SU995256A2 - Device for asymmetric control of gate-type converter - Google Patents

Description

The invention relates to electrical engineering and is additional with respect to the main-auth.St. .W729814.

According to the main author. St. No. 7,29814, a device for asymmetrical control of a valve converter is known, which contains two threshold elements in each phase, 1 of the KOTOI JX circuits are connected {w to the corresponding inputs of the pulsed-phase control unit a distributor of pulses and two control signal sources ...

The device is also provided with two control keys with a ka phase, the input of the first one being connected to the output from the first control signal source, as well. the second input is connected to the output of the second control signal source, the outputs of both keys are connected to the inputs of the pulse-phase control unit, and the control inputs of the keys are connected to the outputs of the threshold elements.

The disadvantages of the known device is that its operation at medium control steps leads to a deterioration in the shape of the rectified current.

The purpose of the invention is the expansion of the functionality of the device.

for non-dry-running control of a valve converter.

To achieve this goal, the device is equipped in each phase with an AND-NOT element, an NOT element and an AND complementary element, and is also provided with an input command terminal, an additional IHR element with an AND-NE element, a one-shot and an additional

10 key, and in each phase the control input of the first key is connected to the output of the first threshold element through the output and the first input of the H-NOT element and the control input of the second key is connected to the input of the second threshold element through a sequence: outputs and the first input an additional element AND and the element NOT, the second inputs of the elements NAND Gu input

20 additional elements AND of all phases are combined and connected to the output of an additional NAND element, the first input of which is connected to the output up to. the element is NOT, and the second

25 input through a single-switch with an input of an additional element, NOT, the output of a single-vibration is connected to the control input of an additional key connected by its output With a common wire “30 house of the device, and the input - with the input of a second control source, the input of a single-vibration is connected to input command terminal. The drawing shows a diagram of the device. The device contains successively included threshold elements 1 and 2 and a pulsed-phase control unit 3 containing sequentially connected driver 4 sync pulses, reference voltage generator 5, zero-organ b, trigger 7, driver pulse width 8, elements 9 and 10, as well as a pulse distributor 11, a three-phase thyristor bridge 12, a control signal source 13 is adjustable, a control signal source 14 is not adjustable, keys 15 and 16, AND-NOT element 17, HE element 18, AND element 19, HE element 20 , element AND-NOT 21, key 22 and od novibrator 23. The device operates as follows. When working with a small degree of regulation by the converter, from the input command terminal to the inputs of the one-shot 23 and the HE element 20 a signal is received that provides a zero state at the output of the HE element 20 and a single state at the output of the one-vibrator 23. Output signal 1 of the AND-NE element 21 permits switching of the NAND elements 17 and 19, and thus the switching of the keys 15 and 16 alternately on signals from threshold elements 1 and 2. At the same time, the control pulse phase is determined by the “control The source voltage is 13, and on the other half-wave the source voltage is 14, thus providing asymmetrical control of the thyristors of the converter. With an increase in the degree of regulation, the signal at the terminal of the input command switches to the zero state. The O signal, appearing briefly at the output of the one-shot, closes the switch 22 which shunts the input signal of the source 13. Thus, the phase of the control pulses increases and the current of the converter stops. After a certain time, the signal 1 appears at the output of the single-foil 23, the key 22 breaks open, and at the output of the element IS-NE 21 a signal O appears, which through the elements IS-NE 17 and AND 19 signals O and 1 prevents the switching of keys 15 and 16, according to signals from threshold elements 1 and 2, and keys 15 and 16, respectively, remain in closed and open states. In this case, both the symmetric control of the thyristors of the converter is made. The controlled control voltage of the source 13 is fed to the input of the zero-organ, and the phase of the control pulses is determined by the magnitude of the control voltage of one source 13. When the control level decreases again, the signal at the input command terminal switches to the unit 19 and I-NE 21, respectively, in the zero and one states, and the one-shot remains in the initial position. The signal 1 at the input of the elements AND-NOT 17 and And 19 allows the switching of the keys 15 and 16 alternately with the signals from the threshold elements 1,2 and provides unbalanced control of the thyristors of the converter. Thus, switching from symmetric to unsymmetrical control of the thyristors of the converter occurs instantaneously as the signal at the input command terminal changes, and switching from asymmetric to symmetric control occurs with a delay of a certain time required for the current to drop to zero by reducing the input voltage of the controlled source 13 This is due to the fact that when switching from asymmetrical to symmetric control there is a sharp increase in the gain of the converter and the unregulated inrush current and alarm modes of the converter are possible. Therefore, before switching to symmetric control, it is necessary to reduce the input voltage level of the source by a certain amount, which is especially easy in closed systems, where the required input voltage level of the adjustable source 13 is automatically provided. At the same time, the key 22 shunts the input signal of the source and thereby Providing current suppression of the converter, it discharges the KS-circuit of the regulators, which can be connected to the source-13 input, and eliminates current surges when switching from unbalanced ary to symmetrical control, ensuring a zero initial condition of output regulators. The invention allows extending the functionality of a device to provide combined control with automatic change of control methods. The proposed device can be used both for a symmetrical control method with any changes in the degree of control, for which an O signal must be sent to the input of a single vibrator, and an asymmetrical control method in the entire control range must be applied to the input of a single vibrator in this case.

invention formula

Device for asymmetric control of a valve converter according to the authors St. No. 7,29814, that is, so that, in order to expand the functionality, it is equipped in each phase with an AND-NOT element, an NOT element and an additional AND element, and also provided with an INPUT command terminal, an additional element NOT, an additional element IS-NOT, a single-vibrator and a private key, and in each phase the control input of the first key is connected to the output of the first threshold element and the first input of the element and-NOT, and the control input of the second key is connected to the output .second threshold element a series connection of the output and the first input

An additional element AND and an element NOT, the second Bxopti elements NAND and the inputs of additional elements AND of all phases are combined and connected to the output, an additional element NAND, the first input of which is connected to the gate of the additional element NOT and the second input through the one-shot with the input of an additional element NOT, the gateway OD of the new vibrator is connected to the control input of the additional key connected by its output to the common wire of the device, and the input to the input of the second signal source, the one-vibrator input is connected to the input terminal to omandy.

Sources of information taken into account in the examination

1. USSR author's certificate 729814, cl. And 02 R 13/16, 1977 (prototype).

Claims (1)

Claim A device for asymmetric control of a valve converter according to ed. St. »729814, with the fact that, in order to expand the functionality, it is equipped in each phase with an AND element, an HE element and an additional AND element, and is also equipped with an input command terminal, an additional element NOT, an additional element AND -NOTE, with a single-vibrator and) an additional key, and in each phase the control input of the first key is connected to the output of the first threshold element through the output and the first input of the element and NOT, and the control input of the second key is connected to the output of the second threshold element through the last The output and the first input 20 of the additional AND element and the HB element, the second inputs of the AND elements and the inputs of the additional elements of all phases are combined and connected to the output of the additional element AND NOT, the first 5 input of which is connected to the output of the additional element NOT, and the second input is through a single-vibrator with the input of the additional element NOT, the output ОД 'of the vibrator is connected to the controlling input of an additional key, connected by its output to the device’s common wire, and by the input to the input of the second signal source, single-stroke operation is connected to terminal 15 of the input command.