The Motorized Quadristable Commutator 24Vdc (CQM) has the aim to realize automatically and in full safety the optimal adaptation of the HV power circuit of a multi-voltage converter in order to obtain the most high performance possible and to simplify the configuration of the converter.
With this aim it has been studied a configuration of the HV part of the multivoltage converter in order to adapt it to the 4 normalized European voltages.
The HV Switching stage is composed by 2 asymmetric bridges with 3,3kV IGBTs that can operate both in series or in parallel.
The “CQM” has therefore to put automatically in series or in parallel the 2 asymmetric bridges of the HV Switching stage, depending on the REC voltage detected.
The input filter will be opportunely changed according to each of the 4 voltage of the existing catenary.
Also the turns of the secondary of the HV Swiching transformer will be opportunely modified in case of catenary voltage at 16 ⅔ Hz. As the normalized European voltages are 4, also the stable positions of the CQM are 4.
These 4 positions are:
- 3KVcc : series of the 2 bridges + short-circuit of the HV diode bridge;
- 1,5KVcc : parallel of the 2 bridges + short-circuit of the HV diode bridge;
- 1,5KV 50Hz : parallel of the 2 bridges;
- 1KV 16 ⅔ Hz : parallel of the 2 bridges + increase of 50% of the secondary turns.
They are signaled by 4 micro-switches through a cam fixed on the CQM shaft.