초록 ▼

In an inverter device comprising an inverter bridge connected across a DC source, an auxiliary thyristor bridge connected to AC terminals of the inverter bridge, a condenser connected across cathode and anode electrodes of the auxiliary thyristor bridge which acts as a first switching circuit for ch

In an inverter device comprising an inverter bridge connected across a DC source, an auxiliary thyristor bridge connected to AC terminals of the inverter bridge, a condenser connected across cathode and anode electrodes of the auxiliary thyristor bridge which acts as a first switching circuit for charging and discharging the condenser and a second switching circuit including choppers for connecting anode and cathode electrodes of the auxiliary thyristor bridge across the DC source, there is provided a control method which comprises the steps of comparing voltage of the condenser with a reference voltage, controlling respective switching circuits so as to effect commutation of the inverter bridge in a direction to charge the condenser when the voltage thereof is lower than the respective voltage, controlling respective switching circuits so as to effect commutation of the inverter bridge in a direction to discharge the condenser when the voltage thereof is higher than the reference voltage thereby controlling the condenser voltage in accordance with the reference voltage. According to a modification the conduction times of the second switching circuit and the auxiliary thyristor bridge are varied in accordance with the condenser voltage.

대표청구항 ▼

A method of controlling an inverter device comprising an inverter bridge connected across a direct current source, an auxiliary thyristor bridge connected to AC output terminals of said inverter bridge, a condenser connected across cathode and anode electrodes of said auxiliary thyristor bridge whic

A method of controlling an inverter device comprising an inverter bridge connected across a direct current source, an auxiliary thyristor bridge connected to AC output terminals of said inverter bridge, a condenser connected across cathode and anode electrodes of said auxiliary thyristor bridge which acts as a first switching circuit for charging and discharging said condenser, and a second switching circuit for connecting cathode and anode electrodes of said auxiliary thyristor bridge across said DC source, said method comprising the steps of comparing voltage of said condenser with a reference voltage, controlling said respective switching circuits so as to effect commutations of said inverter bridge in a direction to charge said condenser when said condenser voltage is lower than said reference voltage, setting a predetermined delay time corresponding to a commutation initial delay for said inverter bridge at the time of charging said condenser so that said commutation will be delayed during discharge of said condenser, controlling said respective switching circuit, so as to effect commutation of said inverter bridge in a direction to discharge said condenser when said condenser voltage is higher than said reference voltage thereby controlling said condenser voltage in accordance with said reference voltage.