SU1173503A1 - Method of controlling the fully controlled thyratron converter - Google Patents

Abstract

A METHOD OF CONTROL OF A FULLY CONTROLLED VENTILATOR CONVERTER, which consists in changing the duration of the conductive state of the valves and their switching frequency, characterized in that, in order to improve control accuracy while eliminating the intermittent current mode, the switching frequency of the valves is determined by sequential comparison of the current angle of the angle the boundary values of the unlocking angles for each switching frequency and when I reach the limit value of the current value, the frequency of the mutat is set and which corresponds to the angle of a given boundary value kommus tation, and the duration of the conductive state of the valve is varied inversely proportional to the switching frequency of the valves.

Description

11 The invention relates to electrical engineering, in particular, to control methods for valve converters providing a continuous load current mode. The purpose of the invention is to improve the accuracy of control. FIG. Figure 1 shows the diagrams of currents and voltages at the output of a fully controlled valve converter (1 - in the discontinuous current mode, 2 - in the continuous current mode in Fig 2, method 2 of eliminating the discontinuous current mode of the fully controlled valve converter on Fig. 3 - a device realizes the control method of a fully controllable transformer fan. The differential equation of the circuit for a load of the conductive state of the conductor is: di, "A l" n5 () - V –h to H :: L where WL. is inductive resistance load resistance, load angle, rad, reference angle, unlocking angle of the voltage EMF valves. The solution of this equation is: V, () (+ LP / -e HH1-e) Am Load circuit equation for each can be recorded as a falling current CJJedy The solution to this equation is: (} ((7 (For a steady state, using condition Hz 12 (2.0), you can determine de k - the number of fully activated VPs on the repetition period of the output voltage, - m . Obviously, the continuous-eye mode will take place in the case of iQ0. Thus, the condition of the intermittent-current mode winding is: g / .-, | sin e-of-VJJf (). In FIG. Figure 2 shows the dependences A / ((3) at different switching frequencies of the valves of a fully controlled VP. To ensure the continuous current mode, the range of values A located below the direct E / u should be excluded from the VP operation. For frequency frequency control is achieved by switching to a higher switching frequency of the valves at A E / U, which limits at some level the maximum value oi and ensures the conductive state of the non-return valve at the interval of the current-free memory of 7 pauses. The method described above contains a comparison unit 1, having a job input, an output connected to the input of the reversible counter 2, and a second input connected to the output of the memory unit 3. The output of the inverted counter is connected to the inputs of memory 3 and 4, the first output of the block memory 4 - with the first input of the code 5 match unit, and the second with the first input of the code 6 matching block. The second inputs of the codes 5 and 6 match blocks are connected to the outputs of the pulse counter 7, the pulse generator 8 is connected to the first input of the key 9, the second the input of which is connected to the unit ohm control 10,

3

The device works as follows

The reference signal is fed to the input of comparator 1, to the second input of which from memory 3 is supplied the current value of which i is selected from the condition of providing continuous current at the ith switching frequency of the valves of the fully controlled converter. If the unit 7g is added to the contents of i of the reversible counter 2, if a unit is added to the contents of i of the counter 2, the unit is subtracted. At oijc (A i, from the memory block 4, the values of the pause duration t and the conductive state t of the gates are extracted and fed to the inputs of the blocks 5 and 6 of the match codes.

The control unit 10 enables the operation of the block 5 of code matching, sets the pulse counter 7 to zero and opens the key 9 for passing the generator 8 pulses to the input of the counter 7. When the contents of the counter coincide with the number C, a gate f pulse is generated.

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and the control unit 10 has zeroed the counter 7 and enables the operation of the block 6 of match codes. When the contents of the counter 7 coincide with the number D 5, a pulse is blocked by the valves, and the control unit 10 zeroes the counter 7 and enables the operation of the unit 5. As a result, the units 5 and 6 work one by one at the output

0 devices are generated pulses

control V,,. , i whose frequency is determined by the reference signal and the condition for providing the continuous current mode.

The device provides a continuous load current mode in a wide range of control at the instant, the minimum switching frequency of the ventilators, and, consequently, improves the static and dynamic characteristics of the valve converter. Thus, the proposed control method makes it possible to eliminate the discontinuous current mode of the gate converter without use. physical model of the object, which increases the accuracy of control

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Claims (1)

METHOD FOR CONTROL OF A FULLY CONTROLLED VENTAL CONVERTER, consisting in changing the duration of the conductive state of the valves and their switching frequency, characterized in that, in order to improve control accuracy while eliminating intermittent currents, the switching frequency of the valves is determined by sequentially comparing the current value of the opening angle with the boundary values of the angles unlocking for each switching frequency and when the boundary value reaches the current value set the switching frequency, which This boundary value of the angle of switching corresponds, and the duration of the conducting state of the valves is changed inversely with the frequency of switching of the valves. , SU ,,., 1173503 1 1173503