CN202815147U - System for determining fault branch in which alternating current is connected in direct current system - Google Patents
System for determining fault branch in which alternating current is connected in direct current system Download PDFInfo
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- CN202815147U CN202815147U CN 201220381991 CN201220381991U CN202815147U CN 202815147 U CN202815147 U CN 202815147U CN 201220381991 CN201220381991 CN 201220381991 CN 201220381991 U CN201220381991 U CN 201220381991U CN 202815147 U CN202815147 U CN 202815147U
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Abstract
The utility model relates to a system for determining a fault branch in which alternating current is connected in a direct current system. The system comprises a fault diagnostic device and several fault positioning devices, wherein the fault diagnostic device comprises an online monitoring device, input of which is connected with DC bus anode KM+, DC bus cathode KM- and ground GND; the several fault positioning devices are respectively installed in each DC branch; the online monitoring device is connected with the fault positioning devices through communication bus; and the online monitoring device acquires alternating voltage which is connected in the direct current system at real time and monitors the fault of alternating current connected in the direct current system. When alternating voltage value exceeds a set threshold value, the fault is determined, and the fault branch is judged through the fault positioning devices. According to the utility model, there is no need to increase construction of an AC sensor and system cost is saved. In the meantime, as there is no signal injection in the scheme, direct current system corrugation will not be increased, problems such as relay protection mal operation, breaker mistrip and the like will not be caused, and reliability is higher.
Description
Technical field
The utility model relates to a kind ofly can determine that alternating current seals in the system of dc system fault branch road, belongs to direct current IT system monitoring field.
Background technology
In electric system, the reliability service of direct supply plays a very important role security of system is stable, because the wearing and tearing of AC and DC cable in long-time running, or the damage of AC and DC device components and parts, or manual operation accidentally, can cause alternating current to seal in straight-flow system.Accident in generating plant and transformer station's generation showed in recent years, after alternating current seals in straight-flow system, cause easily protective relaying maloperation or isolating switch false tripping, such as " the AC in the DC loop causes the analysis of causes of switch trip " (relay, the 14th phase in 2007) the accident overview of generating plant, Xibaipo 220kV booster stations intermediate switch tripping operation introduced in a literary composition, and analyzed alternating current and seal in after the DC loop the impact of relay protection, method and measure proposed; " the 220V industrial frequency AC is sneaked into the switch mis-jumping case study that DC control circuit causes " (Shandong Electric Power Group technology, the 4th phase in 2009) literary composition has been introduced Laiwu power plant because the industrial frequency AC that electric arc causes seals in the failure condition that DC control circuit causes station-service Backup Power Switch false switching, find the reason of problem by test, inspection and analysis, and taked corresponding the processing and the precautionary measures; " analysis of straight-flow system is scurried in interchange " (direct supply technology, the 1st phase in 2011) literary composition to two power plant since the accident phenomenon that causes of the AC in the DC system analyze and describe.
At present, for the employed D.C. isolation monitoring device in generating plant and transformer station, the following two kinds of methods of general employing are carried out earthing wire-selecting, one is the signal injection method, namely producing an alternating signal injects between straight-flow system and the earth, the branch road that ground connection occurs just can consist of the loop with this alternating signal source, is installed on the fault branch that the sensor that can measure alternating current on each branch road is located ground connection by detection; It two is the DC leakage current method, because the D.C. isolation monitoring device is provided with balanced bridge and unbalanced bridge, the branch road that ground connection occurs must produce leakage current, is installed on the fault branch that the sensor that can measure DC leakage current on each branch road is located ground connection by detection.
After alternating current sealed in straight-flow system, alternating voltage can be added on the DC voltage, can judge whether that fault occurs by the voltage waveform that detects on the dc bus.For the D.C. isolation monitoring device that adopts the signal injection method, can exchange the branch road that seals in the fault generation by whether existing alternating current to locate on the detection branch; And for the insulation monitoring and warning device that adopts the DC leakage current method, because the DC leakage current sensor can't detect alternating current, so can't realize the localization of fault that alternating current seals in.Because the injection of signal causes the increase of straight-flow system ripple, the normal problems such as protective relaying maloperation, isolating switch mistrip of bringing for straight-flow system, straight-flow system and relay protection system had potential safety hazard, so adopt the D.C. isolation monitoring device of signal injection method to eliminate gradually; And the D.C. isolation monitoring device of employing DC leakage current method, because need are set up the localization of fault that ac sensor could realize that alternating current seals at each branch road, so increased the cost of system.
The utility model content
The purpose of this utility model provides a kind ofly can determine that alternating current seals in the system of dc system fault branch road, and it can determine that alternating current seals in the dc system fault branch road in the D.C. isolation monitoring device that adopts the DC leakage current method.
Technical solution of the present utility model is:
A kind of definite alternating current seals in the system of dc system fault branch road, comprise failure judgment device and some fault locators, wherein: described failure judgment device comprises online monitoring device, and its input links to each other with dc bus anodal KM+, dc bus negative pole KM-and the earth GND; Some fault locators are installed in respectively in each direct current branch, and online monitoring device is connected by communication bus with fault locator; Online monitoring device Real-time Collection seals in the alternating voltage of straight-flow system, alternating current is sealed in dc system fault monitor, and judges after ac voltage is above the threshold value of setting and breaks down, and carry out the judgement of fault branch by fault locator.
Further:
Described online monitoring device comprises electric bridge unit, DC voltage detection and conditioning unit, alternating voltage detection and conditioning unit, AD converter, processor, communicating circuit unit, wherein: the input end of electric bridge unit is connected between the positive pole of straight-flow system, negative pole and the earth, the electric bridge unit takes out the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground is given DC voltage detection and conditioning unit, and the electric bridge unit takes out the alternating voltage that seals in straight-flow system and gives alternating voltage detection and conditioning unit; DC voltage detects with conditioning unit and detects the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground, alternating voltage detects with conditioning unit and detects the alternating voltage that seals in straight-flow system, the DC voltage detection detects with conditioning unit with conditioning unit and alternating voltage and is responsible for respectively the dc voltage value of obtaining is nursed one's health into analog electrical energy with ac voltage, and exports to AD converter; DC voltage and alternating voltage after AD converter will be nursed one's health are converted to digital signal, and export to processor; Processor is by computing, obtain anodal voltage-to-ground U+, the negative pole voltage-to-ground U-of straight-flow system, and the alternating voltage Uac that seals in straight-flow system, this anodal voltage-to-ground U+, negative pole voltage-to-ground U-and the alternating voltage Uac that seals in straight-flow system are as judging whether to exchange the foundation that seals in; Communicating circuit unit and described fault locator are carried out communication, and the information of read failure locating device is as judging the foundation that the AC in the DC fault branch occurs.
Described fault locator comprises mutual inductor, DC leakage current measuring unit, processor, communicating circuit unit, and wherein: two of the straight-flow system branch road connect respectively dc bus wire anodal and the dc bus negative pole and pass mutual inductor; The input of DC leakage current measuring unit links to each other with mutual inductor, and the output reflection of DC leakage current measuring unit is passed the pulse signal of the leakage current of circuit of mutual inductor and direction or simulating signal to processor; Processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and processor is transferred to online monitoring device with size and the direction of leakage current by the communicating circuit unit.
Described fault locator comprises localization of fault signal pickup assembly and some Fisrt fault locating devices, wherein: the Fisrt fault locating device is converted to analog quantity or digital quantity with the DC leakage current that branch road produces, the localization of fault signal pickup assembly gathers analog quantity or the digital quantity of each Fisrt fault locating device output, and exports to online monitoring device.
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, and the DC leakage current that the DC leakage current measuring unit will pass in two wires of straight-flow system branch road of mutual inductor is converted to analog signal output to described localization of fault signal pickup assembly; Described localization of fault signal pickup assembly comprises processor, at least one AD converter, communicating circuit unit, AD converter is digital signal with the analog signal conversion of Fisrt fault locating device output, processor calculates the DC leakage current value of each branch road according to the output of AD converter, the DC leakage current value of each branch road is transmitted in communicating circuit unit and online monitoring device communication.
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, first processor, communicating circuit unit, the DC leakage current measuring unit links to each other with mutual inductor, output reflects the leakage current of the straight-flow system branch road that passes mutual inductor and pulse signal or the simulating signal of direction, and inputs to first processor; First processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and the size of leakage current and direction are transferred to described localization of fault signal pickup assembly by the communicating circuit unit; Described localization of fault signal pickup assembly comprises the first communicating circuit unit, the second processor, the second communicating circuit unit, the first communicating circuit unit is by communicating circuit unit and the communication of Fisrt fault locating device of Fisrt fault locating device, receive the DC leakage current information that the Fisrt fault locating device transmits, the second processor gathers the leakage current information of all branch roads, and is transferred to online monitoring device by the second communicating circuit unit.
The utility model adopts such scheme, in the D.C. isolation monitoring device that adopts the DC leakage current method, can determine that alternating current seals in the dc system fault branch road; Need not to set up ac sensor, save system cost, this programme no signal is injected simultaneously, therefore can not cause the increase of straight-flow system ripple, can not cause the problems such as protective relaying maloperation, isolating switch mistrip, and reliability is higher.
Description of drawings
Fig. 1 is the whole theory diagram of implementation system.
Fig. 2 is working-flow figure.
Fig. 3 is that the online monitoring device in the whole schematic diagram of implementation system of the present utility model is implemented schematic diagram.
Fig. 4 is the theory diagram of the fault locator embodiment 1 in the whole schematic diagram of implementation system of the present utility model.
Fig. 5 is the theory diagram of the fault locator embodiment 2 in the whole schematic diagram of implementation system of the present utility model.
Fig. 6 is the theory diagram of the embodiment a of fault locator 1 and fault locator 2 among the fault locator embodiment 2 of the present utility model.
Fig. 7 is the theory diagram of the embodiment b of fault locator 1 and fault locator 2 among the fault locator embodiment 2 of the present utility model.
Embodiment
The utility model relates to a kind ofly can determine that alternating current seals in the system of dc system fault branch road.
System of the present utility model comprises failure judgment device and some fault locators, and wherein: failure judgment device comprises online monitoring device, and its input links to each other with dc bus anodal KM+, dc bus negative pole KM-and the earth GND; Some fault locators are installed in respectively in each direct current branch, and online monitoring device is connected by communication bus with fault locator; Online monitoring device Real-time Collection seals in the alternating voltage of straight-flow system, alternating current is sealed in dc system fault monitor, and judges after ac voltage is above the threshold value of setting and breaks down, and carry out the judgement of fault branch by fault locator.
Described online monitoring device comprises electric bridge unit, DC voltage detection and conditioning unit, alternating voltage detection and conditioning unit, AD converter, processor, communicating circuit unit, wherein: the input end of electric bridge unit is connected between the positive pole of straight-flow system, negative pole and the earth, the electric bridge unit takes out the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground is given DC voltage detection and conditioning unit, and the electric bridge unit takes out the alternating voltage that seals in straight-flow system and gives alternating voltage detection and conditioning unit; DC voltage detects with conditioning unit and detects the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground, alternating voltage detects with conditioning unit and detects the alternating voltage that seals in straight-flow system, the DC voltage detection detects with conditioning unit with conditioning unit and alternating voltage and is responsible for respectively the dc voltage value of obtaining is nursed one's health into analog electrical energy with ac voltage, and exports to AD converter; DC voltage and alternating voltage after AD converter will be nursed one's health are converted to digital signal, and export to processor; Processor is by computing, obtain anodal voltage-to-ground U+, the negative pole voltage-to-ground U-of straight-flow system, and the alternating voltage Uac that seals in straight-flow system, this anodal voltage-to-ground U+, negative pole voltage-to-ground U-and the alternating voltage Uac that seals in straight-flow system are as judging whether to exchange the foundation that seals in; Communicating circuit unit and described fault locator are carried out communication, and the information of read failure locating device is as judging the foundation that the AC in the DC fault branch occurs.
Described fault locator comprises mutual inductor, DC leakage current measuring unit, processor, communicating circuit unit, and wherein: two of the straight-flow system branch road connect respectively dc bus wire anodal and the dc bus negative pole and pass mutual inductor; The input of DC leakage current measuring unit links to each other with mutual inductor, and the output reflection of DC leakage current measuring unit is passed the pulse signal of the leakage current of circuit of mutual inductor and direction or simulating signal to processor; Processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and processor is transferred to online monitoring device with size and the direction of leakage current by the communicating circuit unit.
Described fault locator comprises localization of fault signal pickup assembly and some Fisrt fault locating devices, wherein: the Fisrt fault locating device is converted to analog quantity or digital quantity with the DC leakage current that branch road produces, the localization of fault signal pickup assembly gathers analog quantity or the digital quantity of each Fisrt fault locating device output, and exports to online monitoring device.
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, and the DC leakage current that the DC leakage current measuring unit will pass in two wires of straight-flow system branch road of mutual inductor is converted to analog signal output to described localization of fault signal pickup assembly; Described localization of fault signal pickup assembly comprises processor, at least one AD converter, communicating circuit unit, AD converter is digital signal with the analog signal conversion of Fisrt fault locating device output, processor calculates the DC leakage current value of each branch road according to the output of AD converter, the DC leakage current value of each branch road is transmitted in communicating circuit unit and online monitoring device communication.
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, first processor, communicating circuit unit, the DC leakage current measuring unit links to each other with mutual inductor, output reflects the leakage current of the straight-flow system branch road that passes mutual inductor and pulse signal or the simulating signal of direction, and inputs to first processor; First processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and the size of leakage current and direction are transferred to described localization of fault signal pickup assembly by the communicating circuit unit; Described localization of fault signal pickup assembly comprises the first communicating circuit unit, the second processor, the second communicating circuit unit, the first communicating circuit unit is by communicating circuit unit and the communication of Fisrt fault locating device of Fisrt fault locating device, receive the DC leakage current information that the Fisrt fault locating device transmits, the second processor gathers the leakage current information of all branch roads, and is transferred to online monitoring device by the second communicating circuit unit.
For making the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with specific embodiments and the drawings, the utility model is further described.
Fig. 1 is the whole theory diagram of implementation system of the present utility model.As shown in Figure 1, this system is comprised of two parts, i.e. failure judgment device and fault locator.Failure judgment device comprises online monitoring device, and its 3 input ends link to each other with dc bus anodal KM+, dc bus negative pole KM-and the earth GND respectively; Some fault locators are installed in respectively in each direct current branch, and the positive pole of direct current branch and negative pole pass the built-in mutual inductor of fault locator simultaneously; Online monitoring device is connected by communication bus with fault locator.Online monitoring device Real-time Collection seals in the alternating voltage of straight-flow system, alternating current is sealed in dc system fault monitors, after ac voltage is above the threshold value of setting, judge and break down, carry out the judgement of fault branch, i.e. route selection by fault locator.
Fig. 2 is the workflow diagram of native system.Its workflow is:
1) online monitoring device detects the anodal voltage-to-ground U of dc bus in real time
+, negative pole voltage-to-ground U
-, the alternating voltage U that seals in
Ac, and judge, work as U
AcGreater than setting value U
AcaThe time, determine that straight-flow system generation alternating current seals in fault;
2) to the anodal voltage-to-ground U of the dc bus of this moment
+With negative pole voltage-to-ground U
-Compare, work as U
-During≤Δ U (Δ U is setting value), judge that alternating current seals in straight-flow system by negative pole; Work as U
+During≤Δ U (Δ U is setting value), judge that alternating current seals in straight-flow system by positive pole; If above-mentioned condition all is false, then the polarity of the AC in the DC system is not judged.
3) online monitoring device reads the leakage current value of the fault locator measurement that is installed on each branch road, the line ordering of going forward side by side, and wherein the leakage current value maximum branch road is the branch road that alternating current seals in.
Fig. 3 is that the online monitoring device in the whole schematic diagram of implementation system of the present utility model is implemented schematic diagram.As shown in Figure 3, online monitoring device comprises electric bridge unit, DC voltage detection and conditioning unit, alternating voltage detection and conditioning unit, AD converter, processor, communicating circuit unit.Wherein: the input end of electric bridge unit is connected between the positive pole of straight-flow system, negative pole and the earth, the electric bridge unit takes out the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground is given DC voltage detection and conditioning unit, and the electric bridge unit takes out the alternating voltage that seals in straight-flow system and gives alternating voltage detection and conditioning unit.DC voltage detects with conditioning unit and detects the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground, alternating voltage detects with conditioning unit and detects the alternating voltage that seals in straight-flow system, the DC voltage detection detects the dc voltage value of being responsible for respectively obtaining with conditioning unit with conditioning unit and alternating voltage and nurses one's health into the analog electrical energy that is fit to AD converter with ac voltage, and exports to AD converter.DC voltage and alternating voltage after AD converter will be nursed one's health are converted to digital signal, and export to processor.Processor obtains anodal voltage-to-ground U+, the negative pole voltage-to-ground U-of straight-flow system by computing (operational formula sees below), and the alternating voltage Uac that seals in straight-flow system.This anodal voltage-to-ground U+, negative pole voltage-to-ground U-and the alternating voltage Uac that seals in straight-flow system are as judging whether to exchange the foundation that seals in.Communicating circuit unit and fault locator are carried out communication, and the information of read failure locating device is as judging the foundation that the AC in the DC fault branch occurs.Every online monitoring device generally is connected with many fault locators.
The electric bridge unit comprises null-type bridge circuit at least, namely between dc bus positive pole and the earth, access respectively resistance or resistance string that resistance equates between dc bus negative pole and the earth, balanced bridge is used for detection that the balance of the anodal voltage-to-ground of dc bus and negative pole voltage-to-ground, the insulation of straight-flow system one pole are descended.
The following describes the anodal voltage-to-ground U+, the negative pole voltage-to-ground U-that obtain straight-flow system, and the alternating voltage Uac that seals in straight-flow system.Operational formula:
For the calculating of DC voltage, generally by the acquisition of averaging, its computation process is as follows:
In sampling period T, gather the magnitude of voltage U of n point
1, U
2... U
n, then average voltage is
Wherein, k is the constant of calibration usefulness,
For the calculating of alternating voltage, generally obtain by getting root-mean-square value, its computation process is as follows:
In sampling period T, gather the magnitude of voltage U of n point
1, U
2... U
n, then rms voltage is
Wherein, k is the constant of calibration usefulness.
In this embodiment, DC voltage detects and the input of conditioning unit also can directly connect and the earth, dc bus negative pole and the earth anodal from dc bus, and alternating voltage detects and the input of conditioning unit also can directly connect and the earth, dc bus negative pole and the earth anodal from dc bus; AD converter can be integrated in the processor, also can be AD converter independently.
Fig. 4 is the theory diagram of the fault locator embodiment 1 in the whole schematic diagram of implementation system of the present utility model.As shown in Figure 4, the fault locator of this embodiment comprises mutual inductor, DC leakage current measuring unit, processor, display circuit unit, communicating circuit unit.Wherein: two wires that connect respectively dc bus positive pole and dc bus negative pole of straight-flow system branch road pass mutual inductor, and the current polarity of two wires of the mutual inductor of flowing through is opposite.The input of DC leakage current measuring unit links to each other with mutual inductor, and DC leakage current measuring unit output can reflect that the pulse signal of the leakage current of the circuit that passes mutual inductor and direction or simulating signal are to processor.If pulse signal, processor is determined leakage current and direction by the variation that detects pulse width, if simulating signal, processor is then determined leakage current and direction by the amplitude that detects simulating signal.Processor is transferred to online monitoring device with size and the direction of leakage current by the communicating circuit unit.It is set that this line state is observed for ease of the user in the display circuit unit, generally comprises the parts such as pilot lamp, charactron or liquid crystal display.
DC leakage current measuring unit principle of work: consist of oscillatory circuit by mutual inductor second siding ring and some electronic devices and components, produce waveform, the DC leakage current value of passing mutual inductor can reflect indirectly by positive pulsewidth and the negative pulsewidth of waveform.Can obtain the DC leakage current value by positive pulsewidth and the negative pulse width variations that detects the wave of oscillation.
Because the fault locator of this embodiment adopts the connected mode of communication bus, so fault locator is comparatively easy with being connected of online monitoring device, it is comparatively convenient to safeguard.
Fig. 5 is the theory diagram of the fault locator embodiment 2 in the whole schematic diagram of implementation system of the present utility model.As shown in Figure 5, the fault locator of this embodiment comprises fault locator 1 and localization of fault signal pickup assembly 2, wherein, fault locator 1 can be converted to analog quantity or digital quantity with the DC leakage current that branch road produces, localization of fault signal pickup assembly 2 gathers analog quantity or the digital quantity of fault locator 1 output, and exports to online monitoring device.In general, every localization of fault signal pickup assembly 2 can connect many fault locators 1, is not less than at least 2.
Since adopt the fault locator of this embodiment, can be in the straight-flow system of multiple branch circuit, and the multiple branch circuit that position relationship is nearer carries out unified management, so can reduce to a certain extent the time of localization of fault.
Fig. 6 is the embodiment a theory diagram of fault locator 1 and localization of fault signal pickup assembly 2 in the fault locator embodiment 2 in the embodiment of the present utility model.In this embodiment, fault locator 1 comprises mutual inductor, DC leakage current measuring unit.The DC leakage current that the DC leakage current measuring unit will pass in two wires of straight-flow system branch road of mutual inductor is converted to analog signal output to localization of fault signal pickup assembly 2.Localization of fault signal pickup assembly 2 comprises processor, at least one AD converter, communicating circuit unit.Wherein, AD converter is with the analog signal conversion of the fault locator 1 output digital signal for being identified by processor, processor calculates the DC leakage current value of each branch road according to the output of AD converter, the DC leakage current value of each branch road is transmitted in communicating circuit unit and online monitoring device communication.AD converter can be integrated in the processor, also can be freestanding AD converter.
Fig. 7 is the embodiment b theory diagram of fault locator 1 and localization of fault signal pickup assembly 2 in the fault locator embodiment 2 in the embodiment of the present utility model.In this embodiment, fault locator 1 comprises mutual inductor, DC leakage current measuring unit, processor, communicating circuit unit.The DC leakage current measuring unit links to each other with mutual inductor, and output reflects the leakage current of the straight-flow system branch road that passes mutual inductor and pulse signal or the simulating signal of direction, and inputs to processor; If pulse signal, processor need to be determined leakage current and direction by the variation that detects pulse width, if simulating signal, processor needs to determine leakage current and direction by the amplitude that detects simulating signal; The size of leakage current and direction are transferred to localization of fault signal pickup assembly 2 by the communicating circuit unit.Localization of fault signal pickup assembly 2 comprises communicating circuit unit 1, processor, communicating circuit unit 2.Wherein, communicating circuit unit 1 and fault locator 1 communication receive the DC leakage current information that fault locator 1 transmits, and processor gathers the leakage current information of all branch roads, and is transferred to online monitoring device by communicating circuit unit 2.
Claims (6)
1. a definite alternating current seals in the system of dc system fault branch road, it is characterized in that comprising failure judgment device and some fault locators, wherein:
Described failure judgment device comprises online monitoring device, and its input links to each other with dc bus anodal KM+, dc bus negative pole KM-and the earth GND;
Some fault locators are installed in respectively in each direct current branch, and online monitoring device is connected by communication bus with fault locator;
Online monitoring device Real-time Collection seals in the alternating voltage of straight-flow system, alternating current is sealed in dc system fault monitor, and judges after ac voltage is above the threshold value of setting and breaks down, and carry out the judgement of fault branch by fault locator.
2. definite alternating current as claimed in claim 1 seals in the system of dc system fault branch road, it is characterized in that:
Described online monitoring device comprises electric bridge unit, DC voltage detection and conditioning unit, alternating voltage detection and conditioning unit, AD converter, processor, communicating circuit unit, wherein:
The input end of electric bridge unit is connected between positive pole, negative pole and the earth of straight-flow system, the electric bridge unit takes out the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground is given DC voltage detection and conditioning unit, and the electric bridge unit takes out the alternating voltage that seals in straight-flow system and gives alternating voltage detection and conditioning unit;
DC voltage detects with conditioning unit and detects the anodal voltage-to-ground of dc bus and dc bus negative pole voltage-to-ground, alternating voltage detects with conditioning unit and detects the alternating voltage that seals in straight-flow system, the DC voltage detection detects with conditioning unit with conditioning unit and alternating voltage and is responsible for respectively the dc voltage value of obtaining is nursed one's health into analog electrical energy with ac voltage, and exports to AD converter;
DC voltage and alternating voltage after AD converter will be nursed one's health are converted to digital signal, and export to processor;
Processor is by computing, obtain anodal voltage-to-ground U+, the negative pole voltage-to-ground U-of straight-flow system, and the alternating voltage Uac that seals in straight-flow system, this anodal voltage-to-ground U+, negative pole voltage-to-ground U-and the alternating voltage Uac that seals in straight-flow system are as judging whether to exchange the foundation that seals in;
Communicating circuit unit and described fault locator are carried out communication, and the information of read failure locating device is as judging the foundation that the AC in the DC fault branch occurs.
3. definite alternating current as claimed in claim 1 or 2 seals in the system of dc system fault branch road, it is characterized in that described fault locator comprises mutual inductor, DC leakage current measuring unit, processor, communicating circuit unit, wherein:
Two of the straight-flow system branch road connect respectively dc bus wire anodal and the dc bus negative pole and pass mutual inductor;
The input of DC leakage current measuring unit links to each other with mutual inductor, and the output reflection of DC leakage current measuring unit is passed the pulse signal of the leakage current of circuit of mutual inductor and direction or simulating signal to processor;
Processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and processor is transferred to online monitoring device with size and the direction of leakage current by the communicating circuit unit.
4. definite alternating current as claimed in claim 1 or 2 seals in the system of dc system fault branch road, it is characterized in that described fault locator comprises localization of fault signal pickup assembly and some Fisrt fault locating devices, wherein:
The Fisrt fault locating device is converted to analog quantity or digital quantity with the DC leakage current that branch road produces, and the localization of fault signal pickup assembly gathers analog quantity or the digital quantity of each Fisrt fault locating device output, and exports to online monitoring device.
5. definite alternating current as claimed in claim 4 seals in the system of dc system fault branch road, it is characterized in that:
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, and the DC leakage current that the DC leakage current measuring unit will pass in two wires of straight-flow system branch road of mutual inductor is converted to analog signal output to described localization of fault signal pickup assembly;
Described localization of fault signal pickup assembly comprises processor, at least one AD converter, communicating circuit unit, AD converter is digital signal with the analog signal conversion of Fisrt fault locating device output, processor calculates the DC leakage current value of each branch road according to the output of AD converter, the DC leakage current value of each branch road is transmitted in communicating circuit unit and online monitoring device communication.
6. definite alternating current as claimed in claim 4 seals in the system of dc system fault branch road, it is characterized in that:
Described Fisrt fault locating device comprises mutual inductor, DC leakage current measuring unit, first processor, communicating circuit unit, the DC leakage current measuring unit links to each other with mutual inductor, output reflects the leakage current of the straight-flow system branch road that passes mutual inductor and pulse signal or the simulating signal of direction, and inputs to first processor; First processor is determined leakage current and direction by the variation of detection pulse width or by the amplitude that detects simulating signal, and the size of leakage current and direction are transferred to described localization of fault signal pickup assembly by the communicating circuit unit;
Described localization of fault signal pickup assembly comprises the first communicating circuit unit, the second processor, the second communicating circuit unit, the first communicating circuit unit is by communicating circuit unit and the communication of Fisrt fault locating device of Fisrt fault locating device, receive the DC leakage current information that the Fisrt fault locating device transmits, the second processor gathers the leakage current information of all branch roads, and is transferred to online monitoring device by the second communicating circuit unit.
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| CN 201220381991 CN202815147U (en) | 2012-08-02 | 2012-08-02 | System for determining fault branch in which alternating current is connected in direct current system |
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| CN 201220381991 CN202815147U (en) | 2012-08-02 | 2012-08-02 | System for determining fault branch in which alternating current is connected in direct current system |
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| CN103558507A (en) * | 2013-10-29 | 2014-02-05 | 国家电网公司 | Sensor for direct current fault line selection and alternating current interlarding line selection |
| CN103576052A (en) * | 2012-08-02 | 2014-02-12 | 北京人民电器厂有限公司 | System and method for determining direct-current system fault branch circuits needing to be in in-series connection with alternating currents |
| CN103592563A (en) * | 2013-11-22 | 2014-02-19 | 国家电网公司 | Direct current system insulation on-line monitoring device |
| CN104330681A (en) * | 2013-07-22 | 2015-02-04 | 艾默生网络能源有限公司 | Device for detecting AC entering DC bus in DC power system |
| CN104459291A (en) * | 2014-12-15 | 2015-03-25 | 南车株洲电力机车有限公司 | Method and system for detecting AC signals of specific frequency |
| CN105988046A (en) * | 2015-02-12 | 2016-10-05 | 深圳奥特迅电力设备股份有限公司 | Detection method and detection system for judging alternating current signals being in series connection with direct current system |
| CN107515356A (en) * | 2017-10-23 | 2017-12-26 | 华北电力大学（保定） | A kind of DC distribution net system and its method for diagnosing faults |
| CN117233532A (en) * | 2023-09-21 | 2023-12-15 | 中科智寰(北京)科技有限公司 | DC power grid ground fault on-line positioning and protecting system |
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2012
- 2012-08-02 CN CN 201220381991 patent/CN202815147U/en not_active Withdrawn - After Issue
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103576052A (en) * | 2012-08-02 | 2014-02-12 | 北京人民电器厂有限公司 | System and method for determining direct-current system fault branch circuits needing to be in in-series connection with alternating currents |
| CN103576052B (en) * | 2012-08-02 | 2016-09-14 | 北京人民电器厂有限公司 | Determine that alternating current seals in the system and method for DC system fault branch road |
| CN103308866A (en) * | 2013-06-04 | 2013-09-18 | 安徽省电力公司阜阳供电公司 | Direct current insulation on-line monitoring device of transformer substation |
| CN104330681A (en) * | 2013-07-22 | 2015-02-04 | 艾默生网络能源有限公司 | Device for detecting AC entering DC bus in DC power system |
| CN104330681B (en) * | 2013-07-22 | 2017-08-29 | 艾默生网络能源有限公司 | Dc bus scurries into the detection means of exchange in a kind of DC power system |
| CN103558507A (en) * | 2013-10-29 | 2014-02-05 | 国家电网公司 | Sensor for direct current fault line selection and alternating current interlarding line selection |
| CN103592563A (en) * | 2013-11-22 | 2014-02-19 | 国家电网公司 | Direct current system insulation on-line monitoring device |
| CN104459291A (en) * | 2014-12-15 | 2015-03-25 | 南车株洲电力机车有限公司 | Method and system for detecting AC signals of specific frequency |
| CN105988046A (en) * | 2015-02-12 | 2016-10-05 | 深圳奥特迅电力设备股份有限公司 | Detection method and detection system for judging alternating current signals being in series connection with direct current system |
| CN107515356A (en) * | 2017-10-23 | 2017-12-26 | 华北电力大学（保定） | A kind of DC distribution net system and its method for diagnosing faults |
| CN117233532A (en) * | 2023-09-21 | 2023-12-15 | 中科智寰(北京)科技有限公司 | DC power grid ground fault on-line positioning and protecting system |
| CN117233532B (en) * | 2023-09-21 | 2024-02-09 | 中科智寰(北京)科技有限公司 | DC power grid ground fault on-line positioning and protecting system |
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