Analysis TED/749/2020

21 Sep 2020

This ministerial order is related to the Spanish RD 647/2020, Real Decreto 647/2020 (hereinafter RD), of July 7th, which regulates necessary aspects for the implementation of the grid connection codes of certain electrical installations. The scope of application and definitions are the ones of the RD.

The objective of this document TED/749/2020, hereinafter OM, is to develop the technical requirements that are not fully defined in the regulations: (EU) 2016/631 of requirements on generators Annex I of the OM, (EU) 2016/1388 of OM Annex II demand facilities and (EU) 2016/1447 of OM high voltage systems, Annex III of the OM.

Spain's Transmission System Operator (in Spanish Red Eléctrica de España or REE) and AELEC (Electrical Energy Enterprises Association, in Spanish Asociación de Empresas de Energía Eléctrica) sent proposals for the definition of the mentioned technical requirements in May 2018, which have been approved by this OM.

The differences between the submitted drafts and the published OM are:

  • The frequency requirements are identical to the aforementioned REE and AELEC proposal except in:
    • Response time (1.3 of Annex I of OM). The possibility of agreeing longer response times by agreement with the system operator is included whenever it is due to physical limitations of the use.
    • Capacity and active power control range of (1.6 of Annex I of OM). The times to stop the power output are defined again by modifying them for the MPE type B and for the MGE types B, C and D.
    • Response time (1.7 of Annex I of OM). The possibility of agreeing longer response times by agreement with the system operator is included whenever it is due to physical limitations of the use
  • The voltage requirements are identical to the aforementioned REE and AELEC proposal except in:
    • It includes the disconnection times for MGE type D connected to a radial distribution network with a voltage level below 110kV, see table 4.
    • Disconnection times are included for MGE types B and C connected to a radial distribution network with a voltage level below 110kV, see table 5.
    • Requirements for synchronous electricity modules types B and C are included. See Figure 7.
    • The fast injection control is applicable for MPE type B, C and D.
    • For the invers sequence current of wind MPE with doubly fed generation technology the response is allowed to be the natural response of the technology.
    • The response time of the current injection / absorption is modified, going from 30 ms to ti+tr≤150ms.
    • Stabilization time range band changes from 5% to + 20% and -10%.
    • Requirements for MPE types B and C are included. See Figure 12.
    • Requirements for transient overvoltages of type A MPE are included. See table 6.
  • The robustness requirements are identical to the aforementioned REE and AELEC proposal except in:
    • It is included that if the residual voltage at the low voltage connection point does not drop below 0.5 p.u. and the primary resource allows it, the MPE must reach 95% of the power (prior to the disturbance) in a time less than 1 second once the voltage reaches or exceeds 0.85 pu, and 100% of the power (prior to the disturbance) in less than 2 additional seconds.
    • It is included in the ability to withstand phase jumps in MPE connected to the distribution network, the characteristics of disconnection, reconnection out of synchronism and anti-islanding protection without any damage.
    • Includes requirements for MPE type B, C or D not connected to the transmission grid, to operate stably against temporary over voltages. See Figure 20.
    • The limitation of the continuous component injection for type A is included, which must be less than 0.5% of the nominal current.
    • The requirements of the protection schemes and their settings for MGE type B, C and D not connected to the transmission grid are included. See section 5.4.