CN102025152B - Electric energy quality evaluation method of electrified railway accessed power system - Google Patents
Electric energy quality evaluation method of electrified railway accessed power system Download PDFInfo
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Abstract
The invention relates to the technical field of the electrified railway, in particular to an electric energy quality evaluation method of an electrified railway accessed power system. The electric energy quality evaluation method adopts the following technical scheme: (1) the invention aims at obtaining a negative sequence computing method which is suitable for building single-phase load simulation of the electrified railway in power system simulation software (PSD) which is generally used in power systems, and (2) the invention aims at obtaining a method that is used for calculating the current value, which is allowed to be injected in the electrified railway by a point of common coupling, of the harmonic wave at each order in the power system in which the electrified railway traction station is accessed by way of T-type wiring. In the invention, system evaluation simulation calculation is carried out on the related problems of the electric energy quality of the electrified railway, the analysis and evaluation of related problems of the electric energy quality are provided, so as to give guiding suggestions to the design, compensation and fixed value selection and the like of the electrified railway and the corresponding power supply system.
Description
Technical field
The present invention relates to the electric railway technical field, specifically relate to apply to before electrified railway engineering puts into operation, the part throttle characteristics of assessment electric railway is to the influence degree of the indexs such as power system voltage and harmonic wave, in order to arrange the evaluates calculation method of a kind of electric railway access electric power quality index of control measures before operation of engineering projects.
Background technology
[0002] electric railway dynamical system mainly comprises electric power system and trailer system.Because non-linear, single-phase, the impact characteristics of electric locomotive load, the development of electric railway bring certain impact can for the local electrical network quality of power supply.Only have and the electrified railway electric energy quality relevant issues are carried out system in depth study, provide quality of power supply Analysis on Issues Related and assessment, could provide the suggestion with directive significance to the design of electric railway and corresponding electric power system, compensation, definite value selection etc.
The electrified railway electric energy quality problem generally includes negative phase-sequence, two aspects of harmonic wave.Generating set abnormal heating and vibration near negative sequence component may cause.Negative sequence component can cause the threephase asynchronous service conditions to worsen, and produces brake torque, difficulty in starting etc.The negative sequence component that exceeds standard also may cause the protection malfunction; Harmonic problem then can be to because the reasons such as harmonic wave amplification may cause reactive power compensation normally to move, the power supply unit abnormal heatings such as generator, transformer, and protection malfunction and automation equipment are malfunctioning, also can cause the interference to communication system.
At present, the degree that the assessment electric railway is disturbed the negative phase-sequence of electric power system is mainly calculated the ratio that the negative phase-sequence capacity accounts for power system capacity, should not assess by power system simulation software.The electric network composition difference of electric railway electric power system along the line is larger, power taking voltage may be different, the system short circuit capacity significant difference, and with may have regional power plant or transformer station from the position of traction substation electrical distance close to, the negative phase-sequence capacity not only with the traction load Horizontal correlation, also closely related with the main electrical scheme of traction substation.Therefore, be necessary and power system simulation software assessed by negative phase-sequence interference level degree.
In addition, for the situation of Traction Station as the terminal station operation, in the GB clear common point allow the computational methods of its harmonic electric current, but the operational mode for Traction Station T connecting system, do not have clear in the GB, more and more be widely used in the electric railway access system plan and T connects mode, be necessary it is studied.
Summary of the invention
(1) the objective of the invention is to obtain a kind of negative phase-sequence computational methods that are fit to the emulation of electric railway single-phase load of in the general power system simulation software of electric power system (PSD), setting up.
(2) the objective of the invention is to obtain a kind of electric railway traction station that is adapted at and adopt in the T-shaped mode of connection access electric power system, calculate the method that points of common connection allows the individual harmonic current value of electric railway injected system.
The technical solution adopted for the present invention to solve the technical problems is:
(1) traction transformer of supposing the electric railway traction station is single-phase transformer, as shown in Figure 1, establishes I1, and I2 represents respectively the electric current that flows through on two draft arms, and IA, IB, IC represent because the phase current that load current causes in system.As seen from Figure 1, between A, the B phase in the Traction Station load connecting system three-phase, i.e. the alternate existence owing to single-phase load of AB has three-phase current I and flows through.Emulation in power system simulation software (PSD) is because the caused negative sequence voltage situation of single-phase load, can adopt two-phase generation phase fault to simulate, among the PSD schematic diagram of two-phase short-circuit fault as shown in Figure 2, wherein Z represents the impedance of phase fault.From the contrast of Fig. 1 and Fig. 2 as seen, as long as calculate the impedance Z of phase fault, just can simulate the single-phase load of electric railway.
In the process of asking for the phase fault impedance Z, need to be applied to following computing formula:
（2）
In formula (1)～(3), S is single-phase load power (MW),
Be respectively the load current (A) of supply arm,
Be the rated voltage (kV) of supply arm, P is single-phase load active power (MW), and Q is single-phase load reactive power (Mvar),
Be the single-phase load power-factor angle;
By formula (1)～(3), can according to supply arm electric current and the voltage of known conditions, calculate active power and the reactive power of single-phase load.Application of formula (4) and (5) can calculate the famous value of short-circuit impedance Z, and application of formula (6) and (7) can calculate the per unit value of short-circuit impedance Z.
In formula (4), (5),
With
Be respectively the famous value of resistance and the inductance of short-circuit impedance Z,
Rated voltage for the A of system, B, C three-phase side;
（6）
In formula (6), (7),
With
Be respectively the resistance of short-circuit impedance Z and the per unit value of inductance,
Be system's reference capacity;
Also should be noted that a bit, calculate by formula (1)～(7)
With
, contrast Fig. 2 should be 2 times short-circuit impedance value, therefore in the PSD software emulation, need with
With
All get 1/2 as the parameter of filling in the fault card.
(2) for i the user's in points of common connection place h subharmonic current permissible value (
) computational methods, can require according to the C3 of appendix C in " GB_T_14549-1993 " calculate, as follows:
（8）
In the formula (8):
-press the h subharmonic current permissible value after the points of common connection actual short capacity conversion, A;
Table 1 phase place is fallen and is added the coefficient value table
 |
3 | 5 | 7 | 11 | 13 | 9|〉the 13| even |
 |
1.1 | 1.2 | 1.4 | 1.8 | 1.9 | 2 |
When calculating allowable harmonic current,
With
Value be key factor, relevant with the mode of Traction Station access points of common connection, specifically can be with reference to the appendix B of " GB_T_12326-2008 ".
Solved by the inventionly be, the interconnection of two supply stations of Traction Station T access, and access point is in the transformer medium voltage side situation of supply station,
With
The Practical algorithm of value because for there is no elaboration in this situation GB, and can infer the interconnection situation of two even two supply stations of a plurality of Traction Station T access thus.
In the case, the allowable harmonic current of two supply stations needs to calculate respectively, supposes that on the interconnection of Traction Station A access supply station B and supply station C, the h subharmonic permissible value for Traction Station A injection points of common connection B and C can calculate with following formula so:
In the formula:
With
-press the h subharmonic current permissible value after the conversion of supply station B and C actual short capacity, A;
A kind of electric energy quality evaluation method of electrified railway accessed power of the present invention has following beneficial effect compared with prior art: the present invention is by carrying out the system evaluation analog computation to the electrified railway electric energy quality relevant issues, provide quality of power supply Analysis on Issues Related and assessment, the design of electric railway and corresponding electric power system, compensation, definite value selection etc. are provided the suggestion with directive significance.
Characteristics of the present invention are to have simplified the model buildings when the negative phase-sequence index is estimated; The interconnection of two supply stations of Traction Station T access, and access point is in the transformer medium voltage side situation of supply station,
With
The Practical algorithm of value because for there is no elaboration in this situation GB, and can infer the interconnection situation of two even two supply stations of a plurality of Traction Station T access thus.
Description of drawings
Fig. 1 is that the traction transformer at electric railway traction station is the schematic diagram of single-phase transformer;
Fig. 2 is the schematic diagram of two-phase short-circuit fault in the PSD software.
Embodiment
Below in conjunction with drawings and Examples to further instruction of the present invention.
(1) calculates the negative phase-sequence index
For Lanxi County's lattice electric railway, the implementation process take access Ledu, A Lan Traction Station supply station as the calculating of example explanation negative phase-sequence.The supply arm electric current of A Lan Traction Station and power-factor angle substitution formula (1)～(3) of locomotive load are obtained the performance number of locomotive load, again performance number substitution formula (4)～(7) are obtained the short-circuit impedance value.
（3）
（5）
With the short-circuit impedance that obtains
With
All get the 1/2 fault card (LS card) of inserting in the PSD software as follows:
LS ALAN 121 LEDUQ 121 9 5 2.13 1.03 2 6 2
LS ALAN 121 LEDUQ 121 -9 200 2.13 1.03 2 6 2
Fault card above adopting just can calculate the negative phase-sequence index that the A Lan Traction Station causes at the Ledu supply station.
(2) the allowable harmonic current computational methods of the T-shaped access scheme in Traction Station
With regard to Lanxi County's lattice electric railway, Ha Er lid Traction Station injects the change of points of common connection jewel and the spring Ji becomes 3 subharmonic current permissible values as example to calculate, and illustrates that T connects scheme allowable harmonic current computational methods.On Ha Er lid Traction Station access jewel transformer station and the lucky transformer station of the spring interconnection, jewel change and spring Ji are become by 3 subharmonic permissible values after the conversion of actual short capacity
,
, Ha Er lid Traction Station electricity consumption protocol capacity
, jewel becomes and the lucky main transformer capacity that becomes of spring
,
Substitution (7)～(8) formula obtains the traction of Ha Er lid and becomes the jewel change of injection points of common connection and the lucky harmonic wave permissible value that becomes of spring.
Calculate gained
For injecting jewel, Ha Er lid Traction Station becomes 3 subharmonic current permissible values,
For injecting the lucky 3 subharmonic current permissible values that become of spring in Ha Er lid Traction Station.
Claims (1)
1. electric energy quality evaluation method of electrified railway accessed power, it is characterized in that: described appraisal procedure comprises the steps:
1) traction transformer of supposing the electric railway traction station is single-phase transformer, establishes I
1, I
2Represent that respectively the electric current that flows through on two draft arms, IA, IB, IC represent because the phase current that load current causes in system; Between A, the B phase in the Traction Station load connecting system three-phase, i.e. the alternate existence owing to single-phase load of AB has three-phase current I and flows through; Emulation in power system simulation software PSD is because the caused negative sequence voltage situation of single-phase load adopts two-phase generation phase fault to simulate, and Z represents the impedance of phase fault among the PSD; As long as calculate the impedance Z of phase fault, just can simulate the single-phase load of electric railway;
Ask for the computing formula of phase fault impedance Z:
（2）
In formula (1)～(3), S is single-phase load power MVA, I
1, I
2Be respectively the electric current A of two draft arms,
Be the rated voltage kV of draft arm, P is single-phase load active power MW, and Q is single-phase load reactive power Mvar,
Be the single-phase load power-factor angle;
By formula (1)～(3), according to draft arm electric current and the voltage of known conditions, calculate active power and the reactive power of single-phase load; Application of formula (4) and (5) calculate the famous value of short-circuit impedance Z, and application of formula (6) and (7) calculate the per unit value of short-circuit impedance Z;
In formula (4), (5),
With
Be respectively the famous value of resistance and the inductance of short-circuit impedance Z,
Rated voltage for the A of system, B, C three-phase side;
In formula (6), (7),
With
Be respectively the resistance of short-circuit impedance Z and the per unit value of inductance,
Be system's reference capacity;
Calculate by formula (1)～(7)
With
, be 2 times short-circuit impedance value, in the PSD software emulation, need with
With
All get 1/2 as the parameter of filling in the fault card;
2) for i the user's in points of common connection place h subharmonic current permissible value (
) computational methods, require to calculate according to the C3 of appendix C in " GB_T_14549-1993 ", as follows:
In the formula (8):
-press the h subharmonic current permissible value after the points of common connection actual short capacity conversion, A;
In the case, the allowable harmonic current of two supply stations needs to calculate respectively, supposes that on the interconnection of Traction Station A access supply station B and supply station C, the h subharmonic permissible value for Traction Station A injection supply station B and supply station C calculates with following formula so:
（9）
In the formula:
With
-press the h subharmonic current permissible value after the conversion of supply station B and C actual short capacity, A;
The electricity consumption protocol capacity of-Traction Station A, value are the working capacity of traction transformer, MVA;
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| CN102243477B (en) * | 2011-06-17 | 2015-08-19 | 河南省电力公司信阳供电公司 | Based on the traction load modeling method of equivalent fault conversion |
| CN102340142B (en) * | 2011-09-22 | 2013-07-03 | 绍兴电力局 | Harmonic injection quantitative analytical method for multiple nonlinear users |
| CN102998980B (en) * | 2012-11-13 | 2016-07-20 | 中国电力科学研究院 | A kind of electric railway traction power supply system real-time simulation modeling method |
| CN102981075A (en) * | 2012-11-22 | 2013-03-20 | 江苏省电力公司电力科学研究院 | Monitoring system of power quality recording data of high-speed electrified railway |
| CN106356876B (en) * | 2016-09-08 | 2019-01-25 | 国网吉林省电力有限公司延边供电公司 | The negative-sequence current computation model of electric system is injected under high-speed rail AT power supply mode |
| CN106651168B (en) * | 2016-12-16 | 2021-02-02 | 华北电力科学研究院有限责任公司 | Method and device for evaluating influence of electric iron on power grid |
| CN107657398A (en) * | 2017-11-09 | 2018-02-02 | 国网西藏电力有限公司电力科学研究院 | The computational methods that a kind of power network quality of power supply influences |
| CN112677831B (en) * | 2019-10-17 | 2023-03-24 | 中铁二院工程集团有限责任公司 | Gridding power supply method applied to multi-line electrified railway |
| CN111308179A (en) * | 2019-12-19 | 2020-06-19 | 中铁二院工程集团有限责任公司 | Novel power factor calculation method for electrified railway |
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| DE10006844B3 (en) * | 2000-02-16 | 2004-02-12 | Jian, Xie, Prof.Dr.-Ing. | Controlling fixed position local converters supplying high voltage at special low frequency to railway system, measures phase angle from harmonic |
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