SU511665A1 - The method of separate control reversing valve converter - Google Patents

Description

one

The invention relates to methods of controlling power static converters, in particular, made on semiconductor devices with a control electrode, and 3 automated reversible industrial electric drives can be widely used.

Various methods are known for separate control of reversible valve converters, with the help of which switching of valve groups occurs as a function of the sign of the difference between the motor speed signal signals and its actual value or automatic noHCv: rp-ynnbj, in the circuit of which current conditions are measured by measuring the current s dap load, or automatic Lerzkl-after ge groups immediately after the skill of the current B to the group of conducting lonoles.

However, such methods. Management 1 is characterized by the inaccuracy of determining when the valve groups are switched. In the ideal case, the switching should take place at the moment of equal voltage between the converter and the emf. loads, as a smaller value, eg AONn, the valve group of this current direction cannot be developed.

There is also a known method of separately controlling reversible valve converters, which consists in this. that the valve grpps switch in the function of the sign of the difference between the specified voltage of the converter and the factually measured error

mean value (smooth component) of the stress on the load.

However, this method cannot provide switch-over valve groups at the moment of equal output voltage of the converter with voltage applied to the load. This prolvoolp: to the deterioration of static and m: Ed; v: ir-irtC; o ;; Characteristic converter of the invention is the provision of valve switching at the moment of equality of the output voltage of the converter with the voltage applied to the load.

Claims (1)

This is due to the fact that the sign of the difference between a given capacitance and the voltage across the load is determined at the instant that the load current is zero. In FIG. 1. timing diagrams of voltages in the output group of the valve converter and the current in the load in the discontinuous current mode; in fig. 2 is a page diagram of a logic device for implementing the proposed method. valves are turned on at time i. the phase control system at times t-locked by the action of the difference in ed. with i (thin lines on and load fig. 1). After locking the next wires at the time L on the interval (J voltage on the load is equal to its emf. If at this interval we compare the operating voltage (/ rear (dashed line in Fig. 1) with the current value of the output voltage the converter, it is possible with the necessary accuracy, limited only by the error of the comparator, Hanpt Mep zero indicator, which determines the polarity of the difference between the voltage LI and 1, to approach the ideal switching case that occurs when the output voltage is equalized bodies and voltages at the load. The corresponding inputs of the indicator indicator 1 (see Fig. 2) are supplied with the current values of the given output voltage J of the converter and the voltage at the load. From the output of the zero indicator 1, the difference sign 1 / - I) the inverse (through the element NOT 2) and the direct signal; they go to the inputs of the elements AND 3.4. The switching signals from the outputs of the elements of the elements 3.4 get to the inputs of trigger 5 only at the moment of locking the power circuit valves, i.e. when the zero signal from the output of the sensor 6 of the conductive state of the valves (indicating that the current in the load decreases to zero) is inverted by the HE element 7 and fed to the corresponding inputs of the AND 3.4 elements. Switching the trigger 5 causes a lock signal to appear. nor the working group of valves at the output of the element 8 or 9 time delay. The previously inhibited prohibition signal is removed with some delay, providing a slight pause between groups of work (on the order of 100 ISS when using modern sensors). Thus, the switching of the valve groups is carried out as a function of the sign of the difference between the instantaneous values of the given output voltage of the converter and the voltage across the load at the moment the current drops in the load to zero. Consequently, the method of separate control of a reversible valve converter ensures the switching of groups of valves when the output voltage of the converter is equal to the voltage of the load. At the same time, the adjustment characteristics of the converter (due to the precise determination of the switching point of valve groups) and the dynamic characteristics (due to an increase in the dynamic accuracy of tracking the reference signal) are significantly improved. Claims The method of separate control of a reversible valve converter by switching valve groups as a sign of the difference between a given voltage and a actually measured voltage on a load, characterized in that, in order to switch valve groups at the same time as the output voltage with voltage load, the sign of the voltage difference is determined at the moment when the load current is zero FIG. one