A Method for Optimizing Voltage and Reactive Power of Distribution Network Based on Bart Algorithm

Abstract

The invention discloses a power distribution network voltage reactive power optimization method based on a BART algorithm. The BART algorithm is an integrated predication method, an accumulative regression tree model is decomposed into a plurality of weak regression trees through a non-parametric Bayesian regression method, and an integrated predication system is formed through an integrated method. Each weak regression tree is in charge of a small part in the entire integrated predication system, and the influence, on predication, of a single regression tree module is weakened to improve the predication effect of the entire integrated model. According to the power distribution network voltage reactive power optimization method based on the BART algorithm, based on self learning of historical sample data and under the premise that voltages are in a reasonable controlled range is guaranteed, the actions of adjusting a transformer tap and the actions of switching of a capacitor bank are as less as possible, under the idea state that the voltages on the lower voltage side of a transformer and the reactive power are small in transmission loss, complex optimization models do no need to be solved in the optimization process, the influences of loads, the voltages and the reactive power are completely considered, and flexible adjusting is conducted on reactive power.

Description

Technical field [0001] The invention belongs to the field of power system relay protection automation, and relates to a distribution network voltage and reactive power optimization control method, in particular to a distribution network voltage and reactive power optimization control method based on a BART algorithm. Background technique [0002] In the power system, the power distribution system needs to perform reactive power management to ensure that the voltage is within the normal control range and reduce network losses. The factors that affect system voltage and reactive power include engine voltage, transformer tap position, shunt capacitors, reactor banks, and system loads. At present, the main equipment used for voltage and reactive power regulation in most substations in my country is on-load voltage regulating transformers and Parallel compensation capacitor bank adjusts voltage and reactive power by adjusting the transformer tap position and switching the parallel capa...

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Problems solved by technology

[0003] The literature "Research on Voltage and Reactive Power Control Strategies of Substations under AVC Decentralized Control Mode" lists several voltage and reactive power control strategies commonly used in substations: (1) Control according to the power factor: if the power factor is lower than the lower limit, the capacitor bank is used, and the high If the upper limit is lower than the upper limit, the capacitor bank will be removed; however, the power factor is only a part of the reactive component and cannot accurately reflect the reactive component of the grid load. (2) Control according to the level of the bus voltage: mainly adjust the voltage and reactive power according to the level of the voltage

The defect is that the condition of reactive power balance is not considered. According to the actual operation results, the compensation effect of this method is poor; (3) Comprehensive control based on the nine-zone map: the current operating area is judged by real-time voltage and reactive power information, and then according to The control strategy of the nine-area map adjusts gears and switches capacitor banks; in the control strategy of the nine-area map, the boundaries of voltage and reactive power are fixed, which cannot reflect the mutual influence of voltage and reactive power, and there are no restrictions on the use of control equipment. It meets the actual operation requirements and may lead to voltage instability; (4) seek the optimal control strategy based on the global planning based on the short-term load forecast, according to the short-term load forecast value, the transformer tap and the maximum allowable capacitor bank in a day The number of actions is the optimization condition, establish the objective function involving the state variable secondary side voltage and incoming line reactive power, solve the optimization problem to determine the position of the voltage tap and the switching of the capacitor; the difficulty lies in the establishment and solution of the objective function; (5) based on Fuzzy control of artificial intelligence: extract fuzzy rules on the basis of nine-zone map control, and optimize adjustment strategies

However, the robustness and reliability of fuzzy control are poor, and it is subjective, so it cannot make full use of the characteristics of sample data; (6) Artificial neural network control: Introduce the learning and self-adaptive ability of neural network into voltage and reactive power regulation Among the problems, this method has strong fault tolerance, but the structure and operation mode of the power system are constantly changing, and there are not enough training samples, so it is difficult to quickly train the neural network model

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