1.1 the Role of Automatic Input Device for Backup Power Supply + 1.2 Basic Requirements of Automatic Input Device for Backup Power Supply + 1.3 the Charging Conditions of the Incoming Line BZT+ 1.4 the Discharging Conditions of the Incoming Line BZT+ 1.5 the Action Process of the Incoming Line BZT+ 2.1 Overview of Excitation System of Synchronous Generator + 2.2 Tasks of Generator Excitation Control System (I)+ 2.3 Tasks of Generator Excitation Control System (II)+ 2.4 Basic Requirements for the Excitation System+ 3.1 Reactive Power and System Voltage+ 3.2 Power System Voltage Regulation Measures+ 3.3 Power System Voltage Regulation Equipment+ 3.4 AVC, AVR and AGC+ 3.5 Automatic Voltage Control System+ 4.1 The Necessity of Frequency and Active Power Control in power system + 4.2 Overview of Frequency Characteristics of Power System+ 4.3 the Power-frequency Characteristic of Power System Load + 4.4 the Power-frequency Characteristic of Generator+ 4.5 Frequency Characteristic of Power System+ 4.6 the Working Principle of Automatic Low- frequency Load Shedding Device (I) + 4.7 the Working Principle of Automatic Low- frequency Load Shedding Device (II)+