation) and reduce the dynamic inductive reactive compensation amount by stepwise approximation. See the flowchart for details. Figure 4 The right side of the figure.

[0086] S2. Obtain the minimum dynamic capacitive reactive power of the new energy access point. S2 specifically includes:

[0087] Calculate the voltage U at the new energy access point when a three-phase short circuit fault occurs on the AC side bus of the converter station 2min ;

[0088] Calculate the voltage U at the point where the new energy is connected 2min Increase to the minimum dynamic capacitive reactive power S when both the new energy unit and STATCOM are running without disconnecting from the grid C ;

[0089] S C As the minimum dynamic capacitive reactive power of the new energy access point.

[0090] S C The specific analysis and calculation process is as follows:

[0091] When a short-term three-phase short-circuit fault occurs on the AC side busbar of the converter station, the new energy unit will not be disconnected from the grid and will provide short-circuit current to the fault point. Ignoring the influence of the resistance of the transmission line, the voltage at the PCC point is approximately:

[0092]

[0093] The above formula: S 2W is the short-circuit capacity of the PCC point, X is the reactance of the transmission line from the PCC point to the converter station; U 1N is the rated voltage of PCC point; U 2min It is the voltage at the PCC point (also its minimum voltage) when a three-phase short circuit fault occurs in the converter station.

[0094] To raise the PCC point voltage to the minimum voltage U 2Rmin , the short-circuit current that needs to be increased is:

[0095]

[0096] Above: U 2Rmin is the minimum allowable voltage at the PCC point, U 2minis the minimum fault voltage at the PCC point; dI2 is the additional short-circuit current required to raise the PCC point voltage to the minimum allowable voltage;

[0097] The capacitive reactive power that needs to be increased is:

[0098]

[0099] The above formula: S C It is the calculated value of the minimum dynamic capacitive reactive capacity of the PCC point.

[0100] After completing the above estimation, use simulation software to verify. When the capacitive compensation is insufficient and cannot meet the voltage requirements, gradually increase the reactive capacity. When the capacitive compensation is excessive and the compensation voltage is greater than the set threshold (U 2Rmin +C), gradually reduce the capacity setting value, the capacitive reactive power simulation calculation flow chart is as follows Figure 5 shown.

[0101] S3. Configuring the synchronous condenser and STATCOM based on the minimum dynamic inductive reactive power demand of the new energy access point, the minimum dynamic capacitive reactive power of the new energy access point, and economy. S3 specifically includes:

[0102] S31. Analyze the relationship between the transient reactive output and the steady-state output of the synchronous condenser and the STATCOM in the preset scenario 1 and the preset scenario 2, obtain the output coefficient, determine the minimum capacity of the synchronous condenser and the STATCOM that meets the instantaneous capacitive and inductive reactive power requirements based on the output coefficient, and select the synchronous condenser and the STATCOM with the closest capacity from the existing equipment system based on the minimum capacity of the synchronous condenser and the STATCOM;

[0103] S32. Use simulation software to verify and adjust the synchronous phase condenser and STATCOM configuration plan, and determine the final plan.

[0104] The system diagram of hybrid phase regulator connected to PCC point is as follows Figure 6 As shown, usually the synchronous phase regulator and STATCOM do not share the boost transformer, and the capacity of the boost transformer matches the capacity of the connected phase regulator and STATCOM.

[0105] S31 specifically includes:

[0106] The current delivered by the condenser to the PCC point can be expressed as follows:

[0107]

[0108] The above formula: E q is the excitation voltage; U s is the PCC point voltage, X TThe system reactance from the SC to the PCC point is mainly the step-up transformer reactance, X d is the equivalent steady-state reactance of the phase regulator. After entering the transient state, the reactance of the phase regulator drops to the sub-transient reactance X” d .

[0109] Scenario 1: Consider the state of the condenser before the inverter commutation fails is no-load state, that is, E q =U s ≈U 2N , commutation fails, the voltage at PCC point rises, the current of the phase regulator in formula (15) is negative, absorbing reactive power from the system, and the instantaneous inductive reactive power transmitted to PCC point is approximately:

[0110]

[0111] The above formula: Q L_SG is the inductive reactive power delivered to the PCC point by the phase regulator; S SG is the capacity of the condenser, k L1 is the inductive reactive output coefficient of the camera in scene 1, U 2N is the rated voltage of PCC point; U 2Rmax is the maximum allowable operating voltage of the PCC point; X T is the system reactance from the condenser to the PCC point; X d is the equivalent reactance of the phase regulator.

[0112] In scenario two, since it is a short-term fault, the phase regulator excitation system has not yet been activated, that is, the fault is restored, and the excitation voltage of the phase regulator is consistent with scenario one. If the system recovers quickly, the phase regulator may still be in a transient state, and the reactance is smaller than that in the steady state, and it can generate more reactive power than in scenario one, which is beneficial to system recovery. (For non-transient short-circuit faults, due to the long fault time, the phase regulator excitation system is activated. When the system recovers, it is necessary to coordinate and control the phase regulator excitation system to avoid overvoltage caused by overshoot of the phase regulator. This scenario involves the coordinated control of the phase regulator and STATCOM, which is not within the research scope of this invention.) Therefore, in scenario two, the phase regulator can generate more reactive power than in scenario one, that is, the configuration according to the situation of scenario one can meet the requirements of scenario two.

[0113] STATCOM can usually continuously adjust the current to generate continuously adjustable reactive power when the system voltage is between 0.9 and 1.1 pu. When the voltage is between 0.4 and 0.9 pu, it works at the maximum rated capacitive current, and the reactive power generated is proportional to the voltage. When the voltage is between 1.1 and 1.3 pu, it works at the maximum inductive current, and the reactive power generated is proportional to the voltage. However, it will be disconnected from the grid when the voltage is lower than 0.4 pu or the high voltage is 1.3 pu. The typical UI curve of STATCOM is shown in Figure 1. Figure 7 .

[0114] In both scenarios 1 and 2, the maximum inductive reactive power that STATCOM can generate is:

[0115]

[0116] The above formula: Q L_ST S is the inductive reactive power transmitted from STATCOM to PCC point; ST is the capacity of STATCOM; U 2Rmax is the maximum operating voltage of the PCC point, U 2N is the rated voltage of PCC point; I ST_N is the rated current of STATCOM; k L2 is the inductive reactive power output coefficient of STATCOM in scenario 1,

[0117] The maximum instantaneous capacitive reactive power of the phase regulator and STATCOM is for when a short circuit fault occurs on the AC side of the converter station, and the system voltage is stabilized at U under the action of the dynamic reactive equipment. 2Rmin Without considering the excitation action of the phase regulator, and considering that the phase regulator is running in a no-load state before the fault, the instantaneous reactive power of the phase regulator is:

[0118]

[0119] The above formula: Q C_SG is the instantaneous capacitive reactive power of the phase regulator when a short circuit occurs in the converter station; X″ d is the subtransient reactance of the condenser, X T U is the system reactance from the condenser to the PCC point; 2Rmin and U 2N are the minimum operating voltage and rated voltage of PCC point respectively; S SG is the rated capacity of the phase regulator; k C1 is the capacitive reactive power output coefficient of the phase regulator,

[0120] STATCOM emits the maximum capacitive current, and the power it emits is related to the voltage:

[0121]

[0122] The above formula: Q ST is the instantaneous capacitive reactive power of STATCOM when a short circuit occurs in the converter station; U 2Rmin and U 2N are the minimum operating voltage and rated voltage of PCC point respectively; I ST_N is the rated current of STATCOM; S ST is the capacity of STATCOM; kC2 is the capacitive reactive output coefficient of STATCOM,

[0123] In formulas (18) and (19), k C1 and k C2 are the reactive output coefficients of the condenser and STATCOM during fault conditions, respectively.

[0124] Phase regulators and STATCOMs need to meet the PCC point's requirements for dynamic capacitive and inductive reactive power, namely:

[0125]

[0126] The above formula: k L1 and k L2 are the inductive reactive output coefficients of the phase regulator and STATCOM after the fault, which are calculated by equations (16) and (17) respectively; k C1 and k C2 are the capacitive reactive output coefficients of the phase regulator and STATCOM after the fault, which are calculated by equations (18) and (19) respectively; S SG and S ST are the capacities of the condenser and STATCOM respectively; S L and S C They are the minimum dynamic inductive reactive power demand capacity and the minimum capacitive reactive power demand capacity of the PCC point respectively.

[0127] According to the existing manufacturing equipment, the phase regulator and STATCOM with the minimum capacity that meets equation (20) are selected, and the corresponding step-up transformer model is determined.

[0128] S32 specifically includes:

[0129] Use simulation software to verify and adjust the configured hybrid phase regulator and determine the final solution.

[0130] Use simulation equipment to simulate and verify the configured hybrid phase condenser solution: verify each scenario separately. If it cannot meet the requirements, consider increasing the capacity of the phase condenser or STATCOM. See the flow chart for details. Figure 8 Since the output delay of the phase regulator and STATCOM is not considered during the estimation, the selected solution is often too small in capacity, so there is no need to consider the simulation adjustment solution set due to capacity transition.

[0131] The present invention provides a hybrid phase regulator and STATCOM configuration technology, which aims to solve the problem of voltage deterioration or even instability at large-scale renewable energy access points caused by sudden rise or drop in AC side voltage of converter stations.

[0132] A hybrid phase-shifting system configuration technology applied to large-scale renewable energy access points has the following improvements: it can comprehensively utilize the dynamic reactive power compensation advantages of the phase-shifting system and STATCOM, and can use the phase-shifting system's super-strong transient reactive power compensation capability to quickly restore voltage and enable the STATCOM to operate normally without being disconnected from the grid; in the steady-state and fault recovery periods, it can use the STATCOM's fast reactive power response capability to quickly restore voltage and reduce the mechanical oscillation of the phase-shifting system.

[0133] By adopting the embodiments of the present invention, the following beneficial effects are achieved:

[0134] The configuration of existing phase-shifting converters or power electronic reactive equipment is a posteriori, that is, they are configured first and then verified to see if they can meet the requirements, which easily leads to transitional configurations. The present invention calculates and simulates the system's demand for dynamic reactive power based on the sudden rise and fall of voltage at the PCC point caused by a fault in the converter station, and configures the capacity of the hybrid phase-shifting converter accordingly. The configured capacity is closer to the system demand.

[0135] In the existing technology, when selecting dynamic reactive power compensation equipment, either a phase regulator or a power electronic reactive power device is selected. It is rare to combine the two. Even if the two are combined, the other type of equipment is considered only when a single device cannot meet the requirements. Therefore, there is a lack of overall planning, and it is difficult to achieve an optimized configuration.

[0136] While condensers have strong transient reactive power, they are subject to mechanical oscillations. STATCOMs have a fast and stable reactive power response, but weak overcurrent capability. They can disconnect from the grid when voltage drops below 0.4 pu or rises above 1.3 pu, worsening system voltage. This invention leverages the advantages of both, minimizing voltage drops below 0.4 pu or rises above 1.3 pu, thereby preventing STATCOM disconnection. This ensures that the STATCOM maintains a positive effect throughout the transient process, assisting the condenser in rapidly restoring system voltage and reducing oscillations.

[0137] System Example

[0138] According to an embodiment of the present invention, a synchronous condenser and STATCOM configuration system is provided. Figure 2 The synchronous condenser and STATCOM configuration system diagram of the embodiment of the present invention is shown in FIG. Figure 2 The synchronous condenser and STATCOM configuration system of the embodiment of the present invention specifically includes:

[0139] The minimum dynamic inductive reactive power demand acquisition module 20 is configured to acquire the minimum dynamic inductive reactive power demand of the new energy access point in the preset scenario 1 and the preset scenario 2, and use the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in the preset scenario 1 and the preset scenario 2 as the minimum dynamic inductive reactive power demand of the new energy access point;

[0140] The minimum dynamic capacitive reactive power module 22 is used to obtain the minimum dynamic capacitive reactive power of the new energy access point; and

[0141] A synchronous condenser and STATCOM configuration module 24 is configured to configure the condenser and STATCOM according to the minimum dynamic inductive reactive power demand of the renewable energy access point, the minimum dynamic capacitive reactive power of the renewable energy access point, and the economy;

[0142] The first preset scenario is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, which further causes overvoltage at the new energy access point;

[0143] The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

[0144] This system embodiment is a system embodiment that corresponds one-to-one to the above method embodiment. For the specific implementation of each module in this embodiment, please refer to the above method embodiment and will not be repeated here.

[0145] Device Example 1

[0146] According to an embodiment of the present invention, an electronic device is provided, including:

[0147] processor; and,

[0148] A memory is arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps as described in the above method embodiment.

[0149] Device Example 2

[0150] According to an embodiment of the present invention, a storage medium is provided for storing computer-executable instructions, wherein the computer-executable instructions implement the steps described in the above method embodiment when executed.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A synchronous condenser and STATCOM configuration method, characterized in that include: S1. Obtain the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2, and use the maximum value of the minimum dynamic inductive reactive power requirements of the new energy access point for preset scenarios 1 and 2 as the minimum dynamic inductive reactive power requirement of the new energy access point; S2. Obtaining the minimum dynamic capacitive reactive power of the new energy access point; and S3. Configuring the synchronous condenser and the STATCOM according to the minimum dynamic inductive reactive power demand of the new energy access point, the minimum dynamic capacitive reactive power of the new energy access point, and economy; The first preset scenario is that due to commutation failure or unipolar blocking, the AC side voltage of the converter station rises, causing overvoltage at the new energy access point; The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

2. The method according to claim 1, characterized in that The step of obtaining the minimum dynamic inductive reactive power requirement of the new energy access point in the preset scenario 1 specifically includes: Calculate the reactive power surplus of the system caused by the filter in the converter station not being able to exit in time, which causes the AC side voltage of the converter station to rise to U 1max ; According to the voltage U 1max , calculate the voltage U at the new energy access point 2max(1) ; Calculate the voltage U at the new energy access point 2max(1) Reduce to the maximum allowable voltage U 2Rmax The minimum dynamic reactive power S required L1 .

3. The method according to claim 1, characterized in that The step of obtaining the minimum dynamic inductive reactive power requirement of the new energy access point in the preset scenario 2 specifically includes: Get the minimum allowable voltage U when all static capacitive reactive equipment in the station are put into operation before the fault is cleared 2Rmin ; At the moment of fault clearing, due to the sudden change of voltage, the reactive output of static capacitive reactive equipment increases suddenly, resulting in a reactive surplus in the system. The voltage at the new energy access point rises to U 2max(2) ; Calculate the voltage U at the new energy access point 2max(2) Reduce to the maximum allowable voltage U 2Rmax The minimum dynamic reactive power S required L2 .

4. The method according to claim 1, wherein The obtaining of the minimum dynamic capacitive reactive power of the new energy access point specifically includes: Calculate the voltage U at the new energy access point when a three-phase short circuit fault occurs on the AC side bus of the converter station 2min ; Calculate the voltage U at the point where the new energy is connected 2min Increase to the minimum dynamic capacitive reactive power S when both the new energy unit and STATCOM are running without disconnecting from the grid C ; S C As the minimum dynamic capacitive reactive power of the new energy access point.

5. The method according to claim 1, wherein The S3 specifically includes: S31. Analyze the relationship between the transient reactive output and the steady-state output of the synchronous condenser and the STATCOM in the preset scenario 1 and the preset scenario 2, obtain the output coefficient, determine the minimum capacity of the synchronous condenser and the STATCOM that meets the capacitive and inductive instantaneous reactive power requirements based on the output coefficient, and set the synchronous condenser and STATCOM configuration plan based on the minimum capacity of the synchronous condenser and the STATCOM; S32. Use simulation software to verify and adjust the synchronous condenser and STATCOM configuration scheme.

6. The method according to claim 5, characterized in that The S31 specifically includes: The transient inductive reactive power in the preset scenario 1 is obtained by formula 1: Among them, Q L_SG is the inductive reactive power delivered by the synchronous condenser to the renewable energy access point; S SG is the capacity of the synchronous condenser, k L1 is the inductive reactive power output coefficient of the synchronous condenser in the preset scenario, U 2N is the rated voltage of the new energy access point; U 2Rmax is the maximum allowable operating voltage of the new energy access point; X T The system reactance from the synchronous condenser to the new energy access point; X d is the equivalent reactance of the synchronous condenser; The maximum inductive reactive power generated by STATCOM in preset scenarios 1 and 2 is obtained by formula 2: Among them, Q L_ST The inductive reactive power transmitted by STATCOM to the new energy access point; S ST is the capacity of STATCOM; U 2Rmax is the maximum operating voltage of the new energy access point, U 2N is the rated voltage of the new energy access point; I ST_N is the rated current of STATCOM; k L2 is the inductive reactive power output coefficient of STATCOM in the preset scenario, The instantaneous reactive power of the synchronous condenser is: Among them, Q C_SG is the instantaneous capacitive reactive power of the synchronous condenser when a short circuit occurs in the converter station; X″ d is the subtransient reactance of the synchronous condenser, X T U is the system reactance from the synchronous condenser to the new energy access point; 2Rmin and U 2N are the minimum operating voltage and rated voltage of the new energy access point respectively; S SG is the rated capacity of the synchronous condenser; k C1 is the capacitive reactive power output coefficient of the synchronous condenser, STATCOM emits the maximum capacitive current, and the power it emits is related to the voltage: Among them, Q ST is the instantaneous capacitive reactive power of STATCOM when a short circuit occurs in the converter station; U 2Rmin and U 2N are the minimum operating voltage and rated voltage of the new energy access point respectively; I ST_N is the rated current of STATCOM; S ST is the capacity of STATCOM; k C2 is the capacitive reactive output coefficient of STATCOM, The synchronous condenser and STATCOM need to meet the requirements of the new energy access point for dynamic capacitive reactive power and inductive reactive power through formula 5. Among them, k L1 and k L2 are the inductive reactive output coefficients of synchronous condenser and STATCOM after fault respectively; k C1 and k C2 are the capacitive reactive power output coefficients of synchronous condenser and STATCOM after fault respectively; S SG and S ST are the capacities of synchronous condenser and STATCOM respectively; S L and S C They are the minimum dynamic inductive reactive power demand capacity and the minimum capacitive reactive power demand capacity of the new energy access point respectively.

7. The method according to claim 5, characterized in that The S32 specifically includes: According to the synchronous condenser and STATCOM configuration scheme, the preset scenario 1 and the preset scenario 2 are respectively verified. If the preset requirements cannot be met, the capacity of the synchronous condenser or STATCOM is increased.

8. A synchronous condenser and STATCOM configuration system, characterized in that: include: A minimum dynamic inductive reactive power demand acquisition module is configured to acquire the minimum dynamic inductive reactive power demand of the new energy access point in preset scenarios 1 and 2, and use the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scenarios 1 and 2 as the minimum dynamic inductive reactive power demand of the new energy access point; Minimum dynamic capacitive reactive power module, used to obtain the minimum dynamic capacitive reactive power of the new energy access point; as well as, A synchronous condenser and STATCOM configuration module, configured to configure the condenser and STATCOM according to the minimum dynamic inductive reactive power demand of the renewable energy access point, the minimum dynamic capacitive reactive power of the renewable energy access point, and economy; The first preset scenario is that due to commutation failure or unipolar blocking, the AC side voltage of the converter station rises, causing overvoltage at the new energy access point; The preset scenario 2 is that the transient voltage at the new energy access point is too high due to excessive reactive power input during a fault.

9. An electronic device comprising: processor; as well as, A memory arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps of the synchronous condenser and STATCOM configuration method according to any one of claims 1 to 8.

10. A storage medium for storing computer-executable instructions, wherein the computer-executable instructions, when executed, implement the steps of the synchronous condenser and STATCOM configuration method according to any one of claims 1 to 8.

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