Transmission System Supply Reliablity and Quality Regulation

TRANSMISSION SYSTEM SUPPLY RELIABLITY AND QUALITY REGULATION

SECTION ONE Objective, Scope, Legal Basis, Definitions and Abbreviations

Objective Article 1- The objective of this Regulation is to set forth the procedures and principles applicable to the transmission system supply reliability and quality requirements to be fulfilled for reliable and low-cost operation of the transmission system and for ensuring delivery of high quality, adequate and low cost energy to consumers.

Scope Article 2- This Regulation covers the design principles, supply quality conditions and operational principles concerning the transmission system, and rules and procedures for generation facility switchyards design to be complied with by TEIAS and transmission system users.

Legal basis Article 3- This Regulation has been issued in compliance with the provisions of the Electricity Market Law no. 4628.

Definitions and Abbreviations Article 4- The terms and abbreviations used in this Regulation shall bear the following meanings; 1. TEIAS: Turkish Electricity Transmission Inc. Co., 2. UCTE: Union for Coordination of Transmission of Electricity, 3. Supply capacity loss: Decrease in supply capacity in electricity generation and transmission systems, 4. Disconnector: The equipment that connects and disconnects the non-loaded electric circuits, 5. Connection point: The site or point where a user connects to the system as per the connection agreements, 6. Busbar: The conductor, where the feeders at the same voltage connected to, 7. Busbar coupling: Connection of two busbars at the same voltage level through breaker, disconnector, and serial reactors when deemed necessary, 8. Primary or (N-1) Constraint: Situtation of tripping of any equipment of transmission system or group of equipments connected to each other due to a fault, 9. Secondary or (N-2) Constraint: Situtation of tripping of 2 seperate equipments of transmission system at the same time due to faults, 10. Crossing: The changing of conductors at points corresponding to nearly 1/3 and 2/3 of the line length in order to equalize the phase impedances of the transmission line, 11. Fluctuating Load: Variable impedance load which lags interrupted current in different amplitudes and distort the waveform of grid voltage, Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. 12. Tripping: Automatic or manual outage of a part of the facility and/or equipment due to maintenance, repair or fault, 13. Feeder: Line or cable outlets which transmit energy to a customer or a customer group from a central busbar, 14. Frequency: Number of cycles stated in Hertz of the alternative current in the system in one second, 15. Transmission circuit: The part of the transmission system between two or more breakers, 16. Transmission equipment: Transmission circuits, busbars and switch equipment installed on the transmission system, 17. Transmission system: Electricity transmission facilities and network, 18. Applicable Legislation: The laws, regulations, communiqués, circulars and Board decisions regarding the electricity market and the licenses of the related legal entities, 19. Breaker: Device used to open/close loaded electricity circuits for maintenance purposes or under fault conditions, 20. Short-circuit power: Highest apparent power occurring in a short-circuited busbar, 21. User: The legal entities engaged in generation activity and/or distribution companies and/or legal persons importing/exporting electricity and/or eligible consumers, 22. Power Line Carrier: An electronic device developed to ensure communication between two or more stations in the high voltage network via high voltage lines, 23. Normal operating condition: Operating condition where voltage, frequency, and line flows are in specified ranges, load demands are met, ancillary services are provided and operation of the system is stable, 24. Automatic generation control: The control system hardware and software which are installed at the National Load Dispatch Center and which set the MW output of generators and send necessary signals to the speed regulators of generation facilities in order to ensure secondary frequency control in case of a generation or demand loss, 25. Serial Capacitor: Capacitor group used for increasing system stability via decreasing of impedance at the line to which serially connected, 26. Serial Reactor: The winding which is used to limit currency at feeder it is connected to, 27. System emergency conditions: Extraordinary system operation conditions which arise upon outage of multiple generation and/or transmission and/or distribution facilities and equipment, 28. Strategic Facilities: Facilities such as military bases and airports, 29. Shunt capacitor: Condenser group generating reactive power and in parallel connection to the system, 30. Shunt reactor: The winding which gets reactive power from line, transformer or busbar it is connected to and which is used for decreasing of voltage level, Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. 31. Thermal capacity: The amount of energy allowed to flow through a circuit under certain circumstances, 32. Facility: Plant and/or equipment set up to perform the activities of generation, transmission or distribution of electricity, 33. Unit: Each generating set which can load and unload independently, and, as for combined cycle power plants, the share of each gas turbine and generator, and the steam turbine and generator connected to the gas turbine and the generator, 34. Generation Facility: Facilities generating electricity, 35. Annual load factor: The rate of the annual actual generation of a unit or generation facility to annual maximum generation of that unit or generation facility, expressed in percentage.

SECTION TWO Transmission System Planning and Design Principles

Planning Principles of the Transmission System Article 5- TEİAŞ plans and develops the transmission system in compliance with the principles and procedures lay down in the applicable legislation.

The transmission system is planned in order to ensure loading of the transmission system under the thermal limits, to ensure not loosing of even a user and in order to avoid island operation of the system, under normal operating conditions, under primary or N-1 constraint and transport of maximum generation of generation facilities to the system conditions, via ensuring the voltage and frequency of the system is kept within the limits described in this Regulation and the Grid Regulation.

In cases of secondary or N-2 constraint conditions, loading or deloading methods may be resorted to in order to avoid system black-out.

The nominal voltage values of the transmission system are 380, 154 and 66 kV. In the basic system design, the system pre-fault planning voltage limits are planned between 370 and 420 kV for 380 kV; between 146 and 162 kV for 154 kV; between 62 and 70 kV for 66 kV. It may be considered between 140 and 170 kV for regions to which 380 kV lines do not reach.

For the relevant planning year, the transmission system is planned in such a manner that the voltage levels will be within the limits described in the fourth paragraph under the condition of loading above 5% of the system peak load.

With the date of commencing of synchronous parallel operation with the UCTE system, 389 kV voltage level is increased to 420 kV.

Step-down power transformers in the interconnection net use the characteristics described in Annex-1.

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. Transmission facilities of users are parts of the transmission system, any kind of transmission investment to these facilities are made by TEİAŞ and related user within the framework of applicable legislation, upon permission of TEİAŞ.

Design Principles of the Transmission System Article 6- The following issues are considered when designing and developing 380 kV and 154 kV transmission system; a) The maximum number of 380 kV feeders to be connected to a substation is designed as seven and, and the maximum number of 154 kV feeders as fourteen. However, higher number of feeder connections can be made on the condition that short circuit current levels remain within limits and taking into consideration the economic condition and system security.

b) The transmission system is designed in such a way that it can bear adequate capacity under primary or N-1 constraint circumstances when hydro-electric and thermal units are operating in full capacity at the same time.

c) The 380 kV and 154 kV portions of the 380 kV substations is designed in the order of two main and one transfer busbars, with transfer and coupling feeder or with transfer-coupling feeder with single breaker.

d) New 380/154 kV substations is designed as 4x250 MVA or 6x250 MVA, and under specific circumstances, as 8x250 MVA transformer.

e) The 154 kV portion of 154 kV substations is designed in the order of two main busbars, with coupling feeder. 154 kV substations are designed in the order of two main busbars to enable “regional islanding” or “leveled” grid operation.

f) New substations connecting the 154 kV system to the distribution system shall be designed as 2x100 MVA, 3x100, 4x100 MVA transformer order. Although the design at new substations is made on the basis of 100 MVA transformers, but lower capacity transformers can be used in due regard to lower loads. Capacity increase is planned for cases where the actual loads of transformers reach 70 % of their installed capacity. The number of 34.5 kV line feeders for 100 MVA transformers is designed as 8+1, one being used for strategic loads.

The neutral point of secondary winding of a transformer connecting the 154 kV system to a distribution system is earthed through 1000 A resistance.

g) Arc furnace facilities are connected at appropriate voltage level depending on the power and location where it will be installed and its power, in order to restrict flicker severity, harmonics and sudden voltage changes. Flicker severity, harmonics and sudden voltage changes are measured by remote accessible, sealable metering systems, which will be in continuous operation.

h) In cases where direct transformation is necessary, the transformers connecting the 380 kV system to a distribution system are designed as 380/33.6 kV and 125 MVA. These star-triangle connected transformers with 380/33.6 kV voltage level are earthed using earthing transformer.

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. i) Three-phase fluctuating loads and loads supplied with single-phase alternative current are connected to points where the short circuit power of the system is high enough. The step-down transformers supplying single-phase alternative current loads are connected between different phase pairs in order to minimize voltage imbalances. In order to minimize voltage imbalances, step-down transformers supplying single-phase alternative current loads are connected to the system as three phases, at the points where system short circuit power is not high enough.

j) The transmission system is designed in such a way that it will be resistant to switch-on current in 50 kA and 31.5 kA three-phase symmetric fault, for 380 kV switch equipment and 154 kV switch equipment, respectively. Short circuit fault currents are limited with 16 kA at 33 kV voltage level.

k) In 380 kV and 154 kV system designs, earth fault factor is accepted as 1.4, unless otherwise indicated by TEIAS. In cases where a special earthing infrastructure is required for connections to the transmission system, the technical requirements to be fulfilled for earthing and the results of analyses to be conducted upon rises in voltage is communicated to the user by TEIAS before connection. The high voltage windings of transformers whose primary side is 66 kV and above are designed as star-connected, allowing earthing connection at the star point. Minimum 120 mm2 copper shall be used for substation primary earthing line. Earthing connections are made using the connection system approved by TEIAS. At substations where short circuit power is high, the neutral point of the secondary side of power transformers is earthed through a neutral resistance or neutral reactor in order to restrict phase-earth fault currents. In addition, under some specific conditions, neutral earthing transformer is installed at the distribution busbar. The neutral points of the primary and secondary windings of 380 kV and 154 kV star-star-connected autotransformers are earthed directly and their neutral points are connected to the earthing network of the switch center. The neutral point of the primary windings of star-triangle transformers connecting 380 kV system to a distribution system is earthed directly and the secondary winding is earthed through the earthing transformer. The neutral point of the primary windings of star-star non-reverse wounded transformers connecting the 154 kV system to a distribution system is earthed directly, while the neutral point of the secondary winding is through the earthing resistance.

l) The neutral points of the windings on the transmission side of units connected to the transmission system are earthed directly. In regions where generation is intensive, the neutral point of the winding of the unit transformer on the transmission side is insulated fully in order to restrict single-phase fault currents in the 154 kV system.

m) The neutral point of generators is earthed through the resistance. Generator earthing resistance is calculated, determined and installed depending on the condition that resistive and capacitive components of the phase earth fault current are equal. The neutral point of generators is not fully insulated and is not earthed directly or through reactance.

n) Serial connected capacitors are used for reducing the serial inductive reactance of 380 kV transmission lines, when necessary.

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. o) Shunt compensation is ensured through shunt reactors and shunt capacitors in the system. Shunt reactors are designed in a manner to be connected both to line and busbar. This approach is valid for connections to ends of radial transmission lines. Shunt reactors are installed at the reverse wounded windings of 380/154 kV autotransformers; and shunt capacitors at the busbars on the secondary side of transformers at 154 kV substations. The standard capacities of shunt reactors installed at the 380 kV system are 60 MVAr, 80 MVAr, 100 MVAr, 120 MVAr and 150 MVAr. The standard capacities of shunt reactors installed at the 154 kV system are 5 MVAr, 10 MVAr and 20 MVAr. Shunt reactors are designed in such a way that they will operate continuously at 420 kV and 170 kV. 5 MVAr, 10 MVAr and 2x10 MVAr shunt capacitor groups are installed at the busbar on the secondary side of 25 MVA, 50 MVA, 100 MVA and 125 MVA transformers at 380 kV and 154 kV substations in order to correct power factor. Shunt capacitors are installed in such a way that they will not exceed 20 % of the transformer capacity and in the form of two capacitor groups that are connected to different feeders when necessary.

p) In selecting the routes and substation locations of transmission lines; all technical, economical, social and environmental protection issues as well as applicable legislation are considered. The transmission system master plans are ensured that they are covered by the settlement plans of the relevant municipality. Compliance with these master plans is overviewed. Expropriation of transmission lines is finalized within the minimum possible time period. Low-capacity transmission lines are replaced by high-capacity multi-circuit transmission lines on the same route at settlement units with high population density and at industrial zone considering the conditions. Substations are planned and installed with the necessary infrastructure that enables remote no-man operation, and in compliance with international design, installation, manufacturing and performance standards developed, approved and used for electricity system facility and equipment.

r) A complete three phase crossing is made along the line for 380 kV transmission lines longer than 120 km as indicated in Annex 2 of this Regulation. The same approach is valid for 154 kV transmission lines longer than 45 km.

s) 380 kV transmission lines aree installed using single-circuit poles and steel- reinforced aluminum conductors (ACSR) with standard 954 MCM Cardinal (546 mm 2 ) and 1272 MCM Pheasant (726 mm 2 ) section, in the form of double or triple beams in each phase. 380 kV lines having the abovementioned characteristics are used on standard single-circuit poles designed on the basis of appropriate climate and line profile/mechanical loading conditions. Multiple circuits can be used on a single pole in exceptional cases, such as intense settlement areas. In exceptional cases or cases which require additional security measures such as routes above an altitude of 1600 m, which may involve extreme ice load, electrically equivalent single conductors with 2027 mm2 section may be installed on poles specifically designed for limited distances between 1 and 20 km, instead of two or three conductors on each beam. Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. In dense settlement areas where overhead line routes cannot be ensured, XLPE copper conductor underground cables with 2000 mm2 section are installed. The thermal capacities and thresholds of conductors used in energy flow planning in the 380 kV transmission system are given in Annex-3.

t) 154 kV transmission lines are installed using standard 468 mm 2 795 MCM Drake, 546 mm 2 954 MCM Cardinal and 726 mm 2 1272 MCM Pheasant steel reinforced aluminum conductor (ACSR) and single or double circuit poles. 154 kV lines generally contain a conductor in every phase. In order to raise the capacity of transmission lines in very high demand regions, 154 kV double circuit strategic short lines with double beam cardinal conductor are installed. In dense settlement areas where overhead line routes cannot be ensured, 154 kV XLPE copper conductor underground cables with 630 mm 2 or 1000 mm 2 section are installed. The conductor thermal capacities and thresholds as well as the types and capacities of underground power cables used for energy flow planning in 154 kV transmission system are given in Annex-3.

u) In addition to three-phase conductor, galvanized steel earthing wire is installed at the top of poles, in order to protect the transmission line from lightning. In general, two earthing wires are used in single-circuit and double-circuit lines on 380 kV standard poles. 154 kV lines are protected by one or two earthing wires, depending on the pole design. 96 mm2 and 70 mm2 protection conductors are used for 380 and 154 kV lines, respectively, as a standard. Instead of one of the standard steel earthing wires in newly installed transmission lines, 15.2 (0.3) mm in diameter earthing condcutors and optical fibres located in it are used for 380 kV and 154 kV lines. The communication media is installed for voice, data and protection signal communications required for operation of the transmission system and energy management. The communication media may be used for other public and private communication needs, when required. The protection conductors in transmission lines that are in operation are replaced by optical fiber protection conductor when necessary. In order to ensure appropriate insulation levels for the phase conductors of transmission lines, chain-type porcelain, glass or fiber insulators are used.

v) The 380 kV and 154 kV media conditions and system information used in substation system design are given Annex-4. In cases where arrester is used to restrict switching over-voltages, TEIAS and the user exchange information on the technical characteristics of these practices. Understanding on the details of each practice is reached in order to ensure the integrity of the planned system and the harmony of design. Design of substation switchyards are made in compliance with the sample single circuit schemes given in Annex-5.

y) Data and voice communication in the transmission system are carried out through power line carrier and optical fiber communication systems. In addition, Turkish Telecommunication Corporation’s leased communication channels are used when Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. necessary. In order to collect data through SCADA system; Remote Terminal Units (RTUs) are installed at substations and generation facilities. A special telephone system is used for voice communication among the substations of TEIAS, generation facilities and National Load Dispatch Center/Regional Load Dispatch Center.

SECTION THREE Generation Connection Principles

Design Principles of Generation Facility Switchyards Article 7- The following issues are considered in designing and developing of generation facility switchyards: a) Unit main power transformers are installed with minimum 5 step changers when non-loaded and the regulation band is to be  2 x 2.5 %. A regulation band of  8 x 1.25 % is adequate for transformers with step changers when loaded, under normal conditions. b) The connection of generation facilities with total output power less than 1500 MW is made in such a way that all of the generation is transferred to the system in case of a transmission circuit loss or in primary or N-1 constraint case. c) The connection of generation facilities with total output power above 1500 MW is made in such a way that minimum 80 % of generation is transferred to the system in case of the loss of two transmission circuits or in secondary or N-2 constraint case. d) The risk of generation loss to arise in case of the loss of two interrelated transmission lines or in secondary or N-2 constraint case shall not be more than 1200 MW. e) Transmission system and the generation facility switchyards are designed and installed in a manner that generation loss shall not be more than the generation of biggest unit in the system in cases where a transmission circuit or busbar stops operating due to a fault in the aftermath of the planned outage of a single transmission circuit or busbar. f) The maximum length of the overhead line connections of units directly connected to the transmission system shall not be longer than 5 km for units whose annual load factor is equal to or more than 30 %, and shall not be longer than 20 km in other cases. g) The transmission capacity defined for the connection of the generation facility to the transmission system is planned in such a way that, before any fault; 1) the equipment is not loaded above capacity, 2) voltages outside the limits set for normal operating conditions and inadequate voltage regulation possibility are avoided, and 3) system instability is avoided, h) The capacity between a generation facility and the transmission system is also planned by considering the outage of any one of the followings due to a fault: 1) A single transmission circuit, a compensator or another reactive power supplier, 2) Two transmission circuits or a single transmission circuit and another transmission circuit that stopped operating earlier,

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. 3) One of the busbars, 4) A single transmission circuit and a unit that stopped operating earlier, a compensator or another reactive power supplier,

The transmission system is planned in such a way to unsure avoiding of system instability due to faults mentioned in this sub-paragraph.

Demand connections and connections of generation facilities are made in compliance with the sample single circuit schemes given in Annex-6. i) Connection of generation facility based on wind energy is permitted for a capacity up to 5 % of the system short circuit power at the connection point In the evaluation of connection application made for regions where fluctuating loads are intensive, the effect of the existing fluctuating loads at the connection point is also considered. In the case of surpassing the wind velocity some certain limits, connection of generation facility based on wind power having not more than a capacity of system spinning reserve is permitted by considering automatic tripping features of generation facilities based on wind energy, in order to avoid sudden voltage variations and frequency fluctuations in the system. Fault and after-fault performance of generation facilities based on wind energy is designed in compliance with the graph in Annex-7. The power factor of generation facilities based on wind energy having asynchronous wind turbine shall not be less than 0.99 in order to restrict any damage to the system in technical aspects such as reactive energy and voltage. Power factor is raised through appropriate compensation facilities that the user will install.

SECTION FOUR Supply Quality Requirements and Operating Principles

Voltage Article 8- Nominal voltages of the transmission system are 380 kV, 154 kV and 66 kV.

Under normal operating conditions; 380 kV system is operated between 340 kV and 420 kV and the 154 kV transmission system between 140 kV and 170 kV. For the 66 kV and lower transmission system, voltage variation interval is  10 %. Furthermore, voltage levels for the distribution level in the transmission system and for internal demand are 34.5 kV, 33 kV, 31.5 kV, 15.8 kV, 10.5 kV and 6.3 kV.

380 kV and 154 kV systems are planned and operated in accordance with the voltage thresholds given in Annex-8. The operating voltage thresholds are applied as the values prior to changing the unit main transformer step settings after fault, or prior to shunt compensation switching.

Frequency Article 9- The nominal frequency of the system is controlled around 50 Hertz (Hz) between the 49.8-50.2 Hz band by TEIAS. Operating limit shall not be exceeded for a period longer than 10 minutes. Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. The target system frequency for normal system operation and automatic generation control is between 49.95 - 50.05 Hz.

Frequency deviations for various generation and/or demand losses shall not be more than the followings and these limits shall not be exceeded for a period longer than 60 seconds; a)  0.2 Hz in generation or demand changes not exceeding  200 MW, b)  0.5 Hz in generation or demand changes between  200 MW and  600 MW, c)  0.8 Hz in generation or demand changes between  600 MW and  770 MW in peak load.

Generation facilities are designed in compliance with the Grid Regulation by also considering the realization of a constraint more severe than defined in this article, the situation of uncontrolled total or partial black-outs, and the possibility that the system frequency may rise to 52.0 Hz or fall down to 47 Hz.

Current Harmonics Article 10- Acceptable current harmonics limits are defined in Annex-9.

Other criteria defining the quality of electricity are applied as defined in the Grid Regulation.

Compensation of Reactive Energy Article 11- The rate of inductive reactive energy withdrawn by consumers directly connected to the transmission system and distribution licensees at any metering point of the transmission system in each settlement period, to the active energy withdrawn from the system shall not be more than 14 %; and the rate of capacitive reactive energy supplied to the system, to the active energy withdrawn from the system shall not be more than 10 %.

The sanctions applicable when these rates are not complied with at each metering point of the transmission system, are defined in connection and use of system agreements.

The control of these rates is carried out within the framework of applicable legislation.

Constraint Conditions Article 12- Highly probable transmission constraints in the transmission system are; a) Primary or (N-1) constraint, which covers the disintegration of one of the following from the system: 1) A transmission circuit, 2) A unit, 3) One of the connection elements of the generation facility to the transmission system,

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. 4) A shunt compensation unit such as synchronous compensator, static VAr compensator, shunt reactor, capacitor, 5) A serial compensation unit, 6) A transformer unit, 7) An outer interconnection,

b) Secondary or (N-2) constraint, which covers the disintegration of one of the following from the system: 1) A transmission circuit and s second transmission circuit regardless of the first one, 2) A transmission circuit and a transformer unit, 3) A transmission circuit and one of the connection elements of the generation facility to the transmission system, 4) One of the connection elements of the generation facility to the transmission system and a transformer unit, 5) One of the connection elements of the generation facility to the transmission system and a shunt compensation unit, 6) One of the connection elements of the generation facility to the transmission system and a serial compensation unit, 7) A transformer unit and a second transformer unit, 8) A transformer unit and a shunt compensation unit, 9) A shunt compensation unit and a second shunt compensation unit, 10) A transmission circuit and a shunt compensation unit, 11) A unit and a transmission circuit, 12) A unit and a transformer unit, 13) A unit and a second unit, 14) A unit and a shunt compensation unit, 15) A transmission circuit and the serial compensation unit of another line associated with that circuit, 16) A transformer unit and a serial compensation unit, 17) A unit and a serial compensation unit, 18) Double-circuit line on the same pole.

Low-probability transmission constraints in the transmission system cover;

1) Busbar fault, 2) Busbar coupling breaker fault, 3) Breaker fault, 4) Protection system fault,

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. 5) Communication protection channel fault, 6) Unexpected secondary or (N-2) constraint conditions.

Principles of Operation Security

Article 13- System security principles cover necessary measures, precautions and operating principles for the operation of the system under system real-time operation conditions without losing the stability of voltage, frequency and load flows within the defined limits. Monthly, weekly and daily system operating programs are defined considering actual operating conditions, climate changes, planned outages as well as unplanned events that may occur in real-time operation and outage of transmission system, and also events such as unexpected demand and weather conditions. Within the scope of operation security principles; necessary measures required for operation of the system in compliance with the operation time schedules under actual operating conditions.

The transmission system is operated reliably where loss of supply capacity, unacceptable overloading of any of main transmission equipment or inadequate voltage performance reserve and system instability do not exist, as well as under the following failure conditions;

a) A single transmission circuit, a reactive compensator or any other reactive power supplier,

b) In cases where the fault occurs in distant points of the system or subject lines are loaded below their capacities; two transmission circuits or a single transmission circuit and another transmission circuit that earlier stopped operating,

c) One of the busbars, d) A single transmission circuit and a unit that earlier stopped operating, a reactive compensator or other reactive power supplier.

The followings are exempted from the operation principles defined in second paragraph and in case of the occurrence of following situations; in case of primary constraint with due regard to system operating principles, operating rules for secondary constraint may be shifted to provided that such shifting is economically advantageous: a) Situation of opening of circuits and disconnection of substation connections in case of any feeder or line fault at substations consisting of key connected circuits constituting a part of the transmission system. b) Situation of applying the measures taken by TEIAS such as increasing system reserve capacity, establishment of protection systems those enable automatic shut-down of generators, forming of proper alternative operating strategies regarding N-1 and N-2 constraints or reducing load of power flows on transmission equipment by means of increasing hot reserve capacity, in order to reduce risks where increased due to bad weather conditions such as thundering, icing, snowing, snow storming, flooding, strong winding.

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. c) Situation of increased risks for loss or supply or demand. Such kind of an operating regime prevails till weather conditions become convenient and the system made reliable. Under this condition, the first fault leading to primary constraint shall not cause overloading of any transmission equipment, high or low frequency conditions, voltage conditions or system instability.

In cases of faults causing secondary constraints, in order to prevent unacceptable overloading of the main transmission equipment and to prevent demand loss, a new generation schedule is prepared promptly. In case of not implementing the abovementioned schedule, short term demand control is applied as a post-fault measure.

Demand control shall not be applied for economical reasons.

All post-fault measures and their reasons are communicated to the relevant legal entities engaged in generation activity and to eligible consumers who may possibly be affected. In this case, the provisions of the Grid Regulation applicable to cutting demand connection manually in emergency cases, instruction of generation facilities and eligible consumers who may possibly be affected about the renewed generation schedule, and/or emergency case short-term over-load capacities are applied. If agreed earlier with the relevant system operator or legal entity engaged in generation activity and consumers directly connected to the transmission grid and who map possibly be affected, additional post-fault measures not covered by the provisions of the Grid Regulation may also be applied. Following the fault leading to primary or N-1 constraint, necessary measures are taken in order to return to normal operating condition in the least possible time frame.

Operating safety principles and procedures are applied to distribution companies, legal entities engaged in generation activities as directly connected to the transmission system and eligible consumers directly connected to the transmission system. However, specific cases that may be otherwise instructed upon negotiations to protect system integrity may also be exempted from this provision.

SECTION FIVE Notices, Settlement of Disputes, Provisional Articles and Final Provisions

Notices Article 18- All notices to be made pursuant to this Regulation are made in compliance with the Law No. 7201 on Notification.

Settlement of Disputes Article 19- In cases where disputes to arise regarding the enforcement of this Regulation cannot be settled between TEIAS and relevant parties, the Authority are

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail. applied to in written form for the settlement of the dispute. The decision of the Board regarding the dispute is binding for both parties.

Provisional Article 1- Pertaining to the conformity to the Grid Regulation and this Regulation, TEIAS is exempted for three years, by considering the rationale regarding transmission system performance set out in the 10 Year Statement to be presented to the Authority.

Provisional Article 2- For contracts signed with an external electricity system before the publication date of the Law, TEIAS is exempted from the provisions of this Regulation during the contract term.

Provisional Article 3- As from January 1, 2007, the rate of the monthly inductive reactive energy to active energy at each metering point is applied as 25 % and the rate of capacitive reactive energy to active energy is applied as 15 %, for consumers directly connected to the transmission system and distribution licensees.

However, for legal entities in this position, this rate is applied within the framework of the provisions of Article 11 of this Regulation, as from January 1, 2009.

Effectiveness Article 20- This Regulation shall be effective on its publication date.

Enforcement Article 21- This Regulation shall be enforced by TEIAS.

Disclaimer: The English version of the Communıqué Regarding the Principles and Procedures of Financial Settlement in the Electricity Market is intended to assist interested foreign parties. There may be discrepancies between the Turkish and English versions. In case such discrepancies occur, the Turkish version shall prevail.