Medium Voltage, High Power Applications

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.

In today’s society when we think of an electrician we think of a cable guy. People don 't look into the depth of things, electricians are very essential to our lives. Your life would feel incomplete without lights, radios, television, or not being able to drive a car. An electrician is a licensed technician that maintains the wiring in you school, homes, car or any place that functions off of electricity. Preservation of electric systems for homes and organizations is a key role of an electrician. Without running electricity a lot of the things that we rely on won’t be available. Electricity controls things such as your heat, television, washing machine, or anything that is powered by receptacles. In

Many of these conventional DC–DC converters have the disadvantages of operating at high duty-cycle, high switch voltage stress and high diode peak current. The conventional boost high step-up converter can provide very high voltage gain without operating at high duty-cycle by employing a coupled inductor, a switched capacitor and an additional diode. Non-isolated high step up converter overcomes this drawback. This converter reduces voltage stress on switch and diode by using additional one capacitor and rearranging components in conventional single switch high step-up converter. At the same time, the switch voltage stress is reduced greatly, which is helpful to reduce the conduction losses by using low power rated components and efficiency will increase. Single switch is used in the non-isolated high step up converter, thus reduce the entire cost of the converter. This non-isolated high step-up converter is used in many applications such as renewable energy system using low voltage energy sources such as fuel cells, solar panels,

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

Abstract —A novel interleaved dual buck full-bridge three-level inverter (IDBFTI) is proposed for the grid-connected system

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.

Our world is powered by electricity; it surrounds us in every turn and every corner, powering our streetlights, our TVs, our hospitals, our homes, and our communities. Electricity is a form of energy that results from charged particles. There are many energy sources that can be converted into electricity, and that’s why it is suited for powering our society. We can generate electricity from burning fuels, energy of falling water, solar energy, and basically anything that has energy. Electricity is also easy to distribute, using transmission lines connecting the energy power station to homes, schools and so on. Atoms consist of electric charge, so electric charge is everywhere and the electric charge has an electric field. An electric field can only be created by a positive charge and destroyed by a negative charge(Brightstorm, 2010). According to Bob emery, owner of senior physics website, to generate electric power it requires motion between a magnetic field and a conductor. Attraction of a magnet is limited to certain boundaries this is called the magnetic field of a magnet (Makemegenius, 2013).

Fast charging is becoming the leading technology used to reenergize electric vehicles in 30 – 60 minutes. With the ownership of EVs doubling each year, the need to implement efficient, fast charging infrastructure is progressively increasing. There are two technical approaches to establish fast charging 1. via a high power, 3-phase AC connection from an AC charging post at the charging station to an on-board high power charger in the EV or 2. via a high power DC connection from a high power DC charger at the charging station directly to the terminals of the battery in the EV. In this section, we will review AC level 2, DC/AC level 3 charging stations to improve our knowledge and the design of our project.

Power electronic converters, especially DC/AC inverters have been extending their range of use in industrial application because they provide better system efficiency, reduced energy consumption and improved quality of power. The output voltage of inverter could be fixed or variable at a fixed or variable frequency and output waveforms are therefore made up of discrete values, producing fast transition rather than smooth ones [2]. The ability to

This thesis deals with the design and analysis of control system structures for electric drives equipped with permanent magnet synchronous machines (PMSM) in automotive application.With the increasing popularity of multi-level inverters, the room for improvement of the performance of voltage source inverters has continuously been tested for various applications. The rapid development of high switching frequency power electronics in the past decade leads towards wider application of voltage source inverters in AC power generation. Therefore, this prompts the need for a modulation technique with less total harmonic distortion, fewer switching losses, and wider linear modulation range.The present thesis highlights the comparison of the conventional two-level inverter and the three-level diode clamped inverters for the application in automotive industry.

Nowadays, because of the fast evolution of electronic device, The recent developments in permanent magnet materials, solid state devices and microelectronic have led to the appearance of a new energy efficient drives using permanent magnet brushless direct current motors (PMBLDCM).

There are numerous methods which are as follows like (SPWM) First Sinusoidal Pulse Width Modulation, (MCPWM)Second, Multi-Carrier Pulse Width Modulation and (SHE-PWM) and Selective Harmonic Elimination Pulse Width Modulation which are implemented for harmonic elimination specially in multilevel inverter. (MCPWM)Multi-Carrier Pulse Width Modulation strategies are widely used, because they can be easily implemented to low voltage modules. Normally MCPWM can be classified and categorized as Level Shifted PWM (LS-PWM) and Phase Shifted PWM (PS-PWM) methods. (LS-PWM) Level Shifted PWM are characterized into three which are Firstly ,Phase Disposition Technique (PD), secondly ,Phase Opposition Disposition Technique (POD) thirdly Alternative Phase Opposition Disposition Technique (APOD) [45] [46] [47].

Brushless DC (BLDC) motors are used for many low and medium power drives applications due to their high efficiency, high flux density per unit volume, low maintenance requirement, low EMI problems, high ruggedness and a range of speed control. The commutation in PMBLDCM is accomplished by solid state switches of a three phase voltage source inverter (VSI). There is a necessity of an improved power quality (PQ) as per the

IN RENEWABLE dc-supply systems, batteries area unit usually required to back-up power for electronic equipment. Their voltage levels are generally abundant under the dc-bus voltage. Bidirectional converters for charging/discharging the batteries area unit thus needed. For high-powered applications, bridge-type bidirectional converters have become a very important analysis topic over the past decade. For raising power level, a dual full-bridge configuration is sometimes adopted

This project has been carried out at the department of the electrical engineering at S.V.I.T. Vasad. It has been great opportunity to work with this project and get knowledge about this area of the power electronics.