Preparation for Large Scale Wind Integration in SEE Power System
for: SEE TSOs (USEA, USAID)
type: Study
finishing date: December 2011
team: EKC-EIHP Consortium, EKC team: Dj. Dobrijevic - Project Leader, M. Vukovic - Consultant, T. Martinovic, B. Sijakovic

In this study analyses of large scale wind integration in electric power systems of SEE have been performed. Time horizon are years 2015 and 2020. Following analyses have been performed:

•  Collection and review of information from wind integration studies and other relevant studies;

•  Collection and review of WPP project data, current regulation practice and rules for connection of WPPs

•  Analysis of large scale wind penetration in the electric power systems of SEE for characteristic regimes in 2015 and 2020;

-        Load flow analysis
-        Voltage profile analysis
-        Contingency (n-1) analysis
-       Identification of grid constraints and needs for grid reinforcements

•  Calculation of estimated balancing power needs and availability.

The main result of the study is utilization of appropriate best practice wind integration standards identified to develop a reference document for use by SECI participants.

In addition, the goal is to detect grid constraints and needs for reinforcements as well as to assess the future needs of power system regulation with respect to the new elements in power system.                            

The following activities have been performed:

·       Consultant services
·       Collection and review of information from wind integration studies and other relevant studies;
·       Collection of WPP project data, current regulation practice and rules for connection of WPPs;
·       Creation and verification of base load-flow models (characteristic regimes)
·       Load-flow analysis and identification of grid constraints and needs for grid reinforcements;
·       Calculation of estimated balancing power needs;
·       Utilizing appropriate best practice for wind integration standards for develop a reference document.

Western Serbia – 400 kV Transmission System Upgrade
for: EMS (Serbia), WYG (United Kingdom)
type: Feasibility Study
finishing date: September 2011
team: S. Markovic – System planning and analyst engineer, P. Miksa – Consultant, Т. Martinovic

The aim of the feasibility study (FS) is to examine possible phasing options for reconstruction of transmission lines in western Serbia until 2015 and in line with long-term development plans. At this point there is no adequate network capacity and equipment is quite old. This negatively affects the transmission capacity in the region, especially taking into account the construction submarine cable between Montenegro and Italy and the expected increase in transit through the transmission network in Serbia, and the necessary reconstruction and achievement of a 400 kV voltage level is the best solution. The main activities in FS will be to review the technical analysis conducted at the Pre-feasibility Study (PFS) stage and undertake further analysis in order to fully evaluate the proposed projects from the technical perspective. In order to achieve appropriate results, it was necessary to perform the following activities:

• EMS’s model preparation which is used in the FS. All assumptions that are specified include interconnection B.Basta to Pljevlja (double circuit), Vardiste normal configuration, Bistrica new 220 kV Substation, B.Basta to Sremska Mitrovica line available including all items studied as sensitive in the PFS.

• To carry out the analysis at the level of the Pre-feasibility study which consists of modeling of 400 kV Kragujevac – Kraljevo line and 400kV new 400kV Bajina Basta - Kraljevo line.

• To identify the periods and critical regimes when OHL between B. Basta and Valjevo/Obrenovac/Beograd-3 can be switched out and what is the consequence in terms of unsupplied energy to both EMS (and EPS).

• Assess the usage of Phase-shifting transformers in Bajina Basta for 400/220kV transmission in the long term period

• Short circuit analyses in accordance to IEC 60909 standard, considering full engagement of all generation units in Serbia. This item was performed for Winter maximum 2015 regime.

The following activities have been performed:

·       Data Collection
·       Load flow analyses
·       Short circuit analyses
·       Techno-economical analyses
·       Construction Planning

Study of Electric Power and Energy Losses in Transmission Network of Power Utility of Montenegro (EPCG) with Measurements for Their Reduction
for: CGES (Montenegro)
type: Internal Study
finishing date: September 2011
team: D. Orlić – Project Manager, M. Vuković – Consultant, A. Oros, Dj. Dobrijević, B. Šijaković

Objective of this study is to evaluate power losses in transmission network of Montenegro and to propose measures for their reduction. In order to calculate power losses deterministic methodology was used (load flow calculations) based on real time recorded data. Within the scope of the study was also to evaluate measurement devices installed in Montenegro network, weather they have sufficient accuracy for electric energy metering. Influence of different production patterns, exchange scenarios and transmission network development scenarios on level of power losses was examined too.

The following studies have been performed:                       

•   Load flow and voltage profile analyses
•   Power losses calculations and analyses
•   Statistical analyses of the huge number of “snap-shots”

The following activities have been performed:

·  Critical analyses of the level of losses in transmission network of Montenegrin power system in the period 2006-2010.
·  Development of the measures that should lead to losses reduction that are find viable and technically and economically feasible
·  Calculation of the level and structure of the losses in transmission network of Montenegrin power system in the period 2006-2010.
·  Analyses of the level of technical loses as well as their „vertical“ and „horizontal“ structure
·  Analyses of the influential parameters (network elements characteristics, voltage profile, transits, compensation, …).

Lastva to Pljevlja 400kV transmission line, Lastva 400/110 kV substation and 110 kV diversions (EKC: System Study)
for: CGES (Montenegro), WYG (United Kingdom)
type: Feasibility Study
finishing date: September 2011
team: Z. Vujasinović – Transmission Planning Engineer, D. Orlić– System Analyst

The aim of the System Study within Feasibility Study (FS) for Lastva-Pljevlja project (containing line 400 kV Pljevlja-Lastva, SS Lastva 400/110 kV, and 110 kV lines diversions from SS Lastva), is to review of the available studies regarding further development of the Montenegrin HV transmission network studies, and to perform detailed system analyses using PSS/E software package encompassing the following calculations:

a)        Steady state AC Load flow
b)        Analysis of voltage profiles
c)        Contingency, (n-1) security assessment
d)        Assessment of transmission grid losses
e)        TTC (NTC) evaluation, direction from Serbia & BiH to Montenegro, with/without new 400 kV line
f)         Analyses of short-circuit currents

The following activities have been performed:

·       Data Collection
·       Review of existing studies
·       Load flow and contingency analyses
·       Voltage Profile
·       Short circuit analyses
·       Network losses
·       TTC/NTC calculation
·       Preparation of the Report.

Black Sea Regional Transmission System planning project - phase III
Economic model development and electricity market and RES evaluation, Regional model 2015 and 2020 update
for: BSTP, USEA
type: Study
finishing date: April 2011
team: P. Mikša – Task Leader, M. Vuković – Consultant, N. Jović – Network Analyst, T. Martinović – Network analyst, Z. Vujasinović – Team member

Objective of this study is to collect national inputs and the development plans for further update of regional transmission model that will be used for power transmission system analysis for 2015 and 2020, thus promoting regional cooperation in transmission planning among Black Sea region TSOs. In the scope was to analyze the regional electricity market and its influence on transmission system to identify the existing potential for electric power trade in the region as well as the level of renewables production penetration and influence on regional electricity market.

Stock Taking: Regional Power Trade in Southern Caucasus
for: World Bank
type: Study
finishing date: August 2011
team: Z. Vujasinović - Project Leader, P. Mikša – Consultant, S. Mijailović, M. Stojković

Study has the goal to assess the current state of power sectors in the region of Southern Caucasus, evaluate their preliminary investments needs, and identify potential policy and investment actions that will facilitate regional electricity trade. The study will recommend ways to improve electricity trade between South Caucasus countries as well as their neighbors so that Armenia, Azerbaijan and Georgia could meet their projected energy needs.

Specific tasks:

- Status of the present power system, basic data
- Power demand forecast for the period 2011-2025
- Power supply forecast for the period 2011-2025 (snapshots for 2015, 2020, 2025):
- Armenia, Azerbaijan and Georgia: Interconnection possibilities and operational rules and standards
- Power surplus/deficit analysis for the target years 2015, 2020 and 2025.

The following activities have been performed:

·       Data collection
·       Review of supply, demand and transmission forecasts
·       Surplus/deficit analysis
·       Recommendations for improving the regional electricity trade
·       Final Report.

Development of a Grid Code for the transmission system of Montenegro
for: CGES (Montenegro)
type: Consulting Services
finishing date: July 2011
team: N. Jovic - Project Leader, M. Vukovic - Consultant, A. Oros

The objective of the project is to establish planning, operational and connection standards in order to provide reliable, secure, economic and coordinated operation of the Montenegrin transmission grid and also to enable development, maintenance, and management of the transmission system in accordance with the ENTSO-E rules and good European practices in this field. This is achieved through the following:

o  Specification of the minimum operational standards, technical requirements, services and relations to the electricity market and information procedures for current and potential network users in an objective, non-discriminatory and equal way

o  Establishing responsibilities and obligations for Montenegrin TSO and for all the users of the Montenegrin transmission network

o  Establishment of requirements and criteria for the development of the Montenegrin transmission network

o  Linking to the national legislative documents (new Energy Law of the Republic of Montenegro, Market Rules and an appropriate tariff methodology etc.) and international guidelines and legislative documents (ENTSO-E Operational Handbook, Agency for the Cooperation of Energy Regulators, European Commission) as well as other related documents

Grid Code development for transmission system of Montenegro contains the following phases:

1.  Review of the existing grid code and Energy Law and other input data compatibility, determination of new grid code structure and development concept 

2.  Preparation of the draft version and harmonization with the TSO’s officials for each Section in the grid code (Long-term planning code, Connection code, Metering system code, Operational code (operational planning, ancillary and system services, defense plans, power system management and control) and access code including services and relations to the electricity market, General provisions and document templates)

3.  Consultant support during the grid code acceptance process in National Regulatory Agency.

The following activities have been performed:

• Consultant services

Objective of the connection study is to analyze all possible connection variants and to determine optimal point of common coupling (PCC) between the WPP Krnovo and transmission network, taking into account valid transmission network development plan and grid connection code of Montenegro. Analyses of the optimal PCC between the WPP Krnovo and transmission network have been performed in accordance with the principle to fit the PCC as much as possible into the valid transmission network development plan in order to minimize the total investment costs of the connection infrastructure.

In order to verify whether WPP Krnovo connection terms are complying with the Montenegrin grid connection code rules and to define corresponding measures in the case of non-compliance, the following analyses have been performed:

- Load flow analyses – network element loadings, security N-1 assesment, power losses, voltage stability and reactive power control;

- Short circuit analyses;

- Voltage flickers emission analyses (power quality);

- Impact of intermittent WPP Krnovo production on EPS of Montenegro (secondary and tertiary reserve);

- Dynamic stability – fault ride through capability, mid-term stability assessment and small signal stability analyses.


The following activities have been performed:

·       Optimal PCC analyses
·       Load flow analyses
·       Network security assessment
·       Voltage stability and reactive power control analyses
·       Short circuit analyses
·       Voltage flickers analyses
·       System reserve analyses
·       Transient stability analyses
·       Mid-term stability analyses
·       Small signal stability analyses.

Generation surplus projections in Eastern Europe (EE) region and electricity market scenarios in period 2010 – 2020
for: Terna (Italy)
type: Study
finishing date: June 2011
team: Z. Vujasinović – Project Leader, M. Vuković and S. Mijailović – Consultants, T. Martinović, D. Orlić, M. Stojković

The objective of the study is to analyze different scenarios of generation surplus in SEE/EE region and features of electricity market development, as well as to analyze the transmission network evolution in the period under analysis (2008-2020). This Study presents an update of similar Market Studies performed in 2007 and 2009. Special aspect is the evaluation of influence of the world economic crisis to the regional power sector.

- Generation expansion plans/demand forecast and surplus capabilities
- Assessment and evolution of transfer capacities between countries
- Forecast of electricity prices range
- Conclusions and recommendations.


The following activities have been performed:

·  Review of load/generation development
·  Surplus/deficit analysis
·  Load flow, transmission capacities calculation
·  Estimation of electricity prices
·  Conclusions, recommendations, Final Report.

1. To define the transmission network development plan, by the year 2020. and to determine guidelines for development in 2025
2. To justify the implementation of the proposed plan from the standpoint of technical and economic criteria.
   

1. View current status EPS Montenegro (analysis of electricity consumption in the past, analysis of production and consumption, analysis of the transmission network and the influence of neighbouring electric power systems, analysis of cross-border transmission capacity, losses analysis)
2. Consumption forecast (till 2020, with the vision of the 2025) and prognosis of load by existing and new nodes
3. Development of a network perspective (planning methodology and criteria, defining a new plant by year of entry into operation for the period 2010-2020 years, with guidelines for 2025, the respected age of existing equipment and the reasonableness of the formation of different configurations of the abandonment of the existing or replacement worn elements, based on all testing and analysis suggest the best techno-economical development of variants to the given investment plan).

HVDC Italy-Montenegro: Update of Grid Analysis
for: Terna (Italy)
type: Feasibility Study
finishing date: March 2011
team: P. Mikša and Z.Vujasinović – Project managers, T. Martinović – Task leader

Main objective of this study is to review current and future development stages of transmission network in SEE, and to further evaluate feasibility of new under sea HVDC interconnection between Italy and Montenegro – MONITA and to perform selection of equipment for installation. HVDC submarine cable will have capacity 1000 MW and connection points will be Villa Nova (Italy) and Lastva (Montenegro).

Activities on realization of project “under sea HVDC interconnection between Italy and Montenegro” started in the end of 2007, and at the end of 2010 the contract between Italy and Montenegro is signed to realize this large and significant project. Installation of HVDC connection to Italy will have large influence on region as whole, which enlarges significance of detailed analyses of influence of this particular installation. It is expected that connection between Italy and Montenegro will significantly increase level of electricity exchanges and trade, as well as level of investment in transmission network to support these new electricity market opportunities.

The following activities have been performed:

• Data collection and analyses
• Load flow and contingency analyses
• Fault level analyses
• Equipment adequacy analyses
• Voltage profile and stability analyses
• Dynamic stability analyses.

• Review of current control practice and Grid code of Montenegro
• Analysis of wind data and determination of possible locations of new WPPs;
• Analysis of wind penetration in the electric power system of Montenegro for expected (real) topology and characteristic regimes in 2015 and 2020;

• Identification of any limitations on wind power plant penetration.