SU1677816A1 - Controlled ac-to-ac transformer - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to reduce the mass-size parameters by reducing the number of capacitors of the storage capacitor unit. When unlocking the thyristors 6 of the charge thyristor block, the capacitor of the block 2 of storage capacitors is charged. In the time interval 1 / 2T-3 / 4T, where the T-period of the supply voltage, opens the thyristor 7 of the block 3 of discharge thyristors and the energy of the block 2 is transferred to the L-C-circuit. Due to the operation of the capacitors of the unit 2 in both parts of the period, the goal is achieved. 2 Il.

Description

The invention relates to electrical engineering and can be used as an electrical power supply system for active-inductive consumers, in particular electromagnet magneto-dynamic devices.

The aim of the invention is to reduce the mass and size parameters by reducing the number of capacitors of the storage capacitor unit.

FIG. 1 is a circuit diagram of a converter; an example of the embodiment; in fig. 2 - time diagrams that show his work.

The converter contains a block 1 of charge thyristors, a block 2 of storage capacitors, a block 3 of discharge thyristors, the output of which is connected to the L-C-circuit 4, block 1 contains a choke 5 and anti-parallel connected thyristors 6, block 3 contains two parallel circuits from series-connected thyristor 7 and drossel 8.

The Converter operates as follows. When a positive (negative) half-wave supply voltage is received at its input, the directional thyristor 6 of unit 1 is respectively opened and the capacitor of unit 2 is charged until a voltage is dependent on the control angle of the thyristor 6 of unit 1. The current in the circuit has the form of a half-wave sinusoid. When this current is reached, the zero charge thyristor 6 of unit 1 is locked.

Since the thyristors can be considered as ideal switches, and the leakage current in the storage capacitors is negligible, the charge accumulated in them can be retained for a considerable time. This allows you to get on the load voltage

WITH

Vj h

00 CN

required phase relative to the voltage at the output of the converter, controlling the moment of unlocking respectively the directional thyristor 7 of block 3. In the time interval 1 / 2T (0) -3 / 4T (1 / 4T), where T is the period of the supply voltage, when at the input The device is equipped with the corresponding half-voltage supply voltage, respectively, the directional thyristor 7 of block 3 is unlocked, as a result of which the energy stored by the capacitor of block 2 is transferred to LC circuit 4. , protects the thyristors 7 of block 3 from breakdown and increases the efficiency of the converter.

At the moment of equality of the voltage on the capacitor L-C-circuit 4 and the voltage on the storage capacitor of the unit 2, the previously open thyristor 7 of the unit 3 is closed and the transfer of energy to the L-C circuit 4 is stopped.

The amount of energy for the period transferred to the capacitor circuit 4 is determined by the expression E

0Ci (U2c1-UciocT)

2

 Cl (U ci-UC1ocT)

where Ci is the value of the capacity of the storage capacitors of block 2;

Uci is the voltage up to which the storage capacitors of unit 2 are charged after unlocking the charge thyristors of unit 1;

0 5

0

five

0

five

DCIOCT is the residual voltage on the storage capacitors of unit 2 after transferring the energy stored in them to the L-C circuit 4.

The maximum energy will be transmitted to the L-C-circuit 4 in the case when the pulse unlocking the charge thyristor 6 of unit 1 has a phase T / 4 (3T / 4), which corresponds to the maximum value of the supply voltage.

The diagrams of the processes occurring in the power section of the device are depicted in figure 2. Diagram 9 shows the network voltage, diagrams 10-13 - pulses opening thyristors 6 and thyristors 7, diagram 14 - voltage on the capacitors of block 2, diagram 15 - output voltage.

Claims (1)

Invention Formula Adjustable AC to AC converter containing series-connected leads for connecting the network, a charging thyristor unit, a block of thyristors and an LC circuit, between the output of the charging thyristor unit and a common output point for connecting the network and a free output of the LC circuit storage capacitor unit, characterized in that, in order to reduce the mass and equipment parameters by reducing the number of capacitors of the storage capacitor unit, charge and discharge thyristor blocks Hur made in form anti-parallel connected thyristors, which are points common form input and output terminals of the respective blocks. Phia.1 fig 2