METHOD TO CONTROL BIDIRECTIONAL KEYS IN THREE-PHASE THREE-LEVEL SEMICONDUCTOR RECTIFIER WITH CAPACITANCE VOLTAGE DIVIDER Russian patent published in 2013 - IPC H02M7/155 

FIELD: electricity.

SUBSTANCE: rectangular voltage pulses are generated, middles of generated rectangular pulses are synchronised with phase voltages of a supply network by moments of voltages transition via zero, the actual value of the first harmonic of the phase current is measured, the value of the angle δ is calculated according to the expression where: ω - circular frequency of supply grid phase voltage; L - phase inductance of a rectifier; I₁ - actual value of the first harmonic of the input phase current; U₁ - actual value of phase voltage of the supply grid; U*_d - relative mean value of rectifier rectified voltage, generated rectangular pulses are shifted along the phase to the lagging side by the angle δ, and then sent to control inputs of bidirectional keys of a three-phase three-level rectifier.

EFFECT: possibility to generate a permanent mean value of rectified voltage of a three-phase three-level semiconductor rectifier with a capacitance voltage divider in case of phase current value change.

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