CN2446703Y - Four-branch combined overvoltage protector - Google Patents

Abstract

The utility model relates to an overvoltage protector, a novel four branch road combination formula overvoltage protector promptly, its characteristics lie in that the protection device in the protection branch road of connecting ground wire G only comprises zinc oxide nonlinear resistor in the four protection branch roads, and the direct current 1mA reference voltage value of the zinc oxide nonlinear resistor in the protection branch road of connecting ground wire G is 0 ~ 1 times of the direct current 1mA reference voltage value of the zinc oxide nonlinear resistor in other three protection branch roads, the parameter of connecting the protection device in three protection branch roads of being protected equipment's A phase line, B phase line and C phase line is the same. The utility model discloses can eliminate stray capacitance effectively and to protector return circuit voltage distribution's influence, make the protector have stable power frequency discharge voltage value, make the protector have longer life, moreover, can also simplify production technology, reduction in production cost is low, has high practicality and uses widely value.

Description

Novel four branch combinations formula overvoltage protectors

The utility model relates to over-pressure safety device.More particularly, be a kind of over-pressure safety device that is used for high-voltage electrical equipment.

Because high-voltage electrical equipment, as motor, transformer and bus etc., not only insulation relatively has certain limit, and a little less than phase insulation also is highly brittle; Therefore; for the alternate superpotential protection multiple that makes high-voltage electrical equipment equates with equipment superpotential protection multiple relatively or close; avoid atmospheric over-voltage or switching overvoltage to cause the damage or the puncture of equipment phase insulation; in the prior art, generally adopt simple Modular Three-Phase Overvoltage Protector.This protector is and penetrates shape and connect four protection branch roads from mid point O is set, and the other end of four protection branch roads connects A phase line, B phase line, C phase line and the ground wire G of protected equipment respectively; Protection device in four protection branch roads of this protector is composed in series by discharging gap and znr.But, in actual the use, because under the effect of power-frequency voltage and surge voltage, electric current before the protector action is very little, again since the capacitance of discharging gap much smaller than the capacitance of znr, therefore, the voltage between alternate or phase ground mainly is distributed on the discharging gap according to the relative size of the capacitance of each discharging gap; And surrounding environment all can greatly change the size of discharging gap capacitance such as the stray capacitance that is produced between the earth or aerial condutor and the protection device, thereby the voltage distribution in the loop is changed, and then changes the power-frequency sparkover voltage value of protector; As seen, though this protector has solved the protection problem of the phase insulation of equipment to a certain extent,, because the power-frequency sparkover voltage value instability of self, as easy as rolling off a log generation malfunction of this protector or tripping cause bigger harm for whole electric power system.

In order to protect the phase insulation of high-voltage electrical equipment, in the prior art, also can adopt four branch combinations formula overvoltage protectors.Different with Modular Three-Phase Overvoltage Protector, the protection device in described four the protection branch roads of this protector is composed in series by znr and the discharging gap that carries parallel resistance, or only is made up of znr.There is the defective that production cost is higher, technology is loaded down with trivial details in preceding a kind of structure of this protector; Then there is the too high defective of chargeability of znr in back a kind of structure of this protector, and this defective very easily causes the useful life of protector self too short.

The purpose of this utility model is to avoid above-mentioned deficiency of the prior art; a kind of power-frequency sparkover voltage value stabilization is provided; production cost is low, the novel four branch combinations formula overvoltage protectors of the simple joint of technology and long service life, to guarantee the safe operation of power equipment.

The purpose of this utility model is achieved through the following technical solutions:

The utility model has four protection branch roads; one end of described four protection branch roads is connected in 1 O; the other end of described four protection branch roads connects A phase line, B phase line, C phase line and the ground wire G of protected equipment respectively, wherein connects protection device in the protection branch road of A phase line, B phase line and C phase line of protected equipment by znr F _R1, F _R2And F _R3Respectively with carry parallel resistance R ₁, R ₂And R ₃Discharging gap J ₁, J ₂And J ₃Be composed in series; Design feature of the present utility model is: the protection device in the protection branch road of described connection ground wire G is only by znr F _R4Form the znr F in the protection branch road of connection ground wire G _R4Direct current 1mA reference voltage level be znr F in other three protection branch roads _R1, F _R2And F _R30～1 times of direct current 1mA reference voltage level, the parameter of the protection device in three protection branch roads of the A phase line of the protected equipment of described connection, B phase line and C phase line is identical.

The utility model can be eliminated stray capacitance effectively to the influence that the protector loop voltage distributes, and makes protector have stable power-frequency sparkover voltage value; Compare with four branch combinations formula overvoltage protectors, the utility model can not only be simplified production technology, reduces production costs; And, can also reduce the chargeability of znr, make protector have longer useful life, have high practicality and popularizing value.

Accompanying drawing 1 is a structural representation of the present utility model.

By the following examples, in conjunction with the accompanying drawings 1, the utility model is further described.

Embodiment:

Referring to accompanying drawing 1; the utility model has four protection branch roads; one end of described four protection branch roads is connected in 1 O; the other end of described four protection branch roads connects A phase line, B phase line, C phase line and the ground wire G of protected equipment respectively, wherein connects protection device in the protection branch road of A phase line, B phase line and C phase line of protected equipment by znr F _R1, F _R2And F _R3Respectively with carry parallel resistance R ₁, R ₂And R ₃Discharging gap J ₁, J ₂And J ₃Be composed in series; Protection device in four protection branch roads described in the utility model in the protection branch road of connection ground wire G is only by znr F _R4Form the znr F in the protection branch road of connection ground wire G _R4Direct current 1mA reference voltage level be znr F in other three protection branch roads _R1, F _R2And F _R30～1 times of direct current 1mA reference voltage level, the parameter of the protection device in three protection branch roads of the A phase line of the protected equipment of described connection, B phase line and C phase line is identical.With the protection device J in the protection branch road of connection ground wire G in the former protector ₄And parallel resistance R ₄The purpose of removing is to simplify production technology, reduces production costs; And set up gap J ₁, J ₂And J ₃Purpose be to reduce the chargeability of znr, make protector have longer useful life.

Assembling of the present utility model and using method are as follows:

1,, required components and parts have at first been chosen according to designing requirement;

2, according to the structure chart of design, use electrode and other auxiliary member, with protection device link cost utility model patent device, promptly novel four branch combinations formula overvoltage protectors.

3, when system power supply is cut off, the utility model Patent equipment and protected equipment are connected in parallel according to installation diagram.After the system restoration operation, the utility model Patent equipment just can guarantee the safe operation of protected equipment.

Claims (1)

1, novel four branch combinations formula overvoltage protectors; have four protection branch roads; one end of described four protection branch roads is connected in 1 O; the other end of described four protection branch roads connects A phase line, B phase line, C phase line and the ground wire G of protected equipment respectively, wherein connects protection device in the protection branch road of A phase line, B phase line and C phase line of protected equipment by znr F _R1, F _R2And F _R3Respectively with engrave band parallel resistance R ₁, R ₂And R ₃Discharging gap J ₁, J ₂And J ₃Be composed in series, it is characterized in that: the protection device in described four protection branch roads in the protection branch road of connection ground wire G is only by znr F _R4Form the znr F in the protection branch road of connection ground wire G _R4Direct current 1mA reference voltage level be znr F in other three protection branch roads _R1, F _R2And F _R30～1 times of direct current 1mA reference voltage level, the parameter of the protection device in three protection branch roads of the A phase line of the protected equipment of described connection, B phase line and C phase line is identical.

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