SU114528A1 - Device for automatic frequency control and active load distribution between power plants in power systems - Google Patents

Description

The task of automating the distribution of load between power plants in energy systems as they grow becomes more and more relevant.

A disadvantage of the known devices designed to solve this problem (including devices in which both automatic distribution of active load between stations and automatic frequency control are jointly carried out) is the need to measure the total load of stations from the characteristics of relative gains This is due to the possibility of the exact operation of the entire device as a whole upon leaving the system or inaccurate operation of any of the devices measuring the load of each station.

The peculiarity of the proposed device, eliminating the need to measure the total load of power plants, is the use of the integral function of frequency deviation, perceived and converted by the load distribution units according to the characteristics of relative gains, as a control pulse. The blocks are located at the control room of the power system, and each of them is connected by individual channels with a corresponding power station.

As an embodiment of such a device, it is proposed to use in load distribution units to set the characteristics of relative gains, patterns on which copiers slide that change the parameters of the master circuit of the frequency generator, which sends control signals to the regulating station.

Automatic correction of losses in the network is carried out in this device with the help of the AIR installed at the control room and provided for each of the power meters of the television meters that measure the load on the corresponding line and control the induction converter, the output voltage of which is fed into the circuit controlling the movement of the template system.

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FIG. 1-principle of an automatic active load distributor installed at the control station between stations; in fig. Figure 2 shows a flowchart of communication between a control station and two control stations.

From the dispatching point of the DP (Fig. 2), the sound frequencies / h, produced by the GZCH tube generators are transmitted to the control stations of HPP-1 and HPP-2 via communication channels KS-1 and KS-2. These frequencies are master: each value of the master frequency / 3 corresponds to the well-defined settings of the automatic power controller (the AWS of the station, and hence the well-defined load of the station. Changing the settings of the AWS as a setpoint function 1, its frequency is received by the receiving devices .

Thus, in order to change the load of any station from the control room, it is sufficient to change the master frequency transmitted to this station. The variation of the drive frequencies is made by variable capacitors Ci and Cj, included in the oscillating circuits of the respective frequency generator GZCH.

Capacitors C are designed to remotely change the loads of each station individually, for example manually - by the dispatcher.

All capacitors C are located on one common axis and are controlled by one common frequency controller for the whole system. When the frequency deviates to the system from a predetermined value, for example from 50 Hz, the AFC frequency regulator changes the capacitances of all capacitors Ci and causes a change in the loads of the stations, trying to maintain the frequency in the system at a predetermined level. Since the axes of all capacitors Ci are rigidly interconnected, with C2 const, the loads of all regulating stations are also rigidly interconnected, and therefore, when there is any number of stations in a static static frequency control, there are no special power equalizers between stations (to provide a given loads between stations) are not required.

If all the generators of any station are equipped with automatic power controllers for the workstations, when the equipment is in proper operation, the master frequency transmitted to this station is a function of the load of this station, and the axis position of the automatic frequency controller of the AFC controlling the capacitors Ci is (at Sz const) with the load function of all regulatory stations.

Such a structural scheme allows, in principle, the rejection of the telemetry of the loads at the control stations — it is enough to measure the driving frequencies and convert them into telemetry readings. At the same time, there is no need for telemetry equipment at the stations and in the corresponding telemetry channels between the stations and the control tower (instead they need channels for transmitting master frequencies from the control point to the station).

To change the load of the stations in a certain predetermined sequence, in accordance with the total characteristics of the relative increments of these stations, it is necessary to change the capacitance Ci of capacitors not linearly with the rotation of the block axis, but according to the burial defined for each capacitor. Such a capacitance mix is provided either by the special shape of the capacitor plates, reflecting the characteristic of relative gains, or by the control of the capacitors through the camshaft. In the latter case, the coupling of the axle control with the individual capacitors C occurs in a certain sequence and only at a certain angle of rotation.

A simpler way to solve the same problem is to use at the control room to measure the driving frequencies of non-co-capacitors, a of rheostats. The latter are introduced into the circuits of the frequency generator GZCH, which are executed as type C generators. By arranging the short circuits shunting the regions of the rheostats, a certain necessary sequence of change of the reference frequencies is achieved. ; Consequently, the load stations. The engines of the rheostat unit are controlled automatically by the frequency regulator or manually by the controller.

FIG. 1 is the frequency-sensitive circuit, which is controlled by the amplifier 2 by a reversible electric motor 3. The latter rotates the frame of the inductive converter (transformer sensor with variable mutual inductance) 4, not shown in the diagram, by changing the voltage at its output. The frequency-sensitive circuit, the electric motor and the induction transducer form the control unit UB. The output voltage of the control unit, 11th unit, reflects in a certain conventional scale the magnitude of the relative increase in fuel consumption or, in the case of any case, of any parameter whose function is load distribution.

The control unit UB acts on the BS station blocks, the number of which is equal to the number of teleregulirumyh stations. The impact is carried out according to the principle of a servo system (induction transducer 5, amplifier 6 and electric motor 7), so that each voltage value at the output of the control unit corresponds to a specific no. Reduction of the mechanical system of the station unit. The EtoTectroMotor 7 of the station block moves a group of templates according to the number of station units. The shape of each template S reflects the dependence of the relative increase of this unit on its load, with the load being deposited vertically, and the relative increase horizontally. By means of patterns, the capacitance of variable capacitors Ci, connected in parallel and included in the generator circuit of the frequency reference circuit (Fig. 2), is changed. The signal from this generator is transmitted to the station, and its load varies in accordance with the frequency of the signal. The total capacitance of the capacitors, and consequently, the frequency, varies depending on the position of the mobile system of the station unit in accordance with the characteristic load dependence of the stagnant on the relative increase. Since all the BS station blocks are controlled by the common control unit UB and move synchronously, the load is distributed between the stations in accordance with the characteristics of relative increments. Instead of several templates for the number of units in the station block, one template can be used that characterizes the station as a whole.

Between the control UB and the station SS blocks .ir of necessity, a unit for recording losses in the network (BUP) may be included. This unit includes a telemeter meter 9, which measures the load on the line, the loss in which changes most strongly when the load of the station changes, or on the line, the loss in which is determined by the network as a whole. In general, it can also be a load adder of several lines. An induction converter 10 is connected with the telemeter 9, the primary winding of which is supplied with the voltage OS from the output of the control unit UB, and the secondary one is connected in series to the control circuit of this station block SB. The voltage on the secondary winding of the telemeter 9 is U „UoK ,, Р„, where Р „is the power measured by the television meter, К„ is the coefficient. The voltage controlling the SS station block in this case is equal to (, „UQ

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Since UQ reflects the magnitude of the relative increase, the unit for accounting for loss of BUP provides for multiplying the relative increase by a factor (1 + АГ „Р„), in accordance with the theory of the method of relative increments.

Negative feedback on the rate of change of the total task transmitted to the stations has been introduced into the scheme. The need for feedback is due to the fact that the gain of the control system can vary widely depending on the number of units involved in the regla- relative growth, as well as on the steepness of the characteristics of the dependence of the load on the stations on the relative growth. This can seriously affect the quality of regulation, causing slow regulation in some and reregistration in other cases. Negative feedback largely eliminates this disadvantage. For its implementation, the frequencies of the signals transmitted by the station are converted by converters 11 to direct current voltages; All these voltages are switched on in series (added), and their sum is differentiated by means of a differentiating device 12. The received signal, proportional to the speed of measuring the total reference, is supplied to the amplifier 2 of the control unit. The speed of rotation of the UB control unit 3 and, consequently, the speed of movement of the patterns 8, decreases, and the rate of change of the total task at a given frequency deviation and input of the scraper unit remains approximately constant.

Subject invention

Claims (3)

1. A device for automatic frequency control and distribution of the active load between power plants in power systems, characterized in that, in order to eliminate the need for a worn out total load of the power plant, the integral function of frequency deviation, perceived and transformed by load distribution blocks according to characteristics, is used as a control pulse relative gains located at the control room of the power system and connected with individual channels, each with there is no power plant. 2. The device according to claim 1, is designed so that in order to define the characteristics of the relative gains in the load distribution units, templates are used, along which the copiers slide, which change the parameters of the master circuit of the frequency generator, which sends the control signals to the regulatory station. 3. The device according to paragraphs. 1--2, characterized in that, for the purpose of automatically introducing corrections for network losses, a telemeter meter measuring the load on the lines and controlling the induction converter, the output voltage of which is supplied to the circuit, is applied to the control station moving the template system. Osl 0 r I  I - V HCH-OO / 3 Ci t-, O Yat, Sch): ziz: