Matrix Converter An Introduction

Variable-speed motor drive that uses an AC Drive has enjoyed widespread use because of its great energy-saving effect. What is yet unsolved are the suppression of a power harmonic current and the effective use of regenerative energy during deceleration. In order to fully solve these technical issues, we employ the Matrix converter technology, which directly converts from AC power source to AC output. Matrix Converter Basic Principle The matrix converter directly converts AC to AC rather than AC to DC to AC as in conventional voltage source PWM AC Drives. Matrix converters have capability to regenerate power and suppress input current harmonics and noticed as optimum drives for applications ranging from cranes, elevators and centrifuges where regeneration occurs, to air-conditioning fans and feed-water pumps where high harmonic countermeasures are required. Figure 1 shows main circuit configurations of the matrix converter and the conventional voltage source PWM AC Drive. The main circuit of the matrix converter consists of small input filters, which consist of reactors and capacitors, and 9 bi-directional switches. The bi-directional switches consist of the combination of IGBTs shown in Fig.1. On the other hand, the voltage source PWM AC Drive consists of a power AC Drive circuit with the combination of a rectifying circuit on the input side, a smoothing circuit with capacitors on the intermediate part, and IGBTs on the output side. Matrix Converter Voltage source PWM AC Drive

Fig.1 Main circuit configurations of matrix converter and voltage source PWM AC Drive PWM method The matrix converter directly PWM switches 3-phase AC power supply voltage and outputs any given voltage and frequency. Figure 2 shows an example of switching waveform of the matrix converter. Zone 1 of Fig.1 shows that the switching is made from phase-T voltage which is the standard, through phase S which is the intermediate voltage phase, to phase R which is the highest voltage phase. This allows smaller voltage fluctuation than as in conventional AC Drives and therefore suppresses surge voltage and leakage current. PWM waveform example

Fig.2 PWM waveform example Input current control The matrix converter uses electric potential at all the three input phases to PWM switch. Therefore, output voltage and input current can be controlled at the same time. Matrix converters hold two advantages; its energy-saving regeneration and high harmonics suppression effect by controlling a current. Figure 3 shows I/O waveforms of a conventional AC Drive and the matrix converter.

Fig.3 I/O waveforms of conventional AC Drive and matrix converter Figure 4 shows the comparison of input current harmonics. The input current of the matrix converter is almost sine wave and problems associated with harmonics can be easily solved by the matrix converter alone.

Fig.4 Comparison of input current harmonics Effects of matrix converters Matrix converter circuits offer the following effects comparing to conventional AC Drive circuits. Suppression of power harmonics Realizes less than 7% THD of input current and more than 98% input power factor without any specific measures taken. Longer operating life The main circuit does not have endurable parts such as an electrolytic capacitor. This makes the operating life of the main circuit longer and the maintenance interval longer. Elimination of derating With the elimination of current constriction on any specific device, the reduced operation during low-frequency operation is unnecessary. Power regeneration Unique bi-directional switches for directly connecting the power supply and loads enable continuous regeneration. High-efficiency Only the bi-directional switches are used to connect the power supply and loads, allowing higher-efficient operation than as in conventional AC Drives.

THREE PHASE MATRIX CONVERTER DESIGN

How to write a Technical/Engineering project report: Need assistance?

Useful guidelines for M.Tech. & B. Tech. Students Main Idea, Thesis Statement, Topic Sentences Have you ever been really excited about a movie? I mean so excited you go to the theater, get popcorn and other snacks, and sit down waiting for an hour and a half of wonderful cinema bliss? Then it happens - it's an hour and a half later and you realize you have no idea what you just watched! Even when you try to explain it to people, the words escape you. The most you can say is that it had no plot and it made no sense. It's a terrible experience when you watch a movie with no plot, and reading an essay with no main idea, no thesis, and no cohesive points tying it all together is no less aggravating of an experience. The best way to avoid such a tragedy in your own writing is to get great at setting the stage for your writing. Main Idea The first place to start is with your main idea. The main idea is the key concept being expressed or examined. Putting this in our movie frame of reference, the main idea would be the broad context on what the movie is about, or the genre in which the movie will be viewed. Is it a romantic comedy about high school sweethearts? Maybe it's a historical drama about the Battle of Waterloo or the sinking of the Titanic. The main idea is the overall gist of what the piece will be dealing with as a whole. Thesis Statements Okay, so now that we have the main idea, we need to prepare ourselves to clearly explain it to our audience, the reader. What we need is a thesis statement! A thesis statement is a one- or two-sentence condensation of your argument or analysis that will follow in your writing. The thesis statement is our narrowing of our overall main idea. Moving along with our movie idea, let's say our main idea is a romantic comedy about two high school sweethearts. While that helps narrow things a bit from the entire genre of romantic comedy, it doesn't really help give us the detail we need to truly understand what is unique about our movie. However, I can add the thesis statement of Two high school sweethearts ready to embark on the wonderful world of college. Will they follow their dreams and end up at separate colleges, or follow their heart to the same school? Now we can better understand what this movie is about! Topic Sentence Of course, there is a bit more narrowing that can be done in this process. Sometimes space does not allow us to give a longer explanation. Sometimes people really need us to get to the point quickly. This is where our topic sentence comes into play. A topic sentence is generally at the beginning of the opening paragraph and gives a one-sentence summary of the main point. Think of the topic sentence as our movie blurb that everyone grabs a hold of. It's that bit of information the producers want us to hold onto that will allow us to build excitement for the movie and remember with ease the main point of the film. Require further assistance for writing a Technical report? Contact at tyagiagam@gmail.com

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M.Tech. MATLAB/SIMULINK project List 2: Power Electronics, Power System, Renewable Energy based projects

M. Tech. Project List 2015 Branch: Power System Engineering, Power Electronics, Renewable Energy List 2: i. Analysis of PWM based voltage source inverter for adjustable speed drive applications. Pulse Width Modulation variable speed drives are increasingly applied in many new industrial applications that require superior performance. Recently, developments in power electronics and semiconductor technology have lead improvements in power electronic systems. Hence, different circuit configurations namely multilevel inverters have become popular and considerable interest by researcher are given on them. Variable voltage and frequency supply to AC drives is invariably obtained from a three-phase voltage source inverter. Simulation results are obtained using MATLAB/Simulink environment for effectiveness of the study. ii. Analysis and design of grid connected PMSG based Wind Energy power plant Modeling and simulation of a grid connected wind-driven electricity generation system has been done. The power conversion unit features a wind-turbine-driven PMSG, a diode rectifier, and a dc/ac inverter. The Permanent Magnet Synchronous Generator (PMSG) offers better performance than other generators because of its higher efficiency and of less maintenance since they don’t have rotor current and can be used without a gearbox, which also implies a reduction of the weight of the nacelle and a reduction of costs. Therefore, in this paper the modeling and control of a PMSG is presented. All the components of the wind turbine and the grid-side converter are developed and implemented in MATLAB/Simulink. iii. Hysteresis based control of grid connected PV inverter This paper describes the Grid Connected Solar Photovoltaic (PV) system Using Hysteresis Current Control Inverter to supplies electric power to the utility grid and is one of the major renewable energy sources. In this paper we are going to develop a complete computer simulation program of a grid connected solar PV system in distribution power network using MATLAB/Simulink and SIM Power System tool. This paper aims to grid-connected solar PV system at steady state and also to study their transient responses to changing inputs. These control method provides robust current regulation, achieve unity power factor, low THD and optimize the PV energy extraction suitable for grid connected PV systems Contact:+91-9557069448, tyagiagam@gmail.com

Three Phase flying capacitor inverter

Power Quality problems (Sag/Sweel, Harmonics, Undervolatge/Overvoltage, spikes etc ) and their removal new control system

Harmonics and reactive power regulation and guidelines are upcoming issues and increasingly being adopted in distributed power system and industries. Vital use of power electronic appliances has made power management smart, flexible and efficient. But side by side they are leading to power pollution due to injection of current and voltage harmonics. Harmonic pollution creates problems in the integrated power systems. The researchers and engineers have started giving effort to apply harmonic regulations through guidelines of IEEE 519-1992. Very soon customers have to pay and avail the facility for high performance, high efficiency, energy saving, reliable, and compact power electronics technology. It is expected that the continuous efforts by power electronics researchers and engineers will make it possible to absorb the increased cost for solving the harmonic pollution. The thyristor controlled reactors of various network configurations are widely used in industries and utility systems for harmonic mitigation and dynamic power factor correction. These thyristor controlled reactor operate as a variable reactance in both the inductive and capacitive domains. By means these two parameters two types of problems are normally encountered. The first problem is the reactive power (Var) that leads to poor power factor and the harmonics appears due to presence of power converter devices and nonlinear loads for example, electrics machines, fluctuating industrial loads, such as electric arc furnaces, rolling mills, power converters etc. These types of heavy industrial loads are normally concentrated in one plant and served from one network terminal, and therefore, can be handled best by a local compensator connected to the same terminal. A simulink model of power system with all these power defeciencies is constructed and contrl system is applied to check the results as follows: