CN113270868A - Dynamic load flow calculation method for power supply system of alternating current electrified railway train - Google Patents

Dynamic load flow calculation method for power supply system of alternating current electrified railway train Download PDF

Info

Publication number
CN113270868A
CN113270868A CN202110562730.0A CN202110562730A CN113270868A CN 113270868 A CN113270868 A CN 113270868A CN 202110562730 A CN202110562730 A CN 202110562730A CN 113270868 A CN113270868 A CN 113270868A
Authority
CN
China
Prior art keywords
node
power supply
nodes
chain circuit
section
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202110562730.0A
Other languages
Chinese (zh)
Other versions
CN113270868B (en
Inventor
王辉
李群湛
刘炜
马庆安
刘童童
金琳
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southwest Jiaotong University
Original Assignee
Southwest Jiaotong University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southwest Jiaotong University filed Critical Southwest Jiaotong University
Priority to CN202110562730.0A priority Critical patent/CN113270868B/en
Publication of CN113270868A publication Critical patent/CN113270868A/en
Application granted granted Critical
Publication of CN113270868B publication Critical patent/CN113270868B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • 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
    • H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
    • 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]

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention belongs to the technical field of rail transit power supply, and particularly relates to a dynamic load flow calculation method for an alternating current electrified railway train power supply system. The method comprises the steps of dividing external power supplies, power transmission lines, traction substations, feeders and traction networks in a power supply system into sections based on train positions and train power, so as to construct chain circuits of the power transmission lines, the feeders and the traction networks, and then constructing power source iterative models based on node voltage equations of the chain circuits, so as to obtain voltages of each section node. The method can better integrate dynamic power flow solution of the train power supply system, simultaneously considers the condition of multiple loads at the common connecting point, can realize direct solution of the PV node, and is suitable for power flow calculation of the rail transit power supply alternating current power supply system in various occasions.

Description

Dynamic load flow calculation method for power supply system of alternating current electrified railway train
Technical Field
The invention belongs to the technical field of rail transit power supply, and particularly relates to a dynamic load flow calculation method for an alternating current electrified railway train power supply system.
Background
The method has the advantages that dynamic load flow calculation is carried out on the power supply system of the alternating current electrified railway train, the train load process is obtained, and the method has important engineering practical significance for optimization and design of the train power supply system, safe line operation, reasonable and efficient resource utilization and the like [1 ]. The load of the train is a single-phase high-power dynamic load, and has the characteristics of random volatility, quick mobility and the like; according to different line conditions, different traction network power supply modes exist, such as a direct supply mode with a return wire and an autotransformer power supply mode, so that the topological structure of the traction network is more special and complex. Therefore, the conventional load flow calculation method cannot be completely used to obtain the load process of the electrified railway.
The current research does not consider the situation of multiple loads at a common connection point, and the external power supply is generally equivalent, and the emphasis is placed on modeling of a traction power supply system. In order to better integrate dynamic power flow solving of a train power supply system, particularly in a weak power grid area, combined modeling and simulation of an external power supply and a traction power supply system need to be considered. In addition, with the development of research and application of new energy resources and the like in a rail transit power supply system, control modes are different, and node types are different when load flow calculation is performed, for example, a PQ node, a PV node and the like, a PV node cannot be directly solved by adopting a current source iterative model, and a general solution model of a power source iterative model needs to be constructed.
Disclosure of Invention
Aiming at the problems, the invention aims to provide a dynamic load flow calculation method for an alternating current electrified railway train power supply system, which can realize direct solution of PV nodes by considering the condition of multiple loads at a common connecting point and is suitable for load flow calculation of the alternating current electrified railway train power supply system in various occasions.
The technical scheme of the invention is as follows:
the dynamic load flow calculation method for the power supply system of the alternating current electrified railway train comprises the following steps:
s1, inputting original data including line parameters, train parameters and driving strategies, and obtaining a train operation diagram, train positions at corresponding moments and train power through traction calculation;
s2, the train power supply system comprises an external power supply, a power transmission line, a traction substation, a feeder line and a traction network which are connected in sequence; the method comprises the following steps that an upper-level transformer substation of a traction substation is used as an equivalent demarcation point of an external power supply, the external power supply is equivalent to an ideal voltage source in series equivalent impedance, and the equivalent external power supply is located in the upper-level transformer substation of the traction substation and is connected with the traction substation through a power transmission line; dividing the section of an equivalent train power supply system, and constructing chain circuits of a transmission line, a feeder line and a traction network, wherein the interval of dividing the section of the traction network is determined according to parallel elements in the traction network and the position of a train, the constructed chain circuit of the transmission line is defined as a first chain circuit, the constructed chain circuit of the feeder line is defined as a second chain circuit, and the constructed chain circuit of the traction network is defined as a third chain circuit, namely, interfaces at two ends of the first chain circuit are respectively connected with an external power supply and a traction substation, interfaces at two ends of the second chain circuit are respectively connected with the traction substation and the traction network, and interfaces at two ends of the third chain circuit are respectively connected with the feeder line and the train; the section numbers corresponding to the first chain circuit are marked as 1-N1The section number corresponding to the second chain circuit is marked as N1+1～N2And the section number corresponding to the third chain circuit is marked as N2+1～N3(ii) a The equivalent external power supply is positioned at the section 1; the primary winding and the secondary winding of the traction transformer are respectively positioned on the tangent plane N1And section N1+ 1; section N of the third chain circuit2+p2And N2+p2+1 is the section, p, corresponding to the two power supply arm ports2And p2+1 is the tangent plane N between the port of the two power supply arms and the third chain circuit2The section distance of (a); section N in chain circuit 22From section N of the chain circuit 32+p2And N2+p2+1 formed together, i.e. section N2Is a public section; according to the connection relation among the sections, a train supply formed by a first chain circuit, a second chain circuit and a third chain circuit is constructedThe node voltage equation of the electrical system is:
I1＝Y1U1 (1)
wherein, I1Injecting a current matrix into nodes of all nodes in a train power supply system, wherein the current of the injected nodes of the section of the train in the third chained circuit is obtained according to the train power and the port voltage of the train, and U is1Node voltage matrix, Y, for all nodes in a train power supply system1A node admittance matrix formed by admittance between nodes in the train power supply system;
s3, a feeder connected with a contact line in a direct supply mode or an autotransformer power supply mode is called a positive power supply line, and a feeder connected with a steel rail in the direct supply mode or a feeder connected with a negative feeder in the autotransformer power supply mode is called a negative power supply line; reordering the nodes in formula (1) to obtain another expression of formula (1):
Figure BDA0003079585950000021
wherein,
Figure BDA0003079585950000022
I21from section 1 to N in the first chain circuit1The node current of (1); i is22From the middle section N of the second chain circuit1+1～N2-a positive supply line node current of 1 and a contact line node current in the third chain circuit; i is23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node current and rail node current in the third chain circuit; u shape21From section 1 to N in the first chain circuit1The node voltage of (1); u shape22From the middle section N of the second chain circuit1+1～N2-a positive supply line node voltage of 1 and a contact line node voltage in the third chain circuit; u shape23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node voltage and rail node in third chain circuitVoltage formation; u shape3A matrix formed by node voltages of the remaining nodes; y is11Is U2Admittance matrixes between the middle corresponding nodes and the nodes; y is12Is U2Middle corresponding node and U3Admittance matrices between the middle corresponding nodes; y is21Is U3Middle corresponding node and U2Admittance matrices between the middle corresponding nodes; y is22Is U3Admittance matrixes between the middle corresponding nodes and the nodes;
s4, combining the equations of part 1 and part 2 of the block matrix of equation (2):
Figure BDA0003079585950000031
formula (3) is multiplied on both sides
Figure BDA0003079585950000032
To obtain
Figure BDA0003079585950000033
Wherein,
Figure BDA0003079585950000034
Z11is U21The impedance matrix between the middle corresponding node and the node; z12Is U21Middle corresponding node and U22An impedance matrix between the corresponding nodes; z13Is U21Middle corresponding node and U23An impedance matrix between the corresponding nodes; z22Is U22The impedance matrix between the middle corresponding node and the node; z21Is U22Middle corresponding node and U21An impedance matrix between the corresponding nodes; z23Is U22Middle corresponding node and U23An impedance matrix between the corresponding nodes; z33Is U23The impedance matrix between the middle corresponding node and the node; z31Is U23Middle corresponding node and U21An impedance matrix between the corresponding nodes; z32Is U23Middle corresponding node and U22An impedance matrix between the corresponding nodes;
let IL＝I22＝-I23，UL＝U22-U23Is shown byLAnd ULIn the formula (4), the node voltage equation solved by adopting the power source iterative model basic model is obtained as
Figure BDA0003079585950000035
Wherein, ILA node current matrix formed by node currents corresponding to a positive power supply line node and a contact line node; u shapeLA node voltage matrix formed by the voltage between the positive power supply line node and the negative power supply line node and the voltage between the contact line and the steel rail; z'11＝Z11Is U21The impedance matrix between the middle corresponding node and the node; z'12＝Z12+Z13Is U21Middle corresponding node and ULAn impedance matrix between the corresponding nodes; z'21＝Z12-Z13Is ULMiddle corresponding node and U21An impedance matrix between the corresponding nodes; z'22＝Z23+Z32-Z22-Z33Is ULThe impedance matrix between the middle corresponding node and the node;
s5, where the total number of nodes in the setting formula (5) is f, and the injection power of any node c is assumed to be Pc+jQc，c＝1,2,···，f，PcIs active power, QcIf j is a complex unit, the injection power equation of the node c is obtained from equation (5):
Figure BDA0003079585950000041
wherein d is the number of the corresponding node, d is 1,2, f,
Figure BDA0003079585950000042
and
Figure BDA0003079585950000043
node voltage phasor forms of nodes c and d, YcdCalculating the conjugation for the admittance between the nodes c and d;
the active power P at the node c under the polar coordinate is obtained by the formula (5)cAnd reactive power QcIs given by the equation
Figure BDA0003079585950000044
Wherein, deltacAnd deltadThe voltage phase angles of nodes c and d, respectively; deltacd＝δc-δd；UcAnd UdVoltage modulus values of nodes c and d, respectively; gcdAnd bcdIs YcdThe real and imaginary parts of (c); Σ denotes summation;
the iteration equation of the basic model of the power source iteration model after k times of calculation is obtained by the formula (6)
Figure BDA0003079585950000045
Wherein (C)(k)Representing the k-th calculation result of the variable, wherein when k is 0, the value of the variable is an initial value;
s6, order
Figure BDA0003079585950000046
Setting convergence accuracy to epsilon, setting k-th and k + 1-th iteration voltages to
Figure BDA0003079585950000047
And
Figure BDA0003079585950000048
to be provided with
Figure BDA0003079585950000049
As a convergence criterion, based onAnd (4) forming a correction equation of all the nodes by the formula (8), solving by using a Newton Raphson method, updating the voltage value of each node, and solving the voltage of each tangent plane node.
A method for carrying out load flow calculation by improving a power source iterative model is provided as follows:
dividing the tangent planes in the first chain circuit, the second chain circuit and the third chain circuit into a common connection point tangent plane, a load node tangent plane and a connection node tangent plane, wherein the tangent plane 1 is the common connection point tangent plane; the load node section refers to a section in which node current injection exists; the connection node section is a section without current injection; when reordering the nodes of formula (1) in step S3 of claim 1, I2And U2In the node, only the load node section is reserved, and the load node section is classified into U in the node3In (1), the rest of the solving processes are unchanged.
A method for carrying out load flow calculation by improving a power source iterative model is provided as follows:
dividing nodes in the first chained circuit, the second chained circuit and the third chained circuit into a balance node, a load node and a connection node, wherein the node at the section 1 in the train power supply system is regarded as the balance node, the voltage amplitude and the phase of the node are known, and the node with current injection in the train power supply system is called the load node; the remaining nodes in the train power supply system are contact nodes, and when reordering the nodes in formula (1) in step S3 of claim 1, I2And U2Only the load node is reserved, and the load node is classified into U in the node3In (1), the rest of the solving processes are unchanged.
The invention has the beneficial effects that: 1) the condition of multiple loads at the common connecting point is considered, dynamic load flow solving can be better integrally carried out on the train power supply system, and the calculation result is more complex to the actual condition; 2) the PV node can be directly solved, and the application range is wider; 3) the invention has simple result, reliable technology, excellent performance and convenient implementation.
Drawings
Fig. 1 is a schematic structural diagram of a train power supply system according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a chain circuit of the train power supply system in the embodiment of the invention.
Fig. 3 is a schematic structural diagram of the chain circuit 3 in the embodiment of the present invention.
Detailed Description
The technical scheme of the invention is described in detail below with reference to the accompanying drawings and embodiments:
example 1
As shown in fig. 1, which is a schematic structural diagram of the train power supply system of this example, a public power grid substation transmits electric energy to a traction substation through a three-phase power transmission line, the traction substation is provided with a traction transformer, the electric energy with a high voltage level of 110 kV, 220 kV or 330kV is converted into electric energy with a voltage level of 27.5kV, 55 kV or 2 × 27.5kV, and the electric energy is transmitted to the traction grid through a feeder line to supply power to trains. In fig. 1, the traction transformer is a three-phase two-phase connection transformer, and includes an YNd11 connection wire, a Vv connection wire, a Scott connection wire, etc., and the secondary side of the traction transformer forms two ports, which are respectively connected to an α power supply arm port and a β power supply arm port, or a single-phase connection transformer, which has only one port; in fig. 1, the traction network may adopt a direct supply mode, a direct supply mode with a return line, an AT power supply mode, and the like.
The transmission line, the feeder line and the traction network are parallel multi-conductor transmission lines, and are respectively divided into sections to form chain circuits 1,2 and 3, as shown in figure 2, the numbers corresponding to the sections are respectively 1-N1、N1+1～N2And N2+1～N3. The chain circuit 1 is connected with a public power grid transformer substation and a traction transformer through interfaces 1 and 2 respectively; the chain circuit 2 is connected with a traction transformer and a traction network through interfaces 2 and 3 respectively; the chain circuit 3 is connected to the feeder and the train via interfaces 4 and 5, respectively.
The chain circuit 3 is more complex and consists of parallel elements and series elements, as shown in fig. 3. Z in FIG. 3iAn impedance matrix for the transverse element between sections i and i + 1; i isiA node current matrix at a tangent plane i; y isiA node admittance matrix at a tangent plane i; the series elements comprise a traction network circuit, a series compensation device and the like; parallel elements having transverse connecting wires, AT-supplied autotransformer and in traction substationA joint compensation device and the like; the port of the alpha power supply arm and the port of the beta power supply arm are respectively connected to two ports of the secondary side of the traction transformer; section N of the third chain circuit2+p2And N2+p2+1 is the section, p, corresponding to the two power supply arm ports2And p2+1 is the tangent plane N between the port of the two power supply arms and the third chain circuit2The interface 4 is a common connection section of the chain circuits 2 and 3, so that the section N in the chain circuit 22Can be regarded as a tangent plane N in the chain circuit 32+p2And N2+p2+1 together.
The embodiment specifically comprises the following steps:
s1, inputting original data including line parameters, train parameters and driving strategies, and obtaining a train operation diagram, train positions at corresponding moments and train power through traction calculation;
s2, the train power supply system comprises an external power supply, a power transmission line, a traction substation, a feeder line and a traction network which are connected in sequence; the method comprises the following steps that an upper-level transformer substation of a traction substation is used as an equivalent demarcation point of an external power supply, the external power supply is equivalent to an ideal voltage source in series equivalent impedance, and the equivalent external power supply is located in the upper-level transformer substation of the traction substation and is connected with the traction substation through a power transmission line; dividing the section of an equivalent train power supply system, and constructing chain circuits of a transmission line, a feeder line and a traction network, wherein the interval of dividing the section of the traction network is determined according to parallel elements in the traction network and the position of a train, the constructed chain circuit of the transmission line is defined as a first chain circuit, the constructed chain circuit of the feeder line is defined as a second chain circuit, and the constructed chain circuit of the traction network is defined as a third chain circuit, namely, interfaces at two ends of the first chain circuit are respectively connected with an external power supply and a traction substation, interfaces at two ends of the second chain circuit are respectively connected with the traction substation and the traction network, and interfaces at two ends of the third chain circuit are respectively connected with the feeder line and the train; the section numbers corresponding to the first chain circuit are marked as 1-N1The section number corresponding to the second chain circuit is marked as N1+1～N2And the section number corresponding to the third chain circuit is marked as N2+1～N3(ii) a The equivalent external power supply is positioned at the section 1; the primary winding and the secondary winding of the traction transformer are respectively positioned on the tangent plane N1And section N1+ 1; section N of the third chain circuit2+p2And N2+p2+1 is the section, p, corresponding to the two power supply arm ports2And p2+1 is the tangent plane N between the port of the two power supply arms and the third chain circuit2The section distance of (a); section N in chain circuit 22From section N of the chain circuit 32+p2And N2+p2+1 formed together, i.e. section N2Is a public section; according to the connection relation among the sections, a node voltage equation of a train power supply system formed by the first chain circuit, the second chain circuit and the third chain circuit is constructed as follows:
I1＝Y1U1 (1)
wherein, I1Injecting a current matrix into nodes of all nodes in a train power supply system, wherein the current of the injected nodes of the section of the train in the third chained circuit is obtained according to the train power and the port voltage of the train, and U is1Node voltage matrix, Y, for all nodes in a train power supply system1A node admittance matrix formed by admittance between nodes in the train power supply system;
s3, a feeder connected with a contact line in a direct supply mode or an autotransformer power supply mode is called a positive power supply line, and a feeder connected with a steel rail in the direct supply mode or a feeder connected with a negative feeder in the autotransformer power supply mode is called a negative power supply line; reordering the nodes in formula (1) to obtain another expression of formula (1):
Figure BDA0003079585950000071
wherein,
Figure BDA0003079585950000072
I21from section 1 to N in the first chain circuit1The node current of (1); i is22From the middle section N of the second chain circuit1+1～N2-a positive supply line node current of 1 and a contact line node current in the third chain circuit; i is23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node current and rail node current in the third chain circuit; u shape21From section 1 to N in the first chain circuit1The node voltage of (1); u shape22From the middle section N of the second chain circuit1+1～N2-a positive supply line node voltage of 1 and a contact line node voltage in the third chain circuit; u shape23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node voltage and rail node voltage in the third chain circuit; u shape3A matrix formed by node voltages of the remaining nodes; y is11Is U2Admittance matrixes between the middle corresponding nodes and the nodes; y is12Is U2Middle corresponding node and U3Admittance matrices between the middle corresponding nodes; y is21Is U3Middle corresponding node and U2Admittance matrices between the middle corresponding nodes; y is22Is U3Admittance matrixes between the middle corresponding nodes and the nodes;
s4, combining the equations of part 1 and part 2 of the block matrix of equation (2):
Figure BDA0003079585950000073
formula (3) is multiplied on both sides
Figure BDA0003079585950000074
To obtain
Figure BDA0003079585950000075
Wherein,
Figure BDA0003079585950000076
Z11is U21The impedance matrix between the middle corresponding node and the node; z12Is U21Middle corresponding node and U22An impedance matrix between the corresponding nodes; z13Is U21Middle corresponding node and U23An impedance matrix between the corresponding nodes; z22Is U22The impedance matrix between the middle corresponding node and the node; z21Is U22Middle corresponding node and U21An impedance matrix between the corresponding nodes; z23Is U22Middle corresponding node and U23An impedance matrix between the corresponding nodes; z33Is U23The impedance matrix between the middle corresponding node and the node; z31Is U23Middle corresponding node and U21An impedance matrix between the corresponding nodes; z32Is U23Middle corresponding node and U22An impedance matrix between the corresponding nodes;
let IL＝I22＝-I23，UL＝U22-U23Is shown byLAnd ULIn the formula (4), the node voltage equation solved by adopting the power source iterative model basic model is obtained as
Figure BDA0003079585950000081
Wherein, ILA node current matrix formed by node currents corresponding to a positive power supply line node and a contact line node; u shapeLA node voltage matrix formed by the voltage between the positive power supply line node and the negative power supply line node and the voltage between the contact line and the steel rail; z'11＝Z11Is U21The impedance matrix between the middle corresponding node and the node; z'12＝Z12+Z13Is U21Middle corresponding node and ULAn impedance matrix between the corresponding nodes; z'21＝Z12-Z13Is ULMiddle corresponding node and U21An impedance matrix between the corresponding nodes; z'22＝Z23+Z32-Z22-Z33Is ULMiddle corresponding jointAn impedance matrix between the points and the nodes;
s5, where the total number of nodes in the setting formula (5) is f, and the injection power of any node c is assumed to be Pc+jQc，c＝1,2,···，f，PcIs active power, QcIf j is a complex unit, the injection power equation of the node c is obtained from equation (5):
Figure BDA0003079585950000082
wherein d is the number of the corresponding node, d is 1,2, f,
Figure BDA0003079585950000083
and
Figure BDA0003079585950000084
node voltage phasor forms of nodes c and d, YcdCalculating the conjugation for the admittance between the nodes c and d;
the active power P at the node c under the polar coordinate is obtained by the formula (5)cAnd reactive power QcIs given by the equation
Figure BDA0003079585950000085
Wherein, deltacAnd deltadThe voltage phase angles of nodes c and d, respectively; deltacd＝δc-δd；UcAnd UdVoltage modulus values of nodes c and d, respectively; gcdAnd bcdIs YcdThe real and imaginary parts of (c); Σ denotes summation;
the iteration equation of the basic model of the power source iteration model after k times of calculation is obtained by the formula (6)
Figure BDA0003079585950000091
Wherein (C)(k)K number of times of representing variableCalculating a result, wherein when k is 0, the value of the variable is an initial value;
s6, order
Figure BDA0003079585950000092
Setting convergence accuracy to epsilon, setting k-th and k + 1-th iteration voltages to
Figure BDA0003079585950000093
And
Figure BDA0003079585950000094
to be provided with
Figure BDA0003079585950000095
And (3) forming a correction equation of all nodes according to the formula (8) as a convergence criterion, solving by using a Newton Raphson method, updating the voltage value of each node, and obtaining the voltage of each tangent plane node.

Claims (3)

1. The dynamic power flow calculation method for the power supply system of the alternating current electrified railway train is characterized by comprising the following steps of:
s1, inputting original data including line parameters, train parameters and driving strategies, and obtaining a train operation diagram, train positions at corresponding moments and train power through traction calculation;
s2, the train power supply system comprises an external power supply, a power transmission line, a traction substation, a feeder line and a traction network which are connected in sequence; the method comprises the following steps that an upper-level transformer substation of a traction substation is used as an equivalent demarcation point of an external power supply, the external power supply is equivalent to an ideal voltage source in series equivalent impedance, and the equivalent external power supply is located in the upper-level transformer substation of the traction substation and is connected with the traction substation through a power transmission line; dividing the equivalent train power supply system into sections, and constructing chain circuits of a transmission line, a feeder line and a traction network, wherein the interval of dividing the section of the traction network is determined according to parallel elements in the traction network and the position of a train, the constructed chain circuit of the transmission line is defined as a first chain circuit, the constructed chain circuit of the feeder line is defined as a second chain circuit, and the constructed chain circuit of the traction network is defined as a second chain circuitThe circuit is defined as a third chain circuit, namely, interfaces at two ends of the first chain circuit are respectively connected with an external power supply and a traction substation, interfaces at two ends of the second chain circuit are respectively connected with the traction substation and a traction network, and interfaces at two ends of the third chain circuit are respectively connected with a feeder line and a train; the section numbers corresponding to the first chain circuit are marked as 1-N1The section number corresponding to the second chain circuit is marked as N1+1～N2And the section number corresponding to the third chain circuit is marked as N2+1～N3(ii) a The equivalent external power supply is positioned at the section 1; the primary winding and the secondary winding of the traction transformer are respectively positioned on the tangent plane N1And section N1+ 1; section N of the third chain circuit2+p2And N2+p2+1 is the section, p, corresponding to the two power supply arm ports2And p2+1 is the tangent plane N between the port of the two power supply arms and the third chain circuit2The section distance of (a); section N in chain circuit 22From section N of the chain circuit 32+p2And N2+p2+1 formed together, i.e. section N2Is a public section; according to the connection relation among the sections, a node voltage equation of a train power supply system formed by the first chain circuit, the second chain circuit and the third chain circuit is constructed as follows:
I1＝Y1U1 (1)
wherein, I1Injecting a current matrix into nodes of all nodes in a train power supply system, wherein the current of the injected nodes of the section of the train in the third chained circuit is obtained according to the train power and the port voltage of the train, and U is1Node voltage matrix, Y, for all nodes in a train power supply system1A node admittance matrix formed by admittance between nodes in the train power supply system;
s3, a feeder connected with a contact line in a direct supply mode or an autotransformer power supply mode is called a positive power supply line, and a feeder connected with a steel rail in the direct supply mode or a feeder connected with a negative feeder in the autotransformer power supply mode is called a negative power supply line; reordering the nodes in formula (1) to obtain another expression of formula (1):
Figure FDA0003079585940000011
wherein,
Figure FDA0003079585940000021
I21from section 1 to N in the first chain circuit1The node current of (1); i is22From the middle section N of the second chain circuit1+1～N2-a positive supply line node current of 1 and a contact line node current in the third chain circuit; i is23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node current and rail node current in the third chain circuit; u shape21From section 1 to N in the first chain circuit1The node voltage of (1); u shape22From the middle section N of the second chain circuit1+1～N2-a positive supply line node voltage of 1 and a contact line node voltage in the third chain circuit; u shape23From the middle section N of the second chain circuit1+1～N2-1 negative supply line node voltage and rail node voltage in the third chain circuit; u shape3A matrix formed by node voltages of the remaining nodes; y is11Is U2Admittance matrixes between the middle corresponding nodes and the nodes; y is12Is U2Middle corresponding node and U3Admittance matrices between the middle corresponding nodes; y is21Is U3Middle corresponding node and U2Admittance matrices between the middle corresponding nodes; y is22Is U3Admittance matrixes between the middle corresponding nodes and the nodes;
s4, combining the equations of part 1 and part 2 of the block matrix of equation (2):
Figure FDA0003079585940000022
formula (3) is multiplied on both sides
Figure FDA0003079585940000023
To obtain
Figure FDA0003079585940000024
Wherein,
Figure FDA0003079585940000025
Z11is U21The impedance matrix between the middle corresponding node and the node; z12Is U21Middle corresponding node and U22An impedance matrix between the corresponding nodes; z13Is U21Middle corresponding node and U23An impedance matrix between the corresponding nodes; z22Is U22The impedance matrix between the middle corresponding node and the node; z21Is U22Middle corresponding node and U21An impedance matrix between the corresponding nodes; z23Is U22Middle corresponding node and U23An impedance matrix between the corresponding nodes; z33Is U23The impedance matrix between the middle corresponding node and the node; z31Is U23Middle corresponding node and U21An impedance matrix between the corresponding nodes; z32Is U23Middle corresponding node and U22An impedance matrix between the corresponding nodes;
let IL＝I22＝-I23，UL＝U22-U23Is shown byLAnd ULIn the formula (4), the node voltage equation solved by adopting the power source iterative model basic model is obtained as
Figure FDA0003079585940000026
Wherein, ILA node current matrix formed by node currents corresponding to a positive power supply line node and a contact line node; u shapeLFor the voltage between positive and negative supply line nodes and contact lineAnd the voltage between the steel rails to form a node voltage matrix; z'11＝Z11Is U21The impedance matrix between the middle corresponding node and the node; z'12＝Z12+Z13Is U21Middle corresponding node and ULAn impedance matrix between the corresponding nodes; z'21＝Z12-Z13Is ULMiddle corresponding node and U21An impedance matrix between the corresponding nodes; z'22＝Z23+Z32-Z22-Z33Is ULThe impedance matrix between the middle corresponding node and the node;
s5, where the total number of nodes in the setting formula (5) is f, and the injection power of any node c is assumed to be Pc+jQc，c＝1,2,···，f，PcIs active power, QcIf j is a complex unit, the injection power equation of the node c is obtained from equation (5):
Figure FDA0003079585940000031
wherein d is the number of the corresponding node, d is 1,2, f,
Figure FDA0003079585940000032
and
Figure FDA0003079585940000033
node voltage phasor forms of nodes c and d, YcdCalculating the conjugation for the admittance between the nodes c and d;
the active power P at the node c under the polar coordinate is obtained by the formula (5)cAnd reactive power QcIs given by the equation
Figure FDA0003079585940000034
Wherein, deltacAnd deltadThe voltage phase angles of nodes c and d, respectively; deltacd＝δc-δd；UcAnd UdVoltage modulus values of nodes c and d, respectively; gcdAnd bcdIs YcdThe real and imaginary parts of (c); Σ denotes summation;
the iteration equation of the basic model of the power source iteration model after k times of calculation is obtained by the formula (6)
Figure FDA0003079585940000035
Wherein (C)(k)Representing the k-th calculation result of the variable, wherein when k is 0, the value of the variable is an initial value;
s6, order
Figure FDA0003079585940000036
Setting convergence accuracy to epsilon, setting k-th and k + 1-th iteration voltages to
Figure FDA0003079585940000037
And
Figure FDA0003079585940000038
to be provided with
Figure FDA0003079585940000039
And (3) forming a correction equation of all nodes according to the formula (8) as a convergence criterion, solving by using a Newton Raphson method, updating the voltage value of each node, and obtaining the voltage of each tangent plane node.
2. The method for calculating the dynamic power flow of the alternating current electrified railway train power supply system according to claim 1, wherein the sections in the first chain circuit, the second chain circuit and the third chain circuit are divided into a common connection point section, a load node section and a connection node section, wherein the section 1 is the common connection point section; the load node section refers to a section in which node current injection exists; the connection node section is a section without current injection; in right toWhen reordering of the nodes in formula (1) in step S3 of 1 is required, I2And U2In the node, only the load node section is reserved, and the load node section is classified into U in the node3In (1), the rest of the solving processes are unchanged.
3. The method for calculating the dynamic power flow of the alternating current electrified railway train power supply system according to claim 1, wherein nodes in the first chain circuit, the second chain circuit and the third chain circuit are divided into a balance node, a load node and a contact node, wherein a node at a tangent plane 1 in the train power supply system is regarded as the balance node, the voltage amplitude and the phase of the node are known, and a node with current injection in the train power supply system is called the load node; the remaining nodes in the train power supply system are contact nodes, and when reordering the nodes in formula (1) in step S3 of claim 1, I2And U2Only the load node is reserved, and the load node is classified into U in the node3In (1), the rest of the solving processes are unchanged.
CN202110562730.0A 2021-05-24 2021-05-24 Dynamic load flow calculation method for power supply system of alternating current electrified railway train Active CN113270868B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110562730.0A CN113270868B (en) 2021-05-24 2021-05-24 Dynamic load flow calculation method for power supply system of alternating current electrified railway train

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110562730.0A CN113270868B (en) 2021-05-24 2021-05-24 Dynamic load flow calculation method for power supply system of alternating current electrified railway train

Publications (2)

Publication Number Publication Date
CN113270868A true CN113270868A (en) 2021-08-17
CN113270868B CN113270868B (en) 2022-06-24

Family

ID=77232430

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110562730.0A Active CN113270868B (en) 2021-05-24 2021-05-24 Dynamic load flow calculation method for power supply system of alternating current electrified railway train

Country Status (1)

Country Link
CN (1) CN113270868B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116388186A (en) * 2023-06-06 2023-07-04 清华大学 Tidal current calculation method, device, equipment and medium of alternating current traction power supply system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104462848A (en) * 2014-12-24 2015-03-25 南车株洲电力机车研究所有限公司 Short-circuit fault mathematical modeling and short-circuit current determining method for rail direct-current power supply system
CN105790274A (en) * 2016-03-09 2016-07-20 西南交通大学 Power flow control device and control method for run-through power supply system converter type traction substation
CN106253289A (en) * 2016-08-12 2016-12-21 成都运达科技股份有限公司 A kind of electric power supply system for subway power flow calculation method of car net coupling
CN109995037A (en) * 2017-12-29 2019-07-09 湖南工业大学 Tractive power supply system tidal current analysis method, system and the storage medium of meter and AC-DC coupling
CN110053521A (en) * 2019-03-08 2019-07-26 北京交通大学 Urban track traffic tractive power supply system and vehicle-net work-in parameters optimization method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104462848A (en) * 2014-12-24 2015-03-25 南车株洲电力机车研究所有限公司 Short-circuit fault mathematical modeling and short-circuit current determining method for rail direct-current power supply system
CN105790274A (en) * 2016-03-09 2016-07-20 西南交通大学 Power flow control device and control method for run-through power supply system converter type traction substation
CN106253289A (en) * 2016-08-12 2016-12-21 成都运达科技股份有限公司 A kind of electric power supply system for subway power flow calculation method of car net coupling
CN109995037A (en) * 2017-12-29 2019-07-09 湖南工业大学 Tractive power supply system tidal current analysis method, system and the storage medium of meter and AC-DC coupling
CN110053521A (en) * 2019-03-08 2019-07-26 北京交通大学 Urban track traffic tractive power supply system and vehicle-net work-in parameters optimization method

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
QUNZHAN LI等: "Study of the simulation of DC traction power supply system based on AC/DC unified Newton-Raphson method", 《2009 INTERNATIONAL CONFERENCE ON SUSTAINABLE POWER GENERATION AND SUPPLY》 *
高元海等: "计及接地阻抗及含多种分布式电源的中低压配电网三相潮流计算(一)：模型", 《中国电机工程学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116388186A (en) * 2023-06-06 2023-07-04 清华大学 Tidal current calculation method, device, equipment and medium of alternating current traction power supply system
CN116388186B (en) * 2023-06-06 2023-08-25 清华大学 Tidal current calculation method, device, equipment and medium of alternating current traction power supply system

Also Published As

Publication number Publication date
CN113270868B (en) 2022-06-24

Similar Documents

Publication Publication Date Title
CN106549384B (en) A kind of general tidal current computing method of the electric system containing UPFC
CN108134401B (en) Multi-target power flow optimization and control method for alternating current-direct current hybrid system
CN104537580B (en) The construction method of distribution network structure based on K means clusters
CN108923396B (en) A kind of short circuit current quick calculation method of multiterminal flexible direct current power grid
CN105356481B (en) A kind of dynamic passive compensation reconnaissance method based on more feed-in short-circuit ratioes
CN104821582B (en) Turned for optimization method and its system based on the distribution network load of nonlinear integer programming
CN108092266A (en) A kind of bulk power grid equivalence method suitable for electromagnetic transient simulation for considering zero sequence impedance
CN109638839B (en) Load flow calculation method of bipolar flexible direct-current transmission system
CN109659968B (en) Electromechanical transient modeling method for distributed access type LCC-MMC (lower control limit-multilevel converter) mixed direct-current system
Li et al. Research on power flow calculation method of true bipolar VSC-HVDC grids with different operation modes and control strategies
CN110489806B (en) Electromagnetic transient modeling and calculating method for power grid comprising multi-voltage-source converter
CN113158617B (en) General decoupling method and system for electromagnetic transient simulation of voltage source type converter
CN108388688A (en) A kind of active distribution network reliability estimation method
CN111668843A (en) Low-voltage distribution network three-phase load flow calculation method based on phase sequence mixing method
CN106655234A (en) Method for analyzing influence of line impedance and call wire power on generalized short-circuit ratio
CN113270868B (en) Dynamic load flow calculation method for power supply system of alternating current electrified railway train
CN103606946A (en) Power transmission system for promoting alternating current overhead line transmission capacity based on MMC
CN104573384B (en) A kind of improvement DC power flow algorithm suitable for power distribution network on-line analysis
CN105896558B (en) VSC-based UPFC electromechanical transient modular modeling method
CN110048427B (en) Multi-end flexible direct-current power distribution network power flow protection constant value calculation method
CN107800137B (en) A kind of UPFC electromechanical transient simulation method based on MMC
CN103390890B (en) Based on the distribution power flow analytical method of current distribution factor
CN109802418A (en) Partial electric grid electrical-magnetic model equivalence method suitable for extra-high voltage direct-current access
CN116054126A (en) Equivalent method of electrified railway through power supply system
CN110879915B (en) Method and system for external equivalence of power systems

Legal Events

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