电力电子技术第5版王兆安英文Chapter10章节.ppt

Application of Power Electronics 10.1 DC motor drivers ( thyristor-DC motor system ) 10.2 Frequency converters and AC drivers 10.3 Uninterruptible Power Supply ( UPS ) 10.4 Switching Power Supply 10.5 Power factor correction (PFC) 10.6 Application in utility power system 10.7 Other applications 10.1 DC motor drivers ( Thyristor-DC motor system ) 10.1.1 Rectifier mode of operation 10.1.2 Inverter mode of operation 10.1.3 Reversible DC motor drive system (four-quadrant operation) 10.1.1 Rectifier mode of operation Speed-torque (mechanic) characteristic when load current is continuous Speed-torque (mechanic) characteristic when load current is discontinuous EMF at no load (taking 3-phase half-wave as example) For a ? 60o For a 60o Speed-torque (mechanic) characteristic when load current is discontinuous For different a The point of EMF at no load is raised up. The droop rate becomes steer. (softer than the continuous mode) 10.1.2 Inverter mode of operation Equations are just the same as in the rectifier mode of operation except that Ud, EM and n become negative. E.g., in 3-phase half-wave Or in another form 10.1.3 Reversible DC motor drive system(4-quadrant operation) 4-quadrant speed-torque characteristic of Reversible DC motor drive system 10.2 Frequency converters and  AC drivers Indirect AC to AC converters(AC-DC-AC converters) 10.2.1 Configurations of AC-DC-AC converters Configurations with one-direction power flow Configuration with regenerative energy dissipating circuit Braking transistor and braking resistor Configurations with regenerative power feedback through inversion-mode thyristor rectifier circuit Configurations realizing bi-directional power flow through double-sided PWM converters 10.2.2 Major Applications of AC-DC-AC  frequency converters (VVVF converters) Adjustable speed AC motor drives Advantages of AC motors over DC motors Energy saving on AC motors High-performance AC motor drives C