SU1029308A1 - Device for detecting asynchronous operation of generator - Google Patents

Abstract

A SYNCHRONOUS DETECTION DEVICE FOR SYNCHRONOUS GENERATOR containing current and voltage transducers, two differentiating circuits and a comparator unit associated with the actuator, characterized in that, in order to increase sensitivity, selectivity and speed, two amplifiers are used in it and voltage, trigger, saw-tooth voltage and memory generator unit and notch filter, with the outputs of current and voltage converters connected to the inputs of amplifiers-formers, output Through differentiating circuits, they are connected to a trigger, the output of which is connected to the input of the sawtooth generator and memory unit, the output of which is connected through a notch filter connected to the input of the comparison unit i, the output of which is connected to the executive body. (L GO (X) oo o 00

Description

The invention relates to electrical engineering and is intended for the automatic detection of asynchronous operation of a synchronous generator. Devices for detecting the asynchronous mode (AP) of a synchronous generator are known by indirect operating parameters, for example, excitation current, reactive power, containing slip measurement units, setting setting units for activating the asynchronous protection unit 1. The disadvantages of these devices include complexity obtaining a slip value due to the lack of reliable slip sensors. The closest to the invention in its technical essence is a device for detecting an asynchronous mode in phase between a current and a stator voltage of an electrical maschine, which consists of a voltage converter and a current converter, the outputs of which are connected to the input of the comparator unit, the output of which is connected to the input of the starting organ whose output is connected to the input of the time delay block. In this device, the signals from the outputs of the current transducers and voltages are fed to a comparison unit, where the signal carrying the information on the coincidence of the phases of the compared signals is extracted. The corner selection authority controls the operation of the start-up protector 2. The device has the following drawbacks: the device response time significantly depends on the slip, the device may not work in asynchronous mode with supercritical slip, when the coincidence time of the positive half-current and voltage the comparison circuit is insignificant, the device does not reveal the asynchronous mode on the rotation of the rotor due to the considerable constant charging time of the time block capacity; By the coincidence time of the positive half-current and voltage, it is possible to fix the magnitude of the phase shift in the range of angles O-180 ° or 180-360 ° and impossible in the range O-360 °. Thus, the known device has a number of disadvantages, which lead to a low sensitivity and selectivity of the method of detecting the asynchronous mode of the SG realized by it. The purpose of the invention is to increase the sensitivity, selectivity of the device and its speed. This goal is achieved by the fact that the device for detecting the asynchronous mode of the synchronous generator, containing current and voltage transducers, two differentiating circuits and a comparison unit connected to the executive body, has two current driver amplifiers introduced. and voltage, a trigger, a sawtooth voltage and memory generator unit and a notch filter, the outputs of current and voltage converters are connected to the inputs of driver amplifiers, the outputs of which through differentiating circuits are connected to a trigger, the output of which is connected to the input of a sawtooth voltage generator and memory, the output of which is connected to the input of the comparison unit through a notch filter, the output of which is connected to the executive unit. FIG. 1 shows a block diagram of the proposed device; in fig. 2 a and b - signals from current and voltage transducers; and FIG. 3 a and b - signals after amplifiers; in fig. 4 a and b - positive impulses after differentiating chains; in fig. 5 - pulses generated by the trigger; in fig. 6 - voltages after the saw-tooth generator and storing unit. The device contains: a current transducer 1, a voltage transducer 2 connected to a current driver 3 and a voltage driver 4, differentiating circuits 5 and 6 connected to trigger 7, the output of which includes a saw-tooth voltage generator and memory 8 connected to the input of the notch filter 9, which is connected through the unit of comparison 10 with the executive body 11. The device operates as follows. The current (Fig. 2a) and the stator voltage (Fig. 2b) are fed to the inputs of current transducers 1 and voltage 2, from the outputs of which the current and voltage values are fed to the inputs of current shaping amplifiers 3 and voltage 4, respectively, where the sinusoidal signals are converted into rectangular pulses (Fig. 3a and 3b), the formed rectangular pulses are fed to the inputs of differentiating circuits 5 and 6, from the outputs of which are positive (Figures 4a and b) dif. pulses are fed to the inputs of the trigger 7, which generates pulses (Fig. 5 g), the duration of which is equal to the time between the arrival of positive diffs. pulses from chains 5 and 6, i.e. strictly proportional to the phase shift. These pulses are fed to the input of the saw-tooth voltage generator and memory 8. During the passage of a pulse, the block 8 integrates, and if it does not, the amplitude value of the voltage is stored (Fig. 6). The output signal from the block 8 is fed through a notch filter 9 to the input comparison unit 10, and in case of exceeding a predetermined setpoint, comparison unit 10 unlocks the electronic key of the executive body 11, which outputs the output signal.

The use of the proposed generator device, which is associated with an increase in

the manifestations of the asynchronous mode increases the reliability of the power station and the energy selectivity of the asynchronous re-heading as a whole.

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Claims (1)

DEVICE FOR IDENTIFICATION OF ASYNCHRONOUS MODE SYNCHRON- NEGO GENERATOR, containing current and voltage converters, two differentiating circuits and a comparison unit associated with the executive body, characterized in that, in order to increase sensitivity, selectivity and speed, two current-voltage and voltage-generating amplifiers, a trigger, a generator block are introduced into it sawtooth voltage and memory and notch filter, and the outputs of the current and voltage converters are connected to the inputs of the amplifiers-shapers, the outputs of which are connected through the differentiating circuits to the trigger A meter whose output is connected to the input of the sawtooth voltage generator and memory unit, the output of which is connected via a notch filter and connected to the input of the comparison unit Q, the output of which is connected to the executive body. f