PART II OPERATIONAL SECURITY

TITLE 1 OPERATIONAL SECURITY REQUIREMENTS

CHAPTER 1 System states, remedial actions and operational security limits

Article 21 Principles and criteria applicable to remedial actions
1. Each TSO shall apply the following principles when activating and coordinating remedial actions in accordance with Article 23:
(a) for operational security violations ..., a TSO shall design, prepare and activate remedial actions to restore the system to the normal state and to prevent the propagation of the alert or emergency state outside of the TSO's control area from the categories defined in Article 22;
Words in Art. 21(1)(a) omitted (E.W.S.) (31.12.2020) by virtue of The Electricity Network Codes and Guidelines (System Operation and Connection) (Amendment etc.) (EU Exit) Regulations 2019 (S.I. 2019/533), reg. 1(2), Sch. 1 para. 22(2) (as amended by S.I. 2020/1016, regs. 1(2), 6(2)); 2020 c. 1, Sch. 5 para. 1(1)
(b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Art. 21(1)(b) omitted (E.W.S.) (31.12.2020) by virtue of The Electricity Network Codes and Guidelines (System Operation and Connection) (Amendment etc.) (EU Exit) Regulations 2019 (S.I. 2019/533), reg. 1(2), Sch. 1 para. 22(3) (as amended by S.I. 2020/1016, regs. 1(2), 6(2)); 2020 c. 1, Sch. 5 para. 1(1)
2. When selecting the appropriate remedial actions, each TSO shall apply the following criteria:
(a) activate the most effective and economically efficient remedial actions;
(b) activate remedial actions as close as possible to real-time taking into account the expected time of activation and the urgency of the system operation situation they intend to resolve;
(c) consider the risks of failures in applying the available remedial actions and their impact on operational security such as:
(i) the risks of failure or short-circuit caused by topology changes;
(ii) the risks of outages caused by active or reactive power changes on power generating modules or demand facilities; and
(iii) the risks of malfunction caused by equipment behaviour;
(d) give preference to remedial actions which make available the largest cross-zonal capacity for capacity allocation, while satisfying all operational security limits.