SU1505704A1 - Simulator of welding arc - Google Patents

Abstract

The invention relates to mechanical engineering, in particular to testing of power sources for arc welding, and can be used in the study of the power sources of a welding arc. The purpose of the invention is to improve the quality of testing of power sources for arc welding. The simulator of the welding arc, besides taking into account the static current-voltage characteristic, takes into account the near-electrode voltage drops, which are up to 50% of the total voltage drop on the arc. The simulator contains a functional converter and a series-connected element with controlled resistance, an element with zero differential resistance, and a current sensor. An additional functional converter connected between the current sensor and the functional converter takes into account the dynamic properties of the welding arc. 1 hp f-ly, 4 ill.

Description

The invention relates to welding production, in particular to testing power sources for arc welding, and can be used in the study and configuration of power sources of the welding arc.

The aim of the invention is to improve the quality of testing power sources for arc welding by more fully taking into account the dynamic properties of the welding arc.

FIG. 1 shows a block diagram of a welding arc simulator; in fig. 2 is a diagram of an additional functional converter; in fig. 3 - diagrams of operation of a welding arc simulator on a modulated current ;, in FIG. 4 - diagrams of the simulator operation on alternating current.

The welding arc simulator consists of a series-connected element 1, with a controlled resistance of element 2 with zero differential resistance and a current sensor 3. To exit last

An input of an additional functional converter 4 is connected, the output of which is connected to the input of a functional converter 5, which defines the statistical current-voltage characteristic of the arc column. The output of the converter 5 is connected to the controller of the first input of the element 1. The simulator is connected to the tested power source by terminals 6 and 7. The additional functional converter 4 consists of a quadrant 8, the output of which is connected through a resistor 9 to a capacitor 10 and the input of the square root extraction circuit 11 .

In the simulator of the welding arc, in addition to taking into account the statistical current-voltage characteristics, the near-electrode voltage drops are taken into account, which in welding arcs can reach 50% of the total voltage drop. The dynamic properties of the welding arc are taken into account with the help of an additional functional transformation.

about

01

catcher 5, which performs the conversion of the signal

in f + i P,

where B is a constant arc time;

i is the arc current;

ig is the current of the arc state on which the resistance of the arc column depends.

The voltage on the simulator in the dynamics is

U R (ie) i + U. -Y- E -1 + and ",

e

where UAK is a voltage drop at a two-pole, equal to the sum of the voltages of the near-electrode regions;

Due) is the function that the functional converter sets and fully coincides with the voltage on the welding arc.

The simulator works as follows. When direct current flows through the simulator on element 2, a certain voltage does not depend on the current. The signals at the output of the additional functional converter 4 are equal, therefore the functional converter 5 supplies such a voltage to element 1 that the voltage drop across it is equal to the voltage drop on the arc column in the static state. At terminals 6 and 7, the voltage is equal to the sum of the voltages of elements 1 and 2, i.e., the sum of the voltage drops on the arc column and near-electrode areas. With the modulation of the welding current, i.e., with its abrupt change, the signal at the output of the additional functional converter 4 remains unchanged at the first moment, the resistance of element 1 remains unchanged, i.e. a peak voltage arises on the arc. Subsequently, the signals at the input and output of the converter 4 are aligned, and the voltage on the simulator becomes equal to the statistical voltage on the welding arc corresponding to another welding current.

In the case of AC operation, the input and output signals of the additional functional converter 4 never coincide (Fig. 4). The characteristic ignition peaks indicate the adequacy of the work of the welding arc simulator.

Thus, the simulator has the ability to qualitatively test a large class of power sources for arc welding: DC and AC power sources, generators (including high-frequency ones), inverter power sources, switching sources, and current modulators.

15

Claims (2)

1. A welding arc imitator containing an element with a controlled resistance, the input of which is associated with a functional converter, and the output - with the sensor g g current, characterized in that, in order to increase the quality of testing of power sources for arc welding due to a more complete account of the dynamic properties of the welding arc, it is equipped with a zero differential resistance and an additional converter, the element with a zero differential resistance being connected to the output of the element, the output resistance of which is controlled by the input voltage, and the additional functional converter in; Connected between current sensor and function converter. 2. The simulator according to claim 1, characterized in that the additional functional converter consists of a quad, a square root extraction circuit, a resistor and a capacitor, wherein the quad output, via a resistor, is connected to the capacitor and the square root extraction circuit, the input of the additional functional converter, and the output of the square root extraction circuit is the output of the additional functional converter. ig.2 Lg  t