CN112968461B - Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation - Google Patents

Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation Download PDF

Info

Publication number
CN112968461B
CN112968461B CN202110183561.XA CN202110183561A CN112968461B CN 112968461 B CN112968461 B CN 112968461B CN 202110183561 A CN202110183561 A CN 202110183561A CN 112968461 B CN112968461 B CN 112968461B
Authority
CN
China
Prior art keywords
phase
closing
converter transformer
bridge
bridge converter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110183561.XA
Other languages
Chinese (zh)
Other versions
CN112968461A (en
Inventor
陈忠
杨为
胡迪
韩平平
童青洋
孙浩然
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd
Hefei University of Technology
Original Assignee
Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd
Hefei University of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd, Hefei University of Technology filed Critical Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd
Priority to CN202110183561.XA priority Critical patent/CN112968461B/en
Publication of CN112968461A publication Critical patent/CN112968461A/en
Application granted granted Critical
Publication of CN112968461B publication Critical patent/CN112968461B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/001—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection limiting speed of change of electric quantities, e.g. soft switching on or off
    • H02H9/002—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection limiting speed of change of electric quantities, e.g. soft switching on or off limiting inrush current on switching on of inductive loads subjected to remanence, e.g. transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • H02J2003/365—Reducing harmonics or oscillations in HVDC
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Abstract

The invention discloses a converter transformer phase selection closing excitation inrush current suppression method based on magnetic biasing simulation, which comprises the following steps: 1. estimating three-phase residual magnetism values of the converter transformers of the Y bridge and the D bridge; 2. extracting and considering the influence result of a series closing resistor of the circuit breaker on the closing bias amplitude and the phase, and constructing a bias function; 3. and comparing the residual magnetism estimated when the converter transformer is switched off with the magnetic biasing function to obtain the proper switching-on time of the converter transformer. The method can utilize the mutual offset of the residual magnetism during the opening and the bias magnetism during the closing of the converter transformer, effectively improve the excitation inrush current suppression effect of the converter transformer, is beneficial to suppressing the excitation inrush current caused by the closing and charging of the converter transformer during the overhaul and the change of the operation mode of a high-voltage direct-current transmission project, and solves the problem of phase change failure caused by the excitation inrush current of the converter transformer.

Description

Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation
Technical Field
The invention relates to a converter transformer phase selection closing magnetizing inrush current suppression method based on magnetic biasing simulation, and belongs to the technical field of power transformer magnetizing inrush current suppression.
Background
The ultra-high voltage direct current transmission has the characteristics of large transmission capacity and long distance, and is a main transmission technology for realizing the transmission of electric power of large energy bases in the southwest, northwest and the like of China. The converter transformer is a power transformer for connecting a converter bridge and an alternating current system, is one of core equipment for direct current transmission, and the basic structure of the ultra-high voltage direct current transmission converter is generally formed by serially connecting two 6-pulse converter bridges into a 12-pulse converter bridge, meanwhile, in two groups of converter transformers, one group adopts Y-Y connection and the other group adopts Y-delta connection, and two groups of phase-change voltages with equal amplitude and 30-degree phase difference are provided for the two serially connected converter bridges by utilizing different connection methods of secondary side windings of the transformers. Due to the nonlinear saturation characteristic of the transformer iron core, in the process of closing and charging of the transformer, the iron core is easily saturated under the action of an abrupt direct-current component, the excitation reactance is sharply reduced, the excitation current is sharply increased, and the direct-current component enables the excitation inrush current waveform to be deviated to one side of a time axis to be in a sharp-top shape. The maximum instantaneous excitation surge current amplitude of the switch-on can reach 8-10 times of rated current and about 100 times of no-load current, meanwhile, the surge current contains a large harmonic component (mainly low-order harmonic), so that the commutation voltage of a connected alternating current system is seriously distorted, the normal commutation of a commutation valve set is inevitably influenced, the commutation failure can be caused in serious cases, if the continuous commutation failure is caused, the direct current system is locked, the power of a receiving end alternating current system is seriously lacked, and the safe and stable operation of a power grid is greatly damaged.
Common magnetizing inrush current suppression measures at the present stage are mainly series connection switch-on resistors or phase selection switch-on, but from engineering practice, the suppression effects of the two measures still have a larger improvement space. The series connection switching-on resistance measure is limited by the selection of a switching-on resistance value and the input time of the resistance, and sometimes the situation of high switching-on inrush current still occurs; after the phase selection switching-on measure is adopted, the phase selection switching-on operation depends on a fixed switching-on phase, namely, the three phases of the Y-bridge converter transformer are respectively switched on the voltage peak, the first switching-on phase of the D-bridge converter transformer is switched on the voltage peak, and the other two phases are switched on in a period lagging the first switching-on phase 1/4. Therefore, when considering the maintenance and switching operation modes of the high-voltage direct-current transmission system, the magnetizing inrush current suppression effect of the measures is limited when the converter transformer is charged, and the magnetizing inrush current suppression measures of the converter transformer of the high-voltage direct-current transmission system considering the influence of remanence and closing resistance need to be further improved.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a converter transformer phase selection switching-on magnetizing inrush current suppression method based on magnetic biasing simulation, so that the magnetizing inrush current caused by switching-on charging of a converter transformer can be effectively suppressed, the phase-change voltage distortion condition of a receiving-end alternating current system is improved, the phase-change failure caused by phase-change voltage distortion is reduced, and the safe and stable operation of a receiving-end power grid is maintained.
The technical scheme adopted by the invention for solving the technical problems is as follows:
1. a converter transformer phase selection closing excitation inrush current suppression method based on bias simulation is characterized by being applied to a converter transformer no-load closing circuit consisting of a Y bridge converter transformer and a D bridge converter transformer and being carried out according to the following steps:
step 1, collecting three-phase voltages of primary sides of converter transformers of a Y bridge and a D bridge in real time;
step 2, detecting three-phase voltage at the opening moment according to the converter transformers of the Y bridge and the D bridge, and estimating a three-phase residual magnetism value by using a voltage integration method;
and 3, respectively selecting different phase selection and closing strategies by the Y-bridge converter transformer and the D-bridge converter transformer to execute phase selection and closing control of the three-phase circuit breaker:
for the Y-bridge converter transformer, calculating ideal closing time corresponding to three phases of the Y-bridge converter transformer according to a bias function and a lag angle under the influence of the series closing resistor by using the estimated three-phase residual magnetism value so as to execute the closing operation of a three-phase circuit breaker;
for the D-bridge converter transformer, determining a middle phase of a three-phase remanence value as a first phase, and calculating corresponding ideal closing time according to a bias function and a lag angle under the influence of a series closing resistor by using the estimated first phase remanence value so as to execute the closing operation of a three-phase circuit breaker; then, determining the phase with the minimum remanence value in the three-phase remanence values as a secondary phase-closing, redefining the remanence value of the secondary phase-closing and a half of the remanence value of the primary phase-closing as the remanence value of the secondary phase-closing, calculating the corresponding ideal closing time according to the bias function and the lag angle under the influence of the series closing resistance by using the redefined remanence value, and performing closing operation by using the three-phase circuit breaker; the last closed phase of the D-bridge converter transformer executes the closing operation of the three-phase circuit breaker at any time after the second closed phase is closed;
And 4, taking the average value of the three-phase ideal closing time of the Y-bridge converter transformer and the D-bridge converter transformer as the three-phase simultaneous closing time of the Y-bridge converter transformer and the D-bridge converter transformer to close, and after the closing resistance of the three-phase circuit breaker is over the input time, enabling the closing resistance to be in short circuit and quit so as to complete the control of the excitation inrush current suppression.
The method for suppressing the magnetizing inrush current during the phase selection and closing of the converter transformer is characterized in that the ideal closing time in the step 3 is calculated according to the following process:
for a Y-bridge converter transformer, calculating the ideal three-phase closing time by using the formula (1):
Figure BDA0002942124680000021
in the formula (1), tYA、tYB、tYCThe ideal three-phase closing time of the Y-bridge converter transformer is obtained; omega is angular frequency; psiYA、ψYB、ψYCEstimating a three-phase residual magnetism value for the Y-bridge converter transformer; psiYmThe switching-on magnetic bias peak value of the Y bridge converter transformer is obtained; t is tY_offsetIs the offset time of the Y-bridge converter transformer; t is torderPredicting the closing time; t is tsThe power frequency period is set;
for the D-bridge converter transformer, the ideal three-phase closing time is calculated by using the formula (2):
Figure BDA0002942124680000031
in the formula (2), tprime、tsecond、tfinalIdeal closing time of first phase closing, second phase closing and final phase closing of the D-bridge converter transformer is respectively set; omega is angular frequency; psiprime_rem、ψsecond_remEstimation for first phase combination and second phase combination of D-bridge converter transformerA remanence value; psiDmThe current is the closing magnetic bias peak value of the D bridge converter transformer; t is t D_offsetIs the offset time of the converter transformer of the D bridge; t is torderPredicting the closing time; if the first phase, the second phase and the last phase are B phase or C phase, B corresponds to the ideal closing time
Figure BDA0002942124680000032
C corresponding ideal closing time plus
Figure BDA0002942124680000033
Wherein, tsIs the power frequency cycle.
The simultaneous closing time of the converter transformers with the Y bridge and the D bridge in the step 4 is calculated according to the following process:
if the first phase, the second phase and the last phase of the D-bridge converter transformer are respectively an A phase, a B phase and a C phase, the simultaneous closing time is as follows:
Figure BDA0002942124680000034
in the formula (3), tA、tB、tCThe switching-on time of the A phase, the B phase and the C phase of the converter transformer of the Y bridge and the D bridge is respectively.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention provides a method for inhibiting magnetizing inrush current of phase-selection switching-on of a converter transformer based on bias simulation, which utilizes the offset of switching-on after series connection of a switching-on resistor to be cancelled with the original switching-off residual magnetism, overcomes the limitations of selection of a switching-on resistance value and resistance input time limitation in a single measure and the limitation of phase-selection switching-on measures according to the inherent switching-on phase, effectively inhibits the magnetizing inrush current caused by switching-on charging of the converter transformer when a high-voltage direct-current transmission project is overhauled and the operation mode is changed, and reduces the risk of failure of phase-change of a valve bank of the converter during operation.
2. The invention only improves the phase selection and closing control of the three-phase circuit breaker, does not need to increase three-phase circuit breaker equipment of a converter station, and has good economy.
Drawings
FIG. 1 is a circuit diagram of a converter transformer no-load closing circuit of the present invention;
FIG. 2 is a closing control structure diagram of a converter transformer with Y bridge and D bridge according to the present invention;
FIG. 3 is an equivalent circuit diagram of the no-load closing of the converter transformer according to the present invention;
FIG. 4 is a diagram of the no-load closing excitation current of the Y-bridge converter transformer according to the present invention;
fig. 5 is a diagram of the no-load closing excitation current of the converter transformer with the bridge D of the invention.
Detailed Description
In this embodiment, as shown in fig. 1, the converter transformer no-load switching-on circuit is composed of a Y-bridge converter transformer and a D-bridge converter transformer, and the Y-bridge converter transformer and the D-bridge converter transformer include a single-phase double-winding transformer, a three-phase circuit breaker, and an ac power grid. The primary side of the Y-bridge converter transformer adopts a star connection method, wherein a neutral point is grounded, and the secondary side of the Y-bridge converter transformer also adopts a star connection method, wherein the neutral point is grounded through an infinite resistor; the primary side of the D-bridge converter transformer adopts a star connection method, the neutral point of the D-bridge converter transformer is grounded, and the secondary side of the D-bridge converter transformer adopts a delta connection method. The Y-bridge converter transformer and the D-bridge converter transformer are connected with a 500kV alternating current system through the same three-phase circuit breaker, 1500-ohm closing resistors are connected into the three-phase circuit breaker in series, and the closing resistors are in short circuit and quit after the three-phase circuit breaker is put into operation for 6 ms.
As shown in FIG. 2, the influence of the series closing resistor on the closing bias amplitude and phase is considered in the phase selection and closing control of the Y-bridge converter transformer, and psiYmTake 0.63pu, torderTaking 10s, tY_offsetFor a lag of 27 deg. corresponding to time, tY_lagAnd considering that the converter transformer remanence in the actual engineering does not exceed 0.7pu for B, C phases respectively lagging the corresponding time of 120 degrees and 240 degrees of the A phase, and multiplying the remanence by 0.7 after estimation. The phase selection and closing control of the D-bridge converter transformer considers the influence of the secondary side triangular wiring coupling, the residual magnetism of the secondary phase is added to half of the residual magnetism of the primary phase in the secondary phase closing, and the calculated value is redefined as the residual magnetism, psi, of the secondary phase closingDmTake 0.54pu, torderTake 10s, tD_offsetFor a lag of 40 deg. corresponding to time, tD_lagThe estimated remanence is also multiplied by 0.7 for B, C phases lagging the A phase by a time corresponding to 120 DEG and 240 DEG, respectively.
In order to study the influence of the remanence, a method commonly used in engineering for measuring and calculating the remanence is a voltage integration method, namely, the remanence is estimated by measuring the amplitude and the phase of primary side voltage and integrating the primary side voltage.
Figure BDA0002942124680000041
Wherein, UmIs the peak value of the grid voltage; omega is angular frequency; alpha is a voltage initial phase angle during closing; t is t0The voltage peak value corresponds to the moment; t is t1Is the moment of opening the gate.
As shown in fig. 3, when the converter transformer is switched on in the no-load state, the leakage flux is ignored, and the relationship between the grid voltage and the primary side voltage is:
Figure BDA0002942124680000042
In the formula (5), R ═ RT+Rm(ii) a i is an exciting current; u shapemIs the peak value of the grid voltage; alpha is the initial phase angle of the voltage when t is 0.
Solving the first order constant coefficient differential equation for ψ can result:
Figure BDA0002942124680000051
in the formula (6), the reaction mixture is,
Figure BDA0002942124680000052
is the steady state flux linkage peak; psirIs remanence;
Figure BDA0002942124680000053
is the impedance angle; tau is L/R and is a transient magnetic flux decay time constant; l ═ LT+Lm。
As can be seen from equation (6), the iron core flux linkage at the moment of switching-on is composed of a steady flux linkage and a transient flux linkage, where psirThe residual magnetism is used for opening the brake,
Figure BDA0002942124680000054
the direction is opposite to the steady-state flux linkage in order to resist the steady-state flux linkage instantaneous value suddenly increased in closing. After the circuit breaker is connected with a closing resistor in series, the peak value of the steady-state flux linkage is reduced, and the peak value of the magnetizing inrush current can be further suppressed; the impedance angle is reduced, and the steady-state component is
Figure BDA0002942124680000055
Obtaining a peak value, wherein the inrush current peak value is advanced due to the series connection of the closing resistor; the decay time constant is reduced and the decay of the transient component can be accelerated.
Therefore, after the closing resistor is connected in series, the influence result of the closing resistor on the closing magnetic bias amplitude and the phase can be extracted, a magnetic bias function is constructed, and a Y-bridge converter transformer is taken as an example:
ψYA＝ψYmsin(ω(t+tY_offset)) (7)
obtaining by solution:
Figure BDA0002942124680000056
the closing time of the converter transformer A with the Y bridge is as follows:
Figure BDA0002942124680000057
the switching-on time of the Y-bridge converter transformer A, B, C is as follows:
Figure BDA0002942124680000058
in the formula (10), t YA、tYB、tYCThe ideal switching-on time is the ideal three-phase switching-on time of the Y-bridge converter transformer; omega is angular frequency; psiYA、ψYB、ψYCEstimating three-phase remanence values for the Y-bridge converter transformer; psiYmA closing magnetic bias peak value of the Y-bridge converter transformer is obtained; t is tY_offsetIs the offset time of the Y-bridge converter transformer; t is torderPredicting the closing time; t is tsThe power frequency period is 0.02 s.
For the D-bridge converter transformer, calculating the ideal three-phase closing time according to the corresponding phase selection closing strategy:
Figure BDA0002942124680000061
in formula (11), tprime、tsecond、tfinalIdeal closing time of first phase closing, second phase closing and final phase closing of the D-bridge converter transformer is respectively set; omega is angular frequency; psiprime_rem、ψsecond_remEstimating remanence values for the first phase combination and the second phase combination of the D-bridge converter transformer respectively; psiDmThe current is the closing magnetic bias peak value of the D bridge converter transformer; t is tD_offsetIs the offset time of the converter transformer of the D bridge; t is torderPredicting the closing time; if the first phase, the second phase and the last phase are B phase or C phase, B corresponds to the ideal closing time
Figure BDA0002942124680000062
C corresponding ideal closing time plus
Figure BDA0002942124680000063
Wherein, tsThe power frequency period is 0.02 s.
And after the ideal three-phase closing time of the Y-bridge converter transformer and the D-bridge converter transformer is respectively calculated, taking the average value of the three-phase closing time of the Y-bridge converter transformer and the D-bridge converter transformer as the simultaneous three-phase closing time of the Y-bridge converter transformer and the D-bridge converter transformer. If the first phase, the second phase and the last phase of the D-bridge converter transformer are respectively an A phase, a B phase and a C phase, the simultaneous closing time is as follows:
Figure BDA0002942124680000064
In formula (12), tA、tB、tCThe switching-on time of the A phase, the B phase and the C phase of the converter transformer of the Y bridge and the D bridge is respectively.
The method for suppressing the current conversion, phase selection, closing and excitation inrush current based on the bias simulation specifically comprises the following steps:
step 1, collecting three-phase voltages of primary sides of converter transformers of a Y bridge and a D bridge in real time;
step 2, detecting three-phase voltage at the opening moment according to the converter transformers of the Y bridge and the D bridge, and estimating a three-phase residual magnetism value by using a voltage integration method;
and 3, respectively selecting different phase selection and closing strategies by the Y-bridge converter transformer and the D-bridge converter transformer to execute phase selection and closing control of the three-phase circuit breaker:
for the Y-bridge converter transformer, calculating ideal closing time corresponding to three phases of the Y-bridge converter transformer according to a bias function and a lag angle under the influence of the series closing resistor by using the estimated three-phase residual magnetism value so as to execute the closing operation of a three-phase circuit breaker;
for the D-bridge converter transformer, determining a middle phase of a three-phase remanence value as a first phase, and calculating corresponding ideal closing time according to a bias function and a lag angle under the influence of a series closing resistor by using the estimated first phase remanence value so as to execute the closing operation of a three-phase circuit breaker; then, determining the phase with the minimum remanence value in the three-phase remanence values as a secondary phase-closing, redefining the remanence value of the secondary phase-closing and a half of the remanence value of the primary phase-closing as the remanence value of the secondary phase-closing, calculating the corresponding ideal closing time according to the bias function and the lag angle under the influence of the series closing resistance by using the redefined remanence value, and performing closing operation by using the three-phase circuit breaker; the last closed phase of the D-bridge converter transformer executes the closing operation of the three-phase circuit breaker at any time after the second closed phase is closed;
And 4, taking the average value of the three-phase ideal closing time of the Y-bridge converter transformer and the D-bridge converter transformer as the three-phase simultaneous closing time of the Y-bridge converter transformer and the D-bridge converter transformer to close, and after the closing resistance of the three-phase circuit breaker is over the input time, enabling the closing resistance to be in short circuit and quit so as to complete the control of the excitation inrush current suppression.
The invention takes 3.013s switching-off time as an example to verify the effectiveness of the proposed magnetizing inrush current suppression method. The simulation result is shown in fig. 4 and 5, after the three phases of the Y-bridge converter transformer are switched on, only the steady-state component of sinusoidal fluctuation with the amplitude of 0.066kA exists, the remanence and the bias magnetism are effectively counteracted, the transient disturbance during switching-on is removed by the sum of the three-phase inrush currents, and the peak value after stabilization is only 0.02 kA; at the moment of three-phase switching-on of the D-bridge converter transformer, only a direct-current component with a peak value of 0.13kA is left, and the direct-current component is also stabilized to be a steady-state component with sinusoidal fluctuation of an amplitude of 0.066kA after rapid attenuation, remanence and bias magnetism are effectively counteracted, the peak value of the sum of three-phase inrush currents when the sum of the three-phase inrush currents is divided and switched on reaches 0.2kA, the peak value after stabilization is only 0.005kA, the peak values of three-phase excitation inrush currents after the Y, D-bridge converter transformer is switched on are smaller, and the requirement of excitation inrush current suppression is met.

Claims (1)

1. A converter transformer phase selection closing excitation inrush current suppression method based on bias simulation is characterized by being applied to a converter transformer no-load closing circuit consisting of a Y bridge converter transformer and a D bridge converter transformer and being carried out according to the following steps:
Step 1, collecting three-phase voltages of primary sides of converter transformers of a Y bridge and a D bridge in real time;
step 2, detecting three-phase voltage at the opening moment according to the converter transformers of the Y bridge and the D bridge, and estimating a three-phase residual magnetism value by using a voltage integration method;
and 3, respectively selecting different phase selection and closing strategies by the Y-bridge converter transformer and the D-bridge converter transformer to execute phase selection and closing control of the three-phase circuit breaker:
for the Y-bridge converter transformer, calculating ideal closing time corresponding to three phases of the Y-bridge converter transformer according to a bias function and a lag angle under the influence of the series closing resistor by using the estimated three-phase residual magnetism value so as to execute the closing operation of a three-phase circuit breaker;
for the D-bridge converter transformer, determining a middle phase of a three-phase remanence value as a first phase, and calculating corresponding ideal closing time according to a bias function and a lag angle under the influence of a series closing resistor by using the estimated first phase remanence value so as to execute the closing operation of a three-phase circuit breaker; then, determining the phase with the minimum remanence value in the three-phase remanence values as a secondary phase-closing, redefining the remanence value of the secondary phase-closing and a half of the remanence value of the primary phase-closing as the remanence value of the secondary phase-closing, calculating the corresponding ideal closing time according to the bias function and the lag angle under the influence of the series closing resistance by using the redefined remanence value, and performing closing operation by using the three-phase circuit breaker; the last closed phase of the D-bridge converter transformer executes the closing operation of the three-phase circuit breaker at any time after the second closed phase is closed;
The ideal closing time in the step 3 is calculated according to the following process:
for a Y-bridge converter transformer, calculating the ideal three-phase closing time by using the formula (1):
Figure FDA0003619110740000011
in the formula (1), tYA、tYB、tYCThe ideal three-phase closing time of the Y-bridge converter transformer is obtained; omega is angular frequency; psiYA、ψYB、ψYCEstimating a three-phase residual magnetism value for the Y-bridge converter transformer; psiYmThe switching-on magnetic bias peak value of the Y bridge converter transformer is obtained; t is tY_offsetIs the offset time of the Y-bridge converter transformer; t is torderPredicting the closing time; t is tsThe power frequency period is set;
for the D-bridge converter transformer, the ideal three-phase closing time is calculated by using the formula (2):
Figure FDA0003619110740000021
in the formula (2), tprime、tsecond、tfinalIdeal closing time of first phase closing, second phase closing and final phase closing of the D-bridge converter transformer is respectively set; omega is angular frequency; psiprime_rem、ψsecond_remEstimating remanence values for the first phase combination and the second phase combination of the D-bridge converter transformer respectively; psiDmThe current is the closing magnetic bias peak value of the D bridge converter transformer; t is tD_offsetIs the offset time of the converter transformer of the D bridge; t is torderPredicting the closing time; if the first phase, the second phase and the last phase are B phase or C phase, B corresponds to the ideal closing time
Figure FDA0003619110740000022
C corresponding ideal closing time plus
Figure FDA0003619110740000023
Wherein, tsThe power frequency period is set;
step 4, taking the average value of the three-phase ideal closing time of the Y-bridge converter transformer and the D-bridge converter transformer as the three-phase simultaneous closing time of the Y-bridge converter transformer and the D-bridge converter transformer to close, and after the closing resistance of the three-phase circuit breaker is over the input time, the closing resistance is in short circuit and exits to complete the control of the excitation inrush current suppression;
The simultaneous closing time of the converter transformers of the Y bridge and the D bridge is calculated according to the following process:
if the first phase, the second phase and the last phase of the converter transformer with the bridge D are respectively the phase A, the phase B and the phase C, the closing time is as follows:
Figure FDA0003619110740000024
in the formula (3), tA、tB、tCThe closing time of the A phase, the B phase and the C phase of the converter transformer of the Y bridge and the D bridge is respectively.
CN202110183561.XA 2021-02-08 2021-02-08 Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation Active CN112968461B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110183561.XA CN112968461B (en) 2021-02-08 2021-02-08 Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110183561.XA CN112968461B (en) 2021-02-08 2021-02-08 Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation

Publications (2)

Publication Number Publication Date
CN112968461A CN112968461A (en) 2021-06-15
CN112968461B true CN112968461B (en) 2022-06-28

Family

ID=76284796

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110183561.XA Active CN112968461B (en) 2021-02-08 2021-02-08 Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation

Country Status (1)

Country Link
CN (1) CN112968461B (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3829192B2 (en) * 2002-09-17 2006-10-04 国立大学法人島根大学 Inrush current suppression method
CN102156216B (en) * 2011-03-17 2013-07-03 清华大学 Method for discriminating magneting inrush current of direct current transmission converter transformer
CN107465168A (en) * 2017-07-27 2017-12-12 国家电网公司运行分公司宜宾管理处 A kind of synchronizing calculation method for suppressing the change of current and becoming the splitting or integrating lock delay of excitation surge current
CN107846004B (en) * 2017-09-30 2019-06-04 全球能源互联网研究院有限公司 Inrush current and the comprehensive suppressing method of transformer excitation flow and realization device
CN110277766B (en) * 2019-07-16 2021-06-29 西华大学 Three-phase linkage circuit breaker magnetizing inrush current suppression method based on switching-on and switching-off control

Also Published As

Publication number Publication date
CN112968461A (en) 2021-06-15

Similar Documents

Publication Publication Date Title
Wang et al. Efficient grounding for modular multilevel HVDC converters (MMC) on the AC side
Sybille et al. Transformer saturation effects on EHV system overvoltages
CN107302216B (en) YNd11 type three-phase transformers drop excitation surge current suppressing method
CN108808719B (en) Predictive constant turn-off angle control method
CN101105517A (en) Gamma/ transformer triangle winding circumfluence algorithm method and device
CN107979080B (en) Method and device for determining rated voltage of lightning arrester along half-wavelength power transmission line
Bi et al. Correlation analysis of waveforms in non-saturation zone based method to identify the magnetizing inrush in transformer
CN110544931A (en) earth fault current compensation system and method for self-generating power phase power supply
CN110441658A (en) A kind of high voltage direct current commutation failure method of discrimination considering DC current variation
CN107785884A (en) A kind of more level active compensation devices of three-phase four-arm and control method
CN102882185B (en) Comprehensive relay protection method for single element zero sequence transverse differential current of large generator
CN105807137A (en) Grounding transformer impedance determining method
CN107482600B (en) Yyn0 type three-phase group formula transformer drops excitation surge current suppressing method
CN112968461B (en) Converter transformer phase selection closing excitation inrush current suppression method based on bias simulation
Ahfock et al. DC magnetisation of transformers
CN109375047B (en) System and method for testing double-end asynchronous polarity of high-voltage transmission line
CN107785915A (en) A kind of more level active compensation devices of front-end power and control method
CN113381432B (en) Method for evaluating influence of synchronous phase modulator fault on extra-high voltage direct current transmission
CN112562965B (en) Pre-magnetizing method for serially connecting small-capacity transformer on marine nuclear power platform
Li et al. Research on effects of transformer DC bias on negative sequence protection
CN104459578B (en) The remanent magnetism method of estimation of Yyn0 type three-phase group formula transformator non-faulting tripping operations
Cao et al. The engineering practical calculation method of circulating current in YD-connected Transformer
Wan et al. Mal-operation Phenomenon of Converter Transformer and Lead Wire Differential Protection during the Energization of" 12-Pulse" Converter Transformer Group
Rioual et al. Field application of a synchronous controller based on the measurement of residual fluxes for the energization of a step-up transformer
Ying et al. Influence of HVDC Reactive Power Compensation Modeling Method on Short-Circuit Current Calculation

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant