Method for measuring and calculating electrical quantities of safety and stability control device based on FPGA

Abstract

The invention discloses a method, which is used for measuring and calculating the electrical quantities of an electrical power line component based on an FPGA in real time to obtain effective three-phase voltage and current values, effective zero sequence voltage and current values, and the frequencies of all phases. The method comprises the following steps: firstly, receiving a sampling message of an IEC 61850-9-1 standard to acquire the current sampling value of each electrical quantity of the line component; performing FFT processing on the electrical quantities in the FPGA to obtain a real value and a virtual value of a fundamental component; and reading the real value and the virtual value out by a coordinate rotation digital computer (CORDIC) in the FPGA, calculating the effective three-phase voltage and current values, the effective zero voltage and current values, and current phase angles of three-phase voltage, and then calculating the frequency of each phase according to the phase angle by software. The method has the advantages of meeting the requirements of the complexity, high real-time property and high accuracy of the calculation of the electrical quantities when the safety and stability control device is switched in a plurality of lines in an intelligent power grid, and overcoming shortcomings in the conventional method.

Description

Technical field: [0001] The invention belongs to the field of electric power system automation, and is a method based on FPGA (Field-Programmable GateArray, Field Programmable Gate Array) to carry out real-time parallel calculation on the sampling value of electrical quantity measurement to obtain the effective value of voltage and current of three phases A, B and C, and the voltage The effective value of current zero-sequence component and the method of each phase frequency. It can meet the high real-time and high-precision requirements of the electrical quantity calculation of the safety and stability control device under the smart grid architecture. Background technique: [0002] In the traditional power grid security and stability control device, the hardware first conditions the output signal of the electromagnetic transformer, and then performs fixed-step sampling (usually 24 points per cycle) through the analog-to-digital conversion chip, and then in the software base...

AI Technical Summary

Problems solved by technology

Therefore, in practical applications, most of the dual-CPU work mode is adopted. One CPU is responsible for the data processing of optical fiber Ethernet sampling values, and the other CPU is responsible for electrical quantity calculation and fault judgment processing. This not only leads to increased unreliability factors, but also brings a The new problem, how to realize data communication between dual CPUs, solutions include: dual-port RAM communication, high-speed serial communication, etc. In fact, these not only increase the design cost, but also greatly increase the design complexity

In addition, since the output signal of the electronic transformer is a digital signal, the frequency cannot be accurately measured by the hardware "zero-crossing comparison method", and the safety and stability control device has high requirements for frequency measurement, and the accuracy requires 0.01Hz

In fact, the calculation of software frequency measurement is more complicated, which further increases the burden on the CPU and makes it difficult to implement.

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