CN104749475A - Motor vehicle island detection method and system - Google Patents
Motor vehicle island detection method and system Download PDFInfo
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- CN104749475A CN104749475A CN201510202374.6A CN201510202374A CN104749475A CN 104749475 A CN104749475 A CN 104749475A CN 201510202374 A CN201510202374 A CN 201510202374A CN 104749475 A CN104749475 A CN 104749475A
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Abstract
The invention provides a motor vehicle island detection method. The method comprises the following steps: under the situation that a network detection current transformer runs normally, acquiring the primary side voltage and full intermediate direct-current voltage of a main transformer; acquiring the current switch-on/off state of each phase of the network detection current transformer; computing the virtual network voltage with a preset formula according to the full intermediate direct-current voltage and the switch-on/off state of each phase; comparing the virtual network voltage with the primary side voltage of the main transformer, and judging that an island fault occurs when the difference value between the virtual network voltage and the primary side voltage of the main transformer satisfies a preset condition. The island detection method based on the virtual network voltage is adopted, so that detection of a motor vehicle island can be performed effectively.
Description
Technical field
The application relates to islanding detect field, particularly a kind of locomotive island detection method and system.
Background technology
Along with the development of technology, the requirement of people to locomotive islanding detect is more and more higher.
Existing locomotive island detection method general algorithm is complicated, and detection time is long, is difficult to Project Realization, and its accuracy detected is difficult to engineering verification.
Therefore, the detection how effectively carrying out locomotive isolated island is the current technical issues that need to address of those skilled in the art.
Summary of the invention
Technical problems to be solved in this application are to provide a kind of locomotive island detection method and system, effectively can carry out the detection of locomotive isolated island.
Its concrete scheme is as follows:
A kind of locomotive island detection method, the method comprises:
When netting survey current transformer and normally running, gather main-transformer original edge voltage and full middle dc voltage;
Obtain the on off state that the current each phase of current transformer surveyed by described net;
According to the on off state of described full middle dc voltage and described current each phase, according to preset formula, calculate virtual net pressure;
Described virtual net pressure is compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
Above-mentioned method, preferably, the described on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure, comprising:
According to the on off state of described full middle dc voltage and described current each phase, calculate the voltage that current transformer ac input end surveyed by described net;
According to described no-load voltage ratio of netting voltage, leakage inductance and the transformer surveying current transformer ac input end, according to preset formula, calculate virtual net pressure.
Above-mentioned method, preferably, described pressure by described virtual net compares with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges locomotive generation isolated island fault, comprising:
The threshold value that setting isolated island judges;
When described virtual net pressure and the difference of described main-transformer original edge voltage are more than or equal to the threshold value that described isolated island judges, then judge locomotive generation isolated island fault.
A kind of locomotive alone island detection system, this system comprises:
Collecting unit, for when netting survey current transformer and normally running, gathers main-transformer original edge voltage and full middle dc voltage;
Acquiring unit, surveys the on off state of the current each phase of current transformer for obtaining described net;
Computing unit, for the on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure;
Comparing unit, for described virtual net pressure being compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
Above-mentioned system, preferably, described computing unit comprises:
First computation subunit, for the on off state according to described full middle dc voltage and described current each phase, calculates the voltage that current transformer ac input end surveyed by described net;
Second computation subunit, for the no-load voltage ratio of the voltage according to described net survey current transformer ac input end, leakage inductance and transformer, according to preset formula, calculates virtual net pressure.
Above-mentioned system, preferably, described comparing unit comprises:
Setup unit, for setting the threshold value that isolated island judges;
Judging unit, during for being more than or equal to threshold value that described isolated island judges when described virtual net pressure and the difference of described main-transformer original edge voltage, then judges locomotive generation isolated island fault.
In a kind of locomotive island detection method that the application provides, first, when netting survey current transformer and normally running, main-transformer original edge voltage and full middle dc voltage is gathered; Obtain the on off state that the current each phase of current transformer surveyed by described net; Then, according to the on off state of described full middle dc voltage and described current each phase, according to preset formula, calculate virtual net pressure; Finally, described virtual net pressure is compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judge isolated island fault occurs.The application adopts the island detection method of virtual net pressure, effectively can carry out the detection of locomotive isolated island.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in the embodiment of the present application, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the application, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the process flow diagram of a kind of locomotive island detection method embodiment of the application;
Fig. 2 is the major loop topology diagram of alternating current electric locomotive in the application;
Fig. 3 is the structural representation of a kind of locomotive alone island detection system embodiment of the application.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present application, be clearly and completely described the technical scheme in the embodiment of the present application, obviously, described embodiment is only some embodiments of the present application, instead of whole embodiments.Based on the embodiment in the application, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the application's protection.
With reference to figure 1, show the process flow diagram of a kind of locomotive island detection method of the application embodiment, can comprise the following steps:
Step S101: when netting survey current transformer and normally running, gather main-transformer original edge voltage and full middle dc voltage.
Step S102: obtain the on off state that the current each phase of current transformer surveyed by described net.
Step S103: according to the on off state of described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure.
In the application, the described on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure, comprising:
According to the on off state of described full middle dc voltage and described current each phase, calculate the voltage that current transformer ac input end surveyed by described net.
According to described no-load voltage ratio of netting voltage, leakage inductance and the transformer surveying current transformer ac input end, according to preset formula, calculate virtual net pressure.
Step S104: described virtual net pressure compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
In the application, described pressure by described virtual net compares with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges locomotive generation isolated island fault, comprising:
The threshold value that setting isolated island judges.
When described virtual net pressure and the difference of described main-transformer original edge voltage are more than or equal to the threshold value that described isolated island judges, then judge locomotive generation isolated island fault.
The application make use of the characteristic of net side converter self, build one " virtual net pressure ", this " virtual net pressure " is estimated according to the on off state of self and tractive transformer leakage reactance by net side converter, under locomotive accidental conditions, " virtual net pressure " is substantially consistent with the Traction networks pressure of actual acquisition, but when isolated island occurs, effect is clamped down on due to what there is no a bulk power grid, the voltage magnitude of Traction networks, electric voltage frequency, all can there is certain distortion in the input current of net side converter, thus " the virtual net pressure " derived just and the Traction networks Hair Fixer of actual acquisition give birth to larger difference, utilize this species diversity, just whether locomotive can be in island state to identify.
Fig. 2 shows the major loop topology diagram of alternating current electric locomotive in the application, as can be seen from Figure 2, and U
nfor tractive transformer original edge voltage; U
infor a certain heavy four quadrant convertor AC input voltage; U
dfor the DC voltage on current transformer intermediate dc loop, the input current of net side converter is i
1.
The flow process of the islanding detect in the application is as follows:
When net side converter normally runs, gather tractive transformer original edge voltage U
n, DC voltage U on current transformer intermediate dc loop
d, and in Controling network side converter process, learn the on off state of net side converter, in the system of multiplex, if a certain heavy net side converter A phase on off state is S
a, B phase on off state is S
b, then can obtain the voltage of this heavy net side converter ac input end:
U
in＝(S
a-S
b)*U
d
Suppose that tractive transformer equivalence is L to the leakage inductance size on time limit
in, the no-load voltage ratio of transformer is K
n, then the computing formula of " virtual net pressure " is:
Obtain virtual net pressure U
estiafter, suppose that threshold that isolated island judges is as gate, by judging abs (U
esti-U
n) judge whether to there is isolated island operating mode, as abs (U
esti-U
nduring)>=gate, system generation isolated island fault, abs (U
esti-U
n) < gate time, there is not isolated island fault in system.
In a kind of locomotive island detection method that the application provides, first, when netting survey current transformer and normally running, main-transformer original edge voltage and full middle dc voltage is gathered; Obtain the on off state that the current each phase of current transformer surveyed by described net; Then, according to the on off state of described full middle dc voltage and described current each phase, according to preset formula, calculate virtual net pressure; Finally, described virtual net pressure is compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judge isolated island fault occurs.The application adopts the island detection method of virtual net pressure, effectively can carry out the detection of locomotive isolated island, and be applicable to being applied to locomotive field; Be applicable to the system of power electronic system current transformer; Applicable software algorithm realizes, and possesses actual engineer applied and is worth; The operation of locomotive, the quality of power supply of Traction networks are not affected.
Corresponding with a kind of locomotive island detection method of above-mentioned the application embodiment, see Fig. 3, present invention also provides a kind of locomotive alone island detection system, in this embodiment, this system comprises:
Collecting unit 301, for when netting survey current transformer and normally running, gathers main-transformer original edge voltage and full middle dc voltage.
Acquiring unit 302, surveys the on off state of the current each phase of current transformer for obtaining described net.
Computing unit 303, for the on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure.
Comparing unit 304, for described virtual net pressure being compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
In the application, described computing unit comprises:
First computation subunit, for the on off state according to described full middle dc voltage and described current each phase, calculates the voltage that current transformer ac input end surveyed by described net;
Second computation subunit, for the no-load voltage ratio of the voltage according to described net survey current transformer ac input end, leakage inductance and transformer, according to preset formula, calculates virtual net pressure.
Described comparing unit comprises:
Setup unit, for setting the threshold value that isolated island judges;
Judging unit, during for being more than or equal to threshold value that described isolated island judges when described virtual net pressure and the difference of described main-transformer original edge voltage, then judges locomotive generation isolated island fault.
It should be noted that, each embodiment in this instructions all adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar part mutually see.For device class embodiment, due to itself and embodiment of the method basic simlarity, so description is fairly simple, relevant part illustrates see the part of embodiment of the method.
Finally, also it should be noted that, in this article, the such as relational terms of first and second grades and so on is only used for an entity or operation to separate with another entity or operational zone, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.When not more restrictions, the key element limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment comprising described key element and also there is other identical element.
For convenience of description, various unit is divided into describe respectively with function when describing above device.Certainly, the function of each unit can be realized in same or multiple software and/or hardware when implementing the application.
As seen through the above description of the embodiments, those skilled in the art can be well understood to the mode that the application can add required general hardware platform by software and realizes.Based on such understanding, the technical scheme of the application can embody with the form of software product the part that prior art contributes in essence in other words, this computer software product can be stored in storage medium, as ROM/RAM, magnetic disc, CD etc., comprising some instructions in order to make a computer equipment (can be personal computer, server, or the network equipment etc.) perform the method described in some part of each embodiment of the application or embodiment.
A kind of locomotive island detection method provided the application above and system are described in detail, apply specific case herein to set forth the principle of the application and embodiment, the explanation of above embodiment is just for helping method and the core concept thereof of understanding the application; Meanwhile, for one of ordinary skill in the art, according to the thought of the application, all will change in specific embodiments and applications, in sum, this description should not be construed as the restriction to the application.
Claims (6)
1. a locomotive island detection method, is characterized in that, the method comprises:
When netting survey current transformer and normally running, gather main-transformer original edge voltage and full middle dc voltage;
Obtain the on off state that the current each phase of current transformer surveyed by described net;
According to the on off state of described full middle dc voltage and described current each phase, according to preset formula, calculate virtual net pressure;
Described virtual net pressure is compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
2. method according to claim 1, is characterized in that, the described on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure, comprising:
According to the on off state of described full middle dc voltage and described current each phase, calculate the voltage that current transformer ac input end surveyed by described net;
According to described no-load voltage ratio of netting voltage, leakage inductance and the transformer surveying current transformer ac input end, according to preset formula, calculate virtual net pressure.
3. method according to claim 1, it is characterized in that, described pressure by described virtual net compares with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judge locomotive generation isolated island fault, comprising:
The threshold value that setting isolated island judges;
When described virtual net pressure and the difference of described main-transformer original edge voltage are more than or equal to the threshold value that described isolated island judges, then judge locomotive generation isolated island fault.
4. a locomotive alone island detection system, is characterized in that, this system comprises:
Collecting unit, for when netting survey current transformer and normally running, gathers main-transformer original edge voltage and full middle dc voltage;
Acquiring unit, surveys the on off state of the current each phase of current transformer for obtaining described net;
Computing unit, for the on off state according to described full middle dc voltage and described current each phase, according to preset formula, calculates virtual net pressure;
Comparing unit, for described virtual net pressure being compared with described main-transformer original edge voltage, when described virtual net pressure meets pre-conditioned with the difference of described main-transformer original edge voltage, then judges isolated island fault occurs.
5. system according to claim 4, is characterized in that, described computing unit comprises:
First computation subunit, for the on off state according to described full middle dc voltage and described current each phase, calculates the voltage that current transformer ac input end surveyed by described net;
Second computation subunit, for the no-load voltage ratio of the voltage according to described net survey current transformer ac input end, leakage inductance and transformer, according to preset formula, calculates virtual net pressure.
6. system according to claim 4, is characterized in that, described comparing unit comprises:
Setup unit, for setting the threshold value that isolated island judges;
Judging unit, during for being more than or equal to threshold value that described isolated island judges when described virtual net pressure and the difference of described main-transformer original edge voltage, then judges locomotive generation isolated island fault.
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