SU1277298A1 - Device for controlling voltage of electric power station - Google Patents

Abstract

The invention relates to the regulation of the voltage and distribution of reactive loads in power plants. The purpose of the invention is to increase reliability by eliminating the overload of generators when switching branches of a communication transformer for the case of communication between a power station and higher voltage buses. This is achieved due to the fact that in the case of the voltage regulator of transformer 2 operating in the direction of decreasing voltage on the generator voltage buses, a signal appears at its output, which is fixed for a specified time by memory 7 (B). As a result, at the output of HE 9 (10), the signal disappears and the AND 3 (4) element loses conductivity, which temporarily blocks the action of controller 1. At the same time, the output of memory block 7 (8) is fed to the input of the logic element OR 18 (19), acting in the direction opposite to the subsequent action of the automatic regulator - excitation, which accompanies the switching of the regulator under the load of the communication transformer. After the time delay of the elements 20, 21 of the transformer branch switches off, and after the storage time of blocks 7 and 8 has expired, the signal at the output of the voltage regulator disappears and the control system of the power station mode acts as usual, 2 sludge. with S (L tc yu with 00

Description

The invention relates to the regulation of the voltage and distribution of reactive loads on power plants.

The aim of the invention is to avoid overloading generators when switching branches of a communication transformer for the case of communication of a power station with higher voltage buses.

Fig. 1 is a block diagram of the proposed power plant voltage control device; in fig. 2 is a diagram of a power plant connection via communication transformers having a tap-changer. I

The device circuit includes a secondary voltage regulator 1 of the power station, a voltage transformer regulator 2, IZ 4 logic gates, AND 5, 6 three-input logic gates, memory blocks 7, 8, and HE logic gates 9-14 limiters 15, 16 upper and lower excitation limits, reactive power distribution unit 17 between generators, logic elements OR 18, 19, time delaying elements 20, 21 with a time setting, slightly shorter memorization time by blocks 7 and 8; channels, respectively, are BELOW and ABOVE 22 and 23 for switching the tap-changer tap-changer branches; channels acting in the direction LESS and MORE are 24 and 25 respectively.

The power plant interconnection circuit includes, in addition, generators excitation controllers 26 and generator voltage buses 27. When switching the transformer branch under the influence of commands from the outputs 22, 23 of the voltage regulator 2 of the transformer, the voltage on the w: ina 24 is changed to a level (for example, decreases) and the excitation regulators 26 react to this change in the direction of preserving the previous voltage ( in this case, upwards, i.e., increasing the excitation of the generators), which can lead to overloading them for a time while the astatic limiter returns their mode to the permissible region

Voltage regulator 1 is common to all power station generators. In the initial position of the signals at the output of the regulator 2, the voltage of the transformer is not, and at the outputs of the logical elements 9 and 10 they exist. This ensures the conductance of the logical elements I 3 and 4, and the secondary voltage regulator 1 acts on the PAB of all generators unhindered.

The operation of the circuit proceeds as follows.

If the voltage regulator 2 of the transformer acts in the direction of decreasing the voltage on the generator voltage buses, then a signal appears at its output, which is fixed for a specified time by memory 7 (8). As a result, at the output of the element HE 9 (10), the signal disappears and the element 3 (4) loses conductivity, which temporarily blocks the action of regulator 1. At the same time, from the output of memory block 7 (8), the signal goes to the input logic element OR 18 (19), acting in the direction opposite to the subsequent action of the APB, accompanying the switching of the tap-changer of the communication transformer. After the time elements of the transformer branches 20, 21 are exhausted, after the storage time of blocks 7 and 8 has expired, the output signal of the voltage regulator 2 of the transformer disappears, the conductivity of the logic element 3 (4) is restored and the power station mode control system operates as usual.

Due to the fact that switching of the transformer branches can occur in any generator mode, a preventive change in their excitation may result in the mode not being allowed. This is eliminated due to the action of excitation limiters 11 and 12. When the generator mode is out of tolerance, the signal appears at the lower output of the limiter and disappears at the output of the AND 15 (16) logic element. As a result, they become non-conductive and the excitation stops changing in an undesirable direction.

Thus, a preventive change in the excitation of the generators operating on the network through load-regulated communication transformers preceding the switching of the tap-changer branch prevents overloading

Claims (1)

Invention Formula A power plant voltage control device containing a secondary voltage control system on the power plant tires, consisting of a secondary voltage regulator, a unit for distributing reactive power between generators and limiters for the upper and lower excitation limits of the generators and the voltage regulator for the transformer , characterized in that, in order to avoid overloading the generators when switching branches of the communication transformer for the case of communication between the power station and high-voltage buses, but it is equipped with two memory blocks, a logic gap NOT, two three-input and two two-input AND logic elements, two OR logic elements and two time delay elements, with the outputs of the More and Less channels of the voltage transformer connected to the memory blocks These outputs, whose outputs are connected to the inputs of two logical elements NOT and to one of the inputs of logical elements OR, respectively, to the other inputs of which are connected the outputs of the upper and lower limit stops; respectively, the second outputs of which through the third and fourth logic elements are not connected to the inputs of three-input logic elements AND, to the second inputs of which through the fifth and sixth logic elements are NOT respectively connected to the distribution of reactive power between generators, to the third inputs of three-input elements And are connected to the outputs of two-input logic elements And, the inputs of which are connected to the secondary voltage regulator, the other inputs of which are connected to the outputs of the first two logical elements NOT elements connected to the inputs of the time delay elements, and the outputs of the three 30 AND input logic elements are connected to the third inputs of the OR logic elements. 1rig.2 Compiled by 0. Nakazna Editor N. Shvyschka Tehred V. Kadar Proofreader A. Maksimishinets Order 6754/52 Circulation 612 Subscription VINILI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4