CN109782129B

CN109782129B - Ground fault point positioning method and device for rail transit traction auxiliary converter

Info

Publication number: CN109782129B
Application number: CN201910067538.7A
Authority: CN
Inventors: 刘洋; 高吉磊; 赵震; 张义海; 卜丽东; 刘伟志; 左鹏; 殷振环; 谢冰若; 刘佳璐
Original assignee: China Academy of Railway Sciences Corp Ltd CARS; Locomotive and Car Research Institute of CARS; Beijing Zongheng Electromechanical Technology Co Ltd
Current assignee: China Academy of Railway Sciences Corp Ltd CARS; Locomotive and Car Research Institute of CARS; Beijing Zongheng Electromechanical Technology Co Ltd
Priority date: 2019-01-24
Filing date: 2019-01-24
Publication date: 2024-05-10
Anticipated expiration: 2039-01-24
Also published as: CN109782129A

Abstract

The application provides a method and a device for positioning a ground fault point of a rail transit traction auxiliary converter, wherein the method comprises the following steps: after the connection between the inverter side and the ground detection circuit is broken, determining whether a ground fault occurs in the inverter side or a traction motor connected to the inverter side based on a result of comparing a target voltage ratio of the traction auxiliary converter, which has been determined to have the ground fault, with a first preset range; if not, according to the comparison result between the target voltage ratio and the second preset range and the third preset range, judging whether the ground fault occurs at the negative pole or the positive pole of the direct current link at the rectifying side, and if the ground fault does not occur at the negative pole or the positive pole of the direct current link at the rectifying side and the ground voltage has an alternating current component, positioning the ground fault at the secondary side of the traction transformer between the traction transformer and the rectifying side. The application can automatically and quickly locate the ground fault of the traction auxiliary converter, and the locating process has high accuracy.

Description

Ground fault point positioning method and device for rail transit traction auxiliary converter

Technical Field

The application relates to the technical field of rail transit, in particular to a method and a device for positioning a ground fault point of a rail transit traction auxiliary converter.

Background

Ground detection of power electronics is an important technology, relating to equipment and personnel safety. At present, a traction auxiliary converter of a locomotive or a motor train unit in a rail transit vehicle is usually arranged between a traction transformer and a traction motor of the locomotive or the motor train unit, wherein a grounding detection circuit is arranged between a rectifying side and an inverting side of the traction auxiliary converter, and is usually composed of two voltage dividing resistors connected in series between a positive busbar and a negative busbar of a direct current link of the rectifying side and a filter capacitor connected in parallel to two ends of the negative busbar resistor, wherein the middle point of the two voltage dividing resistors is grounded, and the voltage between a detection grounding point and the negative busbar is used as grounding voltage.

In the prior art, whether the traction auxiliary converter has a ground fault is detected by arranging the ground detection circuit, and the specific operation process is as follows: when the traction auxiliary converter works normally, the ratio of the grounding voltage to the direct-current link voltage is basically maintained at a certain constant value, and the value is determined by a voltage dividing resistor; when the traction auxiliary converter has a ground fault, the ratio deviates from the original constant value, and if the ratio is detected to deviate from the original constant value, the current traction auxiliary converter is judged to have the ground fault.

However, due to the complicated internal structure of the traction auxiliary converter, numerous components and parts and the like, even if the ground fault of the traction auxiliary converter is known, if the fault is found, a great amount of complicated and time-consuming manual investigation is needed, during the investigation, due to the time-consuming process of the investigation process, the serious damage of equipment in a short time is easy to occur, so that the equipment loss is brought, the normal operation of rail transit vehicles is even affected, and the requirements of modern railways on intellectualization and safety cannot be met. That is, the existing ground fault positioning method of the traction auxiliary converter needs to manually find the fault location after determining that the fault occurs, so that the problems of long time consumption, large workload, easy damage of fault equipment and the like of the fault positioning are solved.

Disclosure of Invention

Aiming at the problems in the prior art, the application provides the method and the device for positioning the ground fault point of the rail transit traction auxiliary converter, which can automatically and rapidly position the ground fault of the traction auxiliary converter, and the positioning process has high accuracy, so that the maintenance efficiency of fault equipment can be effectively improved, and the operation safety and reliability of the traction auxiliary converter are effectively improved.

In order to solve the technical problems, the application provides the following technical scheme:

In a first aspect, the present application provides a method for positioning a ground fault point of a traction auxiliary converter for rail transit, wherein a ground detection circuit is arranged between a rectifying side and an inverting side of the traction auxiliary converter, and the rectifying side is connected with a traction transformer of a rail transit vehicle, the method comprising:

After the connection between the inversion side and the grounding detection circuit is disconnected, judging whether the grounding fault occurs on the inversion side or a traction motor connected to the inversion side according to a comparison result of a target voltage ratio of the traction auxiliary converter, which is determined to have the grounding fault, and a first preset range, wherein the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a grounding voltage corresponding to the grounding detection circuit and a direct-current link voltage of the rectification side;

if not, judging whether the ground fault occurs in the direct current link cathode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range, and judging whether the ground fault occurs in the direct current link anode of the rectifying side according to a comparison result between the target voltage ratio and a third preset range;

If the ground fault is judged to be not generated at the negative pole or the positive pole of the direct current link of the rectifying side, whether the alternating current component exists in the ground voltage is further judged, and if the alternating current component exists in the ground voltage, the ground fault is positioned at the secondary side of the traction transformer between the traction transformer and the rectifying side.

Further, before the determining whether the ground fault occurs at the inverter side or the traction motor connected to the inverter side, further includes:

Acquiring the initial voltage ratio of the current traction auxiliary converter;

performing low-pass filtering on the initial voltage ratio to obtain a target voltage ratio of the current traction auxiliary converter;

and judging whether the target voltage ratio of the current traction auxiliary converter is within the first preset range, and if not, determining that the current traction auxiliary converter has a ground fault.

Further, an auxiliary converter is also connected to the traction auxiliary converter;

after the determining that the current traction auxiliary converter has a ground fault and before the determining whether the ground fault has occurred on the inverter side or a traction motor connected to the inverter side, further comprising:

disconnecting the auxiliary current transformer from the traction auxiliary current transformer;

Judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the first preset range;

If not, the connection between the inversion side and the grounding detection circuit is disconnected.

Further, the method further comprises the following steps:

and if the target voltage ratio of the traction auxiliary converter determined to have the ground fault is within the first preset range, positioning the ground fault at the auxiliary converter.

Further, the determining whether the ground fault occurs in the inverter side or the traction motor connected to the inverter side according to a comparison result of the target voltage ratio of the traction auxiliary converter determined to have the ground fault with the first preset range, includes:

If so, locating the ground fault at the inverter side or a traction motor connected to the inverter side.

Further, the determining whether the ground fault occurs in the dc link negative electrode of the rectifying side according to the comparison result between the target voltage ratio and the second preset range includes:

judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the second preset range;

if yes, positioning the grounding fault at the direct current link cathode of the rectifying side.

Further, the determining whether the ground fault occurs in the positive pole of the dc link at the rectifying side according to the comparison result between the target voltage ratio and the third preset range includes:

If the target voltage ratio is not within the second preset range, continuing to judge whether the target voltage ratio of the traction auxiliary converter determined to have the ground fault is within the third preset range;

if yes, positioning the ground fault at the direct current link positive electrode of the rectifying side.

Further, the method further comprises the following steps:

and if the ground voltage is further judged to have no alternating current component, positioning the ground fault at the positive pole of the direct current link at the rectifying side.

In a second aspect, the present application provides a ground fault point positioning device for a rail transit traction auxiliary converter, wherein a ground fault detection circuit is arranged between a rectifying side and an inverting side of the traction auxiliary converter, and the rectifying side is connected with a traction transformer of a rail transit vehicle, the device comprises:

the inverter ground fault judging module is used for judging whether the ground fault occurs on the inverter side or a traction motor connected to the inverter side according to a comparison result of a target voltage ratio of the traction auxiliary converter, which is determined to have the ground fault, and a first preset range after the connection between the inverter side and the ground detection circuit is disconnected, wherein the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a ground voltage corresponding to the ground detection circuit and a direct current link voltage of the rectifying side;

a dc link ground fault judging module, configured to judge whether the ground fault occurs in a dc link negative electrode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range, and judge whether the ground fault occurs in a dc link positive electrode of the rectifying side according to a comparison result between the target voltage ratio and a third preset range, if the ground fault does not occur in the inverting side;

And the secondary side grounding fault judging module of the transformer is used for further judging whether the grounding voltage has an alternating current component or not if the judgment shows that the grounding fault does not occur at the negative electrode or the positive electrode of the direct current link of the rectifying side, and if so, positioning the grounding fault at the secondary side of the traction transformer between the traction transformer and the rectifying side.

In a third aspect, the present application provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the ground fault point positioning method of the rail transit traction auxiliary converter when executing the program.

As can be seen from the above technical solution, the embodiment of the present application provides a method for positioning a ground fault point of a rail transit traction auxiliary converter, which includes determining whether a ground fault occurs on an inverter side or a traction motor connected to the inverter side according to a comparison result between a target voltage ratio of the traction auxiliary converter, which is determined to have the ground fault, and a first preset range after connection between the inverter side and the ground detection circuit is disconnected, wherein the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a ground voltage corresponding to the ground detection circuit and a dc link voltage of the rectifying side; if not, judging whether the ground fault occurs in the direct current link cathode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range, and judging whether the ground fault occurs in the direct current link anode of the rectifying side according to a comparison result between the target voltage ratio and a third preset range; if the ground fault is judged to be not generated at the negative pole or the positive pole of the direct current link of the rectifying side, whether the alternating current component exists in the ground voltage is further judged, if yes, the ground fault is positioned at the secondary side of the traction transformer between the traction transformer and the rectifying side, the ground fault of the traction auxiliary converter can be automatically and rapidly positioned, the positioning process is high in accuracy, the maintenance efficiency of fault equipment can be effectively improved, serious damage to the fault equipment in a short time is avoided, the operation safety and reliability of the traction auxiliary converter can be effectively improved, the normal operation of rail transit vehicles is effectively guaranteed, and the requirements of modern railways on intellectualization and safety are met.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of the structural relationship between a traction auxiliary converter and a traction transformer of a rail transit vehicle.

Fig. 2 is a schematic diagram of the structural relationship between a traction transformer and a pantograph of a rail transit vehicle.

Fig. 3 is a schematic diagram of a first configuration of the traction auxiliary converter.

Fig. 4 is an exemplary schematic diagram of the rectifying side in the traction auxiliary converter.

Fig. 5 is an exemplary schematic diagram of the inverter side in the traction auxiliary converter.

Fig. 6 is a schematic diagram of a ground fault point distribution based on a first configuration of the traction auxiliary current transformer.

Fig. 7 is a schematic diagram of a second configuration of the traction auxiliary converter.

Fig. 8 is a schematic diagram of a ground fault point distribution based on a second configuration of the traction auxiliary current transformer.

Fig. 9 is a schematic diagram of a first architecture of a ground fault point positioning system of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 10 is a schematic diagram of a second architecture of a ground fault point positioning system of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 11 is a flow chart of a method for positioning a ground fault point of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 12 is a flow chart of an automatic ground fault pre-judging process in the ground fault point positioning method of the rail transit traction auxiliary converter according to the embodiment of the application.

Fig. 13 is a schematic flow chart of an auxiliary converter ground fault judging process in the ground fault point positioning method of the rail transit traction auxiliary converter in the embodiment of the application.

Fig. 14 is a flowchart of step 100 in a method for positioning a ground fault point of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 15 is a flowchart of step 200 in a method for positioning a ground fault point of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 16 is a flowchart illustrating a procedure 300 in a method for positioning a ground fault point of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 17 is a flow chart of a method for positioning a ground fault point of a rail transit traction auxiliary converter in an application example of the present application.

Fig. 18 is a schematic diagram of a grounding loop of a dc link negative electrode in an application example of the present application.

Fig. 19 is a schematic diagram of a grounding loop of a dc link positive electrode in an application example of the present application.

Fig. 20 is a schematic waveform diagram of the grounding voltage U _g under the blocking state of the rectifying module in the case of the secondary side homonymous grounding of the traction transformer in the application example of the present application.

Fig. 21 is a schematic diagram of a grounding loop when 0< t < ₀ in the blocking state of the rectifier module in the case of the secondary side homonymous grounding of the traction transformer in the application example of the present application.

Fig. 22 is a schematic diagram of a ground circuit at t ₀<t<t₁ in the blocking state of the rectifier module in the case of the secondary side homonymous ground of the traction transformer in the application example of the present application.

Fig. 23 is a schematic diagram of a ground circuit at t ₁<t<t₂ in the blocking state of the rectifier module in the case of the secondary side homonymous ground of the traction transformer in the application example of the present application.

Fig. 24 is a schematic diagram of a ground circuit at t ₃<t<t₄ in the blocking state of the rectifier module in the case of the secondary side homonymous ground of the traction transformer in the application example of the present application.

Fig. 25 is a schematic diagram of a simulation waveform of U _g when R _g = 5kΩ in the blocking state of the rectifier module in the case of the secondary side homonymous ground of the traction transformer in the application example of the present application.

Fig. 26 is a schematic diagram of a dc link positive ground circuit when a G ₁ tube is turned on and the front end potential of a ground resistor R _g is U _c in the active state of a rectifier module in the case of the secondary side homonymous ground of a traction transformer in an application example of the present application.

Fig. 27 is a schematic diagram of a dc link negative ground circuit when a G ₂ tube is turned on and the front end potential of a ground resistor R _g is 0 in the active state of a rectifier module in the case of the secondary side homonymous ground of a traction transformer in an application example of the present application.

Fig. 28 is a schematic diagram of a simulation waveform of U _g when R _g = 5kΩ in the active state of the rectifier module in the case of the secondary side homonymous ground of the traction transformer in the application example of the present application.

Fig. 29 is a schematic structural diagram of a ground fault point positioning device of a rail transit traction auxiliary converter according to an embodiment of the present application.

Fig. 30 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Considering the situation that the traditional ground fault detection method of the traction auxiliary converter does not have the function of automatically positioning the ground fault point, and because the internal structure of the converter is complex and components are numerous, the manual troubleshooting of the fault point is complicated; the application provides a ground fault point positioning method of a rail traffic traction auxiliary converter, which is used for judging whether a ground fault occurs on a direct current link of a rectifying side or not according to a comparison result of a target voltage ratio of the traction auxiliary converter which is determined to occur the ground fault and a first preset range after connection between an inversion side and a ground detection circuit is disconnected, and judging whether the ground fault occurs on the inverting side or a traction motor connected to the inversion side according to a comparison result of the target voltage ratio of the traction auxiliary converter which is determined to occur the ground fault and a first preset range after connection between the inversion side and the ground detection circuit is disconnected, wherein the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a ground voltage corresponding to the ground detection circuit and a direct current link voltage of the rectifying side; if the ground fault is judged to be not generated at the negative pole or the positive pole of the direct current link of the rectifying side, whether the alternating current component exists in the ground voltage is further judged, and if the alternating current component exists in the ground voltage, the ground fault is positioned at the secondary side of the traction transformer between the traction transformer and the rectifying side. The ground fault of the traction auxiliary converter is automatically and quickly positioned by determining whether the ground fault point is on the inversion side or not, determining whether the ground fault point is on the direct current link or not, and finally determining whether the ground fault point is on the secondary side of the traction transformer or not, wherein the positioning process is high in accuracy, so that the maintenance efficiency of fault equipment can be effectively improved, serious damage to the fault equipment in a short time is avoided, the operation safety and reliability of the traction auxiliary converter can be effectively improved, the normal operation of rail transit vehicles is effectively ensured, and the requirements of modern railways on intellectualization and safety are met.

In one or more embodiments of the application, referring to fig. 1, a traction auxiliary converter 2 is provided between a traction transformer 1 and a traction motor 3 of a rail transit vehicle, which refers to a type of vehicle that travels on a particular track, such as an electric locomotive, a motor train unit, and the like. The traction transformer is an important component on the AC electric locomotive, and is used for converting the high-voltage obtained on the contact network into a voltage suitable for the operation of a traction motor, other motors and electric appliances, and the working principle of the traction transformer is the same as that of a common power transformer. The main transformer of the traction transformer is installed on an alternating current fed electric locomotive, and referring to fig. 2, the traction transformer 1 of the locomotive is arranged between a pantograph 4 and a ground return 6, and a main breaker 5 is arranged between the pantograph 4 and the traction transformer 1.

In one or more embodiments of the present application, referring to fig. 3, the rectifying side 21 of the traction auxiliary converter is connected to the secondary side of the traction transformer 1, and a switch Q is disposed between the rectifying side 21 and the traction transformer 1, the dc link of the rectifying side 21 is sequentially connected to a dc link capacitor C, and the dc link voltage is denoted by U _c, which can be measured by using a general voltage detection device; the inversion side 22 of the traction auxiliary converter is connected with the traction motor 3; the grounding detection circuit is composed of a voltage dividing resistor R ₁, a voltage dividing resistor R ₂ and a filter capacitor C _g, wherein the resistance value of the voltage dividing resistor R ₁ is exemplified by 99kΩ, and the resistance value of the voltage dividing resistor R ₂ is exemplified by 33kΩ. The grounding detection circuit is connected between the rectifying side 21 and the inverting side 22, and is close to the voltage dividing resistors R1 and R2 between the positive pole P of the direct current link and the negative pole N of the direct current link of the rectifying side 21, and the voltage dividing resistors R1 and R2 are connected in series, wherein the middle point of the voltage dividing resistors R1 and R2 is grounded, and the voltage at two sides of the resistor R2 is the grounding voltage U _g, and the grounding detection circuit can be obtained by measuring by using general voltage detection equipment.

In one example, the rectifying side 21 may include a rectifying module for converting ac power to dc power, and referring to fig. 4, the rectifying module may be composed of four IGBTs with anti-parallel diodes.

In one example, the inverter side 22 may include an inverter module for converting dc power to ac power, which may be comprised of six IGBTs with anti-parallel diodes, see fig. 5.

Based on the above, in one or more embodiments of the present application, the initial voltage ratio is a ratio U _g/U_c between the ground voltage U _g corresponding to the ground detection circuit and the dc link voltage U _c on the rectifying side. Correspondingly, the target voltage ratio is a value obtained by filtering the initial voltage ratio U _g/U_c, and is denoted by Y ₀.

Based on this, the principle of ground fault detection is: the ratio of the ground voltage U _g to the dc link voltage U _c is about 25% under normal conditions. If a ground fault occurs at a certain position of the traction auxiliary converter, a loop, namely a ground loop, is formed between the same name end of the secondary side of the traction transformer and the ground fault point and the ground-voltage dividing resistor R1/R2 and the non-same name end of the secondary side of the traction transformer, and the ground loop changes the ground voltage U _g, so that the initial voltage ratio U _g/U_c changes, and the ground fault at the certain position of the traction auxiliary converter can be judged according to the change.

In one or more embodiments of the application, the principle of ground fault point location is: upon or after determining that a ground fault has occurred, the range of values in which the target voltage ratio Y ₀ is located, and whether the ground voltage U _g has an ac component are further analyzed to locate a ground fault point.

In one or more embodiments of the present application, the located ground fault points are shown in table 1, and include: a. and the secondary side of the transformer is grounded, the positive electrode of the direct current link is grounded, the negative electrode of the direct current link is grounded, and the inversion module/traction motor is grounded. a. And the secondary side of the transformer is grounded, the positive electrode of the direct current link is grounded, the negative electrode of the direct current link is grounded, and the inversion module/traction motor is grounded. The distribution of the ground fault points is shown in fig. 6, for example.

TABLE 1

Identification mark	Ground fault point
		a	Transformer secondary side grounding
b	DC link positive electrode grounding
		c	DC link negative electrode grounding
d	Inverter module/traction motor grounding

In addition, on the basis of the foregoing description of the structure of the traction auxiliary converter, in one or more embodiments of the present application, the traction auxiliary converter may further include an auxiliary converter 23, and the internal structure of the auxiliary converter 23 may be the same as that of the inverter module. Referring to fig. 7, the auxiliary converter 23 is connected to the traction auxiliary converter through an input contactor K.

Based on this, the located ground fault point may be as shown in table 2, including: a. and the secondary side of the transformer is grounded, the positive electrode of the direct current link is grounded, the negative electrode of the direct current link is grounded, and the inversion module/traction motor is grounded. a. The secondary side of the transformer is grounded, the positive electrode of the direct current link is grounded, the negative electrode of the direct current link is grounded, the inverter module/traction motor is grounded, and the auxiliary converter is grounded at a certain point. The distribution of the ground fault points is shown in fig. 8, for example.

TABLE 2

That is, the method for positioning the ground fault point of the rail transit traction auxiliary converter of the present application can be applied to the traction auxiliary converter without changing the self structure of the traction auxiliary converter, regardless of whether the traction auxiliary converter includes an auxiliary converter or whether the traction auxiliary converter includes more than one auxiliary converter.

Based on the above, the present application further provides a ground fault point positioning system of a rail transit traction auxiliary current transformer including a ground fault point positioning device of the rail transit traction auxiliary current transformer, in which the ground fault point positioning device of the rail transit traction auxiliary current transformer may be a server A1, see fig. 9, the server A1 may be in communication connection with at least one controller B1 for controlling the traction auxiliary current transformer and at least one voltage detection device C1 for detecting a direct current link voltage U _c and a detected ground voltage U _g of the traction auxiliary current transformer, the voltage detection device C1 may periodically or in real time transmit the direct current link voltage U _c and the detected ground voltage U _g of the traction auxiliary current transformer to the server A1, so that after the server A1 determines that the current traction auxiliary current transformer has a ground fault according to a target voltage ratio Y ₀, a ground fault point positioning start command may be transmitted to the controller B1, and the controller may start the controller according to the ground fault point positioning command to start the traction auxiliary current transformer, for example, if the traction auxiliary current transformer is not connected to the inverter side of the traction auxiliary current transformer is blocked; if the traction auxiliary converter includes an auxiliary converter, the controller B1 firstly disconnects the input contactor K, i.e. disconnects the auxiliary converter from the traction auxiliary converter. Then, no matter the controller B1 controls the inversion side to be disconnected or controls the auxiliary converter to be disconnected, notification information is sent to the server A1, so that the server A1 executes a specific process of the ground fault point positioning method of the rail transit traction auxiliary converter, and finally the ground fault point of the traction auxiliary converter is obtained.

On this basis, in order to further improve the automation and the intelligent degree of the ground fault point positioning process of the whole rail transit traction auxiliary converter, the ground fault point positioning device of the rail transit traction auxiliary converter can also be used with at least one database D1 and at least one client device E1, see fig. 10, after the ground fault point of the traction auxiliary converter is obtained, the server A1 can store the data into the corresponding database D1 so as to be used in a subsequent trace, meanwhile, after the ground fault point of the traction auxiliary converter is obtained, the server A1 can also be used for sending the ground fault point of the traction auxiliary converter into at least one client device E1, so that a dispatching manager and a technical maintenance staff can both know the ground fault point at the first time through the corresponding client device E1, and further can directly reach the ground fault point and carry out emergency treatment and maintenance, so that serious damage to the fault device in a short time can be avoided, the running safety and reliability of the traction auxiliary converter can be effectively improved, and the normal running of the rail transit can be effectively ensured.

It is understood that the client device may include a smart phone, a tablet electronic device, a network set top box, a portable computer, a desktop computer, a Personal Digital Assistant (PDA), an in-vehicle device, a smart wearable device, etc. Wherein, intelligent wearing equipment can include intelligent glasses, intelligent wrist-watch, intelligent bracelet etc..

The client device may have a communication module (i.e. a communication unit) and may be connected to a remote server in a communication manner, so as to implement data transmission with the server. The communication unit may also receive a ground fault point location result returned by the server. The server may include a server on the side of the task scheduling center, and in other implementations may include a server of an intermediate platform, such as a server of a third party server platform having a communication link with the task scheduling center server. The server may include a single computer device, a server cluster formed by a plurality of servers, or a server structure of a distributed device.

Any suitable network protocol may be used for communication between the server and the client device, including those not yet developed on the filing date of the present application. The network protocols may include, for example, TCP/IP protocol, UDP/IP protocol, HTTP protocol, HTTPS protocol, etc. Of course, the network protocol may also include, for example, RPC protocol (Remote Procedure Call Protocol ), REST protocol (Representational STATE TRANSFER) or the like used above the above-described protocol.

Based on the above, the ground fault point positioning technology of the rail transit traction auxiliary converter can automatically and rapidly position the ground fault of the traction auxiliary converter, the positioning process is high in accuracy, the maintenance efficiency of fault equipment can be effectively improved, serious damage of the fault equipment in a short time is avoided, the operation safety and reliability of the traction auxiliary converter can be effectively improved, the normal operation of rail transit vehicles is effectively ensured, and the requirements of modern railways on intellectualization and safety are met. The following embodiments and application examples are specifically described.

In order to automatically and quickly locate a ground fault of a traction auxiliary converter, an embodiment of the present application provides an execution process of a ground fault point locating method of a rail transit traction auxiliary converter, referring to fig. 11, the ground fault point locating method of the rail transit traction auxiliary converter specifically includes the following contents:

Step 100: after the connection between the inverter side and the ground detection circuit is disconnected, it is determined whether the ground fault occurs in the inverter side or a traction motor connected to the inverter side, based on a result of comparing a target voltage ratio of the traction auxiliary converter, which has been determined that the ground fault has occurred, with a first preset range.

The target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a grounding voltage corresponding to the grounding detection circuit and the direct current link voltage of the rectifying side.

If not, go to step 200.

In step 100, if it has been determined that the current traction auxiliary converter has a ground fault and the connection between the inverter side and the ground detection circuit in the traction auxiliary converter has been disconnected, it is determined whether the ground fault point is the disconnected inverter side or the traction motor connected to the inverter side by testing whether the target voltage ratio is restored to be normal, if the target voltage ratio is restored to be normal, it is indicated that the ground fault point is the traction motor located on the inverter side or connected to the inverter side, and the maintenance personnel can directly perform fault detection for the location. If the target voltage ratio is not still recovered, it is indicated that the ground fault point is not the inverter side or the traction motor connected to the inverter side, and thus it is necessary to find the ground fault point by performing step 200.

It can be understood that the first preset range may be a% -B%, where a% -B% is determined by considering factors such as voltage fluctuation and false alarm reduction on the basis that the theoretical value of Y ₀ is 25%, that is, a% = 25% -x%, B% = 25% + x%, and x% is obtained in advance by an actual test. In one example, x% may be 6% or 8%.

Step 200: judging whether the ground fault occurs at the direct current link cathode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range, and judging whether the ground fault occurs at the direct current link anode of the rectifying side according to a comparison result between the target voltage ratio and a third preset range.

If not, go to step 300.

In step 200, it has been determined that the ground fault point of the current traction auxiliary converter is not the inverter side or the traction motor connected to the inverter side, so it is further determined whether the ground fault point is the dc link negative or positive electrode on the rectifying side, if not, it is indicated that the ground fault point is not the dc link negative or positive electrode, and it is also necessary to find the ground fault point by executing step 300.

It is understood that the second preset range is determined according to a% of the second preset range, specifically, the second preset range is 0 to a%.

The third preset range is C-100%, and C% is determined by theoretical calculation value and actual test value of the initial voltage ratio U _g/U_c. In one example, C% may be 60% or 80%.

Step 300: if the ground fault is judged to be not generated at the negative pole or the positive pole of the direct current link of the rectifying side, whether the alternating current component exists in the ground voltage is further judged, and if the alternating current component exists in the ground voltage, the ground fault is positioned at the secondary side of the traction transformer between the traction transformer and the rectifying side.

From the above description, the ground fault point positioning method of the rail transit traction auxiliary converter provided by the embodiment of the application can automatically and rapidly position the ground fault of the traction auxiliary converter, has high accuracy in the positioning process, further can effectively improve the maintenance efficiency of fault equipment, avoid serious damage to the fault equipment in a short time, further can effectively improve the operation safety and reliability of the traction auxiliary converter, effectively ensure the normal operation of rail transit vehicles, and meet the requirements of modern railways on intellectualization and safety.

In order to automatically pre-determine that the ground fault occurs in the traction auxiliary converter, so as to further improve the accuracy and the automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in an embodiment of the present application, referring to fig. 12, before step 100 of the ground fault point positioning method of the rail transit traction auxiliary converter further includes the following contents:

step 011: acquiring the initial voltage ratio of the current traction auxiliary converter;

step 012: performing low-pass filtering on the initial voltage ratio to obtain a target voltage ratio of the current traction auxiliary converter;

Step 013: judging whether the target voltage ratio of the current traction auxiliary converter is within the first preset range, if not, executing step 014, and if so, returning to step 011.

Step 014: and determining that the current traction auxiliary converter has a ground fault, and entering a ground fault point positioning process.

In an embodiment of the present application, if the auxiliary converter includes the auxiliary converter, after entering the ground fault point positioning process in step 014 and before determining whether the inverter side or the traction motor sends the ground fault in step 100, it is further required to determine whether the node fault point is the auxiliary converter, so as to effectively improve the applicability of the present application. That is, between step 014 and step 100, referring to fig. 13, the method for positioning a ground fault point of the rail transit traction auxiliary converter further includes the following steps:

Step 021: disconnecting the auxiliary current transformer from the traction auxiliary current transformer;

step 022: judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the first preset range;

if not, it is determined that the ground fault is not a traction auxiliary converter, and the process continues to step 023.

If so, it is indicated that the ground fault point is the traction auxiliary converter, so step 024 is performed.

Step 023: and disconnecting the connection between the inversion side and the grounding detection circuit.

Step 100 is performed after step 023.

Step 024: positioning the ground fault at the auxiliary converter. And then ending the positioning process of the grounding fault point.

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in an embodiment of the present application, referring to fig. 14, step 100 in the ground fault point positioning method of the rail transit traction auxiliary converter specifically includes the following:

Step 101: judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the first preset range;

if yes, the step 102 is executed if the ground fault point is the inversion side or the traction motor connected to the inversion side; if not, go to step 200.

Step 102; the ground fault is located at the inverter side or a traction motor connected to the inverter side. And then ending the positioning process of the grounding fault point.

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in an embodiment of the present application, referring to fig. 15, step 200 in the ground fault point positioning method of the rail transit traction auxiliary converter specifically includes the following:

step 201: judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the second preset range;

if yes, the ground fault point is the negative pole of the direct current link, and step 202 is executed; if not, go to step 203.

Step 202: and positioning the ground fault at the direct current link cathode of the rectifying side. And then ending the positioning process of the grounding fault point.

Step 203: continuously judging whether the target voltage ratio of the traction auxiliary converter with the determined ground fault is within the third preset range;

If yes, the ground fault point is the positive pole of the direct current link; step 204 is performed; if not, go to step 300.

Step 204: and positioning the ground fault at the positive pole of the direct current link of the rectifying side. And then ending the positioning process of the grounding fault point.

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in one embodiment of the present application, referring to fig. 16, step 300 in the ground fault point positioning method of the rail transit traction auxiliary converter specifically includes the following:

Step 301: judging whether the grounding voltage has an alternating current component or not, if so, indicating that the grounding fault point is the secondary side of the traction transformer, and executing step 302; if not, go to step 303.

Step 302: positioning the ground fault on a secondary side of the traction transformer between the traction transformer and a rectifying side. And then ending the positioning process of the grounding fault point.

Step 303: and positioning the ground fault at the positive pole of the direct current link of the rectifying side. And then ending the positioning process of the grounding fault point.

In order to further explain the scheme, the application also provides a specific application example of the ground fault point positioning method of the rail transit traction auxiliary converter, referring to fig. 17, the ground fault point positioning method of the rail transit traction auxiliary converter specifically comprises the following contents:

S1, calculating a ratio U _g/U_c, filtering to obtain Y ₀, and judging whether Y ₀ exceeds the range of A-B% or not and lasts for 500ms. If yes, judging that the ground fault occurs, and entering a ground fault point positioning flow; if not, the process is jumped out.

In step S1, after calculating the ratio U _g/U_c, the low-pass filtering with a cut-off frequency of 5Hz is needed to obtain Y ₀ so as to remove the voltage detection interference. The A-B% is the normal range of Y ₀, which is obtained by taking voltage fluctuation into account by 25% of the theoretical value of Y ₀, reducing false alarm and subtracting and adding x%, and x% is obtained by actual test.

S2, disconnecting the input contactor K of the auxiliary converter, and continuously judging whether Y ₀ exceeds the range of A-B%. If yes, continuing the positioning process; if not, judging that the auxiliary converter is grounded and jumps out of the flow.

Step S2, determining whether a ground fault occurs in the auxiliary converter: the input contactor of the auxiliary converter is disconnected, namely, a grounding loop of the grounding fault of the auxiliary converter is cut off, and at the moment, if Y ₀ is recovered to be between A and B percent, the auxiliary converter is confirmed to be grounded. Otherwise, continuing the positioning process.

S3, blocking the inversion module, namely turning off all IGBTs of the inversion module, and continuously judging whether Y ₀ exceeds the range of A-B%. If yes, continuing the positioning process; if not, judging that the inversion module or the traction motor is grounded and jumps out of the process. Step S3, determining whether a ground fault occurs in the inverter module or the traction motor: the principle is the same as that of the step S2.

S4, continuously judging whether Y ₀ is between 0 and A percent. If yes, judging that the negative electrode of the direct current link is grounded and jumps out of the flow; if not, continuing the positioning process. And S4, judging whether the negative electrode of the direct current link is grounded. The ground loop of the negative pole of the dc link is shown in fig. 18, and the theoretical value of U _g/U_c is obtained as follows:

U_g/U_c＝R_g*R₂/(R_g*R₂+R₁*R₂+R₁*R_g)

The ground fault has various forms, such as short circuit of conductor, water inlet, burnout of insulating layer, etc., and the corresponding ground resistors are different. The theoretical values of U _g/U_c when the ground resistance R _g =0, 5kΩ,20kΩ, and 100deg.kΩ are shown in table 3. Considering voltage fluctuation, when Y ₀ is between 0 and A%, the negative electrode of the direct current link is judged to be grounded.

TABLE 3 Table 3

R_g	0	5kΩ	20kΩ	100kΩ
					(U_g/U_c)*100％	0	4％	11％	20％

S5, continuously judging whether Y ₀ is between C and 100 percent. If yes, judging the grounding of the positive electrode of the direct current link and jumping out of the process; if not, continuing the positioning process. And S5, judging whether the positive electrode of the direct current link is grounded. The theoretical value of U _g/U_c obtained by the dc link positive ground loop is shown in fig. 19 is as follows:

U_g/U_c＝R₂/(R₁*R_g/(R₁+R_g)+R₂)

The theoretical values of U _g/U_c when the ground resistance R _g =0, 5kΩ,20kΩ, and 100deg.kΩ are shown in table 4. When Y ₀ is between C and 100 percent, judging that the positive electrode of the direct current link is grounded; otherwise, the positioning procedure needs to be continued. C% is a value obtained by integrating the theoretical calculation value and the actual test of Table 4.

TABLE 4 Table 4

R_g	0	5kΩ	20kΩ	100kΩ
					(U_g/U_c)*100％	100％	87.4％	66.5％	40％

S6, continuing to judge whether the U _g has an alternating current component. If yes, judging that the secondary side of the traction transformer is grounded and jumps out of the process; if not, judging that the positive electrode of the direct current link is grounded and jumps out of the flow.

In step S6, Y ₀ is between B% and C%, and it is further calculated whether the ground voltage U _g has an ac component: if the alternating current component exists, judging that the secondary side of the traction transformer is grounded; otherwise, the positive electrode of the direct current link is judged to be grounded.

It will be appreciated that in the case of traction transformer secondary grounding, U _g has an ac component, the principle of which is analyzed as follows:

1. traction transformer secondary side homonymous grounding condition

(1) Rectifier module lockout condition

The rectification module is in a blocking state, namely, the rectification module operates in an uncontrolled rectification mode, only the anti-parallel diode of the IGBT works, the effective value U ₂ =1900V of the secondary side voltage U ₂ of the traction transformer, the direct-current link voltage U _c =2686V, and the waveform of the grounding voltage U _g is shown in fig. 20 by taking R _g =0 as an example in one power frequency period.

a.0<t<t₀

The ground loop is shown in fig. 21. During this period, u ₂ increases from 0, and u ₂<U_g. The voltage across diode D ₄ is:

U_D4＝u₂-U_g

So D ₄ is back-voltage-cut-off, and the dc link capacitor C charges the grounded filter capacitor C _g.

b.t₀<t<t₁

During this period U ₂>U_g, diode D ₄ is turned on and the ground loop is forced to U ₂ as shown in fig. 22, U _g.

c.t₁<t<t₂

At this point 0<u ₂<U_g, diode D ₄ turns off and the ground equivalent loop discharges, C _g, as shown in fig. 23.

d.t₂<t<t₃

At this point, the negative half cycle of u ₂ begins, during which time the voltage across diode D ₃ is 0< -u ₂<U_R1:

U_D3＝-u₂–U_R21

Thus, D ₃ is turned off and the ground loop discharges as in case D, C _g.

e.t₃<t<t₄

At this time D ₃ is on, the ground loop is forced to U ₂ by U _R1 as shown in fig. 24, so U _g is forced to U _c+u₂.

f.t₄<t<t₅

At this time, D ₃ is turned off and the ground loop is charged as in case a, C _g.

Corresponding to the case where the ground resistance R _g is not 0, the ground loop is the same as the above case, the U _g waveform is similar to the above case, and the U _g simulation waveform when R _g =5kΩ is shown in fig. 25.

(2) Rectifier module active state

The rectification module is activated, i.e. works in a controllable rectification state, U ₂＝1900V,U_c =3600v, and as an example, R _g =0, there are two cases of the ground loop:

a. When the G ₁ pipe is turned on, the front end potential of the grounding resistor R _g is U _c, and as shown in FIG. 26, the situation is equivalent to the grounding of the positive electrode in the DC link.

B. When the G ₂ pipe is opened, the front end potential of the grounding resistor R _g is 0, as shown in fig. 27, and the situation is equivalent to the grounding of the negative electrode of the direct current link.

Therefore, in the active state of the rectifying module, U _g is related to the switching state of the G ₁、G₂ tube only, and when R _g =0, U _g is a pulse voltage. When R _g is not 0, the pulse voltage continuously charges and discharges the filter capacitor C _g to form a waveform similar to a sawtooth sine, but is positive. The U _g simulation waveform is shown in fig. 28 when R _g =5kΩ.

2. Traction transformer secondary side non-homonymous grounding condition

Under the condition that the secondary side of the traction transformer is grounded in the same name, whether the rectification module is activated or not, the waveform of the grounding voltage U _g is 180 degrees different from the waveform of the grounding voltage in the same name.

In the case of the secondary side grounding of the traction transformer, the value Y ₀ of U _g/U_c after low-pass filtering at the cut-off frequency of 5Hz is shown in table 5 when the grounding resistance R _g =0, 5kΩ,20kΩ,100kΩ.

TABLE 5

R_g	0	5kΩ	20kΩ	100kΩ
					Y₀	45.6％	42.3％	36.4％	29.3％

In summary, in step S6, Y ₀ is between B% and C%, and if the grounding voltage U _g has an ac component, it is determined that the secondary side of the traction transformer is grounded; otherwise, the positive electrode of the direct current link is judged to be grounded.

From the above description, the method for positioning the ground fault point of the rail transit traction auxiliary converter provided by the application example of the application needs to change the existing ground detection hardware circuit, thereby saving the cost. The ground fault point can be rapidly positioned while the ground fault is accurately judged, a complex manual checking process is omitted, the fault processing efficiency is improved, meanwhile, the loss of equipment caused by the ground fault is avoided, and the safety of the system is improved.

In order to automatically and quickly locate the ground fault of the traction auxiliary converter from a software aspect, the application provides an embodiment of a ground fault point locating device of a rail transit traction auxiliary converter capable of implementing the whole content in the ground fault point locating method of the rail transit traction auxiliary converter, referring to fig. 29, the ground fault point locating device of the rail transit traction auxiliary converter specifically comprises the following contents:

And an inverter ground fault judging module 10, configured to judge whether the ground fault occurs on the inverter side or a traction motor connected to the inverter side according to a comparison result of a target voltage ratio of the traction auxiliary converter determined to have the ground fault with a first preset range after the connection between the inverter side and the ground detection circuit is disconnected, where the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a ground voltage corresponding to the ground detection circuit and a dc link voltage of the rectifying side.

And the dc link ground fault judging module 20 is configured to judge whether the ground fault occurs at the dc link negative electrode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range, and judge whether the ground fault occurs at the dc link positive electrode of the rectifying side according to a comparison result between the target voltage ratio and a third preset range, if the ground fault does not occur at the inverting side.

The transformer secondary side ground fault judging module 30 is configured to further judge whether the ground voltage has an ac component if it is judged that the ground fault does not occur in the dc link negative electrode or the dc link positive electrode of the rectifying side, and if so, locate the ground fault on the secondary side of the traction transformer between the traction transformer and the rectifying side.

The embodiment of the ground fault point positioning device of the rail transit traction auxiliary converter provided by the application can be particularly used for executing all the processing flows of each embodiment of the ground fault point positioning method of the rail transit traction auxiliary converter in the embodiment, and the functions of the embodiment are not repeated herein, and can be described in detail with reference to the embodiment of the method.

From the above description, the ground fault point positioning device of the rail transit traction auxiliary converter provided by the embodiment of the application can automatically and rapidly position the ground fault of the traction auxiliary converter, has high accuracy in the positioning process, further can effectively improve the maintenance efficiency of fault equipment, avoid serious damage to the fault equipment in a short time, further can effectively improve the operation safety and reliability of the traction auxiliary converter, effectively ensure the normal operation of rail transit vehicles, and meet the requirements of modern railways on intellectualization and safety.

In order to automatically pre-judge the ground fault of the traction auxiliary converter so as to further improve the accuracy and the automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in one embodiment of the present application, the ground fault point positioning device of the rail transit traction auxiliary converter further includes a ground fault detection module 01, where the ground fault detection module 01 is specifically configured to execute the following:

In an embodiment of the present application, if the auxiliary traction converter includes the auxiliary converter, after entering the positioning process of the ground fault point and before determining whether the inverter side or the traction motor sends the ground fault, it is further required to determine whether the node fault point is the auxiliary converter, so as to effectively improve the application scope of the present application. That is, the ground fault point positioning device of the rail transit traction auxiliary converter further comprises an auxiliary converter ground fault judging module 02, wherein the auxiliary converter ground fault judging module 02 is specifically configured to execute the following:

Step 100 is performed after step 023.

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in one embodiment of the present application, the inverter ground fault determining module 10 in the ground fault point positioning device of the rail transit traction auxiliary converter is specifically configured to execute the following:

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in one embodiment of the present application, the dc link ground fault determining module 20 in the ground fault point positioning device of the rail transit traction auxiliary converter is specifically configured to execute the following:

In order to further improve the accuracy and automation degree of the ground fault point positioning process of the rail transit traction auxiliary converter, in one embodiment of the present application, the secondary side ground fault determining module 30 of the transformer in the ground fault point positioning device of the rail transit traction auxiliary converter is specifically configured to perform the following:

From the hardware aspect, the embodiment of the present application further provides a specific implementation manner of an electronic device capable of implementing all the steps in the ground fault point positioning method of the rail transit traction auxiliary converter in the foregoing embodiment, and referring to fig. 30, the electronic device specifically includes the following contents:

A processor 601, a memory 602, a communication interface (Communications Interface) 603, and a bus 604;

wherein the processor 601, the memory 602, and the communication interface 603 complete communication with each other through the bus 604; the communication interface 603 is configured to enable information transmission among the server S1, the controller B1, the voltage detection device C1, the database D1, the client device E1, and other participating mechanisms;

The processor 601 is configured to invoke a computer program in the memory 602, where the processor executes the computer program to implement all the steps in the ground fault point positioning method of the rail transit traction auxiliary converter in the foregoing embodiment, for example, the processor executes the computer program to implement the following steps:

Step 100: after the connection between the inversion side and the ground detection circuit is disconnected, judging whether the ground fault occurs on the inversion side or a traction motor connected to the inversion side according to a comparison result of a target voltage ratio of the traction auxiliary converter, which is determined to have the ground fault, and a first preset range, wherein the target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a ground voltage corresponding to the ground detection circuit and a direct current link voltage of the rectification side.

If not, go to step 200.

If not, go to step 300.

From the above description, it can be known that the electronic device provided by the embodiment of the application can automatically and quickly locate the ground fault of the traction auxiliary converter, and the accuracy of the locating process is high, so that the maintenance efficiency of the fault device can be effectively improved, serious damage to the fault device in a short time can be avoided, the operation safety and reliability of the traction auxiliary converter can be effectively improved, the normal operation of rail transit vehicles can be effectively ensured, and the requirements of modern railways on intellectualization and safety can be met.

From the storage medium level, the embodiment of the present application further provides a computer readable storage medium capable of implementing all the steps in the ground fault point positioning method of the rail transit traction auxiliary converter in the above embodiment, where the computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the computer program implements all the steps in the ground fault point positioning method of the rail transit traction auxiliary converter in the above embodiment, for example, the processor implements the following steps when executing the computer program:

If not, go to step 200.

If not, go to step 300.

As can be seen from the above description, the computer readable storage medium provided by the embodiment of the application can automatically and quickly locate the ground fault of the traction auxiliary converter, has high accuracy in the locating process, further can effectively improve the maintenance efficiency of fault equipment, avoid serious damage to the fault equipment in a short time, further can effectively improve the operation safety and reliability of the traction auxiliary converter, effectively ensure the normal operation of rail transit vehicles, and meet the requirements of modern railways on intellectualization and safety.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a hardware+program class embodiment, the description is relatively simple, as it is substantially similar to the method embodiment, as relevant see the partial description of the method embodiment.

The foregoing describes specific embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Although the application provides method operational steps as described in the examples or flowcharts, more or fewer operational steps may be included based on conventional or non-inventive labor. The order of steps recited in the embodiments is merely one way of performing the order of steps and does not represent a unique order of execution. When implemented by an actual device or client product, the instructions may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment) as shown in the embodiments or figures.

The system, apparatus, module or unit set forth in the above embodiments may be implemented in particular by a computer chip or entity, or by a product having a certain function. One typical implementation is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a car-mounted human-computer interaction device, a cellular telephone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

Although the present description provides method operational steps as described in the examples or flowcharts, more or fewer operational steps may be included based on conventional or non-inventive means. The order of steps recited in the embodiments is merely one way of performing the order of steps and does not represent a unique order of execution. When implemented in an actual device or end product, the instructions may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even in a distributed data processing environment) as illustrated by the embodiments or by the figures. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, it is not excluded that additional identical or equivalent elements may be present in a process, method, article, or apparatus that comprises a described element.

For convenience of description, the above devices are described as being functionally divided into various modules, respectively. Of course, when implementing the embodiments of the present disclosure, the functions of each module may be implemented in the same or multiple pieces of software and/or hardware, or a module that implements the same function may be implemented by multiple sub-modules or a combination of sub-units, or the like. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

Those skilled in the art will also appreciate that, in addition to implementing the controller in a pure computer readable program code, it is well possible to implement the same functionality by logically programming the method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Such a controller can be regarded as a hardware component, and means for implementing various functions included therein can also be regarded as a structure within the hardware component. Or even means for achieving the various functions may be regarded as either software modules implementing the methods or structures within hardware components.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It will be appreciated by those skilled in the art that embodiments of the present description may be provided as a method, system, or computer program product. Accordingly, the present specification embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present description embodiments may take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present embodiments may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The embodiments of the specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, as relevant to see a section of the description of method embodiments. In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present specification. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

The foregoing is merely an example of an embodiment of the present disclosure and is not intended to limit the embodiment of the present disclosure. Various modifications and variations of the illustrative embodiments will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, or the like, which is within the spirit and principles of the embodiments of the present specification, should be included in the scope of the claims of the embodiments of the present specification.

Claims

1. The utility model provides a ground fault point positioning method of rail transit traction auxiliary converter, its characterized in that is equipped with ground detection circuit between traction auxiliary converter's rectification side and the contravariant side, and the rectification side is connected with rail transit vehicle's traction transformer, the method includes:

Acquiring an initial voltage ratio of a current traction auxiliary converter;

judging whether the target voltage ratio of the current traction auxiliary converter is within a first preset range or not so as to determine whether the current traction auxiliary converter has no ground fault or not; if not, determining that the current traction auxiliary converter has a ground fault; the traction auxiliary converter is also connected with an auxiliary converter;

Disconnecting the auxiliary current transformer from the traction auxiliary current transformer; and determining whether a target voltage ratio of the traction auxiliary converter for which the ground fault has been determined to occur is within the first preset range, to determine whether the ground fault occurs in the auxiliary converter;

If not, disconnecting the connection between the inversion side and the grounding detection circuit; judging whether the ground fault occurs on the inversion side or a traction motor connected to the inversion side according to a comparison result of a target voltage ratio of the traction auxiliary converter with the determined ground fault and a first preset range;

The target voltage ratio is a value obtained by filtering an initial voltage ratio, and the initial voltage ratio is a ratio between a grounding voltage corresponding to the grounding detection circuit and the direct current link voltage of the rectifying side; the traction transformer is arranged between the pantograph and the ground reflux, a main breaker is arranged between the pantograph and the traction transformer, the rectifying side of the traction auxiliary converter is connected with the secondary side of the traction transformer, a switch is arranged between the rectifying side and the traction transformer, a direct-current link of the rectifying side is connected with a direct-current link capacitor, and the direct-current link voltage is measured by using voltage detection equipment; the inversion side of the traction auxiliary converter is connected with a traction motor; the grounding detection circuit consists of a voltage dividing resistor R1, a voltage dividing resistor R2 and a filter capacitor, wherein the voltage dividing resistor R1 and the voltage dividing resistor R2 are connected in series, the middle point of the voltage dividing resistor R1 and the middle point of the voltage dividing resistor R2 are grounded, the voltage at the two sides of the voltage dividing resistor R2 is the grounding voltage, and the grounding voltage is obtained by measuring by using voltage detection equipment; the rectifying side comprises a rectifying module for converting alternating current into direct current, and the rectifying module consists of four insulated gate bipolar transistors IGBT with anti-parallel diodes; the inversion side comprises an inversion module for converting direct current into alternating current, and the inversion module consists of six insulated gate bipolar transistors IGBT with anti-parallel diodes;

If the ground fault does not occur on the inversion side or the traction motor connected to the inversion side, judging whether the ground fault occurs on the direct current link negative electrode of the rectification side according to a comparison result between the target voltage ratio and a second preset range;

If the ground fault is judged and known not to occur at the direct current link negative electrode of the rectifying side, further judging whether the ground voltage has an alternating current component or not;

If the alternating current component exists in the ground voltage through further judgment, positioning the ground fault on the secondary side of the traction transformer between the traction transformer and the rectifying side;

2. The ground fault point locating method of claim 1, further comprising:

after the auxiliary converter and the traction auxiliary converter are disconnected, if the target voltage ratio of the traction auxiliary converter determined to have the ground fault is within the first preset range after the judgment, the ground fault is positioned at the auxiliary converter.

3. The ground fault point positioning method according to claim 1, wherein the determining whether the ground fault occurs at the inverter side or a traction motor connected to the inverter side based on a comparison result of a target voltage ratio of the traction auxiliary converter, which has been determined to have the ground fault, with a first preset range, includes:

4. The method according to claim 1, wherein the determining whether the ground fault occurs at the dc link negative electrode on the rectifying side according to the comparison result between the target voltage ratio and a second preset range includes:

5. The method according to claim 4, wherein the determining whether the ground fault occurs at the dc link positive electrode on the rectifying side according to the comparison result between the target voltage ratio and a third preset range includes:

6. The utility model provides a ground fault point positioner of rail transit traction auxiliary converter, its characterized in that is equipped with ground detection circuit between traction auxiliary converter's rectification side and the contravariant side, just the rectification side is connected with rail transit vehicle's traction transformer, ground fault point positioner includes:

The ground fault detection module is used for obtaining the initial voltage ratio of the current traction auxiliary converter; performing low-pass filtering on the initial voltage ratio to obtain a target voltage ratio of the current traction auxiliary converter; judging whether the target voltage ratio of the current traction auxiliary converter is in a first preset range or not so as to determine whether the current traction auxiliary converter has no ground fault or not; if not, determining that the current traction auxiliary converter has a ground fault; the traction auxiliary converter is also connected with an auxiliary converter;

The auxiliary converter ground fault judging module is used for disconnecting the auxiliary converter from the traction auxiliary converter after determining that the current traction auxiliary converter has a ground fault; and determining whether a target voltage ratio of the traction auxiliary converter for which the ground fault has been determined to occur is within the first preset range, to determine whether the ground fault occurs in the auxiliary converter;

An inverter ground fault judging module for disconnecting the connection between the inverter side and the ground detection circuit after determining that the ground fault does not occur in the auxiliary converter; after the connection between the inversion side and the grounding detection circuit is disconnected, judging whether the grounding fault occurs on the inversion side or a traction motor connected to the inversion side according to a comparison result of a target voltage ratio of the traction auxiliary converter, which is determined to have the grounding fault, and a first preset range;

The direct current link grounding fault judging module is used for judging whether the grounding fault occurs at the direct current link negative electrode of the rectifying side according to a comparison result between the target voltage ratio and a second preset range if the grounding fault does not occur at the inverting side or the traction motor connected to the inverting side;

The secondary side grounding fault judging module of the transformer is used for further judging whether the grounding voltage has an alternating current component or not if the judgment shows that the grounding fault does not occur at the negative pole of the direct current link of the rectifying side, and if so, positioning the grounding fault at the secondary side of the traction transformer between the traction transformer and the rectifying side; and if the ground voltage is further judged to have no alternating current component, positioning the ground fault at the positive pole of the direct current link at the rectifying side.

7. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the ground fault point positioning method of the rail transit traction auxiliary converter of any one of claims 1 to 5 when the program is executed by the processor.