Nptel igbt pdf

It is a 16 bit high-performance digital signal controller DSC. DSC is a single chip embedded controller that integrates the controller attributes of a microcontroller with the computation and throughput capabilities of a DSP in a single core. A 1HP, 3-phase, V, 50Hz induction motor is used as load for the inverter. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

Karnataka, India. Related article at PubmedScholar Google. In the present time, in the most of the applications, AC machines are preferable over DC machines due to their simple and most robust construction without any mechanical commutators. Induction motors are the most widely used motors for appliances like industrial control, and automation; hence, they are often called the workhorse of the motion industry[6]. As far as the machine efficiency, robustness, reliability, durability, power factor, ripples, stable output voltage and torque are concerned, three- phase induction motor stands at the a top of the order.

Motor control is a significant, but often ignored portion of embedded applications. Motor control applications span everything from residential washing machines, fans to hand-held power tools, and automotive window lift, traction control systems and various industrial drives. All most in all the applications there is a drastic move away from analog motor control to precision digital control of motors using different processors.

Isolated Gate Drivers—What, Why, and How?

Digital control of induction motors results in much more efficient operation of the motor, resulting in longer life, lower power dissipation. Although various induction motor control techniques are in practice today, the most popular control technique is by generating variable frequency supply, which has constant voltage to ratio frequency ratio.

The system is designed as motor control system for driving 3-phase AC induction motor. The use of this 16 bit Digital Signal Controllers yields enhanced operations, fewer system components, lower system cost and increased efficiency[9].

The controller circuit essentially takes the reference speed and actual speed of the motor into account. The conventional approach of motor control is to first convert the line voltage into DC. The output voltage, frequency or both of inverter can be controlled by the application of power electronics and microcontroller. A closed loop control is normally required to satisfy the steady state and transient performance specifications of ac drives. The ability of varying any one of the above three quantities will provide methods of speed control of an induction motor.

The torque developed by the motor is directly proportional to the magnetic field produced by the stator. So, the voltage applied to the stator is directly proportional to the product of stator flux and angular velocity. This makes the flux produced by the stator proportional to the ratio of applied voltage and frequency of supply.

Therefore by varying the voltage and frequency by the same ratio, the torque can be kept constant throughout the speed range.

The below relations justify the above explanation. If we vary the voltage and frequency, keeping their ratio constant, then the torque produced by induction motor will remain constant for all the speed range.

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The voltage and frequency reaches the maximum value at the base speed [1]. We can drive the induction motor beyond the base speed. But by doing so only frequency varies but not voltage.ABB's website uses cookies. By staying here you are agreeing to our use of cookies. Learn more. Search now. There was a problem with your request. Please fill in required fields. Sign up. Electrical loads both generate and absorb reactive power. Since the transmitted load often varies considerably from one hour to the next, the reactive power balance in a grid varies as well.

This can result in unacceptable variations in voltage, including voltage depression or even voltage collapse. If required, switched or fixed air core reactors and capacitors can be used with the VSC as additional reactive power elements to achieve any desired range.

Installing a STATCOM at one or more suitable points in a grid will increase power transfer capability by enhancing voltage stability and maintaining a smooth voltage profile under different network conditions. Its ability to perform active filtering is also very useful for improvements in power quality. Physically, SVC Light can be considered a voltage source behind a reactance.

It is capable of yielding a high reactive power input to the grid more or less unimpeded by possible suppressed grid voltages, and with a high dynamic response. This is particularly useful, for instance, to support weak grids and to improve the performance of large wind farms under varying grid conditions, as well as of grids loaded by a large percentage of air conditioners in hot and humid climates.

For instance, for high speed rail systems and heavy industrial plants it is applied for voltage balancing of asymmetrical loads, mitigating voltage flicker created by electric arc furnaces, and active harmonic filtering. The multilevel chain-link solution is built up by linking H-bridge modules in series with one another to form the phase legs of the VSC.

For higher voltages, a step-down transformer is used to connect SVC Light to the grid. SVC Light provides a symmetrical operating range. For asymmetrical operations and in order to optimize performance, thyristor-switched reactors and capacitors are operated in parallel to form hybrid solutions.The bipolar power transistor is a three layer NPN or PNP device within the working range, the collector current IC is a function of the base current IB, a change in the base current giving a corresponding amplified change in the collector current for a given collector emitter voltage VCE.

The ratio of these two currents is of the order of 15 to Using the above circuit a set collector characteristic curves can be generated, that show how the collector current IC, varies with the collector to emitter voltage VCE for the specified values of base current IB.

For this condition both the emitter base junction and base collector junction are forward biased because the base is approximately at 0.

IB is through base emitter junction due to low impedance path and IC is zero. When both the junctions are forward bias and the transistor is in saturation region of its operation. Ideally when VCE exceeds 0.

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Once the base collector junction is reversed biased, IC levels off and remains essentially constant for a given value of Ib as VCE continue to increase.

Actually, IC increases very slightly as VCE increases due to widening of the base collector depletion region. This collector region is known as breakover region. If base current is zero, then collector current is very small leakage current, transistor under these conditions acts as open switch. If such amount of base current is supplied which drives the transistor into saturation state then the transistor acts as a closed switch.

In order to maintain control, the base current should be just sufficient to keep the device in saturation. At turn-ON initially; the base current should be high so as to give a fast turn on. Any change in collector current must be matched by a change in base current. At turn-off the base current should be reduced at a rate that collector current can follow so as to avoid secondary breakdown.

nptel igbt pdf

In the off-state, a small reverse IB is maintained to avoid serious collector current. The power loss in a transistor is a function of the product of collector emitter voltage and the collector current.

As a switch the power losses of transistor are small, because. To exploit the transistor fully without over heating during switching, safe operation area characteristics can be used.

When switching between the two states occurs, it is essential that voltage and current values must at all times during the switching period be within the rectangular area. The highest instantaneous power losses that can be tolerated being progressively restricted for longer switching times.

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The switching loss of transistor can be high because during the switching both the voltage across and current through the transistor can be high. A high switching frequency can mean the predominant loss is that due to switching.

The exact switching loss is a function of the load circuit parameters as well as the form of the base current change.

The current gain of a transistor can be improved if base drive current is obtained from another transistor this is known as Darlington arrangement.

FGPF4633 IGBT. Datasheet pdf. Equivalent

Main menu. Power Transistor Common Emitter Configuration Using the above circuit a set collector characteristic curves can be generated, that show how the collector current IC, varies with the collector to emitter voltage VCE for the specified values of base current IB. Open Switch: If base current is zero, then collector current is very small leakage current, transistor under these conditions acts as open switch. Close Switch: If such amount of base current is supplied which drives the transistor into saturation state then the transistor acts as a closed switch.

Transistor as Switch In order to maintain control, the base current should be just sufficient to keep the device in saturation. Power Losses in Power Transistor The power loss in a transistor is a function of the product of collector emitter voltage and the collector current.

As a switch the power losses of transistor are small, because In the open position leakage current is small In the close position the saturation voltage is small. Typical safe operation Area To exploit the transistor fully without over heating during switching, safe operation area characteristics can be used. Transistor Sage Operation Area When switching between the two states occurs, it is essential that voltage and current values must at all times during the switching period be within the rectangular area.Create an AI-powered research feed to stay up to date with new papers like this posted to ArXiv.

Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. Namboodiri and Harshal S. NamboodiriHarshal S.

nptel igbt pdf

Wani Published Computer Science. Inverter is basically an interface between DC source like photovoltaic cell and AC networks. There are many inverter topologies but output current distortion and efficiency are the two main parameters for the selection of inverters.

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Two such topologies are described herein. Save to Library. Create Alert. Launch Research Feed. Share This Paper. Figures and Topics from this paper. Citations Publications citing this paper. Seyezhai KrishnaP. MakhubeleKingsley A. References Publications referenced by this paper. SaadMat IsaC. Ismails. R mohd saadC. Bose Computer Science Draw the operational equivalent circuit of an IGBT and explain its operating principle in terms of the schematic construction and the operational equivalent circuit.

However, initial claims of infinite current gain for the power MOSFETs were diluted by the need to design the gate drive circuit capable of supplying the charging and discharging current of the device input capacitance. This is especially true in high frequency circuits where the power MOSFET is particularly valuable due to its inherently high switching speed. This is particularly true for higher voltage devices greater than about volts which restricted the use of MOSFETs to low voltage high frequency circuits eg.

With the discovery that power MOSFETs were not in a strong position to displace the BJT, many researches began to look at the possibility of combining these technologies to achieve a hybrid device which has a high input impedance and a low on state resistance.

nptel igbt pdf

However, this approach required the use of a high voltage power MOSFET with considerable current carrying capacity due to low current gain of the output transistor. Also, since no path for negative base current exists for the output transistor, its turn off time also tends to get somewhat larger.

An alternative hybrid approach was investigated at GE Research center where a MOS gate structures was used to trigger the latch up of a four layer thyristor. However, this device was also not a true replacement of a BJT since gate control was lost once the thyristor latched up.

Although p channel IGBTs are possible n channel devices are more common and will be the one discussed in this lesson. This layer forms a pn junction with the drain layer and injects minority carriers into it.

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The n type drain layer itself may have two different doping levels. The lightly doped nregion is called the drain drift region.

THREE PHASE INDUCTION MOTOR DRIVE USING IGBTs AND CONSTANT V/F METHOD

Doping level and width of this layer sets the forward blocking voltage determined by the reverse break down voltage of J2 of the device. However, it does not affect the on state voltage drop of the device due to conductivity modulation as discussed in connection with the power diode.

This construction of the device is called Punch Trough PT design. The PT construction does offer lower on state voltage drop compared to the NPT construction particularly for lower voltage rated devices.

However, it does so at the cost of lower reverse break down voltage for the device, since the reverse break down voltage of the junction J1 is small.

The doping level and physical geometry of the p type body region however, is considerably different from that of a MOSFET in order to defeat the latch up action of a parasitic thyristor embedded in the IGBT structure. A large number of basic cells as shown in Fig 7. Important resistances in the current flow path are also indicated. The base of the lower n-p-n transistor is shorted to the emitter by the emitter metallization. However, due to imperfect shorting, the exact equivalent circuit of the IGBT includes the body spreading resistance between the base and the emitter of the lower n-p-n transistor.

If the output current is large enough, the voltage drop across this resistance may forward bias the lower n-p-n transistor and initiate the latch up process of the p-n-p-n thyristor structure.With the advent of semiconductor devices, revolution is taking place in the power transmission distribution and utilization.

This course introduces the basic concepts of power semiconductor devices, converters and choppers and their analysis. Phase control technique — Single phase Line commutated converters — Mid point and Bridge connections — Half controlled converters with Resistive, RL loads and RLE load— Derivation of average load voltage and current — Active and Reactive power inputs to the converters without and with Free wheeling Diode —Numerical problems.

Fully controlled converters, Mid point and Bridge connections with Resistive, RL loads and RLE load— Derivation of average load voltage and current — Line commutated inverters -Active and Reactive power inputs to the converters without and with Free wheeling Diode, Effect of source inductance — Derivation of load voltage and current — Numerical problems. Three phase converters — Three pulse and six pulse converters — Mid point and bridge connections average load voltage With R and RL loads — Effect of Source inductance—Dual converters both single phase and three phase — Waveforms —Numerical Problems.

Inverters — Single phase inverter — Basic series inverter — Basic parallel Capacitor inverter bridge inverter — Waveforms — Simple forced commutation circuits for bridge inverters — Mc Murray and Mc Murray — Bedford inverters — Voltage control techniques for inverters Pulse width modulation techniques — Numerical problems. Follow us on Facebook and Support us with your Like. Average rating 4. Vote count: No votes so far! Be the first to rate this post.

Your email address will not be published. Table of Contents. How useful was this post? Click on a star to rate it! Leave this field empty.Login Now. In this region, MOSFET behaves like an open switch and is thus used when they are required to function as electronic switches.

Having known this, let us now analyze the biasing conditions at which these regions are experienced for each kind of MOSFET. This is because under this state, the device will be void of channel which will be connecting the drain and the source terminals. This is because, only then the channel will be formed to connect the drain terminal of the device with its source terminal. This is because, when done so, these devices will be deprived of their p-type channel, which further drives the MOSFETs into their cut-off region of operation.

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