A kind of grounding transformer
The utility model belongs to and relates to a kind of grounding transformer.
Generation current machine is all by high resistance grounding, can restricted grounding current, suitably can also reduce grounding surge.Principle is that grounding transformer is changed by amplifying by the secondary side small resistor of secondary, is presented on primary side high impedance, thus effectively limits Capacitive Flow.But when ground connection occurs generator, grounding transformer can only limit neutral point current, and the compensation inductance current provided is very little, easily causes generator failure.
Utility model content
The purpose of this utility model is to provide a kind of grounding transformer, solves the problem that compensation inductance current that current grounding transformer provides is very little.
To achieve these goals, the technical solution adopted in the utility model is as follows:
A kind of grounding transformer, comprise iron core, on described iron core, side is wound with main coil, and opposite side is wound with secondary coil; Described main coil one end is connected with generator neutral point by isolation switch, other end ground connection; Rheostat R is provided with between two outputs of described secondary coil, and one of them output head grounding; The inductance L in parallel with rheostat R is also provided with between two outputs of described secondary coil.
Further, described main coil and secondary coil are equipped with an induction coil.
The utility model compared with prior art, has the following advantages and beneficial effect:
When the capacitance current of generator is larger, greatly to a certain extent, earth point electric arc can not automatic distinguishing, easily causes electricity generator stator core to damage for earth current.After using grounding transformer of the present utility model, owing to being provided with inductance, can produce inductive electric current when generator generation single-phase earthing, the capacitance current of compensation of ground point and make earth point electric arc automatic distinguishing, thus it is damaged effectively to avoid electricity generator stator core.
Accompanying drawing explanation
Fig. 1 is circuit theory diagrams of the present utility model.
Below in conjunction with drawings and Examples, the utility model is described in further detail, and execution mode of the present utility model includes but not limited to the following example.
As shown in Figure 1, a kind of grounding transformer, comprises iron core, and on described iron core, side is wound with main coil, and opposite side is wound with secondary coil; Described main coil one end is connected with generator neutral point by isolation switch, other end ground connection; Rheostat R is provided with between two outputs of described secondary coil, and one of them output head grounding; The inductance L in parallel with rheostat R is also provided with between two outputs of described secondary coil.By arranging inductance L on secondary coil, can afford redress when ground connection occurs generator inductance current.
Particularly, described main coil and secondary coil are equipped with an induction coil.Current electric current can be responded to by induction coil, facilitate operated by personnel.
The utility model principle illustrates:
Generator is when normally running, and it is high resistance that grounding transformer secondary side (secondary coil) resistance converts primary side (main coil), makes generator neutral point by high resistance grounding, balancing generator outlet three-phase voltage;
During generator generation earth fault, grounding transformer secondary side inductance is converted primary side and is formed certain inductance compensation electric current, the capacity current that compensated dynamo neutrality flows through, and reduces the size of electric current thus protects primary equipment.
According to above-described embodiment, just the utility model can be realized well.What deserves to be explained is; under prerequisite based on said structure design; for solving same technical problem; even if some making on the utility model are without substantial change or polishing; the essence of the technical scheme adopted is still the same with the utility model, therefore it also should in protection range of the present utility model.