A Novel Soft Switching Of Multi Level Dc Converter Fed Dc Motor Drive Using Pv Source

This chapter deals with the classification and basic operation of electric variable speed drive system and scope, merits and demerits of DC and AC drives. Then AC induction motor drive is selected for complete description. Here AC drive system is presented with its components like inverters, position sensors and current controller.

It is of great importance in our industries to cut the cost of power controlling with high efficiency and PWM satisfies this criteria. Therefore, it is

Switching power converters offer an easy way to regulate both the frequency and magnitude of the voltage and current applied to a motor shown in fig(1). As a result much higher efficiency and performance can be achieved by these motor drives with less generated noises[3].

Because of its linear characteristics and ease of controlling it's speed by simple power electronic circuit. The main obstacle for this type of system which has prompted the researchers to focus their studies toward AC machine, such as induction and synchronous machine. The availability of the variable speed drives for induction motor made it dominated in industry. Despite this, the small efficiency in induction motor especially those which have low power rating. The PMBDCM with predominant performance is found to be the solution for the drawbacks of the AC and Induction motors. The characteristics of the PMBDCM is similar to the separately excited DC motor, the difference in controller of PMBDCM which is the same of AC motor controller [2] [6].

D.C Motor is used for variable speed operation because in dc motor torque and flux that can be control independently and that is achieved by armature and field current control respectively. D.C motor has many advantages delivering high starting torque, ease of control and non linear performance. But due to certain disadvantage of dc machine such as mechanical commutator and brush holder required time to time maintenance [1] .So cost of the drive system is increases. But now D.C Motor is less used in industrial applications. Because of low cost, better performance and the requirement of maintenance is less as compared to D.C Motor it make the asynchronous motor advantageous in many industrial applications. SCIM are most widely used than all the rest of the electric motor as they have all the advantages of A.C Motors and are cheaper in cost as compared to slip ring induction motor. Because of absence of slip rings, brush maintenance duration and cost associated with the wear and tear of brush are minimized. Because of these advantages, the induction motor is used in element of most of the electrical drive system for all the conditions like starting, braking, change in speed and speed reversal. To achieve the maximum efficiency of the induction motor drive, so many techniques are developed in the last few years. Now a day’s high switching frequency converters are used for changing the frequency, phase and amplitude of the input to an A.C. Motor can be changed, hence the speed and motor torque can be controlled. With the help of power electronic it is possible to

In [34] authors has designed a new types of transformer less three-phase three-level NPC based power converter which performance has been analyzed in 2.64–4.16 kV DC, 5.1–12.8 kW. It’s performance like DC link voltage, efficiency & THD profile was acceptable. The authors assumed that this converter will be suitable for 15kV grid voltage. Converter switching circuit has been designed in SiC (Silicon Carbide) IGBT & Diodes as shown in Fig.18. So, this converter can be re-designed for medium or high voltage with SiC

To study the impact of VSFPWM on switching loss reduction over the entire modulation index range, the simulations were carried out different speeds (modulation indices) for a constant load torque. Table II and Table III compares the current ripple, and the percentage change in the current distortion and the switching losses for CSFSVPWM-VSFSVPWM and CSFDPWM2-VSFDPWM2 techniques respectively. Similar to the analytical results at section II, there is higher switching loss reduction capability at higher speed due to higher variation in current ripple at higher speeds (modulation indices). For example, with VSFSVPWM, around 15% switching loss reduction is obtained, whereas with VSFDPWM2, around 7.2% switching loss reduction is obtained. The difference in switching loss reduction capability in comparison to analytical results is attributed to the

Space Vector PWM (SVPWM) refers to a special switching sequence of the upper three power transistors of a three-phase power inverter. It has been shown to generate less harmonic distortion in the output voltages and or currents applied to the phases of an AC motor and to provide more efficient use of supply voltage compared with sinusoidal modulation technique. The biggest difference from other PWM methods is that the SVPWM uses a vector as a reference. This gives the advantage of a better overview of the system.

Common remarks on DC–AC–DC–AC Topologies: Topologies discussed from fig.4-6 have a high-frequency dc-ac inverter at the input side, which converts input dc into high-frequency AC. This high-frequency AC voltage level will be increased using HFT and then converted into dc by using a bridge

This paper is organized as follows: Section II describes the three phase BLDC motor and mathematical modeling of BLDC. Section III describes the four quadrant operation of the three phase BLDC motor and its features. The controller PI and its features are explained in Section IV. In section V, the simulation results are presented. Section VI concludes the proposed work.

The conventional two levels Inverter have many limitations for high voltage and high power application. Multilevel inverter becomes very popular for high voltage and high power application. The multilevel inverter is started with the three level converters. The elementary concept of a multilevel converter to achieve higher power to use a series of power semiconductor switches with several lower voltage dc source to perform the power conversion by synthesizing a staircase voltage waveform. However, the output voltage is smoother with a three level converter, in which the output voltage has three possible values. This results in smaller harmonics, but on the other hand it has more components and is more complex to control. In this paper, study of different three level inverter topologies and SPWM technique is explain and SPWM technique has been applied to formulate the switching pattern for three level and five level H-Bridge inverter that minimize the harmonic distortion at the inverter output. This paper deals with comparison of simulation results of three levels and five

to model the inverter switching strategies The PWM pulses was downloaded in FPGA(XC3S400PQ208) from Spartan 3. In addition to FPGA, Xilinx/modelsim software was used for simulation and verification of the proposed

Abstract: DC microgrid is the high quality electric power system focused on the development of renewable energy resources. The dc distribution system is connected to AC grid, Photovoltaic system and synchronous generator. Moreover, the power is transmitted through dc distribution line and is converted to required AC or DC voltages by load side converters. Those converters do not require transformers by choosing proper DC distribution voltage. The DC power line is 400V. This distributed design of load side converters also contributes to provide supplying high quality power. In this research, the configuration of DC microgrid system, control methods of distributed generation will be presented. Moreover, stand-alone system and grid connected system of DC microgrid will also be expressed. The model of DC microgrid system will be constructed with MATLAB/SIMULINK. Simulation results will be described.

Abstract: DC microgrid is the high quality electric power system focused on the development of renewable energy resources. The dc distribution system is connected to AC grid, Photovoltaic system and synchronous generator. Moreover, the power is transmitted through dc distribution line and is converted to required AC or DC voltages by load side converters. Those converters do not require transformers by choosing proper DC distribution voltage. The DC power line is 400V. This distributed design of load side converters also contributes to provide supplying high quality power. In this research, the configuration of DC microgrid system, control methods of distributed generation will be presented. Moreover, stand-alone system and grid connected system of DC microgrid will also be expressed. The model of DC microgrid system will be constructed with MATLAB/SIMULINK. Simulation results will be described.

Abstract— Multilevel inverter used in variable speed drive system is attracting more attention, due to various advantages that they offer when compared to standard 3-phase two level drives. For proper functioning of such systems pulse width modulation (PWM) strategy is of crucial importance. Control complexity of multilevel inverters increases rapidly with an increase in number of phases and the number of levels. The inherent low switching frequency in medium voltage industrial drive presents various challenges. Multilevel inverter topologies are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches, low harmonic contents and low electromagnetic interference