CN107741536A - Line no-load charging vector inspection method - Google Patents

Abstract

The invention is applicable to the technical field of relay protection of high-voltage transmission lines, and provides a line no-load charging vector inspection method, setting L substations, M substations and N substations, and determining the no-load charging of single-circuit lines by changing the connection mode between substations. The line protection and circuit breaker protection vectors when the line is charged at the break of the substation, the double-circuit line is charged at no-load, and the line is charged with high resistance to no-load; the wiring mode of the substation is 3/2 wiring mode; L and N substations Both include a complete string, M substation includes two complete strings, and three circuit breakers are set on a complete string; L and M substations are connected through line I, and M and N substations are connected through line II, and line I and line Both ends of II are equipped with shunt reactors that can control switching. The above method for checking the vector of no-load charging on the line can integrate the charging types that may occur during the no-load charging process into a simulation system, and quickly and accurately complete the vector checking.

Description

Line no-load charging vector inspection method

technical field

The invention belongs to the field of relay protection of high-voltage transmission lines, and in particular relates to a method for checking a no-load charging vector of a line.

Background technique

Vector inspection is the main item in relay protection work. Vector inspection is mainly to check the correctness of current transformer ratio selection and polarity, and the correctness of voltage and current secondary circuit wiring. Vector check error will lead to malfunction or refusal of relay protection in normal operation state or fault state. Therefore, the correctness of the vector must be strictly guaranteed before the relay protection is officially put into operation.

When the 500kV EHV new line and the 1000kV UHV new line of 3/2 connection are put into operation, no-load charging vector inspection is required. In the process of implementing the present invention, the inventor found that during the no-load vector inspection, the inspectors draw the main wiring diagram of the system to analyze the voltage and current angles every time, and then compare with the actual vector inspection results on site, so that the verification process Takes too long and cannot be sure the veracity of the check result.

Contents of the invention

In view of this, the embodiment of the present invention provides a method for checking the line no-load charging vector to solve the problem in the prior art that the vector verification process takes too long and the correctness of the verification result cannot be determined.

An embodiment of the present invention provides a method for checking the no-load charging vector of a line, including: setting an L substation, an M substation, and an N substation; wherein, the wiring mode of the L substation, M substation, and N substation is a 3/2 wiring mode; The L substation is connected to the M substation through a line I, and the M substation is connected to the N substation through a line II, and both ends of the line I and the line II are provided with shunt reactors that can control switching;

By changing the connection mode between L substation, M substation and N substation, determine the no-load charging of single-circuit lines, no-load charging of lines in substation breaches, no-load charging of double-circuit lines and lines with high resistance to no-load charging Vector of protection and circuit breaker protection.

Optionally, the L substation includes one complete string, the M substation includes two complete strings, and the N substation includes one complete string; the line I is respectively connected to the L substation and the M substation, and the II line is respectively connected to the M substation and the N substation; three sequentially connected circuit breakers are set on the one complete string.

Optionally, the determination of the line protection and circuit breaker protection vectors during no-load charging of the single circuit line by changing the connection mode between the L substation, the M substation and the N substation specifically includes:

The L substation is connected to the M substation through the line I, the M substation includes a complete string, and the shunt reactor is cut off in the line I;

The substation L charges the substation M, and determines the line protection vector of the L side of the I line according to the charging situation; where, the L side line of the I line is represented as the L side line of the line I;

Determine the size of the empty charging current on the L side of the I line according to the length of the line I;

According to the polarity of the CT coil protected by the circuit breaker, the vector of the circuit breaker protection of the L substation is determined.

Optionally, the vector of line protection and circuit breaker protection when the line is charged at the break of the substation by changing the connection mode between the L substation, the M substation and the N substation is determined, specifically including:

The L substation is connected to the M substation through the line I, and the M substation is connected to the N substation through the line II. The M substation includes a first complete string and a second complete string, and the first complete string of the M substation It is connected to the line I, the second complete string of the M substation is connected to the line II, the shunt reactor is cut off in the line I, and the shunt reactor is cut off in the line II;

Substation L is charging for substation M, and the vector of line protection on the L side of line I is determined according to the charging situation; the size of the empty charging current on the L side of line I is determined according to the total length of line I and line II; according to the CT coil protected by the circuit breaker in substation L The polarity of the L substation determines the protection vector of the circuit breaker;

M substation is charging for N substation, according to the charging situation, determine the protection vector of I-line M-side line, and determine the size of empty charging current on I-line M-side according to the length of line II; according to the circuit breaker protection in the first complete string of M substation The polarity of the CT coils, determining the vector for circuit breaker protection in the first complete string of substation M;

M substation is charging for N substation, according to the charging situation, determine the vector of line protection on M side of line II, and determine the size of empty charging current on M side of line II according to the length of line II; according to the circuit breaker protection in the second complete string of substation M The polarity of the CT coils, determines the vector for circuit breaker protection in the second complete string of substation M.

Optionally, the determination of the line protection and circuit breaker protection vectors during no-load charging of the double-circuit line by changing the connection mode between the L substation, the M substation and the N substation specifically includes:

The L substation is connected to the M substation through the line I, and the M substation is connected to the N substation through the line II; the N substation is set on the L substation, and the M substation includes the first complete string and the second complete string The first complete string of the M substation is connected to the line I, the second complete string of the M substation is connected to the line II, the shunt reactor is cut off in the line I, and the shunt reactor is cut off in the line II;

L substation is charging for M substation, and the vector of line protection on the L side of line I is determined according to the charging situation; the size of the empty charging current on the L side of line I is determined according to the total length of line I and line II; according to the CT of the circuit breaker protection in the L substation The polarity of the coil, which determines the vector of the circuit breaker protection of the L substation;

Substation M charges substation L, determines the line protection vector of I-line M side according to the charging situation, and determines the empty charging current of I-line M side according to the length of line II; according to the circuit breaker protection in the first complete string of M substation The polarity of the CT coils, determining the vector for circuit breaker protection in the first complete string of substation M;

Substation M charges for substation L, determines the line protection vector of line II on the M side according to the charging situation, and determines the empty charging current on the M side of line II according to the length of line II; according to the circuit breaker protection in the second complete string of substation M The polarity of the CT coils, determines the vector for circuit breaker protection in the second complete string of substation M.

Optionally, the determination of the line protection and circuit breaker protection vectors when the line is charged with high resistance to no-load by changing the connection mode between the L substation, the M substation and the N substation specifically includes:

The L substation is connected to the M substation by line I, the M substation is connected to the N substation by line II, the M substation involves a first complete string and a second complete string, the first complete string of the M substation Connected to the line I, the second complete string of the M substation is connected to the line II, a shunt reactor is put into the line I, and a shunt reactor is put into the line II;

Substation L is charged for substation M, and the vector of line protection on the L side of line I is determined according to the charging situation; the empty charging on the L side of line I is determined according to the total length of line I and line II and the capacity of the shunt reactors put into line I and line II The size of the flow; according to the polarity of the CT coil of the circuit breaker protection in the L substation, determine the vector of the circuit breaker protection of the L substation;

The M substation charges the N substation, and determines the line protection vector of the M side of the I line according to the charging situation, and determines the empty charging current of the M side of the I line according to the length of the line II and the capacity of the shunt reactor put into the line II; according to the M substation The polarity of the CT coil protected by the circuit breaker in the first complete string of M substation determines the vector of the circuit breaker protection in the first complete string of M substation;

The M substation charges the N substation, and determines the line protection vector of the M side of the II line according to the charging situation, and determines the empty charging current of the M side of the II line according to the length of the line II and the capacity of the shunt reactor put into the line II; according to the M substation The polarities of the CT coils protected by the circuit breakers in the second complete string of the M substation determine the vectors protected by the circuit breakers in the second complete string of the substation M.

Compared with the prior art, the embodiment of the present invention has the following beneficial effects: the embodiment of the present invention determines the no-load charging of the single-circuit line by setting the L substation, the M substation and the N substation and changing the connection mode between the three substations. The vectors of line protection and circuit breaker protection for substation breach no-load charging, double-circuit line no-load charging and line with high resistance no-load charging; among them, the wiring mode of the substation is 3/2 wiring mode, and the L and N substations Both include a complete string, M substation includes two complete strings, and three circuit breakers are set on a complete string; L and M substations are connected through line I, and M and N substations are connected through line II, and line I and line Both ends of the II are equipped with shunt reactors that can be switched on and off; by changing the connection mode of the substation to simulate a variety of charging types that may occur during the no-load charging process, in order to improve the efficiency of line verification and the correctness of verification results.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the descriptions of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only of the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings without paying creative efforts.

Fig. 1 is a schematic diagram of the implementation flow of the line no-load charging vector inspection method provided by the embodiment of the present invention;

Fig. 2 is a circuit diagram of the line no-load charging vector inspection provided by the embodiment of the present invention;

Fig. 3 is a circuit diagram of a single-circuit line no-load charging vector inspection provided by an embodiment of the present invention;

Fig. 4 is a circuit diagram of the no-load charging vector inspection of the line provided by the embodiment of the present invention at the break in the intermediate substation;

Fig. 5 is a circuit diagram of the no-load charging vector inspection of the double-circuit line provided by the embodiment of the present invention;

Fig. 6 is a circuit diagram of a circuit with high anti-no-load charging vector inspection provided by an embodiment of the present invention.

detailed description

In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. It will be apparent, however, to one skilled in the art that the invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to illustrate the technical solutions of the present invention, specific examples are used below to illustrate.

Fig. 1 shows a schematic diagram of the implementation flow of the line no-load charging vector inspection method provided by the embodiment of the present invention, which is described in detail as follows:

Step S101: setting L substation, M substation and N substation.

Referring to Fig. 2, it shows the circuit diagram of the line no-load charging vector inspection provided by the embodiment of the present invention, the wiring mode of the L substation, the M substation and the N substation is a 3/2 wiring mode; the L substation and the M substation The M substation is connected to the N substation through a line II, and both ends of the line I and the line II are provided with shunt reactors capable of controlling switching.

It is worth noting that in FIG. 2 there is also a line between the circuit breaker 5012 and the circuit breaker 5013 for connecting other lines or substations, so that the L substation forms a 3/2 connection mode. However, the line between the circuit breaker 5012 and the circuit breaker 5013 does not affect the inspection result of the circuit no-load vector inspection, therefore, the outgoing connection relationship between the circuit breaker 5012 and the circuit breaker 5013 is not shown in the figure. Similarly, between the circuit breaker 5032 and the circuit breaker 5033 of the M substation, between the circuit breaker 5042 and the circuit breaker 5043, and between the circuit breaker 5052 and the circuit breaker 5053 of the N substation, there is an outgoing line for connecting other lines or substations.

Step S102: By changing the connection mode between the L substation, the M substation and the N substation, determine the no-load charging of the single-circuit line, the no-load charging of the line at the break of the substation, the no-load charging of the double-circuit line, and the no-load charging of the line with high resistance Vector of Line Protection and Circuit Breaker Protection.

When using the line diagram of line no-load charging vector inspection to simulate the vectors of line protection and circuit breaker protection corresponding to different charging types, it is necessary to change the connection mode between the three substations, and then judge the line protection and circuit breaker protection according to the conventional vector judgment standard. Vector of circuit breaker protection.

It is easy to understand that the capacitance of the line is related to the length of the line and the radius of the line, and the capacitance of the line is proportional to the length of the line, and the capacitance of the line is also proportional to the radius of the line. The distance of transmission lines for 500kV ultra-high voltage new lines is generally tens of kilometers to more than one hundred kilometers, and the distance of transmission lines for 1000kV UHV new lines is generally more than hundreds of kilometers. Therefore, the length of transmission lines is relatively long. At the same time, for new 500kV ultra-high voltage lines and new 1000kV ultra-high voltage lines, in order to suppress corona discharge and reduce line reactance, the erection method of split conductors is usually adopted, and the erection method of split conductors can be equivalent to increasing the radius of transmission lines . Due to the long length of the transmission line and the large radius of the transmission line, the capacitance of the line is large, so that the line presents a large amount of capacitive power. When a large amount of capacitive power passes through inductive components such as system transformers and transmission lines, the terminal voltage will increase, which is the so-called "capacity rise" phenomenon, and then determine the vectors of line protection and circuit breaker protection corresponding to different charging types.

Optionally, the L substation includes one complete string, the M substation includes two complete strings, and the N substation includes one complete string; the line I is respectively connected to the L substation and the M substation, and the II line is respectively connected to the M substation and the N substation; three sequentially connected circuit breakers are set on the one complete string.

The above connection method is the general connection method of the no-load charging vector inspection system. For the vector inspection of different charging types, only certain modifications need to be made on the basis of the above connection method.

Optionally, by changing the connection mode between L substation, M substation and N substation, determine the vector of line protection and circuit breaker protection during no-load charging of single circuit line, specifically including:

The L substation is connected to the M substation through the line I, the M substation includes a complete string, and the shunt reactor is cut off in the line I;

The substation L charges the substation M, and determines the line protection vector of the L side of the I line according to the charging situation; where, the L side line of the I line is represented as the L side line of the line I;

Determine the size of the empty charging current on the L side of the I line according to the length of the line I;

According to the polarity of the CT coil protected by the circuit breaker, the vector of the circuit breaker protection of the L substation is determined.

See Figure 3, which shows the circuit diagram of the no-load charging vector inspection of a single-circuit line. It is only necessary to set up the L substation and the M substation, and both the L substation and the M substation only need a complete string to simulate the no-load charging vector inspection of a single-circuit line. . Among them, line 10 of L substation is represented as #1 bus, line 11 of M substation is represented as #1 bus, line 13 of L substation is represented as #2 bus, and line 14 of M substation is represented as #2 bus. The line 16 between the substations is indicated as line I. The vector check analysis results are as follows:

First, when the L substation is charging the line I through the #1 bus 10 through the circuit breaker 5011, a vector check is performed on the line protection on the L side of the I line and the circuit breaker 5011. Through the analysis of the above-mentioned transmission lines, when the "capacity rise" phenomenon occurs on the line, the relationship between the voltage and current of the I-line line protection is: the current leads the voltage by 90°, and pure capacitive reactive power is generated. Then calculate the size of the capacitive current according to the length of the line I. For the vector judgment of the circuit breaker 5011 in the L substation: Since the circuit breaker 5011 is a side switch circuit breaker, the CT polarity of the side switch circuit breaker is consistent with the CT polarity of the I-line line protection, so the protection vector of the circuit breaker 5011 is also The current leads the voltage by 90°.

Second, when the L substation is charging the line I via the #2 bus 13 via the circuit breaker 5012 , a vector check is performed on the line protection on the L side of the I line and the circuit breaker 5012 . Wherein, the relationship between the voltage and current of the I-line line protection is the same as that of the I-line line protection when the L substation charges the line I through the #1 bus 10 through the circuit breaker 5012 . Similarly, the size of the capacitive current is calculated according to the length of the line I. For the vector of the circuit breaker 5012 in the L substation, it is judged that: since the circuit breaker 5012 is a medium switch circuit breaker, the protection vector of the medium switch circuit breaker is related to the position of the CT coil used by the medium switch circuit breaker. Specifically, when the CT coil protected by the middle switch circuit breaker 5012 is on the side close to the line I, the vector direction of the protection vector of the middle switch circuit breaker 5012 is opposite to that of the line I protection, and the voltage leads the current by 90°; When the CT coil protected by the switch circuit breaker 5012 is on the side away from the line I, the vector protected by the switch circuit breaker 5012 is in the same direction as the vector protected by the line I, and the current leads the voltage by 90°.

Optionally, by changing the connection mode between L substation, M substation and N substation, determine the vector of line protection and circuit breaker protection when the line is charged at the break of the substation without load, specifically including:

The L substation is connected to the M substation through the line I, and the M substation is connected to the N substation through the line II. The M substation includes a first complete string and a second complete string, and the first complete string of the M substation It is connected to the line I, the second complete string of the M substation is connected to the line II, the shunt reactor is cut off in the line I, and the shunt reactor is cut off in the line II;

Substation L is charging for substation M, and the vector of line protection on the L side of line I is determined according to the charging situation; the size of the empty charging current on the L side of line I is determined according to the total length of line I and line II; according to the CT coil protected by the circuit breaker in substation L The polarity of the L substation determines the protection vector of the circuit breaker;

M substation is charging for N substation, according to the charging situation, determine the protection vector of I-line M-side line, and determine the size of empty charging current on I-line M-side according to the length of line II; according to the circuit breaker protection in the first complete string of M substation The polarity of the CT coils, determining the vector for circuit breaker protection in the first complete string of substation M;

M substation is charging for N substation, according to the charging situation, determine the vector of line protection on M side of line II, and determine the size of empty charging current on M side of line II according to the length of line II; according to the circuit breaker protection in the second complete string of substation M The polarity of the CT coils, determines the vector for circuit breaker protection in the second complete string of substation M.

Refer to Figure 4, which shows the circuit diagram of the vector inspection when the line is charged with no load at the break of the substation. It is necessary to set up the L substation, the M substation and the N substation. At the same time, a complete string needs to be set up between the L substation and the N substation, and M needs to be set Two complete strings can simulate the vector inspection of no-load charging of the line at the substation breach. Among them, the line 10 of L substation is represented as #1 bus, the line 11 of M substation is represented as #1 bus, the line 12 of N substation is represented as #1 bus; the line 13 of L substation is represented as #2 bus, the line of M substation 14 represents the #2 bus, and the line 15 of the N substation is represented as the #2 bus; the line 16 between the L substation and the first complete string of the M substation is represented as the line I, and the second complete string of the M substation and the N substation Line 17 of is denoted as Line II. Specifically, when judging the vectors of the line protection on the L side of the I line, the M side of the I line, and the M side of the II line, and the vectors of the circuit breaker protection corresponding to the line protection, it can be divided into the following four situations in detail:

First: the L side uses the #1 bus 10 to charge the line I through the circuit breaker 5011, and the M side uses the #1 bus 11 to charge the line II through the circuit breaker 5031 and the circuit breaker 5041. At this time, the two ends of the I line and the II line M Check the vector of side line protection, and check the vectors protected by circuit breakers 5011, 5031 and 5041 at the same time.

Similar to the result of the no-load charging vector inspection of single-circuit lines, the relationship between the voltage and current of the line protection on the L side of the I line is also: the current leads the voltage by 90°, and pure capacitive reactive power is generated. The empty charging current of the line is related to the length of the line behind the circuit breaker. Therefore, it is necessary to calculate the capacitive current on the L side of the line I according to the total length of the line I and the line II. The protection vector of the I-line L-side circuit breaker 5011 is consistent with the vector of the I-line L-side circuit protection, and the current leads the voltage by 90°.

The relationship between the voltage and current of the line protection on the M side of the II line is also: the current leads the voltage by 90°, and generates pure capacitive reactive power. Calculate the magnitude of the capacitive current on the M side of the line II according to the length of the line II. The protection vector of the circuit breaker 5041 on the M side of the II line is consistent with the line protection vector on the M side of the II line, and the current leads the voltage by 90°.

The relationship between the voltage and current of the line protection on the M side of the I line is opposite to the relationship between the voltage and current of the line protection on the M side of the II line. The voltage leads the current by 90° and absorbs pure capacitive reactive power. Similarly, the magnitude of the capacitive current on the side M of line I is calculated according to the length of line II. The protection vector of the I-line M-side circuit breaker 5031 is consistent with the vector of the I-line M-side circuit protection, and the voltage leads the current by 90°.

Second: the L side uses the #1 bus 10 to charge the line I through the circuit breaker 5011, and the M side uses the #2 bus 14 to charge the line II through the circuit breaker 5032 and the circuit breaker 5042. At this time, both ends of the I line and the II line M Check the vector of side line protection, and check the vectors protected by circuit breakers 5011, 5031 and 5041 at the same time.

When M substation uses #2 busbar to charge line II, the protection vectors on both sides of line I, line II on M side and the vector protected by circuit breaker 5011 are the same as those on both sides of line I and line II on M side in the first case The line protection vector and the vector protected by circuit breaker 5011 are the same, the difference lies in the vector inspection of the medium switch circuit breaker 5032 and 5042 of the M substation, the vectors of the medium switch circuit breaker 5032 and 5042 and the corresponding line protection vector and the medium switch circuit breaker adopt The position of the CT coil is related. When the CT coil used by the circuit breaker 5032 is close to the side of the line I, the vector of the circuit breaker 5032 is opposite to the vector protected on the M side of the line I, that is, the current leads the voltage by 90°; when the CT coil used by the circuit breaker 5032 is far away from On one side of the line I, the vector of the circuit breaker 5032 is the same as the vector protected on the line M side of the line I, that is, the voltage leads the current by 90°. The analysis method for the circuit breaker 5042 is the same as that of the circuit breaker 5032. When the CT coil used by the circuit breaker 5042 is on the side close to the line II, the vector of the circuit breaker 5042 is opposite to the protection vector of the line M side of the line II, that is, the voltage leads the current by 90° ; When the CT coil used by the circuit breaker 5042 is on the side away from the line II, the vector of the circuit breaker 5042 is the same as the vector protected on the M side of the line II, that is, the current leads the voltage by 90°.

Third: The L side uses the #2 bus 13 to charge the line I through the circuit breaker 5012, and the M side uses the #1 bus 11 to charge the line II through the circuit breaker 5031 and the circuit breaker 5041. At this time, both sides of the I line and II line M The side line protection carries out vector inspection, and the vectors protected by circuit breakers 5012, 5031 and 5041 are checked at the same time.

At this time, the protection vectors on both sides of the I line and the M side of the II line and the protection vectors of the circuit breaker 5031 and the circuit breaker 5041 are the same as the protection vectors on both sides of the I line and the M side of the II line in the first case, and the circuit breaker 5031 and the circuit breaker The vector protected by the device 5041 is exactly the same. The protection vector of the circuit breaker 5012 is related to the protection vector of the corresponding I-line line and the position of the CT coil used, and will not be repeated here.

Fourth: The L side uses the #2 bus 13 to charge the line I through the circuit breaker 5012, and the M side uses the #2 bus 14 to charge the line II through the circuit breaker 5032 and the circuit breaker 5042. At this time, both sides of the I line and II line M The side circuit protection carries out vector inspection, and the vectors protected by circuit breakers 5012, 5032 and 5042 are checked at the same time.

At this time, the protection vectors on both sides of the I line and the M side of the II line are completely consistent with the protection vectors on both sides of the I line and the M side of the II line in the first case. The protection vectors of the circuit breaker 5012 , the circuit breaker 5032 and the circuit breaker 5042 are respectively related to the corresponding line protection vectors and the positions of the CT coils used, and will not be repeated here.

It is easy to understand that in the above four cases, the line protection vectors on both sides of the I line and the M side of the II line are the same, and the vector of the circuit breaker protection is related to whether the circuit breaker is a side switch circuit breaker or a middle switch circuit breaker. When using When the side switch circuit breaker is used, the protection vector of the circuit breaker is consistent with the line protection vector of the corresponding side; when the middle switch circuit breaker is used, the protection vector of the circuit breaker is related to the position of the CT coil used. If the position of the CT coil used When it is close to one side of the line, it is opposite to the corresponding line vector, and when the position of the adopted CT coil is far away from the line side, it is the same as the corresponding line vector.

Optionally, by changing the connection mode among L substation, M substation and N substation, the vectors of line protection and circuit breaker protection during double-circuit line no-load charging are determined, specifically including:

The L substation is connected to the M substation through the line I, and the M substation is connected to the N substation through the line II; the N substation is set on the L substation, and the M substation includes the first complete string and the second complete string The first complete string of the M substation is connected to the line I, the second complete string of the M substation is connected to the line II, the shunt reactor is cut off in the line I, and the shunt reactor is cut off in the line II;

L substation is charging for M substation, and the vector of line protection on the L side of line I is determined according to the charging situation; the size of the empty charging current on the L side of line I is determined according to the total length of line I and line II; according to the CT of the circuit breaker protection in the L substation The polarity of the coil, which determines the vector of the circuit breaker protection of the L substation;

Substation M charges substation L, determines the line protection vector of I-line M side according to the charging situation, and determines the empty charging current of I-line M side according to the length of line II; according to the circuit breaker protection in the first complete string of M substation The polarity of the CT coils, determining the vector for circuit breaker protection in the first complete string of substation M;

Substation M charges for substation L, determines the line protection vector of line II on the M side according to the charging situation, and determines the empty charging current on the M side of line II according to the length of line II; according to the circuit breaker protection in the second complete string of substation M The polarity of the CT coils, determines the vector for circuit breaker protection in the second complete string of substation M.

Referring to Fig. 5, it shows the circuit diagram of the no-load charging vector inspection of the double-circuit line. Obtained in L substation. The L substation charges the M substation with no-load through the I line 14, and the M substation charges the L substation with no-load through the II line 15.

In this case, substation L may use #1 bus 10 or #2 bus 12 to charge line I, and M substation may also use #1 bus 11 or #2 bus 13 to charge line II, no matter which bus is used for the line For charging, it is also necessary to check the vectors of the line protection on both sides of the I line and the M side of the II line, and at the same time check the vector of the circuit breaker protection. The specific vector inspection results are consistent with the inspection results of the no-load charging vector inspection of the line at the break of the substation, and will not be repeated here.

Optionally, the determination of the line protection and circuit breaker protection vectors when the line is charged with high resistance to no-load by changing the connection mode between the L substation, the M substation and the N substation specifically includes:

The L substation is connected to the M substation by line I, the M substation is connected to the N substation by line II, the M substation involves a first complete string and a second complete string, the first complete string of the M substation Connected to the line I, the second complete string of the M substation is connected to the line II, a shunt reactor is put into the line I, and a shunt reactor is put into the line II;

Substation L is charged for substation M, and the vector of line protection on the L side of line I is determined according to the charging situation; the empty charging on the L side of line I is determined according to the total length of line I and line II and the capacity of the shunt reactors put into line I and line II The size of the flow; according to the polarity of the CT coil of the circuit breaker protection in the L substation, determine the vector of the circuit breaker protection of the L substation;

The M substation charges the N substation, and determines the line protection vector of the M side of the I line according to the charging situation, and determines the empty charging current of the M side of the I line according to the length of the line II and the capacity of the shunt reactor put into the line II; according to the M substation The polarity of the CT coil protected by the circuit breaker in the first complete string of M substation determines the vector of the circuit breaker protection in the first complete string of M substation;

The M substation charges the N substation, and determines the line protection vector of the M side of the II line according to the charging situation, and determines the empty charging current of the M side of the II line according to the length of the line II and the capacity of the shunt reactor put into the line II; according to the M substation The polarities of the CT coils protected by the circuit breakers in the second complete string of the M substation determine the vectors protected by the circuit breakers in the second complete string of the substation M.

Referring to Figure 6, it shows the circuit diagram of the line with high anti-no-load charging vector inspection. Change, put shunt reactors on line I and line II between substations, the number of shunt reactors put into a line can only be one, and shunt reactor 18 or shunt reactor 19 can be specified on line I, in The parallel reactor 20 or the parallel reactor 21 is specified on the line II, and the capacity of the parallel reactor can be set. Similarly, the inspection results of line protection on both sides of line I, line M side of line II, line protection of line II and vector protection of the circuit breaker with high anti-no-load charging vector inspection are consistent with the inspection results of the no-load charging vector inspection of the line at the substation breach. I won't go into details here.

The difference is that when the line is equipped with a shunt reactor, the shunt reactor can supplement the reactive current of the line where the shunt reactor is located, and the shunt reactor 18 or shunt reactor 19 of line I can compensate the reactive current of line I, The shunt reactor 20 or shunt reactor 21 of the line II can compensate the reactive current of the line II. Among them, according to the capacity of the input shunt reactor, determine the magnitude of the I-line current compensated by the shunt reactor.

Exemplarily, for a new ultra-high voltage line of 500kV, when the capacity of the shunt reactor put into the line is 50Mvar, the capacitive current for high-resistance compensation can be calculated as: Among them, 525kV represents the actual voltage of 500kV, and the high resistance compensation capacitor current is 55A. For the 500kV ultra-high voltage new line, the empty charging capacity current per kilometer is 1.25, therefore, when the line length is 80km, the reactive current can be calculated as: 80×1.25=100A; when a 50Mvar shunt reactor is put into the line , The reactive current is 80×1.25-55=45A. It can be seen that the reactive current of the line can be compensated after setting the shunt reactor in the line.

The above line no-load charging vector inspection method determines the no-load charging of single-circuit lines, no-load charging of lines at substation breaks, and no-load charging of double-circuit lines by setting L substation, M substation and N substation and changing the connection mode between the three substations. The vector of line protection and circuit breaker protection when charging and line with high resistance to no-load charging; among them, the wiring mode of the substation is 3/2 wiring mode, the L and N substations include a complete string, and the M substation includes two complete strings Three circuit breakers are set on a complete string; L and M substations are connected through line I, and M and N substations are connected through line II, and both ends of line I and line II are equipped with controllable switching Shunt reactor; by changing the connection mode of the substation to simulate a variety of charging types in the no-load charging process, so as to improve the efficiency of line verification and the correctness of verification results.

The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still implement the foregoing embodiments Modifications to the technical solutions recorded in the examples, or equivalent replacement of some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should be included in within the protection scope of the present invention.

Claims (6)

1. a kind of unloaded charging vector angle method method of circuit, it is characterised in that including：

L transformer stations, M transformer stations and N transformer stations are set；Wherein, the mode of connection of the L transformer stations, M transformer stations and N transformer stations For 3/2 mode of connection；The L transformer stations are connected with M transformer stations by circuit I, and the M transformer stations and N transformer stations pass through circuit II is connected, and the both ends of the circuit I and circuit II are provided with the shunt reactor of controllable switching；

By changing the connected mode between L transformer stations, M transformer stations and N transformer stations, the unloaded charging of single back line, circuit are determined Route protection and breaker when transformer station's cut zero load is charged, double-circuit line zero load is charged and the high anti-zero load of circuit band is charged The vector of protection.

2. the unloaded charging vector angle method method of circuit as claimed in claim 1, it is characterised in that the L transformer stations include one Individual complete string, M transformer stations include two complete strings, and N transformer stations include a complete string；Circuit I connects the L transformer stations respectively With the M transformer stations, II circuits connect the M transformer stations and the N transformer stations respectively；Three are set on one complete string The breaker being sequentially connected.

3. the unloaded charging vector angle method method of circuit as claimed in claim 2, it is characterised in that described by changing L power transformations Stand, the route protection and breaker protection that the connected mode between M transformer stations and N transformer stations determines that single back line is unloaded when charging Vector, specifically include：

The L transformer stations are connected with M transformer stations by circuit I, the M transformer stations include one and completely gone here and there, in the circuit I Cut off shunt reactor；

L transformer stations are charged for M transformer stations, and the vector of I line L sides route protection is determined according to charge condition；Wherein, I lines L side lines road It is expressed as circuit I L side lines road；

The size of the empty charging stream in I line L sides is determined according to circuit I length；

According to the polarity of the CT coils of breaker protection, the vector of the breaker protection of L transformer stations is determined.

4. the unloaded charging vector angle method method of circuit as claimed in claim 1, it is characterised in that described by changing L power transformations Stand, the connected mode between M transformer stations and N transformer stations determines route protection of the circuit in the unloaded charging of transformer station cut and disconnected The vector of road device protection, is specifically included：

The L transformer stations are connected with M transformer stations by circuit I, the M transformer stations are connected with N transformer stations by circuit II, The M transformer stations include the first complete string and the second complete string, and the first complete string of the M transformer stations is connected with circuit I, described The complete string of the second of M transformer stations is connected with circuit II, and shunt reactor is cut off in the circuit I, is cut off simultaneously in the circuit II Join reactor；

L transformer stations are charged for M transformer stations, and the vector of I line L sides route protection is determined according to charge condition；According to circuit I and circuit II total length determines the size of the empty charging stream in I line L sides；According to the polarity of the CT coils of breaker protection in L transformer stations, it is determined that The vector of the breaker protection of L transformer stations；

M transformer stations charge for N transformer stations, the vector of I line M sides route protection are determined according to charge condition, according to circuit II length Degree determines the size of the empty charging stream in I line M sides；The pole of the CT coils of breaker protection in the first of M transformer stations the complete string Property, determine the vector of the breaker protection in the first complete string of M transformer stations；

M transformer stations charge for N transformer stations, the vector of II line M sides route protection are determined according to charge condition, according to circuit II length Degree determines the size of the empty charging stream in II line M sides；The pole of the CT coils of breaker protection in the second of M transformer stations the complete string Property, determine the vector of the breaker protection in the second complete string of M transformer stations.

5. the unloaded charging vector angle method method of circuit as claimed in claim 1, it is characterised in that described by changing L power transformations Stand, the route protection and breaker protection that the connected mode between M transformer stations and N transformer stations determines that double-circuit line is unloaded when charging Vector, specifically include：

The L transformer stations are connected with M transformer stations by circuit I, the M transformer stations are connected with N transformer stations by circuit II； The N transformer stations are set onto L transformer stations, the M transformer stations include the first complete string and the second complete string, the M power transformations The the first complete string stood is connected with circuit I, and the second complete string of the M transformer stations is connected with circuit II, is cut off in the circuit I Shunt reactor, shunt reactor is cut off in the circuit II；

L transformer stations are charged for M transformer stations, and the vector of I line L sides route protection is determined according to charge condition；According to circuit I and circuit II total length determines the size of the empty charging stream in I line L sides；The polarity of the CT coils of breaker protection in L transformer stations, really Determine the vector of the breaker protection of L transformer stations；

M transformer stations charge for L transformer stations, the vector of I line M sides route protection are determined according to charge condition, according to circuit II length Degree determines the size of the empty charging stream in I line M sides；The pole of the CT coils of breaker protection in the first of M transformer stations the complete string Property, determine the vector of the breaker protection in the first complete string of M transformer stations；

M transformer stations charge for L transformer stations, the vector of II line M sides route protection are determined according to charge condition, according to circuit II length Degree determines that the sky of II line M sides fills size of current；The pole of the CT coils of breaker protection in the second of M transformer stations the complete string Property, determine the vector of the breaker protection in the second complete string of M transformer stations.

6. the unloaded charging vector angle method method of circuit as claimed in claim 1, it is characterised in that described by changing L power transformations Stand, the connected mode between M transformer stations and N transformer stations determines route protection when the high anti-zero load of circuit band is charged and breaker guarantor The vector of shield, is specifically included：

The L transformer stations are connected with M transformer stations by circuit I, the M transformer stations are connected with N transformer stations by circuit II, The M transformer stations are related to the first complete string and the second complete string, and the first complete string of the M transformer stations is connected with circuit I, described The complete string of the second of M transformer stations is connected with circuit II, and shunt reactor is put into the circuit I, is put into simultaneously in the circuit II Join reactor；

L transformer stations are charged for M transformer stations, and the vector of I line L sides route protection is determined according to charge condition；According to circuit I and circuit The capacity of the shunt reactor put into II total length and circuit I and circuit II determines the size of the empty charging stream in I line L sides； According to the polarity of the CT coils of breaker protection in L transformer stations, the vector of the breaker protection of L transformer stations is determined；

M transformer stations charge for N transformer stations, the vector of I line M sides route protection are determined according to charge condition, according to circuit II length The capacity of shunt reactor put into degree and circuit II determines the size of the empty charging stream in I line M sides；According to the of M transformer stations The polarity of the CT coils of breaker protection in one complete string, determine breaker protection in the first complete string of M transformer stations Vector；

M transformer stations charge for N transformer stations, the vector of II line M sides route protection are determined according to charge condition, according to circuit II length The capacity of shunt reactor put into degree and circuit II determines the size of the empty charging stream in II line M sides；According to the of M transformer stations The polarity of the CT coils of breaker protection in two complete strings, determine breaker protection in the second complete string of M transformer stations Vector.