SU1624599A1 - Reactive power regulator - Google Patents

Abstract

The invention relates to electrical engineering and can be used in power installations. The purpose of the invention is to expand the functionality and by providing a compensation mode. This is achieved by sharing in it the operations of measuring reactive power with a reactive power meter 2, comparing the information signal with predetermined levels in a three-position comparison unit 10 and digital-to-analog regulation of reactive power by changing the switching phase of an energy-intensive element made in the form of an energy-intensive regulator 1 of continuous action and energy intensive regulatory authority 5 discrete action, from one discrete level to another. The change in its main parameter is much lower than its full value, which causes a decrease in the level of current harmonics in the network. 8 sludge. Yo

Description

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The invention relates to electrical engineering and can be used in power supply installations.

The purpose of the invention is to expand the functionality by providing a compensation mode.

FIG. 1 shows the electrical circuit of the regulator of reactive power; in fig. 2 is a diagram of an energy-intensive regulatory body of continuous operation; in fig. 3 is a diagram of a reactive power meter; in fig. 4 - diagrams explaining the principle of its work; in fig. 5 is a diagram of an energy-intensive regulatory authority of discrete action; in fig. 6 is a diagram of a three-position reference organ; in fig. 7 - converter code scheme - interval; in fig. 8 - diagrams explaining the principle of operation of the reactive power regulator.

The reactive power regulator contains an energy-intensive regulator 1 of continuous action connected via a meter 2 of reactive power to the terminals 3 of the network, a control unit 4, an energy-intensive regulator 5 of discrete action connected in parallel with the energy-intensive regulator 1, and a control unit based on reversible The scanner b, the low-order bits of which are connected through the converter 7 of the code into the interval to the input of the energy-intensive regulator 1 of continuous action, the older ones the output bits are connected to the input of the energy-intensive regulator 5 of the discrete action, and the input is connected to the meter control unit 8, the first input of which through the pulse shaper 9 is connected to the network terminals, and the second and third through the three-position comparison body 10 to the reactive power meter 2 , and the inputs of the reversible counter 6 are connected to the control inputs of the converter 7 code - interval.

The energy-intensive regulator 1 of continuous action is made on the basis of the grasformator-key scheme (Fig. 2). The inclusion of a thyristor in this scheme corresponds to the connection to the network capacity

C (wo + wi).

where wo and wi are the numbers of turns of the primary and secondary windings of the transformer, respectively

The reactive power meter 2 is made on the basis of the integrator, the driver and the phase shifter (Fig. 3), and the energy-intensive regulator 5 of discrete action is based on a transformer with an adjustable secondary winding (Fig. 5)

the number of turns in sections of which are referred to as integer powers of two wi - wi 2

where I 1.2p.

5The presence of a control code X on his

input corresponds to the network capacity connection

ten

(1 +) - C, WO

where X {Xi, X2Xn} w - {wi, W2,. . . wn} respectively, the control vector and the vector of turns of the secondary winding sections.

Converter code-interval 7 (Fig. 7) contains a pulse generator, a reversible counter and a comparator.

The counter control unit 8 implements a logic function.

w P s d- p g

The pulse shaper 9 is made on the basis of a cascade-connected transformer, in the primary circuit of which a resistor is connected, and a rectifier bridge.

The three-position comparison body 10 implements the function

  1 when g - h 3 | 0 when g And 1

 l at r h | U at r h

The reactive power regulator works as follows.

Reactive power meter 2

generates a potential signal r proportional to the magnitude of the reactive power in the network. This signal is compared with the power threshold values h by the three positional comparison body 10. As a result, the three-position comparison body generates logical signals S and g.

These signals through the counter control unit 8 act on the reversible counter 6. In this case, if the reactive power is negative and exceeds the modulo threshold value (half-periods 1-4), a signal S is generated that allows the passage of pulses p from the driver 9 to the subtracting input w reversible counter b, changing its state. As a consequence, there is an increase in the time interval from the beginning of the half-period corresponding to the impulse p. until the appearance of the impulse Z formed by the transducer 7, which turns on the energy-intensive regulator 1 of continuous action.

An increase in this interval leads to a decrease in the duration of the on state of the energy-intensive regulator of continuous action (diagrams of Cf versus time), and consequently, a decrease in the average level of capacitive reactive power (diagrams of Се versus time).

With a sufficiently large degree of negative power exceeding the threshold value, the duration of the on state of the energy-intensive regulator is reduced to zero (half-period 3), after which the code X changes and the energy-intensive regulator 5 of the discrete action changes to the nearest lower level (SD diagrams from time). There is no continuity of the energy-intensive regulatory authority.

If the capacitance reduction caused by such a switch is not sufficient to compensate, the duration of the on state of the energy-intensive regulator of the continuous action again decreases, rio already at a different capacitance level of the energy-intensive discrete action regulator (half-periods 4 and 5) This process continues until then. until the reactive power modulus is reduced to a threshold value.

In case of positive reactive power exceeding the threshold value in modulus, processes of the opposite nature occur, aimed at increasing the capacity of the energy-intensive regulator of discrete action and the duration of the on state of the energy-intensive regulator of continuous action, which lead to compensation with specified accuracy by the threshold values of reactive power inductive in nature (half-periods 6-10 diagrams of FIG.

P

Maximum capacity connected to the network during compensation

G, G (1 + 2P ™ - - emax M I + w Q)

determined by the maximum reactive power of the load.

In the proposed device, reactive power control is carried out by periodically changing the duration of the connected state of only a small part of the total capacity.

Sn.S (). 0 its main part

Co (2p-1)

W0 v

remains constant and not subject to periodic change. Current distortion

while insignificant.

Claims (1)

The invention includes a reactive power regulator containing a power-intensive continuous regulator, a discrete discrete regulator, a clock generator, a comparator, and a counter, connected to terminals for network connection, characterized in that, in order to extend the functionality by providing a compensation mode, It is equipped with a reactive power meter, a code-to-interval converter and a control unit counter, the comparison unit is made in three positions, and the counter is reversible, with the energy-intensive regulator of discrete action connected in parallel to the energy-intensive regulator of continuous action, to the controller to the input of which, through the code converter into the interval, the lower output bits of the counter are connected, the higher output bits of which are connected to To the control input of the energy-intensive discrete action regulator, the meter inputs are connected to the control inputs of the code converter in the interval and the meter control unit connected to the output of the pulse former, and the second and third inputs of the meter control unit are connected to the reactive power meter output through a comparison unit. Hh 3 Nl Cxi c i Oj i Figm 6o low R - & /-HER and X 21 g / 1 I L. C gfx L / ° n pki Phage 7