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Demand Side Response (DSM) is a modern participant at the energy market, and includes both industry participants and households. By each year, their share increases in providing services in the power system and the flexibility at demand side. DSM units in the southeast region are located at different locations, and by their interdependent control, the efficiency of monitoring of neighbour control areas could be significant improved. In order to test the possibility of DSM units, CROSSBOW project develops DSM integration platform, which provides solutions for identification of challenges for interconnection in existing and future power grids at the region and global level while using them efficiently. Moreover, the different measures of DSM units can alleviate established constrains in the interconnection and feasibility of DSM activation, while the technical analysis, regulation requests and constraints still need to be done. DSM platform is going to have communication interface, which can monitor and control regional demand side responses, smart algorithms for integration of DSM units in order to improve power system operation, interface with other control centres, interfaces with coordination platform TSO-DSO, and with applications for the market participants. The experiments in the power grid two connected transmission system operators, HOPS and NOS BiH were done in order to test the level of flexibility of DSM units. The analyses of transitional actions in the power grid introduced by activation of DSM units and the appearance of the disturbance in the congestion period in specific periods, are described in this article. The main purpose of the experiments is to see the impact at the power system security two above mentioned TSOs. The analyse includes the next experiments: i) activation of DSM unit with request to decrease its demand in the period of low consumption, measuring of the power, voltage and current at specific power lines/busses and also switching off of the interconnected power line in specific time periods. Finally, the proposal for the different cases for application of demand side response shall be given.

This paper investigates the use of a game theoretic approach, namely the Monte Carlo Tree Search method, to identify critical scenarios considering transient stability of power systems. The method guides dynamic time domain simulations towards the cases that the system exhibits instability in order to explore efficiently the entire domain of possible operating conditions under uncertainty. Since the method focuses the search within the domain on the cases that are more probable to cause instability, information on stability boundaries and values of parameters critical for transient stability are also provided. Critical lines, penetration level of renewable energy sources and system loading can be defined this way.

The paper discusses reactive power -voltage (Q-V) control in a multi-machine steam power plant (SPP). After briefly introducing some of the basic characteristics of synchronous generator’s voltage control through automatic voltage regulators, the practices of widely applied manual voltage references setting for Q-V control in SPP is illustrated through several examples of SPP response recorded at site. Further the case studies were developed with the emphasis on the drawbacks of manual intra-plant Q-V control by building a mathematical model of realistic SPP in Matlab-Simulink. Relying on noticed drawbacks the paper highlights the requirements for enhancing SPP reactive power response and voltage support to the power system by coordinated Q-V control at power plant level. Finally, the paper illustrates the achieved performances of coordinated Q-V controller in real SPP.

This paper presents details of the practical implementation of a coordinated reactive power-voltage controller (CQVC) developed for a multi-machine steam power plant. The CQVC performs optimal coordination of the synchronous generators' reactive power outputs in order to maintain the total reactive power delivered by a steam power plant (SPP) or the voltage at a steam power plant HV busbar. This is required to achieve slow preventive control of generated reactive powers in order to maximize reactive power reserves along with slow high side voltage control. The CQVC is designed to act through existing automatic voltage regulator inputs, thus no modification of an existing excitation system was made. In order to increase the robustness to changes in operating conditions and to achieve the desired shape of the reactive power response, the two-step predictor corrector method is implemented. A newly developed algorithm for steady state detection ensures non-interference of reactive power voltage control with excitation system response. The paper also presents practical design solutions to overcome limitations posed by application to a real system. Acceptance and functional tests carried out during the commissioning of the CQVC are also discussed in this paper.

The paper summarizes development of coordinated reactive power-voltage controller and PLC based laboratory test rig for multi generator thermal power plant. Theoretical background and basic practical requirements are clearly stated. Following this, several examples are presented to illustrate some of identified advantages and drawbacks of developed test rig during the laboratory testing of CQVC controller which led to improvement both test rig and CQVC controller design. The paper presents full cycle of development of advanced controller, from laboratory test model of steam power plant to practical device. It demonstrates the necessity for and benefits of developing adequate test platform and opens the possibility of its use in further applications.

The paper presents the new, enhanced way of the use of Prony analysis, combined with Padé approximation, for the transfer functions identification. Transfer functions of interests are related to automatic voltage regulator (AVR) and excitation system. In the presented analysis the influence of field voltage recorded signal corruption with noise is successfully overcame. By the use of standard first order synchronous generator model, it is possible to extract exact generator model parameters, using Padé approximation. After that step, the transfer function of automatic voltage regulator (AVR) is derived using similar technique. Finally, derived generator and AVR transfer functions are verified by Matlab/Simulink simulation.