Cascade speed regulation device under fast overcurrent protection of composite chopped wave band

Abstract

The invention relates to a cascade speed regulation device under the fast overcurrent protection of a composite chopped wave band. According to the invention, a digital signal processor is adopted for carrying out digital double closed loop control on a chopper subjected to internal feedback chopped wave cascade speed regulation. The chopper is controlled by misphase to reduce direct-current current pulse, and the performance and the reliability of the chopper are improved. Meanwhile, the traditional active inverter is modified, the upper bridge arm of the active inverter is composed of a full-control device IGBT(Insulated Gate Bipolar Transistor); the lower bridge arm of the active invertr is also composed of a half-control device thyristor SCR (Silicon Controlled Rectifier); therefore, overcurrent protection can be quickly carried out; and the problem that the thyristor is inverted and subverted when the system power grid is powered down can be effectively prevented. Therefore, the chopper subjected to the internal feedback chopped wave cascade speed regulation is subjected to digital double closed loop control by a new power electronic technology and a new topological structure and control method to jointly act on the cascade speed regulation, and a cascade speed regulation system is lifted to a new step on the technology.

Description

technical field [0001] The invention relates to a cascaded speed regulating device, in particular to a cascaded speed regulating device with composite chopper and fast overcurrent protection. Background technique [0002] my country is a country with a very short supply of power resources. As an important technical policy, energy conservation has a profound impact on the development of the national economy. Fans and water pumps are widely used in various sectors of the national economy, widely distributed, and consume huge amounts of electricity. According to statistics, the power consumption of fans and water pumps in the country accounts for more than 40% of the electricity consumption of the entire industry, and fans and water pumps generally need to perform load regulation during operation, and the corresponding flow rate must also be tracked and adjusted. The traditional adjustment method is to adjust the valve opening of the inlet or outlet, so that 30%-40% of the ele...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at the problems of low power factor and large harmonic content of current cascade speed control devices, and proposes a cascade speed control device with composite chopping and fast overcurrent protection, which has the advantages of small chopping current pulsation, speed regulation Features of stable, fast over-current and power-down fault protection

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