CN2187348Y

CN2187348Y - Protective module for electric machines

Info

Publication number: CN2187348Y
Application number: CN 94237156
Authority: CN
Inventors: 谭锐; 向铁军; 史凤仙
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-04-20
Filing date: 1994-04-20
Publication date: 1995-01-11
Anticipated expiration: 2004-04-20

Abstract

The utility model relates to a protective module for the electric machines which is suitable for various motors, which is composed of a duplicate supply circuit, a current-voltage detecting circuit, a time base comparing circuit, an executive circuit, a base value circuit, and a display circuit. The protective module is formed by a special encapsulation. The protective module for the electric machines can delay 6 to 14 minutes to protect, when the current is larger than 1.2 times. The protective module for the electric machines can delay 1 minute to protect, when the current is larger than 1.5 times. The protective module for the electric machines can instantaneously protect, when the current is larger than 6 times, the phase failure and the three-phase unbalance can be executed instantaneous protection, and the overcurrent caused by the temperature can be protected. The utility model has the advantages of complete function and reliable performance, the protected accuracy is 1% more or less, and can be used under any environment.

Description

Protective module for electric machines

The utility model is a kind of electric motor protecting module that is applicable to all kinds of motor.

Now, the employed protector of motor, major part belongs to the individual event protection.As thermal relay, phase failure protector, overcurrent protector, temperature protector etc.Lack omnibearing protection, these protectors are subject to ambient temperature, humidity effect simultaneously, and reliable in action is poor, and the electric motor protecting module that has omnibearing protection function, reliable operation safety at present still belongs to blank.

The purpose of this utility model provides a kind of electric motor protecting module with defencive functions such as overcurrent, overvoltage, the phase failure, three-phase imbalance, dependable performance.

The utility model is achieved in that the electric motor protecting module is by the two-supply circuit that 8V and 24V are provided, the base value circuit, voltage and current detection circuit, compare time-base circuit, executive circuit, fault display circuit is formed, voltage detecting adopts the three-phase no-voltage to make the instantaneous protection of the phase failure and three-phase imbalance, current detecting adopts the current transformer sampling respectively through bridge rectifier, get its three-phase current maximum and send into the comparison time-base circuit, relatively time-base circuit is by 556 dual time bases, LM339 comparator and 4,066 four path analoging switch are formed, wherein three relatively time-base circuits protections in 6--14 minute of can delaying time when relatively current value is greater than 1.2 times respectively, can delay time during greater than 1.5 times and protect in 1 minute, but instantaneous protection during greater than 6 times, its output signal 23 is sent into the executive circuit of being made up of electric light coupling and relay, the control performer; The base value circuit provides reference voltage by electric resistance partial pressure; Display circuit is by each faulty circuit of diode displaying, and LM339,556 and 4066 devices all adopt the COMS integrated circuit, and all circuit forms the electric motor protecting module through special package.

This protection module; can follow the tracks of detection to the running status of motor; when any faults such as motor generation overcurrent, overvoltage, under-voltage, the phase failure, three-phase imbalance; this module all can be sent signal; cut off motor power; with the realization omnibearing protection, and provide corresponding indication, to find out failure cause rapidly.The characteristics of this module are that current of electric is protected by anti-time limit characteristic; when electric current greater than 1.2 times time time-delay cut off the electricity supply after 6--14 minute; but electric current greater than 1.5 times time time-delay cut off the electricity supply after 1 minute, but electric current during greater than 6 times then instantaneous protection cut off the electricity supply immediately.Because device adopts the COMS integrated circuit, strong anti-interference performance, dependable performance, multiple functional, protection precision can reach ± and 1%, because it is contactless operation, and adopts special package technology, can use in any environment, be applicable to various types of motors.

Below in conjunction with accompanying drawing the utility model is described in further detail:

Fig. 1 is the functional-block diagram of electric motor protecting module;

Fig. 2 is two-supply circuit, voltage and current detection circuit, the line map of executive circuit;

Fig. 3 is for comparing time-base circuit figure;

Fig. 4 is display circuit figure;

Fig. 5 is the base value circuit diagram.

Form by two-supply circuit, voltage and current detection circuit, comparison time-base circuit, executive circuit, base value circuit and display circuit with reference to Fig. 2, Fig. 3 electric motor protecting module.Two-supply circuit is formed the 24V DC power supply by transformer (B11), bridge rectifier (D1--4), voltage-stabiliser tube (T1), filter capacitor (C1--C3); Bridge rectifier (D5--8), voltage-stabiliser tube (T2), filter capacitor (C4--5) are formed the 8V DC power supply.Current detection circuit is formed three-phase current sample circuit (as Fig. 2) respectively by three current transformers (LA, LB, LC), three bridge rectifiers (D13--16, D17--20, D21--24), three filters (R3.C7, R5.C8, R7.C9) and three diodes (D10--12), and its output signal (26) is sent into comparison time-base circuit (as Fig. 3).This circuit is made up of four LM339 comparators (U1:A, B, C, D), 556 dual time bases and 4,066 four path analoging switch (U3:A, B, C, D); when electric current during greater than 1.2 times; its signal (26) is sent into the comparison time-base circuit of being made up of comparator (U1:C), base (U2:B), four path analoging switch (U3:B, D), resistance (R18--21), electric capacity (C12--13) at 556 o'clock; its time-delay is 6--14 minute, and time-delay back signal (23) is sent into executive circuit protection.Electric current is during greater than 1.5 times; its signal (26) is sent into the comparison time-base circuit of being made up of comparator (U1:D), base (U2:A), four path analoging switch (U3:A, C), resistance (R13--17), electric capacity (C10--11) at 556 o'clock; its time-delay is 1 minute, and time-delay back signal (23) is sent into executive circuit protection.Electric current is during greater than 6 times, and its signal (L6) is sent into comparator (U1:B), and its output signal (26) is sent into display circuit, and sends into executive circuit by L5 after 4N25 electric light coupling (G2) amplifies, and carries out instantaneous protection.Can protect equally by the overcurrent that temperature causes.Voltage detecting circuit is made up of resistance (R8--10), bridge rectifier (D25--28), resistance (R11--12); its voltage signal (25) is sent into LM339 comparator (UI:A); its output signal (L7) is sent into display circuit; and after electric light coupling (G2) amplifies, send into executive circuit by L5, carry out the phase failure and three-phase imbalance instantaneous protection.Executive circuit is made up of 4N25 electric light coupling (G1), diode (D9), closed type relay (JZ1), the starter of its output (S1, S2) control motor.The base value circuit (as Fig. 5) provide reference voltage, it supplies with comparator (U1:D) by the 24V DC power supply through resistance (R26, R29) dividing potential drop output E1, E2 supplies with comparator (U1:C) through the output of resistance (R27, R30) dividing potential drop, and E3 supplies with comparator (U1:B) through the output of resistance (R28, R31) dividing potential drop.Display circuit is made up of light-emitting diode (LED1--5) and resistance (R22--25), but 1.2 times, 1.5 times, 6 times of display power supplies, electric current, and the phase failure or three-phase imbalance indication can be found out failure cause rapidly by display circuit.Above-mentioned whole circuit forms the electric motor protecting module through special package.Because device adopts COMS integrated circuit, strong anti-interference performance.Dependable performance, defencive function are complete, are applicable to various types of motors.

Claims

1, a kind of electric motor protecting module that is applicable to all kinds of motor, it is made up of the two-supply circuit that 8V and 24V are provided, voltage and current detection circuit, comparison time-base circuit, executive circuit, base value circuit and display circuit, it is characterized in that voltage detecting adopts the three-phase no-voltage to make the instantaneous protection of the phase failure and three-phase imbalance; Current detecting adopts current transformer (LA; LB; LC) respectively through bridge rectifier; get its three-phase current maximum and send into the comparison time-base circuit; relatively time-base circuit is by LM339 comparator (U1:A; B; C; D); 556 dual time bases and 4,066 four path analoging switch (U3:A; B; C; D) form; wherein three relatively time-base circuits protections in 6--14 minute of can delaying time when relatively current value is greater than 1.2 times respectively; can delay time during greater than 1.5 times and protect in 1 minute; but instantaneous protection during greater than 6 times; its output signal (23) is sent into by electric light coupling (G1; 2N25) and the executive circuit formed of relay (JZ1); the control performer; LM339; 556 and 4066 devices all adopt the COMS integrated circuit, and all circuit forms the electric motor protecting module through special package.

2, electric motor protecting module according to claim 1, it is characterized in that the comparison time-base circuit forms by four the tunnel: electric current is sent into the comparison time-base circuit of being made up of comparator (U1:C), base (U2:B), four path analoging switch (U3:B, D), resistance (R18--21), electric capacity (C12--13) at 556 o'clock greater than 1.2 times signal (26), and its time-delay is 6--14 minute; Electric current is sent into the comparison time-base circuit of being made up of comparator (U1:D), base (U2:A), four path analoging switch (U3:A, C), resistance (R13--17), electric capacity (C10--11) at 556 o'clock greater than 1.5 times signal (26), and its time-delay is 1 minute; The two output signal (23) is sent into executive circuit; Electric current is sent into comparator (U1:B) greater than 6 times signal (26), and its output signal (L6) is sent into display circuit, and sends into executive circuit by L5 after 4N25 electric light coupling (G2) amplifies, and carries out instantaneous protection; Voltage detection signal (25) is sent into comparator (U1:A), and its output signal (L7) is sent into display circuit, and sends into executive circuit by L5 after electric light coupling (G2) amplifies, and carries out the phase failure and three-phase imbalance instantaneous protection.

3, electric motor protecting module according to claim 1 is characterized in that executive circuit is made up of 4N25 electric light coupling (G1), diode (D9), closed type relay (JZ1), and its output (S1, S2) control motor is cut off the electricity supply.