CN108565858B - Reliability evaluation method for hybrid alternating current-direct current power distribution network containing flexible transformer substation - Google Patents

Reliability evaluation method for hybrid alternating current-direct current power distribution network containing flexible transformer substation Download PDF

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CN108565858B
CN108565858B CN201810466643.3A CN201810466643A CN108565858B CN 108565858 B CN108565858 B CN 108565858B CN 201810466643 A CN201810466643 A CN 201810466643A CN 108565858 B CN108565858 B CN 108565858B
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CN108565858A (en
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周晖
胡顺威
周方泽
刘桢
从黎
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Beijing Jiaotong University
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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
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
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    • G06F30/00—Computer-aided design [CAD]
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    • G06F30/398—Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM]
    • 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
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    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract

The embodiment of the invention provides a method for evaluating the reliability of a hybrid alternating current-direct current power distribution network comprising a flexible substation. The method comprises the following steps: acquiring network topology and element reliability parameter values of a power distribution network, and determining reliability parameters of a Distributed Generation (DG); constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network; establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to a load according to whether the distributed power supply DG can meet the load requirement independently; according to the minimum cut set theory, utilizing a multi-power supply fault tree or a single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network; and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network. The method solves the problem of reliability evaluation of the power distribution network under the condition that the power electronic transformer equipment which is not commercially operated is applied to the flexible transformer substation, and provides technical support for the research and planning design of the flexible transformer substation project.

Description

Reliability evaluation method for hybrid alternating current-direct current power distribution network containing flexible transformer substation
Technical Field
The invention relates to the technical field of power distribution networks, in particular to a reliability evaluation method for a hybrid alternating current-direct current power distribution network comprising a flexible substation.
Background
With the maturity of energy development and utilization technology, the proportion of clean energy such as wind power, photovoltaic and the like on the power supply side in the power supply structure is gradually increased. Meanwhile, the types and the power utilization modes of loads on the power utilization side are changed, for example, the number of direct current loads such as computers and data centers is increased, and a charging and discharging bidirectional load formed by the electric automobile industry driven by green traffic appears. In order to cope with the fluctuation of generated output caused by the instability of natural resources such as wind and light and reduce the harmonic wave generated by the direct current load on the alternating current power grid, an energy storage device, a filtering device, a reactive power compensation device and the like are additionally arranged on the power grid. The problems that arise from this are: the number of AC/DC conversion devices in the power grid is increased, including DC/AC or AC/DC conversion devices with different voltage levels, and new devices such as DG (distributed generation, distributed power supply) and energy storage are added in the power grid, and these devices also have respective output characteristics, which makes the structure of the power distribution network more complex and makes coordination control more difficult. In order to solve the problem, applying power electronic transformers to substations by means of the increasingly mature power electronic technology and flexible equipment manufacturing technology thereof is one of the solutions for solving the above complex problems.
The power electronic transformer is an integrated device consisting of a modularized converter and a high-frequency transformer, has multiple functions of flexible power regulation, alternating current-direct current conversion and the like, can be conveniently connected with bidirectional load and energy storage devices such as distributed energy sources and electric vehicle storage batteries, can conveniently regulate and control the operation mode of a power distribution network and other excellent performances, simplifies the structure of the power distribution network, is flexible to control, is convenient for hierarchical control, thereby becoming a novel device which replaces the conventional power transformer in the transformer substation and integrates transformation and flexible control, the transformer substation can not only transform and distribute electric energy, but also control the electrical parameters inside and outside the substation, including voltage, current, power and the like, therefore, the conventional transformer substation is transformed into a flexible transformer substation which meets the control and management needs of the current power grid, and the configuration of the original power distribution network is greatly changed. Under the condition, the reliability analysis of the hybrid alternating current and direct current power distribution network containing the flexible transformer substation becomes very important, and the method can help a power manager to clearly influence the changed weak modules of the power distribution network reliability, so that the refinement of research and management work of related technologies is enhanced, and the power distribution network is guaranteed to have higher design and operation levels.
When the reliability analysis of the power distribution network comprising the flexible substation is carried out, the problems that the power electronic transformer of key equipment in the flexible substation does not enter the commercial operation and lacks reliability operation parameters are solved, and the reliability analysis of the power distribution network in the past is mostly based on the statistical parameter calculation of all operation equipment of the power distribution network and provides services for the operation management of the power distribution network. The reliability analysis of the power distribution network of the power electronic transformer equipment in operation is not seen and reported. In the past, reliability analysis of flexible power equipment such as direct-current transmission converter equipment and the like adopts an element-level reliability theoretical model for analysis and calculation, so that the reliability analysis is over-ideal; in addition, the flexible power equipment has a high voltage level of at least 10kV and above, a complex topology, and thousands of IGBTs (Insulated Gate Bipolar transistors) are arranged inside the flexible power equipment, and the equipment reliability calculated based on a large number of element-level reliability theoretical models is easy to generate a large error and has a large distance from the engineering practice.
Considering that a novel power device such as a power electronic transformer is put into a power grid, in the requirement of reliability evaluation of project research or planning design, a set of method for evaluating the reliability of a hybrid alternating current-direct current power distribution network which can meet engineering requirements and is convenient to calculate is needed to be designed, and the condition that the power electronic transformer device which is not put into operation is contained in a flexible substation is processed.
Disclosure of Invention
The embodiment of the invention provides a method for evaluating the reliability of a hybrid alternating current-direct current power distribution network considering a flexible substation, which aims to solve the problems in the background art.
In order to achieve the purpose, the invention adopts the following technical scheme:
the embodiment of the invention provides a reliability evaluation method for a hybrid alternating current-direct current power distribution network comprising a flexible substation, which is characterized by comprising the following steps:
acquiring network topology and element reliability parameter values of the power distribution network;
determining a reliability parameter of a distributed power supply DG;
constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network;
establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to the load according to whether the distributed power supply DG can meet the load requirement independently;
according to a minimum cut set theory, utilizing the multi-power supply fault tree or the single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network;
and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network.
Preferably, the acquiring the network topology and the element reliability parameter value of the power distribution network includes:
the network topology of the power distribution network comprises: the system comprises a flexible transformer substation, a high-voltage alternating current network, a high-voltage direct current network, a low-voltage alternating current network and a low-voltage direct current network;
the high-voltage alternating current network is connected with a high-voltage alternating current power supply and is connected with the flexible transformer substation through a high-voltage alternating current inlet wire;
the high-voltage direct-current network is connected with a high-voltage direct-current power supply and is connected with the flexible transformer substation through a high-voltage direct-current incoming line;
the low-voltage alternating current network is connected with the flexible transformer substation through a low-voltage alternating current outlet wire and is connected with a low-voltage alternating current load;
the low-voltage direct-current network is connected with the flexible substation through a low-voltage direct-current outlet and is connected with a low-voltage direct-current load.
Preferably, the acquiring the network topology and the element reliability parameter value of the power distribution network further includes:
the element is an element of a power distribution network containing a flexible substation, and comprises the following components: power electronic transformers, circuit breakers, disconnectors, busbars, distribution lines and power transformers, the elements within the flexible substation include but are not limited to: the power electronic transformer, the circuit breaker, the isolating switch and the bus;
the distribution line is an overhead line or a cable;
the circuit breaker includes: direct current circuit breakers and alternating current circuit breakers;
the power electronic transformer includes: the main circuit comprises 5 transformation modules based on internal topology and interfaces: the power electronic transformer comprises a first-stage AC/DC converter, a second-stage DC/AC converter, a third-stage high-frequency transformer, a fourth-stage AC/DC converter and a fifth-stage DC/AC converter, wherein the first-stage AC/DC converter takes high-voltage alternating current as input of the power electronic transformer, and the fifth-stage DC/AC converter outputs low-voltage alternating current for use by an alternating-current load;
the power electronic transformer includes but is not limited to: the device is provided with a direct current port and an alternating current port;
the bus adopts the following steps: single bus, single bus segment, bridge connection, double bus or double bus segment.
Preferably, the acquiring the network topology and the element reliability parameter value of the power distribution network further includes:
the flexible transformer substation and the high-voltage alternating current network, the high-voltage direct current network, the low-voltage alternating current network and the low-voltage direct current network are in a topological mode as follows:
the inlet wire of the flexible transformer substation: the DC power supply in the high-voltage DC network is connected with the incoming line side BUS BUS through the DC breakerHDSaid BUSHDThe other side of the direct current circuit breaker is connected to the high-voltage direct current side of the power electronic transformer through the direct current circuit breaker;
the alternating current power supply in the high-voltage alternating current network is connected with an inlet wire side BUS BUS through the two alternating current circuit breakers respectivelyHA1、BUSHA2Said BUSHA1And said BUSHA2By means of a sectionalising breaker SWBConnected, the BUSHA1Connected to the high voltage AC side of the power electronic transformer via the AC circuit breaker, the BUSHA2Is connected to the high-voltage side of a power transformer through the alternating-current circuit breaker;
the outgoing line of the flexible transformer substation is as follows: the low-voltage direct-current network comprises a direct-current LOAD (LOAD)D11And a bidirectional charging and discharging device LOADD12The LOADD11And said LOADD12The low-voltage direct-current side of the power electronic transformer is connected with the direct-current circuit breaker and the low-voltage direct-current bus in sequence;
sensitive AC LOAD LOAD in the low-voltage AC networkA1The low-voltage alternating-current bus is connected to the low-voltage alternating-current side of the power electronic transformer through the alternating-current circuit breaker and the low-voltage alternating-current bus in sequence;
a normal AC LOAD LOAD in the low voltage AC networkA2Is connected to electricity in turn via the AC circuit breaker and the low-voltage AC busThe low voltage side of the force transformer.
Preferably, the acquiring the network topology and the element reliability parameter value of the power distribution network further includes:
the element reliability parameter values include: failure rate and repair time;
the fault rates and the repair time of the power electronic transformer, the bus, the circuit breaker and the distribution line are obtained by searching according to historical statistical data, and the fault rates of the power electronic transformer, the bus, the circuit breaker and the distribution line are respectively as follows: pT、PBUS、PSW、PLINEThe repair time of the power electronic transformer, the bus, the breaker and the distribution line is respectively as follows: rT、RBUS、RSW、RLINE。
Preferably, the determining the reliability parameter of the distributed power supply DG includes:
setting the reliability parameter of the distributed power supply DG as PDG；
Predetermining installed capacity of distributed power supply DG, and giving fault rate of distributed power supply lambdaDGFault repair time of RDGAccording to the historical operation data of the distributed power supply DG in the region, the annual operation hours is set as TDGAcquiring the output power of the distributed power supply DG, comparing the output power with the load power, and setting the probability and the fault rate of the distributed power supply DG without power output as PDgiI is 1, 2; then P isDGComprises the following steps:
Figure GDA0002984416150000051
8760-24 hours/day × 365 days/year, which refers to the number of hours of a year, in hours (h);
Figure GDA0002984416150000052
RDGtime to failure repair for a DG is a known parameter used to calculate reliability, through historical movement of the DGCounting the line data to obtain;
Figure GDA0002984416150000053
wherein, PDGiThe results of calculation according to the formulas (1) and (2) are shown.
Preferably, the constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network includes:
a current converter and a high-frequency transformer in the power electronic transformer obtain reliability parameters by referring to historical operating data;
determining power supply paths of load points according to the network topology of the power distribution network, further determining the operation mode of a power electronic transformer and the modules of the power electronic transformer in each power supply path, and participating the modules in operation;
the modules are 5 conversion modules of the power electronic transformer PET, and the failure rate of each module is set as PpetjReliability P of the transformation module of said power electronic transformerpetjThe known parameters are obtained by statistics of historical operating data of the transformation module, and the repair time is RpetjAnd calculating the annual fault time, wherein j is 1 … … m, m is 5 m, and m is the number of modules input by the power electronic transformer, so that the fault rate of the power electronic transformer is as follows:
Figure GDA0002984416150000061
preferably, the establishing a multi-power failure tree or a single-power failure tree corresponding to the load according to whether the distributed generation DG can individually meet the load demand includes:
judging whether the distributed power supply DG can independently meet the load requirement, if the reliability parameter of the distributed power supply DG can independently meet the load requirement, establishing a multi-power-supply fault tree corresponding to the load, and if the reliability parameter of the distributed power supply DG cannot independently meet the load requirement, establishing a single-power-supply fault tree corresponding to the load;
defining the system fault as a top event, and recording the system fault as a top event A when the power sent by the DG is greater than or equal to the power required by the load in the power distribution network1Otherwise, it is top event A2. Accordingly, network topology and load point power supply paths under the condition that load requirements can be met or cannot be met independently are analyzed respectively, element faults are generated from top events to bottom events through layer-by-layer analysis according to the fault tree theory, and a fault tree diagram F corresponding to loads is established for each load pointTAk，k＝1，2。
Preferably, according to the minimum cut set theory, the reliability indexes of the loads in the power distribution network are respectively calculated by using the multiple power supply fault tree or the single power supply fault tree, and the reliability indexes include:
according to the minimal cut set theory, obtaining A from the fault tree diagram1、A2Minimal cut sets in two states: a. the11…A1m，A21…A2nWherein A isk＝{Xk1,Xk2,…,XklIs bottom event XklA set of (a);
calculating the load point A according to the formulas (5) and (6)1、A2Annual failure rate in both cases
Figure GDA0002984416150000071
Annual power off time
Figure GDA0002984416150000072
Then weighting according to formulas (7) and (8) to obtain the annual fault rate P of the load pointLOADD11Annual power failure time TLOADD11；
Figure GDA0002984416150000073
Figure GDA0002984416150000074
Figure GDA0002984416150000075
Figure GDA0002984416150000076
Figure GDA0002984416150000077
Wherein alpha is2＝1-α1。
Preferably, the calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network includes:
sequentially calculating the annual fault rate P of S load points in the power distribution networkloadtAnnual power failure time TloadtThen, the overall annual fault rate of the power distribution network is as follows:
Figure GDA0002984416150000078
the whole annual power failure time of the power distribution network is as follows:
Figure GDA0002984416150000079
according to the technical scheme provided by the embodiment of the invention, the reliability parameter of the distributed power supply DG is determined by acquiring the network topology and the element reliability parameter value of the power distribution network; constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network; establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to a load according to whether the distributed power supply DG can meet the load requirement independently; according to the minimum cut set theory, utilizing a multi-power supply fault tree or a single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network; and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network. The method is simple and easy to implement, can meet engineering requirements, can solve the problem of reliability evaluation of the power distribution network under the condition that the power electronic transformer equipment which is not operated commercially is applied to the flexible transformer substation, and provides technical support for the research and planning design of the flexible transformer substation project.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced 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 to obtain other drawings based on these drawings without inventive labor.
Fig. 1 is a processing flow diagram of a method for evaluating reliability of a hybrid ac/dc distribution network including a flexible substation according to an embodiment of the present invention;
fig. 2 is a schematic connection diagram of a hybrid ac/dc distribution network including a flexible substation according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a main circuit of a power electronic transformer for a flexible substation according to an embodiment of the present invention;
fig. 4 is a load point power supply path diagram of a hybrid ac/dc distribution network including a flexible substation according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated 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. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
It will be understood by those skilled in the art that, unless otherwise defined, all 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. It will be further 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 prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
For the convenience of understanding the embodiments of the present invention, the following description will be further explained by taking several specific embodiments as examples in conjunction with the drawings, and the embodiments are not to be construed as limiting the embodiments of the present invention.
Example one
The embodiment of the invention provides a reliability evaluation method for a hybrid alternating current-direct current power distribution network containing a flexible transformer substation, which is used for performing reliability analysis on the power distribution network containing the flexible transformer substation, is simple and feasible and meets engineering requirements.
The processing flow chart of the reliability evaluation method for the hybrid alternating current-direct current power distribution network containing the flexible substation provided by the embodiment of the invention is shown in fig. 1, and the method comprises the following steps:
the method comprises the following steps: and acquiring the network topology and element reliability parameter values of the power distribution network.
The network topology of the power distribution network comprises: flexible transformer substation, high voltage alternating current network, high voltage direct current network, low voltage alternating current network and low voltage direct current network. The high-voltage alternating current network is connected with a high-voltage alternating current power supply and is connected with the flexible transformer substation through a high-voltage alternating current inlet wire; the high-voltage direct-current network is connected with a high-voltage direct-current power supply and is connected with the flexible transformer substation through a high-voltage direct-current incoming line; the low-voltage alternating current network is connected with the flexible substation through a low-voltage alternating current outgoing line and is connected with a low-voltage alternating current load; the low-voltage direct current network is connected with the flexible substation through the low-voltage direct current outgoing line and is connected with a low-voltage direct current load.
The element is an element of the power distribution network with the flexible transformer substation, and comprises a power electronic transformer, a circuit breaker, an isolating switch, a bus, a distribution line and a power transformer. Elements within the flexible substation include, but are not limited to: power electronic transformers, circuit breakers, disconnectors and busbars.
The distribution line may be an overhead line or a cable.
The circuit breaker includes: direct current circuit breakers and alternating current circuit breakers.
The power electronic transformer includes: a main circuit and a control circuit. The main circuit needs to contain 5 transformation modules based on internal topology and interfaces: the power electronic transformer comprises a first-stage AC/DC converter, a second-stage DC/AC converter, a third-stage high-frequency transformer, a fourth-stage AC/DC converter and a fifth-stage DC/AC converter, wherein the first-stage AC/DC converter takes high-voltage alternating current as input of the power electronic transformer, and the fifth-stage DC/AC converter outputs low-voltage alternating current for use by an alternating-current load. Power electronic transformers include, but are not limited to: there is one dc port and one ac port.
The form of the in-station busbar, whether on the high-voltage side or the low-voltage side, may be a single busbar, a single busbar section. Bridging, double bus sectioning, etc. may be chosen for reliability or operational requirements.
Therefore, the flexible substation and the high-voltage alternating current network, the high-voltage direct current network, the low-voltage alternating current network and the low-voltage direct current network are topologically arranged as follows:
(1) inlet wire of flexible transformer substation
A. DC power supply among the high voltage direct current network warp direct current breaker connects inlet wire side bus BUSHD, the opposite side warp of BUSHD direct current breaker connects to the high voltage direct current side of power electronic transformer.
B. The AC power supply in the high-voltage AC network is connected with the incoming line side BUS BUS through the two AC circuit breakers respectivelyHA1、BUSHA2Said BUSHA1And said BUSHA2By means of a sectionalising breaker SWBConnected, the BUSHA1Connected to the high voltage AC side of the power electronic transformer via the AC circuit breaker, the BUSHA2Connected to the high voltage side of the power transformer via said ac circuit breaker. The power transformer refers to a conventional transformer, such as T2 in fig. 4; the power electronic transformer refers to a novel transformer adopting power electronic technology and current transformation technology, such as T1 in fig. 4.
(2) Outgoing line of flexible substation
A. The low-voltage direct-current network comprises a direct-current LOAD (LOAD)D11And a bidirectional charging and discharging device LOADD12The LOADD11And said LOADD12And the low-voltage direct-current side of the power electronic transformer is connected with the low-voltage direct-current side of the power electronic transformer through the direct-current circuit breaker and the low-voltage direct-current bus in sequence.
B. Sensitive AC LOAD LOAD in the low-voltage AC networkA1And the low-voltage alternating current bus is connected to the low-voltage alternating current side of the power electronic transformer through the alternating current breaker and the low-voltage alternating current bus in sequence.
C. A normal AC LOAD LOAD in the low voltage AC networkA2And the low-voltage side of the power transformer is connected with the low-voltage side of the power transformer through the alternating-current circuit breaker and the low-voltage alternating-current bus in sequence.
The element reliability parameter values include: failure rate and repair time.
The fault rates and the repair time of the power electronic transformer, the bus, the circuit breaker and the distribution line are obtained by searching according to historical statistical data, and the fault rates of the power electronic transformer, the bus, the circuit breaker and the distribution line are respectively as follows: pT、PBUS、PSW、PLINEThe repair time of the power electronic transformer, the bus, the breaker and the distribution line is respectively as follows: rT、RBUS、RSW、RLINE. An overhead line is a line used between a connection point and a point in a power distribution network in an overhead manner, and the point can be a substation or a power supply or a load. Considering that there are both overhead lines and cables in the distribution line, the overhead lines can be replaced with the distribution lines.
Step two: a reliability parameter of the distributed power supply DG is determined.
(1) Setting the reliability parameter of the distributed power supply DG as PDG。
(2) Predetermining installed capacity of distributed power supply DG, and giving fault rate of distributed power supply lambdaDGFault repair time of RDGAccording to the historical operation data of the distributed power supply DG in the region, the annual operation hours is set as TDGAcquiring the output power of the distributed power supply DG, comparing the output power with the load power, and setting the probability and the fault rate of the distributed power supply DG without power output as PDGi(i is 1, 2), then PDGComprises the following steps:
Figure GDA0002984416150000121
where parameter 8760 refers to the number of hours of a year, in hours (h).
Figure GDA0002984416150000122
RDGThe time for fault recovery is a known parameter for calculating reliability and can be obtained by statistics of the historical operating conditions of the DG.
Figure GDA0002984416150000123
Wherein, PDGiThe results of calculation according to the formulas (1) and (2) are shown.
Step three: and constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network.
(1) A current converter and a high-frequency transformer in the power electronic transformer obtain reliability parameters by referring to historical operating data.
(2) And determining power supply paths of load points according to the network topology of the power distribution network, further determining the operation mode of the power electronic transformer and the modules of the power electronic transformer in each power supply path, and participating the modules in operation.
In the 5 modules of the power electronic transformer PET, the failure rate of each module is set as PpetAnd the reliability P of the conversion module of the power electronic transformerpetjThe parameters are known, do not need to be solved, and can be obtained by historical operation statistics of the transformation module. The repair time is RpetjSaid repair time RpetjFor solving a calculated annual fault time, where j is 1 … … m, m is 5 m, and m is the number of modules the power electronic transformer is put into), the fault rate of the power electronic transformer is:
Figure GDA0002984416150000131
step four: and establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to the load according to whether the distributed power supply DG can meet the load requirement independently.
Judging whether the distributed power supply DG can independently meet the load requirement, if the reliability parameter of the distributed power supply DG can independently meet the load requirement, establishing a multi-power-supply fault tree corresponding to the load, and if the reliability parameter of the distributed power supply DG cannot independently meet the load requirement, establishing a single-power-supply fault tree corresponding to the load.
Defining the system fault as a top event, and recording the system fault as a top event A when the power sent by the DG is greater than or equal to the power required by the load in the power distribution network1Otherwise, it is recorded as top event A2From which the nets under conditions in which the load demand can or cannot be met individually are analyzed separatelyThe network topology and the load point power supply path are analyzed layer by layer from a top event to a bottom event to be an element fault according to a fault tree theory, and a fault tree graph F corresponding to the load is established for each load pointTAk(k＝1，2)。
Step five: and according to a minimum cut set theory, utilizing the multi-power supply fault tree or the single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network.
According to the minimal cut set theory, obtaining A from the fault tree diagram1、A2Minimal cut sets in two states: a. the11…A1m，A21…A2nWherein A isk＝{Xk1,Xk2,…,XklIs bottom event XklA set of (a);
calculating the load point A according to the formulas (5) and (6)1、A2Annual failure rate in both cases
Figure GDA0002984416150000132
Annual power off time
Figure GDA0002984416150000133
Then weighting according to formulas (7) and (8) to obtain the annual fault rate P of the load pointLOADD11Annual power failure time TLOADD11；
Figure GDA0002984416150000134
Figure GDA0002984416150000141
Figure GDA0002984416150000142
Figure GDA0002984416150000143
Figure GDA0002984416150000144
Figure GDA0002984416150000145
Wherein alpha is2＝1-α1。
Step six: and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network.
According to the method in the step five, the annual fault rate P of S load points in the power distribution network is calculated in sequenceloadtAnnual power failure time TloadtThen, the overall annual fault rate of the power distribution network is as follows:
Figure GDA0002984416150000146
the whole annual power failure time of the power distribution network is as follows:
Figure GDA0002984416150000147
example two
The embodiment provides a method for evaluating reliability of a hybrid alternating current/direct current power distribution network with a flexible substation, the specific implementation method is shown in fig. 1, the specific implementation background is the hybrid alternating current/direct current power distribution network with the flexible substation, the schematic diagram is shown in fig. 2, and the power distribution network comprises the flexible substation, a high-voltage alternating current network, a high-voltage direct current network, a low-voltage alternating current network and a low-voltage direct current network.
No matter the high-voltage alternating current network or the high-voltage direct current network or the low-voltage alternating current network or the low-voltage direct current network, the wiring mode is determined according to the actual situation and can be respectively connected with: the high-voltage alternating current power supply, the high-voltage direct current power supply, the low-voltage alternating current load and the low-voltage direct current load. The power supply in fig. 2 is an equivalent power supply, and for a direct current power supply, the power supply can be a wind, electricity or photovoltaic distributed power supply; the load is an equivalent load, and for the direct current load, the load can be a direct current load such as a computer, a data center and the like, or a bidirectional charge and discharge load; the ac loads are classified into a custom power and a conventional ac load, wherein the custom power refers to a requirement for a special requirement for an ac output, such as a harmonic component. The network wiring is simply adopted: high-voltage alternating current incoming lines, high-voltage direct current incoming lines, low-voltage alternating current outgoing lines and low-voltage direct current outgoing lines.
The flexible substation at least contains one PET (power electronic transformer), and the PET can be in a four-port mode or in other modes such as a three-port mode according to the field requirement, but at least one direct current port and one alternating current port ensure that the network has alternating current and direct current. The further transformer may be a conventional power transformer. According to the actual needs and the design principle of the transformer substation, the flexible transformer substation can be set into a single transformer type.
A primary system in a flexible substation refers to the organic integration of a plurality of power devices for completing power transmission and transformation for the substation; typically including transformers, circuit breakers, disconnectors, busbars, etc., which are not shown in fig. 2 for simplicity. Wherein, the circuit breaker divide into according to its position and effect: alternating current circuit breakers and direct current circuit breakers. Wherein PET both sides are set up the circuit breaker, decide according to the design requirement, and PET is power electronics device in essence, has the function of circuit breaker. The bus in the station, whether on the high-voltage side or the low-voltage side, can be a single bus or a single bus segment; bridging, double bus sectioning, etc. may be chosen for reliability or operational requirements.
In fig. 2, the dashed line indicates a flexible substation, AG1，AG2A high-voltage alternating-current power supply is shown, and a high-voltage distributed power supply is shown by DG; LOADA1Representing a custom AC LOAD, LOADA1Representing a conventional AC LOAD, LOADD1Unidirectional DC LOAD, LOAD, as indicatedD2The shown bidirectional charging and discharging direct current load; LINEHA1、LINEHA2Denoted high side ac inlet LINE, LINEHDShown is a high side DC inlet LINE, LINELA1、LINELA2Showing the low-side ac outlet LINE, LINELD1、LINELD2A low side dc out line is shown. T isPETDenoted is a power electronic transformer, TCOMShown is a conventional power transformer, BUSHA1，BUSHA2Shown is a high voltage AC BUS, BUSHD1Denoted high voltage DC BUS, BUSLA1，BUSLA2Respectively indicated low-voltage AC BUS, BUSLD1A low voltage dc bus is shown. SWHA1、SWHA2、SWHD1、SWHA1`、SWHA2`、SWHD1Denoted "respective high-side alternating-current or direct-current circuit breakers, SWLA1、SWLA2、SWLD1、SWLA1`、SWLA2`、SWLD1Denoted "respective low-side ac or dc circuit breakers, SWBThe bus tie is a circuit breaker for connecting two buses in a transformer substation.
The power electronic transformer in fig. 2 includes two parts, one is a main circuit and the other is a control circuit. The main circuit can be in various types based on the internal topology and interface requirements, and fig. 3 is one of the main circuits and is a schematic structural diagram of the power electronic transformer for the flexible substation. It contains 5 transform modules inside. As can be seen from fig. 3, the five modules are: the high-frequency transformer comprises an AC/DC converter of a first stage, a DC/AC converter of a second stage, a high-frequency transformer of a third stage, an AC/DC converter of a fourth stage and a DC/AC converter of a fifth stage. Usually, the first stage takes high-voltage ac power from the grid as input to the power electronic transformer, and the fifth stage outputs low-voltage ac power for ac loads.
To the reliability analysis of the hybrid ac/dc distribution network containing the flexible substation of fig. 2, the problems to be considered include: the flexible transformer substation is different from a conventional transformer substation in configuration and structure, and particularly comprises a novel primary power device such as a power electronic transformer, and a direct-current power supply is mostly in a state of unstable output.
FIG. 4 shows a hybrid substation with flexible substationAnd (4) a load point power supply path diagram during the reliability calculation of the alternating current-direct current distribution network. And the DC load is supplied by only DG together with the AC power supply 1 and the AC power supply 2, wherein the DC charging and discharging load for storage is in a charging mode when the load is used. Path 1 in the figure, high voltage ac power supply AG1Incoming line is through exchanging circuit breaker SWHA1Is connected to the incoming line side BUSHA1Sequentially through the circuit breaker SWHA1Electric power electronic transformer T1High voltage AC measurement1And 4 conversion modules to DC LOAD LOADD11And supplying power, wherein the fault rate of the power electronic transformer can be calculated according to the following formula:
Figure GDA0002984416150000161
the specific process of using the hybrid alternating current/direct current power distribution network containing the flexible substation to perform reliability analysis is similar to that of the method embodiment, and is not described again here.
In summary, in the embodiments of the present invention, the reliability parameter of the distributed power supply DG is determined by obtaining the network topology and the element reliability parameter value of the power distribution network; constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network; establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to a load according to whether the distributed power supply DG can meet the load requirement independently; according to the minimum cut set theory, utilizing a multi-power supply fault tree or a single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network; and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network. The method solves the problem of reliability evaluation of the power distribution network under the condition that the power electronic transformer equipment which is not commercially operated is applied to the flexible transformer substation, and provides technical support for the research and planning design of the flexible transformer substation project; the method which takes the internal module of the power electronic transformer as the reliability calculation unit is provided, so that the reliability analysis of the power distribution network with the flexible transformer substation is simple and feasible, and the engineering requirements can be met.
Those of ordinary skill in the art will understand that: the figures are merely schematic representations of one embodiment, and the blocks or flow diagrams in the figures are not necessarily required to practice the present invention.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for apparatus or system embodiments, since they are substantially similar to method embodiments, they are described in relative terms, as long as they are described in partial descriptions of method embodiments. The above-described embodiments of the apparatus and system are merely illustrative, and the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (8)

1. A reliability assessment method for a hybrid alternating current-direct current power distribution network comprising a flexible substation is characterized by comprising the following steps:
acquiring network topology and element reliability parameter values of the power distribution network;
determining a reliability parameter of a distributed power supply DG;
constructing a reliability model of the power electronic transformer according to the network topology of the power distribution network; the method comprises the following steps:
a current converter and a high-frequency transformer in the power electronic transformer obtain reliability parameters by referring to historical operating data;
determining power supply paths of load points according to the network topology of the power distribution network, further determining the operation mode of a power electronic transformer and the modules of the power electronic transformer in each power supply path, and participating the modules in operation;
the modules are 5 conversion modules of the power electronic transformer PET, and the failure rate of each module is set as PpetjReliability P of the transformation module of said power electronic transformerpetjThe known parameters are obtained by statistics of historical operating data of the transformation module, and the repair time is RpetjAnd calculating the annual fault time, wherein j is 1 … … m, m is 5 m, and m is the number of modules input by the power electronic transformer, so that the fault rate of the power electronic transformer is as follows:
Figure FDA0002984416140000011
establishing a multi-power supply fault tree or a single-power supply fault tree corresponding to the load according to whether the distributed power supply DG can meet the load requirement independently; the method comprises the following steps:
judging whether the distributed power supply DG can independently meet the load requirement, if the reliability parameter of the distributed power supply DG can independently meet the load requirement, establishing a multi-power-supply fault tree corresponding to the load, and if the reliability parameter of the distributed power supply DG cannot independently meet the load requirement, establishing a single-power-supply fault tree corresponding to the load;
defining the system fault as a top event, and recording the system fault as a top event A when the power sent by the DG is greater than or equal to the power required by the load in the power distribution network1Otherwise, it is top event A2(ii) a Accordingly, network topology and load point power supply paths under the condition that load requirements can be met or cannot be met independently are analyzed respectively, element faults are generated from top events to bottom events through layer-by-layer analysis according to the fault tree theory, and a fault tree diagram F corresponding to loads is established for each load pointTAk，k＝1，2；
According to a minimum cut set theory, utilizing the multi-power supply fault tree or the single-power supply fault tree to respectively calculate the reliability index of each load in the power distribution network;
and calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network.
2. The method for evaluating the reliability of the hybrid alternating current-direct current power distribution network comprising the flexible substation according to claim 1, wherein the step of obtaining the network topology and element reliability parameter values of the power distribution network comprises the following steps:
the network topology of the power distribution network comprises: the system comprises a flexible transformer substation, a high-voltage alternating current network, a high-voltage direct current network, a low-voltage alternating current network and a low-voltage direct current network;
the high-voltage alternating current network is connected with a high-voltage alternating current power supply and is connected with the flexible transformer substation through a high-voltage alternating current inlet wire;
the high-voltage direct-current network is connected with a high-voltage direct-current power supply and is connected with the flexible transformer substation through a high-voltage direct-current incoming line;
the low-voltage alternating current network is connected with the flexible transformer substation through a low-voltage alternating current outlet wire and is connected with a low-voltage alternating current load;
the low-voltage direct-current network is connected with the flexible substation through a low-voltage direct-current outlet and is connected with a low-voltage direct-current load.
3. The method for evaluating the reliability of the hybrid alternating current/direct current power distribution network comprising the flexible substation according to claim 2, wherein the step of obtaining the network topology and the element reliability parameter values of the power distribution network further comprises the following steps:
the element is an element of a power distribution network containing a flexible substation, and comprises the following components: power electronic transformers, circuit breakers, disconnectors, busbars, distribution lines and power transformers, the elements within the flexible substation include but are not limited to: the power electronic transformer, the circuit breaker, the isolating switch and the bus;
the distribution line is an overhead line or a cable;
the circuit breaker includes: direct current circuit breakers and alternating current circuit breakers;
the power electronic transformer includes: the main circuit comprises 5 transformation modules based on internal topology and interfaces: the power electronic transformer comprises a first-stage AC/DC converter, a second-stage DC/AC converter, a third-stage high-frequency transformer, a fourth-stage AC/DC converter and a fifth-stage DC/AC converter, wherein the first-stage AC/DC converter takes high-voltage alternating current as input of the power electronic transformer, and the fifth-stage DC/AC converter outputs low-voltage alternating current for use by an alternating-current load;
the power electronic transformer includes but is not limited to: the device is provided with a direct current port and an alternating current port;
the bus adopts the following steps: single bus, single bus segment, bridge connection, double bus or double bus segment.
4. The method for evaluating the reliability of the hybrid alternating current-direct current power distribution network comprising the flexible substation according to claim 3, wherein the step of obtaining the network topology and the element reliability parameter values of the power distribution network further comprises the following steps:
the flexible transformer substation and the high-voltage alternating current network, the high-voltage direct current network, the low-voltage alternating current network and the low-voltage direct current network are in a topological mode as follows:
the inlet wire of the flexible transformer substation: the DC power supply in the high-voltage DC network is connected with the incoming line side BUS BUS through the DC breakerHDSaid BUSHDThe other side of the direct current circuit breaker is connected to the high-voltage direct current side of the power electronic transformer through the direct current circuit breaker;
the alternating current power supply in the high-voltage alternating current network is connected with an inlet wire side BUS BUS through the two alternating current circuit breakers respectivelyHA1、BUSHA2Said BUSHA1And said BUSHA2By means of a sectionalising breaker SWBConnected, the BUSHA1Connected to the high voltage AC side of the power electronic transformer via the AC circuit breaker, the BUSHA2Is connected to the high-voltage side of a power transformer through the alternating-current circuit breaker;
the outgoing line of the flexible transformer substation is as follows: the low-voltage direct-current network comprises a direct-current LOAD (LOAD)D11And a bidirectional charging and discharging device LOADD12The LOADD11And said LOADD12The low-voltage direct-current side of the power electronic transformer is connected with the direct-current circuit breaker and the low-voltage direct-current bus in sequence;
sensitive AC LOAD LOAD in the low-voltage AC networkA1The low-voltage alternating-current bus is connected to the low-voltage alternating-current side of the power electronic transformer through the alternating-current circuit breaker and the low-voltage alternating-current bus in sequence;
a normal AC LOAD LOAD in the low voltage AC networkA2And the low-voltage side of the power transformer is connected with the low-voltage side of the power transformer through the alternating-current circuit breaker and the low-voltage alternating-current bus in sequence.
5. The method for evaluating the reliability of the hybrid alternating current-direct current power distribution network comprising the flexible substation according to claim 4, wherein the step of obtaining the network topology and the element reliability parameter values of the power distribution network further comprises the following steps:
the element reliability parameter values include: failure rate and repair time;
the fault rates and the repair time of the power electronic transformer, the bus, the circuit breaker and the distribution line are obtained by searching according to historical statistical data, and the fault rates of the power electronic transformer, the bus, the circuit breaker and the distribution line are respectively as follows: pT、PBUS、PSW、PLINEThe repair time of the power electronic transformer, the bus, the breaker and the distribution line is respectively as follows: rT、RBUS、RSW、RLINE。
6. The method according to claim 1, wherein the determining reliability parameters of the distributed generation DG comprises:
setting the reliability parameter of the distributed power supply DG as PDG；
Predetermining installed capacity of distributed power supply DG, and giving fault rate of distributed power supply lambdaDGFault repair time of RDGDistributed generation DG according to the area of the siteThe historical operating data of (1) is T in annual operating hoursDGAcquiring the output power of the distributed power supply DG, comparing the output power with the load power, and setting the probability and the fault rate of the distributed power supply DG without power output as PDGiI is 1, 2; then P isDGComprises the following steps:
Figure FDA0002984416140000041
wherein 8760 is 24 hours/day × 365 days/year, which refers to the number of hours of a year, and the unit is hour h;
Figure FDA0002984416140000042
RDGthe fault repairing time of the DG is a known parameter for calculating reliability, and is obtained through historical operation data statistics of the DG;
Figure FDA0002984416140000051
wherein, PDGiThe results of calculation according to the formulas (1) and (2) are shown.
7. The method for evaluating the reliability of the hybrid alternating current/direct current power distribution network comprising the flexible substation according to claim 1, wherein the step of respectively calculating the reliability index of each load in the power distribution network by using the multi-power-supply fault tree or the single-power-supply fault tree according to a minimum cut-set theory comprises the following steps:
according to the minimal cut set theory, obtaining A from the fault tree diagram1、A2Minimal cut sets in two states: a. the11…A1m，A21…A2nWherein A isk＝{Xk1,Xk2,…,XklIs bottom event XklA set of (a);
calculating the load point A according to the formulas (5) and (6)1、A2Annual failure rate in both cases
Figure FDA0002984416140000052
Annual power off time
Figure FDA0002984416140000053
Then weighting according to formulas (7) and (8) to obtain the annual fault rate P of the load pointLOADD11Annual power failure time TLOADD11；
Figure FDA0002984416140000054
Figure FDA0002984416140000055
Figure FDA0002984416140000056
Figure FDA0002984416140000057
Figure FDA0002984416140000058
Wherein alpha is2＝1-α1。
8. The method for evaluating the reliability of the hybrid alternating current-direct current power distribution network comprising the flexible substation according to claim 1, wherein the step of calculating the reliability index of the power distribution network according to the reliability index of each load in the power distribution network comprises the following steps:
sequentially calculating the annual fault rate P of S load points in the power distribution networkloadtAnnual power failure time TloadtThen to distribute powerThe overall annual failure rate of the net is:
Figure FDA0002984416140000061
the whole annual power failure time of the power distribution network is as follows:
Figure FDA0002984416140000062
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106971264A (en) * 2017-03-21 2017-07-21 华北电力大学 A kind of alternating current-direct current mixing micro-capacitance sensor analysis method for reliability
CN107633333A (en) * 2017-10-16 2018-01-26 国家电网公司 The source lotus storage method for optimizing scheduling and system of flexible transformer station's regional power grid

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106971264A (en) * 2017-03-21 2017-07-21 华北电力大学 A kind of alternating current-direct current mixing micro-capacitance sensor analysis method for reliability
CN107633333A (en) * 2017-10-16 2018-01-26 国家电网公司 The source lotus storage method for optimizing scheduling and system of flexible transformer station's regional power grid

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
《含分布式电源配电网可靠性评估方法研究》;魏如峰;《CNKI优秀硕士论文库》;20160505;第27-28页 *
《电力电子变压器技术研究综述》;李子欣等;《中国电机工程学报》;20180305;第38卷(第5期);第1274-1289页 *

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