Commission Regulation (EU) 2017/2196Dangos y teitl llawn

CHAPTER III U.K. RESTORATION PLAN

SECTION 1 U.K. General provisions

Article 23 U.K. Design of the restoration plan

1. By 18 December 2018, each TSO shall design a restoration plan in consultation with relevant DSOs, SGUs, national regulatory authorities or entities referred to in Article 4(3), neighbouring TSOs and the other TSOs in that synchronous area.

2. When designing its restoration plan, each TSO shall take into account, at least, the following elements:

(a) the behaviour and capabilities of load and generation;

(b) the specific needs of the high priority significant grid users listed pursuant to paragraph (4); and

(c) the characteristics of its network and of the underlying DSOs networks.

3. The restoration plan shall contain at least the following provisions:

(a) the conditions under which the restoration plan is activated, as provided for in Article 25;

(b) restoration plan instructions to be issued by the TSO; and

(c) measures subject to real-time consultation or coordination with identified parties.

4. In particular, the restoration plan shall include the following elements:

(a) a list of the measures to be implemented by the TSO on its installations;

(b) a list of the measures to be implemented by DSOs and of the DSOs responsible for implementing those measures on their installations;

(c) a list of the SGUs responsible for implementing on their installations the measures that result from mandatory requirements set out in Regulations (EU) 2016/631, (EU) 2016/1388 and (EU) 2016/1447 or from national legislation and a list of the measures to be implemented by those SGUs;

(d) the list of high priority significant grid users and the terms and conditions for their disconnection and re-energisation;

(e) a list of substations which are essential for its restoration plan procedures;

(f) the number of power sources in the TSO's control area necessary to re-energise its system with bottom-up re-energisation strategy having black start capability, quick re-synchronisation capability (through houseload operation) and island operation capability; and

(g) the implementation deadlines for each listed measure.

5. The restoration plan shall include at least the following technical and organisational measures specified in Chapter III:

(a) re-energisation procedure, in accordance with Section 2;

(b) frequency management procedure, in accordance with Section 3; and

(c) resynchronisation procedure, in accordance with Section 4.

6. The measures contained in the restoration plan shall comply with the following principles:

(a) their impact on system users shall be minimal;

(b) they shall be economically efficient;

(c) only those measures that are necessary shall be activated; and

(d) they shall not lead the interconnected transmission systems into emergency state or blackout state.

Article 24 U.K. Implementation of the restoration plan

1. By 18 December 2019 each TSO shall implement those measures of its restoration plan that are to be implemented on the transmission system. It shall maintain the implemented measures henceforth.

2. By 18 December 2018 each TSO shall notify the transmission connected DSOs of the measures, including the deadlines for implementation, which are to be implemented on:

(a) the DSO's installations pursuant to Article 23(4); and

(b) the installations of SGUs identified pursuant to Article 23(4) and connected to their distribution systems; and

(c) the installations of restoration service providers connected to their distribution systems; and

(d) the installations of DSOs connected to their distribution systems.

3. By 18 December 2018 each TSO shall notify the SGUs identified pursuant to Article 23(4) and restoration service providers directly connected to its transmission system of the measures that are to be implemented on their installations, including the deadlines for implementation pursuant to point (g) of Article 23(4).

4. When provided for in national legislation, the TSO shall notify directly the SGUs identified pursuant to Article 23(4) and restoration service providers and DSOs connected to distribution systems and shall inform the concerned DSO of this notification.

5. Where a TSO notifies a DSO in accordance with paragraph 2, the DSO shall notify in turn, without delay, the SGUs, restoration service providers and DSOs connected to its distribution system of the measures of the restoration plan which they have to implement on their respective installations, including the deadlines for implementation, pursuant to point (g) of Article 23(4).

6. Each notified DSO, SGUs and restoration service provider shall:

(a) implement the measures notified no later than 12 months from the date of notification;

(b) confirm the implementation of the measures to the notifying system operator, who shall, when different from the TSO, notify the TSO; and

(c) maintain the measures implemented on its installations.

Article 25 U.K. Activation of the restoration plan

1. Each TSO shall activate the procedures of its restoration plan in coordination with the DSOs and SGUs identified pursuant to Article 23(4) and with restoration service providers in the following cases:

(a) when the system is in the emergency state in accordance with the criteria in Article 18(3) of Regulation (EU) 2017/1485, once the system is stabilised following activation of the measures of the system defence plan; or

(b) when the system is in the blackout state in accordance with the criteria in Article 18(4) of Regulation (EU) 2017/1485.

2. During system restoration, each TSO shall identify and monitor:

(a) the extent and borders of the synchronised region or synchronised regions to which its control area belongs;

(b) the TSOs with which it shares a synchronised region or synchronised regions; and

(c) the available active power reserves in its control area.

3. Each DSO and SGU identified pursuant to Article 23(4), as well as each restoration service provider shall execute without undue delay the restoration plan instructions issued by the TSO, pursuant to point (b) of Article 23(3) in accordance with the restoration plan procedures.

4. Each TSO shall activate those procedures of its restoration plan that have a significant cross-border impact in coordination with the impacted TSOs.

SECTION 2 U.K. Re-energisation

Article 26 U.K. Re-energisation procedure

1. The re-energisation procedure of the restoration plan shall contain a set of measures allowing the TSO to apply:

(a) a top-down re-energisation strategy; and

(b) a bottom-up re-energisation strategy.

2. Regarding the bottom-up re-energisation strategy, the re-energisation procedure shall contain at least measures for:

(a) managing voltage and frequency deviations due to re-energisation;

(b) monitoring and managing island operation; and

(c) resynchronising island operation areas.

Article 27 U.K. Activation of the re-energisation procedure

1. When activating the re-energisation procedure, each TSO shall set up the strategy to be applied, taking into account:

(a) the availability of power sources capable of re-energisation in its control area;

(b) the expected duration and risks of possible re-energisation strategies;

(c) the conditions of the power systems;

(d) the conditions of the directly connected systems, including at least the status of interconnectors;

(e) the high priority significant grid users listed pursuant to Article 23(4); and

(f) the possibility to combine top-down and bottom-up re-energisation strategies.

2. When applying a top-down re-energisation strategy, each TSO shall manage the connection of load and generation with the aim to regulate the frequency towards the nominal frequency with a maximum tolerance of the maximum steady-state frequency deviation. Each TSO shall apply the conditions for connection of load and generation defined by the frequency leader, where appointed in accordance with Article 29.

3. When applying a bottom-up re-energisation strategy, each TSO shall manage the connection of load and generation with the aim to regulate the frequency towards the target frequency established in accordance with point (c) of Article 28(3).

4. During re-energisation, the TSO shall, after consultation with DSOs, establish and notify the amount of netted demand to be reconnected on distribution networks. Each DSO shall reconnect the notified amount of netted demand, while respecting the block loading and taking into account the automatic re-connection of load and generation in its network.

5. Each TSO shall inform its neighbouring TSOs on its capability to support a top-down re-energisation strategy.

6. For the activation of a top-down re-energisation strategy, the TSO shall request neighbouring TSOs to support the re-energisation. This support may consist in assistance for active power, in accordance with paragraphs 3 to 5 of Article 21. The requested TSOs shall provide assistance for the re-energisation, unless it would lead their systems to the emergency or blackout states. In this case, the requesting TSO shall use the bottom-up re-energisation strategy.

SECTION 3 U.K. Frequency management

Article 28 U.K. Frequency management procedure

1. The frequency management procedure of the restoration plan shall contain a set of measures aiming at restoring system frequency back to the nominal frequency.

2. Each TSO shall activate its frequency management procedure:

(a) in preparation of the resynchronisation procedure, when a synchronous area is split in several synchronised regions;

(b) in case of frequency deviation in the synchronous area; or

(c) in case of re-energisation.

3. The frequency management procedure shall include at least:

(a) a list of actions regarding the setting of the load-frequency controller before the appointment of frequency leaders;

(b) the appointment of frequency leaders;

(c) the establishment of target frequency in case of bottom-up re-energisation strategy;

(d) frequency management after frequency deviation; and

(e) frequency management after synchronous area split.

(f) the determination of the amount of load and generation to be reconnected, taking into account the available active power reserves within the synchronised region in order to avoid major frequency deviations.

Article 29 U.K. Appointment of a frequency leader

1. During system restoration, when a synchronous area is split in several synchronised regions, the TSOs of each synchronised region shall appoint a frequency leader, in accordance with paragraph 3.

2. During system restoration, when a synchronous area is not split but the system frequency exceeds the frequency limits for the alert state as defined in Article 18(2) of Regulation (EU) 2017/1485, all TSOs of the synchronous area shall appoint a frequency leader, in accordance with paragraph 3.

3. The TSO with the highest real-time estimated K-factor shall be appointed as the frequency leader, unless the TSOs of the synchronised region, or of the synchronous area, agree to appoint another TSO as the frequency leader. In that case, the TSOs of the synchronised region, or of the synchronous area, shall consider the following criteria:

(a) the amount of available active power reserves and especially frequency restoration reserves;

(b) the capacities available on interconnectors;

(c) the availability of frequency measurements of TSOs of the synchronised region or of the synchronous area; and

(d) the availability of measurements on critical elements within the synchronised region or the synchronous area.

4. Notwithstanding paragraph 3, where the size of the synchronous area concerned and the real time situation allow it, the TSOs of the synchronous area may appoint a predetermined frequency leader.

5. The TSO appointed as frequency leader pursuant to paragraphs 1 and 2 shall inform the other TSOs of the synchronous area of its appointment without delay.

6. The appointed frequency leader shall act as such until:

(a) another frequency leader is appointed for its synchronised region;

(b) a new frequency leader is appointed as the result of resynchronisation of its synchronised region with another synchronised region; or

(c) the synchronous area has been completely resynchronised, the system frequency is within the standard frequency range and the LFC operated by each TSO of the synchronous area is back to its normal operating mode in accordance with Article 18(1) of Regulation (EU) 2017/1485.

Article 30 U.K. Frequency management after frequency deviation

1. During system restoration, when a frequency leader has been appointed pursuant to Article 29(3), the TSOs of the synchronous area, other than the frequency leader, shall as a first measure suspend the manual activation of frequency restoration reserves and replacement reserves.

2. The frequency leader shall establish, after consultation with the other TSOs of the synchronous area, the operating mode to be applied on the LFC operated by each TSO of the synchronous area.

3. The frequency leader shall manage the manual activation of frequency restoration reserves and replacement reserves within the synchronous area, aiming at regulating the frequency of the synchronous area towards the nominal frequency and taking into account the operational security limits defined pursuant to Article 25 of Regulation (EU) 2017/1485. Upon request, each TSO of the synchronous area shall support the frequency leader.

Article 31 U.K. Frequency management after synchronous area split

1. During system restoration, when a frequency leader has been appointed pursuant to Article 29(3), the TSOs of each synchronised region, with the exception of the frequency leader, shall as a first measure suspend the manual activation of frequency restoration reserves and replacement reserves.

2. The frequency leader shall establish, after consultation with the other TSOs of the synchronised region, the operating mode to be applied on the LFC operated by each TSO of the synchronised region.

3. The frequency leader shall manage the manual activation of frequency restoration reserves and replacement reserves within the synchronised region, aiming at regulating the frequency of the synchronised region towards the target frequency established by the resynchronisation leader, if any, pursuant to point (a) of Article 34(1) and taking into account the operational security limits set out pursuant to Article 25 of Regulation (EU) 2017/1485. When no resynchronisation leader is appointed for the synchronised region, the frequency leader shall aim at regulating the frequency towards the nominal frequency. Upon request, each TSO of the synchronised region shall support the frequency leader.

SECTION 4 U.K. Resynchronisation

Article 32 U.K. Resynchronisation procedure

The resynchronisation procedure of the restoration plan shall include, at least:

(a)

the appointment of a resynchronisation leader;

(b)

the measures allowing the TSO to apply a resynchronisation strategy; and

(c)

the maximum limits for phase angle, frequency and voltage differences for connecting lines.

Article 33 U.K. Appointment of a resynchronisation leader

1. During system restoration, when two synchronised regions can be resynchronised without endangering the operational security of the transmission systems, the frequency leaders of these synchronised regions shall appoint a resynchronisation leader in consultation with at least the TSO(s) identified as the potential resynchronisation leader and in accordance with paragraph 2. Each frequency leader shall inform without delay the TSOs from its synchronised region of the appointed resynchronisation leader.

2. For each pair of synchronised regions to be resynchronised, the resynchronisation leader shall be the TSO that:

(a) has in operation at least one substation equipped with a parallel switching device on the border between the two synchronised regions to be resynchronised;

(b) has access to the frequency measurements from both synchronised regions;

(c) has access to the voltage measurements on the substations between which potential resynchronisation points are located; and

(d) is able to control the voltage of potential resynchronisation points.

3. Where more than one TSO fulfils the criteria under paragraph 2, the TSO with the highest number of potential resynchronisation points between the two synchronised regions shall be appointed as the resynchronisation leader, unless the frequency leaders of the two synchronised regions agree to appoint another TSO as resynchronisation leader.

4. The appointed resynchronisation leader shall act as such until:

(a) another resynchronisation leader is appointed for the two synchronised regions; or

(b) the two synchronised regions have been resynchronised, and all the steps in Article 34 have been completed.

Article 34 U.K. Resynchronisation strategy

1. Prior to the resynchronisation, the resynchronisation leader shall:

(a) establish, in accordance with the maximum limits referred to in Article 32:

(i)

the target value of the frequency for resynchronisation;

(ii)

the maximum frequency difference between the two synchronised regions;

(iii)

the maximum active and reactive power exchange; and

(iv)

the operating mode to be applied on the LFC;

(b) select the resynchronisation point, taking into account the operational security limits in the synchronised regions;

(c) establish and prepare all necessary actions for the resynchronisation of the two synchronised regions at the resynchronisation point;

(d) establish and prepare a subsequent set of actions to create additional connections between the synchronised regions; and

(e) assess the readiness of the synchronised regions for resynchronisation, taking into account the conditions set out in point (a).

2. When carrying out the tasks enumerated in paragraph 1, the resynchronisation leader shall consult the frequency leaders of the involved synchronised regions and, for the tasks listed in points (b) to (e), it shall also consult the TSOs operating the substations used for resynchronisation.

3. Each frequency leader shall inform the TSOs within its synchronised region of the planned resynchronisation without undue delay.

4. When all conditions established in accordance with point (a) of paragraph 1 are fulfilled, the resynchronisation leader shall execute the resynchronisation by activating the actions established in accordance with point (c) and (d) of paragraph 1.