Monthly Archives: November 2015

Usage of IGBT in CNC Machines

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The simple definition of plasma cutting is cutting steel and other metals of different thicknesses (or sometimes other materials) using a plasma torch. When doing this, an inactive gas (in some cases, compressed air) is turned into plasma by blowing it at extreme speed out of a nozzle; at the same time an electrical arc is forged through that gas from the nozzle to the metal being cut. The plasma is sufficiently heated to melt the metal in the process of cutting.

 

The Insulated Gate Bipolar Transistor (IGBT) versus the Metal Oxide Semiconductor Field Effect Transistor (MOSFET) has been a controversial subject ever since the IGBT technology came into being in the 1980’s. CNC plasma cutting machines were initially using MOSFETs as transistor. But the usage of IGBTs (Insulated Gate Bipolar Transistor) is now grown notably in this field. IGBTs are deployed in plasma cutting technology to provide more commercial plasma cutting equipment. With assimilated MOSFETs, if one of the transistors actuates out of time, it can cause collapse of one quarter of the inverter. A later discovery, IGBTs, is not as subject to this failure mode. IGBT technology for welding applications has certainly proved to more effectively handle the rigorous demands the high duty cycle welders as it offers higher voltage capacities and heat tolerances than the earlier MOSFET.

 

CNC machines with IGBTs are swift. Preheating is not needed, so the torch can start cutting without delay. With speeds up to 500 IPM, it can contend with laser cutters based on the type of part. These cutters are multipurpose, competent for piercing, complicated cutting and beveling in one process. These can effectively cut any electrically conductive metal up to 6″ thick. Accurate cutting is one of the characteristics of CNC plasma cutters. These machines are paired with highly advanced software and high precision components; the want for costly secondary operations is dispelled. The torch head is computer controlled and can do clean, sharp cuts. Solid integration between the cutting torch and software results in excellent manufacture, high cut quality, fewer dross and high superiority edges. An IGBT based CNC engine may appear complicated, the CNC (computer numerically controlled) software takes most of the guess work out of cutting. With an ultra modern package, even a first time worker is doughty of creating amazing outcome. The machines are safe too, almost all systems offer a downdraft or exhaust system to pull out the smoke away from the operator.

 

The IGBT plasma cutters are better suited for professional environments. These take up a different method to start the pilot arc. Many IGBT plasma metal cutters often deploy high frequency starting technology, high voltage circuit just for the starting process while others use Pilot Arc starting technology, where the torch enables a constant arc without touching the workpiece.

 

CNC plasma cutting sector has been improved notably in recent years. In the past, CNC machine’s cutting tables were horizontal, but nowadays vertical CNC plasma cutting machines are available providing enhanced flexibility, swift operation and utmost safety.

IGBT and it’s Use in X-Ray Machines

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The role of X-ray machines is indispensable in the field of medical diagnostics. Electromagnetic radiations with a wavelength of 0.1 to 100 angstroms are called.X-rays. Hard X-rays with wavelengths of 0.1 to 1 angstroms have penetration abilities that make them competent for producing images of the inner parts of human bodies. Today X-rays are usually generated by using the X-ray tube developed by William Coolidge, although X-rays were first discovered by Wilhelm Roentgen in 1895. In the Coolidge tube, a high voltage is used to accelerate electrons emitted from a filament to gain high energy. The electron beam is guided to a target, usually tungsten, to excite the X-rays. The X-ray machine power supply must operate at very high voltages (20-150 kV) while supplying sufficient current to generate the X-ray beam needed to produce images.

 

The input AC voltage is corrected and fed to a high-frequency PWM resonant inverter that is based upon IGBTs. This allows using a high-frequency transformer to create the very high voltages needed for the X-ray tube operation while keeping the size and weight small. The output of the high-frequency transformer is rectified to generate the desired DC voltage for the X-ray tube. The dynamic response of the X-ray power supply must be fast and its DC output voltage must reach steady-state in a short time to prevent noise and defects in the X-ray image. These requirements can be met by using an IGBT based PWM resonant inverter.

 

A 48kW resonated converter involves four power modules, per module contains two paralleled IGBTs and antiparallel diodes. They are arranged in a half-bridge or push-pull configuration depending on the input, at 400Vac or 200Vac. At highest power, peak load current is 550A at 50 kHz, or 275A per module for 48kW out. The generator is zero-voltage switched to create a continuous series resonant output current that’s transformer-isolated —stepped up and rectified to the desired output level. The output voltage is regulated by a DSP-based frequency-modulated controller, with dual loop feedback on resonant current and load kV.

 

For an extent of output power, the system operates from 48 kHz up to 68 kHz with a resonant LC shunt across the load transformer. With fundamental series resonance at 48 kHz, the shunt resonates at 68 kHz. At low frequencies, the generator operates close to resonance, with high power throughput. As frequency rises, the impedance increases —the load being shorted by the resonant shunt. The power is zero at 68 kHz.

 

Least size is significant for ultra-modern X-ray equipments. In this variant of the converter, the four ZVS modules with their compactly packed IGBT and FRED chips need just ¼ of the surface area previously used. Consolidation and separation of the drivers, and ZVS logic circuitry farther curtail the footprint. Mechanical integrity & noise immunity are improved because control signals have less distance to travel.

 

Founded in 2001, at Houston in Texas, Young & New Century LLC has been supplying IGBT power transistor modules. We have a team for Quality Control like no other. This means that we know properly about what to do in order to make sure that the quality of all the parts we’re selling is high. We sell new and original electronic parts only with a warranty period of 30 days. Our stock is carefully handled and held to the utmost standards, and housed in a regulable environment warehousing facility. Our company is specialist in selling electronic components of different manufacturers for a complete extent of your industrial applications. Please take a look at our website http://www.uscomponent.com. You can send us a Request For Quote (RFQ) anytime via this website for the part you need. You can send your RFQ via an email also to Sales@uscomponent.com.

Story of Integrated Circuits

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Integrated circuits (ICs) are considered as a foundation of present-day electronics. They are the cornerstones of most circuits. These are the omnipresent tiny black “chips” which come into view on just about every circuit board. If you are not some kind of insane, analog electronics wizard, perhaps you will have at least one IC in each electronics project you set up, so it is vital to understand them, inside and out.

 

A collection of electronic components like capacitors, resistors, transistors- all crammed into a small chip, and linked with each other to attain a common goal is called an IC. These come in various sorts and varieties: single-circuit logic gates, voltage regulators, microcontrollers, op amps, microprocessors, 555 timers, motor controllers, FPGAs… the list does not end.

 

We can visualize the tiny black chips by thinking about integrated circuits. But what does the black box contain? The actual “substance” to an integrated circuit is a complicated layer of semiconductor wafers, copper, and other materials, which interlinks to create resistors, transistors and various components in a circuit. The trimmed and well-formed amalgamation of these wafers is known as die.

 

The integrated chip itself is small and because of this the wafers of semiconductor and layers of copper it consists of are extremely thin. The interconnections between the layers are immensely complex. A die of an integrated chip is the circuit in its tiniest allowable form, too tiny to solder or connect to. The die is packaged, which makes our job of connecting to the IC effortless. The IC package turns the delicate, tiny die, into the black chip we’re all familiar with. The small and delicate die is turned into the black chip (which is familiar to all) by the IC package.

 

The integrated circuit die is encapsulated by the package and this package splays the die out into a device we can more conveniently connect to. Every outward connection on the die is linked via a small piece of gold wire to a pad or pin on the package. Pins are the silver, releasing terminals on an IC, which go on to attach to other parts of a circuit. Pins are what will go on to connect to the rest of the components and wires in a circuit. For this reason, these are most important to us.

 

There are numerous varieties of packages. Each of them has distinctive dimensions, mounting-types, and/or pin-counts. Majority of them are DIP, QDIP, SQP, PDIP, SOP, QFP, PLCC, SW, SQL, DPAK, SIP, SOS, TSOP, FDIP, TO3, TO2205, SOT23, SOT223, PENTAWATT and many more.

 

Each pin of an IC is unique in the cases of both location and function and all ICS are polarized. This means the package has to have some way to convey which pin is which. Maximum ICs use either a dot or a notch to specify which pin is the first pin. (Sometimes both, sometimes one or the other).

 

Once you know where the first pin is, the remaining pin numbers increase sequentially as you move counter-clockwise around the chip.

Usage of IGBT in Electric and Hybrid Vehicles

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The rapidly-growing and diversified automotive industry is the largest in the world because of an extensive range in customer preferences for comfort, design and technology. At present, for commuting, transportation of merchandise, recreation and shopping purposes, gasoline powered cars are still preferred in our society. But we all know it well that gasoline powered vehicles provoke acute environmental pollution during the time of consuming declining fossil fuel provision. Expansion of hybrid-electric and electric vehicles is a resolution to this problem. The worldwide goals to reduce fuel depletion & emissions, with pioneering attempts in developing electric vehicles (EVs) and hybrid electric vehicles (HEVs), bring significant technological challenges.

 

The IGBT (Insulated Gate Bipolar Transistor) has a vital influence on the transportation sector in all over the world. It allowed the introduction of dependable & cost effective electronic ignitions systems that have enhanced gasoline fuel efficacy by at least 10 percent. They have also been major elements in the improvement of mass transit systems and the deployment of electric and hybrid electric vehicles.

 

IGBT is playing the prime role in the new era of hybrid and electric vehicles. All hybrid-electric and electric cars that have been introduced into the market so far have relied upon IGBT-based motor drives. In new powertrain generations such as EVs and HEVs, IGBTs play the key role in order to drive the electric motor or store the energy. IGBTs run at very high frequencies and under high power which makes them vulnerable to thermal problems. Thermal characterization helps to optimize the IGBTs layout, structure and mounting to optimize its performance.

 

Mass transit systems within cities must depend on buses, trams, and underground trains. To lessen urban pollution, gasoline powered buses are being replaced with electric buses in many cities. All of these below requirements were met by using the IGBT-based motor drive in control system for the electric transit bus: (a) wide range of speed including high operating speed; (b) large startup torque for good acceleration; (c) high efficiency; and (d) regenerative braking to increase utilization of batteries. In Europe and Japan, electric tram transit systems have been modernized by using IGBT-based motor drives. According to AEG-Westinghouse Transport Systeme, Germany, the low floor concept is becoming a standard customer prerequisite. This has been enabled by today’s IGBT modules.

 

After all we can say, the availability of IGBTs has been diametrical to the advancement of the hybrid vehicles and to the expansion of the charging substructure for the electric vehicles. IGBTs will carry on playing a significant part in the availableness of expense reducing technology for the whole hybrid and electric vehicle business.

 

Being established in Houston, TX, Young & New Century LLC has been selling IGBT power transistor modules since 2001. We are specialist in selling electronic components of various manufacturers for entire extent of your commercial & industrial applications. Please take a look at our official website www.uscomponent.com. You can send us a Request For Quote (RFQ) for your required part via this website. You can send your RFQ via an email also to Sales@uscomponent.com.

IGBT and its Usage in Motor Control

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The IGBT, Insulated Gate Bipolar Transistor, is a switching transistor that is driven by voltage applied to the gate terminal. Device structure and operation are identical to those of an Insulated Gate Field Effect Transistor, generally known as a MOSFET. The primary dissimilarity between the two device types is that the IGBT uses conductivity modulation to reduce on-state conduction losses which MOSFET does not do.

 

IGBT is a device that integrates the voltage feature of a bipolar transistor (collector – emitter) and the drive feature of a MOSFET. The key reason behind the flourishing popularity of IGBT is its superiority at high speed switching applications. This device is well-known for integrating high efficiency and fast switching. It is mainly used as an electronic switch in many modern appliances: variable-frequency drives (VFDs), electric cars, trains, variable speed refrigerators, air-conditioners and even stereo systems with switching amplifiers. Today we will discuss about usage of IGBT in motor control.

 

Advancements of highly capable motor drives are very essential for industrial applications. Satisfactory dynamic speed command tracking and load regulating response are two must needs, for a high performance motor drive system. DC motors excel in terms of speed control for acceleration and deceleration. The power supply of a DC motor joins right away to the field of the motor which approves for accurate voltage control, and is required for pace and torque control applications. Because of their simpleness, ease of application, dependability and auspicious cost, DC drives have long been a mainstay of industrial applications. Because of low horsepower ratings, DC drives are usually less costly in comparison with AC drive systems. DC motors are being used as adjustable speed machines traditionally and an extensive extent of options has developed for this intention.

 

To obtain sufficient levels of power handling capability, especially in motor control applications those demand multiple drive elements, power integrated circuits have been developed using hybrid constructions of the distinct transistors. Hybrid techniques have been necessary and useful due to the power handling limitations of monolithic power integrated circuit technology. Power integrated circuit design has often been limited by the absence of power packages that provide the low thermal impedance and high performance switching necessary for reliable operation. The switching elements of these modules, which may be Insulated Gate Bipolar Transistors (IGBTs) or various forms of thyristors, “chop” low-frequency (e.g., 60 Hz or dc) voltages /currents at the input / output port into high-frequency square wave pulses of variable width (20 to 200 ms).

 

The silicon GTO was the only available power semiconductor switching device until the 1990s. It had power conducting ability compatible for motor control applications. The ratings of IGBTs had adequately developed in the 1990s. It overcame one Megawatt which allowed entrance of the IGBT into the traction market. The availableness of the IGBT made allowance for notable advancements in the motor drive technology due to exclusion of snubber circuits and an raise in the operating frequency of the inverter circuit employed to transfer power to the motors.

IGBTs and Solar Inverters

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IGBTs are excellent choices for use in solar inverters where voltage from a solar panel array on a residential or commercial building is converted from direct current to alternating current at a specific voltage output and frequency. IGBTs, like MOSFETS, use voltage rather than current as a means of control, with current applied across their gates being typically very low.

 

IGBTs are a type of bipolar junction transistor or BJT which have a semiconductor gate structure composed of metal oxide. BJTs have a higher current capability compared to MOSFETs. The speed at which an IGBT turns off is determined by how rapid the minority carrier recombines. The turn off time has an inverse relationship with the voltage drop or VCEON. This means that IGBTs with inherently rapid turn off times have a higher voltage drop and vice versa. Ultra fast IGBTs do switch off much faster than standard IGBTs, even if the IGBTs have the same dimensions and are basically manufactured the same way. The exact combination of speed and voltage drop is determined by adjusting the minority carrier recombination rate this in turn controls the turn off time.

 

Four switches are typically employed in a solar inverter. Two of the switches are high side IGBTs, while the other two are low side IGBTs. Solar inverters of this type produce a sinusoidal wave form and single phase alternating current. The frequency and voltage depend on the specific use required. In a household solar array system, the inverter will normally deliver voltage and frequency similar or the same as that provided by the mains electricity provider as it will be used to power household appliances that are designed to use mains power.

 

Inverters for installation in a residential capacity are usually linked to the power grid. These installations usually provide power to the grid when there is a surplus with tariff benefits depending on the location and provider. To enable this feature, the solar inverter is required to pulse width modulate the IGBTs above 20kHZ. The modulation frequency is normally around 50 to 60 Hz. This sort of pulse width modulation means that the two outut indicators can be maintained relatively small in size and they will also have the benefit of suppressing harmonics effectively.

 

This sort of solar inverter has switching speeds much higher than can be heard by the human ear so they remain basically noiseless.

 

To keep the power dissipation as low as possible, pulse width modulation is restricted to the two high side IGBTs while the low side IGBTs are commutated at 50 to 60kHz.

Integrated Gate Bipolar Transistors (IGBT) Performance Reaches New Levels

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IGBTs (Integrated Gate Bipolar Transistors) have now been around for 30 years or so and have played a very useful role in their capacity as a key component in power switches, particularly at high voltages. However, the use of IGBTs has been eclipsed somewhat by power MOSFETs for applications where the switching frequency is at the high end of the power spectrum – greater than 100 kHz. However, that has now changed. IGBT research and development has come up with improvements in IGBT design which mean that these components are now able to handle the frequency range and temperatures which are being demanded by more and more applications.

 

The new IGBT design is an extremely thin IGBT, fabricated on a wafer structure, which is reported to have a blocking voltage of 650 volts. It is designed for DC to DC conversions of up to 200 kHz. These ultra rapid operating IGBTs are now more than a match for their competitors in the high end semiconductor market.

 

The superiority of SJ MOSFETS challenged by new version IGBTs

 

Up to the recent development phase of these ultra thin wafer IGBTs, superjunction (SJ) MOSFETS have been the semiconductor of choice for those applications requiring tolerance to both high temperature and high switching frequency. SJ MOSFETS have actually had a better performance record for these sorts of applications than conventional power MOSFETS as well as IGBTs which have lagged behind in performance. The new IGBT design is touted as matching the performance level of SJ MOSFETS in terms of switching capacity but the main advantage is that the manufacturing process is simpler, making these components much more competitively priced compared to their competitors. Another comparison between the new IGBTs and SJ MOSFETS gives the IGBTs a clear lead in terms of their Tjmax, which is 175oC, compared to that of the SJ MOSFETS at 150oC.

 

IGBT structure improvements

 

The key improvement of these IGBTs is their fabrication process. They are fabricated on an extremely thin wafer of around 70μm using a punch through structure. This design permits the components to incorporate a collector which is only lightly doped. This means that they have less stored charge and consequently much improved switching performance – as has already been mentioned. They are rated up to 200 kHz, which is a doubling of the performance of their predecessors.

 

One of the inherent problems inherent in older style IGBTs was the fact that electron irradiation or metal doping was used to enhance switching speed. The design has the in-built problem that as the operating temperature increases, the current tends to leak. This limitation has meant that IGBT have had a limited usage role when the Tjmax has been above anything like 150oC. The improvements in design have meant that temperatures up to 175oC and beyond are now tolerated.

 

At this temperature the leakage of current is very much reduced compared to older style GBT designs. The new style IGBTs have a noticeably higher cell density which has a knock on effect on various other component properties. The lower voltage drop also accompanies a smaller gate capacitance. This combination means that the minimal internal gate resistance still means that the components are capable of the reported doubling of switching speed.

What Is IGBT Based Power Inverters?

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IGBTs or integrated gate bipolar transistors are the component of choice where high switching speeds and high voltage are required in a device such as a power inverter. Inverters convert direct current to alternating current at a specific voltage and frequency. Power converters can be of very small size – mobile phones have miniature power converters in their circuits – but may be of much larger size and deal with hundreds of mega watts of power. In a power converter, the voltage and current typically control the overall power rating, whereas in an electronic device, these two parameters carry the signal or information in the device.

 

Power inverters work with the help of a component such as an IGBT or a MOSFET or BJT. These are all switching devices that turn the power on or off at a specific speed and voltage range. In some applications, commutated thyristors are used rather than semiconductors.

 

The best type of power inverter should have a sinusoidal waveform, but in practice most are not sinusoidal and they tend to contain a specific set of harmonics.

 

Low and medium power inverters can use a non sinusoidal waveform, such as a square or semi- square waveform, and perform quite satisfactorily, but when the voltage increases, sinusoidal waveform inverters are to be preferred. Power inverters with adjustable alternating current frequency capacity can be designed by using control circuitry which varies the turn on and turn off ties of the IGBTs or other switching components in the circuitry. The switching method of these high speed power semiconductor devices can determine the harmonics of the resulting output voltage.

 

The input into the power inverter is typically a rectifier producing DC if the application is an industrial one, but the initial voltage may be coming from a variety of different sources, including fuel cells, solar cells or even a battery. The rectifier involves a DC link. The network frequency is at first rectified and then finally inverted back to AC at an adjustable frequency. This sort of rectification can be achieved by using thyristor converter circuits or standard diodes. The inversion itself is carried out by standard circuitry.

 

An example of a typical power inverter in which the switching components are IGBTs is a single phase Unipolar inverter. This type of inverter typically consists of a bridge form with four IGBTs which are bidirectional. In this example, the circuit’s input voltage is in the region of 220V which is being fed in by the rectifier unit. The AC output is achieved by triggering the four IGBTs in a prescribed sequence. Two of the IGBTs are at first switched on by triggering the IGBT gates. Current flows from the positive side of the IGBTs to the negative. The second half of the cycle reverses the direction of the current.

Characteristics of Integrated Gate Bipolar Transistor (IGBT)

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IGBTs or integrated gate bipolar transistors to give them their full name are semiconductor components with highly specific uses. They are similar in a way to power transistors but have significant differences in the way they are controlled. Power transistors are controlled by the amount of current flowing across their base in contrast to IGBTs which are controlled by the voltage applied to their gate. The characteristics of the IGBT make them more of a combination of a power transistor and a MOSFET (metal-oxide semiconductor field effect transistor).

 

The IGBT is most commonly used in applications where high frequency power switching is needed. One of the reasons why the IGBT works well for this purpose is that only a tiny amount of current is needed applied to its gate. The current is only very small because of high impedance at the control gate. IGNTs are not only able to be switched much more rapidly than other types of semiconductor but they also have other desirable characteristics, especially the fact that they can be used at high voltages.

 

High power, high frequency devices work by turning the current on and off rapidly with the help of a switching device. Apart from IGBTs, other switching components include MOSFETS and bipolar transistors. An oscillating device is used to control the IGBT or other type of switch.

 

One common application of IGBTs is in a high voltage electric motor. The voltage used by the motor is converted from DC to AC with the IGBT controlling the frequency at which the AC is provided. There are three different types of motors which may have IGBTs incorporated into their control device. These are,

 

A three phase induction type motor

A three phase brushless motor with sinusoidal BEMF

A three phase brushless motor with trapezoidal BEMF

 

The motor drive may be either of a sinewave or squarewave type. Sinewaves are preferred where RF interference might be a nuisance, although squarewave drives are actually the more efficient of the two. Of the three motor types, the first one, the induction motor tends to have a sinewave type drive, although there are high and low pulses in any wave phase noticeable.

 

The other two types of motor use magnets instead of rotors that are found in induction motors. These motor types are somewhat more expensive than induction motors, but more efficient. The main difference between the two types of brushless motor is the type of wave produced by their drives: some are trapezoidal, others are sinewave. In all these motors, there are three phases involved and six transistors. MOSFETs tend to be the preferred choice at lower voltages, say 200 volts or less, but for higher voltages, the IGBTs are preferred. IGBTs can handle voltages of up to 1200 volts.

Applications of IGBT

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Now-a-days the IGBT (Insulated Gate Bipolar Transistor) is extensively applied in the transportation, renewable power generation, consumer, aircraft, medical, industrial and financial sectors all worldwide. As a result, billions of people from around the globe are enjoying enhanced comfort, convenience, and quality of life. IGBTs are known for their fantastic efficiency and speedy switching characteristics. These qualities make IGBTs very suitable for applications where saving energy and protecting the environment are very important. IGBTs are being used in almost all sectors of our economy because there isn’t any exact alternative available which can be used in place IGBT and can offer same advantages.

 

Over the last 20 years, the cumulative influence of the advanced capability of IGBT-powered applications has been an aggregate worth savings of $ 2.7 Trillion for U.S. consumers and $ 15.8 Trillion for consumers all over the world. On the other hand, the developed efficiency generated by IGBT-powered applications has propagated a cumulative lessening in carbon dioxide emissions by 35 Trillion pounds in the United States and 78 Trillion pounds worldwide during the last 20 years. So, the IGBT has already had a key impact to make a sustainable world-wide society with advanced living standards along with alleviating the environmental impact.

 

After its conception in the early 1980s, the applications for IGBTs have been incessantly spreading. It has already had a great impact on: the transportation sector, the consumer sector, automation sector, industrial sector, medical sector, aerospace sector, marine sector, defense sector; financial sector, power transmission and distribution sector, renewable energy power generation sector and many other sectors of the economy.

 

What would happen if all the IGBT were removed from the applications that they serve today?” The answer is quite revealing: Our new solar and wind based renewable energy sources would not be able to deliver power to the grid because the inverters would stop functioning. Our gasoline power cars would stop running because the electronic ignition systems would no longer function. Our hybrid electric and electric cars would stop running because the inverters used to deliver power from the batteries to the motors would no longer function. Our electric mass-transit systems would come to a standstill because the inverters used to deliver power from the power-grid to the motors would no longer function. Our air-conditioning systems in homes and offices would stop working because the inverters used to deliver power from the utility company to the heat-pumps and compressors would no longer function. Our refrigerators and vending machines would no longer function making the delivery and storage of perishable products impossible. Our factories would come to a grinding halt because the numerical controls use to run the robots would cease to function. Our new low-energy compact fluorescent bulbs would stop functioning limiting our activities to the daytime. Our portable defibrillators recently deployed in emergency vehicles, on-board airplanes, and in office buildings would no longer be operational putting over 100,000 people at the risk of death from cardiac failure.

 

In one statement, the quality of life in our society would be greatly deteriorated if the IGBT is no longer available. It’s a blessing of modern science.