Voltage source inverter (VSI) fed induction motors are widely used in variable speed applications. The harmonic distortion in the line currents of the inverter depends on the switching frequency and the pulse width modulation (PWM) technique employed to switch the inverter. The inverter switching loss is also strongly influenced by the PWM technique used. This paper compares the harmonic distor...

Activation of T lymphocytes by pokeweed mitogen (PWM) is strictly monocyte (Mo)-dependent and results in T-cell mitogenesis and interleukin-2 (IL-2) secretion, coupled with an inability to utilize IL-2 due to an impaired expression of functional IL-2 receptor (IL-2R). Such IL-2R impairment could arise in PWM-activated T cells themselves or, alternatively, be the result of Mo-derived influences,...

The Flying Capacitor Multi Level Inverter (FCMLI) has a great advantage with respect to the availability of voltage redundancies. This work proposes a switching pattern for a modified inverter structure. It is used to improve the performance of chosen single phase five level H-bridge type FCMLI as compared to conventional FCMLI. The chosen multi level inverter is simulated for various multicarr...

In general Pulse width modulation (PWM) techniques of a voltage source inverter (VSI) need a sinusoidal reference signal and triangular carrier signal to generate the required modulating signals for the desired output. Modifications in modulating techniques can be considered in two ways, namely modified reference and modified carrier. The existing multilevel carrier based pulse width modulation...

This paper presents different types of bipolar Pulse Width Modulation (PWM) strategies for the chosen Cascaded MultiLevel Inverter (CMLI). The main purpose of MLI is to use power semiconductor devices of lower voltage ratings to realize high voltage levels at inverter output. Due to their ability to obtain refined output voltage waveforms, reduced Total Harmonic Distortion (THD) and reduced EMI...

Pulse-width modulation (PWM) is the basis for control in power electronics. The theoretically zero rise and fall time of an ideal PWM waveform represents a preferred way of driving modern semiconductor power devices. With the exception of some resonant converters, the vast majority of power electronic circuits are controlled by PWM signals of various forms. The rapid rising and falling edges en...

Renewable energy sources, especially solar photovoltaic systems (PV) are gaining popularity as the demand for electrical energy is increasing day by day. They can act as a voltage source feeding the power circuit. This work aims in utilising the PV system as a voltage source for a cascaded five level inverter. Further the performance of the PV panel fed cascaded multilevel inverter is analysed ...

This paper proposes a resonant dc link in PWM ac chopper. This can solve the spike problems and also reduce the switching loss. The configuration and PWM pattern of the proposed technique are presented. The simulation results are used to confirm the theory. Keywords—PWM ac chopper and Resonant dc link.

Pulse Width Modulated (PWM) solenoid valves can be used to control nozzle flow rates for precision spray applications reduce pesticide use, thereby reducing environmental risk and production cost. Field tests in a two-year-old young apple orchard were conducted investigate losses the ground air an air-blast sprayer equipped with three systems: 1) manually controlled constant-rate system enabled...

This paper discusses the design and implementation of single phase PWM inverter using 8051 microcontroller. The main features of 8051 based PWM inverter are simpler design, low cost, maximum range of voltage control and compact in size. The designed PWM inverter is tested on various AC loads like AC motor and intensity control of incandescent lamp in a closed loop environment.