Voltage stabilization online monitoring phasor data measurement device and phasor measurement method

Abstract

The invention discloses a voltage stabilization online monitoring phasor data measurement device and a voltage stabilization online monitoring phasor measurement method. The device comprises a synchronous clock unit, an acquisition unit, an input unit, a dual-port random access memory (RAM) transmission module, a data management unit and an output unit. A precise global positioning system (GPS) synchronous clock signal serves as a reference of a sampling process, so that phasors of each sampling channel are in a determined and uniformed phase relationship; a digital signal processor (DSP) is used for data acquisition and phasor calculation; an embedded real-time operating system and graphical user interface-based ARM9 takes charge of data management and communication, has the characteristics that the processing capacity is high, the real-time is high, the ARM9 is easy to upgrade and the like and improves the reliability, the network communication capacity and the expandability of the measurement device; tripping and closing are executed accurately and reliably according to an upper computer command; the DSP adopts an alpha-beta coordinate system-based phasor measurement algorithm,has the advantages of high computing speed, high suitability and high accuracy, and can accurately compute the information of a voltage / current signal phasor of a power grid; therefore, the problem of spectrum leakage when a signal frequency fluctuates greatly is avoided effectively, and the measurement precision of a non-power frequency input situation and a dynamic process is ensured.

Description

Technical field [0001] The invention relates to a voltage stabilizing device for a power system, in particular to a voltage stability online monitoring phasor data measuring device and a phasor measuring method. Background technique [0002] With the development of modern power systems, the scale of the system continues to expand, the network structure is becoming increasingly complex, and the constraints of environmental and economic factors make the operation of the power system closer to the limit conditions. In recent years, voltage instability accidents have occurred in different power systems all over the world, and have caused major power outages in the system, seriously affecting social and economic life. The direct cause is that after the line is short-circuited, the line protection device cuts off part of the line, which leads to a large-scale transfer of the original line power, causing insufficient reactive power, insufficient dynamic power of the generator, causing a...

AI Technical Summary

Problems solved by technology

Since the power system is a nonlinear time-varying system, its state is changing all the time, so for the load shedding device, when the setting value is smaller than the actual required load shedding after the fault occurs, the action of the low-voltage load shedding device cannot To prevent the voltage collapse of the system, when the setting value is larger than the actual required load shedding after the fault occurs, the busbar in some areas of the system is prone to overvoltage, which may lead to serious consequences;

[0005] (2) The operating condition of the existing low-voltage load shedding device is only to judge whether the voltage has dropped to the set voltage threshold, and does not consider the operating condition of the device from the perspective of voltage stability indicators

This device may cause two adverse effects: if the voltage threshold is set too high, it may cause miscutting; if the voltage threshold is set low, it may cause voltage instability;

[0006] (3) Although this type of device has du / dt automatic locking function, it can only be effectively locked when the three-phase voltage at the installation point drops rapidly at the same time, and cannot accurately and effectively cut off the power load

[0007] At present, there is still a lack of power quality monitoring devices that can achieve high-precision measurement, fast detection, and effective load shedding by using only local measured phasor information in substations.

Images