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The interconnection of single-phase households DG into the existing grid requires appropriate anticipation to ensure the quality and reliability of the existing system. This paper deals with the optimal placement and sizing of multi single-phase DG in unbalanced distribution systems for power loss reduction and voltage improvement while maintaining voltage unbalance and harmonic are in the acceptable limit. Optimal location and sizing of DG are determined simultaneously using the improvement version of Symbiotic Organisms Search (SOS), called Dual-Phase Parasitism SOS (DPP-SOS) with a crossover operator. DPP-SOS consists of original parasitism (OP) and random weight parasitism (RWP). DPP-SOS was programmed using MATLAB software and validated using 26 benchmark functions. To demonstrate the effectiveness of this method in reducing losses, the DPP-SOS is also tested using 7, and 25 bus test systems. Result show that DPP-SOS with a crossover operator has been successful in determining the location and rating of single-phase and three-phases DG simultaneously. DPP-SOS has an average convergence speed of 24.08% faster than the basic SOS. The simulation result also shows that multi single-phase DG is effective in reducing power loss, increasing voltage, and reducing voltage unbalance in the distribution system. [ABSTRACT FROM AUTHOR]

This paper proposes a dual UPQC system model supplied by two PV arrays and then called the 2UPQC-2PV system to enhance load real power flow performance in a 380 V (L-L) low-voltage 3P3W distribution system with a frequency of 50 Hz. The 2UPQC-2PV configuration is used to maintain the load voltage and enhance the real load power performance in the event of an interruption voltage disturbance on the source bus. The performance of the 2UPQC-2PV configuration is further validated with the 2UPQC and 2UPQC-1PV configurations. The simulation of disturbance in each model configuration consists of six operating modes (OMs) i.e. OM 1 (Sinusoidal-Swell-Non Linear Load or S-Swell-NLL), OM2 (S-Sag-NLL), OM 3 (S-Interruption-NLL or S-Inter-NLL), OM4 (Distorted-Swell-NLL or D-SNLL), OM5 (D-Sag-NLL), and OM 6 (D-Inter-NLL). The Dual-Fuzzy-Sugeno (Dual-FS) control method is used to overcome the weaknesses of the dual-proportional-integral (Dual-PI) control in determining the optimum parameters of proportional and integral constants. In OM 3 and OM 6, the 2UPQC-2PV configuration with Dual-PI and Dual-FS controls is able to maintain a higher load voltage than the 2UPQC and 2UPQC-1PV configurations. In OM 6, the 2UPQC configuration with the dual PI and dual FS methods is able to produce the lowest average (Total Harmonic Distortion (THD) of load voltage compared to the 2UPQC-1PV and 2UPQC-2PV. In OM 3 and OM 6, the 2UPQC-2PV configuration with Dual-PI and Dual-FS controls is capable of producing higher real load power, compared to the 2UPQC and 2UPQC-1PV configurations. In OM 3 and OM 6, the 2UPQC-2PV configuration with the Dual-FS method is able to produce higher load real power, compared to the Dual-PI method. Furthermore, in OM 3 and OM 6, the 2UPQC-2PV configuration with the Dual-FS method is also able to produce higher dual-UPQC efficiency, compared to the Dual-PI method. In the case of interruption voltage disturbances with sinusoidal and distorted sources, the 2UPQC-2PV configuration with dual-FS control can enhance load real power performance and dual-UPQC efficiency better than dual-PI control. [ABSTRACT FROM AUTHOR]

Large distributed generation (DG) penetration into the power system needs to be accompanied by proper planning to maximize the benefits and minimize the negative effects that may arise on the system. Determining the location and size of DGs in power systems is a complex issue because it involves hundreds or even thousands of buses and lines distribution. Various studies have been conducted to overcome these problems, including by developing existing methods or even discovering new methods. This study deals with location optimization and sizing DG in the radial distribution system to minimize power loss and voltage deviation. The location of the DG is identified using a loss reduction sensitivity factor (LRSF) while the size of the DG is determined using the improved method of symbiotic organisms search (SOS) called New Enhanced SOS (NeSOS). There are two methods developed in the NeSOS, namely random weighted inverse vector (RWIV) and dual-phase parasitism (DPP). DPP consists of classic parasitism (CP)and random weight parasitism (RWP). The NeSOS is programmed under MATLAB software and validated using 26 mathematical benchmark functions. NeSOS also tested on IEEE 33 and IEEE 69 bus test system and compared with other methods. The simulation results show that the convergence rate of NeSOS is 30% faster than SOS. NeSOS also provides an average power loss of 1.53% lower than other methods. [ABSTRACT FROM AUTHOR]

This paper presents enhancement of load active power transfer using Unified Power Quality Conditioner-Photovoltaic-Battery Energy Storage (UPQC-PV-BES) system. This system is connected to a three phase three wire (3P3W) system with a voltage of 380 V (line to line) and 50 hertz. The proposed model is also compared with UPQC and UPQC-PV respectively. The parameters investigated are load voltage, load current, load active power, and efficiency. BES functions to save excess energy generated by PV, distribute it to the load, avoid interruption voltage, and regulate the charging process and energy utilization. The fuzzy logic controller (FLC) is proposed and compared with proportional integral (PI) method to control DC voltage variable and input DC reference voltage, to produce a reference current source on hysteresis current controller on shunt active filter in 12 disturbance scenarios (scns). In Scenario (Scn) 1 to 5, the 3P3W system uses three combinations of UPQC with PI controller and FLC, still keeps load voltage and load current above 300 V and 8 A. Whereas in Scn 6, only the UPQC-PV-BES with FLC is able to maintain load voltage and load current higher compared to UPQC and UPQC-PV combinations as 304.1 V and 8.421 A, respectively. In Scn 1 to 5, the 3P3W system uses three combinations of UPQC with PI controller and FLC, capable of producing load active power above 3600 W. Whereas in Scn 6, only a combination of UPQC-PV-BES with PI controller and FLC is able to produce a load voltage of 3720 W and 3700 W, respectively. In Scn 1 to 6, UPQC-PV-BES results in lower efficiency compared to using UPQC and UPQC-PV. However, in Scn 6, UPQC-PVBES with FLC is able to produce load voltage, load current, and load active power higher than UPQC-PV and UPQC. Thus, the UPQC-PV-BES model using FLC is able to compensate load voltage and load current, as well as to enhance load active power, especially for an interruption on source bus. This research is simulated using Matlab/Simulink. [ABSTRACT FROM AUTHOR]