CN203553925U - Instantaneous overvoltage protection device for high energy consumption monitoring system - Google Patents

Abstract

The utility model relates to an instantaneous overvoltage protection device for a high energy consumption monitoring system. The protection device is composed of a precision transformer protection mechanism and an acquisition board card protection mechanism, wherein the precision transformer protection mechanism comprises a high-voltage signal input terminal, a 3W51K consumptive resistor, a 1.5KE250 bidirectional transient voltage suppressor TVS, a high-voltage signal output terminal and a precision transformer, which are sequentially connected with electrodes of a smelting electric-arc furnace; and the acquisition board card protection mechanism comprises a low-voltage signal input terminal, a 1W51K consumptive resistor, an SMBJ12CA bidirectional transient voltage suppressor TVS, a low-voltage signal output terminal and an NI data acquisition board card, which are sequentially connected with a voltage transformer. The instantaneous overvoltage protection device can suppress high and low voltage transmission signals of an electric-arc furnace smelting system within a certain voltage range, protects downstream equipment in the monitoring system more reliably, and effectively ensures the safety operation of the monitoring system.

Description

The transient overvoltage protection device of high energy consumption monitoring system

Technical field

The utility model belongs to industrial automatic control field, particularly a kind of transient overvoltage protection device of high energy consumption monitoring system.

Background technology

Overvoltage protection is the important component part of industrial automation, and meanwhile, the high energy consumption smelting industry overwhelming majority is all manual operation control, unrealized automatic control mode, but to realize automatic control, monitoring system is essential.For electric arc furnace smelting system, due to the requirement of smelting process, high-tension transformer needs continuous start and stop, and like this, voltage transformer secondary side and arc furnace electrode place will instantaneous overvoltages, and the upstream device of monitoring system is damaged.And existing transient overvoltage protection device is not very applicable to high energy consumption monitoring system.So the problem facing is exactly that the fail safe of monitoring system upstream device under over-voltage condition cannot guarantee.In high energy consumption smelting industry energy-consumption monitoring system, need a kind of transient overvoltage protection device, guarantee the security reliability of its operation.

Summary of the invention

The purpose of this utility model is to provide a kind of transient overvoltage protection device of high energy consumption monitoring system, and upstream device that can anti-locking system damages, and guarantees the security reliability of this monitoring system.

A transient overvoltage protection device for high energy consumption monitoring system, this protective device is comprised of accurate tranformer protection mechanism and analog input card protection mechanism; Precision tranformer protection mechanism comprises: high-voltage signal input terminal, 3W51K dead resistance, 1.5KE250 bidirectional transient voltage suppressor TVS, high-voltage signal lead-out terminal, accurate transformer, and they are connected with smelting arc furnace electrode place successively; Analog input card protection mechanism comprises: low-voltage signal input terminal, 1W51K dead resistance, SMBJ12CA bidirectional transient voltage suppressor TVS, low-voltage signal lead-out terminal, NI analog input card, and they are connected with voltage transformer successively;

Native system is assemblied on ac voltage signal circuit; when the two poles of the earth of bidirectional transient voltage suppressor TVS are subject to reverse transient state high energy impact events; it enters reverse blocking state immediately; can be with 10 the speed of bearing 12 power second-times; the high impedance of its two interpolar is become to Low ESR; and instantaneous high-energy mainly drops on dead resistance; can absorb fast like this surge power up to thousands of watts; make the voltage clamping of two interpolars in a predetermined value, can protect upstream device to avoid various surge pulse shocks.

Protective device of the present invention has the following advantages:

1. high/low pressure signal input/output terminal adopts screw type binding post, and the class of insulation is high, durable, volume is little, easy-to-connect;

2. dead resistance adopts 1W/3W51K-1% metalfilmresistor, can rapidly instantaneous voltage be consumed;

3. adopt 1.5KE250, SMBJ12CA bidirectional transient voltage suppressor TVS, there is self-recovering function, work in reverse blocking state, AC signal is carried out to instantaneous overvoltage inhibition, do not affect any function of system;

4. bidirectional transient voltage suppressor TVS coordinates dead resistance, has more reliably effectively protected upstream device;

5. little, the power of bidirectional transient voltage suppressor TVS volume is large, response is fast, noiseless and price low;

6. this system cost is low, simple and practical, volume is little, easy to use, only need be serially connected in AC signal.

Accompanying drawing explanation

Fig. 1 is the structured flowchart of accurate tranformer protection mechanism in the utility model protective device;

Fig. 2 is the structured flowchart of analog input card protection mechanism in the utility model protective device.

Embodiment

The embodiment of the transient overvoltage protection device below in conjunction with accompanying drawing to the utility model high energy consumption monitoring system is described in more detail.

As shown in Figure 1 and Figure 2, the transient overvoltage protection device of high energy consumption monitoring system, this protective device is comprised of accurate tranformer protection mechanism and analog input card protection mechanism.Precision tranformer protection mechanism comprises: high-voltage signal input terminal, 3W51K dead resistance, 1.5KE250 bidirectional transient voltage suppressor TVS, high-voltage signal lead-out terminal, accurate transformer, they are connected with smelting arc furnace electrode place successively.Analog input card protection mechanism comprises: press signal input terminal, 1W51K dead resistance, SMBJ12CA bidirectional transient voltage suppressor TVS, low-voltage signal lead-out terminal, NI analog input card, they are connected with voltage transformer successively.

In actual use, according to Fig. 1, Fig. 2, be made into printed circuit board (PCB) (pcb board).The operation principle of the utility model protective device is: native system is assemblied on ac voltage signal circuit, when the two poles of the earth of bidirectional transient voltage suppressor TVS are subject to reverse transient state high energy impact events (instantaneous overvoltage), it enters reverse blocking state immediately, can be with 10 the speed of bearing 12 power second-times, the high impedance of its two interpolar is become to Low ESR, and instantaneous high-energy mainly drops on dead resistance, can absorb fast like this surge power up to thousands of watts, make the voltage clamping of two interpolars in a predetermined value, effectively protect upstream device, avoid the damage of various surge pulses (instantaneous overvoltage).In high energy consumption monitoring system, by maximum reverse pulse peak current and the overvoltage multiple of TVS, the resistance that calculates dead resistance must not be less than 50K, selects 51K; The power of resistance must not be less than 3W(high pressure) and 1W(low pressure).When high-voltage signal overvoltage, 1.5KE250 bidirectional transient voltage suppressor TVS by signal voltage clamper in maximum clamp voltage 360V(amplitude), effectively protect 250/5V(effective value) accurate transformer; When low-voltage signal overvoltage, SMBJ12CA bidirectional transient voltage suppressor TVS at maximum clamp voltage 14.7V, protects voltage withstand class to be ± 30V signal voltage clamper effectively, the NI analog input card of be input as ± 10V.

The utility model transient overvoltage protection device has adopted Transient Voltage Suppressor TVS to coordinate dead resistance, has solved the security reliability of high energy consumption monitoring system operation.

Claims (1)

1. a transient overvoltage protection device for high energy consumption monitoring system, is characterized in that: described protective device is comprised of accurate tranformer protection mechanism and analog input card protection mechanism;

Described accurate tranformer protection mechanism comprises: high-voltage signal input terminal, 3W51K dead resistance, 1.5KE250 bidirectional transient voltage suppressor TVS, high-voltage signal lead-out terminal, accurate transformer, and they are connected with smelting arc furnace electrode place successively;

Described analog input card protection mechanism comprises: low-voltage signal input terminal, 1W51K dead resistance, SMBJ12CA bidirectional transient voltage suppressor TVS, low-voltage signal lead-out terminal, NI analog input card, and they are connected with voltage transformer successively;

Native system is assemblied on ac voltage signal circuit; when the two poles of the earth of bidirectional transient voltage suppressor TVS are subject to reverse transient state high energy impact events; it enters reverse blocking state immediately; can be with 10 the speed of bearing 12 power second-times; the high impedance of its two interpolar is become to Low ESR; and instantaneous high-energy mainly drops on dead resistance; can absorb fast like this surge power up to thousands of watts; make the voltage clamping of two interpolars in a predetermined value, can protect upstream device to avoid various surge pulse shocks.

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