1. IGBT module is mainly composed of what parts?
Answer:
There are mainly IGBT chip, Diode chip, DBC (insulating substrate), aluminum wire, silicone gel, electrode, shell composition. The following figure:
2. SHYSEMI IGBT types?
Answer:
According to the voltage is polarized: 600V, 1200V, 1700V
According to the current is polarized: 50A, 75A, 100A, 150A, 200A, 300A , 400A ......
3. What is the difference between SHYSEMI L, K and U type modules?
Answer:
- L series is a low loss fast series with low on-state voltage drop, suitable for switching frequency below 20KHz;
- K series is a standard series, in the middle, suitable for medium frequency, optimized for 15-25KHz switching frequency;
- U series is ultra-fast series with low switching loss, suitable for switching frequency above 20KHz.
4. When should we use 600V, 1200V, 1700V?
Answer:
Mainly depends on the bus voltage. After single-phase rectification about the bus is about 300V to consider redundancy generally choose 600V series; three-phase rectification bus is about 540V generally use 1200V series; some special purposes, such as locomotive traction, the bus voltage can be up to 700V or more, you need to use 1700V series.
5. SHYSEMI IGBT design area?
Answer:
Motor control, UPS: constant load, welding machine, wind power, solar power
6. What is the on-state voltage drop of SHENHUAYING modules?
Answer:
Our 1200V on-state voltage drop is about 1.8V for L series, 2.2V for K series, and 3.5V for U series, with a slight difference for equal electrodes.
7. What is hard switch and soft switch? Answer Please refer to Fig. 1 and Fig. 2:
The hard-switching voltage and current waveforms are shown in Figure 1
Figure 1: Hard switching process of power device
Software switching voltage and current waveforms as Figure 2
Figure 2 Power device soft switching process
As can be seen from Figure 1, hard-switching circuits, turn on and turn off the process of current and voltage waveforms have a superposition process, resulting in losses; as can be seen in Figure 2, soft switching means that in the turn-on and turn-off process, the voltage and current waveforms are almost non-overlapping, and thus, the loss of the turn-on and turn-off time is reduced to a very low.
8. IGBT switching loss and pass-state loss are how to calculate?
Answer:
Switching loss: Pswitch = (Eon + Eoff) - fswitch
Pass-state loss: Pcond = Vce - Ic - duty
9. such as Figure 3, the IGBT current waveform in the on-state process appears Ir what is the reason?
Answer:
The reason for the spike Ir in the conduction process of the IGBT module is the reverse recovery current in the reverse parallel continuity diode.
Figure 3 IGBT conduction
10. As shown in Figure 4, what is the reason for the appearance of Ur in the voltage waveform of an IGBT during the turn-off process?
Solution:
The reason for the occurrence of Ur during turn-off of the IGBT is due to the presence of stray inductance, V overshoot= Lstray , and Vce= V overshoot+V(DC)-Link . The stray inductance is due to the design of the structure from the capacitor to the IGBT module. The principle of the design to minimize stray inductance is that the positive and negative currents are close together and as parallel as possible.
Figure 4 IGBT Shutdown
11. gate resistance RG on the switching performance of the IGBT has what effect?
Answer:
Gate resistance RG affects the switching speed, rise time tr, and fall time tf of the IGBT. The larger RGis, the larger the switching loss is, but the smaller the di/dt is, which reduces the VCEovervoltage. The smaller RGis, the smaller the switching loss is, but the larger the di/dt is, the larger the VCE is. When selecting RG, a compromise should be made to optimize the switching loss and VCEspike to reach a reasonable value at the same time.