CN2071834U - Multifunction protective switch - Google Patents

Abstract

The utility model relates to a multifunction protective switch which is used in an electric power network to carry out the make-break operation and protection, which comprises a protector for short circuit and overload, a leakage protection circuit, a three-phase unbalance and open phase protection circuit, and an undervoltage protection circuit. The signal voltage generated by each circuit generates the trigger voltage after compared with a voltage comparator to trigger a thyristor so that a trip acts to cut off power supply. The utility model has the characteristics of complete protection function, simple circuit, little dispersion, reliable performance, high sensitivity, high anti-interference capability, etc.

Description

Multifunction protective switch

The utility model relates to a kind of factory floor, mine motor-pumped well of being widely used in; the threshing ground, rural area; occasions such as architectural electric are done make-break operation; electric leakage and personal electrical shock protection, under-voltage in the circuit, phase shortage, imbalance of three-phase voltage protection and the overload of circuit and motor and the multifunction protection switch of short-circuit protection.

In the prior art, commercially available prod DZ15L series earth leakage circuit breaker has overload, short circuit and creepage protection function, and this product once obtained nineteen eighty-two country's invention of great significance second prize.Its overload, short-circuit protection all adopt electromagnetic hydraulic pressure formula release, no electronic component.This product has and is active in one's movements, characteristics such as operate time is fast, and inverse time characteristic is good, and volume is little, and breaking current is big, but its these three kinds of defencive functions can not satisfy the needs of multi-faceted protection in the electrical network.The leakage protection circuit of this product adopts resolution element to constitute, and is subjected to the influence of extraneous factors such as temperature, electromagnetic interference bigger.The utility model is exactly that the deficiency of and leakage protection circuit few at this product function is improved.

It is the more complete multifunction protection switch of one, function that one of the purpose of this utility model provides a kind of double overload, short circuit, electric leakage, three-phase imbalance, phase shortage and under-voltage protection; two of the purpose of this utility model is to make the index of each function can independently control adjustment, and accomplish that circuit is simple, discreteness is little, dependable performance, highly sensitive, antijamming capability is strong.

The purpose of this utility model can realize by following scheme: increased a three-phase imbalance and open-phase protection circuit on the basis of former earth leakage circuit breaker; under-voltage protecting circuit and DC power supply circuit; leakage protection circuit; three-phase imbalance and open-phase protection circuit and under-voltage protecting circuit are respectively by the zero sequence current mutual inductor circuit; symmetry star load circuit and three-plase half wave rectifier circuit are obtained signal voltage; through voltage comparator relatively after; produce trigger voltage; trigger controllable silicon; make the release action, the direct-current working volts of entire circuit are taken out by under-voltage protecting circuit.

Operation principle of the present utility model as shown in Figure 1, L1 is that zero sequence current mutual inductor is secondary among the figure, elementary for passing its three-phase phase line and a neutral line (zero line), when normal nothing is leaked electricity, flow through the elementary electric current of zero sequence current mutual inductor and be combined into zero, the resultant flux amount is zero, therefore, the in-phase input end 7 of voltage comparator LM339 is given birth in the influence electricity miscarriage among the secondary L1 ^#Non-inductive voltage.Because the inverting input 6 of this comparator ^#A fixed voltage (100MV) is arranged, through comparing its output 1 ^#Be " 0 " current potential, the controllable silicon Triggerless, release is failure to actuate.When human body contacts live wire (or the live wire of load and the earth electric leakage), equal live wire and increased a passage with ground, shock current directly leaks to the earth from live wire, make that resultant current is non-vanishing in the zero sequence current mutual inductor, therefore the resultant flux amount no longer is zero, the secondary L1 of zero sequence current mutual inductor produces induced current immediately, produces voltage drop by resistance R 2, inputs to the in-phase input end 7 of comparator ^#, output potential overturns at this moment, becomes " 1 " current potential by " 0 " current potential, and this signal voltage is by diode D ₈Remove to trigger controllable silicon, make the release action, cut off three phase mains, play the earth leakage protective effect.

The signal voltage of three-phase imbalance protective circuit is obtained by the symmetrical star load circuit that resistance R 7, R8, R9 form.When the three phase mains balance, the neutral point current potential of its balanced load is zero, and no current passes through on the resistance R 10, so absence of voltage.When three phase mains was uneven, its neutral point current potential no longer was zero, thereby produced a unbalance voltage on resistance R 10, inputed to the inverting input 8 of comparator ^#, this voltage is as greater than 100MV, and " 1 " when then this comparator output potential is by three-phase equilibrium becomes " 0 ", and the delay circuit time-delay 5-10 that forms through R19, C7 is input to this electronegative potential the input 4 of another comparator after second ^#, make this comparator upset, produce a trigger voltage, trigger controllable silicon, make the release action, accomplish the three-phase imbalance protection.

The principle of open-phase protection is the same, because phase shortage belongs to more serious imbalance, is the special circumstances of three-phase imbalance.After the three-phase imbalance protective circuit is adjusted, must play the open-phase protection effect.

Supply voltage is after three-plase half wave rectifier circuit D2, D3, D4 rectification, and after resistance R 13, R14 dividing potential drop, the signal voltage of generation inputs to comparator in-phase input end 11 ^#The inverting input of this comparator is a fixed voltage (2V), when supply voltage hangs down to a certain value (being generally 70%Ue), voltage after the rectification is after dividing potential drop, be lower than the inverting input voltage of comparator, the comparator output potential becomes " 0 " current potential by original " 1 " current potential, delays time 5-10 after second through the delay circuit that R19, C7 form, and this " 0 " current potential is inputed to the inverting input 4 of another comparator ^#, make the output of this comparator become " 1 " by " 0 ", the trigger voltage of generation triggers controllable silicon through diode D9, makes the release action, reaches the under-voltage protection effect.

The direct-current working volts of entire circuit are taken out by under-voltage protecting circuit, by D2, D3, D4 three phase half wave rectification and can obtain+the 5V DC power supply after voltage stabilizing didoe D5 and capacitor C 6 voltage stabilizings and filtering.

Advantage of the present utility model and effect are significantly, and it integrates various GPF (General Protection False functions, overcome existing various protection switch defencive functions few, with the defective of several protector simple combination; The protection index of each defencive function of the present utility model can independently be adjusted, this is because the protective circuit of each function all is relatively independent in entire circuit, therefore can carry out the index adjustment according to user's various different demands, can in the 60%-90%Ue voltage range, adjust as the under-voltage protection index, thereby enlarge the scope of application of this product; Leakage protection circuit of the present utility model has overcome the residual operating current instability that existing electronic circuit has, there is a phase shortage just to cause defectives such as creepage protection function inefficacy, electric leakage signal enters comparator by filtering, anti-jamming circuit, thereby reduced circuit and be subjected to extraneous factor, influence as temperature, magnetic field etc., and parameter does not change with the fluctuation of electrical network, voltage, can guarantee the operate as normal of protective circuit under power supply circuits phase shortage situation; Because under-voltage protection of the present utility model adopts independently under voltage protection circuit, therefore, the under voltage operating value can independently be adjusted, and is not only simple and reliable for structure, and can be entire circuit direct-current working volts are provided; Three-phase imbalance of the present utility model and open-phase protection circuit have overcome defectives such as prior art open-phase protection insensitive (especially under the high situation of voltage) and poor anti jamming capability, make this circuit not be subjected to the influence of fluctuations of line voltage, and can independently adjust the operation voltage of three-phase imbalance value as required; Because the utility model adopted integrated circuit and controllable silicon directly to drive, therefore, characteristics such as this product also has simple in structure, and discreteness is little, and dependable performance is highly sensitive, and volume is little.

Fig. 1 is an electrical schematic diagram of the present utility model.

Fig. 2 is a structural representation of the present utility model.

Fig. 3 is a multifunction protection tripper structure schematic diagram.

Below in conjunction with accompanying drawing the utility model is described more specifically.

Concrete structure of the present utility model as shown in Figure 2, it comprise the short circuit, overload protection arrangement of commercially available prod DE15L circuit breaker and improve after leakage protection circuit.Short circuit and overload protection arrangement are to be made of three hydraulic electromagnetic releases 1; the hydraulic electromagnetic release is made of magnet exciting coil, the stem stem that silicone oil is housed, armature and retracting spring; it directly and three-phase power line join; when load short circuits or overload; the electric current that flows through magnet exciting coil reaches its operating value; the magnetic force that magnet exciting coil produces just attracts armature, and promotion dropout pull bar makes the switch disconnection, the cut-out electric current.As shown in Figure 1, described leakage protection circuit comprises that electric leakage signal detects, voltage ratio reaches three parts of leak(age) test.Electric leakage signal voltage is obtained by zero sequence current mutual inductor L1, L2, it is the permalloy magnet ring of an annular, be wound with the secondary coil of 1000 circles on it, the primary coil of instrument transformer then is to pass its each the phase main power source phase line and the secondary coil two ends of zero line, zero sequence current mutual inductor and be connected to semifixed resistor R2, change the resistance of R2, induced voltage is changed.Therefore, regulate this resistance and can set the leakage current protection value.R2 one end ground connection, the other end is connected to the in-phase input end 7 of one of them comparator of integrated voltage comparator LM339 by current-limiting resistance R3 ^#, and the inverting input 6 of this comparator ^#Then take out the voltage of 100MV as its reference voltage from direct current+5V voltage by divider resistance R3, R4, for preventing High-frequency Interference, two input cross-over connections at above-mentioned comparator have capacitor C 1, and the signal voltage of obtaining from zero sequence current mutual inductor directly enters voltage comparator after capacitor C 1 filtering.The output 1 of comparator ^#Receiving controllable silicon D7 control through diode D8 extremely goes up.Filter capacitor C2 bypasses High-frequency Interference over the ground, and+5V voltage is connected to the output of comparator by resistance R 6, and its effect is to stablize output potential.For whether the running check creepage protection function is intact, the spy is provided with a leak(age) test circuit.It is the elementary winding L 2 of being furnished with one 6 circle on the primary coil of zero sequence current mutual inductor, be used to produce the simulation electric leakage signal of leak(age) test circuit, one end of this winding is received on the zero-power line by current-limiting resistance R1, and the other end is received any one of three phase mains by a sensitive switch K1 who is made up of normally opened contact and gone up mutually.Therefore press test button, have electric current to flow through the elementary of zero sequence current mutual inductor, be equivalent to an electric leakage signal, just can check creepage protection function whether intact and tripping mechanism and reliably disjunction of contact at any time.

Key problem in technology of the present utility model also is to have increased a three-phase imbalance and open-phase protection circuit, under-voltage protecting circuit and DC power supply circuit.Above-mentioned each circuit as shown in Figure 1, resistance R 7, R8, R9 and semifixed resistor R10 form three symmetrical star load circuit in described three-phase imbalance and the open-phase protection circuit, are used for the detection of unbalanced signal voltage.Signal voltage is obtained by this circuit and resistance R 10, is connected to the inverting input 8 of voltage comparator through current-limiting resistance R11 ^#, this comparator in-phase input end 9 ^#Inverting input 6 with the electrical leakage voltage comparator ^#Be connected, with 100MV voltage as reference voltage.For preventing High-frequency Interference, at two input cross-over connection filter capacitor C3 of comparator, its output 14 ^#Be connected with the output of under-voltage comparator.

The three-plase half wave rectifier circuit rectification that described under-voltage protecting circuit is made up of diode D2, D3, D4, and after resistance R 13, R14 dividing potential drop, obtain a under-voltage signal voltage, after capacitor C 5 filtering, receive the in-phase input end 11 of under-voltage voltage comparator ^#, and inverting input 10 ^#In-phase input end 5 with another comparator ^#Link to each other, obtain+reference voltage of 2V its output 13 ^#Output 14 with the unbalance voltage comparator ^#Link to each other.

In under-voltage protecting circuit of the present utility model, also be provided with DC power supply circuit; be used to entire circuit that direct-current working volts are provided; this circuit is made up of D2, D3, D4, R17, R18, D5 and C6; supply voltage is after the three-plase half wave rectifier circuit rectification that D2, D3, D4 form, by R17, R18 and C6 capacitance-resistance filter and promptly can be circuit through the D5 voltage stabilizing and provide+direct-current working volts of 5V.

For avoiding causing the misoperation of protection switch owing to the instantaneous voltage fluctuation of electrical network; output at three-phase imbalance protective circuit and under-voltage protecting circuit is provided with one two delay circuit that circuit is common; this circuit is made up of R19, C7; after delay circuit 5-10 delays time second, import the inverting input 4 of another comparator by the voltage of three-phase imbalance and under-voltage voltage comparator output ^#, make this comparator upset, produce trigger voltage, trigger controllable silicon through diode D9, make the release action.

As shown in Figure 2, each circuit of the present utility model all is arranged on the control circuit board 6.Main power source lead-in wire 3 passes zero-sequence transformer 4, and is connected to the power outlet binding post.The utility model removes and adopts three overload protection releases 1, outside overload, short-circuit protection, also is provided with a multifunction protection release 7, and it is the actuator of electric leakage, three-phase imbalance and phase shortage and under-voltage protecting circuit.Release links to each other with control circuit board 6 by lead 2, its structure as shown in Figure 3, it is made up of coil stem stem 7a, magnet exciting coil 7b, framework 7C, retracting spring 7d and armature 7e, is a kind of electromagnetic release.Armature 7e links to each other with dropout pull bar 8, and the dropout pull bar links to each other with the free tripping mechanism 9 of switch.When control circuit board sent actuating signal, the magnet exciting coil of multifunction protection release flow through electric current, and produced magnetic force, adhesive armature, and pulling dropout pull bar makes the free tripping mechanism action of switch, cuts off the electricity supply.

Claims (5)

1; a kind of multifunction protection switch that is used for doing make-break operation and protection at electric power network; it comprises leakage protection circuit; short-circuit protection and overload protection arrangement; it is characterized in that it also has a three-phase imbalance and open-phase protection circuit; under-voltage protecting circuit and DC power supply circuit; said leakage protection circuit; three-phase imbalance and open-phase protection circuit and under-voltage protecting circuit are respectively by the zero sequence current mutual inductor circuit; symmetry star load circuit and three-plase half wave rectifier circuit are obtained signal voltage; through voltage comparator relatively after; produce trigger voltage; trigger controllable silicon; make the release action, the direct-current working volts of entire circuit are taken out by under-voltage protecting circuit.

2, multifunction protection switch as claimed in claim 1 is characterized in that the electric leakage signal voltage of being obtained by zero sequence current mutual inductor directly enters voltage comparator after filter capacitor C1 filtering.

3, multifunction protection switch as claimed in claim 2 is characterized in that said zero sequence current mutual inductor adopts the permalloy magnet ring.

4, multifunction protection switch as claimed in claim 2 is characterized in that described voltage comparator adopts integrated four voltage comparators.

5, multifunction protection switch as claimed in claim 1 is characterized in that three-phase imbalance and open-phase protection circuit, under-voltage protecting circuit trigger controllable silicon after the delay circuit time-delay that the trigger voltage that voltage comparator produces is formed by R19, C7.

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