SU412664A1 - A DEVICE FOR THE CONTROL OF THE CONDITION OF THE VENTILATION GROUPS OF THE REVERSIBLE TRANSFORMER WITH SEPARATE CONTROL1 12 - Google Patents

Description

This invention relates to the field of conversion to converters.

iB Present time d. control of a non-reversible or reversible converter with separate control of valve groups. Several current measuring devices are used: a protection device made on AC transformers, a current sensor for a logical device of a reverse converter with separate control of valve groups; either on an AC transformer, or on a DC transformer included in the load circuit, and finally a current sensor for a system current regulator emy actuator configured to shunt the load circuit included in the amplifier.

However, during the operation of such devices, a series of power generators are duplicated, which ultimately measure the current of the converter itself and its load with varying degrees of accuracy and sensitivity. In these devices, for potential separation with a power circuit, either: magnetic amplifiers or devices with modulation-demodulation are used. The need for an implementation. The output signal of these devices from high-frequency power supply ripples increases their inertia.

The proposed device for monitoring the state of the valve groups of the reversible transformer with separate control contains three measuring transformers, the secondary windings of which are connected to a star with grounded zero and are loaded on a diode-resistive circuit through a three-phase rectifier bridge, and transistor switches and reverse conductivity controlled by a logic unit.

A special feature of the proposed device, which provides for its simplified and improved performance, is that the common point of the cathode group of the bridge is connected to the base of the transistor and the anode of the diode of the above circuit, the cathode of which is connected to two resistors, one of which is connected to earth and the other - to the collector of the reverse conduction key, and the general point is the self-identification of the grooves

the bridge through the diode is connected to the other two resistors of the indicated circuit, one of which is connected to ground, and the other to the collector of the direct conduction key, and the collectors of the keys are connected by themselves through additional resistors.

FIG. 1 shows a device diagram (serial connection of converters); Fja FIG. 2 - the same (parallel connection of converters).

3

The transformer’s power circuit includes AC transformers /, the secondary ooMOTiai of which are connected to a star and through a rectifier (a teel bridge 2 is loaded on an impedance load, made in the form of a diode-resistive circuit of diodes 3, 4 and resistors 5, 6. Zero star transformers the current is grounded. The common point of the resistors 3 and 6 is also grounded, and their other terminals are connected respectively to the resistors 7 and 8. Thus, a relatively symmetrical reversal scheme is obtained with respect to the grounded wire: diode 3 - resistor 5 and diode 4 - resistor 6. Cig al, nroiortsionalny absolute value of the current converter and removable from the resistor 5 or 6 relative to the grounding wire is proportional to the transducer current used for overcurrent protection.

If there is a current in the power circuit of the converter, a current flows through diode 3 and resistor 5. In this case, the transistor 9 is locked, and a logical signal l is supplied to the logic unit. Diode 3 increases the sensitivity of the current.

The signal taken from resistors 5 n 6 relative to the ground wire is used to control the current of the drive system. With separate control of the valve groups, and in the logic unit, signals are generated that permit the flow of the control pulses to either one or the other valve group. Thus, you determine: - the direction of the current in the load.

These signals can be used to control the transistor keys IG and //, which determine the polarity of the current signal. Thus, if the current conducts the valve group "forward", the reverse conduction switch 10 is opened, the signal taken from the resistor 5 is received by the shunt, and a signal proportional to the current of the converter with a minus sign relative to the grounded wire is fed to the drive system. If the current conducts the valve group back, the direct current JJ key is opened, the signal from resistor 6 is shunted, and the drive system receives a signal proportional to the current of the converter with a plus sign relative to the grounded wire.

four

With the sequential inclusion of two or more transducers (both with simultaneous and multi-time control) due to the fact that the current of all transducers is the same, the device can be made according to FIG. 1. At the same time, the current transformers / can be included either in the common AC circuit or in the circuit of any of the series-connected converters.

When two or more transducers are connected in parallel, each transducer must have its own device, similar to that shown in FIG. 1. A diagram of the connection of devices with each other is shown in FIG. 2. Signals from additional resistors and 13 devices are summed into a signal proportional to the current of all parallel-connected converters. The sigals taken from the collectors of the transistors of the 9 devices are assembled using diodes 14 on the "ILR1" circuit to the current presence signal.

PROPOSITION AND 3 ABOUT THIS: i

A device for monitoring the state of the valve groups of a reversible converter with separate control, containing three

instrument transformers, the secondary windings of which are connected in a star with a grounded zero and are loaded on a diode-resistor circuit through a three-phase rectifying bridge, and the transistor switches are direct

and reverse conduction controlled by a logic unit, characterized in that, in order to simplify and increase speed, the common point of the cathode group of the bridge is connected to the base of the transistor and the anode of the diode of the chain, the cathode of which is connected to two resistors, one of which is connected to ground and the other to the collector; -: the switch of the inverse conduction, and the common point of the anode group of the bridge through the diode is connected to another two resistors of the specified chain, one of which is connected to ground and the other to the collector of the switch bushes, and key collectors through Additional resistors are connected between

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