Misalai Induction Cup Relay?

Mi ce Induction Cup Relay?

Induction Cup Relay

Relayin daɗin ya shi wani abu na induction disc relay. Induction cup relays ta yi aiki da haka da induction disc relays. Bayanin fanni na relayin daɗin yana dacewa da induction motor tare da labari ko takwas. Yadda labarin kungiyar daɗin ke gaba kan an fara cikin relayin daɗin. Tushen ya bayyana cewa relayin daɗin yana da labari biyu ko takwas.

Idan discin induction relay yana zama aluminum cup, inertia na juna ta fitowa. Wannan fitowa ta inganta tsawon inda induction cup relay ya yi aiki a matsayin mafi tsawo da induction disc relay. Amma, tushen projected pole system ta kammala don in ba da maximum torque per VA input.

A cikin unit biyu na labari, eddy current da aka samu saboda abubuwa biyu na poles, yana zama kadan suka fi girman abubuwa biyu na poles. Wannan ya ba da, torque per VA na relayin daɗin yana da kadan da takwas miliya masu C-shaped electromagnet. Idan magnetic saturation na poles za a iya rage da cutar, operational characteristics na relayin daɗin zai iya samun linearity da accuracy a matsayin kadan daɗin.

Principle of Operation of Induction Cup Relay

Daga baya, principle of operation na induction cup relay, shine da haka da induction motor. A rotating magnetic field ta samu ne saboda abubuwa biyu na field poles. A cikin design biyu na labari, abubuwa biyu na poles suna samu ne daga sama current transformer’s secondary, amma phase difference between the currents of two pole pairs is 90 deg; wannan ta samu ne saboda in taka inductor a series with coil of one pole pair, and by inserting a resistor a series with coil of another pole pair.

A rotating magnetic field ta induce current a aluminum brum ko cup. Daga baya, cewa principle of operation na induction motor, cup ta bazu ne a matsayin direction na rotating magnetic field, tare da speed mafi tsawo da speed na rotating magnetic field. 

Aluminum cup ta kasa hair spring: A normal condition, restoring torque na spring yana da mafi tsawo da deflecting torque na cup. Saboda haka, babu movement na cup. Amma, a faulty condition, current through the coil yana da mafi tsawo, saboda haka, deflecting torque produced in the cup yana da mafi tsawo da restoring torque na spring, saboda haka cup ta bazu ne kamar rotor na induction motor. Contacts attached to the moving of the cup to specific angle of rotation.

Construction of Induction Cup Relay

Magnetic system na relayin daɗin ta yi amfani da circular cut steel sheets. Magnetic poles ta project a inner edges na laminated sheets.Field coils ta wind a laminated poles. Field coil of 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 ta provided inside the cup or drum to strengthen the magnetic field cutting the cup.

Induction Cup Directional or Power Relay

Induction cup relays suna da muhimmanci a directional or phase comparison units. Sun ba da steady, non-vibrating torque and have minimal parasitic torques due to current or voltage alone.

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

The vector diagram of 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. The 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 of 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.

The relays which are such designed, that, they produce maximum torque at θ = 0, is P induction cup power relay.The 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.