Method and device for calculating withstand voltage of internal gap of converter valve module

Abstract

The invention discloses a method and a device for calculating withstand voltage of an internal gap of a converter valve module. The method comprises the following steps: selecting a representative typical internal gap structure of a converter valve module, which comprises any one of the following items: a small gap between radiators, a small gap between damping capacitors, a small gap between TCU board cards, and a gap between a reactor water inlet / outlet terminal and a copper bar; based on the obtained converter valve module typical internal gap operation impact discharge test data, generating a fitting curve of typical internal gap operation impact 50% discharge voltage and gap distance under the standard weather; determining a function relation between the 50% discharge voltage of the operation impact and the gap distance; determining 50% impact flashover voltage of each typical internal gap as withstand voltage, and generating a function relation between the withstand voltage of each typical internal gap and the gap distance; and determining the real withstand voltage of the typical internal gap of the converter valve module according to the obtained air clear distance of the typical internal gap of the converter valve module. The method is rapid, accurate and practical.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-voltage gap discharge, and particularly relates to a withstand voltage calculation method and device for an internal gap of a converter valve module. BACKGROUND

[0002] Extra-high voltage direct current (HVDC) transmission has become a main means for efficient transmission of large amounts of power due to its large transmission capacity, long transmission distance, small loss, low cost per unit capacity, and saving of land resources for power corridors.

[0003] As a core device of an extra-high voltage direct current transmission project, the stability of a converter valve directly determines whether the project can be stably operated for a long time.

[0004] At present, the design of the internal gap structure of a converter valve module lacks verification and is not targeted, which leads to an overly conservative insulation design of the internal gap of the converter valve module and is not conducive to saving the design cost of the converter valve. Therefore, it is necessary to propose a technical scheme for calculating the withstand voltage of the internal gap of the converter valve module to fill the gap in the insulation design of the internal gap of the converter valve module. SUMMARY

[0005] In view of this, the application provides a withstand voltage calculation method and device for an internal gap of a converter valve module, aiming to solve the problem that there is no withstand voltage calculation method for the internal gap of the converter valve module in the prior art.

[0006] In a first aspect, the application provides a withstand voltage calculation method for an internal gap of a converter valve module, comprising:

[0007] selecting a representative typical internal gap structure of the converter valve module, the typical internal gap structure comprising any one of the following: a small gap between radiators, a small gap between damping capacitors, a small gap between TCU board cards, and a gap between an electric reactor inlet and outlet terminal and a copper bar;

[0008] generating a fitting curve of an operating impulse 50% discharge voltage and a gap distance of the typical internal gap under standard weather based on the obtained operating impulse discharge test data of the typical internal gap of the converter valve module, the gap distance comprising an air clearance of the typical internal gap structure;

[0009] determining a functional relationship between the operating impulse 50% discharge voltage and the gap distance based on the generated fitting curve of the operating impulse 50% discharge voltage and the gap distance of each typical internal gap;

[0010] determining the 50% impulse flashover voltage of each typical internal gap as a withstand voltage, and generating a functional relationship between the withstand voltage and the gap distance of each typical internal gap;

[0011] According to the acquired air clearance of the typical internal gap of the converter valve module, a real withstand voltage of the typical internal gap of the converter valve module is determined.

[0012] Further, it also includes:

[0013] According to the acquired withstand voltage required by different internal gap structures of the converter valve module, an air clearance required by the different internal gap structures of the converter valve module is calculated.

[0014] Further, the function relationship between the operating impulse 50% discharge voltage and the gap distance is determined based on the generated fitting curve of the operating impulse 50% discharge voltage and the gap distance of each typical internal gap, including:

[0015] When the internal gap structure is a small gap between radiators, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0016]

[0017] Wherein, The operating impulse 50% discharge voltage of the small gap between radiators is kV; a1 is the first proportional coefficient, and the value is 0.095; d1 is the small gap between radiators, and the unit is mm; b1 is the first offset coefficient, and the value is 13.265.

[0018] Further, the function relationship between the operating impulse 50% discharge voltage and the gap distance is determined based on the generated fitting curve of the operating impulse 50% discharge voltage and the gap distance of each typical internal gap, including:

[0019] When the internal gap structure is a small gap between damping capacitors, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0020]

[0021] Wherein, The operating impulse 50% discharge voltage of the small gap between damping capacitors is kV; a2 is the second proportional coefficient, and the value is 1.848; d2 is the small gap between damping capacitors, and the unit is mm; b2 is the second offset coefficient, and the value is 10.928.

[0022] Further, the function relationship between the operating impulse 50% discharge voltage and the gap distance is determined based on the generated fitting curve of the operating impulse 50% discharge voltage and the gap distance of each typical internal gap, including:

[0023] When the internal gap structure is a small gap between TCU board cards, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0024]

[0025] wherein, is the TCU board card small gap operating impulse 50% discharge voltage, in kV; a3 is the third proportional coefficient, and the value is 0.815; d3 is the TCU board card small gap, in mm; b3 is the third bias coefficient, and the value is 16.695.

[0026] Further, the generated fitting curve of the typical internal gap operating impulse 50% discharge voltage and the gap distance is used to determine the function relationship between the operating impulse 50% discharge voltage and the gap distance, and the function relationship includes:

[0027] When the internal gap structure is the gap between the reactor inlet and outlet terminal and the copper bar, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0028]

[0029] wherein, is the reactor inlet and outlet terminal and copper bar gap operating impulse 50% discharge voltage, in kV; a4 is the fourth proportional coefficient, and the value is 0.519; d4 is the reactor inlet and outlet terminal and copper bar gap, in mm; b4 is the fourth bias coefficient, and the value is 23.608.

[0030] Further, the 50% impulse flashover voltage of each typical internal gap is determined as the withstand voltage, and the determination includes:

[0031] According to the obtained operating impulse 50% discharge voltage of each typical internal gap structure and the standard deviation θ of the operating impulse scene, the 50% impulse flashover voltage of each typical internal gap is determined as the withstand voltage:

[0032]

[0033] wherein, is the withstand voltage of each typical internal gap, is the operating impulse 50% discharge voltage of each typical internal gap structure, and the value of i includes: 1, 2, 3, and 4.

[0034] In a second aspect, the present application provides a device for calculating the withstand voltage of an internal gap of a converter valve module, and the device includes:

[0035] A typical internal gap selection unit is configured to select a representative typical internal gap structure of the converter valve module, and the typical internal gap structure includes any one of the following: a radiator gap, a damping capacitor gap, a TCU board card gap, and a reactor inlet and outlet terminal and copper bar gap.

[0036] The fitting curve generation unit is configured to generate a fitting curve of the 50% discharge voltage of the typical internal gap under the operation impulse under standard weather conditions and the gap distance, including the air clearance of the typical internal gap structure, based on the obtained 50% discharge voltage of the typical internal gap of the converter valve module under the operation impulse under standard weather conditions.

[0037] The first function relationship determination unit is configured to determine a function relationship between the 50% discharge voltage of the operation impulse and the gap distance based on the generated fitting curve of the 50% discharge voltage of the typical internal gap under the operation impulse and the gap distance.

[0038] The second function relationship determination unit is configured to determine the 50% impulse flashover voltage of each typical internal gap as a withstand voltage, and generate a function relationship between the withstand voltage and the gap distance of each typical internal gap.

[0039] The withstand voltage calculation unit is configured to determine the actual withstand voltage of the typical internal gap of the converter valve module according to the air clearance of the typical internal gap of the converter valve module.

[0040] In a third aspect, the present application provides a terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the method of the first aspect.

[0041] In a fourth aspect, the present application provides a computer storage medium storing computer executable instructions for executing the method of the first aspect.

[0042] Additional aspects and advantages of the present application will be made apparent by the following description of the preferred embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. Furthermore, the same reference numerals are used throughout the several views of the drawings to designate the same or similar parts. In the drawings:

[0044] Figure 1 A flowchart of a withstand voltage calculation method for an internal gap of a converter valve module according to an embodiment of the present application;

[0045] Figure 2 A fitting curve of the 50% discharge voltage U (kV) of a small gap between radiators and the gap distance d (mm) in a withstand voltage calculation method for an internal gap of a converter valve module according to an embodiment of the present application; 50％ ​

[0046] Figure 3 Flowchart of the method for calculating the withstand voltage of the internal gap of the converter valve module according to another embodiment of the application;

[0047] Figure 4 Block diagram of the device for calculating the withstand voltage of the internal gap of the converter valve module according to an embodiment of the application;

[0048] Figure 5 Block diagram of the terminal applying the method for calculating the withstand voltage of the internal gap of the converter valve module according to an embodiment of the application;

[0049] Figure 6 Schematic diagram of the program product applying the method for calculating the withstand voltage of the internal gap of the converter valve module according to an embodiment of the application. DETAILED DESCRIPTION

[0050] Exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. Although exemplary embodiments of the present disclosure are illustrated in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, the embodiments are provided so that the present disclosure can be more thoroughly understood, and the scope of the present disclosure can be accurately conveyed to those skilled in the art. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0051] In recent years, with the continuous improvement of China's DC power transmission equipment level, DC power transmission technology has made a major leap from EHV to UHV. High-voltage and ultra-high-voltage DC power transmission technology has developed and applied rapidly in China.

[0052] The converter valve is the core equipment of the DC power transmission project, and the value of the converter valve accounts for about 22% to 25% of the total price of the complete equipment of the converter station. The design of the converter valve applies the latest technologies and research results of power electronic technology, optical conversion technology, high-voltage technology, control technology and voltage-sharing technology, cooling technology, and high-voltage insulating materials.

[0053] The converter valve is composed of thyristors, damping capacitors, voltage-sharing capacitors, damping resistors, voltage-sharing resistors, saturated reactors, thyristor control units (TCUs) or TCU boards, and soft connection copper bars. Among them, the thyristor is the core component of the converter valve, which determines the current-carrying capacity of the converter valve. By connecting multiple thyristor elements in series, the desired system voltage can be obtained, such as ±800kV / 4750A UHV DC converter valve. The water-cooled radiator required by the thyristor or the reactor (with inlet and outlet water ports) not only dissipates heat for the thyristor, but also acts as a structural member to withstand pressure and needs to be conductive.

[0054] Since there is no insulation design method and standard for the converter valve module at present, the withstand voltage evaluation of the converter valve module can only refer to GB / T 16935.1 Technical Guide for Insulation Coordination of Electrical Equipment in Low Voltage Systems, and the following problems exist: the basic parameters of the electrical gap resistance characteristics given in GB / T 16935.1 are not for typical internal gaps of the converter valve module. A large number of tests show that the margin given by the parameters is large, which is not conducive to the optimization design of the converter valve module; GB / T 16935.1-2008 gives recommended values in the form of a table, and the parameters in the table cannot be calculated according to the standard content in the case of no specification.

[0055] In summary, the current converter valve module design mainly refers to GB / T 16935.1 Technical Guide for Insulation Coordination of Electrical Equipment in Low Voltage Systems, but the insulation design method provided by this standard is not for the converter valve module, resulting in a large insulation design margin of the converter valve and limited applicability.

[0056] The present application provides a technical scheme for calculating the withstand voltage of the internal gap of the converter valve module, including a method and device for calculating the withstand voltage of the internal gap of the converter valve module. The method can give the withstand voltage of the internal gap of the converter valve module under the designed size for different types of typical internal gaps; and the air clearance of each typical internal gap can be calculated according to the designed withstand voltage, which is fast, accurate and practical. In this way, the operation stability of the converter valve can be improved, and reference can be provided for subsequent high-altitude converter valve design.

[0057] As shown in Figure 1 the withstand voltage calculation method of the internal gap of the converter valve module of the embodiment of the present application includes the following steps S100 to S500:

[0058] S100: select a representative typical internal gap structure of the converter valve module, and the typical internal gap structure includes any of the following: small gap between radiators, small gap between damping capacitors, small gap between TCU board cards, gap between water inlet and outlet terminals of the reactor and copper bars;

[0059] S200: based on the obtained operation impulse discharge test data of the typical internal gap of the converter valve module, a fitting curve of the 50% discharge voltage of the typical internal gap under standard weather operation impulse and the gap distance is generated, and the gap distance includes the air clearance of the typical internal gap structure;

[0060] S300: based on the generated fitting curve of the 50% discharge voltage of each typical internal gap under operation impulse and the gap distance, a functional relationship formula of the 50% discharge voltage under operation impulse and the gap distance is determined;

[0061] S400: Determine the 50% impulse flashover voltage of each typical internal gap as the withstand voltage, and generate a function relationship between the withstand voltage of each typical internal gap and the gap distance;

[0062] S500: According to the obtained air clearance of the typical internal gap of the converter valve module, determine the real withstand voltage of the typical internal gap of the converter valve module.

[0063] Further, it also includes: according to the obtained withstand voltage required by the different internal gap structures of the converter valve module, calculating the air clearance required by the different gap structures of the converter valve module.

[0064] Further, the determination of the 50% impulse flashover voltage of each typical internal gap as the withstand voltage includes:

[0065] According to the obtained 50% discharge voltage of the operating impulse of each typical internal gap structure and the standard deviation θ of the operating impulse scene, the 50% impulse flashover voltage of each typical internal gap is determined as the withstand voltage:

[0066]

[0067] Wherein, is the withstand voltage of each typical internal gap, is the 50% discharge voltage of the operating impulse of each typical internal gap structure, and the value of i includes: 1, 2, 3, and 4.

[0068] In some embodiments, the withstand voltage calculation method of the internal gap of the converter valve module of the embodiment of the present application includes:

[0069] Typical internal gaps of the converter valve module are selected, and the typical internal gap structure includes any of the following: small gaps between heat sinks, such as small gaps between thyristor heat sinks, small gaps between damping capacitors, small gaps between TCU board cards, and gaps between water inlet and outlet terminals of reactors and copper bars.

[0070] Specifically, according to the structure characteristics of the converter valve and the electrostatic field simulation results, the typical internal gaps of the converter valve module are extracted, classified, and representative typical internal gaps are selected, which include any of the following: gaps between heat sinks (thyristors), small gaps between damping capacitors, small gaps between TCU board cards, and gaps between water inlet and outlet terminals of reactors and copper bars.

[0071] Further, based on the obtained operating impulse discharge test data of the typical internal gap of the converter valve module, a fitting curve of the 50% discharge voltage U 50％ (kV) and gap distance d (mm) of the typical internal gap under standard weather conditions is generated.

[0072] Specifically, a large number of relevant switching impulse, lightning impulse, DC and power frequency tests are carried out in advance, and the discharge voltages under four voltage types (including switching impulse voltage, lightning impulse voltage, DC voltage and power frequency voltage) are compared, and it is concluded that the switching impulse discharge voltage is the limiting factor of the withstand voltage of the typical internal gap structure of the converter valve module.

[0073] Therefore, based on the above switching valve module typical internal gap switching impulse discharge test data obtained by the test, the fitting curve of the switching valve typical internal gap switching impulse 50% discharge voltage U 50％ (kV) and gap distance d (mm) is generated under standard meteorological conditions.

[0074] Further, based on the generated fitting curve of the switching valve typical internal gap switching impulse 50% discharge voltage U 50％ and gap distance d (mm), the function relationship formula of the corresponding discharge voltage U 50％ (kV) and gap distance d (mm) is determined.

[0075] Specifically, for the ±800kV ultra-high voltage level DC converter valve, by comparing and analyzing the discharge voltages of the four gap types, the function relationship formula of the switching impulse 50% discharge voltage U 50％ and gap distance d (mm) of the four typical internal gaps is given as follows formula (1) to (4).

[0076] When the internal gap structure is the small gap between the heat sinks (thyristor), the function relationship formula of the switching impulse 50% discharge voltage and the gap distance is as follows:

[0077] U 50％ = 0.905 × d + 13.265 (1) or

[0078]

[0079] Among them, is the switching impulse 50% discharge voltage of the small gap between the heat sinks, the unit is kV; a1 is the first proportional coefficient, the value is 0.095; d1 is the small gap between the heat sinks, the unit is mm; b1 is the first offset coefficient, the value is 13.265.

[0080] When the internal gap structure is the small gap between the damping capacitors, the function relationship formula of the switching impulse 50% discharge voltage and the gap distance is as follows:

[0081] U 50％ = 1.848 × d + 10.928 (2) or

[0082]

[0083] Among them, U50% is the 50% discharge voltage of the damping capacitor small gap under the operating impulse, in kV; a2 is the second proportional coefficient, and the value is 1.848; d2 is the damping capacitor small gap, in mm; b2 is the second bias coefficient, and the value is 10.928.

[0084] When the internal gap structure is a TCU board card small gap, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0085] U 50％ = 0.815xd + 16.695 (3) or

[0086]

[0087] Among them, U50% is the 50% discharge voltage of the TCU board card small gap under the operating impulse, in kV; a3 is the third proportional coefficient, and the value is 0.815; d3 is the TCU board card small gap, in mm; b3 is the third bias coefficient, and the value is 16.695.

[0088] When the internal gap structure is a reactor inlet and outlet port terminal and copper bar gap, the function relationship between the operating impulse 50% discharge voltage and the gap distance is as follows:

[0089] U 50％ = 0.519xd + 23.608 (4) or

[0090]

[0091] Among them, U50% is the 50% discharge voltage of the reactor inlet and outlet port terminal and copper bar gap under the operating impulse, in kV; a4 is the fourth proportional coefficient, and the value is 0.519; d4 is the reactor inlet and outlet port terminal and copper bar gap, in mm; b4 is the fourth bias coefficient, and the value is 23.608.

[0092] Further, the 50% impulse flashover voltage of each typical internal gap is determined as the withstand voltage; according to the operating impulse 50% discharge voltage U 50％ of each typical internal gap, the withstand voltage U

[0093] Specifically, the conversion relationship between the operating impulse 50% discharge voltage U 50％ of the gap in engineering and the withstand voltage U s of the gap is given by formula (5) to (6):

[0094]

[0095] Us = U 50％ x (1-3xθ) (6)

[0096] In the above formula, the value of the standard deviation θ of the operating impulse scenario is 0.05.

[0097] Thus, the operating impulse 50% discharge voltage U 50％ (kV) obtained according to the formulas (1) to (4) above can be converted into the withstand voltage U

[0098] Further, the following formulas (7-1) to (10-1) give the withstand voltage U s of the four typical internal gaps inside the converter valve module as a function of the gap distance d (mm); and the formulas (7-2) to (10-2) give the function relationship between the air clearance and the real withstand voltage of the four typical internal gaps inside the converter valve module.

[0099] Specifically, the gap distance or air clearance of the small gap between the heat sinks (thyristors) and the real withstand voltage satisfy the formula (7-1):

[0100] U s = 0.769xd + 11.275 (7-1) or

[0101]

[0102] wherein, U is the real withstand voltage of the small gap between the heat sinks (thyristors); c1 is the first gap coefficient, whose value is 0.769; f1 is the first offset coefficient, whose value is 11.275; and d1 is the preset gap distance of the small gap between the heat sinks (thyristors), which takes a value in the range of 5 mm to 30 mm.

[0103] In addition, the air clearance of the small gap between the heat sinks (thyristors) and the nominal withstand voltage satisfy the formula (7-2):

[0104]

[0105] wherein, U is the nominal withstand voltage of the gap between the heat sinks (thyristors); is the air clearance of the small gap between the heat sinks (thyristors).

[0106] Specifically, the preset gap distance or air clearance d of the small gap between the damping capacitors and the real withstand voltage satisfy the formula (8-1):

[0107] U s= 1.571 x d + 9.289 (8-1) or

[0108]

[0109] wherein, is the real withstand voltage of the small gap between damping capacitors; c2 is the second gap coefficient, whose value is 1.571; f2 is the second offset coefficient, whose value is 9.289; d2 is the preset gap distance of the small gap between damping capacitors, whose value range is 5mm-30mm.

[0110] and the air clearance of the small gap between damping capacitors and its nominal withstand voltage satisfies formula (8-2):

[0111]

[0112] wherein, is the nominal withstand voltage of the small gap between damping capacitors; is the air clearance of the small gap between damping capacitors.

[0113] Specifically, the gap distance or air clearance d of the small gap of TCU board card and the real withstand voltage U s satisfies formula (9-1):

[0114] U s = 0.693 x d + 14.191 (9-1) or

[0115]

[0116] wherein, is the real withstand voltage of the small gap of TCU board card; c3 is the third gap coefficient, whose value is 0.693; f3 is the third offset coefficient, whose value is 14.191; d3 is the preset gap distance of the small gap of TCU board card, whose value range is 10mm-50mm.

[0117] and the air clearance of the small gap of TCU board card and its nominal withstand voltage satisfies formula (9-2):

[0118]

[0119] wherein, is the nominal withstand voltage of the small gap of TCU board card; is the air clearance of the small gap of TCU board card.

[0120] Specifically, the gap distance or air clearance d of the gap between the water inlet and outlet terminals of the reactor and the copper bar and the real withstand voltage U sSatisfying formula (10-1):

[0121] U s =0.441×d+20.067 (10-1) or

[0122]

[0123] in, is the actual withstand voltage of the gap between the inlet and outlet terminals of the reactor and the copper busbar; c4 is the fourth gap coefficient, whose value is 0.441; f4 is the fourth offset coefficient, whose value is 20.067; d4 is the preset gap distance between the inlet and outlet terminals of the reactor and the copper busbar, and its value range is 20mm~120mm.

[0124] Also, the air clearance between the reactor inlet and outlet terminals and the copper busbar and its nominal withstand voltage Satisfying formula (10-2):

[0125]

[0126] in, It is the nominal withstand voltage of the gap between the reactor inlet and outlet terminals and the copper busbar; It is the air clearance between the inlet and outlet terminals of the reactor and the copper busbar.

[0127] Furthermore, based on the obtained air clearance of the typical internal gap of the converter valve module, its actual withstand voltage is determined, and based on the actual withstand voltage and the theoretical withstand voltage, the insulation design margin is calculated.

[0128] Specifically, given the air clearance of a typical internal gap of the converter valve module, its true withstand voltage can be obtained according to equations (7) to (10), thereby determining the insulation design margin of the typical internal gap of the converter valve module.

[0129] Furthermore, the required withstand voltage of the converter valve module gap is determined based on the obtained converter valve module operation impulse withstand voltage and operation impulse distribution coefficient. According to the obtained gap type, calculate the air clearance d required for different gap structures of the converter valve module i .

[0130] Specifically, when designing the internal clearance of the converter valve module, the engineer will provide the required withstand voltage U of the converter valve module clearance. s According to different gap types, the withstand voltage U s Substituting into one of equations (7) to (10), the required air clearance for different gap structures of the converter valve module can be calculated.

[0131] This helps optimize the insulation design of the converter valve module when designing the internal gap of the converter valve module.

[0132] In summary, the method for calculating the withstand voltage of internal gaps in a converter valve module, based on extensive gap discharge tests conducted on these gaps, provides a function curve that plots the withstand voltage of internal gaps in a converter valve module against gap distance. The corresponding functional formula is then derived. Based on this functional formula, the withstand voltage of different gap types within the converter valve module is calculated, and the gap distance and insulation margin are derived. This invention can provide a reference for subsequent converter valve designs, helping to reduce converter valve design costs while ensuring operational reliability.

[0133] In summary, the method for calculating the withstand voltage of the internal gaps of the converter valve module in the embodiment of the present invention is based on the test data of the typical internal gaps of the converter valve module, and determines the method for calculating the withstand voltage of each internal gap of the converter valve module. Compared with the currently used converter valve design standards, the internal gaps of the converter valve module at specific locations (including small gaps between radiators (thyristors), small gaps between damping capacitors, small gaps between TCU boards, and gaps between the inlet and outlet terminals of the reactor and the copper busbar) can be calculated, which is more applicable and more accurate. At the same time, the insulation margin under a given gap distance (or air clearance) can be calculated, providing a reference for the insulation optimization design of the converter valve module.

[0134] In summary, the method for calculating the withstand voltage of the internal gap of the converter valve module in the embodiment of the present invention is based on a large amount of test data, and summarizes the method for calculating the withstand voltage of the typical internal gap of the converter valve module. Through this method, the required air clearance can be calculated using the withstand voltage of a given design, and its actual withstand voltage can also be calculated based on the air clearance of the existing design, and then the insulation margin is given compared with the design standard. Compared with the design basis of the internal gap of the converter valve module currently used, this calculation method is supported by a large amount of test data, provides a more specific calculation formula, and is more targeted. Under the premise of ensuring that the insulation design margin required for engineering operation is met, this calculation method can be used as a reference for the optimization design of the small gap distance in the typical space inside the converter valve module.

[0135] The following describes in detail the method for calculating the withstand voltage of the internal gap of the converter valve module according to the embodiment of the present invention, taking the gap between radiators (thyristors) as an example.

[0136] Step 1: Extract the gap of the converter valve module and select the representative typical internal gap.

[0137] Step 2: Based on the experimental operation shock 50% discharge test data, the following Figure 2 The switching impulse 50% discharge voltage U of the small gap between the heat sinks (thyristors) shown 50％ Fitting curve of (kV) and gap distance d (mm).

[0138] Step three: Based on the operating impulse discharge voltage U 50％ (kV) and gap distance d (mm), the fitting curve is derived to give the operating impulse 50% discharge voltage U 50％ (kV) and gap distance d (mm), as listed in equation (1) ; the operating impulse 50% discharge voltage U 50％ (kV) and gap distance d (mm) is given by equations (2) to (4) in turn.

[0139] Step four: The withstand voltage U s and gap distance d (mm) is given by equation (7).

[0140] The nominal withstand voltage U s of the radiator-to-radiator (thyristor) gap can be calculated by equation (7-1), and the required air clearance of the radiator-to-radiator (thyristor) gap can be calculated by equation (7-2). The function relationship of the withstand voltage U s and gap distance d (mm) of the remaining three typical internal gaps is listed by equations (8-1, 8-2) to (10-1, 10-2) in turn.

[0141] Step five: According to the existing design standard, the operating impulse withstand voltage of the radiator-to-radiator (thyristor) gap in the engineering operation of the ± 800 kV ultra-high voltage level DC converter valve is determined to be 18.58 kV.

[0142] According to equation (7-2), the actual required air clearance of the radiator-to-radiator (thyristor) small gap is calculated to be: i.e. 9.5 mm.

[0143] According to the design air clearance of 22 mm in the existing engineering in operation, according to (7-1), the actual withstand voltage of the current design can be calculated to be:

[0144] i.e. 28.193 kV.

[0145] Compared with the operating impulse withstand voltage of 18.58 kV in the engineering operation, the insulation margin of the existing design can be calculated to be 51.7%, i.e. (28.193-18.58) / 18.58 = 51.7%.

[0146] Naturally, the small gap between the damping capacitor, the small gap between the TCU board card, and the gap between the reactor inlet and outlet terminal and the copper bar can be calculated by equations (8-1, 8-2) to (10-1, 10-2) respectively, and will not be repeated here.

[0147] For example, Figure 3As shown, a method for calculating the withstand voltage of the internal gap of a converter valve module according to another embodiment of the present invention includes the following steps:

[0148] Perform gap extraction on the converter valve module and select representative typical air gaps;

[0149] Based on the test data, a fitting curve of the 50% discharge voltage U° (kV) and the gap distance d (mm) of the typical internal gap operation impulse of the converter valve module was obtained.

[0150] The 50% switching impulse discharge voltage U is derived and calculated. 50％ Functional relationship between (kV) and gap distance d (mm);

[0151] The functional relationship between the switching impulse withstand voltage U (kV) and the gap distance d (mm) is obtained through the calculation formula of the discharge voltage and the withstand voltage.

[0152] Given the withstand voltage Us (kV) required for the project, derive the actual required clearance distance; or

[0153] The insulation margin of the existing design is given based on the actual design clearance distance of the project.

[0154] like Figure 4 As shown, the device for calculating the withstand voltage of the internal gap of the converter valve module according to an embodiment of the present invention includes:

[0155] The typical internal gap selection unit 10 is used to select a typical internal gap structure representative of the converter valve module, wherein the typical internal gap structure includes any one of the following: a small gap between radiators, a small gap between damping capacitors, a small gap between TCU boards, and a gap between the inlet and outlet terminals of the reactor and the copper busbar;

[0156] The fitting curve generating unit 20 is configured to generate a fitting curve of a typical internal gap operation impulse 50% discharge voltage and a gap distance under standard weather conditions based on the acquired typical internal gap operation impulse discharge test data of the converter valve module, wherein the gap distance includes an air clearance of the typical internal gap structure;

[0157] A first functional relationship determination unit 30 is configured to determine a functional relationship between the operating impact 50% discharge voltage and the gap distance based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance for each typical internal gap;

[0158] A second functional relationship determination unit 40 is used to determine a 50% impulse flashover voltage of each typical internal gap as a withstand voltage, and generate a functional relationship between the withstand voltage and the gap distance of each typical internal gap;

[0159] The withstand voltage calculation unit 50 is configured to determine the real withstand voltage of the typical internal gap of the converter valve module according to the obtained air clearance of the typical internal gap of the converter valve module.

[0160] The present application also provides a terminal for performing the method. Please refer to Figure 5 The present application also provides a terminal for performing the method. Please refer to Figure 5 As shown in the figure, the terminal 8 comprises a processor 800, a memory 801, a bus 802 and a communication interface 803, the processor 800, the communication interface 803 and the memory 801 are connected through the bus 802; the memory 801 stores a computer program which can be run on the processor 800, and the processor 800 executes the computer program to perform the method provided by any of the embodiments of the present application.

[0161] The memory 801 can comprise a high-speed random access memory (RAM) and can also comprise a non-volatile memory such as at least one disk memory. The communication connection between the device network element and at least one other network element is realized through at least one communication interface 803 (which can be wired or wireless), and the Internet, a wide area network, a local network, a metropolitan area network, etc. can be used.

[0162] The bus 802 can be an ISA bus, a PCI bus, an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory 801 is used to store a program, and the processor 800 executes the program after receiving an execution instruction, and the method disclosed by any of the embodiments of the present application can be applied to the processor 800 or realized by the processor 800.

[0163] The processor 800 can be an integrated circuit chip with a processing capability of signals. In the implementation process, the steps of the method can be completed by integrated logic circuits or instructions in the form of software in the processor 800. The processor 800 can be a general processor, including a central processing unit (CPU), a network processor (NP), etc.; can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a ready programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware coding processor for execution, or a combination of hardware and software modules in the coding processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register, etc. The storage medium in the art. The storage medium is located in the memory 801, and the processor 800 reads the information in the memory 801, and combines the hardware to complete the steps of the method.

[0164] The terminal provided by the embodiments of the present application is based on the same inventive concept as the method of the embodiments of the present application, and has the same beneficial effects as the method it adopts, runs or implements.

[0165] As shown in Figure 6 The embodiments of the present application also provide a computer readable storage medium corresponding to the method provided by the preceding embodiments, which is an optical disc, and a computer program (i.e. program product 900) is stored on the optical disc. When the computer program is run by a processor, the method provided by any of the preceding embodiments is executed.

[0166] It should be noted that examples of the computer readable storage medium can also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other optical, magnetic storage medium, which will not be described one by one here.

[0167] The computer readable storage medium provided by the embodiments of the present application is based on the same inventive concept as the method of the embodiments of the present application, and has the same beneficial effects as the method it stores and adopts, runs or implements.

[0168] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the application can be practiced otherwise than as specifically described herein.

Claims

1. A method for calculating the withstand voltage of the internal gap of a converter valve module, characterized in that: include: Select a typical internal gap structure representative of the converter valve module, wherein the typical internal gap structure includes any of the following: a small gap between radiators, a small gap between damping capacitors, a small gap between TCU boards, and a gap between the inlet and outlet terminals of the reactor and the copper busbar; Based on the acquired typical internal gap operation impulse discharge test data of the converter valve module, a fitting curve of the typical internal gap operation impulse 50% discharge voltage and the gap distance under standard weather conditions is generated, wherein the gap distance includes the air clearance of the typical internal gap structure; Based on the generated fitting curves of the 50% discharge voltage of the switching impulse and the gap distance of each typical internal gap, a functional relationship between the 50% discharge voltage of the switching impulse and the gap distance is determined; Determine the 50% impulse flashover voltage of each typical internal gap as the withstand voltage, and generate a functional relationship between the withstand voltage and the gap distance of each typical internal gap; The actual withstand voltage of the typical internal gap of the converter valve module is determined based on the obtained air clearance of the typical internal gap of the converter valve module.

2. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: Also includes: Based on the obtained withstand voltage required by different internal gap structures of the converter valve module, the required air clearance of different gap structures of the converter valve module is calculated.

3. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: The function relationship between the operating impact 50% discharge voltage and the gap distance is determined based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance of each typical internal gap, including: When the internal gap structure is a small gap between radiators, the functional relationship between the 50% discharge voltage of the switching impulse and the gap distance is as follows: in, is the 50% discharge voltage of the small gap operation impulse between radiators, in kV; a1 is the first proportional coefficient, its value is 0.095; d1 is the small gap between radiators, in mm; b1 is the first bias coefficient, its value is 13.

265.

4. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: The function relationship between the operating impact 50% discharge voltage and the gap distance is determined based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance of each typical internal gap, including: When the internal gap structure is a small gap between damping capacitors, the functional relationship between the 50% discharge voltage of the switching impulse and the gap distance is as follows: in, is the 50% discharge voltage of the small gap operation impulse between the damping capacitors, in kV; a2 is the second proportional coefficient, its value is 1.848; d2 is the small gap between the damping capacitors, in mm; b2 is the second bias coefficient, its value is 10.

928.

5. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: The function relationship between the operating impact 50% discharge voltage and the gap distance is determined based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance of each typical internal gap, including: When the internal gap structure is a small gap between TCU boards, the functional relationship between the 50% switching shock discharge voltage and the gap distance is as follows: in, is the 50% discharge voltage of the TCU board small gap operation impact, in kV; a3 is the third proportional coefficient, its value is 0.815; d3 is the TCU board small gap, in mm; b3 is the third bias coefficient, its value is 16.

695.

6. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: The function relationship between the operating impact 50% discharge voltage and the gap distance is determined based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance of each typical internal gap, including: When the internal gap structure is the gap between the reactor inlet and outlet terminals and the copper busbar, the functional relationship between the switching impulse 50% discharge voltage and the gap distance is as follows: in, is the 50% operating impulse discharge voltage of the gap between the inlet and outlet terminals of the reactor and the copper busbar, in kV; a4 is the fourth proportional coefficient, whose value is 0.519; d4 is the gap between the inlet and outlet terminals of the reactor and the copper busbar, in mm; b4 is the fourth bias coefficient, whose value is 23.

608.

7. The method for calculating the withstand voltage of the internal gap of the converter valve module according to claim 1, characterized in that: The determination of the 50% impulse flashover voltage of each typical internal gap as the withstand voltage includes: According to the obtained 50% discharge voltage of the switching impulse of each typical internal gap structure and the standard deviation θ of the switching impulse scenario, the 50% impulse flashover voltage of each typical internal gap is determined as the withstand voltage: in, is the typical internal gap withstand voltage, The operating impulse 50% discharge voltage of each typical internal gap structure, the values ​​of i include: 1, 2, 3, 4.

8. A device for calculating the withstand voltage of the internal gap of a converter valve module, characterized in that: include: A typical internal gap selection unit is used to select a typical internal gap structure representative of the converter valve module. The typical internal gap structure includes any of the following: a small gap between radiators, a small gap between damping capacitors, a small gap between TCU boards, and a gap between the inlet and outlet terminals of the reactor and the copper busbar; a fitting curve generating unit, configured to generate a fitting curve of a typical internal gap operation impulse 50% discharge voltage and a gap distance under standard weather conditions based on acquired typical internal gap operation impulse discharge test data of the converter valve module, wherein the gap distance includes an air clearance of the typical internal gap structure; a first functional relationship determination unit, configured to determine a functional relationship between the operating impact 50% discharge voltage and the gap distance based on the generated fitting curves of the operating impact 50% discharge voltage and the gap distance for each typical internal gap; A second functional relationship determination unit is used to determine a 50% impulse flashover voltage of each typical internal gap as a withstand voltage, and generate a functional relationship between the withstand voltage and the gap distance of each typical internal gap; The withstand voltage calculation unit is used to determine the actual withstand voltage of the typical internal gap of the converter valve module based on the obtained air clearance of the typical internal gap of the converter valve module.

9. A terminal comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that Computer-executable instructions are stored, and the computer-executable instructions are used to execute the method according to any one of claims 1 to 7.

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