Modeling of SCIG-Based Variable Speed Wind Turbine in Power Factor Control Mode for Load Flow Analysis

As they are more efficient in extracting wind energy, variable speed wind power plants (WPPs) are currently replacing the fixed speed WPPs. One possible way to achieve a variable speed WPP is by using a squirrel cage induction generator (SCIG) with full-scale power electronic converter (PEC). In fact, as its cost is relatively lower, the application of SCIG-based variable speed WPP is gaining popularity nowadays. To be able to perform proper analyses (including the load flow analysis) of an electric power system, valid and accurate modeling of the system components is very important. This paper discusses the steady state model of SCIG-based variable speed WPP in power factor control mode for a load flow analysis of an electric power distribution system. The model was developed based on formulas that calculate the turbine mechanical power input and WPP electrical power output. Integration of the proposed model in load flow analysis is also discussed and presented in this paper.

Review of Electricity Distribution Codes and PV Connection Codes

Electricity is the key driver of the global economy. It is the prime energy resource for supplying customers (industry, irrigation, commerce, service, residence, etc.). This paper discusses technical requirements for Electricity Distribution Codes in various countries. The major similarities and differences between Electricity Distribution codes are clarified. Then, a detailed comparison of photovoltaic systems grid connection codes is presented. The comparison includes voltage and frequency deviations, active and reactive power control, power factor control and fault ride through.

Comparison of Reactive Power Control Techniques for Solar PV Inverters to Mitigate Voltage Rise in Low-Voltage Grids

The greater integration of solar photovoltaic (PV) systems into low-voltage (LV) distribution networks has posed new challenges for the operation of power systems. The violation of voltage limits attributed to reverse power flow has been recognized as one of the significant consequences of high PV penetration. Thus, the reactive power control of PV inverters has emerged as a viable solution for localized voltage regulation. This paper presents a detailed study on a typical Malaysian LV distribution network to demonstrate the effectiveness of different reactive power control techniques in mitigating overvoltage issues due to high PV integration. The performance of four reactive power control techniques namely, fixed power factor control, scheduled power factor control, power factor control as a function of injected active power, and voltage-dependent reactive power control were analyzed and compared in terms of the number of customers with voltage violations, reactive power compensation, and network losses. Three-phase, time-series, high-resolution power-flow simulations were performed to investigate the potential overvoltage issues and to assess the performance of the adoption of reactive power controls in the network. The simulation results revealed that the incorporation of reactive power controls of solar PV inverters aids in successfully mitigating the overvoltage issues of typical Malaysian networks. In particular, the Volt-Var control outperformed the other control techniques by providing effective voltage regulation while requiring less reactive power compensation. Furthermore, the comparative analysis highlighted the significance of employing the most appropriate control technique for improved network performance.