SU78890A1 - Differentiator for synchronous-follow systems - Google Patents

Description

In order to achieve stable operation at high Q factors (the ratio of rotational speed to mismatch angle) in modern synchronous-tracking systems, a voltage proportional to the time derivative of the effective AC voltage proportional to the mismatch angle is applied to the input of the amplifier.

The need to obtain a voltage proportional to the time derivative of the effective value of the AC voltage is also encountered in other automatic devices. An example would be a device for automatically turning on an oscilloscope when recording emergency conditions in power systems. Here, the inclusion of the derivative of the effective values of voltages and currents has several advantages over other methods of starting the oscilloscope.

A disadvantage of the known differentiator for synchronous-tracking systems, consisting of an input transformer, two amplifying lamps connected in a push-pull circuit with a differentiating transformer to obtain a voltage proportional to the time derivative of the effective voltage of the monitored selsins, a filter that is connected between the lamps and A differentiating transformer is a filter with a considerable time constant. Due to the presence of the filter, the differentiator does not differentiate frequencies above 50 Hz, and the differentiation of lower frequencies is inaccurate and delayed. The advantage of the proposed differentiator is to increase the speed. Speed boosting is achieved by applying, firstly, the conversion of a differentiable single-phase voltage to a multi-phase voltage; secondly, the use of a multiphase rectifier to obtain a constant voltage, which is differentiated by a transformer. The proposed differentiator either does not contain low-frequency filters at all or has a lightweight filter.

FIG. 1 and 2 shows the electrical circuit of two variants of such a differentiator.

In the differentiator shown in FIG. 1, the single-phase voltage of the input transformer / is converted by the converter 2 into a three-phase; The latter is fed to a three-phase rectifier 3 and then the DC voltage is applied to the grids of the differentiator lamps 4 and 5. The third harmonic of the rectified voltage is reduced to a proper 1 as for HOMOHU-I capacitor 6.

The anodes of lamps 4 and 5 are powered by direct current voltage.

Automatic bias on the grid of the lamps is removed by the resistance 7, which is bridged by the capacitor 8. The output voltage is removed from the secondary winding of the differentiating transformer 5.

The use of a six-phase rectifier in the differentiator (Fig. 2) completely eliminates the need to introduce any kind of delay (4) льlt), even with a very large gain. The diagram shows the transducer 2, assembled according to the well-known scheme, allowing it to receive a resonant mode in a wide frequency range, and a six-phase rectifier 3; the remaining circuit elements are the same as in FIG. one.

The advantage of the circuit shown in FIG. 2, is the preservation of symmetry t) of the phase voltage 51 over a wider frequency range than with the circuit shown in FIG. 1. Because of this, the capacitor is absent here.

Subject invention

Differentiator for synchronous-tracking systems with a differentiating transformer to obtain a voltage proportional to the time derivative of the existing canned controlled villages, from the HI section and so that, in order to increase speed, a differentiated single-phase converter is used into a multiphase and multiphase rectifier to obtain a constant charge subjected to differentiation with the help of the transformer.

Output

9 IwJ

entrance

2 9