Relay protection device based on 12-bit AD in SOC chip

Abstract

Aiming at problems that cost of a traditional relay protection device is high, acquisition precision is not high, measurement data is not complete and measured electric energy precision is low, the invention provides a relay protection device based on a 12-bit AD in a SOC chip. A technical scheme is characterized in that a power grid frequency is stored in a CPU module; the CPU module reads a frequency value and makes an acquisition frequency of an AD module which collects data in a period be consistent with a frequency of one period in a power grid; an ADC port in the AD module works under a multi-loop acquisition mode; a pulse counting method is used to accumulate electric energy and time 10ms is taken as a statistics period; an accumulation result is divided into two integers which are stored in an RAM; and one integer stores a pulse value and another integer stores an integer electrical degree. In the invention, a hardware circuit is simplified; under the condition that CT is measured, measured values of active power, reactive power, apparent power, a power factor and four-quadrant electric energy can be provided, and electric energy precision can reach a 0.5S grade.

Description

technical field [0001] The invention relates to a relay protection device, in particular to a relay protection device based on a 12-bit AD inside an SOC chip. Background technique [0002] At present, the commonly used design in the relay protection industry: DSP+MCU structure mode is adopted, and the DSP chip is responsible for controlling 6-channel synchronous AD sampling. If there are more circuits, 2 or 3 synchronous AD cascades are used to realize multi-channel (12, 18) AC signal acquisition; MCU is responsible for display, control, communication, logic control, etc. This technology has high cost, complicated hardware circuit, and cannot sample at high speed. The performance requirements of the supporting DSP chip are high, because the DSP collects a set of data chips to be interrupted once. This limitation cannot use high-speed data sampling. The weekly wave in the industry is generally 16 o'clock, 32 o'clock, and 48 o'clock, and the highest is 64 o'clock per week. P...

AI Technical Summary

Problems solved by technology

[0013] Aiming at the problems of high cost, low acquisition accuracy, incomplete measurement data, and inability to measure electric energy or low accuracy of electric energy measurement in traditional relay protection devices, the present invention provides a relay protection device based on 12-bit AD inside the SOC chip, It has the advantages of simple hardware, fast calculation speed, and high precision in calculating electric energy.

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