Stefan Gheorghe

The management of Power quality, Energy efficiency and the performance of the companies

The paper presents a relationship among three important concepts: Power quality, Energy efficiency and Performance of the company operating in energy field. In most of cases, the improvement of Power quality determines an increase of the Energy efficiency and, of course, the increasing of the performance of the company. The balancing between two of them, could give us the optimum solution to act in the strategic plan, which will be implemented. Some ideas for meeting of the scope of each company operating in the energy sector, increasing the performance of the company, are presented in this paper.

Performance of services achieved by transmission and distribution system operators in Romanian power grid

The paper presents an analysis of the performance of transmission system and distribution services in Romania, in accordance with the Romanian Energy Regulation Authority. The paper lists the targets of the new technical regulations, to ensure proper operation of the users connected to the same network node and compliance with power quality indicators by limitation the flicker effect, reduction of harmonic operating regime and maintaining inside approved limits for the asymmetry. The final part of the paper contains the authors conclusions on issues addressed in it.

Results of power quality monitoring in Romanian transmission and distribution system operators

Two types of Power Quality Monitoring Systems (PQMSs) - one for TSO and other for DSOs, in accordance with Performance standards and Technical Codes of the Romanian Energy Regulation Authority - ANRE were published. The connection to the grid of the renewable sources could determine the increasing of the emissivity of perturbations and the necessity of the propagation study in order to determine the level of the perturbation to the superior level of the voltage of network. The concept “One system for all PQ data” is a new direction used by TSO and DSOs for increasing the efficiency of the PQMS. The results of the monitoring using PQMS for a long period of time, in this paper, validated the expectations from the feasibility study in the design stage of PQMS and allowed the authors to look at some improvement directions of the system. The integration of PQMS with other systems - DMS, SCADA, DFR has been already solved in DSO and a higher efficiency has been achieved. The whole measurement chain in power distribution and transmission activities has been taken into consideration and the results have a good accuracy. Few recommendations are included in the paper. The final part of the paper contains the authors conclusions on issues addressed in it.

The connection of renewable sources to the grid. Influences and power quality issues

This paper presents results of power quality monitoring collected from transmission system operator (TSO) and several distribution system operators (DSOs) from Romania. The power quality monitoring system is realized in accordance with actual technologies, economic criteria, performance standards and technical codes issued by the Romanian Energy Regulation Authority (ANRE). The implementation of power quality policies in Romania based on the monitoring and corrective actions determined the improvement of quality of transmission and distribution services in power system. The challenges represented by the connection to the grid of new renewable sources have determined ANRE to issue dedicated regulations. The use of the power quality monitoring systems at the interface between TSO and DSO (Distribution Management System, Fault Recording System, Outage Management System) provides better solutions and leads toan increase in the quality of services. The influence of the short-circuit in the propagation of perturbation in power system represents a challenge within the existing context when many renewable sources are connected to the grid.

Analysis of power quality issues raised by PV generation and e-parking storage capacities in UPB smart grid environment

This paper concentrated on identifying the main issues raised by the adoption of new PV generation and e-cars storage technologies, and their influence on power quality parameters. The main difficulty of this paper was to create a simulation tool which replicates the actual consumption behavior of UPB electric network, and to project scenarios for PV generation and e-cars capacities. A main point in the analysis performed in this work is the characterization of the electric loads present in the upcoming smart grid. An intimate view of a PV system implemented into UPB electric distribution system was delivered, along with its operation mode and its influence on power quality. The full picture was achieved by proposing a reactive energy compensator, which proved to have significant influence in increasing the harmonic distortion indexes and increasing the possible damage hazard for the sensible electronic devices.

Compensation of voltage fluctuations to industrial customers

This paper compares three possibilities for determining the flicker level generated by industrial customer with arc furnaces: by calculating the electromagnetic perturbations, by experimental measurements, and by simulation using specialized software. The influence of the fault level on the propagation of perturbation in the power system represents a challenging issue studied within the existing context. Several mitigation measures of voltage fluctuations have been considered in this paper. A solution is using a STATCOM, which avoids the exceeding of admissible perturbation levels stipulated by the standards.

Smart Grid, Integration of Renewable Sources and Improvement of Power Quality

The paper presents the impact of connecting Renewable sources to the Smart Grid with regard to improving Power Quality aspects. The impact of integrating renewable sources on Power Quality indices in the grid wes analyzed and the measures for avoiding the negative impact are included in the paper. Challenges coming from the integration of renewables – variability and uncertainty and the correlation with smart grid technologies used in the power system are discussed in detail. Aspects related to the exchange of information among different systems used in the Smart Grid–DMS, SCADA, DFR, OMS, MDMS, security of the grid and security of IT networks have been reached in the work. The final part of the paper contains the authors conclusions on issues addressed in it.

The management of renewable sources of energy and their connection to the grid

The paper presents aspects related to the connection of renewable sources of energy to the grid and focuses on the Photo Voltaic Power Plant (PVPP). The correlation of this process with Power Quality (PQ) issues and conditions for certification of each plant in accordance with regulations are included in our work as well. Results of measurements of PQ in the Points of Common Coupling (PCC) in the Romanian Power Grid using renewable sources allow us a comparison with the theoretical expectations from other works. The challenges related to the connection of renewable sources of energy to the grid have been reached in our paper.