High frequency inverter non-linear load starting control system

Abstract

The invention discloses a high frequency inverter non-linear load starting control system, comprising a power supply module, an inverter, an inverter current sampling device, a signal conversion device, a controller, a timer, a current limiting device and a non-linear load. The power supply module is used for supplying power to the system, and the power supply module is connected to the inverter; the inverter is connected to the input terminal of the inverter current sampling device, the output terminal of the controller and the current limitation device; the inverter current sampling device is used for sampling the output current and the voltage data of the inverter; the output terminal of the inverter current sampling device is connected to the input terminal of the signal conversion device; the signal conversion device is used for converting the simulation signal to the digital signal. The invention can perform protection on the circuit according to the load state, prevents the current from exceeding the protection threshold when the non-linear load is connected, and the inverter can start up the overload or short circuit protection. The invention is simple in structure and low in the cost.

Description

technical field [0001] The invention relates to the technical field of inverter control systems, in particular to a high-frequency inverter nonlinear load start-up control system. Background technique [0002] Because of its small size, high efficiency and price advantages, high-frequency inverters have become the mainstream in the civilian power supply market. High-frequency inverters first step up and rectify low-voltage direct current through a high-frequency transformer into a DC voltage of about 400V, and then invert it into 220V. Alternating current, this topology determines that the impact load capacity is not as good as that of the traditional power frequency inverter. The usual method is to increase the power capacity, or increase the electrical stress of the inverter bridge power tube to start the refrigerator or air conditioner, although in the short term It can run normally, but the long-term start-stop shock accelerates the aging of MOSFET, increases the failure...

AI Technical Summary

Problems solved by technology

[0002] Because of its small size, high efficiency and price advantages, high-frequency inverters have become the mainstream in the civilian power supply market. High-frequency inverters first step up and rectify low-voltage direct current through a high-frequency transformer into a DC voltage of about 400V, and then invert it into 220V. Alternating current, this topology determines that the impact load capacity is not as good as that of the traditional power frequency inverter. The usual method is to increase the power capacity, or increase the electrical stress of the inverter bridge power tube to start the refrigerator or air conditioner, although in the short term It can run normally, but the long-term start-stop shock accelerates the aging of MOSFET, increases the failure rate of the inverter, and increases the power capacity, which is not cost-effective in terms of cost. Some specific loads, such as non-linear equipment such as air conditioners or refrigerators, At the moment of starting, its current is 5-12 times of the rated current. Once it is in normal operation, the current quickly drops back to the normal level. Generally, the inverter has overload and short circuit protection functions. When starting these loads, the output current suddenly increases. It will trigger the protection, cause the inverter to alarm and stop, and the load cannot be started. Therefore, in some applications with impact loads, such as air conditioners and refrigerators, users choose power frequency inverters whose price efficiency is not dominant

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