Electric system stabilizing method and stabilizer

Abstract

The invention discloses a stability method for a power system and a stabilizer thereof. Filtering, eliminating direct current component, phase compensation and volt-limiting processing are carried out in sequence; wherein, the transfer function of the phase compensation is determined according to the following steps: 1 obtaining the phase characteristic Phi of a dynamo; 2. calculating the phase compensation characteristic Phi according to the engaged compensation requirement Phi<0> and the phase characteristic Phi; 3. taking the phase compensation characteristic Phi as a target curve to carry out curve fitting, obtaining a phase compensation curve f(x) which approaches the target curve and determining the transfer function of the phase compensation according to the phase compensation curve f(x). The stabilizer comprises a filter, a redactor a phase compensator and a volt-limiting device connected in sequence. The invention can well approach the needed compensation curve by adopting the transfer function of the phase compensation, thus carrying out better compensation for a lagging phase of the dynamo in the whole oscillation range with low frequency.

Description

technical field [0001] The invention belongs to the technical field of electrical engineering, and in particular relates to a method for stabilizing a power system and a stabilizer (Power System Stabilizer, PSS). Background technique [0002] At present, the known PSS structure is composed of a phase compensation link, an additional excitation magnification, a reset link, a sensor and an input signal. Introduce one or two signals to increase the damping torque of the generator in the power system through the excitation system. The commonly used PSS is generally based on the undamped natural mechanical mode frequency jω n Or the complex frequency σ+jω of the local oscillation mode obtained from the system eigenvalue analysis is designed, so the PSS has a good suppression effect on the power oscillation of the design frequency and its nearby frequencies. [0003] With the interconnection of regional power grids, there may be two or more strongly correlated oscillation modes ...

AI Technical Summary

Problems solved by technology

The phase compensation part of the conventional PSS is composed of two or three stages of lead-lag links, which is difficult to meet the requirements. The reason is that: on the one hand, the limit of the lead phase generated by the three-stage lead-lag links is 150°~160°, and many power generation in the power system The generator lag phase often exceeds 200°, which cannot be compensated; on the other hand, the two- to three-stage lead-lag link has only 4 to 6 parameters, and it is difficult to compensate the generator lag phase in the entire low-frequency oscillation range.

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