Análise técnica da cobrança do Fio B para consumidores com geração fotovoltaica conectada em baixa tensão visando a proposta de um componente tarifário justo

Abstract

The expansion of Photovoltaic Distributed Generation (PVDG) in Low-Voltage Distribution Networks (LVDN) has triggered technical, economic, and regulatory changes in the Brazilian electricity sector, especially following the enactment of Law 14.300/2022, which established new rules for the compensation of electricity injected into the grid. In this context, this research evaluates the gradual charging of the Tariff for the Use of the Distribution System (TUSD) Wire B tariff component applied to consumers with PVDG connected to low-level networks. The objective is to analyze whether the current charging structure fairly reflects the technical benefits provided by distributed microgeneration. The methodology is based on the computational modeling of an LVDN using OpenDSS software integrated with the Python programming language. Based on network data, different PVDG penetration levels are simulated, considering scenarios without generation and the progressive insertion of units with PVDG. In each scenario, technical parameters such as consumed energy, injected energy, electrical losses, power flow, and hosting capacity are analyzed. Concurrently, an economic evaluation of the Wire B charge is performed according to the percentages established by Law 14300/2022, alongside the application of Pearson's correlation to relate the technical effects of Distributed Generation (DG) with the current tariff structure. Partial results indicate a reduction in technical losses and transformer load rellef with the insertion of PVDG, particularly during periods of peak solar irradiation. However, excessive injection causes reverse power flow and a subsequent increase in losses. From an economic-regulatory perspective, the results reveal an asymmetry between the technical benefits generated by microgeneration and the current TUSD Wire B charging model, as the tariff predominantly considers injected energy without directly incorporating the positive operational effects provided to the grid. Thus, the research highlights the need for an alternative tariff component that accounts for the systemic benefits provided by prosumers. To solve this distortion, the study proposes two alternative valuation models (\gls{mbptt} and \gls{mbpth}), demonstrating that the minute-by-minute dynamic pricing of \gls{mbpth} promotes tariff fairness by exempting grid-relief periods and selectively charging only for overloading network excesses.