SU1700741A1 - Generator voltage regulator - Google Patents

Abstract

The invention relates to electrical engineering, in particular to electrical systems for automobiles, agricultural machines and autonomous objects containing a generator. The aim of the invention is to increase the reliability of the generator voltage regulator (PNG). The RNG contains a measuring unit 1. an output transistor switch 4, a control transistor 7. New is the introduction of the RNG protection assembly against short circuits of the excitation winding of the voltage divider generator 12, 13 and the connection of the protection transistor 9. 2 Il.

Description

1

The invention relates to electrical engineering, in particular to electrical systems for automobiles, agricultural machines and other autonomous objects containing a generator.

The aim of the invention is to increase reliability without reducing the stability of the process of turning on the power transistor switch and increasing the regulation error.

FIG. Figures 1 and 2 show circuit diagrams of a generator voltage regulator.

The generator voltage regulator (RNG) contains a measuring element 1. connected between the first 2 and second 3 terminals for connection to the power terminals of the generator. A power transistor switch 4 connected between the second 3 and the third 5 pins of the RNG. The third RNG output for connecting to the excitation winding of the generator is connected to the first output 2 via a back-switched damping diode 6. The control transistor 7 connected to the emitter-collector junction in parallel to the power transistor switch, the base to the measuring output organ 1, the emitter - to the second output 3 of the RNG, the collector through the current-limiting resistor 8 - to the first output 2 of the power supply. The protection transistor 9 is connected by the base through the first resistor 10 to the first output of the capacitor 11 connected to the second output to terminal 5 RNG, the collector to the second terminal 3 of the RNG, emitter to the midpoint of the divider 12.13 of the voltage connected to the outermost terminals between the third 5 output of the RNG and the base of the control transistor 7. The resistor voltage divider 14, 15 is connected by end terminals between the base and the emitter of the control transistor 7, the midpoint to the anode of the protection diode 16 connected by the cathode to the first capacitor terminal 11. The second cut The source 17 is connected between the second output 3 of the RNG and the first output of the capacitor 11.

The composition of the RNG (Fig. 2) includes an additional choke 18 and an additional capacitor 19, the suppressor diode 6 is connected by a cathode to the third output 5 of the RNG, and the anode to the common point of resistor 8, throttle 18, of an additional capacitor 19.

The controller works as follows.

When the voltage between the first 2 and second 3 terminals of the RNG is lower than the nominal level, the output current of the measuring body is small and insufficient to open the control transistor 7. At the same time,

The generator excitation winding circuit due to the open state of the power transistor switch 4, a current flows which, when the generator is rotating, provides an increase in the voltage on the power outputs of the generator set and, accordingly, on the first 2 and second 3 outputs of the RNG. When the adjustable voltage reaches a value slightly higher than the nominal level, the output current of the measuring body 1 increases sharply, which causes the control transistor 7 to open. The power transistor switch 4 closes and the current in the generator field winding closes through the damping diode 6, reduced by an exponential law. The voltage on the first 2 and second 3 terminals of the RNG at the same time decreases and at its value slightly below the nominal level, the output current of the measuring element decreases to a value at which the control transistor 7 closes. The power transistor switch opens and then the adjustment process proceeds as described above, as a result of which the voltage at the terminals Plus. The generator minus is automatically maintained at the nominal level.

In the anomalous short-circuit mode of the generator excitation winding, the regulator works as a relaxation generator with a high complexity of current pulses in the power transistor switch 4. The principle of the regulator in the specified anomalous mode is as follows. When the excitation winding closes, for example, at the moment; the open state of the power transistor switch 4, after the completion of the transition process in the power supply circuit (10-15 µs), goes into a linear gain mode, accompanied by an increase in voltage between the third 5 and second 3 terminals of the RNG. Due to the integrating (inertial) property of the circuit: the second resistor 17, the capacitor 11, at the considered stage of voltage increase; the protection transistor 9 remains in the closed state, and a current appears in the rigid feedback circuit (voltage divider 12, 13), which opens the control transistor 7. In the RNG circuit, a short-term regenerative process (2-3 µs) occurs, after completion of which the power transistor switch goes to the stable closed state, and the control transistor 7 goes to the open state. In the indicated state, the scheme is a sufficiently long time (2-3 µs), depending on the constant

the time of the charge circuit of the capacitor 11 and the division factor of the divider 12.13 of the voltage, by which the level of the reference voltage on the emitter of the protection transistor 9 is set. After the capacitor 11 is charged to a voltage sufficient to open the protection transistor 9, the latter opens and shunts the positive feedback signal of the transistor 7. de-energizes causing it to close. In RNG, a short-term regenerative process arises, after completion of which the power transistor switch 4 goes to the open state and the control transistor 7 goes to the closed state. At the same time, the capacitor 11 is quickly discharged along the circuit: a power transistor switch 4, a limiting resistor 15, a protection diode 16. This state of the regulator circuit is unstable, and its duration (10–15 µs) depends on the inductance of the connecting wires and the inductive component of the resistance of the battery. Upon completion of the transition process in the power supply circuit, the power transistor switch 4 goes into a linear amplification mode, accompanied by an increase in voltage between the second and third terminals of the RNG. Then the process is repeated similarly to that described, as a result of which stable self-oscillations occur in the controller. In the considered anomalous short circuit mode, the generator excitation winding in the output circuit of the power transistor switch 4 flows a pulse current, the average value of which at the resistance of the second resistor 17, which is much greater than the resistance of resistor 15, is negligible. After the removal of the specified closure, the regulator is automatically activated.

The principle of operation of the RNG (Fig. 2) is similar to the principle of the action of the RNG shown in FIG. 1. Its distinguishing feature is that the power transistor is connected according to the emitter follower circuit, the protection diode 16 is connected to the second output 3 of the PNG, the current-limiting element and the extinguishing diode 6 are connected to the first output of the power from the 2 PNG via the choke 18 , and an additional capacitor 19 is connected to the common point of the throttles 18 and the extinguishing diode 6, the other output of which is connected to the second output 3 of the NGM. The choke 18 and the capacitor 19 are designed to reduce the level of radio interference induced by the controller when switching the power transistor switch.

Due to the fact that the feedback circuit in this RNG does not have differentiating properties, the reverse voltage pulse generated between the second and third RNG terminals at the stage of opening the power transistor switch 4 has a closing effect on the control transistor 7. This eliminates the possibility of a false return of the power transistor switch 4 to the closed state and improves the control accuracy and the switching frequency of the controller.

In addition, in the proposed controller, the value of the load coefficient of the feedback circuit can be set sufficiently large without actually increasing the hysteresis and reducing the control accuracy, since the feedback function is made vanishing in functional terms. For example, when the power transistor switch 4 is closed and the discharged capacitor 11 is discharged, the protection transistor 9 is closed and the feedback ratio is maximum. As the capacitor 11 is charged, the protection transistor 9 opens and the feedback transfer ratio decreases to zero.

Thus, the use of RNG can significantly improve the reliability of the controller without reducing the stability of the process of turning on the power transistor and increasing the error of regulation.

Claims (1)

Invention Formula A generator voltage regulator containing a measuring unit connected by the input to the first and second regulator leads for communication with the power output of the generator, a power transistor, a key connected by a power transition between the second regulator lead and the third regulator lead for connecting the winding excitation of the generator connected through the extinguishing diode to the first output of the regulator, the control transistor connected to the base with the output of the measuring element, the emitter to the second output of the regulator, the collector to the base of the forces transistor switch and through the current-limiting element - with the first output of the regulator, the protection transistor connected by the base through the first resistor to the first capacitor output, the second output connected to the third output of the regulator, the first capacitor output and the second output of the regulator are connected via a diode sewn up with a direction of conductivity corresponding to the direction of conduction sequentially connected to it through a capacitor emitter-collector junction of the power a transistor switch, a second resistor, characterized in that, in order to increase reliability, a voltage divider is connected, connected by extreme leads between the third output of the regulator and the base of the control transistor, the middle output is to the emitter of the protection transistor, the collector connected to the second output of the regulator connected through a second resistor to the first capacitor terminal.