Summary of the invention
In view of above-mentioned, task of the present utility model is to propose a kind of ground connection, short trouble indicator, and it can indicate phase fault can indicate singlephase earth fault again.
Task of the present utility model realizes by following scheme: a kind of ground connection and short circuit line fault detector comprise:
Microprocessor receives the signal that following each circuit is sent, and produces the drive signal of control indicating device;
Sudden change amount signal circuit, the unexpected variation of detection line electric current, its output connects the data input pin of microprocessor;
The current signal circuit, the having or not of detection line electric current, its output connects the data input pin of microprocessor;
Voltage signal circuit, the size variation of detection line voltage, its output connects the simulated data input end of microprocessor;
The harmonic signal circuit, the size variation of harmonic current in the detection line, its output connects the simulated data input end of microprocessor;
Indicating device is used for indication fault, and its input connects the output of microprocessor; Power supply is for above circuit provides power supply.
In implementing measure of the present utility model:
Described sudden change amount signal circuit is connected in series successively by rectification circuit, stabilivolt, switching tube and constitutes, and the output of its switching tube connects a data input pin of microprocessor.
Described current signal circuit is made of half-wave rectifying circuit and switching tube serial connection, and the output of its switching tube connects a data input pin of microprocessor.
Described voltage signal circuit is a current rectifying and wave filtering circuit, and its output connects the first simulated data input end of microprocessor.
Described harmonic signal circuit is made of Hi-pass filter and current rectifying and wave filtering circuit serial connection, and the output of current rectifying and wave filtering circuit connects the second simulated data input end of microprocessor.
Described indicating device comprises driving circuit and electromagnetic deflection indicating device, and wherein: driving circuit is made of four electronic switches that connect into electric bridge and magnetizing coil; The electromagnetic deflection indicating device by the dome shape body that holds magnetizing coil, the quiet tube of the dome shape that is connected with body, be bearing in the moving tube of dome shape between body and the quiet tube and hold above-mentioned body, quiet tube, moving and the shell of circuit constitutes, moving tube is towards the fixing permanent magnetic sheet of an end of body, moving tube is coated with warning color and perforate on the cover end face of quiet tube, the cover of quiet tube backs down window, its cover top inner face fixedly stretches into the pawl that stops in the moving tube cover apical pore, and a side on corresponding quiet tube cover top is transparent on the shell.
Described indicating device also can be indicator light circuit or sound circuit.
The indication phase fault that the utility model energy is correct, can correctly judge indication metallicity, nonmetal character and permanent, instantaneity singlephase earth fault, make the electric system track walker can find the trouble spot rapidly, restore electricity as early as possible, thereby can improve the power supply reliability of electric system greatly, can create bigger social benefit and economic benefit.
Embodiment
According to the electric system theory, when small current neutral grounding system generation singlephase earth fault, following situation can take place:
A. the fault phase-to-ground voltage descends, and non-fault phase-to-ground voltage raises, and the system zero sequence voltage raises, and its numerical value is less than or equal to system's phase voltage;
B. ground path ground connection phase, before the trouble spot, the capacitance current maximum that flows through on the circuit is all the outlet capacitance current sums mutually of non-ground connection on the same bus.
This theory is mainly as ground connection, the theoretical foundation of short trouble indicator when judging singlephase earth fault.
The criterion that ground connection, short trouble indicator are adopted:
1. singlephase earth fault criterion: voltage descends; And triple harmonic current increases.
2. phase fault criterion: the current break discharge amplitude is greater than setting value; The mutation current retention time is in range of set value; And decompression, defluidization behind the current break.
See also Fig. 1, the utility model is a kind of ground connection and short circuit line fault detector, and it comprises:
Microprocessor 11 (the optional 97C2051 of model) is used to receive the signal that following each circuit is sent, and produces the drive signal of control indicating device 17; Sudden change amount signal circuit 12 is used for the unexpected variation of detection line electric current, and its output connects the data input pin of microprocessor 11; Current signal circuit 13 is used for having or not of detection line electric current, and its output connects the data input pin of microprocessor 11; Voltage signal circuit 14 is used for the size variation of detection line voltage, and its output connects the simulated data input end of microprocessor 11; Harmonic signal circuit 15 is used for the size variation of detection line harmonic current, and its output connects the simulated data input end of microprocessor 11; Indicating device 17 is used for indication fault, and its input connects the output of microprocessor 11; Power supply 16 is for above circuit provides power supply.
See also Fig. 2.Sudden change amount signal circuit is connected in series successively by rectification circuit D1-D4, stabilivolt DW1-DW2, switching tube N1 and constitutes, and the anode of DW1 connects the negative electrode of DW2, and through C1 ground connection, the output of N1 meets the input end P0.1 of microprocessor.Its function is to produce a signal when the power circuit jump-value of current reaches setting value.The current signal of obtaining through card line mechanism and mutual inductor from the power circuit becomes a direct current signal after the D1-D4 full-wave rectification.When the unexpected change of electric current on the circuit reached certain value greatly, DW1-DW2 was breakdown, the N1 conducting, and its output terminal OUT exports a undersuing to microprocessor.
See also Fig. 3.The current signal circuit is made of half-wave rectifying circuit C2 and D2, switching tube N2 serial connection, and the output of N2 meets the data input pin P0.2 of microprocessor.Its function is when on the power circuit electric current being arranged, and produces continuous impulse, is used for whether electric current is arranged on the decision circuitry.When current signal is positive half cycle, the N2 conducting; During the current signal negative half period, N2 ends.When in the power circuit electric current being arranged, N2 exports continuous impulse, and when not having electric power, N2 is output as high level.
See also Fig. 4.The current rectifying and wave filtering circuit of voltage signal circuit for being made of D3-D6, R3, C3, its output meets the simulated data input end AD0 of microprocessor.Its function mainly is voltage signal and the variation thereof that obtains on the power circuit.Voltage on the power circuit is sent into microprocessor and is carried out data acquisition and processing (DAP) behind rectifying and wave-filtering.
Because the content of third harmonic is less in the power circuit electric current, need to adopt filtering technique, the triple harmonic current signal is leached from the power circuit current signal.See also Fig. 5.The harmonic signal circuit is made of Hi-pass filter and current rectifying and wave filtering circuit serial connection.R4, RW1, C4, C5, R5 and operational amplifier IC1 form two rank Hi-pass filter, and D7, R6, C6 form current rectifying and wave filtering circuit, and the output of current rectifying and wave filtering circuit meets the simulated data input end AD1 of microprocessor.
When this wave filter of current signal process, wave filter leaches harmonic signal wherein, simultaneously fundamental signal is wherein significantly decayed, and the signal of IC1 output is sent into microprocessor and carried out data acquisition and processing (DAP) behind rectifying and wave-filtering.
Whether the signal that microprocessor is sent into above-mentioned each circuit carries out analysis-by-synthesis, make according to singlephase earth fault criterion and phase fault criterion and breaking down on the circuit and the whether judgement of this indication fault of indicator.If should move or involution, then send the corresponding driving signal and give indicating device.
Indicating device comprises driving circuit and electromagnetic deflection indicating device, wherein:
See also Fig. 6.Driving circuit is made of four electronic switch BT1, the BT2, N3, N4 and the magnetizing coil L that connect into electric bridge, and the control end K1-K4 of four electronic switches meets the data terminal P1.1-P1.4 from microprocessor respectively.Make when microprocessor and to have broken down on the circuit or during trouble-free judgement, send a high impulse then for respectively K1 and K4 or K2 and K3, corresponding one tunnel two electronic switches in the electric bridge are connected, make and flow through a pulse current forward or backwards among the magnetizing coil L.
See also 7-9.The electromagnetic deflection indicating device by the dome shape body 2 that holds magnetizing coil, the quiet tube 3 of the dome shape that is connected with body 2, with bearing part 8 and 5 be bearing in the moving tube 4 of dome shape between body 2 and the quiet tube 3 and hold above-mentioned body, quiet tube, moving shell 1 constitutes.Wherein: magnetizing coil is contained in the cover of body 2, and extend for a pair of slot 9 that foregoing circuit is used is installed the bottom of body 2; Moving tube 4 is fixed permanent magnetic sheet 6 in an end rotating shaft 7 of body 2, moving tube 4 is coated with warning color (redness) and has three holes 10 of wrong 120 degree mutually on the cover end face of quiet tube 3; The cover of quiet tube 3 backs down three windows 11 of wrong 120 degree mutually, and its cover top inner face fixedly stretches into and stops pawl 12 in the moving tube cover apical pore, and the side that corresponding quiet tube 3 covers push up on the shell 1 is transparent.
Make when microprocessor and to have broken down on the circuit when judging, the two electronic switches connection that microprocessor just will corresponding a tunnel makes and flows through a direct impulse electric current among the magnetizing coil L.This electric current with magnetizing coil L wear axle be magnetized to an end be the N utmost point in addition end be the S utmost point, this acts on the permanent magnetic sheet 6 that moves on the tube 4 to magnetic pole, make tube 4 deflections, until its hole 10 run into quiet tube 3 stop pawl 12 till, warning color zone of its cover end face just goes to the position of the window 11 of corresponding quiet tube 3.Can be observed this warning color by transparent outer cover and expose window.This moment, indicating device was in indicating fault status.
When microprocessor was made on the circuit trouble-free judgement, microprocessor was just connected two electronic switches on another road, makes and flows through a reverse impulse electric current among the magnetizing coil L.At this moment move tube 4 with reverse deflection, warning color zone of its cover end face is by the covering of the cover of quiet tube 3 top.Can't see this warning color by transparent outer cover and expose window.This moment, indicating device was in reset mode.
The advantage of this indicating device is: only need a pulse signal to drive, the position of moving tube does not need to keep with other energy.
Above-mentioned power supply can be made of rectification filtering power and backup battery, and rectification filtering power is obtained energy from power circuit, for other circuit working.The energy shortage of obtaining from power circuit at rectification filtering power then provides energy by backup battery to circuit during for other circuit operate as normal.
In other embodiment of the present utility model, indicating device can also be indicator light circuit or sound circuit, makes when microprocessor and having broken down on the circuit when judging, microprocessor is just sent signal, drives that indicator light circuit is lighted or sound circuit sends the sound.Because indicator light circuit or sound circuit are known technology, so do not repeat them here.