CN112398103B - Protection method and device of direct current traction power supply system - Google Patents
Protection method and device of direct current traction power supply system Download PDFInfo
- Publication number
- CN112398103B CN112398103B CN202011345337.8A CN202011345337A CN112398103B CN 112398103 B CN112398103 B CN 112398103B CN 202011345337 A CN202011345337 A CN 202011345337A CN 112398103 B CN112398103 B CN 112398103B
- Authority
- CN
- China
- Prior art keywords
- current
- power supply
- supply section
- traction power
- feeder
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The application provides a protection method and a system of a direct current traction power supply system, wherein the current amplitudes of a positive feeder line and a negative feeder line at the local end of a direct current traction power supply section are acquired through a protection device configured on a positive feeder line switch, the current amplitudes of the positive feeder line and the negative feeder line at the opposite end of the direct current traction power supply section are acquired, and the protection device calculates the sum current in the direct current traction power supply section in real time. And when the calculated sum current is greater than the set protection action threshold value, the protection device judges the contact network grounding short circuit fault of the power supply section, trips the positive feeder switch of the local terminal, and sends a tripping signal to the opposite terminal protection device. The calculated sum current can directly reflect the size of the fault section of the direct-current traction power supply system and the current of the grounding branch, the influence of the load of the subway vehicle on protection judgment is effectively eliminated, the selectivity and the sensitivity of the protection on the judgment of the grounding short circuit fault of the contact network are improved, and the quick and accurate judgment of the fault section provides guarantee for the safe and reliable operation of the subway.
Description
Technical Field
The application relates to the field of protection of urban rail transit direct-current power supply systems, in particular to a protection method and device of a direct-current traction power supply system.
Background
The urban rail transit electric traction network is generally supplied with direct current and provides kinetic energy for subway vehicles, and comprises a contact network (anode) and a return network (cathode). At present, most traction networks of power supply systems of various urban rail transit systems in China adopt overhead contact networks or contact rails (third rails) to supply power to vehicles, and the power is reserved to traction substations through steel rails. In the power supply mode of taking the running rails as the reflux network, the traction reflux can enter the track bed through the steel rails to form stray current. Stray current will all corrode rail, whole railway roadbed structure reinforcing bar, tunnel structure reinforcing bar, bridge reinforcing bar and the metal equipment along the subway line, and then influence the life of each building structure and metal equipment along the subway line. In order to inhibit the influence of stray current corrosion, the traditional treatment method usually adopts various means such as increasing the insulation of a steel rail to the ground, arranging a stray current collecting net and the like, but cannot fundamentally solve the corrosion influence of the stray current, and along with the increase of the operation age of subways, the insulation impedance between the steel rail and the ground is gradually reduced due to the moisture, metal dust (brake shoe brake) and heavy pressing of a train body, the part of the stray current generated during the running of a vehicle flowing to a line is increased year by year, and the electrochemical corrosion phenomenon is more and more serious. In order to fundamentally solve the problem, a special 'return rail' is arranged on a traction network of a part of urban rail transit power supply systems to serve as a fourth rail, and the fourth rail is completely separated from a running rail of a locomotive, so that the problem of stray current corrosion protection is thoroughly solved.
Although the return rail and the running rail of the direct-current traction power supply system are completely separated, the problem of stray current corrosion protection can be effectively solved, when a grounding short circuit fault of a contact network (anode) occurs, the return rail and the running rail are completely independent, so that the fault current cannot flow to the return rail, larger fault current is difficult to generate, and a protection device arranged on a feeder switch cannot identify and remove the fault. Therefore, a direct-current traction power supply system with a return rail and a running rail completely separated is adopted, a grounding resistor with a smaller resistance value is usually configured on a negative bus of a direct-current traction substation to be connected with the ground, and the current generated when a contact network (positive electrode) is in a ground short circuit fault is increased. As is well known, a subway vehicle runs by taking electricity through a contact network (anode), and generates a large current in acceleration and deceleration processes, and an overcurrent action threshold of a protection device on a feeder switch is often high in order to avoid frequent false actions of the protection device on the feeder switch. Therefore, when a contact network (anode) is in a ground short circuit fault through a large resistor, the fault current flowing through the feeder switch still can not reach the overcurrent action threshold, so that the protection device cannot act. Meanwhile, a large potential difference is generated between the ground and the negative bus of the traction substation due to the fault current flowing through the ground resistor disposed on the negative bus of the traction substation, which causes simultaneous operation of leakage protection of voltage type frames for preventing insulation damage of equipment in a plurality of traction substations, resulting in large-area power failure of the traction power supply system.
The above information disclosed in this background section is only for enhancement of understanding of the background of the application and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
The application provides a protection method and a protection device for a direct-current traction power supply system, which can effectively eliminate the influence of subway vehicle load on protection judgment, improve the selectivity and sensitivity of protection on contact network ground short circuit fault judgment, and ensure safe and reliable operation of a subway by quickly and accurately judging a fault section.
The features and advantages of the present solution will become apparent from the following detailed description, or may be learned through practice of the present application.
According to an aspect of the present application, a protection method for a dc traction power supply system is provided, including:
the method comprises the following steps that an independent contact net and a return net are arranged in a direct current traction power supply system, a locomotive obtains direct current through the contact net and the return net, and the return net is completely independent and insulated from a traveling rail;
the positive bus is electrically connected with a contact network through a feeder switch, the negative bus is electrically connected with a return network through a negative feeder, and the negative bus is connected with the ground through a ground resistor;
the protection devices are arranged according to the number of the positive feeder switches, namely, each positive feeder switch is provided with 1 protection device, and the current of the positive feeder and the current of the corresponding negative feeder are collected;
the protection devices corresponding to the positive feeder lines of the adjacent traction power supply sections exchange information in real time;
and when the protection device detects that the sum current in the traction power supply section is greater than a set threshold value, judging that a contact network ground fault occurs in the traction power supply section, and tripping off the positive feeder switch and the adjacent positive feeder switch in the traction power supply section.
According to some embodiments, the protection device obtains the current of the positive feeder switch and the current flowing through the corresponding negative feeder in real time through the current collection unit, wherein the positive polarity end of the current collection unit installed on the positive feeder is close to the catenary, and the positive polarity end of the current collection unit installed on the negative feeder is close to the return current network.
According to some embodiments, the information exchanged in real-time comprises: the protection device collects current information of the positive feeder switch and corresponding negative feeder current information and is used for independently judging faults of the direct current traction power supply section by the protection devices at two ends of the direct current traction power supply section.
According to some embodiments, the information content exchanged in real-time comprises: synchronous abnormity detection of data at two ends of the direct-current traction power supply section, abnormity detection of a transceiving channel and sampling abnormity detection of a device at the opposite end of the direct-current traction power supply section, if any abnormity occurs, a contact network grounding fault judgment function of the protection device at the local end of the direct-current traction power supply section is rapidly withdrawn by self, and an abnormity alarm prompt is provided.
According to some embodiments, the sum current calculated by the protection device is the vector sum of the positive and negative feeder currents at the local end of the dc traction power supply section and the opposite end of the dc traction power supply section, as shown in formula 1:
Isum＝|Ionpos+Ionneg+Ioffpos+Ioffnegequation 1
Wherein the content of the first and second substances,
Isumis the sum current in the DC traction power supply section;
Ionposis the positive feed line current of the local end of the direct current traction power supply section;
Ionnegis the current of the negative feeder line at the local end of the direct current traction power supply section;
Ioffposis the positive feed line current of the opposite end of the direct current traction power supply section;
Ioffnegis the negative end feeder current of the direct current traction power supply section.
According to some embodiments, the current collecting unit of any one of the positive feeder line and the negative feeder line of the local end and the opposite end of the direct current traction power supply section is disconnected, the sum current calculated by the protection device is forced to be 0, and a feeder line current collecting unit disconnection prompt is provided.
According to some embodiments, the sum current calculated by the protection device in the non-fault traction power supply section tends to 0, and the sum current calculated by the protection device in the traction power supply section with the contact network ground fault is not 0 because the negative bus is grounded through the resistor.
According to some embodiments, when the sum current detected by the protection device in the direct current traction power supply section is larger than a set protection action threshold value, the protection device judges that the direct current traction power supply section is a fault section, and jumps out of the positive feeder circuit breaker, and sends out joint tripping information to the protection device at the opposite end of the direct current traction power supply section, so that the fault is cut off and isolated.
According to some embodiments, the protection action threshold may be derived based on the resistance of the ground resistor,
see equation 2:
wherein, IprotIs the protection action threshold;
K1is the reliability factor;
p is the rectifier capacity;
r is the resistance of the ground resistor.
According to some embodiments, the protection action threshold may be calculated as a braking current based on the load current, see equation 3:
Iprot＝K2×(|Ionpos|+|Ionneg|+|Ioffpos|+|Ioffneg|) equation 3
Wherein the meanings of the symbols are as follows:
Iprotis the protection action threshold;
K2is the braking coefficient;
Ionposis the positive feed line current of the local end of the direct current traction power supply section;
Ionnegis the negative feeder current at the local end of the direct current traction power supply section;
Ioffposis the positive feed line current of the opposite end of the direct current traction power supply section;
Ioffnegis the negative end feeder current of the direct current traction power supply section.
According to some embodiments, the protection action threshold may be calculated according to an action fixed value of the voltage-type frame leakage protection configured in the traction power supply section, as shown in formula 4:
Iprot＝K3x (U/R) formula 4
Wherein the meanings of the symbols are as follows:
Iprotis the protection action threshold;
K3is the reliability factor;
u is a voltage type frame leakage protection action threshold;
r is the resistance of the ground resistor.
According to another aspect of the present application, there is provided a protection device for a dc traction power supply system, including:
a positive bus and a negative bus provided by the direct current traction power supply section;
the locomotive obtains direct current through the contact network and the return network, and the return network is completely independent and insulated from the traveling rail;
a positive feeder switch and a negative feeder switch, wherein the positive bus is electrically connected with a contact net through the positive feeder switch, the negative bus is electrically connected with a return net through the negative feeder,
the grounding resistor is arranged between the negative bus and the ground;
the protection devices are arranged according to the number of the positive feeder switches, namely, each positive feeder switch is provided with 1 protection device, and the current of the positive feeder where the protection device is arranged and the current of the corresponding negative feeder where the protection device is arranged are collected;
the protection device obtains the current of the positive feeder switch and the current flowing through the corresponding negative feeder in real time through the current collection unit, wherein the positive polarity end of the current collection unit installed on the positive feeder is close to a contact net, and the positive polarity end of the current collection unit installed on the negative feeder is close to a return net.
According to the technical scheme, the sum current of the traction power supply section is calculated by acquiring the currents of the positive feeder line and the negative feeder line at the two ends of the traction power supply section through the protection device configured on the positive feeder line, and whether the contact network (positive pole) ground short circuit fault occurs in the traction power supply section is judged by comparing the sum current with a set protection action threshold value, so that the fault is correctly cut off and isolated. The scheme effectively solves the problems of insufficient protection selectivity and sensitivity of the existing direct-current traction power supply system with the return track and the walking track completely separated.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without exceeding the protection scope of the present application.
FIG. 1 is an architecture diagram of a DC traction power supply section according to an example embodiment;
FIG. 2 is an architecture diagram of a DC traction power supply system according to an example embodiment;
FIG. 3 is an equivalent topology of a DC traction power supply system according to an example embodiment;
fig. 4 is a logic diagram of a protection method of a dc traction power supply system according to an example embodiment.
Wherein the reference numerals illustrate:
107-positive bus, 109-negative bus, 121, 122-positive feeder, 110, 111-positive feeder switch, 112, 113-positive feeder current collection unit, 103-contact network, 117-negative bus ground resistance, 119-earth, 123, 124-negative feeder, 114, 115-negative feeder current collection unit, 105-reflux network; 210-a running rail, 250-a subway vehicle anode electricity-taking device, 230-a subway vehicle cathode electricity-taking device, 270-an information transmission channel, 201a, 202 b-a protection device on a positive feeder switch; 290-DC traction power supply section
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and a repetitive description thereof will be omitted.
The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other means, components, materials, devices, etc. In such cases, well-known structures, methods, devices, implementation steps, materials, or operations are not shown or described in detail.
Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The terms "first," "second," and the like in the description and claims of the present application and in the foregoing drawings are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.
Although the return current rail and the running rail of the direct current traction power supply system in the prior art are completely separated, the problem of stray current corrosion protection can be effectively solved, when a grounding short circuit fault of a contact network (anode) occurs, the return current rail and the running rail are completely independent, so that the fault current cannot flow to the return current network, a large fault current is difficult to generate, and a protection device arranged on a feeder switch cannot identify and remove the fault. Therefore, a direct-current traction power supply system with a return rail and a traveling rail completely separated is adopted, a grounding resistor with a smaller resistance value is usually configured on a negative bus of a direct-current traction substation to be connected with the ground, and the current generated when a contact network (positive electrode) is in a ground short circuit fault is increased. As is well known, a subway vehicle runs by taking electricity through a contact network (anode), and generates a large current in acceleration and deceleration processes, and an overcurrent action threshold of a protection device on a feeder switch is often high in order to avoid frequent false actions of the protection device on the feeder switch. Therefore, when a contact network (anode) is in a ground short circuit fault through a large resistor, the fault current flowing through the feeder switch still can not reach the overcurrent action threshold, so that the protection device cannot act. Meanwhile, the ground resistance arranged on the negative bus of the traction substation causes a large potential difference between the ground and the negative bus of the traction substation due to the fault current flowing through the ground resistance, and causes simultaneous operation of leakage protection of voltage-type frames for preventing insulation damage of equipment in the plurality of traction substations, thereby causing large-area power failure of the traction power supply system.
The technical solution of the present application will be described in detail below with reference to the accompanying drawings.
Fig. 1 is an architecture diagram of a dc traction power supply section.
Referring to fig. 1, according to an embodiment, an independent overhead line system 103 and a return network 105 are provided in a dc traction power supply system, a train 200 (fig. 2) obtains dc power through the overhead line system 103 and the return network 105, and the return network 105 is completely independent and insulated from a running rail 210 (fig. 2).
The positive bus 107 and the negative bus 109 are provided from the traction power supply section, the positive bus 107 is electrically connected to the overhead line system 103 through positive feeder switches 110 and 111 and positive feeders 121 and 122, the negative bus 109 is electrically connected to the return line 105 through negative feeders 123 and 124, and the negative bus 109 is connected to the ground 119 through a ground resistor 117.
The protection devices (for example, 201a in fig. 2) are arranged according to the number of the positive feeder switches, that is, 1 protection device is configured for each positive feeder switch to collect the current of the positive feeder and the current of the corresponding negative feeder. As shown in fig. 1, 1 protection device is respectively configured for the positive feeder switch 111 and the positive feeder switch 110, the protection device on the positive feeder switch 111 obtains the currents flowing through the current collecting units 113 and 115, and the protection device on the positive feeder switch 110 obtains the currents flowing through the current collecting units 112 and 114.
The protection devices configured on the positive feeder switches at both ends in the traction power supply section perform real-time exchange of information, which will be specifically described in fig. 2.
According to the embodiment, the protection device calculates the sum current in the tractive power supply section according to the acquired positive feeder current and negative feeder current at two ends of the tractive power supply section, and when the protection device detects that the sum current in the tractive power supply section is larger than a set threshold value, it is determined that a contact network 103 ground fault occurs in the tractive power supply section, and a positive feeder switch 111 in the tractive power supply section and a positive feeder switch (not shown in fig. 1) at the opposite end of the tractive power supply section are tripped.
According to an embodiment, the positive polarity ends of the current collection units 113, 112 mounted on the positive feed lines 121, 122, respectively, are close to the catenary 103, and the positive polarity ends of the current collection units 115, 114 mounted on the negative feed lines 123, 124, respectively, are close to the return current network 105.
The following describes in detail the real-time information exchange in the present application, and the protection devices at both ends of the dc traction power supply system transmit the collected positive and negative feeder current amplitude information and the inter-tripping signal between the protection devices in real time.
Theoretically, the sum current of the direct current traction power supply section where the protection device is located is 0 according to kirchhoff's current law, and the sum of the currents flowing into and out of any node is 0. The sum current can directly reflect the size of the fault section and the current of the ground circuit of the direct current traction power supply system. When a contact network grounding short circuit fault occurs in the power supply section, the sum current in the fault section is equal to the sum of currents flowing through the cathode bus grounding resistors in each traction power supply system. When the subway vehicle in the power supply section normally runs, the sum current in the operation section tends to 0. Therefore, whether the contact network in the power supply section has the ground short circuit fault can be judged only by calculating the sum current of the direct current traction power supply section.
Optionally, the protection devices may acquire the information in a peer-to-peer communication manner, or in a multi-device networking communication manner.
Compared with the traditional method that the fault is judged by adopting the current amplitude of the positive feeder line, the influence of the load current of the metro vehicle on protection judgment is completely filtered by adopting the fault and judging the fault by adopting the current, the fault section of the direct-current power supply traction system and the size of the ground short-circuit current can be reflected more sensitively, and the protection device is convenient to identify the fault section.
Fig. 2 is an architecture diagram of a dc traction power supply system, and fig. 3 is an equivalent topology diagram of the dc traction power supply system according to an example embodiment.
Referring to fig. 2 and fig. 3, the following embodiments are presented based on an equivalent topology diagram of a dc traction power supply system, but the equivalent topology diagram of the dc traction power supply system is only an implementation form of the idea of the present application, and the present application is also applicable to a power supply system structure similar to the above. The protection method for processing the grounding short circuit fault of the contact network comprises the following analysis:
referring to fig. 3, the traction power supply area, 300, is shown as a dashed box:
1) when the K point in FIG. 3 fails, the protection device disposed in B302 collects the positive feeder current I in the power supply sectionBCP2And negative feeder current IBCN2Is configured in the positive feed line current I collected by the C301 protection device in the power supply sectionCCP1And negative feeder current ICCN1The current amplitude of (2). The protection devices exchange the collected current data. The B302 and C301 protection devices respectively calculate the sum current I in the power supply sectionsumA value of | IBCP2+IBCN2+ICCP1+ICCN1L. When IsumThe current amplitude is larger than a set protection action threshold IprotThe B302 protection device judges that a contact network ground short circuit fault occurs in the power supply section, the B302 protection device acts, and a joint jump instruction is sent to an opposite-end protection device C301 of the power supply section; the C301 protection device judges that a contact network ground short circuit fault occurs in the power supply section, the C301 protection device acts, and a joint jump instruction is sent to the opposite-end protection device B302 of the power supply section, so that complete removal and isolation of the fault are achieved.
2) When a fault occurs at point K in fig. 3, the protection device configured in point a302 collects the current amplitudes of the positive feeder current IACP2 and the negative feeder current IACN2 in the power supply section, and the protection device configured in point B301 collects the current amplitudes of the positive feeder current IBCP1 and the negative feeder current IBCN1 in the power supply section. The protection devices exchange the collected current data. The A302 and B301 protection devices respectively calculate the sum current I in the power supply sectionsumOf value | IACP2+IACN2+IBCP1+IBCN1|。 IsumThe current amplitude is almost 0 and is smaller than the set protection action threshold IprotThe A302 and B301 protection devices do not act.
The sum current calculated by the protection device is the vector sum of the current of the positive and negative feeder lines at the local end of the direct current traction power supply section and the opposite end of the direct current traction power supply section, and is shown in formula 1:
Isum＝|Ionpos+Ionneg+Ioffpos+Ioffnegequation 1
Wherein the content of the first and second substances,
Isumis the sum current in the DC traction power supply section;
Ionposis the positive feed line current of the local end of the direct current traction power supply section;
Ionnegis the current of the negative feeder line at the local end of the direct current traction power supply section;
Ioffposis the positive feed line current of the opposite end of the direct current traction power supply section;
Ioffnegis the negative feeder current at the opposite end of the direct current traction power supply section.
The sum current calculated by the protection device in the non-fault traction power supply section approaches 0, and in detail, the sum current is infinitely close to 0 in practice but is just 0 as distinguished from the theoretical calculation. The sum current calculated by the protection device in the traction power supply section with the contact network ground fault is not 0 because the negative bus is grounded through the resistor.
According to some embodiments, the protection action threshold may be derived from the resistance of the ground resistor, as shown in equation 2:
wherein, IprotIs the protection action threshold;
K1is the reliability factor;
p is the rectifier capacity;
r is the resistance of the ground resistor.
According to some embodiments, the protection action threshold may be calculated as a braking current based on the load current, see equation 3:
Iprot＝K2×(|Ionpos|+|Ionneg|+|Ioffpos|+|Ioffnegi) formula 3
Wherein the meanings of the symbols are as follows:
Iprotis the protection action threshold;
K2is the braking coefficient;
Ionposis a direct current traction power supply section local feed forwardA line current;
Ionnegis the negative feeder current at the local end of the direct current traction power supply section;
Ioffposis the positive feed line current of the opposite end of the direct current traction power supply section;
Ioffnegis the negative feeder current at the opposite end of the direct current traction power supply section.
According to some embodiments, the protection action threshold may be calculated according to an action fixed value of the voltage-type frame leakage protection configured in the traction power supply section, as shown in formula 4:
Iprot＝K3x (U/R) formula 4
Wherein the meanings of the symbols are as follows:
Iprotis the protection action threshold;
K3is the reliability factor;
u is a voltage type frame leakage protection action threshold;
r is the resistance of the ground resistor.
Specifically, the protection action threshold is calculated according to the above formula as a basis for selection of the actual situation.
The above embodiments are only for explaining the technical idea of the present application, and the protection scope of the present application cannot be limited thereby, and the real-time exchange of information between protection devices in the protection scheme may be implemented by point-to-point communication between protection devices, or by a communication network constructed by cascading switches among multiple traction substations; the communication medium can adopt optical signals, electric signals and the like; the calculation method of the sum current depends on the arrangement of the polarity ends of the positive feeder line current collection unit and the negative feeder line current collection unit, and if the polarity ends of the positive feeder line current collection unit and the negative feeder line current collection unit are opposite, the subtraction method is adopted for calculating the sum current; the protection scheme can be used for a direct-current traction power supply system and a direct-current power transmission and distribution system. Any modification made on the basis of the technical scheme according to the technical idea provided by the application falls within the protection scope of the application.
Fig. 4 is a logic diagram of a protection method of a dc traction power supply system according to an example embodiment.
According to an embodiment, in S400, the protection function is engaged.
At S410, the sum current of the traction power supply section is detected. The information exchanged in real time includes: the protection device collects current information of the positive feeder switch and corresponding negative feeder current information and is used for independently judging faults of the direct current traction power supply section by the protection devices at two ends of the direct current traction power supply section.
The sum current calculated by the protection device in the non-fault traction power supply section approaches 0, and in detail, the sum current is infinitely close to 0 in practice but is just 0 as distinguished from the theoretical calculation. The sum current calculated by the protection device in the traction power supply section with the contact network ground fault is not 0 because the negative bus is grounded through the resistor.
In S411, when the protection device in the dc tractive power supply section detects that the sum current is greater than the set protection action threshold, and determines that the dc tractive power supply section is a fault section, the method enters S413 to trip off the positive feeder circuit breaker, and executes S415 to send out the trip information to the opposite-end protection device of the dc tractive power supply section, thereby implementing the removal and isolation of the fault.
According to the embodiment, in S420, the current acquisition unit of any feeder line of the current acquisition unit of the local feeder line and the opposite positive feeder line of the direct current traction power supply section is disconnected, the sum current calculated by the protection device is forced to be 0, the system enters S421, the feeder line current acquisition unit is provided with a disconnection prompt, and the protection function of S400 does not work.
At S430, the information content exchanged in real time includes: synchronous abnormal detection of data at two ends of the direct-current traction power supply section, abnormal detection of a receiving and sending channel and sampling abnormal detection of a device at the opposite end of the direct-current traction power supply section.
According to the embodiment, if any one of the abnormalities occurs, the system enters the step S431, the function of judging the grounding fault of the contact network of the protection device at the local end of the direct-current traction power supply section is rapidly withdrawn, an abnormality alarm prompt is provided, and the protection function of the step S400 does not work.
According to the embodiment of the application, according to the technical scheme of the application, the sum current of the traction power supply section is calculated by acquiring the currents of the positive feeder line and the negative feeder line at two ends of the traction power supply section through the protection device configured on the positive feeder line, and whether the contact network (positive electrode) ground short circuit fault occurs in the traction power supply section is judged by comparing the sum current with a set protection action threshold value, so that the fault is correctly cut off and isolated. The scheme effectively solves the problem that the existing direct-current traction power supply system with the return track and the walking track completely separated is insufficient in protection selectivity and sensitivity, and the fault section is rapidly and accurately judged to provide guarantee for safe and reliable operation of the subway.
The foregoing embodiments have been described in detail to illustrate the principles and implementations of the present application, and the foregoing embodiments are only used to help understand the method and its core idea of the present application. Meanwhile, according to the idea of the present application, a person skilled in the art may make changes or modifications based on the specific embodiments and the application range of the present application, and all of them belong to the protection scope of the present application. In view of the above, the description should not be taken as limiting the application.
Claims (8)
1. A protection method of a direct current traction power supply system is characterized by comprising the following steps:
the method comprises the steps that an independent contact net and a return net are arranged in a direct current traction power supply system, a locomotive obtains direct current through the contact net and the return net, the return net is completely independent and insulated from a walking rail, the contact net is a positive pole, and the return net is a negative pole;
the positive bus is electrically connected with the contact net through a feeder switch, the negative bus is electrically connected with the return net through a negative feeder, and the negative bus is connected with the ground through a ground resistor;
the protection devices are arranged according to the number of the positive feeder switches, and collect the current of the positive feeder and the current of the corresponding negative feeder;
the protection devices configured on the positive feeder switches at the two ends in the traction power supply section exchange information in real time;
the protection device calculates the sum current in the traction power supply section according to the acquired positive and negative feeder currents at the local end of the traction power supply section and the positive and negative feeder currents at the opposite end of the traction power supply section, and when the sum current detected by the protection device is larger than a set protection action threshold value, the protection device judges that a contact network ground fault occurs in the traction power supply section and trips off the positive feeder switches at the local end and the opposite end in the traction power supply section;
the sum current calculated by the protection device is the vector sum of the current of the positive feeder line and the current of the negative feeder line of the local end of the tractive power supply section and the current of the positive feeder line and the negative feeder line of the opposite end of the tractive power supply section, and the sum current is shown in a formula 1:
Isum＝|Ionpos+Ionneg+Ioffpos+Ioffnegequation 1
Wherein the content of the first and second substances,
Isumis a sum current within the traction power supply section;
Ionposis the positive feed line current of the local end of the traction power supply section;
Ionnegis the negative feeder current at the local end of the traction power supply section;
Ioffposis the positive feed line current to the opposite end of the traction power supply section;
Ioffnegis the negative end-to-end feeder current of the traction power supply section;
the protection action threshold value can be obtained according to the resistance value of the grounding resistor, and is shown in a formula 2:
wherein, IprotIs the protection action threshold;
K1is the reliability factor;
p is the rectifier capacity;
r is the resistance of the ground resistor;
alternatively, the protection action threshold may be calculated based on the load current as the braking current, as shown in equation 3:
Iprot＝K2×(|Ionpos|+|Ionneg|+|Ioffpos|+|Ioffnegi) formula 3
Wherein the meanings of the symbols are as follows:
K2is the braking coefficient;
alternatively, the protection action threshold may be calculated according to an action fixed value of the voltage-type frame leakage protection configured in the traction power supply section, as shown in formula 4:
Iprot＝K3x (U/R) formula 4
Wherein the meanings of the symbols are as follows:
K3is the reliability factor;
u is the voltage frame leakage protection action threshold.
2. The protection method according to claim 1, characterized in that: the protection device obtains the current of the positive feeder switch and the current flowing through the corresponding negative feeder in real time through the current collection unit, wherein the positive polarity end of the current collection unit installed on the positive feeder is close to a contact net, and the positive polarity end of the current collection unit installed on the negative feeder is close to a return net.
3. Protection method according to claim 1, characterized in that said information exchanged in real time comprises:
the protection device collects current information of the positive feeder switch and corresponding negative feeder current information, and is used for the protection device at two ends of the traction power supply section to independently judge faults of the traction power supply section.
4. Protection method according to claim 3, characterized in that said information exchanged in real time comprises:
and if any one of the abnormal conditions occurs, the function of judging the grounding fault of the contact net of the local protection device of the traction power supply section is automatically and rapidly withdrawn, and an abnormal alarm prompt is provided.
5. The protection method according to claim 1, wherein the current collection unit of any one of the feeder lines of the local end and the opposite end of the tractive power supply section is disconnected, the sum current calculated by the protection device is forced to be 0, and a feeder line current collection unit disconnection prompt is provided.
6. The protection method according to claim 1, wherein the sum current calculated by the protection device in the non-fault traction power supply section tends to 0, and the sum current calculated by the protection device in the traction power supply section in which the overhead contact system ground fault occurs is not 0 because the negative bus is grounded via the resistor.
7. The protection method according to claim 1, wherein the protection device in the tractive power supply section detects that the sum current is greater than the set protection action threshold, determines that the tractive power supply section is a fault section, trips off a positive feeder circuit breaker, and sends out tripping information to an opposite-end protection device of the tractive power supply section to cut off and isolate a fault.
8. A protection system for a dc traction power supply system, comprising:
the traction power supply section provides a positive bus and a negative bus;
the locomotive traction power supply system comprises a contact network and a return network which are independently arranged in a direct current traction power supply system, wherein a locomotive obtains direct current through the contact network and the return network, and the return network is completely independent and insulated from a travelling rail;
the positive bus is electrically connected with the contact network through the positive feeder switch, the negative bus is electrically connected with the return network through the negative feeder,
the grounding resistor is arranged between the negative bus and the ground;
the protection devices are arranged according to the number of the positive feeder switches and are used for collecting the current of the positive feeder and the current of the corresponding negative feeder;
the protection device obtains the current of the positive feeder switch and the current flowing through the corresponding negative feeder in real time through the current collection unit, wherein the positive polarity end of the current collection unit installed on the positive feeder is close to a contact net, and the positive polarity end of the current collection unit installed on the negative feeder is close to a return net.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011345337.8A CN112398103B (en) | 2020-11-25 | 2020-11-25 | Protection method and device of direct current traction power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011345337.8A CN112398103B (en) | 2020-11-25 | 2020-11-25 | Protection method and device of direct current traction power supply system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112398103A CN112398103A (en) | 2021-02-23 |
| CN112398103B true CN112398103B (en) | 2022-07-22 |
Family
ID=74605208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011345337.8A Active CN112398103B (en) | 2020-11-25 | 2020-11-25 | Protection method and device of direct current traction power supply system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112398103B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112803381B (en) * | 2021-03-10 | 2022-04-08 | 清华大学 | Contact net differential protection method and device of full-through type flexible traction power supply system |
| CN113036728B (en) * | 2021-03-17 | 2022-07-12 | 济宁华源热电有限公司 | Railway electric power transmission device |
| CN114167307B (en) * | 2021-12-09 | 2024-04-30 | 重庆中车长客轨道车辆有限公司 | Ground fault detection system and method for straddle type monorail vehicle |
| CN114475370B (en) * | 2022-03-14 | 2023-04-07 | 西南交通大学 | Short circuit sectional protection method for contact network of cable through power supply system |
| ES2924781B2 (en) * | 2022-04-12 | 2023-02-20 | Adif Alta Velocidad | SYSTEM FOR THE DETECTION OF DEFECTS IN RAILWAY ELECTRICAL SUPPLY INSTALLATIONS AND PROCEDURE FOR SUCH SYSTEM |
| CN115425673B (en) * | 2022-11-07 | 2023-02-17 | 清华大学 | Flexible direct-current traction power supply and reflux system comprehensive high-efficiency load flow calculation method thereof |
| CN116599059B (en) * | 2023-07-17 | 2023-09-19 | 中国铁路设计集团有限公司 | Multi-source traction power supply system fault section discrimination and power supply optimization method and device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102306931B (en) * | 2011-09-15 | 2013-12-25 | 北京四方继保自动化股份有限公司 | Direct-current traction feed section region protection system and protection method |
| CN109149536A (en) * | 2017-07-06 | 2019-01-04 | 天津中铁电气化设计研究院有限公司 | A kind of DC power-supply system Traction networks ground protection mode that positive and negative anodes insulate |
-
2020
- 2020-11-25 CN CN202011345337.8A patent/CN112398103B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112398103A (en) | 2021-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112398103B (en) | Protection method and device of direct current traction power supply system | |
| RU2664621C1 (en) | Distributed protection system for the segmented power network on the electrified railway | |
| CN107351730B (en) | Automatic neutral section passing system without power failure of electrified railway train and operation method thereof | |
| KR100766365B1 (en) | delta;I GROUND FAULT PROTECTIVE RELAYING SYSTEM AND CONTROL METHOD IN DC TRACTION POWER SUPPLY SYSTEM | |
| US7683558B2 (en) | Electric car control apparatus | |
| CN103311910A (en) | Direct current traction power supply system and protective method | |
| CN110605999B (en) | Measurement and control protection system and method for through type in-phase power supply network | |
| CN100414800C (en) | Travelling wave identification method of superhigh voltage DC line fault | |
| CN108134378A (en) | A kind of DC protection system and direct current protecting implementation method | |
| KR100696984B1 (en) | Pilot ground fault protective relaying scheme in traction power supply system | |
| CN113253058B (en) | Method and system for ranging fault of contact network of direct-current traction power supply system | |
| CN103213604A (en) | Train position detection system and method for automatic passing over of neutral section on ground for high speed railway for passenger traffic | |
| CN206452103U (en) | A kind of frame protection device for metro traction power system | |
| CN110687401A (en) | Fault detection system and method for overhead contact system on railway | |
| CN109193595B (en) | Active power distribution network failure separation method based on current phase comparison | |
| CN217994213U (en) | Multi-system traction power supply system | |
| CN111835082A (en) | Intelligent control method for fault self-healing of subway direct-current traction power supply system | |
| CN108075450B (en) | A kind of guard method and protective device for direct current suspension power supply system | |
| CN103208787A (en) | Mixed line self-adaption reclosing based on fault direction distinguishing principle | |
| JPH05172892A (en) | Fault location system on dc parallel feeder circuit of electric railway | |
| CN205509587U (en) | Segmentation track charging system | |
| CN210792876U (en) | Measurement and control protection system of through-type in-phase power supply network | |
| CN108281945A (en) | It is a kind of based on the singlephase earth fault shielding system and partition method of applying signal outside | |
| CN215116702U (en) | Monopole short-circuit fault monitoring device | |
| CN102211531B (en) | Method for confirming one-phase multipoint ground fault of long stator |
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 |