Assessment of overvoltage mitigation techniques in low‐voltage distribution networks with high penetration of photovoltaic microgeneration

Abstract

Nowadays, a strong concern to decrease greenhouse gas emissions is encouraging the implementation of renewable energy sources closer to end-users, in low-voltage (LV) distribution networks. Due to the expected high microgeneration (µG) penetration level, several problems are likely to arise, such as overvoltages and reverse power flow. This study presents a review of the several techniques used to deal with these problems. These are compared in terms of their capacity to smooth the voltage profile and avoid reverse power flow. An unbalanced three-phase power flow algorithm, based on current summation method for radial distribution networks, is proposed. A study based on a highly unbalanced test radial LV distribution network for a typical summer day, with a high µG penetration, is performed. The voltage profile, active power flow in the service transformer, and power losses on the network are the monitored electrical quantities. The obtained results indicate that self-consumption with storage is the recommended solution to eliminate overvoltages, to avoid reverse power flow and allow for a decreasing in the power losses. Nevertheless, the economic viability of this solution must be carefully assessed, because the profitability of the project is not straightforward at the current time.

Performance analysis of grid-tied photovoltaic system under varying weather condition and load

“…Reactive power and voltage control [9][10][11][12][13] and PV system power curtailment [14][15][16] are proposed methods in the existing literature to improve the distribution grid voltage profile and reduce observed overvoltage during variation of generated power by the grid-tied PV system. Since the power, the PV system produces depends much on weather conditions, like solar radiation and temperature, which varies.…”

Improvements in Bidirectional Power-Flow Balancing and Electric Power Quality of a Microgrid with Unbalanced Distributed Generators and Loads by Using Shunt Compensators

“…For unbalanced-load current compensation, the compensator should eliminate the entire negative-sequence component and the imaginary part of the positive-sequence component of the load current, as shown in Equations (18) and (19) [26,27]. By combining Equations (18) and (19), the compensation command of the delta-connected compensator is obtained for each arm, as presented in Equation (20). The rating of the compensator can also be determined from Equation (20).…”

“…The compensator connected at Bus n can compensate for the imaginary part of the positive-sequence load side current and the entire negative-sequence load side current. For example, if the compensator is connected at Bus 1, then the compensator executes the compensation rule presented in Equations (18) and (19). Thus, the power source side only supplies a balanced three-phase current with a unity power factor, and the power quality is improved.…”

“…In [13][14][15], authors explore a reverse power problem and load-balancing technique in a microgrid. Authors in [16][17][18][19][20] have discussed reactive power control and voltage regulation issues in microgrids. However, a compensation scheme integrating bidirectional power-flow balancing and EPQ improvement in a three-phase microgrid is seldom seen.…”

The Impacts of Distribution Generators’ Size and Location on Power Efficiency and Voltage Profile in Radial LV Networks

“…This has resulted in decreasing the average annual electricity demand which amounts to 24 percent reduction. In [13], the author provided a review of high penetration of photovoltaic micro-generation on a low voltage distribution network. The study proposed an analytical method to study the effects of high penetration of PV on the radial distribution network.…”