CN112684290B - Efficient calculation method for interelectrode short-circuit fault current of flexible direct-current power grid - Google Patents
Efficient calculation method for interelectrode short-circuit fault current of flexible direct-current power grid Download PDFInfo
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Abstract
The invention relates to a high-efficiency calculation method for interelectrode short-circuit fault current of a flexible direct-current power grid, which comprises the steps of firstly establishing a universal equivalent model of the flexible direct-current power grid under the interelectrode short-circuit fault according to the limited contribution of a converter station far away from a fault point to the fault current; secondly, a state equation set for describing the fault equivalent model is formed, and the state equation set is directly formed by power grid parameters without complex correction; and finally, solving the state equation set by adopting a Taylor series expansion method of the matrix exponential function, and obtaining the fault current. The method has the advantages that the equation set is easy to form, the fault current solving efficiency is high, and the method has extremely high accuracy in the capacitor discharging stage after the fault. The method has strong reference significance for quick evaluation of fault current of the flexible direct-current power grid and setting of key parameters of equipment such as a direct-current breaker and a current limiter.
Description
The invention belongs to the technical field of power transmission and distribution, and particularly relates to an efficient calculation method for interelectrode short-circuit fault current of a flexible direct-current power grid.
Background
The flexible direct-current power grid can be applied to large-scale integrated sending of new energy power generation, flexible distribution of active power at a power receiving end is achieved, controllability of a power system is improved, and the flexible direct-current power grid has a good application prospect. However, because a Modular Multilevel Converter (MMC) lacks a rotating element, energy on the direct current side of a flexible direct current power grid directly comes from stored energy in a submodule capacitor of the MMC, the direct current power grid is a system with low inertia and weak damping, huge direct current fault current can be generated within milliseconds after short-circuit fault on the direct current side, and particularly, the safe and stable operation of the system is seriously threatened by extremely-large short-circuit fault. The direct current circuit breaker can effectively break a fault line, and current limiting equipment such as a fault current limiter can reduce the fault current level of the system. The calculation of the short-circuit fault current between the poles of the flexible direct-current power grid has important significance on the aspects of parameter design of a direct-current circuit breaker and current limiting equipment, element parameter optimization of the direct-current power grid and the like.
The existing method for calculating the fault current of the flexible direct-current power grid is mainly used for establishing a fault model of the direct-current power grid on the basis of an RLC equivalent branch of a converter station and an RL model of a direct-current line and solving the fault current through an equation set of a time domain or a complex frequency domain. There are also methods to reflect the ac feed-in current source in parallel across the equivalent capacitance of the converter station in an effort to improve the accuracy of the calculation. The equations in these methods are required to describe the whole dc network, and complicated correction processes are involved, or complicated network analysis methods such as the accompanying branch method are used to perform analysis. In conclusion, the methods generally face the problem that the system of equations is difficult to form and solve, and the problem is particularly prominent under the condition that the direct current network is large in scale, so that the solution efficiency of the fault current is greatly reduced. In addition, none of the existing methods can better accommodate the change in the failure point.
Along with the expansion of the scale of the flexible direct-current power grid, in order to adapt to engineering requirements, establish a simplified flexible direct-current power grid fault model and provide an accurate and efficient direct-current short-circuit fault current calculation method, the method is an important problem to be solved urgently.
Disclosure of Invention
The invention provides an efficient calculation method for an interelectrode short-circuit fault current of a flexible direct-current power grid, and a flow chart of the method is shown in figure 1. The method firstly establishes a universal equivalent model of the flexible direct-current power grid under the condition of the interelectrode short-circuit fault, and is shown in figure 2. The specific steps of the method need to be explained by combining a flexible direct-current power grid fault equivalent model, which is as follows:
step (1), after the inter-electrode short circuit fault occurs, the converter Station directly connected with the fault point is called a Main Station (MS), the converter Station directly connected with the Main Station is called a Neighbor Station (NS), the current of the direct current outgoing line of the neighbor Station, which is not directed to the Main Station, is considered as a constant and is aggregated as I out 。
And (2) establishing a flexible direct-current power grid fault equivalent model on the basis of the RLC equivalent branch of the converter station and the RL model of the direct-current line. As shown in fig. 2, the transition resistance R f And I of NS out Will be flexible togetherThe direct current power grid is divided into a left side and a right side, and before a direct current fault occurs, active power is transmitted from the left side to the right side. The master station on the left is called MS A The master station on the right side is called MS B And MS A The n (n ≧ 0) contiguous neighbors are denoted NS 1 ,NS 2 ,…,NS n And MS B The m (m ≧ 0) contiguous neighbors are denoted NS R1 ,NS R2 ,…,NS Rm 。MS A The voltage of the equivalent capacitor is denoted as u a (t),MS B The voltage of the equivalent capacitor is denoted as u b (t), the current of the left positive fault line is recorded as i a (t), the current of the right positive fault line is recorded as i b (t) of (d). The line current from each adjacent station to the main station of the left line is respectively recorded as i 1 (t)，i 2 (t),……，i n (t), the voltage of the equivalent capacitance of each adjacent station on the left side is denoted as u 1 (t)，u 2 (t),……，u n (t)。R 1a And L 1a Is adjacent 1 station (NS) 1 ) And MS A Direct lumped RL parameters including positive and negative lines and DC reactors between two stations, R ja ，L ja And R na ，L na The meaning is similar. The parameters on the right have the same meaning as on the left, except with the subscript "R".
Note that when a failure occurs inside the three-port ring network, the neighboring station (denoted as NS) Δ ) Is not only related to MS A The connected adjacent stations are also connected with the MS B The connected neighboring stations. Need to connect NS Δ NS equivalent to the left side 1 And NS on the right side R1 Two separate converter stations as shown in fig. 3.
Wherein, the parameter relationship before and after the equivalence is as follows:
original NS Δ I of (A) outΔ Is allocated as NS 1 I of (A) out1 And NS R1 I of (A) outR1 As shown in formula (2):
in the formula (2), i 2p And i 1p Are respectively i 2 (t) and i 1 (t) the value immediately before the fault. Such an equivalent method follows the law of conservation of energy, as well as the kirchhoff current law for converter station nodes.
And (3) considering the current of the positive line and the voltage of the equivalent capacitor of the converter station as state variables. For each one containing a single converter station and a transition resistance R f The KVL equation is established for all loops, a KCL equation is established for each converter station node, and a preliminary state equation set is obtained, wherein the equation set is shown in a formula (3).
In equation (1), vector i is the line current vector, equal to [ i a (t),i 1 (t),…,i n (t),i b (t),i R1 (t),…,i Rm (t)] T The vector u is the voltage vector of the equivalent capacitance of the converter station, equal to u a (t),u 1 (t),…,u n (t),u b (t),u R1 (t),…,u Rm (t)] T . Vector quantity
And
is the inverse of the voltage current vector with respect to time. Vector U S And I S Due to the I of NS out The generation, which can be expressed as:
and
in the formula (3), the matrix RLC is a resistance parameter matrix, an inductance parameter matrix, and a capacitance parameter matrix, which are respectively expressed as:
in the formula (4), L is multiplied by L -1 The system of equations becomes:
the system of equations can ultimately be expressed in simplified form as follows:
equation (10) is the final system of state equations, vector x is the state vector, x = [ i, u ])] T (ii) a Vector quantity
Is the derivative of the state variable with respect to time t; matrix a is a coefficient matrix; the vector b is I out Generated constant excitation vector, b = [ L = -1 U S ,I S ] T 。
And (4) solving the equation (10) by adopting a Taylor series expansion method of the matrix exponential function, and obtaining the fault current. The solution to the system of state equations is:
in formula (11), x 0 Is the initial value of the state variable, i.e. the value of the state variable at the moment before the fault, x 0 ＝[i ap ,i 1p ,i bp ,i R1p ,u ap ,u 1p ,u R1p ] T ,e At And e A(t-τ) The matrix is an exponential function, and can be solved by a Taylor series expansion method, as shown in formula (12).
When a low-resistance fault occurs, the Taylor expansion order is taken to be the 3 rd order or the 4 th order, and good fault current calculation accuracy can be achieved. With transition resistance R f The required taylor expansion order increases accordingly. For example, when the fault resistance reaches 50 Ω, the expansion order needs to be 5 th or 6 th, and when the fault resistance reaches 100 Ω, the expansion order needs to be 7 th or 8 th.
The technical effect obtained by adopting the technical scheme of the invention is as follows:
compared with the simulation based on PSCAD/EMTDC, the method can efficiently and accurately solve the fault current of the interpolar short-circuit fault of the flexible direct-current power grid, the relative error between the calculated value of the fault current and the simulated value is always kept within +/-3% within 7ms after the fault, and the time range is enough to deal with the setting of the key parameters of the direct-current circuit breaker.
Compared with the prior art, the invention has the beneficial effects that:
(1) Because the simplified flexible direct-current power grid fault equivalent model is provided, the order of the equation set is greatly reduced, the solving speed is greatly improved, and less memory is occupied.
(2) The equation set is formed efficiently, the steps are simple, and a complex correction process is not needed.
(3) The system can effectively cope with a large-scale direct-current power grid and can flexibly adapt to the change of fault points.
Drawings
Fig. 1 is a flow chart of an efficient calculation method of an inter-pole short-circuit fault current of a flexible direct-current power grid.
Fig. 2 is a general equivalent model of a flexible direct-current power grid under an inter-electrode short-circuit fault.
FIG. 3 is a schematic diagram of an equivalent method of neighboring stations in a three-terminal ring network (a); (b) Neighbor station NS Δ Equivalent to NS 1 And NS R1 。
FIG. 4 is a topological diagram of a seven-terminal true bipolar flexible direct current power grid testing system.
Detailed Description
To further illustrate the embodiments of the present invention, the following describes an example of an efficient calculation method for an inter-pole short-circuit fault current of a flexible dc power grid according to the present invention. It should be emphasized that the following description is merely exemplary in nature and is in no way intended to limit the scope of the invention or its applications.
Fig. 4 is a topological diagram of a seven-terminal true bipolar flexible direct current power grid testing system, and parameters of a converter station are shown in table I.
TABLE I testing parameters of a single MMC in a converter station of a system
With f 3 For example, the point generating inter-electrode short circuit fault, the Cb-A4 station is MS A The Cb-A7 station is MS B The Cb-A2 station being NS 1 The Cb-A3 station being NS 2 The Cb-A5 station being NS R1 . The current of a positive line pointing to a fault point of the Cb-A4 station is i a (t) the Cb-A7 station has a positive line current i pointing to the fault point b (t) of (d). The positive line current of the Cb-A2 station pointing to the Cb-A4 station is i 1 (t) the positive line current directed from the Cb-A3 station to the Cb-A4 station is i 2 (t) the positive line current directed from the Cb-A5 station to the Cb-A7 station is i R1 (t) of (d). The sum of the currents of the Cb-A2 station pointing to the Cb-A1 station and the Cb-A3 station is I out1 And remains unchanged after the fault. The sum of the currents of the Cb-A3 station directed to the Cb-A2 station and the Cb-A5 station is I out2 And remains unchanged after the fault. Cb-A5 station fingerThe sum of the currents to the Cb-A3 station and the Cb-A6 station is I outR1 And remains unchanged after the fault.
Filling the parameters of the corresponding converter station and the line parameters into the formula (4) -formula (8) to form a state equation set, and obtaining the fault current after solving.
Table II shows the calculated fault current and the simulated value of the fault current at the time 7ms after the fault when the short-circuit fault between poles with different transition resistances occurs at each fault point shown in fig. 4, and the taylor series expansion order used in parentheses is shown.
Table II relative error (%) of calculated fault current and simulated value at 7ms post-fault for each fault point
As can be seen from the above table, the fault current calculation method of the present invention has a relatively high calculation accuracy.
It should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (2)
1. A method for efficiently calculating interelectrode short-circuit fault current of a flexible direct-current power grid is characterized by comprising the following steps:
constructing a simplified equivalent model of the interpolar short-circuit fault of the flexible direct-current power grid;
setting state variables according to a simplified equivalent model of the interpolar short-circuit fault of the flexible direct-current power grid, and constructing a state equation set;
solving a state equation set by using a Taylor series expansion method of the matrix exponential function to obtain a current value of the fault line;
the method for constructing the simplified equivalent model of the interpolar short-circuit fault of the flexible direct-current power grid comprises the following steps:
each converter station adopts an RLC series equivalent branch, and a DC overhead line adopts an RL model;
after the inter-electrode short-circuit fault occurs, the converter station connected with the fault point is called a main station, the converter station connected with the main station is called an adjacent station, and the current on the direct current outgoing line of the adjacent station which is not directed to the main station is considered to keep the value before the fault unchanged and is aggregated to be a constant I out ；
Transition resistance R f And adjacent station I out The flexible direct-current power grid is divided into a left side and a right side together, and before a direct-current fault occurs, the left side transmits active power to the right side;
the master station on the left is called MS A The master station on the right is called MS B And MS A The n (n ≧ 0) contiguous neighbors are denoted NS 1 ，NS 2 ，…，NS n And MS B The m (m ≧ 0) contiguous neighbors are denoted NS R1 ，NS R2 ，…，NS Rm ；
Using R in the model 1a 、L 1a To represent neighbor 1 station (NS) 1 ) And MS A Lumped RL parameters including positive and negative circuits and DC reactors between two stations;
the method for establishing the state equation set by setting the state variables according to the simplified equivalent model of the interpolar short-circuit fault of the flexible direct-current power grid comprises the following steps: the voltage of the equivalent capacitor of the converter station and the current on the direct current line are considered as state variables;
MS A the voltage of the equivalent capacitor is denoted u a (t)，MS B The voltage of the equivalent capacitor is denoted as u b (t), the current of the left positive fault line is recorded as i a (t), the current of the right positive fault line is recorded as i b (t), the line current from each adjacent station to the main station of the left line is respectively recorded as i 1 (t)，i 2 (t)，……，i n (t), the voltage of the equivalent capacitance of each adjacent station on the left side is denoted as u 1 (t)，u 2 (t)，……，u n (t), the parameters on the right have the same meaning as on the left, except with the subscript "R";
for each oneOne comprising a single converter station and a transition resistor R f The KVL equation is established for all loops, a KCL equation is established for each converter station node, and a preliminary state equation set is obtained as shown in the following formula:
where the vector i is the line current vector, equal to [ i ] a (t)，i 1 (t)，…，i n (t)，i b (t)，i R1 (t)，…，i Rm (t)] T The vector u is the voltage vector of the equivalent capacitance of the converter station, equal to u a (t)，u 1 (t)，…，u n (t)，u b (t)，u R1 (t)，…，u Rm (t)] T Vector of motion
And
is the inverse of the voltage current vector with respect to time, vector U S And I S Due to the I of NS out Generation, which can be expressed as:
U S ＝[0,R s1 I out1 ,R s2 I out2 ,…,R sn I outn ,…,0,R sR1 I outR1 ,R sR2 I outR2 ,…,R sRm I outRm ] T
the matrixes R, L, C in the preliminary state equation set are respectively a resistance parameter matrix, an inductance parameter matrix and a capacitance parameter matrix, which are respectively expressed as:
left-hand multiplying L in a preliminary set of state equations -1 The system of equations becomes:
recapitulation is as follows in simplified form:
this equation is the final set of state equations, vector x is the state vector, x = [ i, u ])] T Vector of
The derivative of the state variable with respect to time t, matrix A being a matrix of coefficients and vector b being I out Generated constant excitation vector, b = [ L = -1 U S ，I S ] T ；
Solving a state equation set by using a Taylor series expansion method of a matrix exponential function, wherein the step of obtaining the current value of the fault line comprises the following steps:
the solution to the final set of state equations can be expressed as:
in the formula, x 0 Is the initial value of the state variable, i.e. the value of each state variable at the moment before the fault, x 0 ＝[i ap ，i 1p ，…，i np ，i bp ，i R1p ，…，i Rmp ，u ap ，u 1p ，…，u np ，u bp ，u R1p ，…，u Rmp ] T ，e At And e A(t-τ) Is a matrix exponential function, and is solved by a Taylor series expansion method, as shown in the following formula:
when the low-resistance fault occurs, the Taylor expansion order is taken to be 3 rd order or 4 th order along with the transition resistance R f The required taylor expansion order increases accordingly.
2. The method for efficiently calculating the interelectrode short-circuit fault current of the flexible direct-current power grid according to claim 1, wherein the model further comprises processing of a three-terminal ring network:
when the fault occurs in the three-terminal ring network, NS Δ Is not only with MS A The connected adjacent stations are connected with the MS B Connected neighbor stations, requiring NS Δ NS equivalent to the left side 1 And NS on the right side R1 Two independent converter stations which are not directly connected any more have parameter relations before and after equivalence as follows:
original NS Δ I of (A) outΔ Is allocated as NS 1 I of (A) out1 And NS R1 I of (A) outR1 Of the formula
In the formula i 2p And i 1p Are respectively i 2 (t) and i 1 (t) the value immediately before the fault, the equivalent method follows the law of conservation of energy, and kirchhoff's current law for the converter station nodes.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015197137A1 (en) * | 2014-06-27 | 2015-12-30 | Siemens Aktiengesellschaft | Transient protection for multi-terminal hvdc grid |
| CN106018924A (en) * | 2016-06-22 | 2016-10-12 | 华北电力大学 | Direct-current power grid bipolar short-circuit fault current calculation method |
| CN106918759A (en) * | 2017-03-16 | 2017-07-04 | 许继集团有限公司 | A kind of MMC direct-current short circuits fault detection method and device |
| CN108258660A (en) * | 2016-12-29 | 2018-07-06 | 中国电力科学研究院 | A kind of processing method of flexible direct current power grid DC side failure |
| CN108923396A (en) * | 2018-07-04 | 2018-11-30 | 山东大学 | A kind of short circuit current quick calculation method of multiterminal flexible direct current power grid |
| CN108933445A (en) * | 2018-06-28 | 2018-12-04 | 东北电力大学 | DC grid short-circuit current calculation method based on the loop method of analysis |
| CN110108921A (en) * | 2019-05-27 | 2019-08-09 | 山东大学 | Consider that the flexible direct current Short-circuit Current of Power Network of converter Control calculates method and system |
| CN110108986A (en) * | 2019-05-29 | 2019-08-09 | 华北电力大学 | DC grid fault current complex frequency domain calculation method |
| CN110161369A (en) * | 2019-04-11 | 2019-08-23 | 华北电力大学 | A kind of bipolar short trouble localization method of DC grid based on overhead transmission line RL model |
| CN110350515A (en) * | 2019-06-20 | 2019-10-18 | 西安交通大学 | A kind of flexible direct current power network modeling method suitable for analysis of the fault current |
| CN111211574A (en) * | 2020-01-10 | 2020-05-29 | 北京交通大学 | Method for calculating bipolar fault current on direct current side of multi-terminal direct current power grid based on half-bridge type MMC |
| CN111245002A (en) * | 2020-03-02 | 2020-06-05 | 武汉大学 | MMC-based double-pole flexible direct-current power grid short-circuit and ground fault current prediction method |
| CN111327068A (en) * | 2020-04-07 | 2020-06-23 | 浙江大学 | Direct-current side fault voltage calculation method of MMC type direct-current power grid with pseudo-bipolar structure |
| CN111856322A (en) * | 2020-05-09 | 2020-10-30 | 上海交通大学 | Direct-current distribution network bipolar short-circuit fault accurate positioning method and device based on MMC |
-
2020
- 2020-12-16 CN CN202011479977.8A patent/CN112684290B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015197137A1 (en) * | 2014-06-27 | 2015-12-30 | Siemens Aktiengesellschaft | Transient protection for multi-terminal hvdc grid |
| CN106018924A (en) * | 2016-06-22 | 2016-10-12 | 华北电力大学 | Direct-current power grid bipolar short-circuit fault current calculation method |
| CN108258660A (en) * | 2016-12-29 | 2018-07-06 | 中国电力科学研究院 | A kind of processing method of flexible direct current power grid DC side failure |
| CN106918759A (en) * | 2017-03-16 | 2017-07-04 | 许继集团有限公司 | A kind of MMC direct-current short circuits fault detection method and device |
| CN108933445A (en) * | 2018-06-28 | 2018-12-04 | 东北电力大学 | DC grid short-circuit current calculation method based on the loop method of analysis |
| CN108923396A (en) * | 2018-07-04 | 2018-11-30 | 山东大学 | A kind of short circuit current quick calculation method of multiterminal flexible direct current power grid |
| CN110161369A (en) * | 2019-04-11 | 2019-08-23 | 华北电力大学 | A kind of bipolar short trouble localization method of DC grid based on overhead transmission line RL model |
| CN110108921A (en) * | 2019-05-27 | 2019-08-09 | 山东大学 | Consider that the flexible direct current Short-circuit Current of Power Network of converter Control calculates method and system |
| CN110108986A (en) * | 2019-05-29 | 2019-08-09 | 华北电力大学 | DC grid fault current complex frequency domain calculation method |
| CN110350515A (en) * | 2019-06-20 | 2019-10-18 | 西安交通大学 | A kind of flexible direct current power network modeling method suitable for analysis of the fault current |
| CN111211574A (en) * | 2020-01-10 | 2020-05-29 | 北京交通大学 | Method for calculating bipolar fault current on direct current side of multi-terminal direct current power grid based on half-bridge type MMC |
| CN111245002A (en) * | 2020-03-02 | 2020-06-05 | 武汉大学 | MMC-based double-pole flexible direct-current power grid short-circuit and ground fault current prediction method |
| CN111327068A (en) * | 2020-04-07 | 2020-06-23 | 浙江大学 | Direct-current side fault voltage calculation method of MMC type direct-current power grid with pseudo-bipolar structure |
| CN111856322A (en) * | 2020-05-09 | 2020-10-30 | 上海交通大学 | Direct-current distribution network bipolar short-circuit fault accurate positioning method and device based on MMC |
Non-Patent Citations (1)
| Title |
|---|
| 考虑频变参数和直流控制的直流输电系统线路故障解析;徐敏等;《电力系统自动化》;20150610;第39卷(第11期);37-44 * |
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