Proposed Fuzzy Logic System for Voltage Regulation and Power Factor Improvement in Power Systems with High Infiltration of Distributed Generation

Abstract

Recently, the awareness of the severe consequences of greenhouse gases on the environment has escalated. This has encouraged the world to reduce the usage of fossil fuels for power generation and increase the use of cleaner sources, such as solar energy and wind energy. However, the conventional power system itself was designed as a passive power system, in which power generation is centralised, and power flows from substations towards the loads. Decentralised renewable energy sources, also called distributed generators, were introduced to create an active power system in which power generation can occur anywhere in the power system. Decentralised power generation creates challenges for the conventional power system, such as voltage fluctuations, high voltage magnitudes, reverse power flow, and low power factor. In this paper, an adaptive control system that coordinates different distributed generators for voltage regulation and power factor correction is introduced and designed. The control system will decrease the total reactive power that flows in the transmission network through a reactive power exchange between distributed generators. Therefore, power factor will improve, power system losses will reduce, and the total apparent power on lines will reduce, giving more room to active power to flow. The results obtained showed that the control system is effective in regulating voltage and improving the power factor when multiple distributed generators are connected.

An Average Voltage Approach to Control Energy Storage Device and Tap Changing Transformers Under High Distributed Generation

“…Literature has explored and proposed multiple techniques that enhance voltage regulation in active power distribution networks and also use a BESS for efficient power system operation. In [14], a technique is proposed that coordinates multiple DGs to control voltage and refine the power factor. In [16], another technique is proposed that controls voltage and reduce power losses using reactive power from DGs.…”

“…However, since DGs are being connected to a power system with existing voltage regulation devices, DGs voltage control capabilities must be coordinated with existing devices for optimal voltage regulation. By not coordinating DGs and existing voltage regulation devices, strategies in [14] and [16] will lead to conflict between devices and the overutilization/underutilization of some devices. In [17], a technique is proposed that uses a BESS in a low voltage active distribution network to control voltage.…”

“…When the electric vehicles SOC is not low enough to alleviate the voltage rise, the controller will curtail the active power generated by DGs. Although the techniques summarised in [14][15][16][17][18][19][20][21][22][23][24][25][26][27] are effective in regulating voltage magnitudes to a certain extent, their effectiveness can be enhanced by introducing an average voltage method of voltage regulation instead of a single point voltage regulation method. This is because the methods in literature control the OLTC and SVR with respect to a fixed reference voltage, or a reference voltage computed based on the highest/lowest measured/estimated voltage magnitude.…”

“…It will further utilize a battery energy storage system (BESS) to enhance voltage regulation and reduce the number of tap operations on both the OLTC and SVR. DGs also have voltage regulation ability through the usage of reactive power, however, literature has highlighted the impact that the exchange of reactive power between the network and DGs have on the electrical network power factor [13][14][15]. Therefore, the proposed scheme will also utilize DGs reactive power to further assist in enhancing voltage regulation and boosting power factor.…”

Adaptive Algorithm of a Tap-Changer Controller of the Power Transformer Supplying the Radial Network Reducing the Risk of Voltage Collapse

“…However, in networks with a high saturation of distributed generation, the efficiency of such a method of voltage regulation is increasingly often insufficient. High generation variability (wind, photovoltaic generation) deteriorates the voltage profiles on the grid [2][3][4][5][6][7][8][9]. An equally important problem is periodically too low or too high voltage in the network [10,11].…”