CN203455412U - DC system insulation monitoring device - Google Patents
DC system insulation monitoring device Download PDFInfo
- Publication number
- CN203455412U CN203455412U CN201320605708.0U CN201320605708U CN203455412U CN 203455412 U CN203455412 U CN 203455412U CN 201320605708 U CN201320605708 U CN 201320605708U CN 203455412 U CN203455412 U CN 203455412U
- Authority
- CN
- China
- Prior art keywords
- cpu processor
- circuit
- sampling resistor
- ground
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
Images
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The utility model discloses a monitoring device, and particularly relates to a DC system insulation monitoring device. The device is specifically for insulation monitoring and positioning when there is AC intrusion to a DC system. The device comprises a first CPU, a second CPU, and a third CPU. The first CPU is connected to the second CPU via a dual-port RAM, and the second CPU is connected to the third CPU via an RS458 interface. The first CPU is connected to a first sampling circuit and a DC voltage input circuit; the second CPU is connected to an LCD circuit and a memory; and the third CPU is connected to a second sampling circuit and a branch sensor input circuit. When an AC intrusion fault happens in a DC system, the device can monitor the insulation resistance of the DC system, locate a fault branch, and calculate the AC input impedance of the branch where the AC intrusion happens. When there is no AC intrusion fault, the device can monitor the insulation resistance of the DC system and locate branches with reduced insulation, so that it is convenient for on-site staff to carry out maintenance for safe running of the DC system.
Description
Technical field
The utility model discloses a kind of monitoring device, and particularly insulating monitoring and the location while scurrying into occurs to exchange for a kind of Insulation Inspection Device for Direct-Current System, especially straight-flow system.
Background technology
The safe and reliable operation of direct supply is most important for the safe and reliable operation of transformer station.But because DC power supply equipment is many, power cable is long, in actual motion, often there is the faults such as DC earthing.Although straight-flow system is moved floatingly, single-point grounding does not affect the normal operation of system, and looking up the fault is eliminated as early as possible, otherwise while there is second point ground connection, will cause relay or protective device misoperation, leads to grave consequences.At present, in transformer station, generally use straight-flow system insulation and line selection apparatus, played good effect.
In actual motion, there is a kind of special earth fault destructiveness larger, Here it is, and alternating current is scurried into straight-flow system.Due to existing alternating current in a screen cabinet, there is again direct current, power cable is longer again, and alternating current-direct current terminal is separated by nearer, often can cause alternating current to scurry into straight-flow system because mis-wired or insulation reduce, and causes insulation monitoring and warning device report DC ground fault.When this fault is serious, can cause device damage, or protection equipment malfunction, to substation safety, operation brings and has a strong impact on.Straight-flow system is scurried in interchange can be divided into two classes substantially, and a class is that alternating current is directly linked into straight-flow system, and another kind of is that alternating current accesses straight-flow system by resistive load.Substation field lacks effective monitoring means and fault warning measure to " DC Line Fault is scurried in interchange " at present, and being difficult to especially distinguish is that the interchange that any situation occurs is scurried on earth.
Utility model content
According to above deficiency of the prior art, problem to be solved in the utility model is: provide a kind of interchange that can effectively monitor straight-flow system to scurry into fault, accurately location exchanges and scurries into branch road, and can calculate the system insulating resistance that exchanges while scurrying into direct current and the Insulation Inspection Device for Direct-Current System of branch road insulation resistance.
The utility model solves the technical scheme that its technical matters adopts:
Described Insulation Inspection Device for Direct-Current System, comprise a CPU processor, the 2nd CPU processor and the 3rd CPU processor, the one CPU processor connects the 2nd CPU processor by two-port RAM, the 2nd CPU processor connects the 3rd CPU processor by RS458 interface, the one CPU processor connects the first sample circuit and DC voltage input circuit, the 2nd CPU processor connects liquid crystal display circuit and storer, and the 3rd CPU processor connects the second sample circuit and branch sensor input circuit.
The one CPU processor of Insulation Inspection Device for Direct-Current System is controlled the first sample circuit, and carries out data calculating and processing, final data is passed to the 2nd CPU processor by two-port RAM simultaneously; The 2nd CPU processor controls liquid crystal display circuit, be responsible for and the data interaction of storer, be responsible for carrying out data communication with the 3rd CPU processor simultaneously, the 3rd CPU processor is responsible for controlling the second sample circuit, and by RS485 interface, carries out data communication with the 2nd CPU processor.Liquid crystal adopts serial port liquid crystal screen, and liquid crystal display is controlled by the communication interface of the 2nd CPU processor, and by TXD, RXD being set for transmitting-receiving port, BUSY is the output of liquid crystal busy condition, and high level is for busy, and low level is idle.The 2nd CPU processor carries out data read-write operation by the FLASH chip of address bus, data bus, control bus and storer, address bus sends the data address that will read and write, data bus presents the real data in lock address, and control bus is controlled read-write operation and clock signal.Two-port RAM has two cover address buss, data bus, control bus, allow two CPU respectively it to be carried out to data read-write operation, the data that the one CPU processor writes two-port RAM can be read by the 2nd CPU processor, the data that the 2nd CPU processor writes two-port RAM also can be read by a CPU processor, and two CPU carry out data interaction by two-port RAM.Between the 2nd CPU processor and the 3rd CPU processor, by RS485 communication interface, carry out data communication, both are master-slave mode, the 2nd CPU processor is as master control side, the 3rd CPU processor is as being subject to prosecutor, when the 2nd CPU processor requirement the 3rd CPU processor sends data, the 3rd CPU processor just sends the data to the 2nd CPU processor.
Preferred further, the first sample circuit comprises alternating voltage sampling circuit and the direct current voltage-to-ground sample circuit being connected in parallel, alternating voltage sampling circuit connects AD chip after by the first amplifying circuit, direct current voltage-to-ground sample circuit connects AD chip by the second amplifying circuit, AD chip connects a CPU processor, the one CPU processor is connected respectively pilot relay K1 and pilot relay K2 by OT1 port and OT2 port, and pilot relay K1 and pilot relay K2 and alternating voltage sampling circuit and direct current voltage-to-ground sample circuit are arranged in parallel.
Preferred further, alternating voltage sampling circuit comprises capacitor C 1, capacitor C 2, sampling resistor R1 and sampling resistor R2,
The series arm of capacitor C 1 and sampling resistor R1 is connected between positive polarity and ground, the series arm of capacitor C 2 and sampling resistor R2 is connected between voltage negative pole and ground, the common port of capacitor C 1 and sampling resistor R1 is connected the computing operational amplifier A R1 of the first amplifying circuit, capacitor C 2 is connected the operational amplifier A R2 of the first amplifying circuit with the common port of sampling resistor R2, operational amplifier A R1 is connected AD chip with operational amplifier A R2, direct current voltage-to-ground sample circuit comprises balance bridge circuitous resistance R3, balance bridge circuitous resistance R4, sampling resistor R5 and sampling resistor R6, balance bridge circuitous resistance R3 is identical with balance bridge circuit resistance R 4, sampling resistor R5 is identical with sampling resistor R6, the series arm of balance bridge circuitous resistance R3 and sampling resistor R5 is connected between positive polarity and ground, the series arm of balance bridge circuitous resistance R4 and sampling resistor R6 is connected between voltage negative pole and ground, balance bridge circuitous resistance R3 is connected the operational amplifier A R3 of the second amplifying circuit with the common port of sampling resistor R5, balance bridge circuitous resistance R4 is connected the operational amplifier A R4 of the second amplifying circuit with the common port of sampling resistor R6, operational amplifier A R3 is connected AD chip with operational amplifier A R4, AD chip connects a CPU processor, the series arm of pilot relay K1 and detection bridge circuit resistance R 7 is connected between positive polarity and ground, the series arm of pilot relay K2 and detection bridge circuit resistance R 8 is connected between voltage negative pole and ground, pilot relay K1 connects a CPU processor by OT1 port, pilot relay K2 connects a CPU processor by OT2 port.Capacitor C 1 has the logical function exchanging of stopping direct current with capacitor C 2, and resistance R 1 and resistance R 2 are sampling resistor.When fault is scurried in generation interchange, the voltage at resistance R 1 and resistance R 2 two ends can change, voltage is by amplifier amplifier AR1, AR2 is input to AD chip, AD modulus conversion chip is to after its data variation, data are passed to a CPU processor, and a CPU processor is calculated and is exchanged the voltage swing of invading by Fast Fourier Transform (FFT).Resistance R 3, resistance R 4 is balance bridge circuitous resistance, resistance R 5, resistance R 6 forms direct current voltage-to-ground sample circuit, wherein, R3=R4, R5=R6.Wherein resistance R 5, resistance R 6 is direct current both positive and negative polarity voltage-to-ground sampling resistor, resistance R 5, resistance R 6 both end voltage are by the operational amplifier A R3 of discharge circuit, operational amplifier A R4 is input to AD chip, AD chip is given a CPU processor by the digital transfer transforming, and a CPU processor calculates the size of both positive and negative polarity voltage-to-ground by digital signal processing.The one CPU processor is by OT1, two port controlling relay K 1 of OT2, the folding condition of pilot relay K2.When pilot relay K1 closure, pilot relay K2 disconnect, a CPU processor obtains both positive and negative polarity voltage-to-ground value KM1+, KM1-; When pilot relay K1 disconnection, pilot relay K2 closure, a CPU processor obtains both positive and negative polarity voltage-to-ground value KM2+, and KM2-obtains the positive and negative resistance to earth of straight-flow system by mathematical computations.
Preferred further, the second sample circuit comprises the load-carrying branch road that is connected to voltage positive and negative end, on branch road, be provided with sensor, after the operational amplifier A R5 of sensor by the 3rd amplifying circuit, connect the analog to digital conversion circuit AD1 in the 3rd CPU processor.The second sample circuit is mainly responsible for gathering the output voltage of each branch sensor, the operational amplifier A R5 of the output voltage of sensor by discharge circuit is input in the inner integrated AD1 of the 3rd CPU processor, and the 3rd CPU processor is by the data that read AD1 and transform and after calculating, obtain the output voltage values of sensor.Sensor adopts DC leakage current sensor, and when branch road insulate when good, sensor is output as a fixed value, and when branch road defective insulation, the output of sensor can change, and branch road insulation is poorer, and sensor exporting change is larger.
Preferred further, a CPU processor, the 2nd CPU processor adopting TMS320F28335, the 3rd CPU processor adopting C8051F120.Adopt TMS320F28335, high speed digital signal processor, whether data-handling capacity is powerful, can in 20ms, judge to occur to exchange and scurry into fault; Adopting C8051F120, is 51 the strongest single-chip microcomputers of function, can carry out high speed acquisition to sensor output voltage.
The beneficial effect that the utility model has is:
Described Insulation Inspection Device for Direct-Current System can be monitored insulation resistance of DC system, location fault branch, be calculated the interchange input impedance that branch road is scurried in generation interchange when fault is scurried in straight-flow system generation interchange; Do not occur to exchange while scurrying into fault, can monitor insulation resistance of DC system, location insulation reduction branch road, be convenient to field staff the safe operation of straight-flow system is safeguarded, simple in structure, practicality is high.
Accompanying drawing explanation
Fig. 1 is the utility model theory diagram;
Fig. 2 is the utility model liquid crystal display circuit connection layout;
Fig. 3 is the utility model memorizer control circuit connection layout;
Fig. 4 is the utility model the one CPU processor and the 2nd CPU processor connection layout;
Fig. 5 is the utility model the 2nd CPU processor and the 3rd CPU processor connection layout;
Fig. 6 is the utility model the first sample circuit connection layout;
Fig. 7 is the utility model the first sample circuit connection layout;
Fig. 8 is the utility model AC fault simulation drawing;
Wherein, C1-C2, electric capacity; R1, R2, R5, R6, sampling resistor; R3, R4, balance bridge circuitous resistance; R7, R8, detection bridge circuit resistance; Impedance is invaded in R9, interchange; AR1-AR5, operational amplifier; KM1+, KM2+, over against ground voltage; KM1-, KM2-, negative voltage-to-ground; K1-K2, pilot relay.
Embodiment
Below in conjunction with accompanying drawing, embodiment of the present utility model is described further:
As shown in Figures 1 to 5, Insulation Inspection Device for Direct-Current System described in the utility model, comprise a CPU processor, the 2nd CPU processor and the 3rd CPU processor, the one CPU processor connects the 2nd CPU processor by two-port RAM, the 2nd CPU processor connects the 3rd CPU processor by RS458 interface, the one CPU processor connects the first sample circuit and DC voltage input circuit, the 2nd CPU processor connects liquid crystal display circuit and storer, and the 3rd CPU processor connects the second sample circuit and branch sensor input circuit.
Wherein, as shown in Figure 6, the first sample circuit comprises alternating voltage sampling circuit and the direct current voltage-to-ground sample circuit being connected in parallel, alternating voltage sampling circuit connects AD chip after by the first amplifying circuit, direct current voltage-to-ground sample circuit connects AD chip by the second amplifying circuit, AD chip connects a CPU processor, the one CPU processor is connected respectively pilot relay K1 and pilot relay K2 by OT1 port and OT2 port, and pilot relay K1 and pilot relay K2 and alternating voltage sampling circuit and direct current voltage-to-ground sample circuit are arranged in parallel.Alternating voltage sampling circuit comprises capacitor C 1, capacitor C 2, sampling resistor R1 and sampling resistor R2, the series arm of capacitor C 1 and sampling resistor R1 is connected between positive polarity and ground, the series arm of capacitor C 2 and sampling resistor R2 is connected between voltage negative pole and ground, the common port of capacitor C 1 and sampling resistor R1 is connected the computing operational amplifier A R1 of the first amplifying circuit, capacitor C 2 is connected the operational amplifier A R2 of the first amplifying circuit with the common port of sampling resistor R2, operational amplifier A R1 is connected AD chip with operational amplifier A R2, direct current voltage-to-ground sample circuit comprises balance bridge circuitous resistance R3, balance bridge circuitous resistance R4, sampling resistor R5 and sampling resistor R6, balance bridge circuitous resistance R3 is identical with balance bridge circuit resistance R 4, sampling resistor R5 is identical with sampling resistor R6, the series arm of balance bridge circuitous resistance R3 and sampling resistor R5 is connected between positive polarity and ground, the series arm of balance bridge circuitous resistance R4 and sampling resistor R6 is connected between voltage negative pole and ground, balance bridge circuitous resistance R3 is connected the operational amplifier A R3 of the second amplifying circuit with the common port of sampling resistor R5, balance bridge circuitous resistance R4 is connected the operational amplifier A R4 of the second amplifying circuit with the common port of sampling resistor R6, operational amplifier A R3 is connected AD chip with operational amplifier A R4, AD chip connects a CPU processor, the series arm of pilot relay K1 and detection bridge circuit resistance R 7 is connected between positive polarity and ground, the series arm of pilot relay K2 and detection bridge circuit resistance R 8 is connected between voltage negative pole and ground, pilot relay K1 connects a CPU processor by OT1 port, pilot relay K2 connects a CPU processor by OT2 port.
As shown in Figure 7, the second sample circuit comprises the load-carrying branch road that is connected to voltage positive and negative end, is provided with sensor on branch road, connects the analog to digital conversion circuit AD1 in the 3rd CPU processor after the operational amplifier A R5 of sensor by the 3rd amplifying circuit.The one CPU processor, the 2nd CPU processor adopting TMS320F28335, the 3rd CPU processor adopting C8051F120.
DC system insulating monitoring method, its step comprises:
1) after switching on power, the one CPU processor is by the alternating voltage in the first sample circuit Real-time Collection straight-flow system, both positive and negative polarity voltage-to-ground, by a CPU processor inside, carry out accurate Calculation, obtain voltage both positive and negative polarity insulation against ground resistance, then by obtained ac voltage, both positive and negative polarity voltage-to-ground value and both positive and negative polarity insulation against ground resistance value are deposited to two-port RAM;
2) the 2nd CPU processor is by reading two-port RAM, obtain ac voltage, both positive and negative polarity voltage-to-ground value and both positive and negative polarity insulation against ground resistance value, and send it to liquid crystal display circuit, by LCDs, show in real time, and the deposit data that needs are stored is in storer;
3) whether normally the 2nd CPU processor judges straight-flow system operation by the data in two-port RAM, when judging that straight-flow system generation interchange is scurried into or insulation resistance reduces, the 2nd CPU processor is controlled a CPU processor by two-port RAM, and pilot relay K1 is closed, pilot relay K2 disconnects, read now both positive and negative polarity voltage-to-ground KM1+ and KM1-, simultaneously, the 2nd CPU processor is controlled the 3rd CPU processor by RS485 interface and is sent the output data I 1 of each branch sensor of the second sample circuit collection to it, then the 2nd CPU processor control the one CPU processor disconnects pilot relay K1, pilot relay K2 is closed, read now both positive and negative polarity voltage-to-ground KM2+ and KM2-, the 2nd CPU processor is again controlled the 3rd CPU processor by RS485 interface and is sent the output data I 2 of each branch sensor of the second sample circuit collection to it, finally, pass through KM1+, KM1-, KM2+, KM2-, I1 and I2 obtain the insulating resistance value of each branch road.
As shown in Figure 8, the positive pole that passes through branch road 1 when the live wire of AC power by R9 is scurried into straight-flow system.Because the internal resistance of AC power is very little, negligible; The insulation resistance that device can calculate system is 40K, and the sensor of branch road 1 is output as when branch road 1 is anodal passes through the direct ground connection of 40K resistance, and the leakage current value of branch road 1 transforms the magnitude of voltage obtaining in proportion.It is 40K that impedance is scurried in the 2nd CPU processor can obtain branch road 1 interchange by calculating.
The utility model can be monitored insulation resistance of DC system, location fault branch, be calculated the interchange input impedance that branch road is scurried in generation interchange when fault is scurried in straight-flow system generation interchange, do not occur to exchange while scurrying into fault, can monitor insulation resistance of DC system, location insulation reduces branch road.
Claims (5)
1. an Insulation Inspection Device for Direct-Current System, comprise a CPU processor, the 2nd CPU processor and the 3rd CPU processor, it is characterized in that: a CPU processor connects the 2nd CPU processor by two-port RAM, the 2nd CPU processor connects the 3rd CPU processor by RS458 interface, the one CPU processor connects the first sample circuit and DC voltage input circuit, the 2nd CPU processor connects liquid crystal display circuit and storer, and the 3rd CPU processor connects the second sample circuit and branch sensor input circuit.
2. Insulation Inspection Device for Direct-Current System according to claim 1, it is characterized in that: the first described sample circuit comprises alternating voltage sampling circuit and the direct current voltage-to-ground sample circuit being connected in parallel, alternating voltage sampling circuit connects AD chip after by the first amplifying circuit, direct current voltage-to-ground sample circuit connects AD chip by the second amplifying circuit, AD chip connects a CPU processor, the one CPU processor is connected respectively pilot relay K1 and pilot relay K2 by OT1 port and OT2 port, pilot relay K1 and pilot relay K2 and alternating voltage sampling circuit and direct current voltage-to-ground sample circuit are arranged in parallel.
3. Insulation Inspection Device for Direct-Current System according to claim 2, it is characterized in that: described alternating voltage sampling circuit comprises capacitor C 1, capacitor C 2, sampling resistor R1 and sampling resistor R2, the series arm of capacitor C 1 and sampling resistor R1 is connected between positive polarity and ground, the series arm of capacitor C 2 and sampling resistor R2 is connected between voltage negative pole and ground, capacitor C 1 is connected the operational amplifier A R1 of the first amplifying circuit with the common port of sampling resistor R1, capacitor C 2 is connected the operational amplifier A R2 of the first amplifying circuit with the common port of sampling resistor R2, operational amplifier A R1 is connected AD chip with operational amplifier A R2, direct current voltage-to-ground sample circuit comprises balance bridge circuitous resistance R3, balance bridge circuitous resistance R4, sampling resistor R5 and sampling resistor R6, balance bridge circuitous resistance R3 is identical with balance bridge circuit resistance R 4, sampling resistor R5 is identical with sampling resistor R6, the series arm of balance bridge circuitous resistance R3 and sampling resistor R5 is connected between positive polarity and ground, the series arm of balance bridge circuitous resistance R4 and sampling resistor R6 is connected between voltage negative pole and ground, balance bridge circuitous resistance R3 is connected the operational amplifier A R3 of the second amplifying circuit with the common port of sampling resistor R5, balance bridge circuitous resistance R4 is connected the operational amplifier A R4 of the second amplifying circuit with the common port of sampling resistor R6, operational amplifier A R3 is connected AD chip with operational amplifier A R4, AD chip connects a CPU processor, the series arm of pilot relay K1 and detection bridge circuit resistance R 7 is connected between positive polarity and ground, the series arm of pilot relay K2 and detection bridge circuit resistance R 8 is connected between voltage negative pole and ground, pilot relay K1 connects a CPU processor by OT1 port, pilot relay K2 connects a CPU processor by OT2 port.
4. Insulation Inspection Device for Direct-Current System according to claim 1, it is characterized in that: the second described sample circuit comprises the load-carrying branch road that is connected to voltage positive and negative end, on branch road, be provided with sensor, after the operational amplifier A R5 of sensor by the 3rd amplifying circuit, connect the analog to digital conversion circuit AD1 in the 3rd CPU processor.
5. Insulation Inspection Device for Direct-Current System according to claim 1, is characterized in that: a described CPU processor, the 2nd CPU processor adopting TMS320F28335, the 3rd CPU processor adopting C8051F120.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320605708.0U CN203455412U (en) | 2013-09-27 | 2013-09-27 | DC system insulation monitoring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320605708.0U CN203455412U (en) | 2013-09-27 | 2013-09-27 | DC system insulation monitoring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203455412U true CN203455412U (en) | 2014-02-26 |
Family
ID=50135278
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320605708.0U Withdrawn - After Issue CN203455412U (en) | 2013-09-27 | 2013-09-27 | DC system insulation monitoring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203455412U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103472309A (en) * | 2013-09-27 | 2013-12-25 | 山东智洋电气有限公司 | Insulation monitoring device and method for DC system |
| CN106405354A (en) * | 2016-11-24 | 2017-02-15 | 北京共元科技有限公司 | Direct current insulation monitoring circuit and method |
-
2013
- 2013-09-27 CN CN201320605708.0U patent/CN203455412U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103472309A (en) * | 2013-09-27 | 2013-12-25 | 山东智洋电气有限公司 | Insulation monitoring device and method for DC system |
| CN103472309B (en) * | 2013-09-27 | 2015-10-14 | 山东智洋电气有限公司 | Insulation Inspection Device for Direct-Current System and method |
| CN106405354A (en) * | 2016-11-24 | 2017-02-15 | 北京共元科技有限公司 | Direct current insulation monitoring circuit and method |
| CN106405354B (en) * | 2016-11-24 | 2024-01-16 | 北京共元科技有限公司 | DC insulation monitoring circuit and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103472309B (en) | Insulation Inspection Device for Direct-Current System and method | |
| CN203673023U (en) | Terminal apparatus for detecting insulation condition of direct current system | |
| CN202886514U (en) | Direct current (DC) system grounding detector | |
| CN102998511B (en) | A kind of lightning arrester discharge current monitoring device | |
| CN106291084B (en) | A kind of power transformer near region short circuit monitoring method | |
| CN203965613U (en) | A kind of emulation test system of earth-fault indicator performance | |
| CN203606424U (en) | On-line monitoring device for grounding current of transformer core | |
| CN207335915U (en) | A kind of cable monitoring system | |
| CN201607499U (en) | Generator-transformer composite monitoring and recording device | |
| CN106786467A (en) | Fault warning and device for preventing unwanted operation are scurried into one kind exchange | |
| CN105371742A (en) | Bushing tap pulse signal injection method-based transformer winding deformation detection device and method | |
| CN203455412U (en) | DC system insulation monitoring device | |
| CN205844461U (en) | A kind of inside switch cabinet high pressure equipment partial discharge monitoring system | |
| CN203164360U (en) | Transformer device insulation online monitoring system | |
| CN203069713U (en) | Alternating-current-into-direct-current monitoring device | |
| CN203310903U (en) | Transformer iron core earth current online monitor | |
| CN207424224U (en) | A kind of device for possessing on-line monitoring exchange and scurrying into DC power system function | |
| CN104391145B (en) | Online low-voltage leakage power stealing testing arrangement and its implementation | |
| CN103760411A (en) | Direct-current bus voltage wave-recording device | |
| CN205176699U (en) | Distribution data acquisition device | |
| CN205067646U (en) | Direct current system insulation monitoring and warning device | |
| CN209215554U (en) | A kind of device for scurrying into monitoring function with accumulator monitoring and exchange | |
| CN203848796U (en) | On-line monitoring device of power distribution network transformer low-voltage winding deformation | |
| CN202548319U (en) | Test device of power consumption of electric energy meter | |
| CN203350385U (en) | Direct current system parasitic circuit on-line detection apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20140226 Effective date of abandoning: 20151014 |
|
| C25 | Abandonment of patent right or utility model to avoid double patenting |