Three-phase unbalanced virtual resistance optimization method based on co-evolution

Abstract

The invention provides a three-phase unbalance virtual resistance optimization method based on co-evolution, relates to the field of electric power design, and is applied to districts subjected to unbalance voltage compensation. The method comprises the steps as follows: establishing a three-phase power flow model under the specific operation condition of districts, and deriving a voltage evaluation function taking virtual resistance as an independent variable and representing unbalance degree of voltage and a grid loss evaluation function representing grid loss respectively according to the three-phase power flow model; establishing a virtual resistance optimization model with the weighted sum of the to-be-optimized voltage evaluation function and the grid loss evaluation function and each virtual resistance as a decision variable; solving virtual resistance of the virtual resistance optimization model with a co-evaluation algorithm and determining a virtual resistance optimization scheme applicable to the specific operation condition. The method can solve the problem of confliction of control strategies of inverters in all positions, and the unbalance control effect and the lineloss limit effect can be optimized.

Description

technical field [0001] The invention relates to a three-phase unbalanced virtual resistance optimization method based on co-evolution, which belongs to the field of electric equipment design. Background technique [0002] Steady-state power quality mainly includes harmonic problems generated by nonlinear loads, three-phase imbalance problems caused by asymmetric load distribution, and voltage flicker caused by high-power equipment startup. The main distinguishing feature is waveform distortion. Among them, the power quality problems caused by three-phase asymmetry are the most common. [0003] There are a large number of single-phase loads in my country's low-voltage distribution network, especially in rural areas. Due to the wide area, there are many and scattered users, the random access of new users is not carried out in the system planning, resulting in Unbalanced three-phase load. Unbalanced three-phase load distribution will lead to asymmetrical three-phase voltage at...

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Problems solved by technology

[0003] There are a large number of single-phase loads in my country's low-voltage distribution network, especially in rural areas. Due to the wide area, there are many and scattered users, the random access of new users is not carried out in the system planning, resulting in Unbalanced three-phase load

Unbalanced three-phase load distribution will lead to asymmetrical three-phase voltage at the transformer outlet, and voltage asymmetry will cause power quality problems such as unequal amplitudes and angle deviations, which will affect the quality of power supply for users

However, in the actual distribution network, due to the wide power supply range of a single area, it is necessary to configure unbalanced inverters in multiple locations. To maximize the effect of the inverter absorbing unbalanced power, it is necessary to achieve the maximum absorption of unbalanced power in the distribution network and maximize the effect of loss reduction

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