DEVICE AND METHOD FOR CONTROLLING FREQUENCY CONVERTER INCORPORATING MULTILEVEL VOLTAGE INVERTER Russian patent published in 2006 - IPC H02M5/453 

FIELD: electrical engineering; variable-frequency drives whose motors are coupled with mechanotronic systems.

SUBSTANCE: newly introduced in frequency converter control device are three fiber-optic concentrators which are in phase with motor power units, multilevel inverter output voltage signal shaper, multilevel inverter, signal panel. main control panel, frequency-converter on-line monitoring unit, control interface signal shaper for controlling operation of frequency converter and output current of multilevel voltage inverter, as well as signal logic processing and control unit; outputs of each range of motor power phase units are separately connected to inputs of signal shaper for controlling output voltage of multilevel inverter whose respective outputs are connected to inputs of signal panel whose other inputs are connected, respectively, to signal shaper for controlling frequency converter operation and output current of multilevel voltage inverter and output, to frequency-converter on-line monitoring unit coupled through respective ports with central control computer, control interface, main control panel, and signal logic processing and control unit; each power unit is provided with fiber-optic data connector; all power units of ranges corresponding to motor power phases are connected through their fiber-optic data connector to respective fiber-optic concentrators connected to main control panel; the latter is connected through data buses to signal panel and to signal logic processing and control unit provided with connectors for coupling with process parameter sensor signals and with central control computer. Each power unit has built-in bypass diode bridge whose control input is brought to fiber-optic data connector through matching unit; coupled with the latter are also power unit transistor gates. Proposed control method is characterized in simultaneous supply of signals for driving transistors in conduction in adjacent arms of bridge and controlling thyristors of bypass bridges of defective power unit and two other power units occupying same positions from beginning of respective range in ranges of series-connected power units for shaping output voltages of two other phases of multilevel voltage inverter, as well as detection of this moment of simultaneous supply of signals basing on comparison of data signals arriving from output of each range of power units and respective data signals from each fiber-optic concentrator corresponding to these ranges.

EFFECT: improved and simplified design, enlarged functional capabilities due to intermediate check of control system for condition; enhanced speed and reliability.

3 cl, 9 dwg