SU1548831A1 - Self-excited inverter - Google Patents

Abstract

The invention relates to a converter technique. The goal is to increase efficiency. The device contains a bridge on the thyristors 1 - 4. The main winding of the smoothing throttle 7 is shunted with a series of capacitor 11 and tripping thyristor 10. The cathode of the additional thyristor 12 connected to the main winding tap is connected to the thyristor 10 by the anode and to the thyristor 10. the main winding current is closed through the capacitor 11. With the subsequent switching on of the bridge thyristors and thyristor 12, the capacitor 11 is charged into the load circuit 6. 1 sludge.

Description

the anode is connected to the cathode of the disconnecting power supply 25, the main winding of the choke is 10, the power supply 13 is connected to the input terminals of the inverter.

The inverter works as follows.

The polarity of the voltages on the capacitors in the initial state is shown in the drawing without brackets.

In each odd half-period of the output voltage of an autonomous inverter, thyristors 1, 4 and 12 are included, and in even half-period - thyristors 2,

3 and 12.

Since the voltage on the capacitor 11 is directed toward the EMF of the power supply 13 and toward the voltage on the winding part of the throttle 7 (at the time of switching thyristor pairs 1,

4 and 2, 3), in the steady state, the current through the thyristor 12 in the absence of overvoltages on the output terminals (on the capacitor 5) does not flow, because when the device is turned on, the current flowing through the thyristor 12 charges the capacitor 11 to a value that prevents further his charge. The polarity of the voltage of the capacitor thus charged 11. shown in the drawing without brackets.

In the absence of overvoltages at the output of the autonomous inverter, thyristors 10 and 12 and diode 9 do not unlock and the operation of the circuit does not differ from the operation of a conventional parallel current inverter.

thirty

35

40

45

 50

55

l 7 - thyristor 2 - capacitor 5 thyristor 3 - power supply 13.

By the end of the even half-period, the full voltage of the capacitor 5 corresponds to the polarity shown in the figure without brackets.

Consider the operation of the circuit in case of overvoltage. In this case, switching on and off of thyristors 4 and 2, 3 and changing the polarity of the voltage on the capacitor 5 and load 6 fully correspond to the previously described processes in the absence of

overvoltages. When the instantaneous output voltage of the autonomous inverter exceeds the permissible value Up by an absolute value, the thyristor 10 is turned on and the main winding of the chokes 7 is closed along the main coil of the chokes 7 - thyrior 10 - the capacitor 11 - the main windings of the chokes 7. Voltage sign at the choke is reversed, the working thyristors 1-4 are locked, the output voltage of the autonomous vector begins to decrease.

When the voltage on the capacitor 11 changes polarity to that shown in the drawing in parentheses and reaches the value recalculated through the transformation ratio of the windings 7 and 8 of the power supply 13, is unlocked by each one 9 and the rest of the electromagnetic energy stored in the smoothing choke.

0

five

0

five

0

five

l 7 - thyristor 2 - capacitor 5 - thyristor 3 - power supply 13.

By the end of the even half-period, the polarity of the voltage of the capacitor 5 corresponds to the polarity shown in the figure without brackets.

Consider the operation of the circuit in the presence of overvoltages. In this case, switching on and off of thyristors 1, 4 and 2, 3 and changing the polarity of the voltage on the capacitor 5 and the load 6 fully correspond to the previously described processes in the absence of

overvoltages. When the instantaneous value of the output voltage of the autonomous inverter exceeds the permissible value Up in absolute value, the thyristor 10 is turned on and the main winding of the droplets 7 is closed along the circuit of the main winding of the chokes 7 - the thyristor 10 - of the capacitor 11 - the main winding of the chokes 7. The sign of the voltage on the choke changes On the reverse side, the working thyristors 1-4 are locked, and the output voltage of the autonomous inverter begins to decrease.

When the voltage on the capacitor 11 changes polarity to that shown in the drawing in brackets and reaches the value recalculated through the transformation ratio of the windings 7 and 8 of the emf of the power source 13, the diode 9 is unlocked and the rest of the electromagnetic energy stored in the smoothing choke begins to flow into the power source 13 along the circuit diode 9 - additional winding 8 - power supply 13 - diode 9,

After a short time, determined by the dissipation inductors of windings 7 and 8, the thyristor 10 is locked. The excess electromagnetic energy of the smoothing throttle through diode 9 and the additional winding 8 enters the power source.

The next impulse applied to the pair of thyristors I and 4 (or 2 and 3) is unlocked by the thyristor 12.

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The capacitor 11 is discharged to the load circuit of the autonomous inverter through the power supply source 3 - capacitor 11 - thyristor 12 - thyristor 1 - capacitor 5 - thyristor 4 - power source 13 (when unlocking the thyristors 2 and 3, the discharge of the capacitor is carried out - capacitor 11 - thyristor 12 - winding 7 - thyristor 2 - capacitor 5 - thyristor 3 - power supply 13).

In this case, the diode 9 is locked, and the capacitor 11 is recharged to eg

1548831

0

five

0 5

about

The polarity of which is shown in the drawing without brackets, after which the thyristor 12 is locked.

Claims (1)

Invention Formula A stand-alone inverter containing directly connected to a negative input terminal and a thyristor bridge through the main winding of the smoothing throttle to the positive one, the alternating current leads of which are connected to the output terminals and the switching capacitor, and the secondary winding of the smoothing throttle through the return diode is connected to the input terminals, and the main winding the winding is shunted by a series of capacitors and tripping thyristors connected by an anode to an anode group of thyristors m hundred, and the point of the capacitor and the isolation of the compound of the thyristor anode is connected an additional thyristor, characterized in that, in order to increase efficiency, the basic operation of the smoothing choke is formed with a tap connected to the cathode of auxiliary thyristor.