Synchronous phase modifier, STATCOM configuration method, system, device and medium

Abstract

The invention provides a synchronous phase modifier and STATCOM configuration method, system and device, and a medium. The method according to the invention comprises the following steps: obtaining the minimum dynamic perceptual reactive power demand of new energy access points of a preset scene I and a preset scene II; taking the maximum value of the minimum dynamic perceptual reactive power requirements of the new energy access points in the preset scene I and the preset scene II as the minimum dynamic perceptual reactive power requirements of the new energy access points; obtaining the minimum dynamic capacitive reactive power of the new energy access point; and configuring the phase modifier and the STATCOM according to the minimum dynamic inductive reactive power demand of the new energy access point and the minimum dynamic capacitive reactive power and economical efficiency of the new energy access point. According to the technical scheme provided by the invention, the problem of voltage deterioration and even instability of the large new energy access point caused by sudden rise or sudden drop of the alternating current side voltage of the converter station can be solved.

Description

Technical Field

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

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

[0003] 1. When a single-pole locking fault occurs in the UHV DC transmission system, the reactive power consumed by the converter station drops sharply, resulting in excess reactive power on the AC side, which causes a sudden rise in the AC grid voltage. At the same time, since new energy bases are often built in remote areas, the grid structure is weak, the short-circuit capacity is insufficient, and the system inertia is small, the voltage rise on the AC side of the converter station will cause the voltage at the grid connection point of the new energy power generation base to further deteriorate, and in severe cases, it may cause a large area of ​​new energy to be disconnected 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 a large area of ​​new energy to be disconnected from the grid.

[0005] In order to improve the voltage stability of AC / DC systems and enhance the stable operation capability of the sending-end system, it is objectively necessary to improve the reactive power reserve of the sending-end AC system, especially the dynamic reactive power reserve. At present, the common dynamic reactive power equipment is mainly synchronous phase regulator SC and power electronic compensation equipment represented by static VAR compensator SVC and static synchronous compensator STATCOM. The new generation of large-capacity phase regulator has the advantages of large single-unit capacity, strong instantaneous reactive power support capability, fast transient reactive power response, strong overload and phase leading capability, etc., which plays a significant role in improving the dynamic reactive power reserve, voltage stability and operation flexibility of the system. SVC, SVG and STATCOM have the advantages of high controllability and low loss, and their application in power systems is also increasing.

[0006] However, although the phase regulator has a strong transient reactive power response capability, its steady-state reactive power response speed is relatively slow, and due to its mechanical properties, it is easy to cause system oscillation and may even cause phase regulator synchronization instability. Although STATCOM has a fast steady-state response speed, its overcurrent capacity is weak and is limited by voltage. Especially when the system voltage is insufficient, the reactive power that can be generated will decrease with the voltage drop, or even disconnect from the grid, which will further deteriorate the system voltage. Using power electronic reactive power compensation equipment such as STATCOM or synchronous phase regulator alone cannot solve the full range of voltage stability needs. 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 and temporary reactive power demand, but also meet the steady-state rapid and stable reactive power demand.

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

[0009] S1, obtaining the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2, and taking the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2 as the minimum dynamic inductive reactive power demand of the new energy access point;

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

[0011] S3. 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 the economy, the synchronous condenser and the STATCOM are configured;

[0012] The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and 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 the fault period.

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

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

[0016] A minimum dynamic capacitive reactive power module, used to obtain the minimum dynamic capacitive reactive power of the 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 new energy access point, the minimum dynamic capacitive reactive power of the new energy access point and the economy;

[0018] The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and 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 the fault period.

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

[0021] processor; and,

[0022] 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 as described above.

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

[0024] By adopting the embodiment of the present invention, based on the sudden rise and fall of the voltage at the new energy access point caused by the fault of the converter station, the system's demand for dynamic reactive power is obtained through calculation and simulation, and the capacity of the hybrid phase regulator (phase regulator and STATCOM) is configured accordingly, and the configured capacity is closer to the system demand. In the prior art, when selecting dynamic reactive power compensation equipment, either phase regulator or power electronic reactive equipment is selected, and the two are rarely configured together; the rare configuration of the two together is also when a single device cannot meet the requirements, and then consider configuring another type of equipment, so there is a lack of overall planning, and it is difficult to achieve a configuration optimization. The transient reactive power of the phase regulator is strong, but there is mechanical oscillation. The reactive power response of STATCOM is fast and stable, but the overcurrent capacity is weak. When the voltage is lower than 0.4pu or higher than 1.3pu, it will be disconnected from the grid, but worsen the system voltage; the present invention fully considers the advantages of both, and strives to avoid the voltage being lower than 0.4pu or higher than 1.3pu, avoid STATCOM disconnection, ensure that the role of STATCOM in the entire transient process is positive, assist the phase regulator to quickly restore the system voltage, and reduce the oscillation of the phase regulator. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

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

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

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

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

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

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

[0032] Figure 7 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 by 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 following will be combined with the drawings in one or more embodiments of this specification to clearly and completely describe the technical solutions 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 creative work should fall within the scope of protection of this document.

[0035] Method Embodiment

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

[0037] S1, obtaining the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2, and taking the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2 as the minimum dynamic inductive reactive power demand of the new energy access point;

[0038] The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and 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 the fault period.

[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, thus causing the voltage on the AC side 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 permissible 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] The above formula: U 1 is the AC bus voltage of the converter station The voltage amplitude; P 1 and Q 1 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] The above formula: U 2 The high-voltage bus voltage at the new energy access point The voltage amplitude; P 2 and Q 2 are the active power and reactive power flowing out of the high-voltage side bus of the renewable energy access point; R and X are the resistance and reactance of the line respectively.

[0052] In normal operation, in order to reduce the power loss of the transmission line, the reactive power output of the new energy access point should be reduced as much as possible. When the transmission line does not transmit reactive power to the converter station, that is, Q 1 = 0 is the minimum reactive power output of the new energy access point. 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. Formula (1) can be corrected as:

[0053]

[0054] Scenario 1: Commutation failure occurs in 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 sends reactive power to each transmission line, further increasing the voltage at the new energy access point. 1 and Q 1 Taking partial derivatives, 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 transmission on active power loss, the relationship between the reactive power changes at the beginning and end of the line is as follows:

[0058]

[0059] The above formula: dQ 1 and dQ 2 Q 1 and Q 2 The reactive power increase;

[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] The above formula: U 2Rmax is the maximum allowable voltage at 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 occurs in 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: ΔQ 2 For the new energy access point, the voltage U 2max(1) Down to U 2Rmax Required inductive reactive power; U 1max The maximum voltage of the AC busbar of the converter station after the commutation failure; Q 2 They are the initial reactive components flowing out of the high-voltage side busbar of the renewable energy access point.

[0069] At the same time, considering that before the commutation failure of the converter station, the new energy access point was fully loaded and all the capacitors in the station were put into operation, when the voltage of the new energy access point increased, the reactive power output of the capacitor 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 invested is at least:

[0070]

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

[0072] The minimum dynamic inductive reactive power demand of the new energy access point in the preset scenario 2 is obtained, which 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 reactive surplus of the system, and the voltage at the new energy access point rises to U 2max(2) ;

[0075] Calculate the voltage U at the point where the new energy is connected 2max(2) Reduce to the maximum permissible 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 of fault recovery, the static capacitive reactive power has no time to exit, and the system reactive power remains, causing transient overvoltage.

[0078] The maximum change in static capacitive reactive power during 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 increment, 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 invested can take 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 put into use 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 They are the calculated values ​​of the minimum dynamic reactive power demand of the PCC point for preset scenario 1 and preset scenario 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 met through simulation), and reduce the dynamic inductive reactive compensation amount by stepwise approximation. See the flowchart for details. Figure 4 The right side figure in .

[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 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 not disconnected 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 bus of the converter station, the new energy unit does not disconnect from the grid and provides 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 2minIt 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 voltage to the minimum voltage U allowed for operation 2Rmin , the short-circuit current that needs to be increased is:

[0095]

[0096] The above formula: U 2Rmin is the minimum allowable voltage at the PCC point, U 2min is the minimum fault voltage at the PCC point; dI 2 The short-circuit current required to raise the PCC 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 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 the economy; S3 specifically includes:

[0102] S31, analyzing the relationship between the transient reactive power output and the steady-state output of the synchronous condenser and the STATCOM in the preset scenario 1 and the preset scenario 2, obtaining the output coefficient, determining the minimum capacity of the synchronous condenser and the STATCOM that meets the capacitive and inductive transient reactive power requirements according to the output coefficient, and selecting the condenser and the STATCOM with the closest capacity in the existing equipment system according to 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 scheme, and determine the final scheme.

[0104] The system diagram of hybrid phase regulator connected to PCC point is as follows Figure 6As 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 T is the system reactance from the phase regulator to the PCC point, 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 phase regulator is in a no-load state before the inverter fails to commutate, that is, E q =U s ≈U 2N , commutation fails, the voltage at the PCC point rises, the current of the phase regulator in equation (15) is negative, absorbing reactive power from the system, and the instantaneous inductive reactive power transmitted to the PCC point is approximately:

[0110]

[0111] The above formula: Q L_SG is the inductive reactive power transmitted from the phase regulator to the PCC point; S SG is the capacity of the phase regulator, k L1 is the inductive reactive power 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 X is the system reactance from the condenser to the PCC point; d is the equivalent reactance of the phase regulator.

[0112] In scenario two, since it is a short-term fault, the phase modulator excitation system has not yet been activated, that is, the fault is restored, and the phase modulator excitation voltage is consistent with scenario one. If the system recovers quickly, the phase modulator 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 modulator excitation system is activated. When the system recovers, it is necessary to coordinate and control the phase modulator excitation system to avoid overvoltage caused by overshoot of the phase modulator. This scenario involves coordinated control of the phase modulator and STATCOM, which is not within the research scope of this invention.) Therefore, in scenario two, the phase modulator can generate more reactive power than scenario one, that is, if it is configured according to the situation of scenario one, it will be able to meet the needs 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; but when the voltage is lower than 0.4 pu or the high voltage is 1.3 pu, it will be disconnected from the grid. The typical UI curve of STATCOM is shown in 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 occurs on the AC side of the converter station. Under the action of the dynamic reactive equipment, the system voltage is stabilized at U 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_SGis 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 emitted 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; k C2 is the capacitive reactive power output coefficient of STATCOM,

[0123] In formula (18) to formula (19), k C1 and k C2 They are the reactive output coefficients of phase regulator and STATCOM during faults.

[0124] Phase regulators and STATCOM need to meet the PCC point's demand for dynamic capacitive reactive power 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 equation (16) and equation (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 equation (18) and equation (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 satisfies 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-shifting scheme: Verify each considered scenario separately. If it cannot meet the requirements, consider increasing the capacity of the phase-shifting or STATCOM. See the flow chart for details. Figure 8 Since the delay of the output 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 configuration technology of a hybrid phase regulator and a STATCOM, which is intended to solve the problem of voltage deterioration or even instability at a large-scale renewable energy access point caused by a sudden rise or drop in the voltage on the AC side of a converter station.

[0132] A hybrid phase-shifting 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 phase-shifting and STATCOM, can utilize the super-strong transient reactive power compensation capability of phase-shifting to quickly restore voltage, and can enable STATCOM to work normally without being disconnected from the grid; in the steady state and fault recovery period, it can utilize the fast reactive power response capability of STATCOM to quickly restore voltage and reduce the mechanical oscillation of the phase-shifting.

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

[0134] The configuration of existing phase-shifting devices or power electronic reactive devices 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 obtains the system's demand for dynamic reactive power through calculation and simulation 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 device accordingly. The configured capacity is closer to the system demand.

[0135] In the prior art, when selecting dynamic reactive power compensation equipment, either phase regulators or power electronic reactive equipment are selected. It is rare to combine the two. Even if the two are combined, they are only considered to be configured 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] Although the transient reactive power of the phase regulator is strong, there are mechanical oscillations. The reactive power response of STATCOM is fast and stable, but the overcurrent capacity is weak. When the voltage is lower than 0.4pu or higher than 1.3pu, it will be disconnected from the grid, which will deteriorate the system voltage. The present invention fully combines the advantages of both, and tries to avoid the voltage being lower than 0.4pu or higher than 1.3pu, thereby avoiding the situation where STATCOM is disconnected from the grid, ensuring that the effect of STATCOM is positive throughout the transient process, assisting the phase regulator to quickly restore the system voltage, and reducing the oscillation of the phase regulator.

[0137] System Example

[0138] According to an embodiment of the present invention, a synchronous condenser and a STATCOM configuration system are 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 used to acquire the minimum dynamic inductive reactive power demand of the new energy access point in the preset scene 1 and the preset scene 2, and take the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in the preset scene 1 and the preset scene 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, configured to configure the condenser and 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 the economy;

[0142] The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and 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 the fault period.

[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, which 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 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, and the computer executable instructions, when executed, implement the steps described in the above method embodiment.

[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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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, obtaining the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2, and taking the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scenario 1 and preset scenario 2 as the minimum dynamic inductive reactive power demand of the new energy access point; S2. Obtaining the minimum dynamic capacitive reactive power of the new energy access point; and S3. 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 the economy, the synchronous condenser and the STATCOM are configured; The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and further causes 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 the fault period.

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, thus causing the voltage on the AC side 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 permissible 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 reactive surplus of the system, and the voltage at the new energy access point rises to U 2max(2) ; Calculate the voltage U at the point where the new energy is connected 2max(2) Reduce to the maximum permissible voltage U 2Rmax The minimum dynamic reactive power S required L2 .

4. The method according to claim 1, characterized in that: 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 occurs on the AC side bus of the converter station 2min ; Calculate the voltage U at the point where the new energy is connected 2mi0 Increase to the minimum dynamic capacitive reactive power S when both the new energy unit and STATCOM are not disconnected 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, characterized in that The S3 specifically includes: S31, analyzing the relationship between the transient reactive power output and the steady-state output of the synchronous condenser and the STATCOM in the preset scenario 1 and the preset scenario 2, obtaining the output coefficient, determining the minimum capacity of the synchronous condenser and the STATCOM that meets the capacitive and inductive transient reactive power requirements according to the output coefficient, and setting the synchronous condenser and the STATCOM configuration scheme according to the minimum capacity of the synchronous condenser and the STATCOM; S32. Use simulation software to verify and adjust the synchronous phase regulator 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 transmitted 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 It is 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 I is the rated voltage of the new energy access point; DT_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 emitted 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 power 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 power 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 checked respectively. 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 used to acquire the minimum dynamic inductive reactive power demand of the new energy access point in preset scene 1 and preset scene 2, and take the maximum value of the minimum dynamic inductive reactive power demand of the new energy access point in preset scene 1 and preset scene 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 new energy access point, the minimum dynamic capacitive reactive power of the new energy access point and the economy; The preset scenario 1 is that due to commutation failure or unipolar blocking, the voltage on the AC side of the converter station rises, and further causes 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 the fault period.

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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