Microcomputer protection device and signal filtering method of high-voltage motor

Abstract

The invention discloses a microcomputer protection device of a high-voltage motor. The microcomputer protection device a DSP controller and an upper computer; the input ends of the DSP controller are connected with a power source module, a human-computer communication module, an information transmission module, an analog quantity acquisition module and a switching quantity acquisition circuit; the analog quantity acquisition module comprises a three-phase protection current transformer, a three-phase protection voltage transformer, a zero sequence current transformer and an A / D conversion module; and the output end of the DSP controller is connected with a switching quantity output circuit. The invention also discloses a signal filtering method of a high-voltage motor. The microcomputer protection device of the high-voltage motor of the invention has the advantages of structural simplicity, reasonable design, operational easiness, high practicability, good use results and easiness in popularization, and can assist in avoiding the occurrence of malignant accidents caused by the failure of the high-voltage motor during the normal operation of a power grid. According to the microcomputer protection device of the high-voltage motor, an improved Fourier algorithm is adopted to filter signals received by the DSP controller, so that the accuracy of the signals can be improved, and therefore, the stability and safety of an entire power system can be improved.

Description

technical field [0001] The invention belongs to the technical field of high-voltage motor protection, and in particular relates to a high-voltage motor microcomputer protection device and a signal filtering method. Background technique [0002] As the most widely used power equipment in mechanical, electronic, electrical and other systems, high-voltage motors play a pivotal role in the national economy. With the continuous growth of the national economy, its demand is also increasing. According to statistics, since 1983, the annual output of electric motors in my country has increased at a rate of more than 10% per year. The high-voltage motor is also the main load of the power system. According to statistics, 90% of the electric energy in the power supply system is consumed by the motor. Since various abnormal working states and faults may occur during the operation of the power system, such as a sudden increase or decrease in voltage and frequency, or a sudden increase in...

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Problems solved by technology

Secondly, when the motor fails, the generated fault current and voltage signals are superimposed with attenuated non-periodic components and various high-frequency components on the basis of the fundamental wave, so the fault signal is not a periodic function

The main disadvantage of the Fourier algorithm is that it is easily affected by the attenuated DC component. In severe cases, the error can reach more than 10%.

The microcomputer protection system is a system that requires high precision. Errors in protection calculations can easily lead to misoperation of microcomputer protection devices, thereby affecting the stable and safe operation of the entire power system. Therefore, it is very important to eliminate or minimize errors

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