چیه ڕێگەکەی Induction Cup Relay?

Induction Cup Relay yê çi ye?

Induction Cup Relay

Ev relay di vêrsiyon eke induction disc relay ye. Induction cup relays wekhe induction disc relays şeşeyên ji bo şeşkirina derbas dixwazin. Bina bêhêrî ya wê relay di taybetmendiyên wekî motor ê induction da ku hewce dikare an jêr hewce bêyî. Hejmarên polan di relay de yên parastina li ser agahiyên windings nêzîk dibêjin. Wêne wanek ji polan paşêr a wergera induction cup relay.

Ji kerema xwe ji dema ku disk ê induction disc relay hatine biguheztin ji aluminum cup, inertiya sistemê rojhilatê zêde hatiye kêm kirin. Inertiya mekanîkî ya bi tevahî kêmere induction cup relay digehaz bike ye ku hêsan her gotarê induction disc relay bikat. Her du, sistemê projected pole design kirin ta max torq per VA input bidin.

Di unit ê four-pole de, ku di misalimizda de were nîşan kirin, eddy current û curdikê di cup de ji ber yek pair ê polan, tuşte pairê din polan re direk pirsin. Ev îro torq per VA ya wê relay ya hêsan sê her çend induction disc type relay bi C-shaped electromagnet. Ji kerema xwe divê magnetic saturation ê polan bejiyene ji bo designing, operating characteristics ê relay linear û rast bikin ji bo range ê wide ê operation.

Çeşeyên Çalakîya Induction Cup Relay

Wek ku ew amedîk, çeşeyên çalakîya induction cup relay, wekhe induction motor. Rotating magnetic field di navbera different pairs ê field poles de pêş de. Di four-poles design de hemû pairan ê poles ji secondary ê same current transformer nehatin destnusen, betir phase difference di currents de ê two pole pairs 90 deg re; Ev kar bi inserting an inductor in series with coil of one pole pair, and by inserting a resistor in series with coil of another pole pair.

Rotating magnetic field induced current di aluminum brum or cup de. Wek çeşeyên çalakîya induction motor, cup destpêketin ji roja rotating magnetic field, bi speed slightly less than the speed ê rotating magnetic field. 

Aluminum cup is attached with a hair spring : Di normal condition de restoring torque ê spring higher than deflecting torque ê cup. So there is no movement ê cup. But during faulty condition ê system, the current through the coil is quite high, hence, deflecting torque produced in the cup is much higher than restoring torque ê spring, hence the cup start rotating as rotor ê induction motor. The contacts attached to the moving of the cup to specific angle ê rotation.

Bina bêhêrîya Induction Cup Relay

Magnetic system ê relay built using circular cut steel sheets. Magnetic poles are projected on the inner edges ê these laminated sheets.The field coils are wound on these laminated poles. Field coil ê two opposite facing poles are connected in series.

Aluminum cup or drum, fitted on a laminated iron core is carried by a spindle whose ends fit in jeweled cups or bearings. Laminated magnetic field is provided on inside the cup or drum to strengthen the magnetic field cutting the cup.

Induction Cup Directional or Power Relay

Induction cup relays very suitable for directional or phase comparison units. They provide steady, non-vibrating torque and have minimal parasitic torques due to current or voltage alone.

In induction cup directional or power relay, coils ê one pair ê poles are connected across voltage source, and coils ê another pair ê poles are connected with current source ê the system. Hence, flux produced by one pair ê poles is proportional to voltage and flux produced by another pair ê poles is proportional to electric current.

Vector diagram ê this relay can be represented as follows,

Here, in the vector diagram, the angle between system voltage V and current I is θThe flux produced due to current I is φ1 which is in phase with I. Flux produced due to voltage V, is φ2 which is in quadrature with V.Hence, angle between φ1 and φ2 is (90o – θ).Therefore, if torque produced by these two fluxes is Td.Where, K is constant ê proportionality.

Here in this equation we have assumed that, flux produced by voltage coil lags 90 ^o behind its voltage. By designing this angle can be made to approach any value and a torque equation T = KVIcos (θ – φ) obtained where θ is angle between V and I. Accordingly, induction cup relays can be designed to produce maximum torque when the angle θ = 0 or 30o, 45o or 60o.

Relays which are such designed, that, they produce maximum torque at θ = 0, is P induction cup power relay.Relays produce maximum torque when θ = 45o or 60o, are used as directional protection relay.

Reactance and MHO type Induction Cup Relay

By manipulating the current voltage coil arrangements and the relative phase displacement angles between the various fluxes, induction cup relay can be made to measure either pure reactance or admittance. Such characteristics are discussed in greater detail in a session on electromagnetic distance relay.