A kind of low voltage three-phase line fault generator
Technical field
The utility model relates to a kind of low voltage three-phase line fault generator.
Background technology
Electrical network dynamic similation is the important means of analyzing electric system feature, test relay protection and secondary device.Meeting under the condition of electric system criterion of similarity, press the principle of Scaling capacity, adopt low-voltage equipment (being generally 100-1000V) simulated high-pressure grid equipment (10kV and more than), build small grids dynamic simulator system, can carry out in laboratory the research of electrical network dynamic perfromance.Line short and ground connection are electrical network most common failures, are also the important research contents of carrying out electrical network dynamic similation.Line short and earth fault are mainly divided into 4 kinds of three-phase shortcircuit, line to line fault, line to line fault ground connection, single-line to ground faults etc.The instantaneous increase of fault current during due to line short or ground connection, can cause that conductor temperature raises rapidly, device damage; The serious accidents such as the electric arc that short circuit produces, spark can initiation fires, blast, electricity wound.But while carrying out electrical network dynamic similation, often need to carry out the simulation of short circuit and earth fault, therefore, the design and use of line short and earth fault generator are safely the difficult points of electrical network dynamic similation.
Utility model content
The utility model is in order to address the above problem, a kind of low voltage three-phase line fault generator has been proposed, this device generates short circuit and earth fault for three-phase low-voltage electrical network dynamic simulator system, limited the size of fault current, by needing the position of simulated failure in time control isolating switch access electrical network dynamic simulator system, and pre-configured fault occurs constantly and trouble duration.
To achieve these goals, the utility model adopts following technical scheme:
A kind of low voltage three-phase line fault generator, comprise three-phase time control isolating switch, three-phase resistance load box, short circuit combined switch and ground connection combined switch, wherein, three-phase time control isolating switch comprises three time control isolating switchs, three-phase resistance load box comprises three resistor load boxes, the input end of each time control isolating switch connects respectively the inlet wire of three-phase line, output terminal connects a resistor load box, ground connection after a grounding switch of each resistor load box connection, short circuit combined switch comprises three short circuiting switches, each short circuiting switch is connected to the output terminal of two different resistor load boxes.
Described three-phase time control isolating switch connects the inlet wire of the three-phase line of fault simulation point on electrical network dynamic simulator system, and the closing moment of time control isolating switch and closure time can arrange.
The scope that arranges of described trouble duration is 0.1-100 seconds.
Described three-phase time control isolating switch has microcomputer type controller, band LCDs.
Described three-phase resistance load box is connected in major loop, comprises the wire resistor that several are in parallel, and every phase resistance is 1.0 Ω, rated power 20kW, adopts wind-cooling heat dissipating, and specified temperature rise is less than 375 ℃.
Principle of work of the present utility model is: first three-phase time control isolating switch is in a minute position, and the microcomputer type controller of timing is enabled; Again according to the fault that will simulate, deciliter position of each switch in short circuit combined switch and ground connection combined switch is set, for example, while simulating line to line fault earth fault, in short circuit can being combined, between A, B, in switch closure, ground connection combined switch, A phase grounding switch is closed; Then by the microcomputerized controller of three-phase time control isolating switch, be set closing moment and the duration of three-phase time control isolating switch; The timing of finally enabling three-phase time control isolating switch microcomputerized controller, waits the generation of institute's simulated failure.
The beneficial effects of the utility model are:
(1) can simulate the various short circuits of low voltage three-phase circuit and earth fault, there is the function of safety protection such as fault current current limliting and control fault-time, for the electrical network dynamic simulator system that adopts low-voltage equipment to build in laboratory provides a kind of simple, safe and reliable failure simulation device;
(2), by the combination of internal switch, the fault types such as phase short circuit, line to line fault, line to line fault ground connection, single-line to ground fault can be set flexibly; The high-power resistance load of connecting in loop, has limited the size of fault current; By needing the position of simulated failure in time control isolating switch access electrical network dynamic simulator system, and pre-configured fault occurs constantly and trouble duration.
Accompanying drawing explanation
Fig. 1 is that system of the present utility model forms structural representation;
Wherein, 1. three-phase time control isolating switch, 2. three-phase resistance load box, 3. short circuit combined switch, 3-1,3-2,3-3. short circuiting switch, 4. ground connection combined switch, 4-1,4-2,4-3. grounding switch.
Embodiment:
Below in conjunction with accompanying drawing and embodiment, the utility model is described in further detail.
As shown in Figure 1, by the following technical solutions, low voltage three-phase line fault generator is comprised of three-phase time control isolating switch 1, three-phase resistance load box 2, short circuit combined switch 3, ground connection combined switch 4 the utility model.Described three-phase time control isolating switch is connected to the fault simulation position of circuit, and specified uninterrupted electric current is greater than 630A; Have microcomputer type controller, band LCDs, can arrange fault and occur constantly and trouble duration.The scope that arranges of trouble duration is 0.1-100 seconds, and simulation can be set to 2 seconds during short trouble conventionally, causes device damage when avoiding the tripping of higher level's short-circuit protection.Described three-phase resistance load box is connected in major loop, and each phase resistance is formed in parallel by wire resistor, and every phase resistance is 1.0 Ω, rated power 20kW, adopts wind-cooling heat dissipating, and specified temperature rise is less than 375 ℃.Described short circuit combined switch is comprised of 3 switches, be connected to respectively AB phase, BC phase and CA mutually between, each switch can manually be controlled deciliter.Described ground connection combined switch is comprised of 3 switches, and by A, B, C three-phase ground connection respectively, each switch can manually be controlled deciliter.
The method of work of low voltage three-phase line fault generator: first three-phase time control isolating switch is in a minute position, and the microcomputer type controller of timing is enabled; Again according to the fault that will simulate, deciliter position of each switch in short circuit combined switch and ground connection combined switch is set, for example, while simulating line to line fault earth fault, in short circuit can being combined, between A, B, in switch closure, ground connection combined switch, A phase grounding switch is closed; Then by the microcomputerized controller of three-phase time control isolating switch, be set closing moment and the duration of three-phase time control isolating switch; The timing of finally enabling three-phase time control isolating switch microcomputerized controller, waits the generation of institute's simulated failure.
La, Lb, Lc represent the inlet wire of the three-phase line of fault simulation point on electrical network dynamic simulator system, the end of incoming cables of access three-phase time control isolating switch 1, and 3 phase resistance loops of three-phase resistance load box 2 are connected respectively to the leading-out terminal of three-phase time control isolating switch 1.Short circuit combined switch 3 comprises 3 hand switch 3-1,3-2 and 3-3, switch 3-1 is connected between A, B phase, be used for simulating A, B phase fault, switch 3-2 is connected between B, C phase, be used for simulating B, C phase fault, switch 3-3 is connected between A, C phase, for simulating A, C phase fault.Ground connection combined switch 4 comprises 3 hand switch 4-1,4-2 and 4-3, and switch 4-1 is connected between A phase and ground, and switch 4-2 is connected between B phase and ground, and switch 4-3 is connected between C phase and ground, simulates respectively the earth fault of 3 phases.Deciliter position of deciliter position of 3 switches of short circuit combined switch and 3 switches of ground connection combined switch is combined, can simulate any short circuit of three-phase line and earth fault.While carrying out fault simulation, first according to simulated fault, deciliter position of each switch in short circuit combined switch and ground connection combined switch is manually set, closing moment and the duration of time control isolating switch are set again, enable after the microcomputerized controller of time control isolating switch, can regularly generate set fault.
Although above-mentioned, by reference to the accompanying drawings embodiment of the present utility model is described; but the not restriction to the utility model protection domain; one of ordinary skill in the art should be understood that; on the basis of the technical solution of the utility model, those skilled in the art do not need to pay various modifications that creative work can make or distortion still in protection domain of the present utility model.