DIGITAL MODELS PERFECTION FOR SOLVING PROBLEMS OF IPS/UPS SYSTEMIC RELIABILITY

摘要

The high level of the systemic reliability of IPS/UPS synchronous zone is provided due to continuous scientific and technical support of its development and day-to-day operation. As one of the basic research tools the digital models of the whole power system and its separate fragments are applied. At the same time the principle of the common infobase is applied during various digital models creation. With the advent of new microprocessor regulating devices in the UPS of Russia, implementing complex control laws, the available digital models of electric power systems became inadequate from the point of view of providing both a quantitative assessment of stability margins, and a qualitative coincidence of the history of electromechanical transients to a reality after normative perturbations. This has led to the necessity of perfection of digital models of complex power systems by including in their structure detailed microprocessor control devices models. In the modern dynamic models the most detailed representation is used for the automatic voltage (excitation) controllers (AVR) and power system stabilizers (PSS). Digital modeling of the AVRs and PSSs is carried out using their full mathematical description. For the creation of digital models of modern domestic AVRs the EUROSTAG and PSS/E software are used. In the environment of this software the full digital models of semi-conductor, analog-digital and digital excitation controllers were realized. The adjustment and verification of AVR digital models is made by the comparison of the response characteristics of regulating channels with the data of tests of industrial samples or the data provided by the AVR producers. Response characteristics of the microprocessor AVR are distinguished by their high stability, therefore it is sufficient for them to verify the typical model. After that the model can be applied for any generator for the sampling of the adjustment of AVR channels. All semi-conductor excitation controllers have specific features, therefore their models for each concrete installation requires additional tuning, which is carried out on the base of full-scale test data. Example of verification of the model of analogue excitation controller and PSS of the North-West TPP is given in the report. Aforementioned approaches guarantee the reliability of operational computations with the use of digital models and allow to use them for solving various problems, such as the analysis of emergencies and development of recommendations of their prevention, examinations of various projects regarding maintenance of transient and small-signal stability, adjustment of the power system stabilizers on functioning installations, analysis of low-frequency oscillations, sampling of adjustments of counter-emergency automatons, etc. Examples of practical use of IPS/UPS reference digital model and its separate fragments are given in the report.