SU448564A1 - AUTOMATIC VOLTAGE REGULATOR FOR SYNCHRONOUS GENERATOR - Google Patents

Description

one

The invention relates to the field of control of shipboard synchronous three-phase generators.

Automatic voltage regulators for a synchronous generator are known, comprising a bridge rectifier on thyristors and diodes for supplying the excitation winding, a control unit and voltage and current measuring elements

In order to broaden the limits of regulation and provide forcing the excitation when the load is connected, from the ends of the excitation winding the proposed regulator is connected to the thyristor group of the rectifier, and the other is connected via a diode to the neutral group of the matching transformer and through the additional thyristor to the rectifier diode group. The control electrode of the additional thyristor is connected to the output of the measuring current organ. These requirements are adequately fulfilled when using a two-stage controlled three-phase thyristor rectifier with power from the generator stator as a regulator through a matching transformer with a switching thyristor depending on the load from phase to line voltage.

The invention is illustrated in the drawing, where I is a three-phase current transformer; 2 - rectifier of current transformer; 3 channel current resistors; 4 - current channel zener diode; 5 - switching thyristor; 6 - measuring bridge;

7- measuring turnout resistor;

8- control transistor;

9- voltage setting zener diode; 10 - matching transformer; II - uncoupling power diode; 12 - blocking diode;

13 - thyristors of the regulating bridge; 14 - diodes of the regulating bridge; 15- control circuit diodes; 16- control circuit diodes; 17 — initial excitation resistors; 18,19 - resistors. control circuits; 20 - field winding. In the measuring link of the regulator, the alternating voltage is converted by a rectifying bridge 6 into a constant pulsating voltage and compared with the reference voltage of the Zener diode 9. The difference is supplied from the pulsation frequency to the input of the control transistor 8 and to the limiting resistor 7. The amplifying control link controls the excitation current, depending on the degree of resistance of the generator voltage from a given three-phase bridge, in one of whose arms thyristors 13 are connected and the diodes 14 are connected to the other. This bridge is connected to the secondary winding of a three-phase matching transformer 10 connected in a star. The switching link is designed to connect the generator excitation winding 20 of the generator, depending on its load, in the case of a phase rectified bridge voltage across the isolating diode II, in the other - to a linear voltage. The switching device consists of a current transformer I, its rectifier 2, the Zener diode 4 of the switching thyristor 5 and the current channel 3 resistors. Parallel to the excitation winding 20 a blocking diode 12 is connected, which creates a circuit for the current when the excitation circuit controls the thyristor regulating circuit breaks The transistor 8, which amplifies the input signal and shunts the control transition of the thyristors 13. The tiris are closed by reverse voltage, and opened at a positive anode, the voltage across Imprinting diodes 15 and resistors 18,19. The power diodes 16 eliminate the possibility of a control signal from other phases. ; The hesistors 18 provide the initial self excitation of the generator. The regulator is based on the principle of the deviation of the controlled variable (negative feedback). Regulation is carried out in a closed loop. After self-excitation from residual magnetization, when the generator voltage is below the setpoint, i.e. a nominal voltage, the thyristor control transition 1.13 receives an input signal at a positive anode half-wave voltage, and the thyristors open, the excitation winding 20 is energized. The generator voltage increases and, when the setpoint is reached, the Zener diode 9 opens and the control transistor 8 shunts the thyristor control junctions 13. When the anode voltage passes through zero, the latter are closed and the winding turns on through a blocking diode 12. The generator collapses and the process drops. adjustment is repeated. In this case, the generator operates in the mode of self-oscillations, and the regulator performs three (different half-wave straightening by the thyristors in the first stage. As the load increases from idle to nominal, for example, a control signal is received via the current channel depending on the setting of the switching link to the switching thyristor 5, which B1 switches the linear voltage and the second diode arm, to form a semi-control bridge performing a full-wave three-phase rectification. Consequently, Switching the power of the excitation winding from the first stage to the second provides a wide change in the generator load up to significant overloads at a high power factor of the rectifier and the lowest possible voltage pulsation of the adjustable generator. BEFORE INVENTION Automatic Fade Controller