| Parameter | Symbol / Formula | Where |
|---|---|---|
| Primary EMF Equation of Single Phase Transformer (Ep) |  | f= frequency Np =Number of primary turns  = maximum flux |
| Secondary EMF Equation (Es) |  | f= frequency Ns =Number of secondary turns = maximum flux |
| Transformation ratio (K) |  | Ns =Number of secondary turns Np =Number of primary turns Vp =Primary voltage Vs =Secondary voltage |
| Turn Ratio |  | Ns =Number of secondary turns Np =Number of primary turns Vp =Primary voltage Vs =Secondary voltage |
| No load Primary Current (I0) |   | Im= Magnetising Component Iw=Active or Working or Iron loss component |
| Active or Working or Iron loss component (Iw) |  |  = Angle between Vp and I0 |
| Magnetising Component (Im) |  | = Angle between Vp and I0 |
| Impedance Ratio |    | Z2= Secondary Impedance Z1 = Primary Impedance |
Shifting in a Transformer (Referred to Primary) |      | R01= Equivalent resistance referred to primary X01= Equivalent reactance referred to primary Z01=Equivalent impedance referred to primary R2‘=Secondary resistance referred to primary X2‘=Secondary reactance referred to primary V2‘= Secondary voltage referred to primary I2‘= Secondary current referred to primary |
Shifting in a Transformer (Referred to Secondary) |      | R02= Equivalent resistance referred to secondary X02= Equivalent reactance referred to secondary Z02=Equivalent impedance referred to secondary R1‘=Primary resistance referred to secondary X1‘=Primary reactance referred to secondary V1‘= Primary voltage referred to secondary I1‘= Primary current referred to secondary |
| Percentage Voltage Regulation | 1)  2)  ***** (1) No. equation is generally used | Vnl= No load secondary voltage Vfl= Full load secondary voltage ****** Voltage regulation-down (Regdown): This happens when the secondary transformer terminal’s voltage output decreases due to a load attached to it. Voltage regulation-up (Regup): This occurs when the secondary terminal of the transformer experiences an increase in voltage upon removal of the load. |
| Voltage Regulation for lagging and leading | For lagging p.f Vnl – Vfl = I2R02cosφ2 + I2X02cosφ2 For lagging p.f Vnl – Vfl= I2R02cosφ2 -I2X02cosφ2 | R02= Equivalent resistance referred to secondary X02= Equivalent reactance referred to secondary |
| Power (Ideal Transformer) |  or  | ( P_p ) and ( P_s ) are the primary and secondary powers, ( V_p, V_s ) are the voltages, ( I_p, I_s ) are the currents. |
| Copper Loss (PCu) |  | Ip ,Is are the currents, Rp, Rs are the resistances of primary and secondary windings |
| Core Loss or Iron loss |  | Pi = Total core loss Ph = Hysteresis loss Pe =eddy current loss |
| Total losses in Transformer | Total losses = Pi +PCu = Constant Loss + Variable Loss | Pi = Total core loss or Constant loss PCu= Copper loss or Variable loss |
| Hysteresis loss (in watts) (Ph) |  | η = Steinmetz hysteresis coefficient (depends on the material) Bmax = Maximum flux density in the core f= Frequency of the magnetic field (in hertz) v= Volume of the core (in cubic meters) |
| Eddy current loss (in watts) (Pe) |  | ke = Constant that depends on the material’s resistivity and geometry Bmax = Maximum magnetic flux density (in teslas) f = Frequency of the magnetic field t = Thickness of the core laminations (in meters) v = Volume of the core (in cubic meters) |
| Efficiency (η) |   | Pout = Output power, Pin = Input power. |
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