SU450296A2 - Starting device for autonomous inverter - Google Patents

Description

The main auth. No. 250278 i izvesgno device for starting an autonomous inverter containing a chain of series-connected charging resistance, shunt other capacitor, and a thyristor switch connected to the input terminals of the inverter bridge However, this device does not provide a reliable start of the inverter with a low value, since it sets only the initial current in the smoothing choke of the inverter and does not specify the initial charge on the commutating capacitors. The proposed device differs from the known one in that the thyristor switch is shunted by a reverse current thyristor. The drawing shows the basic scheme of the described device. The device contains a chain of series-connected charge resistance I, a thyristor switch 2, extinguishing condensation; mountain 3 and thyristor 4 reverse ka. This chain is connected to the input terminals of an inverter bridge, consisting of controllable gates 5-8, which is connected to a power source through a smoothing choke 9. A switching capacitor 10 and a load II are connected to the output of the inverter. The device operates as follows. Before supplying the control pulses to the gates 5-8 of the Inventor, the control pulse is fed to the thyristor 2. Under the action of the voltage of the power source through the choke 9, the resistance I and the thyristor 2 begins to flow. After some time, the capacitor 5 is charged to the voltage of the polarity indicated in the drawing, and in the choke 9 the current I is determined by the value of the power supply voltage and the resistance

resistor I, then the control pulses are fed to the thyristor of the reverse current and simultaneously to the valves of the inverter bridge. The capacitor 3, discharging the load circuit, charges the switching capacitor 10 by the voltage of the polarity indicated on the line. At the same time, the discharge current of the capacitor 3 extinguishes the rotary switch 2. The current from the power source, which flows earlier through the choke 9 and the resistance I, enters the load circuit, increasing the voltage on the capacitor 10,

Thus, by the time of the first switching of the inverter bridge valves, the voltage on the switching capacitor becomes sufficient to reliably lock them,

SUBJECT OF INVENTION

A device for starting an autonomous inverter in accordance with aut. No. 250278, characterized in that, in order to increase reliability, the thyristor switch is shunted by a reverse current thyristor.

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