This paper presents the use of real-time digital simulator (RTDS) and hardware-in-the-loop (HIL) methods for the validation of an energy management system designed for real low-voltage (LV) distribution networks with a high penetration of renewable energy sources. The system is used to address voltage violations and current overloading issues and allows the network operator to maintain safe and controllable network operations. The applied control strategy and the system software were verified by means of simulations. In this paper, the next stage of system validation using the HIL method is presented. A testbed was designed and developed to test the operation of prototype controllers of the system in flexible and reproducible conditions before installing them in the network. The presented testing platform not only includes the LV network simulator with the power amplifiers needed for closed-loop setup but also additional elements of a real network to which the system is dedicated, i.e., the advanced metering infrastructure, photovoltaic source, and energy storage inverters and load devices. Furthermore, the real cellular network of the distribution network operator is used in the communication between the controllers. In addition, the article contains discussions on communication issues, including limitations related to selected protocols. Finally, examples of the experimental validation of the controller prototypes are presented.

Designing a power supply of a newly built property, investor has at his disposal whole range of technologies, skillful selection of which will minimize the total cost of supplying the facility with energy. Apart from renewable energy sources like photovoltaics, wind turbines or solar heating, classical technologies like district heating, micro/mini cogeneration unit or gas boiler can be used. For an optimal use of a complex power system, energy storages may be necessary, as well as an advanced control system. The choice of the property power supply structure is extremely important, because this decision will impact the costs that will be incurred by the owner over the next few decades. This article shows how to select the structure and parameters of power supply of residential premises, taking into account the characteristics of consumption of electricity, heat and weather conditions. The obtained solutions were analyzed depending on availability of district heating and local generation, adopted electricity tariff, as well as energy and capacity prices. The results demonstrated profitability of local generation in the form of cogeneration and wind energy for own consumption, while local generation focused on electricity sale to the grid and PV installations proved to be not economically feasible.

One of the main tasks of the Power System Operators is to ensure a proper, safe, and trouble-free operation and development of power grids. Growth of power system is inseparably linked to a connection of both renewable and classical new energy sources. For network operators and potential investors, it is essential to know the place and volume of generation capacity that can be connected to the grid. A publication of such data is currently a legal obligation for many operators. This paper proposes a method of determining the bus connection capacity in power grid of any type with the use of black-box optimization. Calculations and analyses were performed with a full, nonlinear model of the analyzed network. Obtained results show the effectiveness of this method for both single and multiple nodes in any configuration. All the constraints relevant for the proper and safe system operation, such as bus voltages, line loads, and short-circuit currents, both in a steady-state and (n-1) contingency states, are taken into consideration. Calculations confirmed the good convergence and repeatability of the method for all three tested computational algorithms. This has also confirmed the possibility of use of open source software to extend the functionality of Siemens PSS^®E commercial power system calculation software.