A transistor is a semiconductor device used to amplify signals or act as an electrically controlled switch. A transistor is a three terminal device, a small current/voltage at one terminal (or lead) will control a large current between the other two terminals (leads). Transistors are essential components in almost all electronic circuits such as: amplifiers, switches, oscillators, voltage regulators, power supplies and most importantly digital logic ICs.
VIEW MORE+1. What is IGBT? IGBT is a new type of power electronic device. Its basic structure is to add an insulating layer and a control electrode between the base and emitter of the transistor. IGBT combines the advantages of MOSFET (Metal Oxide Semiconductor Field Effect Transistor), such as high input impedance, low drive power consumption, fast switching capability, etc., and the advantages of BJT (Bipolar Transistor), such as high current carrying capacity, low conduction voltage drop, etc. Therefore, IGBT has broad application prospects in the field of power electronics.
VIEW MORE+You may have three questions: What is an IGBT? What role does it play in the above devices? What's the difference between it and a seemingly tube?
VIEW MORE+SC 2 short-circuit fault waveform is shown in Fig.7. Once a short circuit occurs, the IGBT current rises rapidly, and the di/dt rise rate is determined by the bus voltage and the parasitic inductance of the loop. In the first stage, the IGBT begins to appear in an undersaturated state, and the IGBT collector voltage rises slightly during this process. However, due to the large Miller capacitance in this stage, due to the effect of dv/dt, some current will flow into the gate, resulting in a decrease in the gate voltage Vge. The increase of Vge will further cause the collector current to rise.
VIEW MORE+4. Short circuit fault SC 1 When the IGBT is turned on, it enters the short-circuit state, which can be analyzed with the double-pulse test circuit shown in Figure 3. By changing the size of the short-circuit inductance Lsc (within tens of nH), the turn-on and short-circuit behavior characteristics of the down-side IGBT can be analyzed. SC 1 is also the most common short-circuit fault of IGBT. According to the length of the desaturation time (depending on the short-circuit circuit noise), it can be further divided into a type I short circuit and a type II short circuit.
VIEW MORE+IGBT is one of the core components in the inverter, and its function is to convert direct current into alternating current. Therefore, the working reliability of the IGBT directly determines the performance stability of the inverter. Once there is a problem with the IGBT, it will cause the failure of the inverter, and even cause irreversible damage to the entire system. So how to detect whether the IGBT is good or bad?
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