Résumé de EPC2000 Art 123(2) pour la décision T0532/20 du 08.02.2023

See also abstract under Article 13(2) RPBA 2020. In T 532/20, the board held that claim 1 as granted defined subject-matter that extended beyond the content of the application as originally filed. This concerned in essence the feature that the generator remained connected to and synchronised with the grid during a low-voltage event of less than 50%. As argued by the appellants (opponents) and the intervener, a skilled person was therefore faced with new information that a continuing connection and synchronisation of the generator with the power grid even at voltage drops to less than 50% of the rated voltage, could be achieved by a UPS-powered blade pitch control system and turbine controller alone. The board was not convinced by the arguments of the respondent (patent proprietor). Rather than identifying a direct and unambiguous original disclosure, the respondent argued that precisely those amendments that were added to the subject-matter of original claims 1 and 3 had been implicitly part of these claims from the beginning. However, the board explained that, on any objective reading, neither claim 1 nor claim 3 as originally filed specified that the claimed generators were capable of low- voltage ride through or that they remained connected and synchronised during a low- voltage event of any size. The respondent argued furthermore that the appellants and the board in reality raised an objection of missing essential features against claims 1 and 3 of the main request in the guise of an objection of added subject-matter. The board held that this was not correct. Claim 1 was amended so as to be limited - only after the amendment - to a generator that was capable of remaining connected and synchronised during low voltages of under 50% of rated voltage. However, the measures that were originally disclosed to be necessary to achieve that result, in particular a protective circuit for the inverters and a blade pitch system controlled so as not to trip the generator, were not added to the amended claim. The fact that the claimed generator could achieve this technical effect without the originally disclosed corresponding measures represented new information. The respondent also argued that a protective circuit, in particular in the form of a crowbar circuit, was originally disclosed only as an embodiment or an optional feature, reasoning that if an applicant drafted an application by representing a protective circuit as optional, then this represented an original disclosure to the skilled person. This argument did not convince the board. A skilled person did not read an application as a linguist would, but rather on the basis of their technical understanding. The application clearly taught the skilled person that a severe voltage drop at the generator terminals caused high currents in the generator windings, which could damage the semiconductor switches in the inverter. If this happened, the generator could not remain connected and synchronised. The original application did not contain a single technically useful piece of information as to how a severe voltage drop could be accommodated otherwise than with a protective circuit. It also did not contain a single piece of credible disclosure of conditions under which a low-voltage event did not cause excess currents in the generator. In view of this, a skilled person saw beyond the respondent's strategic choice to represent most parts of the disclosure as optional. In this context, it was simply irrelevant how often the words "in one embodiment" were used correctly or not. The respondent also adopted the opposition division's argument from the decision under appeal that generator synchronisation with the power grid and the damage of components were two different problems which were not inextricably linked to each other. A low-voltage event could also be addressed by increasing the capacity in various components such as the motor, generator and/or converter. The board was not convinced by this argument. The variable frequency current produced in the generator was transformed in the converters to the stable grid frequency before being fed to the grid. If the inverter was destroyed, the generator could not remain connected and synchronised to the grid. Hence protecting the inverter was a prerequisite for, and hence inextricably linked with, the claimed technical effect expressed in claim 1 after the amendment.