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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Since the BJT has low conduction losses, and the MOSFET has faster switching speed with simple control circuits, it obviously would be desirable to have a device that combined the good points of each. In the late 1980 s, the insulated gate bipolar transistor (IGBT), which combines the best features of MOSFETs and BJTs, became commercially available. Schematic symbols for the insulated-gate bipolar transistor are shown in Figure 120.13. Like the BJT, it has a collector and emitter; however, instead of a base terminal, it has a gate, like the MOSFET. The IGBT is essentially a monolithic Darlington pair in which a MOSFET is used to control a BJT. The MOSFET gate, with its high input impedance, results in a low-power voltage control for the device with relatively fast switching times, although slower than a MOSFET. The BJT portion, which conducts the main current, provides lower conduction losses than a MOSFET. During the 1990 s, the IGBT became the device of choice for variable-speed AC motor drives up to several hundred horsepower. By the end of the 1990 s, IGBTs were pushing the lower limits of applications for GTOs, as higher blocking voltage ratings became available. IGBTs are now available with ratings up to 1200 amps at 3300 volts or 900 amps at 4500 volts.
Automotive Power Semiconductor Devices
Published in Ali Emadi, Handbook of Automotive Power Electronics and Motor Drives, 2017
The IGBT is a switching transistor controlled by voltage applied to the gate terminal. Device operation and structure are similar to that of a power MOSFET. The principal difference is that the IGBT relies on conductivity modulation to reduce on-state conduction losses. The IGBT has high input impedance and fast turn-on speed like a MOSFET, but exhibits an on-state voltage drop and current-carrying capability comparable to that of a bipolar transistor while switching much faster. IGBTs have a clear advantage over MOSFETs in high-voltage applications where conduction losses must be kept low. Although turn-on speeds are very fast, turn-off of the IGBT is slower than a MOSFET. The IGBT exhibits a current fall time or “tailing.” The tailing restricts the IGBT to operating at moderate frequencies (less than 50 kHz) in conventional PWM switching applications. Since most automotive motor drive applications operate within this frequency range, IGBTs easily outperform high-voltage MOSFETs and offer a 2–3 times reduction in silicon area and cost.
Switchable Diodes and Gated Transistors
Published in Muhammad H. Rashid, Ahmad Hemami, Electricity and Electronics for Renewable Energy Technology, 2017
An insulated gate bipolar transistor (IGBT) is a transistor similar to a BJT but with more and improved capabilities such as fast switching. It is now widely used in many switching devices and vastly used in power converters (particularly in wind turbines), as we discuss in Chapter 20. As the name implies, IGBT has a gate and the gate is insulated from the body. This allows high voltage and high current in the IGBT to be isolated from the control signal to the gate.
Design and Implementation of Digital Phase Locked Loop for Single-Phase Grid-Tied PV Inverters
Published in Electric Power Components and Systems, 2018
The IGBT module is a small and low power loss intelligent module; it is integrated with gate driving circuits and freewheeling diodes. The rating of each IGBT device is 15A/600V. Two aluminum electrolytic capacitors, each rated 300 µF/450V, were connected in parallel. One resistor with 10 KΩ was used across the capacitors to provide a discharge path for the energy in the capacitors when the circuit is switched off. A 3 mH common coupled inductor was employed at the output side of the PV inverter. Two ultra-rapid 5 A fuze was used to protect the inverter circuit. Differential amplifier circuit was built for measuring the grid voltage. Line current was measured by a current sensor ACS712 based circuit. For evaluating the performance of the developed digital PLL, a serial 12-bit DAC AD7568 converter (each of the converters was configured in voltage mode and provides an analog output that is proportional to the applied digital value) was employed to output the signals that was unable to be measured directly, such as the voltage components Vd, Vq in the rotating d-q frame, the estimated grid voltage phase angle θ and cos(θ). The values are treated in the range from –1 to 0 and 0 to +1 and will be displayed as 0 V, 2.5 V, and 5 V on the oscilloscope for the values of 0 –1, 0, and +1, respectively. The utility voltage is 240 V/50 Hz. The role of the variable single-phase transformer is to obtain a variable ac supply voltage to the PV inverter so that experiment tests can be carried out under relatively low voltage condition for safety reason.
Comparison of Offshore and Onshore Wind Systems with MPC Five-Level Converter under Energy 4.0
Published in Electric Power Components and Systems, 2018
Mafalda Seixas, Rui Melicio, Victor Mendes
An IGBT has physical limitations that have to be considered during not only design phase, but also on simulation studies. Particularly, the switching state of the IGBTs has to be made at a finite frequency. For instance, frequencies for the switching state of the IGBTs are reported to be in use as 2 kHz, 5 kHz or even 10 kHz. This physical limitation of the IGBTs implies that the control of the electric current will not be able to accurately follow the reference value and an error in the plane, , has to be accepted. The system slides along the sliding surface, , in order to assurance that the state trajectory nears the surface endorses the stability conditions [3], and [32] given by:
Lifetime prediction model for electric vehicle IGBT modules under driving conditions
Published in Journal of the Chinese Institute of Engineers, 2018
Ling-Ling Li, Peng-Chong Wang, Ching-Hsin Wang
The IGBT is a widely used power device, which consists of a metal oxide semiconductor field effect transistor (MOSFET) and bipolar transistor compound. Its input terminal is a MOSFET, and the output terminal is a PNP transistor. According to the composition, IGBT can be divided into horizontal and vertical categories. IGBT power module failure mode is divided into two categories: package failure and chip failure, in which package failure is the main failure mode. Overheating or heat-related problems are the main cause of IGBT package failure (Choi, Blaabjerg, and Lee 2015b). The typical structure of an IGBT module is multilayer. From top to bottom of the structure, the layers are, in order, IGBT chip, welding layer, copper layer, insulating ceramic layer, copper layer, welding layer, floor, and radiator. The special multilayer structure and the mismatch of thermal expansion coefficient between different materials cause fatigue and aging of the welding material under the influence of long-term thermal cycling, and eventually cause the device to fail due to chip lead break or temperature increase (Smet et al. 2011; Czerny et al. 2012; Pedersen et al. 2016; Tounsi et al. 2010; Yang, Agyakwa, and Johnson 2013). Therefore, it is necessary to establish the electrothermal model to evaluate the junction temperature of the power module and to predict the life expectancy with fatigue life theory.