The overcurrent fault of the inverter can be divided into short circuit, light load, heavy load, acceleration, deceleration, and constant speed overcurrent. When analyzing the reasons for the overcurrent fault of the inverter, two aspects should be considered: one is the external cause; the other is the inverter its own reasons.
VIEW MORE+In power semiconductor devices, MOSFETs play an important role in various power conversions, especially high-frequency power conversions, with high speed, low switching loss, and low driving loss. In the low-voltage field, MOSFET has no competitors, but as the withstand voltage of MOS increases, the on-resistance increases with the power of 2.4-2.6, and its growth rate makes MOSFET manufacturers and users have to reduce it by dozens of times. Rated current to compromise the contradiction between rated current, on-resistance and cost.
VIEW MORE+According to the equivalent circuit diagram of the IGBT, if a positive driving voltage is applied between the gate G and the emitter E of the IGBT, the MOSFET is turned on, so that the collector C and the base of the PNP transistor are in a low resistance state, which makes the The transistor is turned on; if the voltage between the gate and the emitter of the IGBT is 0V, the MOS is turned off, and the supply of the base current of the PNP transistor is cut off, so that the transistor is turned off. IGBT, like MOSFET, is also a voltage-controlled device. A DC voltage of more than ten V is applied between its gate G and emitter E. Only the leakage current at the uA level flows, and basically no power is consumed.
VIEW MORE+It is often encountered that the MOSFET on the power supply board cannot work normally. First of all, it is necessary to correctly test to determine whether the MOSFET fails. Then the key is to find the reason behind the failure and avoid making the same mistake again. This article has sorted out several common causes of MOSFET failure. and specific measures on how to avoid failure.
VIEW MORE+The MOS tube is a metal-oxide-semiconductor field effect transistor, or metal-insulator-semiconductor. The source and drain of the MOS tube can be reversed, and they are all N-type regions formed in the P-type backgate. In most cases, these two regions are the same, even if the two ends are reversed, it will not affect the performance of the device. Such devices are considered symmetrical. The bipolar transistor amplifies the small change of the current at the input end and outputs a large current change at the output end. The gain of a bipolar transistor is defined as the ratio of output to input current. Another type of transistor, called a FET, converts changes in input voltage into changes in output current.
VIEW MORE+Today, we will analyze five aspects: the efficiency and temperature rise of the motor, the insulation strength of the motor, the harmonic electromagnetic noise and vibration, the adaptability of the motor to frequent starting and braking, and the cooling problem at low speed. We explain the influence of the frequency converter on the motor.
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