CN108712058B - Shielding type voltage-sharing circuit - Google Patents
Shielding type voltage-sharing circuit Download PDFInfo
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- CN108712058B CN108712058B CN201710236708.0A CN201710236708A CN108712058B CN 108712058 B CN108712058 B CN 108712058B CN 201710236708 A CN201710236708 A CN 201710236708A CN 108712058 B CN108712058 B CN 108712058B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
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Abstract
The invention provides a shielding type voltage-sharing circuit, which comprises a main circuit and an auxiliary circuit connected with the main circuit in parallel; the main circuit comprises a thyristor level equivalent circuit, a metal terminal earth capacitance and a saturable reactor equivalent circuit; the auxiliary circuit comprises M pi-type circuits which are sequentially connected in series. According to the technical scheme provided by the invention, the potential fixing point of the shielding cover is electrically isolated from the main circuit, only the head end and the tail end of the converter valve are electrically connected with the shielding cover, the leakage effect of stray capacitance to the ground in the converter valve is shielded, the voltage balance distribution of the large-scale series thyristors in a wide frequency domain is realized, the voltage unevenness of the thyristors is lower than 1% under the impact of steep waves, the maximum voltage gradient is reduced to 6.8 kV/mu s, the voltage distortion of key components of the converter valve in the wide frequency domain can be avoided, the reliability and the insulation tolerance of the components are improved, and the high-voltage thyristor has a high engineering application value.
Description
Technical Field
The invention relates to the technical field of extra-high voltage direct current transmission, in particular to a shielding type voltage-sharing circuit.
Background
The converter valve is a core device for realizing electric energy alternating current-direct current conversion, is a heart of direct current engineering and is of great importance for long-term reliable operation. The converter valve has the advantages that metal components in the converter valve are numerous, different in shape and complex in layout, a large amount of stray capacitance exists between the metal components and to the ground, the frequency conversion effect is obvious, and components such as a thyristor, a saturable reactor and the like in the converter valve are in strong nonlinearity. Under the action of 1200 kV/mus steep wave impulse voltage, the stray capacitance of the shielding cover causes unbalanced voltage distribution in the broadband range of hundreds of series thyristors and components thereof in the converter valve, and the unevenness exceeds 40%. In order to solve the problem of balance of series electrical stress of more than one series thyristors and assemblies thereof under the action of impulse voltage, domestic and foreign scholars carry out a great deal of research work and respectively provide own voltage-sharing circuits.
The converter valve of ABB company adopts a voltage-sharing circuit schematic diagram shown in figure 1, wherein Cs(in)And Cg(in)Respectively representing mutual capacitance between metal terminals and metal terminal to ground capacitance, Cs(out)And Cg(out)And respectively representing the mutual capacitance between the shields in the converter valve and the ground capacitance of the shields.
The voltage-sharing circuit shown in fig. 1 adopts a split type shielding method, wherein the shielding cover is divided into a plurality of sections, coupling relations exist among the shielding covers, equivalent capacitance between thyristors of each stage is large, the grounding capacitance of each shielding cover acts on different potential points, the shunting effect is dispersed, and the uneven voltage effect is correspondingly weakened. The saturable reactor in the converter valve is intensively arranged in the middle of the valve component, the impact voltage is not limited by the saturable reactor and directly invades the head end thyristor, and the voltage and the gradient of the thyristor of the stage are improved; for +/-1100 kV direct current engineering with higher voltage level, the level number of the thyristors connected in series with the single valve is increased, the influence of the ground capacitance of the shielding case on the voltage distribution is increased, the voltage and the gradient of the first-level thyristor are increased, the voltage unevenness of the thyristors is increased finally, and the devices are damaged in serious conditions.
Fig. 2 shows a schematic diagram of a voltage-sharing circuit of another conventional converter valve, which adds a longitudinal stray capacitor C on the basis of a split shielding voltage-sharing methodeSo that the ratio of the capacitance to ground to the mutual capacitance is reduced and the non-uniformity of the thyristor is reduced. Along with the increase of the number of layers of the valve module, the leakage effect of the shielding cover to the ground capacitor is enhanced, so that the unevenness of the thyristor is increased.Therefore, the method of increasing the vertical stray capacitance cannot meet the requirement, and a novel voltage-sharing measure is needed.
The original circuit diagram of a voltage-sharing circuit adopted by the Siemens converter valve is shown in figure 3, and the voltage-sharing circuit adopts an integral shielding and component capacitance method for voltage sharing. Wherein the potential of each shielding cover is fixed at the middle potential point of the converter valve module, the voltage of the thyristor in each module is consistent, and the voltage of the thyristor in the upper and lower modules of the single valve has larger unevenness, mainly because the ground capacitance C of the shielding cover in the converter valve in figure 3g(out)And the leakage current of the main circuit to the ground is increased. In order to ensure voltage-sharing distribution of converter valve modules, Siemens company connects component capacitors C in parallel in each converter valve moduletThe component capacitance will take on the voltage of one of the converter valve components, equivalent to voltage sharing by adding a mutual capacitance. The scheme of increasing the component capacitance voltage-sharing can increase the total capacitance value of the single valve, and can increase the switching-on current stress of the thyristor under the non-periodic trigger working condition; and meanwhile, the loss of the converter valve under various operating conditions can be increased.
Disclosure of Invention
In order to overcome the problem of reduced reliability of key components in the converter valve caused by non-uniformity in the implementation scheme of electrical stress balance of the series thyristor and components thereof in the converter valves at home and abroad, the invention provides a shielding type voltage-sharing circuit based on the distribution mechanism of the voltage of the converter valve from the electrical principle of voltage distribution of the series thyristor under impulse voltage, and the invention provides a shielding type voltage-sharing circuit by electrically isolating the potential fixing point of a shielding cover from a main circuit, only electrically connecting the head and the tail end of the converter valve with the shielding cover, shielding the leakage effect of stray capacitance to the ground in the converter valve, finally realizing the voltage balance distribution of the wide-frequency-domain large-scale series thyristor, wherein under the impact of a steep wave, the voltage unevenness of the thyristor is lower than 1 percent, the maximum voltage steepness is reduced to 6.8 kV/mu s, realizing no voltage distortion of the key components of the converter valve under the wide-frequency domain, and improving the reliability and the insulation tolerance of the components, has strong engineering application value.
In order to achieve the purpose of the invention, the invention adopts the following technical scheme:
the invention provides a shielding type voltage-sharing circuit, which comprises a main circuit and an auxiliary circuit connected with the main circuit in parallel;
the main circuit comprises a thyristor level equivalent circuit, a metal terminal ground capacitor and a saturable reactor equivalent circuit;
the auxiliary circuit comprises M pi-shaped circuits which are sequentially connected in series.
The thyristor level equivalent circuits are 2N, wherein the N thyristor level equivalent circuits are sequentially connected in series to form a first thyristor component circuit, and the rest N thyristor level equivalent circuits are sequentially connected in series to form a second thyristor component circuit.
The saturable reactor equivalent circuit comprises a first saturable reactor equivalent circuit, a second saturable reactor equivalent circuit, a third saturable reactor equivalent circuit and a fourth saturable reactor equivalent circuit.
The first saturable reactor equivalent circuit, the first thyristor component circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit, the second thyristor component circuit and the fourth saturable reactor equivalent circuit are sequentially connected in series.
The thyristor-level equivalent circuit comprises a damping resistor RdParasitic inductance LRdDamping capacitor CdThyristor junction capacitor CiAnd mutual capacitance C between the radiatorj；
The damping resistor RdParasitic inductance LRdAnd a damping capacitor CdIn series, form Rd-LRd-CdA branch circuit;
the thyristor junction capacitor CiAnd mutual capacitance C between the radiatorjAre connected in parallel to form Ci//CjA branch circuit;
the R isd-LRd-CdBranch and Ci//CjThe branches are connected in parallel.
The first saturable reactor equivalent circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit and the fourth saturable reactor equivalent circuit respectively comprise mutual capacitors C between the incoming and outgoing linesbCopper loss equivalent electricityResistance RCuHollow inductor LleakMutual capacitance C between wire turn and iron coregrEddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance Csl。
The copper loss equivalent resistance RCuAnd hollow inductor LleakIn series to form RCu-LleakA branch circuit;
the R isCu-LleakMutual capacitance C between branch and wire turn and iron coregrAre connected in parallel to form (R)Cu-Lleak)//CgrA branch circuit;
the eddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance CslAre connected in parallel to form RFe//Lm//CslA branch circuit;
said (R)Cu-Lleak)//CgrBranch and RFe//Lm//CslAfter the branches are connected in series, the mutual capacitance C is between the branches and the inlet and outlet bus barsbAnd (4) connecting in parallel.
The pi-type circuit comprises a shield cover and a ground capacitor Cg1(out)Shield cover to ground capacitance Cg2(out)And a mutual capacitance C between the shielding casessAnd component capacitance Cm。
Mutual capacitance C between the shielding casessAnd component capacitance CmAre connected in parallel to form Cs//CmA branch circuit;
the shield cover has a capacitance to ground Cg1(out)And Cs//CmThe branches are connected in series to form Cg1(out)-(Cs//Cm) Branch line, said Cg1(out)-(Cs//Cm) One end of the branch is grounded, and the other end is connected with a ground capacitor C of the shielding coverg2(out)Of the shield can to ground capacitance Cg2(out)And the other end of the same is grounded.
The metal terminal is equipped with 2N to ground electric capacity, metal terminal is connected between two adjacent thyristor level equivalent circuits to ground electric capacity one end, and its other end ground connection.
Compared with the closest prior art, the technical scheme provided by the invention has the following beneficial effects:
the shielding type voltage-sharing circuit provided by the invention is provided with a main circuit and an auxiliary circuit connected with the main circuit in parallel, wherein the main circuit comprises a thyristor-level equivalent circuit, a metal terminal ground capacitor and a saturable reactor equivalent circuit, and the auxiliary circuit comprises M pi-shaped circuits which are sequentially connected in series, so that the shielding type voltage-sharing of a thyristor in a converter valve is realized;
the head and tail ends of the pi-shaped circuit in the shielding type voltage-sharing circuit are connected with the head and tail ends of the main circuit, and the shielding cover locus is fixed on each stage of capacitor, so that the leakage current flowing into or out of the main circuit to the ground stray capacitor through the shielding cover can be completely blocked;
the main circuit, the shielding cover and the component capacitor are not electrically connected, so that the capacitance current of the shielding cover to the ground is provided by the component capacitor of the auxiliary circuit and does not pass through the main circuit, and key elements of the converter valve are in a complete shielding state, so that the voltage of thyristors in the converter valve is uniformly distributed under high-frequency impact, and the component capacitor is equivalent to an open-circuit state under the low-frequency operation of the converter valve, so that the safe and reliable operation of the main circuit is ensured; under high-frequency impact, the voltage distribution of the component capacitors can be adjusted by using the parameter selection of the capacitors, so that the voltage-equalizing distribution of the component capacitors is ensured;
the invention can reduce the voltage unevenness of the thyristor to 0.17 percent, and the maximum voltage gradient reaches 6.8 kV/mu s; the interlayer voltage unevenness reaches 0.8%, the voltage balance distribution of the series thyristors is realized, and the risk of damage of the thyristors caused by uneven voltage distribution is greatly reduced;
the invention utilizes the parasitic capacitance or the component capacitance to reduce the influence of the stray capacitance on the voltage distribution of the series thyristor in the converter valve, and the ratio of the ground capacitance to the mutual capacitance approaches zero by increasing the mutual capacitance and shielding the leakage effect of the ground capacitance to the main circuit, thereby realizing the voltage balanced distribution of the thyristor.
Drawings
FIG. 1 is a schematic diagram of a prior art ABB company converter valve voltage equalizer circuit;
FIG. 2 is a schematic diagram of a converter valve voltage-sharing circuit in China in the prior art;
FIG. 3 is a schematic diagram of a converter valve voltage-sharing circuit of a Siemens in the prior art;
FIG. 4 is a schematic diagram of a shielded voltage equalizer circuit according to an embodiment of the present invention;
fig. 5 is a structure diagram of a shielded voltage-sharing circuit according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
The zero-distortion and high-reliability shielding voltage-sharing circuit applied to the converter valve provided by the embodiment of the invention mainly adopts two technical schemes of converter valve impulse voltage analysis and capacitance shielding voltage sharing, and the two technical schemes are respectively introduced as follows:
(1) analyzing impulse voltage of the converter valve:
the thyristor in the converter valve adopts a chain type series connection structure, the structure size of the thyristor can be compared with the wavelength of high-frequency impulse voltage, the thyristor cannot be regarded as a centralized parameter circuit, and a distributed parameter mode wave analysis process needs to be established by adopting a transmission line theory. When the converter valve is excited by high-frequency voltage, the saturable reactor serving as an inductance element has larger impedance and cannot suddenly change current, so that no current flows temporarily, namely the inductance is directly opened, and the converter valve can be simplified into a thyristor-level equivalent circuit in a T-shaped capacitance chain network form. The voltage of the connecting point of each stage of thyristor of the converter valve can be obtained according to a circuit transmission equation, and the calculation formula is as follows:
wherein u iskRepresenting the node voltage and the intermediate quantity of the kth level thyristor in the converter valve
CgDenotes the capacitance of the metal terminal to ground, CsRepresenting the mutual capacitance between the metal terminals, then is Cg＜＜CsNamely, b → 0, there are:
from the above formula, it can be seen that the voltage distribution of each node is uniform when the ratio of the capacitance to ground to the mutual capacitance approaches zero.
(2) Capacitive shielding voltage sharing:
the auxiliary loop comprises a plurality of pi-shaped circuits, the head and tail ends of the pi-shaped circuits are connected with the head and tail ends of the main circuit, and the shielding cover electric sites are fixed on the capacitors at all levels, so that the leakage current flowing into or out of the main circuit through the shielding cover to the ground stray capacitor can be completely blocked. The main circuit is not electrically connected with the shielding cover and the component capacitor, and the main circuit is well insulated from the shielding cover and the component capacitor through the insulating slot beam. Therefore, the capacitance current of the shielding cover to the ground is provided by the auxiliary circuit assembly capacitor and does not pass through the main circuit, so that the converter valve key element component is in a complete shielding state, and the voltage of the thyristors in the converter valve is ensured to be uniformly distributed under high-frequency impact. Meanwhile, under the operation of the converter valve in a low-frequency domain, the impedance of the auxiliary circuit is large and is equivalent to an open-circuit state, so that the safe and reliable operation of a main circuit is ensured; under high-frequency impact, the voltage distribution of the component capacitors can be adjusted by using the parameter selection of the capacitors, and the voltage-equalizing distribution of the component capacitors is ensured.
Based on the two technical schemes of converter valve impulse voltage analysis and capacitance shielding voltage sharing, the embodiment of the invention provides a shielding voltage sharing circuit applied to a converter valve, the schematic diagram of the shielding voltage sharing circuit is shown in fig. 4, and C in the schematic diagrams(in)And Cg(in)Respectively representing mutual capacitance between metal terminals and metal terminal to ground capacitance, Cs(out)And Cg(out)Respectively representing mutual capacitance between shielding cases and ground capacitance of the shielding cases in the converter valve, CmAnd showing the parasitic capacitance or component capacitance of components in the converter valve. From FIG. 4, Cg(out)The single-valve main circuit is only connected end to end, and the middle stray capacitor is not electrically connected with the main circuit, so that the voltage distribution of each module of the main circuit is not influenced.
The specific structure of the shielding type voltage-sharing circuit is shown in fig. 5, and the shielding type voltage-sharing circuit comprises a main circuit and an auxiliary circuit connected with the main circuit in parallel; the main circuit and the auxiliary circuit will be described in detail below.
The main circuit comprises a thyristor level equivalent circuit, a saturable reactor equivalent circuit and a metal terminal capacitance to ground;
the number of the thyristor-level equivalent circuits is 2N, wherein the N thyristor-level equivalent circuits are sequentially connected in series to form a first thyristor component circuit, and the rest N thyristor-level equivalent circuits are sequentially connected in series to form a second thyristor component circuit.
The thyristor-level equivalent circuit of the first thyristor component circuit and the second thyristor component circuit comprises a damping resistor RdParasitic inductance LRdDamping capacitor CdThyristor junction capacitor CiAnd mutual capacitance C between the radiatorjThe series-parallel relationship between them is as follows:
wherein the damping resistor RdParasitic inductance LRdAnd a damping capacitor CdIn series, form Rd-LRd-CdA branch circuit; thyristor junction capacitor CiAnd mutual capacitance C between the radiatorjAre connected in parallel to form Ci//CjBranch of the above-mentioned Rd-LRd-CdBranch and Ci//CjThe branches are connected in parallel.
Two radiators are arranged at two ends of the thyristor and the capacitor is formed by a thyristor junction capacitor CiAnd a capacitor C between the two end radiatorsjForming; and the two ends of the thyristor limit the turn-off overshoot voltage of the thyristor through the parallel resistance-capacitance loop.
The saturable reactor equivalent circuit comprises four saturable reactor equivalent circuits, namely a first saturable reactor equivalent circuit, a second saturable reactor equivalent circuit, a third saturable reactor equivalent circuit and a fourth saturable reactor equivalent circuit.
The first saturable reactor equivalent circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit and the fourth saturable reactor equivalent circuit comprise mutual bus bars of the incoming and outgoing linesCapacitor CbCopper loss equivalent resistance RCuHollow inductor LleakMutual capacitance C between wire turn and iron coregrEddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance CslThe series-parallel relationship between them is as follows:
copper loss equivalent resistance RCuAnd hollow inductor LleakIn series to form RCu-LleakBranch of RCu-LleakMutual capacitance C between branch and wire turn and iron coregrAre connected in parallel to form (R)Cu-Lleak)//CgrBranch, eddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance CslAre connected in parallel to form RFe//Lm//CslBranch, (R)Cu-Lleak)//CgrBranch and RFe//Lm//CslAfter the branches are connected in series, the mutual capacitance C is between the branches and the inlet and outlet bus barsbAnd (4) connecting in parallel.
The shielding cover is arranged on the periphery of the first saturable reactor equivalent circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit and the fourth saturable reactor equivalent circuit, so that the mutual capacitance C between the incoming and outgoing bus bars is formedbShielded and therefore negligible.
The series connection sequence among the first saturable reactor equivalent circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit, the fourth saturable reactor equivalent circuit, the first thyristor component circuit and the second thyristor component circuit is as follows:
the first saturable reactor equivalent circuit, the first thyristor component circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit, the second thyristor component circuit and the fourth saturable reactor equivalent circuit are sequentially connected in series.
The number of the metal terminal to ground capacitors is the same as that of the thyristor level equivalent circuits, namely 2N metal terminal to ground capacitors are also arranged, one end of each metal terminal to ground capacitor is connected between every two adjacent thyristor level equivalent circuits, and the other end of each metal terminal to ground capacitor is grounded.
The auxiliary circuit comprises M sequentially connected pi-type circuits, each of which comprises a shield cover and a ground capacitor Cg1(out)Shield cover to ground capacitance Cg2(out)And a mutual capacitance C between the shielding casessAnd component capacitance CmThe series-parallel relationship between them is as follows:
mutual capacitance C between shielding casessAnd component capacitance CmAre connected in parallel to form Cs//CmA branch circuit; shield cover capacitance to ground Cg1(out)And C aboves//CmThe branches are connected in series to form Cg1(out)-(Cs//Cm) Branch of, the Cg1(out)-(Cs//Cm) One end of the branch is grounded, and the other end is connected with a ground capacitor C of the shielding coverg2(out)One end of (1), shield case to ground capacitance Cg2(out)And the other end of the same is grounded.
The voltage distribution of the converter valve adopting the shielding voltage-sharing circuit is shown in table 1, under the condition that the parameter difference of thyristors at all levels is not considered, the voltage distribution trends of the thyristors at all levels are basically consistent, the difference between the maximum value and the minimum value is only 0.004kV, the non-uniformity is 0.17 percent, and the non-uniform coefficient of the converter valve is greatly reduced; the maximum voltage gradient of the thyristor is 6.8 kV/mu s, so that the reliability of the device is greatly improved; voltage distribution among layers of the converter valve is very uniform, and the uneven voltage is 0.03%.
TABLE 1
Compared with the converter valve voltage-sharing technology in the prior art, the converter valve voltage-sharing technology has the following comparison result shown in the table 2, and under the impulse voltage, the maximum voltage gradient, the voltage unevenness and other important indexes of key components of the converter valve, such as the thyristor voltage, the maximum voltage gradient, the voltage unevenness and the like, are obviously superior to the effect of the converter valve electric balancing in the prior art.
TABLE 2
Through the comparison of the above table 2, it can be known that in the working process of the shielded voltage-sharing circuit applied to the converter valve provided by the embodiment of the invention, various important indexes such as the voltage, the maximum voltage gradient, the voltage unevenness and the like of the thyristor of the key component of the converter valve under high-frequency impact are obviously superior to the electric balancing effect of the converter valve in the prior art. The circuit can be popularized and applied to modularized and large-scale series component voltage-sharing equipment, such as CVT (continuously variable transmission), flexible direct-current converter valves, direct-current circuit breakers and other high-voltage equipment, and has wide market application prospect.
Because the embodiment of the invention adopts the impulse voltage analysis technology, the voltage distribution of each component of the main circuit of the converter valve is mainly determined by the stray capacitance to the ground, and the ratio of the capacitance to the ground and the mutual capacitance approaches zero by increasing the mutual capacitance and shielding the leakage effect of the capacitance to the ground on the main circuit, thereby realizing the balanced distribution of the voltage of the thyristor; meanwhile, the technology can simplify the complex circuit of the converter valve and improve the calculation efficiency of the voltage distribution of the thyristor under high-frequency impact;
in addition, the shielding type voltage-sharing circuit provided by the embodiment of the invention can utilize the parasitic capacitance or the component capacitance, reduce the influence of the stray capacitance to the ground on the voltage distribution of the series thyristor in the converter valve, and realize the voltage-sharing distribution of the thyristor;
the shielding voltage-sharing circuit provided by the embodiment of the invention can realize the following three functions: 1) the potential fixed point of the shielding cover is not electrically connected with the main circuit of the converter valve; 2) the potential of the head end and the tail end of the single valve is connected with the potential of the head end and the tail end shielding cover; 3) other potential points of the shielding cover can be fixed on components or capacitor assemblies in the converter valve to be shielded and isolated from the main circuit of the converter valve.
In addition, the embodiment of the invention can also realize that the voltage unevenness of the thyristor is reduced to 0.17 percent, and the maximum voltage gradient reaches 6.8 kV/mu s; the interlayer voltage unevenness reaches 0.8%, the voltage balance distribution of the series thyristors is realized, and the risk of damage of the thyristors caused by uneven voltage distribution is greatly reduced;
the extra-high voltage converter valve enters the overseas market, cross-regional energy interconnection can be realized in the engineering application of regions such as Brazil, Canada and Pakistan in the future, the technology can be possibly applied to the ABB and Siemens converter valves abroad, and meanwhile, the technical scheme can be popularized and applied to voltage-sharing of high-voltage electrical equipment with a component cascade structure, such as CVT (continuously variable transmission), lightning arrester, flexible direct current converter valve and direct current breaker and the like, and has wide market application prospect.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person of ordinary skill in the art can make modifications or equivalents to the specific embodiments of the present invention with reference to the above embodiments, and such modifications or equivalents without departing from the spirit and scope of the present invention are within the scope of the claims of the present invention as set forth in the claims.
Claims (1)
1. A shielding voltage-sharing circuit is characterized by comprising a main circuit and an auxiliary circuit connected with the main circuit in parallel;
the main circuit comprises a thyristor level equivalent circuit, a metal terminal ground capacitor and a saturable reactor equivalent circuit;
the auxiliary circuit comprises M pi-shaped circuits which are sequentially connected in series;
the number of the thyristor-level equivalent circuits is 2N, wherein N thyristor-level equivalent circuits are sequentially connected in series to form a first thyristor component circuit, and the rest N thyristor-level equivalent circuits are sequentially connected in series to form a second thyristor component circuit;
the saturable reactor equivalent circuit comprises a first saturable reactor equivalent circuit, a second saturable reactor equivalent circuit, a third saturable reactor equivalent circuit and a fourth saturable reactor equivalent circuit;
the first saturable reactor equivalent circuit, the first thyristor component circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit, the second thyristor component circuit and the fourth saturable reactor equivalent circuit are sequentially connected in series;
the thyristor-level equivalent circuit comprises a damping resistor RdParasitic inductance LRdDamping capacitor CdThyristor junction capacitor CiAnd mutual capacitance C between the radiatorj；
The damping resistor RdParasitic inductance LRdAnd a damping capacitor CdIn series, form Rd-LRd-CdA branch circuit;
the thyristor junction capacitor CiAnd mutual capacitance C between the radiatorjAre connected in parallel to form Ci//CjA branch circuit;
the R isd-LRd-CdBranch and Ci//CjThe branches are connected in parallel;
the first saturable reactor equivalent circuit, the second saturable reactor equivalent circuit, the third saturable reactor equivalent circuit and the fourth saturable reactor equivalent circuit respectively comprise mutual capacitors C between the incoming and outgoing linesbCopper loss equivalent resistance RCuHollow inductor LleakMutual capacitance C between wire turn and iron coregrEddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance Csl；
The copper loss equivalent resistance RCuAnd hollow inductor LleakIn series to form RCu-LleakA branch circuit;
the R isCu-LleakMutual capacitance C between branch and wire turn and iron coregrAre connected in parallel to form (R)Cu-Lleak)//CgrA branch circuit;
the eddy current loss equivalent resistance RFeNonlinear inductor LmAnd inter-turn capacitance CslAre connected in parallel to form RFe//Lm//CslA branch circuit;
said (R)Cu-Lleak)//CgrBranch and RFe//Lm//CslAfter the branches are connected in series, the mutual capacitance C is between the branches and the inlet and outlet bus barsbParallel connection;
the pi-type circuit comprises a shielding cover and a ground currentContainer Cg1(out)Shield cover to ground capacitance Cg2(out)And a mutual capacitance C between the shielding casessAnd component capacitance Cm；
Mutual capacitance C between the shielding casessAnd component capacitance CmAre connected in parallel to form Cs//CmA branch circuit;
the shield cover has a capacitance to ground Cg1(out)And Cs//CmThe branches are connected in series to form Cg1(out)-(Cs//Cm) Branch line, said Cg1(out)-(Cs//Cm) One end of the branch is grounded, and the other end is connected with a ground capacitor C of the shielding coverg2(out)Of the shield can to ground capacitance Cg2(out)The other end of the first and second electrodes is grounded;
the metal terminal is equipped with 2N to ground electric capacity, metal terminal is connected between two adjacent thyristor level equivalent circuits to ground electric capacity one end, and its other end ground connection.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710236708.0A CN108712058B (en) | 2017-04-12 | 2017-04-12 | Shielding type voltage-sharing circuit |
| PCT/CN2017/085347 WO2018188166A1 (en) | 2017-04-12 | 2017-06-12 | Shielding equalizer circuit |
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| CN201710236708.0A CN108712058B (en) | 2017-04-12 | 2017-04-12 | Shielding type voltage-sharing circuit |
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| CN108712058B true CN108712058B (en) | 2021-10-01 |
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| CN111324971B (en) * | 2020-03-12 | 2023-05-30 | 全球能源互联网研究院有限公司 | Method for optimizing core loss of saturation reactor |
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| CN108712058A (en) | 2018-10-26 |
| WO2018188166A1 (en) | 2018-10-18 |
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