SU154919A1 - - Google Patents

Description

Known are voltage regulators for power transformers, made on transistors and containing two control paths, providing voltage control over two load groups, a relaxation type synchronizing generator, a logic circuit that acts independently of each time circuit, a time delay organ, and an output device , giving a signal to the circuit of the electric drive of the switch of regulated transformer. Each control path includes a voltage deviation sensor, a modulator and an amplifier.

In the proposed controller, the inputs to the voltage deviation sensors include counter-regulation elements containing current transformers and adjustable resistances. Each of these elements introduces two phase-shifted and 90 ° relative to each other voltage, proportional to the current load, which ensures the possibility of taking into account the active, and the reactance of the supply lines, or in parallel with the operation of transformers, setting negative static statistics load current and positive - 1PO reactive surge current between transformers.

A feature of the controller is also the implementation of a logic circuit consisting of two elements AND and OR, which allows the prohibition of the action of the controller to increase the voltage with the associated regulation.

In the proposed controller, the time delay organ can be performed using an integrating RC chain.

.YO 154919

FIG. Figure 1 shows a structural diagram (of the proposed voltage regulator; Fig. 2 is its printed circuit; Fig. 3 is a diagram of the counter-regulation element.

As mentioned above, the regulator contains two control paths {see FIG. 1) - the main and dololayitelny. Structurally, both these paths, up to the logical elements "AND and" OR, are identical - AND contain each element of the counter-regulation V (/), the deviation sensor - voltage 2 (2), modulators 3 to 4 (5 and 4) and amplifiers AC 5 and 6 (5 and 6) sensors. The outputs of logic elements 7 (“AND) and 8 (“ OR ”) are connected to a two-relay circuit of time-delay 9 (5), which has two output electromechanical relays 10 and // respectively, add and subtract signals.

FIG. The 1 number J2 is the clock generator and the number J3 is the power source.

The action of the regulator (after a predetermined time delay) to increase the voltage occurs only if the signals “send from voltage deviation sensors 2; and 2 both paths” appear at the input of a loop element 7 (“I”). Thereby, it is prohibited to increase the voltage of substation tires (according to the counter-regulation condition) if this is unacceptable for another group of consumers. To reduce the voltage, each path acts autonomously through the logic element 5 (“OR).

In case of emergency voltage reductions of the order of 30% of the nominal and more, the regulator fails (due to a decrease in the supply voltage), as required by the operating conditions. Therefore, a special authority to prohibit action in this case is not provided.

Since the principle of operation of both paths of the controller is identical, the operation of only one main path is considered below. The voltage t / i from the corresponding voltage transformer and the total output voltage from the counter-regulating element / proportional to the current of the corresponding line are summed up and fed to the input of the voltage deviation sensor 2.

The counter control element (see Fig. 3) contains two intermediate current transformers and two adjustable wire resistances connected in series to the cut between the secondary terminal of the input isolating transformer and the output terminal of the voltage deviation sensor 2.

When the input of the measuring body of the regulator to the voltage of the phases, for example, B and C, is turned on, one of the resistances flows around the secondary current of the two-winding intermediate current transformer included in phase L of the main current transformers.

The second resistance is likewise surrounded by a current proportional to the difference in the currents of the phases B v. C, obtained from the intermediate three-winding current transformer, the two primary windings of which are fed by the current of the phases B to C, respectively, and create a magnetizing force proportional to the difference of the currents of these phases.

Thus, the voltage drops across these resistances are out of phase with each other by 90 °.

When the load has cos, then in phase with voltage Id (Fig. 1) there is a voltage drop from the difference of currents of phases B and C (1d - / s), and the voltage drop from current of phase L (/ d) is in quadrature to Ugf. When cos is in phase, the voltage produced by the current of phase A is in phase, and the voltage from the currents of phase B is in quadrature.

As a result, it is possible to take into account the active and reactive resistances of Li-Gy in a well-known way.

The voltage deviation sensor 2 (see Fig. 2) consists of the separation T of the transformer Pr, the rectifier 1B, the UV filter and the measuring circuit.

The primary winding of the transformer Pr Pr is supplied to the input (Direct from the measuring transformer "Apr. TU. A second control element of the counter control can be included in the secondary winding circuit. Total voltage of the secondary winding of the transformer Pr and the counter control element / rectifier is measured 1B "is filtered by a filter. The rectified filtered voltage U is fed to the output of the measuring bridge, 1С Worth of srn // / - 6R n. Zener diode 1CT: and 2CT. Stabilitron 2 CJ and resistance; the 6R phenomenon accomplishes the temperature cancellation of the voltage deviation sensor.

The measuring bridge has two outputs a b b (see Fig. 1). When the voltage at the input of the bridge is equal to the set voltage of the installation, the potentials of the output clamps of the measuring organ with respect to the neutral wire of the circuit are opposite in sign but identical in absolute value. At the same time, the clamping potential b is negative, while clamping a is positive.

As the input voltage Ui increases, the potential of clamp a increases and that of clamp b decreases in absolute value. When the voltage U decreases, conversely, the potential of the clamp a decreases, and the clamp b increases in absolute value. The parameters of the measuring circuit are chosen so that when the voltage U is changed by an amount corresponding to the insensitivity zone of the regulator, the potential of the corresponding clamp changes sign.

The output voltages of sensor 2 are supplied to the inputs of the modulators 3 W. 4 controlled by the synchronization voltage Vc with a frequency of 1000 Hz, received from the r & synchronizer 12. Each of the modulators 3, 4 is a two-polar key switching signals both polarities and performed on semiconductor triodes in inverse inclusion.

The amplitude of the output voltage of the modulators 3 and 4 is proportional to the absolute value of their input voltage, and its phase relative to the synchronization voltage (O or 180 °) is determined by the polarity of the voltage. The voltage from the outputs of the modulators 3 n 4 is fed to the inputs of two-stage transistor amplifiers of alternating current 5 and 5 with parallel supply of triodes. The amplifiers operate in limiting mode, and therefore the amplitude of their output voltage does not depend on the amplitude of the input voltage.

The voltages from the outputs of the amplifiers are fed to the logical part consisting of the AND circuit (element 7) and the OR circuit (element 8). Phase-sensitive amplifiers based on IT and 2T triodes, respectively, are organically linked with these circuits. Phase-sensitive amplifiers have a transformer output through step-up transformers Tr-1 and Tr-2, and the collector circuits of the IT and 2T triodes are fed from the corresponding winding of the synchronization generator via diodes / D and 2D.

The logical elements "AND and" OR make a comparison of the phase voltages at the outputs of the amplifiers 5, 6 with the synchronization voltage and. Depending on the ratio of the phases of these voltages, the voltage arriving at the inputs of the time-delaying organ 9 (9) appears at the output of the corresponding lopic element;

No. 154919

It is sent and supplied to timing circuits. Lyolic elements MAY be made on magnetic amplifiers.

The time delay organ contains two time relays consisting of an integrating chain RC, a sensitive element (cold cathode thyratron L) and an amplifying triode ST, the collector circuit of which includes a winding of one of the output relays 10 or //. Pr, and the absence of voltage: at the input of the organ, the capacitor C is discharged, the ZG triode is locked, the winding of the executive relay is de-energized and the thyratron // is dragged. With the appearance of a voltage at the inlet of the organ, capacitor C begins to charge. When | naPrHN (Ie on the capacitor reaches a value corresponding to a given time delay, the thyratron L is ignited, which causes the ST opening triode and the output relay is processed. In the case of logic elements on magnetic amplifiers, the number of time delay units can be reduced from two (to one. With the disappearance of the signal at the organ input, the thyratron goes out, the triode is locked, the relay releases, and the capacitor C begins to discharge.

The time organ has an integrating property, since the charging and discharging of the capacitor C occurs through the same resistance R. Therefore, if a new sufficiently long-term change in the voltage of the same sign occurs after the voltage reduced or increased in voltage, then BipeM HH shutter speed is reduced.

Such a solution simplifies the design of the regulator and at the same time improves the quality of regulation.

Timing generator 12 is a conventional inductive feedback relaxation generator, the output voltage of which is rectangular. The output frequency is 1000 Hz.

Subject N obre e

Claims (3)

1. Voltage regulator for power transformers, made on transistors and containing two control paths, providing voltage control in two groups of loads and consisting of each of the voltage deviation sensor, modulator and amplifier, relaxation-type synchronization generator, logic circuit, on which each of the paths acts autonomously, the time-delaying organ and the output device, which supplies a signal to the circuit of the electric drive of the tap changer of the adjustable transformer, which distinguishes in that, to take account of the resistance and reactance line of the sensor input voltage deviation counter control element is connected, comprising current transformers and adjustable resistance. 2. The regulator according to claim 1, characterized in that, in order to enforce the prohibition of the regulator to increase the voltage with the associated regulation, the logic circuit is made of two elements AND and OR on semiconductor or magnetic amplifiers, and. - 3. The regulator according to claim 1, characterized in that the time-delaying organ is made using an RC integrating chain.