Renault's Daniel Ricciardo was disqualified from the qualifying results after it was found his car exceeded the MGU-K power flow limit during his second flying lap in Q1.
The MGU-K is the kinetic DC motor that uses electricity to accelerate the car along with the power delivered from the internal combustion engine. The energy exchange between the engine and the MGU-K motor is limited to 120kW. Energy flow between batteries and MGU-K is limited to 4MJ/lap from batteries to MGU-K, en 2MJ/lap the other way around.
The MGU-K itself is limited to 50000rpm and 200Nm torque.
"The Stewards heard from the FIA Technical Delegate and team representatives including the team manager and two of the engineers responsible.
"It was established in the hearing, beyond any doubt in the opinion of the Stewards, that the competitor exceeded the MGU-K power flow limit permitted under Appendix 3, per Article 5.2.2 of the 2019 Formula One Technical Regulations.
"The method by which this limit is regulated is well known and understood by the teams. Neither the fact that the car had exceeded the limit nor the methodology by which it is policed was disputed by the team."
The technical regulations specify that electrical DC measurements are used to verify that the energy and power requirements are being respected. A fixed efficiency correction of 0.95 is used to monitor the maximum MGU‐K power.
"The team’s defense rested on two points. First, that the excess was very small and offered no measurable benefit. Second, that the excess occurred during the second fastest lap during Q1. The team explained to the Stewards how they believe the excess occurred, however the Stewards consider this information to be confidential to the team, and not relevant to this decision.
"Notwithstanding the team’s arguments, the Stewards take note of the very clear wording of Article 1.2.2 ISC, which states that “If an Automobile is found not to comply with the applicable technical regulations, it shall be no defense to claim that no performance advantage was obtained”.
"In coming to this decision the Stewards referred to longstanding precedents regarding technical infringements and the penalty which has been consistently applied is disqualification, and which does not consider when or if an advantage was gained. This principle has been very clearly affirmed by the International Court of Appeal."
The Stewards therefore disqualified Car 3 from the results of Qualifying, meaning Renault had to seek permission to the stewards to still allow Ricciardo to start the race. In response to this request, the stewards have then granted Ricciardo to start the race from the back of the grid.
Renault on their behalf decided to fit a 4th new motor generator unit - kinetic (MGU-K) and 4th control electronics (CE) to the car. This could be done at no penalty, as the required 10-place grid drop is meaningless in Ricciardo's current situation.