SU855901A1 - Unipolar current pulse train source - Google Patents

Description

one

The invention relates to a converter technique and can be applied in mechanical engineering with electrochemical and. electrochemical-dimensional metal processing as a pulsed power source.

Pulsed power sources used in electrophysical methods of metal processing, based on technological requirements, should provide unipolar current pulses with an amplitude of up to several thousand amperes with an adjustable voltage across the electrode gap.

A source of packets of unipolar current pulses is known, which contains a serial single-phase inverter with a switching commutator connected to a power source through a controlled valve 11.

However, when using this source, in order to obtain unipolar current pulses with an amplitude of several thousand amperes, a large number of thyristors or inverter cells operating on a common load with parallel operation are required to be connected in parallel, which increases the size

sources and limits their scope. The frequency cftoco6 control in these circuits is ineffective and is carried out only by changing the duty cycle of the current pulses.

The closest to the invention is a source of packets of unipolar current pulses containing a series-connected direct current source, a choke and a bridge thyristor inverter with a switching diagonal LC10 circuit R and reverse diodes LC10, as well as a load included in the diagonal of a direct current diode bridge {2 .

Claims (2)

However, the electrophysical methods of metal processing require obtaining unipolar current pulses with an amplitude of several thousand amperes. The use of this device to obtain large currents is possible using parallel connection of inverter devices to a common load. In addition, the load voltage varies depending on the type of treatment. Thus, electrochemical dimensional processing is carried out at a lower voltage across the electrode gap than 38 electroerosive processing. Transformer switching on the load in the inverter in the case of electrochemical processing provides the current strength with decreasing voltage to the required level, but does not allow smoothly adjusting the a1 the current pulse and the voltage during the process. The purpose of the invention is to increase the amplitude of the pulses of polar impulses and the regulation of the voltage level. This goal is achieved by supplying a packet of unipolar current pulses containing a series-connected direct current source, choke and bridge type inverter with a switching circuit in the diagonal LC and reverse diodes, as well as a load included in the diagonal current diode bridge, two capacitors and two throttles are introduced, and two capacitors and a voltage regulator are connected in series to the diagonal terminals of the alternating current of the diode bridge, the common point of these capacitors is connected through A second choke to one group of thyristors of a bridge thyristor inverter, for example, anodic, another group of thyristors of a bridge thyristor inverter, for example, a cathode, is connected to a diode bridge diode group of the same name, and another diode bridge group, for example, an anode diode, is connected to the same group of reverse thyristor diode diodes inverter. The drawing shows a diagram of the source of packets of unipolar current pulses. The device contains a source of direct current 1 to which a bridge thyristor inverter 3 is connected via a choke 2 with a switching LC circuit consisting of a capacitor 4 and a drosel 5, a bridge thyristor schertor consisting of thyristors 6-9 and reverse diodes 10-13 , the load 14 is connected by one and the terminals with the minus of the source of direct current 1, is included in the diagonal of the direct current of the diode bridge consisting of diodes 15-18, the diagonal of the alternating current of which is connected to a series circuit consisting of droplets 19 and capacitors 20 and 21, cat The aperture is connected to the choke 22, and forms an oscillating circuit 23 with a load connected through a diode bridge. The source of packets of unipolar current pulses works as follows. When the thyristors of the bridge thyristor inverter 3 are turned on, a current ij flows through a circuit formed by a bridge thyristor inverter 3, a nucleus 22 and an oscillating circuit 23, whose frequency corresponds to the resonant frequency of the oscillating circuit 23 in which the oscillating current flows through the diode bridge, formed by the 15-18, and the load 14, in the form of unipolar current pulses. When the frequency of the bridge thyristor inverter changes, the amplitude of the oscillating current flowing through the load varies within wide limits due to detonation of the resonance in the oscillator circuit 23. At resonance, the amplitude of the oscillating circuit current is Q times the amplitude of the current of the bridge thyristor inverter, where Q is the oscillatory quality factor circuit 23. The voltage on the load 14 is determined by the ratio of the capacitors 20 and 21 capacitances and the quality factor of the circuit 23 and can be more or less than the voltage across the oscillator terminals Nogo circuit. Connecting the reverse diodes J2 and 13 of the bridge thyristor inverter to the common point of the diodes 15 and 16; the shock bridge ensures the appearance of the thyristors 8 and the sufficiently high negative voltage after switching off, which speeds up the recovery of controllability of these thyristors. In addition, this ensures the flow of thyristor currents and reverse diodes of the bridge thyristor inverter through the load in one direction. Thus, the source of packets of unipolar current pulses is capable of generating packets of unipolar current pulses, continuously adjustable in amplitude. The pause between the pulse packets is formed by turning on and off the bridge thyristor inverter by the control system. Claims The source of packets of unipolar current pulses containing a series-connected direct current source, a choke and a bridge thyristor inverter with a switching LC circuit in the diagonal and reverse diodes, as well as a load included in the diagonal of the direct current of the diode bridge, characterized in that , in order to increase the amplitude of the unipolar pulses and to adjust the voltage level, two capacitors and two droplets are inserted into it, and the terminals of the diagonal of the alternating current of the diode bridge are connected two capacitors and a choke, the output of the common point of these capacitors is connected via the second choke to one thyristor group of a bridge thyristor inverter, for example an anode one, another group of thyristors of a bridge thyristor investor, for example a cathode one, is connected to the same-name group of diodes of the diode bridge, and the other group of diodes a diode bridge, for example an anodic one, is connected to the inverse inverter group of the same name. Received 58559016 thyristor bridge diodes1. USSR Author's Certificate No. 370001, Sources of Information, 2. USSR author's certificate N 300934. into account when expertise. H 02 .M 5/42, 7/72, 1971 (prototype). cl. B 23 P 1/02, 1973.