Method, system and equipment for calculating zero-sequence mutual inductance impedance between parallel lines on same tower

Abstract

The invention discloses a method, a system and equipment for calculating zero-sequence mutual inductance impedance between same-tower parallel lines, and the method comprises the steps: carrying out the electrical parameter sampling of a zero-sequence network in non-full-phase operation of a single-circuit line of the same-tower parallel lines, and obtaining the electrical parameter sampling data of the zero-sequence network; acquiring zero-sequence impedance when a full-phase operation loop in the same-tower parallel line exists independently; according to the zero-sequence network electrical parameters and zero-sequence impedance when a full-phase operation loop in the same-tower parallel line exists independently, zero-sequence mutual inductance of the M side of the same-tower parallel line and zero-sequence mutual inductance of the N side of the same-tower parallel line are obtained through calculation; according to the zero-sequence mutual inductance of the M side of the same-tower parallel lines and the zero-sequence mutual inductance of the N side of the same-tower parallel lines, zero-sequence mutual inductance impedance between the same-tower parallel lines is calculated; the circuit does not need to be powered off, the defect that in a traditional testing method, the requirement for the power grid operation mode is high is overcome, the safety risk in the test is reduced, and the calculation result precision is high.

Description

Technical Field

[0001] The invention belongs to the technical field of primary equipment testing of electric power systems, and in particular relates to a method, system and equipment for calculating zero-sequence mutual inductance impedance between parallel-wire lines on the same pole. Background Art

[0002] The accuracy of line sequence impedance parameters is the basis for relay protection setting and short-circuit current calculation. In theory, there is mutual inductance between any two non-vertical transmission lines. The longer the parallel distance, the greater the mutual inductance. As the transmission corridor becomes increasingly tight, more and more lines are installed on the same pole, and the mutual inductance between the lines installed on the same pole becomes greater.

[0003] In the case of parallel lines on the same pole, when a line fails, the current of the faulty line will generate an induced electromotive force on the non-fault line through the line mutual inductance; since the three-phase positive sequence current amplitudes of the faulty line are equal and the phase difference is 120°, the sum of the three induced electromotive forces generated by the three-phase positive sequence current of the faulty line on a certain phase of the non-fault line is zero; similarly, the sum of the induced electromotive forces generated by the three-phase negative sequence current of the faulty line on the non-fault line is also zero; since the three-phase zero sequence current amplitudes of the faulty line are equal and the phases are the same, if the mutual inductance impedance Z of the parallel lines on the same pole is equal, the current amplitudes of the three-phase zero sequence current ... m If the three-phase zero-sequence current of the faulty line generates three induced electromotive forces I0Z on one phase of the non-faulty line, m The amplitudes are equal and the phases are the same. The sum of these three induced electromotive forces is 3I0Z m will be very large; if we set 3I0Z m =I0Z 0m , then 3Z m =Z 0m , then Z 0m It is called line-to-line zero-sequence mutual inductance impedance. For double-circuit or multi-circuit parallel lines, long-distance adjacent lines and other working conditions, the influence of zero-sequence mutual inductance on relay protection in certain modes or states cannot be ignored. Especially in the calculation of asymmetric short circuit or asymmetric phase failure, the influence of zero-sequence mutual inductance must be considered. Therefore, the acquisition of relatively accurate zero-sequence mutual inductance parameters is of great significance for the setting calculation of relay protection and accident analysis of power systems.

[0004] At present, the measurement of zero-sequence mutual inductance impedance of double-circuit or multi-circuit lines mainly includes two methods: line power-off test and line live test. During the power-off test, two or more lines with mutual inductance need to be powered off; and during the live test, the lines to be tested need to be powered off. Both of the above test methods have high requirements on the operation mode of the power grid, and there are safety risks to the test instruments and test personnel during the line parameter test. Summary of the invention

[0005] In view of the technical problems existing in the prior art, the present invention provides a method, system and device for calculating the zero-sequence mutual inductance impedance between lines strung on the same pole, so as to solve the technical problems that the existing zero-sequence mutual inductance impedance testing method has high requirements on the operation mode of the power grid and there are safety risks to the testing instruments and equipment and test personnel during the line parameter testing process.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides a method for calculating zero-sequence mutual inductance impedance between lines in parallel on the same pole, comprising:

[0008] Sampling electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line with parallel lines on the same pole to obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at the protection installation on the M side of the parallel lines on the same pole, and the zero-sequence current at the protection installation on the N side of the parallel lines on the same pole;

[0009] Obtain the zero-sequence impedance when all-phase operating loops exist alone in the same-pole parallel wiring;

[0010] According to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the same-pole parallel line exists alone, the zero-sequence mutual inductance on the M side of the same-pole parallel line and the zero-sequence mutual inductance on the N side of the same-pole parallel line are calculated;

[0011] The zero-sequence mutual inductance impedance between the parallel lines on the same pole is calculated based on the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

[0012] Furthermore, the zero-sequence voltage to ground at both ends of the parallel lines on the same pole includes the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole and the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole; the zero-sequence current at the protection installation on the M side of the parallel lines on the same pole includes the zero-sequence current at the protection installation on the M side of the full-phase operating line and the zero-sequence current at the protection installation on the M side of the non-full-phase operating line; the zero-sequence current at the protection installation on the N side of the parallel lines on the same pole includes the zero-sequence current at the protection installation at N of the full-phase operating line and the zero-sequence current at the protection installation at N of the non-full-phase operating line.

[0013] Furthermore, according to the zero-sequence network electrical parameters and the zero-sequence impedance of the full-phase operating loop when the same-pole parallel lines exist alone, the process of calculating the zero-sequence mutual inductance of the M side of the same-pole parallel lines is as follows:

[0014] The zero-sequence mutual inductance on the M side of the parallel lines on the same pole is calculated based on the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole, the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole, the zero-sequence current at the M-side protection installation of the full-phase operating line, the zero-sequence current at the M-side protection installation of the non-full-phase operating line, and the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole.

[0015] Furthermore, the zero-sequence mutual inductance on the M side of the same-pole parallel line is:

[0016]

[0017] Among them, Z 0M is the zero-sequence mutual inductance on the M side of the parallel lines on the same pole; The zero-sequence voltage to ground of busbar M in parallel on the same pole; It is the zero-sequence voltage to ground of the N busbar in parallel on the same pole; It is the zero sequence current of the full-phase operating line at the protection installation point on the M side; Z is the zero-sequence current at the M-side protection installation of the non-full-phase running line; I0 It is the zero-sequence impedance when all-phase operating loops exist alone in the parallel-pole transmission lines.

[0018] Furthermore, the zero-sequence network electrical parameters and the zero-sequence impedance of the full-phase operating loop when the same-pole parallel line exists alone, the process of calculating the zero-sequence mutual inductance of the N side of the same-pole parallel line is as follows:

[0019] The zero-sequence mutual inductance on the N side of the parallel lines on the same pole is calculated based on the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole, the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole, the zero-sequence current at the protection installation point N of the full-phase operating line, the zero-sequence current at the protection installation point N of the non-full-phase operating line, and the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole.

[0020] Furthermore, the zero-sequence mutual inductance on the N side of the parallel lines on the same pole is:

[0021]

[0022] Among them, Z 0N is the zero-sequence mutual inductance on the N side of the parallel lines on the same pole; The zero-sequence voltage to ground of busbar M in parallel on the same pole; It is the zero-sequence voltage to ground of the N busbar in parallel on the same pole; It is the zero sequence current of the protection installation at N of the full-phase operating line; Z is the zero-sequence current at the protection installation point of the non-full-phase operation line N; I0 It is the zero-sequence impedance when all-phase operating loops exist alone in the parallel-pole transmission lines.

[0023] Furthermore, the zero-sequence mutual inductance impedance between the lines in parallel on the same pole is:

[0024] Z 0m =(Z 0M +Z 0N ) / 2

[0025] Among them, Z0m Z is the zero-sequence mutual inductance impedance between the parallel lines on the same pole; 0M is the zero-sequence mutual inductance on the M side of the parallel line on the same pole; Z 0N It is the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

[0026] Furthermore, grounded neutral points are provided on both sides of the full-phase operation line, and the systems on both sides of the break of the non-full-phase operation line are neutral point grounding systems.

[0027] The present invention also provides a zero-sequence mutual inductance impedance calculation system between parallel lines on the same pole, comprising:

[0028] A parameter sampling module is used to sample electrical parameters of a zero-sequence network of a single-circuit line with parallel lines on the same pole and non-full-phase operation, and obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at the M-side protection installation of the parallel lines on the same pole, and the zero-sequence current at the N-side protection installation of the parallel lines on the same pole;

[0029] A zero-sequence impedance acquisition module is used to obtain the zero-sequence impedance when all-phase operating loops exist alone in the same-pole parallel wiring;

[0030] The first calculation module is used to calculate the zero-sequence mutual inductance on the M side of the parallel-pole line and the zero-sequence mutual inductance on the N side of the parallel-pole line according to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the parallel-pole line exists alone;

[0031] The second calculation module is used to calculate the zero-sequence mutual inductance impedance between the parallel lines on the same pole according to the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

[0032] The present invention also provides a zero-sequence mutual inductance impedance calculation device between parallel lines on the same pole, comprising:

[0033] Memory for storing computer programs;

[0034] A processor is used to implement the steps of the method for calculating the zero-sequence mutual inductance impedance between parallel lines on the same pole when executing the computer program.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a method and system for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole. By sampling electrical parameters of a zero-sequence network of a non-full-phase operation of a single-circuit line of the parallel lines on the same pole, the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at an M-side protection installation of the parallel lines on the same pole, and the zero-sequence current at an N-side protection installation of the parallel lines on the same pole are obtained and used to calculate the zero-sequence mutual inductance impedance between the parallel lines on the same pole. The lines do not need to be powered off, thus avoiding the disadvantage of high requirements on the operation mode of the power grid in traditional test methods, reducing the safety risks in the test, and having high calculation results. The measurement and test errors caused by traditional heterofrequency method tests are avoided. At the same time, the disadvantages of large size, numerous equipment, complex wiring, and the risk of electric shock for test personnel in traditional test equipment are avoided, and the safety risks are greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a zero-sequence network diagram of the parallel double-circuit lines on the same pole in the embodiment when mutual inductance is considered;

[0038] Figure 2 It is a zero-sequence equivalent circuit diagram of the parallel double-circuit lines on the same pole in the embodiment when mutual inductance is considered;

[0039] Figure 3 It is a zero-sequence network diagram of the II circuit line of the parallel double circuit line on the same pole in the embodiment after the single-phase tripping;

[0040] Figure 4 This is a zero-sequence equivalent circuit diagram of the II circuit line of the parallel double-circuit line on the same pole in the embodiment after the single-phase tripping. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail in the following specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] The present invention provides a method for calculating the zero-sequence mutual inductance impedance between lines in parallel on the same pole, comprising the following steps:

[0043] Step 1, sampling electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line of the same-pole parallel line, and obtaining the electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the same-pole parallel line, the zero-sequence current at the M-side protection installation of the same-pole parallel line, and the zero-sequence current at the N-side protection installation of the same-pole parallel line; specifically, the zero-sequence voltage to ground at both ends of the same-pole parallel line includes the zero-sequence voltage to ground of the M busbar of the same-pole parallel line Zero-sequence voltage to ground of N busbar in parallel with the same pole The zero-sequence current of the parallel-pole line at the M-side protection installation includes the zero-sequence current of the full-phase operating line at the M-side protection installation Zero-sequence current at the M-side protection installation of the non-full-phase operating line The zero-sequence current at the N-side protection installation of the parallel-pole line includes the zero-sequence current at the N-side protection installation of the full-phase operating line Zero-sequence current at the protection installation point N of the non-full-phase operation line It should be noted that the zero-sequence network of the non-full-phase operation of a single-circuit line in parallel on the same pole is the zero-sequence network when a single-circuit fault occurs in the same-pole line, causing the single phase to trip; grounded neutral points are set on both sides of the full-phase operation line, and the systems on both sides of the break of the non-full-phase operation line are neutral point grounding systems.

[0044] Step 2: Obtain the zero-sequence impedance Z when all-phase operating loops exist alone in the same-pole parallel line I0 .

[0045] Step 3: Calculate the zero-sequence mutual inductance on the M side of the parallel-pole transmission line and the zero-sequence mutual inductance on the N side of the parallel-pole transmission line according to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the parallel-pole transmission line exists alone.

[0046] Specifically, the process of calculating the zero-sequence mutual inductance on the M side of the parallel lines on the same pole is as follows:

[0047] According to the zero-sequence voltage of busbar M in parallel on the same pole Zero-sequence voltage to ground of N busbar in parallel on the same pole Zero sequence current of full-phase running line at the M-side protection installation Zero sequence current at the M-side protection installation of non-full-phase running line And the zero-sequence impedance Z when the full-phase operating loop exists alone in the parallel line on the same pole I0 , the zero-sequence mutual inductance Z on the M side of the parallel line on the same pole is calculated 0M ; Among them, the zero-sequence mutual inductance Z on the M side of the same pole parallel line 0M for:

[0048]

[0049] Specifically, the process of calculating the zero-sequence mutual inductance on the N side of the parallel lines on the same pole is as follows:

[0050] According to the zero-sequence voltage of busbar M in parallel on the same pole Zero-sequence voltage to ground of N busbar in parallel on the same pole Zero sequence current of the full-phase running line at the protection installation point N Zero sequence current at the protection installation point N of non-full-phase operation line And the zero-sequence impedance Z when the full-phase operating loop exists alone in the parallel line on the same pole I0 , calculate the zero-sequence mutual inductance Z on the N side of the parallel line on the same pole 0N; Wherein, the zero-sequence mutual inductance Z on the N side of the same pole parallel line 0N for:

[0051]

[0052] Step 4: According to the zero-sequence mutual inductance Z on the M side of the parallel line on the same pole 0M And the zero-sequence mutual inductance Z on the N side of the parallel line on the same pole 0N , the zero-sequence mutual inductance impedance Z between the parallel lines on the same pole is calculated 0m ; Wherein, the zero-sequence mutual inductance impedance Z between the parallel lines on the same pole 0m for:

[0053] Z 0m =(Z 0M +Z 0N ) / 2.

[0054] The method for calculating the zero-sequence mutual inductance impedance between parallel lines on the same pole described in the present invention is aimed at the condition that a single-phase switch of a certain line in the parallel lines on the same pole is tripped, and the electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line of the parallel lines on the same pole are used to calculate the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole, and take the average value of the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole, so as to obtain the zero-sequence mutual inductance impedance between the parallel lines on the same pole. During the calculation process, the line does not need to be shut down, which avoids the disadvantage of high requirements on the operation mode of the power grid in the traditional test method, reduces the safety risk in the test, has high calculation accuracy, and avoids the measurement and test errors caused by the traditional different frequency method test, so as to meet the needs of relay protection setting and fault analysis of the double-circuit or multi-circuit lines on the same pole that have been put into operation.

[0055] The present invention also provides a zero-sequence mutual inductance impedance calculation system between parallel lines on the same pole, including a parameter sampling module, a zero-sequence impedance acquisition module, a first calculation module and a second calculation module; the parameter sampling module is used to perform electrical parameter sampling on the zero-sequence network of the single-circuit line of the parallel line on the same pole in non-full-phase operation to obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to the ground at both ends of the parallel line on the same pole, the zero-sequence current at the M-side protection installation of the parallel line on the same pole, and the zero-sequence current at the N-side protection installation of the parallel line on the same pole. A zero-sequence current at the installation location; a zero-sequence impedance acquisition module, used to obtain the zero-sequence impedance when the full-phase operating loop in the same-pole parallel lines exists alone; a first calculation module, used to calculate the zero-sequence mutual inductance on the M side of the same-pole parallel lines and the zero-sequence mutual inductance on the N side of the same-pole parallel lines according to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the same-pole parallel lines exists alone; a second calculation module, used to calculate the zero-sequence mutual inductance impedance between the same-pole parallel lines according to the zero-sequence mutual inductance on the M side of the same-pole parallel lines and the zero-sequence mutual inductance on the N side of the same-pole parallel lines.

[0056] The present invention also provides a zero-sequence mutual inductance impedance calculation device between parallel lines on the same pole, comprising: a memory for storing a computer program; a processor for implementing the steps of a method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole when executing the computer program.

[0057] When the processor executes the computer program, the steps of the above-mentioned method for calculating the zero-sequence mutual inductance impedance between the parallel lines on the same pole are implemented, for example: electrical parameter sampling is performed on the zero-sequence network of the non-full-phase operation of the single-loop line of the parallel line on the same pole to obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network include the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at the protection installation point on the M side of the parallel lines on the same pole, and the zero-sequence current at the protection installation point on the N side of the parallel lines on the same pole; the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole is obtained; according to the electrical parameters of the zero-sequence network and the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole, the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole are calculated; according to the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole, the zero-sequence mutual inductance impedance between the parallel lines on the same pole is calculated.

[0058] Alternatively, the processor implements the functions of each module in the above system when executing the computer program, for example: a parameter sampling module, which is used to sample the electrical parameters of the zero-sequence network of the non-full-phase operation of the single-loop line of the same-pole parallel line to obtain the electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the same-pole parallel line, the zero-sequence current at the M-side protection installation of the same-pole parallel line, and the zero-sequence current at the N-side protection installation of the same-pole parallel line; a zero-sequence impedance acquisition module, which is used to obtain the zero-sequence impedance when the full-phase operating loop exists alone in the same-pole parallel line; a first calculation module, which is used to calculate the zero-sequence mutual inductance on the M side of the same-pole parallel line and the zero-sequence mutual inductance on the N side of the same-pole parallel line according to the electrical parameters of the zero-sequence network and the zero-sequence impedance when the full-phase operating loop exists alone in the same-pole parallel line; a second calculation module, which is used to calculate the zero-sequence mutual inductance impedance between the same-pole parallel lines according to the zero-sequence mutual inductance on the M side of the same-pole parallel line and the zero-sequence mutual inductance on the N side of the same-pole parallel line.

[0059] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing functions, and the instruction segments are used to describe the execution process of the computer program in the zero-sequence mutual inductance impedance calculation device between the same-pole parallel lines.

[0060] For example, the computer program can be divided into a parameter sampling module, a zero-sequence impedance acquisition module, a first calculation module and a second calculation module, and the specific functions of each module are as follows: the parameter sampling module is used to sample the electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line of the same-pole parallel line to obtain the electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to the ground at both ends of the same-pole parallel line, the zero-sequence current at the M-side protection installation of the same-pole parallel line, and the zero-sequence current at the N-side protection installation of the same-pole parallel line. zero-sequence current; the zero-sequence impedance acquisition module is used to obtain the zero-sequence impedance when the full-phase operating loop in the same-pole parallel lines exists alone; the first calculation module is used to calculate the zero-sequence mutual inductance on the M side of the same-pole parallel lines and the zero-sequence mutual inductance on the N side of the same-pole parallel lines according to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the same-pole parallel lines exists alone; the second calculation module is used to calculate the zero-sequence mutual inductance impedance between the same-pole parallel lines according to the zero-sequence mutual inductance on the M side of the same-pole parallel lines and the zero-sequence mutual inductance on the N side of the same-pole parallel lines.

[0061] The zero-sequence mutual inductance impedance calculation device between the parallel lines on the same pole can be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The zero-sequence mutual inductance impedance calculation device between the parallel lines on the same pole may include, but is not limited to, a processor and a memory. Those skilled in the art can understand that the above is an example of a zero-sequence mutual inductance impedance calculation device between the parallel lines on the same pole, and does not constitute a limitation on the zero-sequence mutual inductance impedance calculation device between the parallel lines on the same pole, and may include more components than the above, or a combination of certain components, or different components. For example, the zero-sequence mutual inductance impedance calculation device between the parallel lines on the same pole may also include input and output devices, network access devices, buses, etc.

[0062] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The processor is the control center of the zero-sequence mutual inductance impedance calculation device between the same-pole parallel lines, and uses various interfaces and lines to connect various parts of the zero-sequence mutual inductance impedance calculation device between the same-pole parallel lines.

[0063] The memory can be used to store the computer program and / or module, and the processor implements various functions of the zero-sequence mutual inductance impedance calculation device between the same-pole parallel lines by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0064] The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (SmartMediaCard, SMC), a secure digital (SecureDigital, SD) card, a flash card (FlashCard), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0065] Example

[0066] In this embodiment, a calculation process of the zero-sequence mutual inductance impedance between parallel double-circuit lines on the same pole is taken as an example to provide a method for calculating the zero-sequence mutual inductance impedance between parallel double-circuit lines on the same pole, including the following steps:

[0067] Step 1. When the single-phase switch of a single-circuit line with parallel lines on the same pole is tripped, a zero-sequence network of the non-full-phase operation of the single-circuit line with parallel lines on the same pole is obtained; specifically, a single-phase switch tripping fault is preset on the II circuit line of the parallel double-circuit line on the same pole to obtain a zero-sequence network of the non-full-phase operation of the single-circuit line with parallel lines on the same pole; and the I circuit line of the parallel double-circuit line on the same pole is a full-phase operation line.

[0068] Step 2: Sampling electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line in parallel on the same pole to obtain the electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground of the M busbar in parallel on the same pole Zero-sequence voltage to ground of N busbar in parallel on the same pole Zero sequence current of full-phase running line at the M-side protection installation Zero sequence current at the M-side protection installation of non-full-phase running line Zero sequence current of the full-phase running line at the protection installation point N And the zero sequence current at the protection installation point N of the non-full-phase operation line

[0069] Step 3: Obtain the zero-sequence impedance Z when all-phase operating loops exist alone in the same-pole parallel line I0 .

[0070] Step 4: Based on the zero-sequence voltage to ground of busbar M in parallel on the same pole Zero-sequence voltage to ground of N busbar in parallel on the same pole Zero sequence current of full-phase running line at the M-side protection installation Zero sequence current at the M-side protection installation of non-full-phase running line And the zero-sequence impedance Z when the full-phase operating loop exists alone in the parallel line on the same pole I0 , the zero-sequence mutual inductance Z on the M side of the parallel line on the same pole is calculated 0M ; Among them, the zero-sequence mutual inductance Z on the M side of the same pole parallel line 0M for:

[0071]

[0072] Step 5: Based on the zero-sequence voltage to ground of busbar M in parallel on the same pole Zero-sequence voltage to ground of N busbar in parallel on the same pole Zero sequence current of the full-phase running line at the protection installation point N Zero sequence current at the protection installation point N of non-full-phase operation line And the zero-sequence impedance Z when the full-phase operating loop exists alone in the parallel line on the same pole I0 , calculate the zero-sequence mutual inductance Z on the N side of the parallel line on the same pole 0N ; Wherein, the zero-sequence mutual inductance Z on the N side of the same pole parallel line 0N for:

[0073]

[0074] Step 6: The zero-sequence mutual inductance Z of the M side of the parallel line on the same pole 0M And the zero-sequence mutual inductance Z on the N side of the parallel line on the same pole 0N Take the average value as the zero-sequence mutual inductance impedance Z between the lines in parallel on the same pole 0m ; Wherein, the zero-sequence mutual inductance impedance Z between the parallel lines on the same pole 0m for:

[0075] Z 0m =(Z 0M +Z 0N ) / 2

[0076] Among them, Z 0m Z is the zero-sequence mutual inductance impedance between the parallel lines on the same pole; 0M is the zero-sequence mutual inductance on the M side of the parallel line on the same pole; Z 0N It is the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

[0077] Calculation principle:

[0078] For parallel double-circuit lines on the same pole, when there is zero-sequence current on the same pole, for one of the lines, the zero-sequence current of the other line will have a magnetic effect on it, that is, the zero-sequence impedance between the parallel double-circuit lines on the same pole must take into account the influence of the mutual inductance impedance of the other line.

[0079] As attached Figure 1 As shown in the figure, assuming that in the parallel double-circuit lines on the same pole, the zero-sequence impedance of the I-circuit line when it exists alone is Z I0 , the zero-sequence impedance when the II circuit exists alone is Z II0 The zero-sequence mutual inductance impedance of the parallel double-circuit line on the same pole, that is, the zero-sequence mutual inductance impedance between the parallel lines on the same pole is Z 0m , then the voltage equation is:

[0080]

[0081]

[0082] in, is the zero-sequence voltage at the two breaks; Z is the zero-sequence current of the full-phase operation line at the protection installation on the M side, that is, the zero-sequence current of the I loop at the protection installation on the M side; I0 It is the zero-sequence impedance when the I-loop line exists alone; Z is the zero-sequence current at the M-side protection installation of the non-full-phase operation line, that is, the zero-sequence current of the II loop at the M-side protection installation; 0m Z is the zero-sequence mutual inductance impedance between the parallel lines on the same pole; II0 It is the zero-sequence impedance when the II circuit exists alone.

[0083] Rewriting the above voltage equation, we get:

[0084]

[0085]

[0086] Therefore, according to the above voltage equation, we can get the zero-sequence equivalent circuit of the parallel double-circuit line considering mutual inductance, as shown in the attached figure. Figure 2 shown.

[0087] As attached Figure 3 As shown, attached Figure 3 The zero-sequence network diagram of the parallel double-circuit line on the same pole after the single-phase tripping of the II circuit line is given in the figure; among them, the I circuit line is a full-phase operation line. is the zero-sequence voltage at the two break ports; when the fault phase circuit breakers on both sides of the II circuit trip, the two phase-break ports are not in full-phase operation; when the distributed capacitance of the line is ignored, the two phase-break ports can be combined into one phase-break port, that is

[0088] Therefore, the zero-sequence voltage to ground of busbar M in parallel on the same pole is for:

[0089]

[0090] Zero-sequence voltage to ground of N busbar in parallel on the same pole for:

[0091]

[0092] in, It is the zero-sequence current of the full-phase operation line at the protection installation at N, that is, the zero-sequence current of the I loop at the protection installation at the N side; It is the zero-sequence current at the protection installation at N of the non-full-phase operation line, that is, the zero-sequence current at the protection installation at the N side of the II loop; the requirement is that the positive direction of the zero-sequence current is stipulated to flow from the bus to the protected line, and the zero-sequence voltage of the M bus and the N bus to the ground shall not use the line PT zero-sequence voltage; when the capacitance to the ground is ignored, there is: but:

[0093]

[0094] At this time, the zero-sequence mutual inductance Z on the M side of the parallel line on the same pole 0M for:

[0095]

[0096] The zero-sequence mutual inductance Z on the N side of the parallel line on the same pole is 0N for:

[0097]

[0098] It should be noted that zero-sequence current is generated only when both sides of the break are neutral-grounded systems, that is, both sides of the break of the non-full-phase running line are neutral-grounded systems; at this time, the magnitude of the zero-sequence current is equal to the phase difference of the equivalent electromotive force on both sides. It is related to the phase angle δ between the equal electromotive forces on both sides; specifically, when δ=0°, the negative-sequence current and the zero-sequence current are zero, that is, the no-load condition; when δ=180°, the negative-sequence current and the zero-sequence current have their maximum values.

[0099] In this embodiment, based on the zero-sequence network of a single-phase tripping fault inside one of the parallel double-circuit lines, when calculating the zero-sequence mutual inductance between the double-circuit lines, the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole are calculated respectively by sampling the zero-sequence voltage of the two buses, the zero-sequence current flowing through the two lines, and the zero-sequence impedance when the line mutual inductance is not considered; secondly, since the influence of the distributed capacitance of the line is not taken into account, in order to ensure the calculation accuracy, the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole are averaged and used as the zero-sequence mutual inductance impedance of the parallel double-circuit lines, that is, the zero-sequence mutual inductance impedance between the parallel lines on the same pole is obtained; the zero-sequence mutual inductance is calculated by using the electrical quantity during the non-full-phase operation of the line, which avoids the measurement risk during power outage measurement and also avoids the measurement and experimental errors caused by the heterofrequency method test.

[0100] It should be noted that since circuit breakers of voltage levels of 330kV and above are all phase-splitting switches, when a single-phase grounding fault occurs, the circuit breakers of the faulty phases on both sides will trip; during the period when the reclosing switch is not actuated, the non-full-phase operation line is a non-full-phase operation of the two broken phases; during the non-full-phase operation, negative-sequence current and zero-sequence current will appear at the break; and the reclosing time of a general 330kV circuit breaker is about 600ms, and the relevant electrical parameters can reach a steady state within the time period from the fault removal to the reclosing switch action; therefore, the electrical quantities during the period when the fault phases on both sides of the line are disconnected can be used to calculate the zero-sequence mutual inductance; in addition, during the duration of the fault, the zero-sequence current caused by the grounding fault will also flow in the adjacent full-phase operation lines; among them, there must be a grounded neutral point on both sides of the full-phase operation line; the zero-sequence current in the full-phase operation line meets the measurement accuracy requirements of the mutual inductor, so the calculation method described in this embodiment is also applicable to the calculation of the zero-sequence mutual inductance between parallel lines adjacent to the non-full-phase operation lines during the fault period.

[0101] For the description of the relevant parts of the zero-sequence mutual inductance impedance calculation system and device between parallel lines on the same pole provided in this embodiment, reference can be made to the detailed description of the corresponding parts of the zero-sequence mutual inductance impedance calculation method between parallel lines on the same pole described in this embodiment, which will not be repeated here.

[0102] In the present invention, the zero-sequence mutual inductance impedance is calculated by utilizing the electrical parameters of one of the double-circuit or multi-circuit lines on the same pole after the single-phase tripping. This avoids the disadvantages of large size, numerous equipment, complicated wiring, and risk of electric shock for test personnel in traditional test equipment, and greatly reduces the safety risk. A theoretical calculation method is used to obtain the zero-sequence mutual inductance parameters between parallel lines without the need for power outages. This avoids the disadvantage of high requirements on the operation mode of the power grid in traditional test methods and reduces the safety risk in the test. Secondly, theoretical calculations are performed by obtaining the zero-sequence voltage and current of the lines at both ends. The calculation method has high accuracy and avoids the measurement and test errors caused by traditional heterofrequency testing.

[0103] The method for calculating the zero-sequence mutual inductance impedance of lines in parallel on the same pole described in the present invention can achieve the acquisition of the zero-sequence mutual inductance impedance between double-circuit lines on the same pole without power outage, so as to meet the needs of relay protection setting and fault analysis of the double-circuit or multi-circuit lines in parallel on the same pole that have been put into operation. The calculation result has high accuracy and does not require on-site testing. At the same time, it can avoid test risks such as electric shock to personnel and test errors in a single test method, and the safety and convenience performance in main network application is greatly improved.

[0104] The above embodiment is only one of the implementation methods that can realize the technical solution of the present invention. The scope of protection claimed by the present invention is not limited only to this embodiment, but also includes changes, replacements and other implementation methods that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention.

Claims

1. A method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole, characterized in that: include: Sampling electrical parameters of the zero-sequence network of the non-full-phase operation of the single-circuit line with parallel lines on the same pole to obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at the protection installation on the M side of the parallel lines on the same pole, and the zero-sequence current at the protection installation on the N side of the parallel lines on the same pole; Obtain the zero-sequence impedance when all-phase operating loops exist alone in the same-pole parallel wiring; According to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the same-pole parallel line exists alone, the zero-sequence mutual inductance on the M side of the same-pole parallel line and the zero-sequence mutual inductance on the N side of the same-pole parallel line are calculated; The zero-sequence mutual inductance impedance between the parallel lines on the same pole is calculated based on the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

2. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 1, characterized in that: The zero-sequence voltage to ground at both ends of the parallel lines on the same pole includes the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole and the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole; the zero-sequence current at the protection installation on the M side of the parallel lines on the same pole includes the zero-sequence current at the protection installation on the M side of the full-phase operating line and the zero-sequence current at the protection installation on the M side of the non-full-phase operating line; the zero-sequence current at the protection installation on the N side of the parallel lines on the same pole includes the zero-sequence current at the protection installation at N of the full-phase operating line and the zero-sequence current at the protection installation at N of the non-full-phase operating line.

3. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 2, characterized in that: According to the zero-sequence network electrical parameters and the zero-sequence impedance of the full-phase operating loop when the same-pole parallel lines exist alone, the process of calculating the zero-sequence mutual inductance on the M side of the same-pole parallel lines is as follows: The zero-sequence mutual inductance on the M side of the parallel lines on the same pole is calculated based on the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole, the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole, the zero-sequence current at the M-side protection installation of the full-phase operating line, the zero-sequence current at the M-side protection installation of the non-full-phase operating line, and the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole.

4. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 3, characterized in that: The zero-sequence mutual inductance on the M side of the same-pole parallel line is: Among them, Z 0M is the zero-sequence mutual inductance on the M side of the parallel lines on the same pole; The zero-sequence voltage to ground of busbar M in parallel on the same pole; It is the zero-sequence voltage to ground of the N busbar in parallel on the same pole; It is the zero sequence current of the full-phase operating line at the protection installation point on the M side; Z is the zero-sequence current at the M-side protection installation of the non-full-phase running line; I0 It is the zero-sequence impedance when all-phase operating loops exist alone in the parallel-pole transmission lines.

5. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 2, characterized in that: The zero-sequence network electrical parameters and the zero-sequence impedance of the full-phase operating loop when the same-pole parallel line exists alone, and the process of calculating the zero-sequence mutual inductance on the N side of the same-pole parallel line are as follows: The zero-sequence mutual inductance on the N side of the parallel lines on the same pole is calculated based on the zero-sequence voltage to ground of the M busbar of the parallel lines on the same pole, the zero-sequence voltage to ground of the N busbar of the parallel lines on the same pole, the zero-sequence current at the protection installation point N of the full-phase operating line, the zero-sequence current at the protection installation point N of the non-full-phase operating line, and the zero-sequence impedance when the full-phase operating loop exists alone in the parallel lines on the same pole.

6. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 5, characterized in that: The zero-sequence mutual inductance on the N side of the parallel lines on the same pole is: Among them, Z 0N is the zero-sequence mutual inductance on the N side of the parallel lines on the same pole; The zero-sequence voltage to ground of busbar M in parallel on the same pole; It is the zero-sequence voltage to ground of the N busbar in parallel on the same pole; It is the zero sequence current of the protection installation at N of the full-phase operating line; Z is the zero-sequence current at the protection installation point of the non-full-phase operation line N; I0 It is the zero-sequence impedance when all-phase operating loops exist alone in the parallel-pole transmission lines.

7. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 1, characterized in that: The zero-sequence mutual inductance impedance between the parallel lines on the same pole is: WITH 0m =(From 0M +Z 0N ) / 2 Among them, Z 0m Z is the zero-sequence mutual inductance impedance between the parallel lines on the same pole; 0M is the zero-sequence mutual inductance on the M side of the parallel line on the same pole; Z 0N It is the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

8. The method for calculating zero-sequence mutual inductance impedance between parallel lines on the same pole according to claim 1, characterized in that: Grounded neutral points are provided on both sides of the full-phase operation line, and both sides of the break of the non-full-phase operation line are neutral point grounding systems.

9. A zero-sequence mutual inductance impedance calculation system between parallel lines on the same pole, characterized in that: include: A parameter sampling module is used to sample electrical parameters of a zero-sequence network of a single-circuit line with parallel lines on the same pole and non-full-phase operation, and obtain electrical parameter sampling data of the zero-sequence network; wherein the electrical parameter sampling data of the zero-sequence network includes the zero-sequence voltage to ground at both ends of the parallel lines on the same pole, the zero-sequence current at the M-side protection installation of the parallel lines on the same pole, and the zero-sequence current at the N-side protection installation of the parallel lines on the same pole; A zero-sequence impedance acquisition module is used to obtain the zero-sequence impedance when all-phase operating loops exist alone in the same-pole parallel wiring; The first calculation module is used to calculate the zero-sequence mutual inductance on the M side of the parallel-pole line and the zero-sequence mutual inductance on the N side of the parallel-pole line according to the zero-sequence network electrical parameters and the zero-sequence impedance when the full-phase operating loop in the parallel-pole line exists alone; The second calculation module is used to calculate the zero-sequence mutual inductance impedance between the parallel lines on the same pole according to the zero-sequence mutual inductance on the M side of the parallel lines on the same pole and the zero-sequence mutual inductance on the N side of the parallel lines on the same pole.

10. A zero-sequence mutual inductance impedance calculation device between parallel lines on the same pole, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the method for calculating the zero-sequence mutual inductance impedance between parallel-connected lines on the same pole as described in any one of claims 1 to 8 when executing the computer program.

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