 DEPARTMENT OF ELECTRICAL POWER ENGINEERING COLLEGE OF ENGINEERING POWER ELECTRONICS Summary - Inverters TOPICS COVERED: DC TO DC CONVERTER Buck (Step Down) Converter   Boost (Step Up) Converter Designing DC-DC Converters PULSE WIDTH MODULATED INVERTERS •Introduction •Inverter Types • Performance Parameters Single Phase Inverter • Single Phase Half Bridge Inverter • Single Phase Full Bridge Inverter • Methods of Controlling Single Phase Inverter • Pulse-Width Modulation (PWM) Control Strategy •Sinusoidal Pulse Width Modulation (SPWM) Three Phase Inverter • Line-to-line Voltage Waveform • Line-to-neutral Voltages • Output Currents • Voltage Control of Three Phase Inverters Inverters The full bridge and half bridge converters can be used to produce an ac output from a dc input. A simple switching scheme produces a square wave voltage output, which has a Fourier series that contains the oldd harmonic frequencies of amplitudes: Vn = 4Vdc/ (nπ ) Amplitude and harmonic control can be implemented by allowing a zero-voltage interval of angle α at each end of a pulse, resulting in Fourier coefficients: Vn = (4Vdc/ nπ) (cos(nα )) Pulse width modulation (PWM) provides amplitude control of the fundamental output frequency. Although the harmonics have large amplitudes, they occur at high frequencies and are filtered easily. The six step inverter is the basic switching scheme for producing a three phase ac output from a dc source. A PWM switching scheme can be used with a three phase inverter to reduce THD of the load current with modest filtering. The circuit of three phase inverter is applied in speed control of induction motors by varying output frequency. Control strategies for converting dc to ac are: Single Phase Square wave inverter Amplitude and harmonic control PWM bipolar switching PWM unipolar switching Three Phase Six step inverter PWM three phase inverter     Summarized formula: Summarized formula for inverter in pdf file 