CN2297022Y

CN2297022Y - Three-phase protector for error phase and short phase

Info

Publication number: CN2297022Y
Application number: CN 97214630
Authority: CN
Inventors: 胡克海
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-05-21
Filing date: 1997-05-21
Publication date: 1998-11-11
Anticipated expiration: 2007-05-21

Abstract

The utility model relates to a three-phase protector for error phase and short phase. The utility model is composed of a power supply, a testing circuit and a control circuit. The utility model is characterized in that a thyristor is used as a testing element; a photoelectric coupler is used as a signal transmission element; each anode and control end of the thyristor are independently connected with each phase line of the measured power supply; a sampling resistor is arranged between the anode of the thyristor and the phase line of the power supply; the input end of the photoelectric coupler is connected with the sampling resistor in parallel; the output end of the photoelectric coupler is connected with the power supply loop of the control circuit in series; the control circuit adopts a switch circuit which is composed of a triode. The utility model can carry out the accurate detection on the error phase and short phase of the phase line of the power, and the utility model has the effective protection on the electric equipment.

Description

Three-phase electricity misphase, open phase protector

The utility model relates to circuit protection device.More particularly, be a kind of that constitute by power circuit, testing circuit and control circuit, be used for power consumption equipment implementing the device of protection when three phase mains phase line generation misphase or the phase shortage.

For some power consumption equipment that adopts three phase mains, power supply misphase or phase shortage can have a strong impact on the operate as normal of equipment, and What is more, and misphase causes the motor counter-rotating, causes the fatefulue damage of equipment.

In the prior art, though open-phase protection circuit is varied, on detection and signal processing, the complex structure that all seems, shortage reliability.Especially the protective device of thermal relay formula, its protection action is after certain heat produces, and the motor of this moment has been subjected to infringement to a certain degree.

By retrieval, the device that present needleless is still protected misphase, and in real work, misphase is owing to the phenomenon of safeguarding or other reason very easily takes place.

The purpose of this utility model is, avoids above-mentioned weak point of the prior art, and a kind of three-phase electricity misphase, open phase protector are provided, so that power consumption equipment misphase or phase shortage are implemented effectively protection.

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

The utility model is made of power circuit, testing circuit and control circuit, and its architectural feature is:

A, employing are that detecting element, photoelectrical coupler N are the testing circuit of signal transmission component with controllable silicon T, anode a1, the a2 of controllable silicon T and control end g are connected to tested power supply each phase line A, B and C independently of each other, respectively, wherein, between anode a1 and power supply phase line A, sampling resistor R3 is set, the photoelectrical coupler input is arranged in parallel at sampling resistor R3 two ends, and photoelectric coupler output end is serially connected in the electric power loop of control circuit;

B, described control circuit adopt the switching circuit that is made of respectively triode T1, T2 and T3, and at switch triode T1, T2 and T3 interpolar cross-over connection stablizing electric capacity C2, C3 and C4.

The utility model adopts single-phase silicon-controlled for detecting no part, and each anode of silicon controlled and control end be connected to each phase line of tested power supply respectively independently of each other, utilize the different phase sequences between each phase line of three-phase alternating current, control one-way SCR ON time is used and is carried out phase sequence discriminating and phase shortage identification.Compared with the prior art, the utility model not only cost reduces greatly, and reliability is greatly improved, and avoids the influence of electric motor starting instantaneous large-current, does not have the problem that motor can't be started owing to the protection motor.Compare with " thermal relay ", the utility model can make power consumption equipment just enter guard mode when not suffering damage because protection is swift in motion in time.In addition, the utility model is a signal transmission component by adopting photoelectrical coupler, makes test side and control end implement electricity and isolates, and by stable electric capacity is set, guaranteed the reliability of circuit working effectively in the control circuit switch triode.

Accompanying drawing is the utility model circuit theory diagrams.

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

Embodiment:

Referring to accompanying drawing, present embodiment is made of power circuit, testing circuit and control circuit.

Employing is that detecting element, photoelectrical coupler N are the testing circuit of signal transmission component with controllable silicon T, anode a1, the a2 of controllable silicon T and control end g are connected to tested power supply each phase line A, B and C independently of each other, respectively, wherein, between anode a1 and power supply phase line A, sampling resistor R3 is set, the photoelectrical coupler input is arranged in parallel at sampling resistor R3 two ends, and photoelectric coupler output end is serially connected in the electric power loop of control circuit;

Control circuit adopts the switching circuit that is made of respectively triode T1, T2 and T3, and at switch triode T1, T2 and T3 interpolar cross-over connection stablizing electric capacity C2, C3 and C4.Wherein capacitor C 2, C3 are connected across respectively between the base stage and emitter-base bandgap grading of triode T1, T2, and capacitor C 4 is connected across base stage and the inter-collector of triode T3.

Shown in the figure, the current stabilization circuit that constitutes by capacitor C 1, diode D1 and resistive element R5 in the setting of controllable silicon T control end.The controllable silicon T that is set to of current stabilization circuit provides stable controllable current.

When power supply signal inserts testing circuit with correct phase sequence, controllable silicon is kept a normal ON time, be created in dividing potential drop sampled signal on the sample resistance R3 through the transmission of photoelectrical coupler N, connect the control circuit electric power loop, switch triode T1, T2 and T3 conducting respectively, the relay J coil gets electric, is serially connected in the relay normally open contact closure in the power consumption equipment electric power loop, for power consumption equipment provides normal working power.Simultaneously, the luminous demonstration of green LED LED1, working properly to show.

In case have the misphase phenomenon to take place, the ON time of controllable silicon T shortens greatly, sample resistance R3 goes up faint voltage division signal, though make the photoelectrical coupler conducting, output current is much smaller than normal phase sequence, triode T1, T2 and T3 thereby end.At this moment, relay coil J dead electricity, its contact keeps open circuit, and power consumption equipment is because the power supply open circuit, and is in protected state.Simultaneously because the ending of triode T2 and T3, red light emitting diodes LED2 light-emitting caution, buzzer L is because not buzzing of parameter adjustment.

When phase shortage, controllable silicon T ends, photoelectrical coupler N non-output signal, and at this moment, owing to three-phase pipe T1, T2, T3 end, green light LED1 extinguishes, by parameter adjustment, red light LED2 light-emitting caution, buzzer L sends chimes of doom simultaneously.

The utility model utilizes its luminous and warning circuit when protection relay J is not set, can be separately as checkout gear.

Claims

1, a kind of three-phase electricity misphase, open phase protector are made of power circuit, testing circuit and control circuit, it is characterized in that:

2, three-phase electricity misphase according to claim 1, open phase protector is characterized in that, the current stabilization circuit that is made of capacitor C 1, diode D1 and resistive element R5 in the setting of described controllable silicon T control end.