SU143869A1 - Device for automatic control of Cos (f) - Google Patents

Description

The subject of the invention is a device for automatically regulating cos f of industrial enterprises by acting on a group of batteries of static capacitors, allowing drying, direct determination of the change in cos cos between current and voltage. This possibility is provided by applying a circuit containing three chains, two of which contain phase shifters and forming cascades that convert a voltage proportional to the load current to square pulses of a certain duration, and a third contains a phase shifter in the form of a selsyn and forming a cascade that converts voltage network in pulses of a certain duty cycle.

The circuit includes two elements of coincidence, the signals at the output of which, via semiconductor time relays, act on the executive relays of the compensating device, respectively, in the direction of adding or reducing reactive power.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 - its basic electrical circuit.

The device (Fig. 1) has two input channels, of which

The first is supplied with a voltage Ui proportional to the current of the power supply circuit, and the second is the voltage C / 2 taken from the voltage transformer. The true angle φ (the angle between the current and voltage vector of the power circuit) corresponds to the phase shift

of the stress vectors Oi and t / 2 for the future position of the vectors tl and DZ is represented in relative form

L /, C /, and, and, -

No. 1438692

where p0 is a constant given value of the angle φ.

The voltage O through the phase rotator F and the forming cascade FC, -1 is applied as a square pulse O- to the match element I. At this, the phase shifter Φ performs a voltage shift by an angle W, and the duration of the generated pulse at the output of the forming cascade F / С- / corresponds.

Thus, the existence of an O-f pulse is determined by the range

 (that-ri). - 7 (-f o - -Il -180 °)

t- t-,

Similarly, in the second channel, an And match through the phase shifter F and the FK-2 cascade is applied to the pulse C., the existence of which is determined by the range

-Y (o-1-F1). -J (about -180 °)

o-J C In addition, the elements of coincidence MI and H2 are impulses {/ a of short duration ("starting), formed by the forming

cascade from voltage IJz- In this case, the voltage vector U is preliminarily shifted by an angle of 180 ° + pho with the aid of a selsyn-phase shifter Fz-. Thus, the regulating device is tuned to maintain a constant predetermined angle + fo. It is obvious that the pulse at the output of the coincidence element will occur if the pulse

/ Ya coincides in time with the momentum O, i.e.

where - DF1 is the angle deviation from the set in the direction of increasing its absolute value.

When this condition is fulfilled, the voltage is applied to the relay P, barking a pulse to the actuator (synchronous compensator, capacitor bank, etc.) in the direction of decreasing the angle f.

The regulating device acts in a similar way when decreasing;) the absolute value of the actual angle f), when

 B: where + AF2 is the deviation of the angle from the set in the direction of decreasing its absolute value.

Time relays PBi and PBG create a time delay between the actuation of the relay PI or PZ and the effect on actuators that change the angle f. This is necessary to prevent the actuation of actuators during short-term changes in the angle φ (for example, in transient modes).

Obviously, the installation angles H and F2 can be set to the area of the angle f, which should. support the proposed regulating device. The latter should allow you to automatically change the overall settings from any computing device. Such a change can be made by acting on the motor MF, which moves the selsyn-phase shifter Fz.

As a result, the momentum O, j. is shifted in phase by an angle ISO; {; p - - F °, where P is the rotation angle of the selsyn rotor from the MF engine. From here - the full condition of work with schema:

 I - Acpi + PI-effect on reducing the angle and

Vi

I f21 G ± - impact on the increase in angle.

To measure the angle cf, there is a symmetric trigger Tr, to which a measuring device M or a recorder C is connected according to a balanced scheme.

A trigger is supplied with "starting pulses t / -,., Generated by a cascade of FC, -4 from voltage V, and" starting pulses C ,,.

With a balanced connection of the device M to the trigger Tr, the current flowing through the device is defined by the expression 1 / ((f + P) where / (is the proportionality coefficient.

The measuring device M has two scales, one of which, fixed, serves to measure the angle F + P, and the other, mobile, is rigidly connected to the selsyn shaft.

When the shaft of the latter is rotated by angle p, the movable scale rotates by the same angle, and thus the angle φ can be measured from it and the value p can be determined.

As can be seen from the concept shown in FIG. 2, phase shifters F and F2, to which the voltage is applied from the load resistance of the current transformer, consist of resistances RI, Rz, RS and capacitance Ci and, respectively, resistances R, Rz, Rz and capacitance Cl. Variable resistances and are used to set the required values of F1 and F2. The forming cascades of FK-1 and FK-2 contain the triodes Ti, T and, respectively, Tl, T. From the outputs of the forming cascades, the pulses arrive at the coincidence elements I and // 2, consisting of Gz, 74 triodes and Gz, T, respectively. The control pulses are removed from the triode collectors. Time relays RV and RV are collected on the triodes TZ, T, T-J and, respectively, Ts, T, T-. Resistors and capacitances Ri, -C, and 4-Cl are integrating chains that are used to create a time delay. Diodes D and D limit the capacitance of the integrating circuits when the time relay trio is open.

The output polarized relay P with the neutral position of the moving contact is connected to the triodes T and Gd in a balanced circuit.

When the voltage on the integrator1, it exceeds a certain amount of relay P, it triggers and closes the iieBbm or the right contact, thereby giving a control impulse to increase or decrease cos f.

In addition, in the scheme there are two similar formative cascades of F / C-5 and, assembled on triodes Gyu, Gp, Tia, 7,3 and. respectively, Ty, Ti, Ti2.

From the Cz - D - 2 and Cz - D2 differentiating chains, the trigger impulses are sent to a trigger assembled according to a scheme with "unwrapped feedback circuits on triodes Guy, TIS, T, Tn. Pointing meter M is included in a balanced scheme between the trigger triode collectors. Potentiometer R serves to set "About the pointing device, and Potentiometer RS to adjust the required measurement limit.

The circuit is powered from the common power transformer Tr-1 through the voltage regulator CH.

The positions of the switch I on the diagram correspond to: 1 2 - setting the zone of regulation,. - measurement of the angle f.

Subject invention

Claims (3)

1. A device for automatically regulating cos f of industrial enterprises by acting on a group of batteries of static capacitors, characterized in that, in order to directly determine the change in the angle "f between current and voltage, a circuit consisting of three chains, two of which contain semiconductor phase shifters and semiconductor forming cascades that convert a voltage proportional to the load current into rectangular pulses of a certain duration, and one third contains phase orotnoe device of the synchro and a semiconductor-forming stage, which converts voltage pulses into the network a certain duty ratio, and the coincidence of two elements, the signals at the output of which through the semiconductor time switch relay actuators act on the compensating device, respectively in the direction of adding or reducing reactive power. 2. The device according to claim 1, characterized in that, in order to automatically change the setpoint of the regulator, the selsyn of the phase shifter, which converts the mains voltage, is on the same shaft as the electric motor, which can be controlled from the calculating or other the mode of operation of this group of consumers. 3. The device according to paragraphs. I and 2, characterized in that, with the purpose of measuring and registering the angle "φ and the magnitude of the angular change of the setpoint from the mode device, the controller has an additional cascade, a symmetric trigger with an expanded, reverse, and., Indicated. A sensing device with one fixed and .diah swivel scale, the porosity of which is provided by the motor of the phase shifter. .-at / l- at L. From the counting decision  - Roystba  i Editor M. P. Zolotarev Tehred A. A. Kudr vitska Proofreader N. A. Kosakovska Go to the city: ech. 20 / IV-62 g. Format boom, 70хS81 /, (; Volume 0.4-1 ed. L. Zak 1105 Circulation 1050 Price 4 kopecks TsBTI at the Committee on Inventions and Discoveries at the Council of Ministers of the USSR Moscow, Center, M. Cherkassky Lane, 2/6. Typography TsBTI Committee, Moscow, Petrovka, 14. (l) become. 11 Solts