Data sampling time synchronizing and calibrating method and system thereof

Abstract

The invention discloses a data sampling time synchronizing method and a system thereof, wherein the method comprises the steps of calculating an actual sampling interval clock period number of a previous time synchronizing period, wherein the actual sampling interval clock period number comprises an integer part and a decimal part; in a current time synchronizing period, when a clock period signalarrives, respectively triggering the counting values of a first integer counter and a second integer counter to be added by one; when the counting value of the first integer counter is equal with thevalue of the integer part, triggering the counting value of a decimal counter to be added by the number of the decimal part; when the accumulated counting value of the decimal counter is higher thanor equal with a preset value, triggering the counting value of the second integer counter to be deducted by one; and when the counting value of the second integer counter is equal with the value of the integer part, transmitting a sampling pulse to a sampling controller, thereby controlling a sampling device to perform data sampling. The method and the system can improve time synchronizing precision of the sampled data through two integer counters and a decimal counter.

Description

technical field [0001] The invention belongs to the technical field of data sampling, and in particular relates to a time synchronization and calibration method and system for data sampling. Background technique [0002] The global power backbone network is a three-phase AC power system with a frequency of 50Hz or 60Hz. In order to ensure the stable operation of the power system, it is necessary to accurately measure the voltage and current of the three-phase AC. At present, the main measurement technology is computer-based digital measurement technology, that is, through voltage and current sensors (or transformers), high-voltage, high-current signals (that is, the primary signal of the power system) are converted into small-amplitude signals suitable for measurement. The voltage or current signal (that is, the secondary signal of the power system) is then sent to the ADC (Analog-to-Digital Converter) to be quantized and converted into a digital signal, and the collected s...

AI Technical Summary

Problems solved by technology

Even if the two acquisition devices perform strict time synchronization with a cycle of one second, that is, the time of the two acquisition devices is strictly synchronized at the beginning of each second, and the synchronization error is 0, but due to the influence of ±20PPM frequency deviation, in this second At the end, the time of each device will have a deviation of ±20us compared with the standard time, resulting in a cumulative time deviation of up to 40us between the two acquisition devices

The time deviation of 40us will cause a relatively large synthesis error in the synthesized zero-sequence current, which seriously affects the accuracy of fault judgment

Each time synchronization requires data acquisition equipment to consume additional energy. For power-sensitive data acquisition equipment, frequent time synchronization is a huge power consumption burden

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