SU813662A1 - Synchronous generator voltage regulator - Google Patents

Description

one

The invention relates to electrical engineering and can be used in the automatic control systems of the output voltage of synchronous generators, widely used as autonomous power sources for electrical equipment of machine tools,

ships and others.

The devices of voltage regulators of synchronous generators are known, including those that provide frequency regulation of the generator voltage according to the T / 1-constance factor, due to the change in load l and 2.

Also known is a voltage regulator of a synchronous generator, which contains a frequency-dependent measuring element of alternating current, a rectifier and a reference element in the feedback circuit, an error signal amplifier and a power amplifier 3.

The disadvantages of this voltage regulator of the synchronous generator are low adjustment accuracy, complexity and complexity of the implementation of individual elements.

The purpose of the invention is to simplify and improve the accuracy of the frequency-dependent voltage regulation of the generator.

This goal is achieved by the fact that the voltage regulator of the synchronous generator., Which contains the frequency-dependent measuring element of alternating current, rectifier and reference element in the feedback circuit, error signal amplifier and power amplifier, is equipped with a trimming potentiometer. L-shaped smoothing

o RS filter and matching transformer, an operational amplifier with a power source on zener diodes was used as an error signal amplifier, and a serial RS-terminal was used as a frequency of a 5-dependent measuring element, connected to terminals for connection to a generator voltage, to a capacitor which

0 the primary winding of the matching transformer is connected, and these are the modes, the secondary winding of the transformer is connected to the terminals of the rectifier, to the output terminals of which is connected

5 potentiometer, trimmer, which is connected via an L-shaped smoothing EC-Filter with an inverting input of an operational error signal amplifier with polarity, providing an oppositely consistent direction

Not the output voltage of the trim potentiometer and the voltage of one IE of the two reference Zener diodes of the power supply source of the error signal amplifier, the middle point of the source being connected to the non-inverting input of the amplifier.

Figure 1 shows a schematic diagram of a voltage regulator of a synchronous generator; in fig. 2 - equivalent replacement circuit of the input frequency-dependent circuit; FIG. 3 is a static characteristic of the input-output system of automatic control (FIG. 3).

The circuit (Fig. 1) contains a driving motor 1, which rotates the synchronous generator 2 with the angular frequency oo, the output voltage of which is regulated by changing the current in the excitation winding 3. The excitation winding 3 is powered by a power amplifier 4, whose input is connected with the amplifier 5 output signal, performed on a semiconductor operational amplifier with its HC-circuit g / dynamic correction covered, adding the PID-regulator to the whole device. The power supply of the operational amplifier 5 is supplied from a DC voltage source | Through a parametric stabilizer on two series-connected Zener diodes, the ctopBX junction point, as the middle point of the yitani source, is connected to the non-inverting input of the amplifier 5.

The frequency-dependent measurement of the output voltage of the stator circuit of the Synchronous generator 2 was performed by a serial RC circuit B and 7, to the capacitor 7 of which is connected the primary winding of the transformer 8, which carries out galvanic isolation and frequency correction of the input-output regulator of the regulator. A transformer 8 is connected to the secondary winding of a single-phase valve bridge 9 loaded on the output diagonal of a direct current to a potentiometer 10 of the adjustment connected with an L-shaped smoothing RC filter 11 with an inverting input of the operational amplifier 5. At the same time due to the Counter direction of the output voltage potentiometer 10 and the voltage of one of the two reference Zener diodes power supply (Fig. 1), an element of comparison of the reference signal (Zener diode) with the signal of the feedback circuit (6-7-8-9-1011) is formed, connected to the input y the error signal silytel formed by the terminals of the inverting and non-inverting inputs of the operational amplifier 5,

FIG. Figure 2 shows the equivalent electrical circuit for replacing the input circuit of a voltage regulator of a synchronous generator.

where: Up- voltage of the synchronous generator 2, coming to the input of the circuit;

R U and - parameters of the frequency-dependent RC-circuit (6 and 7 of Fig. 1). oi is the inductance of transformer 8 according to its simplified reduced electrical circuit;

g - equivalent reduced load resistance of the secondary circuit of the transformer 8 (bridge 9, potentiometer 10, filter 11) j

Up- output voltage of the transformer 8, reduced to its primary circuit.

Fig. 3 shows the static characteristics of the input-output system of the auto-adjustment of Fig. 1, equipped with a voltage regulator of the synchronous generator 0,

where Ujv is the output voltage of the synchronous generator 2 -, (l) is the angular frequency of the speed

 generator rotor 2; UJjWiUj are the upper and lower values of the rotational speed and the frequency of the input voltage of the synchronous generator. a and 5 - static characteristics

systems with correct (a) and 0 incorrect (b) selected

Transformer parameters In the frequency correction circuit. The device works in the following way.

5 in the static steady state operation and the upper OJ value of the frequency (vradeni speed) of the synchronous generator 2, the capacitance of the capacitor 7 is small compared to the Q pre-included resistance of the resistor 6, as well as with the values given in figure 2 of the inductive resistance of the transformer 8 and res. Equivalent stress load g. Therefore, with a high degree of accuracy, the frequency dependence between the output Ui and the input Up, the voltages of the measuring circuit (Fig. 2) is inversely proportional.

9 Vyaluc

and, therefore, the necessary frequency law of regulation is ensured (direct proportionality between the output voltage and the generator and its frequency according to the characteristic a (Fig. 3).

When switching to the low-frequency (rotational speed) operation mode of the synchronous generator, i.e. S

0 and a sufficiently large inductive resistance of the transformer 8, from which the influence of which in the circuit (FIG. 2) can then be neglected, the capacitance of the capacitor 7

Claims (3)

5 increases and becomes comparable with the resistance of the equivalent load g of the measuring circuit,. there are relations .- i /. g - R-LoCjG -) At the same time, the necessary frequency law for regulating the output voltage of the synchronous generator is violated, which is shown in the graph of Fig. 3 by the deviation of the characteristic b from the characteristic a upwards, in the lower part of the frequency range of the generator. With correctly chosen parameters of the transformer 8 galvanically isolated circuits when its equivalent inductive resistance is in the low operating frequency zone of the generator, i.e. for UJ, Shu becomes comparable with the capacitance value of the capacitor 7, it is possible to carry out frequency correction of the characteristic b input-output of the device, bringing it closer to the desired characteristic a in FIG. This is due to a certain decrease in the initial capacitive conductivity of a parallel section of the measuring circuit of the circuit shown in Fig. 2 for increasing the inductive conductivity, which ultimately compensates for the shunting effect of the equivalent load g of the circuit, improving its measurement accuracy, and taking into account the correlation UK 1 () c -ji) Given this inversely proportional relationship between the output voltage Uq and the input voltage of the measuring circuit 6-7-8-9, its output voltage rectified by the bridge 9 is removed from the potentiometer 10 adjustment and enters through a smoothing RC-filter 11 to the input of the amplifier 5 error signal. Here, the voltage as a feedback signal is compared with the setting of the reference Zener diode and their difference (error signal) together with the residual pulsation voltage of the filter 11 is fed to the differential input of the operational amplifier 5, ensuring its controlled pulse-width mode work. The output of the error signal amplifier is further connected to the input of power amplifier 4 (semiconductor transistor or thyristor amplifier), which, in accordance with the amplified error signal fed to its input, provides for such current control in the generator excitation winding 3, at which the output voltage value is The rotational frequency measured by the proposed measuring circuit 6-11 corresponds to the reference, i.e. The DC output of the measuring circuit, with some deviation characteristic of the static auto-regulation system used, is compared with the reference voltage (reference zener diode). The positive effect of using the proposed regulator consists in simplifying the measuring and control circuits of the regulator and in significantly improving the accuracy of ensuring the cleanliness of controlling the output voltage of the synchronous generator with changes in ambient temperature, load and rotation speed of the drive motor. Claims A synchronous generator voltage regulator containing an alternating current frequency-dependent measuring element, a rectifier and a reference element in the feedback circuit, an error signal amplifier and a power amplifier connected to the field winding, in order to simplify and improving the accuracy of the frequency-dependent voltage regulation of the generator, it is equipped with a trimming potentiometer, an L-shaped smoothing RC filter and a matching transformer, as an error signal amplifier An operational amplifier with a power source on two zener diodes was used, and a frequency circuit was used as a frequency-dependent measuring element, the input connected to the terminals for connecting to the voltage of the generator, to the capacitor of which the primary winding of the matching transformer is connected, and the terminals of the secondary winding of the transformer are connected to the terminals of the rectifier, to the output terminals of which a potentiometer is connected, which is connected via an l-shaped smoothing 8C filter with an invert The input input of the polarity error signal amplifier provides oppositely the direction of the output voltage of the trimmer potentiometer and the voltage of one of the two reference Zener diodes of the power source of the error signal amplifier, the middle point of the power source connected to the non-inverting input of the amplifier. Sources of information taken into account during the examination 1.Winger A.A. Systems, automatic regulation of the excitation of synchronous electric machines. M., And nformstandartamelectro, 1968. 2. The US patent (2989684, class 322-23, 1961. 3. US patent 3,714,541, cl. K 02 R 9/30, 322-24, 1973.  Jb fi & 2 FIG.