A Bi-Layer Optimization Method for Improved Customer Directrix Line of Distribution Networks Considering Users’ Psychological Discomfort and Voltage Constraint

[Objective] In response to the problem that the incentive mechanism of customer directrix line still has room for improvement and does not consider voltage constraint and low-voltage distribution network users’ psychological discomfort in the implementation process，a bi-layer optimization method for improved customer directrix line of distribution networks considering low-voltage distribution network users’ psychological discomfort and voltage constraint is proposed. [Methods] First，the concept and implementation mechanism of the traditional customer directrix line are analyzed，and its shortcomings such as not considering the influence on system voltage and the psychological discomfort of low-voltage distribution network users are discussed. Second，considering users' psychological discomfort cost and system voltage constraint，a bi-layer optimization model for improved customer directrix line is established. The outer layer of the model optimizes the released customer directrix line and incentive price with the purpose of minimizing the comprehensive cost of the power grid，and finds the solution via the particle swarm optimization algorithm. The inner layer optimizes users’ offset power to minimize users’comprehensive cost，and finds the solution via the interior point method. Then，a demand-side response （DR） implementation scheme based on the proposed improved customer directrix line is proposed. [Results] On the MATLAB platform，the results of the test case based on the IEEE 33-bus system show that the proposed method maintains the voltage at each bus in the system within ±7% of the rated value during the implementation of the improved customer directrix line，and reduces both the solar curtailment rate by around 5.66 % and the economic cost of users compared with those before such implementation. [Conclusions] The formulation of incentive price in the proposed method takes into account the flexible interaction between the power grid and users，and achieves a win-win situation between the power grid and users. At the same time，the proposed method also promotes the photovoltaic （PV） accommodation under the premise that the voltage does not exceed the limit. In addition，it takes into account the influence of psychological discomfort on users’ decision-making，so that the effectiveness of users’ response can be more realistic. This offers valuable insights for the power grid to formulate measures to improve users’ tracking accuracy of customer directrix line.