Electrical MachineryExternal characteristics and voltage change rate of a transformerVoltage change rate:indicating the stability of power supply voltage.1.External characteristics and voltage change rateLoad coefficient External characteristic 1.External characteristics and voltage change rateWhen rared voltage is applied to the primary side and power factor of load cos2 is certain,the variation relation between the secondary voltage U2 and load current I2:U2=f（I2）.U20U20I2(leading)(lagging)THANKS FOR WATCHING!