SU1275636A1 - Rectifier unit of semiconductor converter - Google Patents

Description

The invention relates to converter technology and may find application in high-power semiconductor power sources. The purpose of the invention is to enhance the functionality of the fan assembly of the semiconductor converter by allowing the state of the valves to be monitored. FIG. 1 shows a diagram of the device; in Fig. 2 and 3 are the schemes of the signal processing and indication unit. The device (Fig. 1) contains two parallel-connected valves 1 and 2, a damping circuit on a capacitor 3 and resistors 4 and 5, a resistance-leveling circuit on resistors 6 and 7, a three-winding magnetically coupled reactor 8 with windings 8.1, 8.2 and 8.3 block 9 signal processing with two inputs and one output and the node 10 of the display. The signal processing unit (Fig. 2) consists of a single-phase bridge rectifier 11, two capacitors 12 and 13, and three resistors 14-16, with a capacitor 12 connected to the first input, one output of which is simultaneously the first output terminal (q a) signal processing, the second output of this capacitor is connected to the second output terminal ((5) of the signal processing unit through the resistor 14, to the second input through a resistor 15 and a single-phase bridge rectifier 11 a capacitor 13 is connected,

one of the terminals of which is also connected to the output terminal (a), and the second through a resistor 16 to the second output terminal (S) of the signal processing unit, and the output terminal of the single-phase bridge rectifier 11 is connected to the output terminal (cx), and the display unit made on two opposite-parallel connected LEDs 17 and 18.

The signal processing unit (FIG. 3) consists of a single-phase bridge rectifier 19, two capacitors 20 and 21, three resistors 22-24 and a dynistor 25, the display unit is made on an LED 26, while parallel to the second input is connected a capacitor 20, one output of which at the same time it is the output terminal (Q) of the signal processing unit, the second output of this capacitor is connected to another output terminal (o) of the unit

which is most commonly used in semiconductor frequency converters. Application leveling by

resistance chain consisting of

two resistors 6 and 7, allows the use of one of them as a voltage presence sensor on the valves. The connection of a damping circuit parallel to the capacitor 3 along the resistance and through small and equal resistances of resistors 4 and 5 parallel to each valve balances the voltage on the power valves, moreover, as a result of this connection, there are no high-frequency harmonics on the resistance-leveling circuit turn boosts

noise immunity, signal processing unit and display unit.

Claims (4)

The device works as follows. signal processing through a resistor 22. To the first input through a resistor 23 and a single-phase bridge rectifier 19 is connected a capacitor 21, one of the terminals of which is also connected to the output terminal (Q), and the second through a resistor 24 and DIN 25 to the output terminal (8) signal processing unit, the positive output of a single-phase bridge rectifier 19 is connected to the first output (Q) and the anode of the dynistor 25 to the output output (S). The LED 26 of the indicator anode is connected to the input output (o) and the cathode to the display node (S) Damping circuit, you The capacitor 3 and the resistors 4 and 5 are designed to reduce switching overvoltages, and the connection of the capacitor 3 with one output to the common connection point is ano. The other ports are connected to the common connection point of resistors 4 and 5, the second terminals of which are connected to the cathodes of the corresponding valves, allows to damp the overvoltages on both parallel-operated valves using only one capacitor. A resistance circuit, made of resistors 6 and 7, designed to equalize the resistances of the valve nodes, is necessary when they are switched on in series. At the initial moment of time, a power voltage is applied to the fan node, and there are no control pulses, as a result, valves 1 and 2, and therefore windings 8.1 and 8.2 of reactor 8, do not flow, and there is no voltage on winding 8.3 . At the same time, the resistance leveling circuit of the resistors 6 and 7 is applied to the voltage of the power valves 1 and 2 through the damping circuit resistors 4 and 5, and the resistance value is insignificant compared to the resistors 6 and 7. In this case, part of this voltage from resistor 6 is fed to the first input of the signal processing circuit 9, and from its output the signal goes to the input of the display unit 10. The absence of voltage at the first input of the signal processing unit 9 uniquely characterizes the breakdown of one or both veins, tile 1 and 2, or the lack of time to restore the locked state when the node is operating in the AC circuit. When control valves 1 and 2 control pulses are supplied to the control electrodes, a current flows through them and, respectively, through windings 8.1 and 8.2 of reactor 8, however, due to the fact that the windings are turned on, a voltage is induced on output winding 8.3 caused by nonidentity of valve parameters. During normal operation the benthic node (a slight imbalance of valve currents), the voltage on the reactor's single winding 8 is small, which is due to the absence of a signal at the second input of the signal processing unit 9, and the device operates in an logically described, since a voltage is applied to the winding circuit in the moment of the locked state of the valves. In the event that one of the valves is not turned on for any reason or a significant flow of currents flows through the valves and 2 and the corresponding windings 8 and 8.2 of reactor 8, all or all of the current flows through one of these windings, which leads to the occurrence of voltage at the output winding 8.3 of the reactor 8, and hence at the second input of the signal processing circuit 9. This leads to a change in the signal at the output of the signal processing unit 9 and, therefore, at the input of the display unit 10. The latter allows to obtain a visual indication of the state and operability of the valve node and makes it possible to obtain the necessary information for monitoring and reliability prediction systems, for example, on a computer. With the construction of the signal processing unit 9 shown in FIG. 2, the device operates as follows. During normal operation, the second input of the signal processing unit 9 receives voltage from an impedance circuit at the moments of the locked state of the power valves, which causes the LED 17 to illuminate, indicating the normal operation of the valve node, as at the first input of the signal processing unit, connected to the winding of the reactor 8 (Fig. 1), the voltage is absent due to the equality of the currents flowing through the power valves 1 and 2 and, accordingly, the windings 8.1. and 8.2 of reactor 8 (FIG. 1). When one of the gates is not turned on at the output winding of the reactor 8 (Fig. 1), a voltage appears that is applied to the first input of the signal processing unit. The capacitor 13 is charged and its voltage is applied to the output of the signal processing unit in the polarity opposite to the polarity of the voltage coming from the second input, and the current from the reactor winding 8 should be twice the current from the equalizing circuit (LED 17 goes out) because it flows in a different direction, i.e. You-, reads. With the construction of the signal processing unit 9 shown in FIG. 3, the device operates as follows. During normal operation of the valve node of the semiconductor converter, with equal currents flowing through the power valves 1 and 2 and their correspondence to the windings 8.1 and 8.2 (Fig. 1), the voltage at the second input connected to the winding 8.3 of the reactor 8; is absent, and the LED 26 is illuminated, indicating the normal operation of the valve assembly from the voltage coming from the resistance-leveling circuit. When one of the ventilators on the winding 8.3 of the reactor 8 (Figs1) does not turn on, a voltage appears that through the resistor 23 and the single-phase bridge rectifier 19 charges the capacitor 21 (Fig 3) to the voltage of the probe of the distor 25, while the breaker pierces and the brightness of the direct voltage on the LEDs of the indication assembly LED 26 increases due to the discharge current of the capacitor 21 through the resistor 24 and the open distor 25 closes, and the process of charging the capacitor 21 with the reactor winding 8 repeats. As a result, the LED 26 knot display lane It goes into a pulsating glow mode, which indicates that the currents flowing through the power valves and reactor windings are unequal. In the case of non-locking (breakdown) of one of the valves, the second valve opens due to the reaction of the reactor 8, and there are no voltages at both inputs of the signal processing unit, which causes the display node LED 26 to go out. The latter provides a visual inspection of the non-locking (sample) of one or both valves. The formula of gain 1 is a valve node of a semiconductor converter containing two controlled semiconductor valves whose first power electrodes of the same name are interconnected, and the second are connected respectively to the different terminals of the first and second windings of a three-winding magnetically coupled reactor, the other terminals of which are interconnected, and the terminals of the third winding are connected to the first input of the signal processing unit, the output of which is connected to the display unit, which, in order to expand functional capabilities by enabling the state of the valves to be monitored, a capacitor and four resistors are inserted, the first and second resistors are connected in series between the disconnected valve power electrodes, the capacitor is connected between the connected terminals of the first and second resistors and the connected power electrodes of the third the resistor and the fourth resistor, while the signal processing unit is equipped with a second input and is made in the form of A single-phase rectifier, a first and a second capacitor, and three resistors in the signal processing unit, the input terminals of the rectifier are connected via the first resistor to its first input, the output leads are shunted by the first capacitor, and through the second resistor are connected to the output of the signal processing unit, the second input is shunted a second capacitor and a third resistor connected to the output of the signal processing unit, the second input of which is connected -. chen to the fourth resistor. 2. A valve unit according to claim 1, characterized in that a signal generator is inserted into the signal processing unit and connected in series with the second resistor. 3. A valve assembly according to claim 2, characterized in that the display unit is designed as an LED. 4. A valve assembly according to claim 1, characterized in that the display unit is made in the form of two LEDs connected in anti-parallel manner.