SU938348A1 - Device for protecting three-phase electric motor against operation in emergency modes - Google Patents

Description

(54) DEVICE FOR PROTECTING A THREE-PHASE ELECTRIC MOTOR AGAINST WORK IN EMERGENCY MODES

one

The invention relates more to protection against emergency operation of electric motors, operating in industry R economic activity.

Devices are known for protecting the ejectors from emergency modes of overheating, short circuit, phase failure, in which the resistance term, current transformer, capacitor effects are used peoncTqptoJe phase-break sensors or dpm of asymmetric mode detection is used by cpei at the motor point, the stat of which is 1FV. With a signal of sensors, the direct current is transmitted to the output switching device in the form of an electromagnetic relay 1 via a direct current circuit.

However, these devices have a significant size, increased consumption of epeco & n and rpik, low stability of some characteristics, power and noise immunity, and the output power of these devices has

low reliability in conditions of aggressive about zuzhakshey sretsch.

A device is known dpy protection of an electric motor containing a sensor

 Emergency signals made in the form of a star from (SEW, the output of which through a rectifier is MEGGEL is connected to the Smitterto-base transition of the transistor, which is connected to the specific circuit 2j.

The closest to the technical support in the achieved result is a device for aaoshty three-way electric motor, containing

The 15th start-up winding coil is connected to the set via a serial VO Jtb cTQip AND KSKxosy upsya, a single cell in the center E.p. & n & and astmctopa, subadicial to thermal sensors, installed on the windings of the electrodes in the Vl 3 J.

In a joint process, control with a mistor is carried out with a free-flow current, which is more effective and desirable from the point of view of heating of the control transition as compared to other control systems, which leads to a split of output / performance characteristics apart from the torrent control system, as well as the control system. Invention Circuit of Invention: the no-demand power and the increase of the jiome of the unit. The goal is achieved by the fact that the device and the three-phase electric motor operating in emergency modes, containing a magnetic starter, whose coil through the Stop button and the button T1usc, connected by a triac, is connected to two facades of the three-phase network, stabilized source and powered, the switch, and the displacer to the two faetas of the three-phase network, stabilized source, powered, the switch, and the receiver. The primary mode in the capacitor star, connected to the power supply wires, or the sensor output through the above aerial bridge is connected to the emitter-base junction of the transistor in the rotor of the threshold electric The output, the output of which, as well as the output of the posistor, is functionally connected with the equiating transition of the triac, is additionally equipped with a bipixig generator with a frequency pulse, at least pores higher than the mast of the supply mains, to HKO.qj - through which a common point of a divider, consisting of a resistor and two posistors connected in series: connected to each other and connected to the output z of the stable source msn-asmi, connected to the emitter and set- transistor mountains as a threshold electric The drawing shows the layout of the device, the device includes a stand-up unit with ijycKoBoE, one-on-one impulses of control of a symmetric thyristor I, based on Transistor 6, peaHcyropOB 7 10, capacitor 11 and transformer 12, the output winding of which is loaded on a resistor 13, diode 14 and control switch symmetric rosette Echo 5, stable source constant vnogo current through the ballast capacitor 15, vpf mlgepnogo bridge 16, the resist ballast pa 17, 18 and zener diode 19 and SGPA. capacitor 20, posistors 21 and 22, resistor 23, additional ashfayuy diode 24, alarm sensor based on capacitors 25, 26 and 27, the signal from the midpoint of which is fed through the expander 28 and the resistor 29 to the base of the transistor 30 connected by an emitter and the collector of the parallel zener diodes 18 and 19, the electrodes of the gatep 31. The device for protection of the three-phase electric motor from working in emergency situations works as follows. When the start button 1 is pressed, the power supply is flowed around the current; When a technological nepei-ruzknn occurs, the motivation of the pointers mounted in the frontal parts of the motor winding increases sharply, Daod 24 becomes open, and the generation of the blocking gene is broken. This leads to the closing of the symmetrical thyristor 5, the locking of the coil 3 and the disconnection of the electrolyzer 31 from the set. If an asymmetrical mode occurs during a phase failure, a protective motor is switched off at the midpoint of the capacitor® 25, 26 and 27, which enters through the center of the capacitor 25, 26 and 27. the bridge and the limiting resistor 29 on the base of the transistor ZO, Last Off; it is short-circuited and thus breaks the generation of the generator. Switching off the electrical installation during its normal operation is carried out by pressing button 2, In the device, pozstory, mounted in the frontal part of the windings of the stat-. The motor is detached from the amplifiers with the help of a secondary lock-up diode 24, which is opened only when the electric-arc of the bodies is overheated due to an increase in the resistance of the posistors connected to the Hbnvi with the resistor 23. This increases the lump of the device. The use of amplifiers of alternating current in the form of a boking generator also allows a significant

Claims (1)

Claim A device for protecting a three-phase electric motor from emergency operation, containing a magnetic starter, the coil of which is connected to the mains phases through a 'Stop * button and the Start * button, disconnected by a 15 triac, connected to a mains phase, a stabilized power supply, resistors superimposed on the motor winding. · the asymmetric mode sensor in the condenser star is 20 tsrov connected to the supply wires, and the sensor output through the rectifier bridge is connected to the emitter-base transition of the transistor as a threshold element, the output which, 25 as well as the output of the posistors, are functionally connected to the control transistor transition, characterized in that, in order to increase noise immunity and reduce power consumption, it is additionally equipped with a biaoking generator with a pulse frequency of at least two orders of magnitude higher than the supply frequency network, to the input of which through a diode is connected a common point of the divider, consisting of a resistor and two posistors, connected in series with each other and connected to the output of a stabilized power source to which is also connected the emitter and collector of the transistor, sometimes a trace element.