CN112366689A - Method and system for determining absolute inertia of alternating current power grid - Google Patents
Method and system for determining absolute inertia of alternating current power grid Download PDFInfo
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- CN112366689A CN112366689A CN202011163175.6A CN202011163175A CN112366689A CN 112366689 A CN112366689 A CN 112366689A CN 202011163175 A CN202011163175 A CN 202011163175A CN 112366689 A CN112366689 A CN 112366689A
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- 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
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- 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
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
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Abstract
本发明提供一种确定交流电网绝对惯量的方法和系统。所述方法和系统采集交流电网正常运行时任意一台发电机的惯量和直流输电系统的输送功率，并在设置直流输电系统闭锁故障后，采集暂态仿真程序执行仿真后发电机的机械功率和电磁功率，计算交流电网的绝对惯量。所述确定交流电网绝对惯量的方法和系统与现有技术相比，不需要大量读取暂态仿真数据，也不需要对各机组惯量进行求和就能快速计算交流电网的绝对惯量，而且采用本发明确定的交流电网绝对惯量具有足够的准确度，也能适用电力系统的多种运行方式。
The present invention provides a method and system for determining the absolute inertia of an alternating current grid. The method and system collect the inertia of any generator and the transmission power of the DC transmission system when the AC power grid is in normal operation, and after setting the DC transmission system blocking fault, collect the mechanical power of the generator and the generator after the simulation is performed by the transient simulation program. Electromagnetic power, calculating the absolute inertia of the AC grid. Compared with the prior art, the method and system for determining the absolute inertia of the AC power grid can quickly calculate the absolute inertia of the AC power grid without reading a large amount of transient simulation data or summing the inertia of each unit. The absolute inertia of the AC power grid determined by the invention has sufficient accuracy, and can also be applied to various operation modes of the power system.
Description
Technical Field
The present invention relates to the field of power simulation, and more particularly, to a method and system for determining the absolute inertia of an ac power grid.
Background
The traditional transient simulation of the power system has great success in the simulation and analysis work of the power system, the numerical solution obtained in the simulation calculation can accurately reflect the operation state of the power system and the transition process after the fault, and meanwhile, the continuous tide, static safety analysis and other mathematical tools developed based on the transient simulation and other technical tools greatly improve the safe and stable operation capability and analysis level of the power system.
Meanwhile, a method and a tool for fast calculation are still lacked in the calculation of the absolute inertia of the alternating current power grid, and the method and the tool are mainly embodied in the following three aspects:
(1) if a pure method of manually counting and accumulating the inertia of the unit is adopted, the calculation speed is extremely low, negligence or omission possibly occurs in the calculation process, and great manpower is required to be invested to recheck the calculation result.
(2) If the unit inertia information in the transient simulation data is directly read by adopting programming languages such as Python and the like, because the types of unit models supported by the current mainstream transient simulation program are continuously abundant, the computer program cannot read the inertia information in various novel unit models.
(3) If power shortage is constructed in transient simulation, the absolute inertia of the alternating current power grid is indirectly estimated through the frequency drop information (particularly the change rate of the frequency of the alternating current power grid to time) of the alternating current power grid, and although the complicated operation of directly reading transient simulation data is avoided, the calculation result of the method is greatly interfered by the primary frequency modulation action of the unit.
Therefore, a technology is needed, which can not only calculate the absolute inertia of the alternating current power grid in an express way, but also ensure the accuracy of calculation.
Disclosure of Invention
In order to solve the technical problems of low speed and low accuracy of calculating the absolute inertia of the alternating current power grid in the prior art, the invention provides a method for determining the absolute inertia of the alternating current power grid, which comprises the following steps:
one generator G is selected randomly in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
The transient simulation program executes simulation according to preset faults and sets simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1；
According to said direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
Further, one generator G is arbitrarily selected in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
The method also comprises the following steps:
DC transmission system DC for setting AC network in simulation1A latch-up failure;
setting the transient simulation program to the DC power transmission system DC1Time t of latching fault execution simulation1。
Further, the transient simulation program is DC-coupled to the DC power transmission system1Time t of latching fault execution simulation1It was 20 seconds.
Further, the transient simulation program is a PSD-BPA program.
Further, according to the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
according to another aspect of the invention, there is provided a system for determining the absolute inertia of an ac power grid, the system comprising:
a data acquisition unit for optionally selecting one generator G in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
A simulation execution unit for executing the simulation by the transient simulation program according to the preset fault and at the set simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1；
A result output unit for DC-dependent of the DC power transmission system1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
Further, the system comprises a parameter setting unit for setting a DC transmission system DC of the ac grid occurring in the simulation1Blocking a fault, and setting the transient simulation program to the DC transmission system DC1Time t of latching fault execution simulation1。
Further, the transient simulation program set by the parameter setting unit is used for DC of the direct current transmission system1Time t of latching fault execution simulation1It was 20 seconds.
Further, the transient simulation program applied by the system is a PSD-BPA program.
Further, a result output unit is in accordance with the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
the method and the system for determining the absolute inertia of the alternating current power grid, provided by the technical scheme of the invention, collect the inertia of any generator and the transmission power of the direct current power transmission system when the alternating current power grid normally operates, collect the mechanical power and the electromagnetic power of the generator after a transient simulation program executes simulation after the locking fault of the direct current power transmission system is set, and calculate the absolute inertia of the alternating current power grid. Compared with the prior art, the method and the system for determining the absolute inertia of the alternating current power grid can quickly calculate the absolute inertia of the alternating current power grid without reading a large amount of transient simulation data and summing the inertia of each unit, and the absolute inertia of the alternating current power grid determined by the method and the system have enough accuracy and can also be suitable for various operation modes of a power system.
Drawings
A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
FIG. 1 is a flow chart of a method of determining the absolute inertia of an AC power grid in accordance with a preferred embodiment of the present invention;
FIG. 2 is a graph illustrating the mechanical power variation of a generator during transient simulation according to a preferred embodiment of the present invention;
FIG. 3 is a graph illustrating electromagnetic power variation of a generator during transient simulation according to a preferred embodiment of the present invention;
fig. 4 is a schematic diagram of a system for determining the absolute inertia of an ac power grid according to a preferred embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flow chart of a method of determining the absolute inertia of an ac power grid according to a preferred embodiment of the present invention. As shown in fig. 1, the method 100 for determining the absolute inertia of an ac power grid according to the preferred embodiment starts with step 101.
In step 101, a direct current transmission system DC of an alternating current grid occurring in a simulation is set1Blocking a fault, and setting the transient simulation program to the DC transmission system DC1Time t of latching fault execution simulation1。
In step 102, a generator G is optionally selected in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
In step 103, the transient simulation program executes simulation according to the preset fault and sets the simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1。
In step 104, DC is transmitted according to the DC transmission system1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
Preferably, the transient simulation program is DC-to the direct current transmission system1Time t of latching fault execution simulation1It was 20 seconds.
Preferably, the transient simulation program is a PSD-BPA program.
Preferably, according to the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
in the embodiment, a power grid in a certain region of China is taken as a test object. Collecting the transmission power of a DC power transmission system in the peak load operation mode
7475 megawatts, a certain generator G1Inertia J13459.3 megawatts per second. Setting a blocking fault for a selected DC power transmission system in the AC power grid, and setting a simulation execution time t1After 20 seconds, transient simulation was performed.
FIG. 2 is a mechanical power curve of a generator during transient simulation according to a preferred embodiment of the present invention. As shown in FIG. 2, as the transient simulation is performed, the generator G is selected1Is kept constant, and when the simulation is executed for 20 seconds, the generator G is acquired1The mechanical power of (2) is 661.32 megawatts.
FIG. 3 is a generator electromagnetic power curve when transient simulation is performed according to the preferred embodiment of the present invention. As shown in FIG. 3, as the transient simulation is performed, the generator G is selected1After the electromagnetic power fluctuates, when the simulation is executed for 20 seconds, the electromagnetic power is basically balanced, and the generator G is acquired1The electromagnetic power of (a) is 675.75 megawatts.
Substituting the formula for calculating the absolute inertia of the alternating current power grid into the acquired data to obtain the absolute inertia JsysIs composed of
Megawatt seconds, which is very close to the true value of 1810133 megawatt seconds.
Fig. 4 is a schematic diagram of a system for determining the absolute inertia of an ac power grid according to a preferred embodiment of the present invention. As shown in fig. 4, the system 400 for determining the absolute inertia of the ac power grid according to the preferred embodiment includes:
a parameter setting unit 401 for setting a direct current transmission system DC of the alternating current grid occurring in the simulation1Blocking a fault, and setting the transient simulation program to the DC transmission system DC1Time t of latching fault execution simulation1。
A data acquisition unit 402 for optionally selecting one generator G in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
A simulation execution unit 403 for executing the simulation by the transient simulation program according to the preset fault and at the set simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1；
A result output unit 404 for outputting a result according to the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
Preferably, the transient simulation program set by the parameter setting unit is used for the DC transmission system DC1Time t of latching fault execution simulation1It was 20 seconds.
Further, the transient simulation program applied by the system is a PSD-BPA program.
Further, a result output unit is in accordance with the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
the method for protecting the direct current transmission line by the direct current transmission line protection system based on the single-ended differential current accumulation amount has the same steps as the direct current transmission line protection criterion, achieves the same technical effect, and is not repeated herein.
The invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. A method of determining the absolute inertia of an ac power grid, the method comprising:
one generator G is selected randomly in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
The transient simulation program executes simulation according to preset faults and sets simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1；
According to said direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
2. The method of claim 1, wherein one generator G is arbitrarily selected in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
The method also comprises the following steps:
DC transmission system DC for setting AC network in simulation1A latch-up failure;
setting the transient simulation program to the DC power transmission system DC1Time t of latching fault execution simulation1。
3. The method according to claim 1, characterized in that the transient simulation program DC the direct current transmission system1Time t of latching fault execution simulation1It was 20 seconds.
4. The method of claim 2, wherein the transient simulation program is a PSD-BPA program.
5. Method according to claim 1, characterized in that according to the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
6. a system for determining the absolute inertia of an ac power grid, the system comprising:
a data acquisition unit for optionally selecting one generator G in the transient simulation program1And a direct current transmission system DC1And reading the generator G1Inertia J of1And a direct current transmission system DC1Transmitted power of
A simulation execution unit for executing the simulation by the transient simulation program according to the preset fault and at the set simulation time t1At the end, reading generator G1Electromagnetic power P ofe1And mechanical power Pm1；
A result output unit for DC-dependent of the DC power transmission system1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsys。
7. System according to claim 6, characterized in that the system further comprises a parameter setting unit for setting the DC transmission system DC of the AC grid as it appears in the simulation1Blocking a fault, and setting the transient simulation program to the DC transmission system DC1Time t of latching fault execution simulation1。
8. The system according to claim 6, characterized in that the transient simulation program set by the parameter setting unit is DC to the DC power transmission system1Time t of latching fault execution simulation1It was 20 seconds.
9. The system of claim 7, wherein the transient simulation program applied by the system is a PSD-BPA program.
10. The system according to claim 6, characterized in that the result output unit is based on the direct current transmission system DC1Transmitted power of
Generator G1Inertia J of1Electromagnetic power Pe1And mechanical power Pm1Calculating the absolute inertia J of an AC power gridsysThe calculation formula is as follows:
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- 2020-10-27 CN CN202011163175.6A patent/CN112366689B/en active Active
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| WO2014117582A1 (en) * | 2013-02-04 | 2014-08-07 | 国家电网公司 | Real-time emergency control method of relative kinetic energy-based power system transient stability |
| CN106208030A (en) * | 2015-05-06 | 2016-12-07 | 华北电力大学（保定） | A kind of virtual inertia control system of independent wind storage direct-current grid |
| CN109494765A (en) * | 2018-11-13 | 2019-03-19 | 北京交通大学 | Alternating current-direct current combined hybrid system transient stability control method based on EEAC |
| CN109742785A (en) * | 2019-01-04 | 2019-05-10 | 华南理工大学 | A method for evaluating the inertial control capability of generators in a multi-circuit VSC-HVDC DC system |
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