CN201536343U

CN201536343U - Energy-saving protective device of novel electromotor

Info

Publication number: CN201536343U
Application number: CN2009200661704U
Authority: CN
Inventors: 刘晓文
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-09-30
Filing date: 2009-09-30
Publication date: 2010-07-28
Anticipated expiration: 2019-09-30

Abstract

The utility model relates to an energy-saving protective device which controls a three-phase alternating current motor to realize the star/triangle conversion during operation. The energy-saving protective device comprises a comparator for comparing sampled signals by a sample circuit of an electromotor line current, a delay circuit and an electronic switch and is characterized in that the protective device is added with a conversion delay circuit and a start delay circuit; the electronic switch is connected with the conversion delay circuit and the start delay circuit; and the protective device is also provided with an adjustable reference signal setting circuit and an indicator light display circuit. The protective has the advantages of strong capability of resisting disturbance, stable electromotor operation, stronger adaptability, convenient regulation and usage, and the like, and has better economic and social benefits.

Description

Novel motor energy-saving protective device

Technical field

The utility model relates to control device of electric motor.

Background technology

Three-phase alternating-current motor, particularly big-and-middle capacity motor moves under delta connection mostly.Often have operating modes such as zero load, underloading to occur in the actual moving process of motor, this kind operating mode causes the part electric energy to be wasted.Traditional motor energy saving devices can make motor carry out the star/triangle conversion according to the variation of motor load.This conventional apparatus comprises that the sample circuit of a motor line electric current, reference signal initialization circuit, one are used for comparator that aforementioned reference signal compares sampled signal and the electronic switch that is controlled by comparator output signal, are connected to the auxiliary relay of control motor star/triangle change-over circuit on this electronic switch.And this conventional apparatus is subject to the fluctuation of line voltage and the factors such as instantaneous variation of load are disturbed, and causes the sampled signal instantaneous variation, causes the auxiliary relay frequent movement, causes the motor fluctuation of service on the contrary.In addition, the reference signal voltage of this battery saving arrangement immobilizes, and can only be applicable to a certain motor.

Summary of the invention

It is bad that the utility model can solve traditional battery saving arrangement job stability, the problem that adjustable range and applicable surface are narrow.

This energy saving motor protective device comprises the sample circuit of a motor line electric current, a reference signal initialization circuit, a comparator that sampled signal is compared with reference signal, the electronic switch that is controlled by comparator, on this electronic switch, be connected to the relay of control motor star/triangle change-over circuit, it is characterized in that: the output of motor line current detecting sampled signal device one current transformer H1 is connected by the negative input end of current rectifying and wave filtering circuit with reference signal input comparator IC1, and the positive input terminal of comparator IC1 is by potentiometer W2, W3 and DC power supply+the 12V end is connected; The output of described reference signal input comparator IC1 is connected to an anti-interference delay circuit IC2; The input that other has a startup delay circuit identical with disturbing delay circuit IC2 structure and described transformation rectifier power source+12V holds and is connected; Described two delay circuit IC2, IC3 are connected with collector electrode, the base electrode of the triode BG13 of electronic switching by diode BG9, BG10 respectively, and described relay J 1 is serially connected in the collector electrode of BG13; Another contact of described J1 is star/triangle conversion and control contact J1-2; The output of described two delay circuit IC2, IC3 is connected with the positive input terminal of another voltage comparator ic 4 by diode BG9, BG10 respectively; Have an indicator light BG12 to be parallel to relay J 1 two ends, have another red indicator light BG14 be serially connected in voltage comparator ic 4 output and+12V is between the power end; The reference voltage input of described delay circuit IC2 and voltage comparator ic 4 is connected with described+12V power supply.

The utility model is owing to adopted the signal lag measure, and benchmark is adjustable, so antijamming capability is strong, the operating ratio of motor is more steady, and adaptability is stronger, regulates easy to use.

Description of drawings

Fig. 1 is the circuit theory diagrams of a kind of energy saving motor protection unit described in the utility model.

Embodiment

As Fig. 1 institute method: sample circuit 1 is made up of the current transformer H1 and the current rectifying and wave filtering circuit that are connected on a certain power supply of motor, it converts the line current of motor to d. c. voltage signal input comparator IC1, the reference signal initialization circuit is made up of the DC power supply, potentiometer W4, variable resistor W2, the W3 that join with motor power, and wherein potentiometer W4 is connected in series with resistance W2, W3 by normally open contact J1 and the normally closed interlock J2 of auxiliary relay J respectively.Voltage division signal on the potentiometer W4 is promptly as reference signal input comparator IC1, when the coil blackout of middle relay J or energising, potentiometer W4 will be connected in series with resistance W2 or resistance W3, thereby have two relatively reference signals of usefulness, and they correspond respectively to the star or the delta-connection of motor.When reality is used, set reference signal in the ratio of shared motor rated current.As set of 45% o'clock (light running) of the actual line electric current of motor less than its rated current, motor converts the star operation to from triangle; When 55% (heavy service) of actual current greater than rated current, motor converts the triangle operation to from star, be that motor has two operation transfer points, thereby form certain transition width, make motor operation stable (also can only establish a transfer point) more according to actual conditions.Can obtain different transfer points by regulator potentiometer W4 with resistance W2, W3.

Output at comparator IC1 is connected to an anti-interference delay circuit, and it is made up of adjustable resistance W5, capacitor C 5, diode BG7 and comparator IC2.The effect of this delay circuit is to eliminate motor current because of the interference that certain reason generation instantaneous variation is produced, and avoids the unnecessary frequent movement of relay.The structure that starts delay circuit is identical with delay circuit, and it and DC power supply are joined.Two delay circuits join by AND circuit and the electronic switch BG13 that is made up of diode BG9, BG10, and during motor start-up, starting current is very big, and this sudden change can in time be reflected on the DC power supply.But because the startup delay circuit is arranged, diode BG10 left end is an electronegative potential during motor start-up, triode BG13 ends, auxiliary relay J outage, motor starts under star connection, when when motor start-up finishes, going into normal commentaries on classics, delay circuit is ineffective, and diode BG10 left end is in high potential, and the state of triode BG13 will depend on the state of diode BG9 at this moment, when electromotor heavy load moves, sampled signal voltage is greater than reference signal, and diode BG9 left end is a high potential, triode BG13 conducting, auxiliary relay J energising, motor moves under delta connection; When motor became light running by heavy duty, sampled signal voltage was less than reference signal, and diode BG9 left end is an electronegative potential, and triode BG13 ends, and motor transfers the star connection operation to by triangle.

Claims

1. electric function protective device, it comprises the sample circuit of a motor line electric current, a reference signal initialization circuit, a comparator that sampled signal is compared with reference signal, the electronic switch that is controlled by comparator, on this electronic switch, be connected to the relay of control motor star/triangle change-over circuit, it is characterized in that: the output of motor line current detecting sampled signal device-current transformer H1 is connected by the negative input end of current rectifying and wave filtering circuit with reference signal input comparator IC1, and the positive input terminal of comparator IC1 is by potentiometer W2, W3 and DC power supply+the 12V end is connected; Described two delay circuit IC2, IC3 are connected with collector electrode, the star utmost point of the triode BG13 of electronic switching by diode BG9, BG10 respectively, and described relay J 1 is serially connected in the collector electrode of BG13; Another contact of described J1 is star/Samsung conversion and control contact J1-2; The output of described two delay circuit IC2, IC3 is crossed diode BG9, BG10 respectively and is connected with the positive input terminal of another voltage comparator ic 4; Have an indicator light BG12 to be parallel to relay J 1 two ends, have another indicator light BG14 be serially connected in voltage comparator ic 4 output and+the 12V power end between; The reference voltage input of described delay circuit IC2 and voltage comparator ic 4 is connected with described+12V power supply.

2. novel motor energy-saving protective device according to claim 1 is characterized in that: adopted two delay circuit IC2, IC3 to link to each other with the triode BG13 that plays the electronics on-off action by diode BG9, BG10 respectively.

3. novel motor energy-saving protective device according to claim 1 is characterized in that: adopted adjustable reference signal initialization circuit, it is made up of the DC power supply, potentiometer W4, variable resistor W2, the W3 that join with motor power.