18-1

Chapter 18

Utility Interface

• Power quality has become an important issue

18-2

Various Loads Supplied by the Utility Source

• PCC is the point of common coupling

18-3

Diode-Rectifier Bridge

• Bock diagram

18-4

Typical Harmonics in the Input Current

• Single-phase diode-rectifier bridge

18-5

Harmonic Guidelines: IEEE 519

• commonly used for specifying limits on the input current distortion

18-6

Harmonic Guidelines: IEEE 519

• Limits on distortion in the input voltage supplied by the utility

18-7

Reducing the Input Current Distortion

• use of passive filters

18-8

Power-Factor-Correction (PFC) Circuit

• For meeting the harmonic guidelines

18-9

Power-Factor-Correction (PFC) Circuit Control

• generating the switch on/off signals

18-10

Power-Factor-Correction (PFC) Circuit

• Operation during each half-cycle

18-11

Thyristor Converters for 4-Quadrant Operation

• Two back-to-back connected 2-quadrant converters

18-12

Switch-Mode Converter Interface

• Bi-directional power flow; unity PF is possible

18-13

Switch-Mode Converter Interface

• Rectifier and Inverter modes based on the direction of power flow

18-14

Switch-Mode Converter Control

• DC bus voltage is maintained at the reference value

18-15

Switch-Mode Converter Interface

• Waveforms in the rectifier mode

18-16

3-Phase Switch-Mode Converter Interface

• Rectifier and Inverter modes based on the direction of power flow

18-17

EMI: Conducted Interefence

• Common and differential modes

18-18

Switching Waveforms

• Typical rise and fall times

18-19

Conducted EMI

• Various Standards

18-20

Conducted EMI

• Filter arrangement