Online analysis method for comprehensive equivalent damping characteristics of regional generator group

Abstract

The invention discloses an online analysis method for comprehensive equivalent damping characteristics of a regional generator group. The online analysis method includes calculating whole-network steady-state trend at first and dividing the regional generator group on the basis of an electrical distance method; establishing a regional equivalent model which has regional generator group equivalent damping characters and is showed as a classic model by the aid of online information provided by whole networks of a wide-area measurement system and an energy management system so as to replace the regional generator group; carrying out model analysis for the whole networks after the regional generator group is replaced by the regional equivalent model, and obtaining influence of the regional generator group represented by the regional equivalent model to small interference stability of the whole networks form two aspects of a main participation model and a correlation factor and model graph of the main participation model, namely obtaining the comprehensive equivalent damping characteristics of the regional generator group. Relative oscillation conditions between a relevant unit with a low-frequency oscillation mode and a generator are provided, connection between the regional generator group and an actual power grid can be realized easily, calculation is simple, anti-interference ability is good, and practicality is high.

Description

technical field [0001] The invention belongs to the field of small-disturbance stability analysis of power systems, and in particular relates to an online analysis method for comprehensive damping characteristics of a generator generator group. Background technique [0002] With the development of regional interconnection, the scale of my country's power system is growing day by day, and the generator sets are characterized by clusters. The problem of low-frequency oscillation between regions has become increasingly prominent, making low-frequency oscillation one of the main obstacles to the safe and stable operation of the entire network. The low-frequency oscillation problem of power system belongs to the category of small-disturbance stability analysis of power system, so the stability of power system with small disturbance has become one of the main stability issues of power system. [0003] With the development of the wide-area measurement system, the power system has r...

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Problems solved by technology

[0005] 1. The signal analysis method based on the online information detection of the wide-area measurement system cannot provide the relative oscillation between the relevant units and generators in the low-frequency oscillation mode;

[0006] 2. The slow coherent equivalent method of the low-frequency oscillation of the whole network cannot effectively use the online monitoring information of the wide-area measurement system. When obtaining the equivalent generator model of the regional generator group through offline aggregation, it is necessary to know all the generators in the regional generator group. Detailed model parameters and start-up status, and simplification of the internal network of the regional generator group is required, the process is cumbersome and the practicability is poor;

[0007] 3. The online modal analysis method requires the wide-area measurement system to set many measurement points at different locations within the entire network to provide sufficient dynamic information to generate the state matrix of the entire network. This method is costly and anti-interference Poor ability;

[0008] 4. Combined with the characteristics of unit clusters in my country's power system, for example, multiple small and medium-sized hydropower units are concentrated in one area, and the following problems exist in the analysis of low-frequency oscillations in the entire network: the participation factor of a single generator for a certain low-frequency oscillation mode is small, but the sum of the participation factors of the generator group to this mode is very large, and the impact of clustered generators in the form of generator groups on this low-frequency oscillation mode can no longer be ignored; most of the existing online low-frequency oscillation analysis methods for the whole network Only focus on whether the inter-regional oscillation mode of the whole network is stable or not, related units and other information, and the research on the influence of regional generator groups on the low-frequency oscillation damping characteristics of the whole network is rarely seen, and relevant research is urgently needed

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