A measurement synchronization method and system for a power electronic device

Abstract

The invention relates to a measurement synchronization method and system for power electronic equipment. The method comprises a data transmission method, a period variable sampling method, and a zero-crossing synchronization method. The system is composed of an AD data sampling module, an AD data receiving and storage module, an AD data packaging module, an AD data sending module, a power grid voltage data analysis module, a zero-crossing time calculating module, a synchronous signal sending unit, a phase-locked loop module, a real-time power grid frequency calculation module and a sampling period adjustment module. According to the solution scheme provided by the invention, the structure of the system is simple and novel and the system is suitable for a digital signal processing chip. The method is simple; application is flexible; and the system and the method can be realized conveniently. A power grid frequency can be tracked in real time; and an actual voltage value, an actual current value, and an actual reactive value can be calculated accurately under the circumstance that the power grid frequency fluctuation is large. The method and system have wide application range and can be applied to an FACTS device and can be applied to all pieces of power electronic equipment needing realization of functions of period variable sampling and zero-crossing synchronization.

Description

technical field [0001] The invention relates to a measurement synchronization method and system thereof, in particular to a measurement synchronization method and system of a power electronic device. Background technique [0002] The main features of the modern power system are: ultra-large capacity units, ultra-high voltage or even ultra-high voltage transmission, long-distance power transmission, large-scale AC-DC interconnection grid, high level of automation, market-oriented mechanism, etc. Worldwide, the imbalance of energy and economic development and the development of the electricity market have promoted the interconnection of large-scale power grids, and the interconnection of power grids has formed an increasingly large modern power system. The power system interconnection can realize the optimal utilization of resources in the largest geographical range, and give full play to the networking benefits of large power grid interconnection such as peak shifting and pea...

AI Technical Summary

Problems solved by technology

In an ideal power grid, the voltage and current measured by regular sampling are very accurate, but as long as the grid is polluted, especially after the frequency of the grid shifts, there will be errors in the effective values ​​of voltage and current calculated by regular sampling, and the overshoot of the grid voltage will cause errors. Zero will change or jitter, especially when the grid voltage harmonic pollution is serious, the calculated value and the actual value have a large deviation, which will lead to a large error when triggering the thyristor, and it is difficult to achieve the expected effect , there may be harmonic amplification in severe cases

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