RU2529871C1 - Arc current adaptive regulator - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: the device comprises a current sensor, a real differentiating section, a diode, a filter, a selection and storage section, a comparator, a trigger circuit, a forward-backward counter, a clock generator, a divider, a switch, summators and a current regulator.

EFFECT: reducing power current dispersion and arc extinction and in-process short-circuits.

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Description

The present invention relates to the field of electrical engineering, namely to welding equipment, in particular to control devices for welding inverters.

Welding inverters have a positive reputation among consumers. Good controllability, the ability to work in various modes, compactness, efficiency distinguish them from classical welding devices. However, in working with such electrotechnological devices, certain skills are required, the absence of which is not corrected by the quality of the equipment used. This is due to the fact that in the process of manual electric arc welding, a person is a part of the technological process - provides stability of arc burning (maintains the length of the arc gap within acceptable limits). Thus, a person is included in the control loop and his parameters affect the welding parameters: productivity, welding quality, etc. The application is devoted to the synthesis of a control system for a welding inverter with the possibility of adaptive tuning of the welding inverter for a specific person.

A technical solution is known (see patent RU No. 2311719 C1, published on November 27, 2007), in which an additional logic circuit is introduced into a typical transistor inverter control circuit consisting of two logical elements I and two voltage sensors on the inverter capacitors, the outputs of the mentioned voltage sensors and the outputs of said inverter control system are connected respectively to the inputs of the two-input logic elements AND, and the outputs of the mentioned logic elements AND are connected to the corresponding control inputs of the transistors bridge transistor inverter.

Also known is a technical solution (patent RU No. 2412031 C1, publ. 02.20.2011), in which the inverter contains two modules connected in parallel at the input, each of which is made according to the “oblique half-bridge” circuit, an RC resonant circuit is connected in parallel with the secondary winding of the transformer. The outputs of the first and second modules of the inverter are connected respectively to the first and second primary windings of the transformer, turned on counter to each other, and the output of the secondary winding of the transformer is the output of the device.

Patent search showed the lack of devices with the ability to adaptively configure the welding inverter for a specific person.

The technical result due to the application of such a setting is to reduce the dispersion of the power current and reduce the number of arc breaks and technological short circuits.

The technical result is achieved by the fact that the adaptive regulator of the welding current contains a real differentiating element, diode, filter. The peculiarity is that the filter output is connected to the input of the sampling-storage link, the comparator and the trigger circuit, the output of the sampling-storage link is connected to the input of the comparator, the outputs of which are connected to the inputs of the reversible counter, the output of the trigger circuit is connected in series to the output of the clock generator, the outputs which is connected to the sampling-storage link, a reversible counter and a pulse divider, the output of the pulse divider is connected to a switching key, which switches the signal between the adders, the outputs of which dklyucheny to the current regulator.

The invention is illustrated in the drawing, which shows a functional diagram of a welding inverter.

The proposed device contains a series-connected current sensor 1, a real differentiating element 2, a diode 3, a filter 4, the output of which is connected to the input of a sample-storage link 5, a comparator 6 and a start circuit 8. The output of the sample-storage link 5 is connected to the input of the comparator 6, the outputs of which are connected to the inputs of the reverse counter 7, the output of the trigger circuit 8 is connected in series to the input of the clock pulse generator 9, the outputs of which are connected to the sample-storage link 5, the reverse counter 7, and the divider 10 pulses. The output of the pulse divider 10 is connected to a switching key 14, which switches the signal between the adders 11 and 12, the outputs of which are connected to the current controller 13.

The device operates as follows. The power current is measured using a current sensor 1 and fed to the real differentiating element 2. The received signal is passed through a diode 3 and through a filter 4. At the output of the filter 4, the signal U _dis characterizes the dispersion level I _{d of the} power current. In the absence of I _{d, the} signal U _dis = 0 and the triggering circuit 8 keeps the adaptive controller in the state K = K ₀ , T = T ₀ , where K ₀ and T _{0 are} zero values of the transmission coefficient and the controller time constant, set in the middle of the control range, which allows you to change them in the direction of decreasing or increasing. When the current I _d appears _{, the} signal U _dis > 0, the triggering circuit 8 is triggered, which turns on the clock generator 9. Link 5 of the sample-storage provides a time delay of the signal, therefore, the variance of the current (b) and previous clock (a) is received at the input of the comparator 6. At the output of the comparator 6, two signals are formed, conditionally (+) and (-), depending on the ratio of variances on the controlled clock cycles. This allows you to control the reversible counter 7. The output of the reversible counter 7 is switched by the signal of the pulse divider 10 due to the switching key 14. Therefore, the first n clocks of the reverse counter 7 control the change (adjustment) of the coefficient K, the next n clocks control the setting of the time constant T. Adders 11 and 12 summarize the signals K and K ₀ , T and T _0, respectively, and feed them to the input of the current controller 13 within K _min <K ₀ ± n ₁ ΔK <K _max and T _min <T ₀ ± n ₂ ΔT <T _max . Then the cycle repeats.

The technical result achieved is due to the suppression of fluctuations in the power current of the arc welding due to the implementation of continuous adaptation of the circuit according to the current dispersion values and, as a result, a decrease in the number of breaks in the welding arc and technological faults, stabilization of the welding process, and improvement of the quality of the weld.

Claims (1)

An adaptive welding current regulator, characterized in that it contains a current sensor, a real differentiating element, a diode, a filter, the output of which is connected to the input of the sample-storage link, the comparator and the trigger circuit, the output of the sample-storage link is connected to the input of the comparator, the outputs of which are connected to the inputs of the reversible counter, the output of the trigger circuit is connected in series to the output of the clock pulse generator, the outputs of which are connected to the sampling-storage link, the reversible counter and the pulse divider, the output of the divider pulse is connected to the switching key, intended for switching between the signal adders, the outputs of which are connected to the current regulator.