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Motorized Quadristable Commutator CQM

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:

  1. 3KVcc : series of the 2 bridges + short-circuit of the HV diode bridge;
  2. 1,5KVcc :  parallel of the 2 bridges + short-circuit of the HV diode bridge;
  3. 1,5KV 50Hz  :  parallel of the 2 bridges;
  4. 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.