CN112952884A - Correction method for interaction factors of multi-feed-in direct current transmission system - Google Patents
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Abstract
The invention provides a method for correcting interaction factors of a multi-feed-in direct current transmission system, which comprises the following steps: according to the control mode of the direct current system, calculating the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus; calculating a correlation coefficient according to the self-impedance amplitude of the converter bus i, the self-impedance angle of the converter bus i, the power of the direct current system j and the mutual impedance amplitude between the converter bus i and the converter bus j; calculating a correction coefficient according to the correlation coefficient, the sensitivity, the self-impedance amplitude of the current conversion bus i and the self-impedance amplitude of the current conversion bus j by using the transimpedance amplitude; calculating a multi-feed interaction factor before correction according to the self-impedance amplitude and the mutual impedance amplitude of the current conversion bus i; and correcting the multi-feed-in interaction factor before correction by adopting a correction coefficient to obtain the corrected multi-feed-in interaction factor. The method can predict the influence of the power grid structure, the operation change and the power grid fault on the interaction factor of the multi-feed-in direct current transmission system.
Description
Technical Field
The invention relates to the technical field of alternating current and direct current interconnected power grids, high-voltage direct current transmission and alternating current and direct current interaction, in particular to a method for correcting interaction factors of a multi-feed-in direct current transmission system.
Background
A plurality of high-voltage direct-current transmission projects are put into operation in China, a multi-direct-current feed-in alternating-current and direct-current interconnected power grid framework is formed in load centers such as east China and south China, and interaction among multiple high-voltage direct-current transmission systems and interaction among direct-current systems and alternating-current systems in the system is more obvious. Research shows that interaction among multiple feed-in direct current transmission systems has great influence on steady-state and dynamic characteristics of the whole alternating current and direct current power grid.
The research working group of the international large power grid conference organization Multi-feed direct-current transmission system provides quantitative indexes for evaluating Interaction between the Multi-feed direct-current transmission systems, namely Multi-feed Interaction factors (MIIF). The MIIF index is calculated as follows:
when the direct current transmission system to be examined runs at rated direct current power, a parallel reactive power branch (generally adopting an inductance branch) is put into a converter bus i of an inverter station to cause step change drop (represented by delta Vi) of about 1% of the voltage of the converter bus, and the voltage change percentage delta Vj of the converter bus j of other inverter stations is detected, so that the calculation formula of an interaction factor MIIFji of the inverter station i to the inverter station j is as follows:
in the formula ZijIs the transfer impedance amplitude, Z, between converter bus i and converter bus jiiIs the self-impedance magnitude of the commutation bus i.
The calculation method is simple and visual, but MIIF obtained by the method is an experimental index, and the index is only suitable for a power grid planning and designing stage and is applied to power grid dispatching operation and needs to be corrected.
Disclosure of Invention
The invention aims to provide a method for correcting interaction factors of a multi-feed-in direct-current power transmission system, aiming at the defects of the prior art, which can predict the influence of the structure, operation change and power grid faults of a power grid on the interaction factors of the multi-feed-in direct-current power transmission system and can be applied to actual power grid dispatching operation.
In a first aspect, an embodiment of the present invention provides a method for correcting an interaction factor of a multi-feed-in direct current power transmission system, including:
according to the control mode of the direct current system, calculating the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus;
calculating a correlation coefficient according to the self-impedance amplitude of the converter bus i, the self-impedance angle of the converter bus i, the power of the direct current system j and the mutual impedance amplitude between the converter bus i and the converter bus j;
calculating a correction coefficient according to the related positive coefficient, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus, the self-impedance amplitude of the conversion bus i, the self-impedance amplitude of the conversion bus j and the mutual impedance amplitude between the conversion bus i and the conversion bus j;
calculating a multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the self-impedance amplitude of the current conversion bus i and the mutual impedance amplitude between the current conversion bus i and the current conversion bus j;
and correcting the multi-feed-in interaction factor before correction between the direct current system i and the direct current system j by adopting the correction coefficient to obtain the multi-feed-in interaction factor after correction between the direct current system i and the direct current system j.
Further, the calculating a correlation coefficient according to the self-impedance amplitude of the commutation bus i, the self-impedance angle of the commutation bus i, the power of the dc system j, and the mutual impedance amplitude between the commutation bus i and the commutation bus j specifically includes:
calculating the correlation coefficient according to the following formula:
wherein a is a correlation coefficient, ZiiFor the self-impedance amplitude, theta, of the commutation bus iiiImpedance angle, P, for self-impedance of converter bus idiPower, P, of the DC system idjPower, Z, of the DC system jijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
Further, the calculating a correction coefficient according to the related positive coefficient, the sensitivity of the converter of the dc system i to absorb reactive power to the voltage of the converting bus, the self-impedance amplitude of the converting bus i, the self-impedance amplitude of the converting bus j, and the transimpedance amplitude between the converting bus i and the converting bus j specifically includes:
calculating the correction factor according to the following formula:
wherein k is a correction coefficient, a is a correlation coefficient, QdiFor absorbing reactive power of the converter, UiFor converting the voltage, dQ, of bus idi/dUiSensitivity Z for absorbing reactive power for I converter of direct current system to voltage of conversion busiiFor the self-impedance amplitude, Z, of the converter bus ijjFor the self-impedance amplitude, Z, of the commutation bus jijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
Further, the calculating a multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the self-impedance amplitude of the commutation bus i and the mutual impedance amplitude between the commutation bus i and the commutation bus j specifically includes:
calculating the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
wherein Z isiiFor the self-impedance amplitude, Z, of the converter bus iijFor the mutual impedance amplitude between the commutation bus i and the commutation bus j
Further, the correcting the multi-feed interaction factor before correction between the dc system i and the dc system j by using the correction coefficient to obtain the corrected multi-feed interaction factor between the dc system i and the dc system j specifically includes:
correcting the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
MIIFji＝k·MIIF'ji
wherein k is a correction coefficient, MIIF'jiShowing the multi-feed interaction factor before correction between the direct current system i and the direct current system j.
Further, the calculating the sensitivity of the i converter of the direct current system to the voltage of the conversion bus for absorbing reactive power according to the control mode of the direct current system specifically comprises:
when the direct current system is under the control of constant current/constant extinction angle, the sensitivity of the current converter of the direct current system i for absorbing reactive power to the voltage of a current conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients.
Further, the calculating the sensitivity of the i converter of the direct current system to the voltage of the conversion bus for absorbing reactive power according to the control mode of the direct current system specifically comprises:
when the direct current system is under the control of constant power/constant extinction angle, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients; pdriDelivering power to a rectification station; r1Resistance of the direct current circuit; dmIs a corresponding equivalent resistance.
Further, the calculating the sensitivity of the i converter of the direct current system to the voltage of the conversion bus for absorbing reactive power according to the control mode of the direct current system specifically comprises:
when the direct current system is under constant direct current voltage/constant current control, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; u shapedriFor rectifying the side DC voltage, IdiIs direct current; pdiThe power of a direct current system i; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; kmAre the corresponding coefficients; r1Is the resistance of the dc line.
Further, the method for correcting the interaction factor of the multi-infeed direct-current transmission system further includes:
when the grid structure is changed due to a fault or disturbance, the corrected multi-feed interaction factor is recalculated according to the changed grid structure.
Further, the method for correcting the interaction factor of the multi-infeed direct-current transmission system further includes:
and when the direct current control mode is switched due to faults or disturbance, recalculating the corrected multi-feed-in interaction factor according to the switched direct current control mode.
The method for correcting the interaction factor of the multi-feed-in direct-current transmission system provided by the embodiment of the invention considers equivalent parameters of a direct-current control mode, direct-current system capacity and a receiving end system, so that the influence of a power grid structure, operation change and power grid faults on the interaction factor of the multi-feed-in direct-current transmission system can be predicted, and the method can be applied to actual power grid dispatching operation. In addition, the method for correcting the interaction factor of the multi-feed-in direct-current power transmission system is simple, and therefore the calculation speed is high.
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In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a flowchart of a method for correcting an interaction factor of a multi-feed dc power transmission system according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a doubly-fed ac/dc system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be understood that the step numbers used herein are for convenience of description only and are not intended as limitations on the order in which the steps are performed.
It is to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The terms "comprises" and "comprising" indicate the presence of the described features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The term "and/or" refers to and includes any and all possible combinations of one or more of the associated listed items.
Example 1:
the embodiment of the invention provides a method for correcting interaction factors of a multi-feed-in direct current transmission system, which comprises the following steps:
and S1, calculating the sensitivity of the I converter of the direct current system to the voltage of the conversion bus for absorbing reactive power according to the control mode of the direct current system.
And S2, calculating a correlation coefficient according to the self-impedance amplitude of the converter bus i, the impedance angle of the self-impedance of the converter bus i, the power of the direct current system j and the mutual impedance amplitude between the converter bus i and the converter bus j.
And S3, calculating a correction coefficient according to the related positive coefficient, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus, the self-impedance amplitude of the conversion bus i, the self-impedance amplitude of the conversion bus j and the mutual impedance amplitude between the conversion bus i and the conversion bus j.
S4, calculating a multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the self-impedance amplitude of the converter bus i and the mutual impedance amplitude between the converter bus i and the converter bus j;
and S5, correcting the multi-feed interaction factor before correction between the direct current system i and the direct current system j by using the correction coefficient to obtain the corrected multi-feed interaction factor between the direct current system i and the direct current system j.
The method for correcting the interaction factor of the multi-feed-in direct-current transmission system provided by the embodiment of the invention considers equivalent parameters of a direct-current control mode, direct-current system capacity and a receiving end system, so that the influence of a power grid structure, operation change and power grid faults on the interaction factor of the multi-feed-in direct-current transmission system can be predicted, and the method can be applied to actual power grid dispatching operation. In addition, the method for correcting the interaction factor of the multi-feed-in direct-current power transmission system is simple, and therefore the calculation speed is high.
As an example of the embodiment of the present invention, the calculating a correlation coefficient according to a self-impedance amplitude of the converter bus i, an impedance angle of the self-impedance of the converter bus i, a power of the direct current system j, and a transimpedance amplitude between the converter bus i and the converter bus j specifically includes:
calculating the correlation coefficient according to the following formula:
wherein a is a correlation coefficient, ZiiFor the self-impedance amplitude, theta, of the commutation bus iiiImpedance angle, P, for self-impedance of converter bus idiPower, P, of the DC system idjPower, Z, of the DC system jijFor the mutual impedance amplitude between the commutation bus i and the commutation bus j
As an example of the embodiment of the present invention, the calculating a correction coefficient according to the related positive coefficient, the sensitivity of the converter of the dc system i to the voltage of the converting bus for absorbing reactive power, the self-impedance amplitude of the converting bus i, the self-impedance amplitude of the converting bus j, and the transimpedance amplitude between the converting bus i and the converting bus j specifically includes:
calculating the correction factor according to the following formula:
wherein k is a correction coefficient, a is a correlation coefficient, QdiFor absorbing reactive power of the converter, UiFor converting the voltage, dQ, of bus idi/dUiSensitivity Z for absorbing reactive power for I converter of direct current system to voltage of conversion busiiFor the self-impedance amplitude, Z, of the converter bus ijjFor the self-impedance amplitude, Z, of the commutation bus jijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
As an example of the embodiment of the present invention, the calculating, according to the self-impedance amplitude of the commutation bus i and the mutual impedance amplitude between the commutation bus i and the commutation bus j, a multi-feed interaction factor before correction between the direct current system i and the direct current system j includes:
calculating the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
wherein Z isiiFor the self-impedance amplitude, Z, of the converter bus iijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
As an example of the embodiment of the present invention, the modifying coefficient is used to modify the multi-feed interaction factor before modification between the dc system i and the dc system j, so as to obtain the modified multi-feed interaction factor between the dc system i and the dc system j, and specifically:
correcting the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
MIIFji＝k·MIIF'ji (4)
wherein k is a correction coefficient, MIIF'jiShowing the multi-feed interaction factor before correction between the direct current system i and the direct current system j.
In the above equations (1) to (4), all variables except for the angle are per unit values, the capacity is based on the rated capacity of the dc system i, the dc voltage is based on the dc rated voltage, and the ac voltage is based on the ac rated voltage.
The control mode of the embodiment of the invention comprises constant current/constant arc-quenching angle control, constant power/constant arc-quenching angle control and constant direct current voltage/constant current control. When the direct current system is under constant current/constant extinction angle control, the quasi-steady state equation of the system is as follows:
the direct current and the arc-quenching angle are kept as the instruction values under the control mode of the fixed current/the fixed arc-quenching angle:
the sensitivity of the converter for absorbing reactive power to the voltage of the conversion bus is obtained as follows:
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients.
Therefore, as an example of the embodiment of the present invention, in step S1, the calculating, according to the control mode of the dc system, the sensitivity of the converter of the dc system i absorbing the reactive power to the voltage of the conversion bus specifically includes:
when the direct current system is under the control of constant current/constant extinction angle, the sensitivity of the current converter of the direct current system i for absorbing reactive power to the voltage of the current conversion bus is calculated according to a formula (7).
When the direct current system is under the control of constant power/constant extinction angle, the quasi-steady state equation of the system is as follows:
under the control mode of fixed power/fixed arc-quenching angle, the direct current power and the arc-quenching angle are kept as instruction values:
the sensitivity of the converter for absorbing reactive power to the voltage of the conversion bus is obtained as follows:
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients; pdriDelivering power to a rectification station; r1Resistance of the direct current circuit; dmIs a corresponding equivalent resistance.
Therefore, as an example of the embodiment of the present invention, in step S1, the calculating, according to the control mode of the dc system, the sensitivity of the converter of the dc system i absorbing the reactive power to the voltage of the conversion bus specifically includes:
when the direct current system is under the control of constant power/constant extinction angle, the sensitivity of the absorbed reactive power of the converter of the direct current system i to the voltage of the conversion bus is calculated according to a formula (10).
When the direct current system is under constant direct current voltage/constant current control, the quasi-steady state equation of the system is as follows:
under the control mode of constant direct current voltage/constant current, the direct current voltage and the direct current on the rectifying side are kept as the instruction values:
the sensitivity of the converter for absorbing reactive power to the voltage of the conversion bus is obtained as follows:
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; u shapedriFor rectifying the side DC voltage, IdiIs direct current; pdiThe power of a direct current system i; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; kmAre the corresponding coefficients; r1Is the resistance of the dc line.
Therefore, as an example of the embodiment of the present invention, in step S1, the calculating, according to the control mode of the dc system, the sensitivity of the converter of the dc system i absorbing the reactive power to the voltage of the conversion bus specifically includes:
when the direct current system is under constant direct current voltage/constant current control, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus is calculated according to a formula (13).
Based on the formula (1) to the formula (13), the MIFF value can be conveniently calculated or the influence of three factors, namely a direct current control mode, direct current system capacity and receiving end system parameters, on MIIF can be quantitatively researched, and the direction is indicated for improving the interaction influence of the system.
Further, the method for correcting the interaction factor of the multi-feed-in direct-current power transmission system provided by the embodiment of the invention further includes:
when the grid structure is changed due to a fault or disturbance, the corrected multi-feed interaction factor is recalculated according to the changed grid structure.
Specifically, the modified multi-feed interaction factor is recalculated in accordance with steps S1-S5.
Further, the method for correcting the interaction factor of the multi-feed-in direct-current power transmission system provided by the embodiment of the invention further includes:
when the direct current control mode is switched due to a fault or disturbance, recalculating the corrected multi-feed-in interaction factor according to the switched direct current control mode;
specifically, the modified multi-feed interaction factor is recalculated in accordance with steps S1-S5.
Example 2
The embodiment of the present invention further provides a device for correcting interaction factors of a multi-feed-in dc power transmission system, including:
the device comprises a converter reactive power absorption conversion bus voltage sensitivity calculation module, a converter reactive power absorption conversion bus voltage sensitivity calculation module and a control module, wherein the converter reactive power absorption conversion bus voltage sensitivity calculation module is used for calculating the sensitivity of a converter reactive power absorption conversion bus voltage of a direct current system i according to the control mode of the direct current system;
the correlation coefficient calculation module is used for calculating a correlation coefficient according to the self-impedance amplitude of the converter bus i, the self-impedance angle of the converter bus i, the power of the direct current system j and the mutual impedance amplitude between the converter bus i and the converter bus j;
the correction coefficient calculation module is used for calculating a correction coefficient according to the related positive coefficient, the sensitivity of reactive power absorbed by the converter of the direct-current system i to the voltage of the conversion bus, the self-impedance amplitude of the conversion bus i, the self-impedance amplitude of the conversion bus j and the mutual impedance amplitude between the conversion bus i and the conversion bus j;
the multi-feed interaction factor calculation module before correction is used for calculating the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the self-impedance amplitude of the current conversion bus i and the mutual impedance amplitude between the current conversion bus i and the current conversion bus j;
and the correction module is used for correcting the multi-feed-in interaction factor before correction between the direct current system i and the direct current system j by adopting the correction coefficient to obtain the corrected multi-feed-in interaction factor between the direct current system i and the direct current system j.
It should be noted that the correction device for the interaction factor of the multi-feed-in dc power transmission system provided in the embodiment of the present invention corresponds to the correction method for the interaction factor of the multi-feed-in dc power transmission system in the embodiment 1 one to one, and therefore, the description of this embodiment is omitted.
In order to verify the effectiveness of the method for correcting the interaction factor of the multi-feed-in direct-current transmission system provided by the present invention, the double-feed alternating-current and direct-current system shown in fig. 2 is provided in this embodiment, the reactive power compensation device on the converter bus is not counted, and the impedance parameters of the receiving-end system are shown in table 1:
TABLE 1
| Z1 | Z2 | Z3 | |
| Case1 | 0.410 | 0.273 | 0.542 |
| Case2 | 0.307 | 0.307 | 0.375 |
| Case3 | 0.237 | 0.361 | 0.275 |
| Case4 | 0.186 | 0.457 | 0.208 |
Recording node admittance matrixes of receiving end systems in cases 1-cases 4 as Y respectively1，Y2，Y3，Y4：
Recording node impedance matrixes of receiving end systems in cases 1-cases 4 as Z1，Z2，Z3，Z4：
Equivalent impedance parameter Z obtained from node impedance matrix11、Z12、Z22As shown in table 2:
TABLE 2
| Z11 | Z22 | Z12 | |
| Case1 | 0.273 | 0.213 | 0.091 |
| Case2 | 0.212 | 0.212 | 0.095 |
| Case3 | 0.172 | 0.212 | 0.100 |
| Case4 | 0.145 | 0.211 | 0.100 |
MIIF 'calculated from Table 2'jiAs shown in table 3:
TABLE 3
| Case1 | Case2 | Case3 | Case4 | |
| MIIF'ji | 0.427 | 0.448 | 0.472 | 0.474 |
The dc system 1 and the dc system 2 in fig. 2 have the same capacity, the model adopted in the Case1-Case4 calculation example is obtained by expanding the ac system at the inverter side by two CIGRE dc standard test models, and the sensitivity (i.e., dQ) of the dc system absorbing the voltage of the reactive-load commutation bus of the reactive-load compensation device on the commutation bus is calculated in different control modes obtained in step S1d1/dU1) As shown in table 4:
TABLE 4
The calculation formula of the correction coefficient k is as follows:
the correction coefficient k obtained from the data in tables 2 and 4 is shown in table 5:
TABLE 5
Applying a correction formula:
MIIFji＝k·MIIF'ji
the modified multi-feed interaction factors can be obtained from the data in tables 3 and 5. The calculation result obtained by the method is recorded as a 'correction calculation result', and a simulation method defined according to the research working group of the multi-feed-in direct-current transmission system of the international large power grid conference organization is used
The obtained MIIF calculation result is a simulation calculation result. The calculation results of two methods obtained by forming different examples in different control modes for different receiving-end system parameters and the direct current system 1 are shown in table 6:
TABLE 6
The calculation result shows that the error between the method provided by the embodiment and the MIIF simulation calculation method obtained by definition is small, the influence of different control modes on the MIIF value can be effectively reflected, and the calculation result is accurate. The MIIF calculation formula provided by the invention is simple and visual, and the influence of the direct current control mode, the direct current system capacity and the receiving end system equivalent parameters on the MIIF value can be conveniently analyzed.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and can include the processes of the embodiments of the methods described above when the computer program is executed. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (10)
1. A method for correcting interaction factors of a multi-feed-in direct current transmission system comprises the following steps:
according to the control mode of the direct current system, calculating the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus;
calculating a correlation coefficient according to the self-impedance amplitude of the converter bus i, the self-impedance angle of the converter bus i, the power of the direct current system j and the mutual impedance amplitude between the converter bus i and the converter bus j;
calculating a correction coefficient according to the related positive coefficient, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus, the self-impedance amplitude of the conversion bus i, the self-impedance amplitude of the conversion bus j and the mutual impedance amplitude between the conversion bus i and the conversion bus j;
calculating a multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the self-impedance amplitude of the current conversion bus i and the mutual impedance amplitude between the current conversion bus i and the current conversion bus j;
and correcting the multi-feed-in interaction factor before correction between the direct current system i and the direct current system j by adopting the correction coefficient to obtain the multi-feed-in interaction factor after correction between the direct current system i and the direct current system j.
2. The method for correcting the interaction factor of the multi-feed-in direct-current transmission system according to claim 1, wherein the calculating of the correlation coefficient according to the self-impedance amplitude of the converter bus i, the impedance angle of the self-impedance of the converter bus i, the power of the direct-current system j, and the transimpedance amplitude between the converter bus i and the converter bus j specifically comprises:
calculating the correlation coefficient according to the following formula:
wherein a is a correlation coefficient, ZiiFor the self-impedance amplitude, theta, of the commutation bus iiiImpedance angle, P, for self-impedance of converter bus idiPower, P, of the DC system idjPower, Z, of the DC system jijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
3. The method for correcting interaction factors of a multi-feed dc power transmission system according to claim 1, wherein the calculating of the correction factors according to the positive correlation coefficients, the sensitivity of the dc system i converter to reactive power absorption on the commutation bus voltage, the self-impedance amplitude of the commutation bus i, the self-impedance amplitude of the commutation bus j, and the mutual impedance amplitude between the commutation bus i and the commutation bus j specifically comprises:
calculating the correction factor according to the following formula:
wherein k isCorrection coefficient, a is correlation coefficient, QdiFor absorbing reactive power of the converter, UiFor converting the voltage, dQ, of bus idi/dUiSensitivity Z for absorbing reactive power for I converter of direct current system to voltage of conversion busiiFor the self-impedance amplitude, Z, of the converter bus ijjFor the self-impedance amplitude, Z, of the commutation bus jijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
4. The method for correcting the interaction factor of the multi-feed direct-current transmission system according to claim 1, wherein the calculating the multi-feed interaction factor before correction between the direct-current system i and the direct-current system j according to the self-impedance amplitude of the converter bus i and the mutual impedance amplitude between the converter bus i and the converter bus j specifically comprises:
calculating the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
wherein Z isiiFor the self-impedance amplitude, Z, of the converter bus iijIs the magnitude of the transimpedance between commutation bus i and commutation bus j.
5. The method for correcting the interaction factor of the multi-feed direct-current power transmission system according to claim 1, wherein the correcting coefficient is used for correcting the multi-feed interaction factor before correction between the direct-current system i and the direct-current system j to obtain the corrected multi-feed interaction factor between the direct-current system i and the direct-current system j, and specifically comprises:
correcting the multi-feed interaction factor before correction between the direct current system i and the direct current system j according to the following formula:
MIIFji＝k·MIIF'ji
wherein k is a correction coefficient, MIIF'jiRepresenting direct currentAnd the multi-feed interaction factor before correction is between the system i and the direct current system j.
6. The method for correcting interaction factors of a multi-feed direct-current transmission system according to claim 1, wherein the sensitivity of i converters of the direct-current system for absorbing reactive power to the voltage of a conversion bus is calculated according to the control mode of the direct-current system, and specifically:
when the direct current system is under the control of constant current/constant extinction angle, the sensitivity of the current converter of the direct current system i for absorbing reactive power to the voltage of a current conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer;Bthe number of the six-pulse current-changing bridges is; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients.
7. The method for correcting interaction factors of a multi-feed direct-current transmission system according to claim 1, wherein the sensitivity of i converters of the direct-current system for absorbing reactive power to the voltage of a conversion bus is calculated according to the control mode of the direct-current system, and specifically:
when the direct current system is under the control of constant power/constant extinction angle, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; i isdiIs direct current; pdiThe power of a direct current system i; gamma rayiThe arc extinguishing angle of the inversion side is adopted; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; xiIs a single bridge commutation reactance; kmAre the corresponding coefficients; pdriDelivering power to a rectification station; r1Resistance of the direct current circuit; dmIs a corresponding equivalent resistance.
8. The method for correcting interaction factors of a multi-feed direct-current transmission system according to claim 1, wherein the sensitivity of i converters of the direct-current system for absorbing reactive power to the voltage of a conversion bus is calculated according to the control mode of the direct-current system, and specifically:
when the direct current system is under constant direct current voltage/constant current control, the sensitivity of the converter of the direct current system i for absorbing reactive power to the voltage of the conversion bus is calculated according to the following formula:
wherein the content of the first and second substances,
wherein, Ud0iThe voltage is the no-load voltage of the direct current side of the inverter station; u shapediThe direct current voltage of the inverter station is obtained; u shapeiIs the voltage of the commutation bus i; u shapedriFor rectifying the side DC voltage, IdiIs direct current; pdiWork of DC system iRate; t isiIs the transformation ratio of the converter transformer; b is the number of six-pulse current-changing bridges; kmAre the corresponding coefficients; r1Is the resistance of the dc line.
9. The method for modifying the interaction factor of a multi-infeed direct-current transmission system according to claim 1, further comprising:
when the grid structure is changed due to a fault or disturbance, the corrected multi-feed interaction factor is recalculated according to the changed grid structure.
10. The method for modifying the interaction factor of a multi-infeed direct-current transmission system according to claim 1, further comprising:
and when the direct current control mode is switched due to faults or disturbance, recalculating the corrected multi-feed-in interaction factor according to the switched direct current control mode.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103972900A (en) * | 2014-05-21 | 2014-08-06 | 中国南方电网有限责任公司电网技术研究中心 | Method for determining distribution of reactive compensation devices of multi-feed direct current transmission system based on voltage control sensitive factors |
| CN104167726A (en) * | 2014-07-07 | 2014-11-26 | 中国南方电网有限责任公司电网技术研究中心 | Calculation method of single-phase multi-feed-in interaction effect factor based on impedance matrix |
| CN106786493A (en) * | 2017-02-17 | 2017-05-31 | 云南电网有限责任公司 | A kind of practical calculation method of multi-infeed HVDC interaction factor |
| CN108233400A (en) * | 2017-12-15 | 2018-06-29 | 华南理工大学 | A kind of more feed-in interaction factor computational methods of meter and hvdc control mode |
-
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- 2021-01-20 CN CN202110077433.7A patent/CN112952884A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103972900A (en) * | 2014-05-21 | 2014-08-06 | 中国南方电网有限责任公司电网技术研究中心 | Method for determining distribution of reactive compensation devices of multi-feed direct current transmission system based on voltage control sensitive factors |
| CN104167726A (en) * | 2014-07-07 | 2014-11-26 | 中国南方电网有限责任公司电网技术研究中心 | Calculation method of single-phase multi-feed-in interaction effect factor based on impedance matrix |
| CN106786493A (en) * | 2017-02-17 | 2017-05-31 | 云南电网有限责任公司 | A kind of practical calculation method of multi-infeed HVDC interaction factor |
| CN108233400A (en) * | 2017-12-15 | 2018-06-29 | 华南理工大学 | A kind of more feed-in interaction factor computational methods of meter and hvdc control mode |
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