SU1575264A1 - Method of revealing asynchronous conditions of power transmission - Google Patents

Abstract

This invention relates to the field of electrical engineering. The purpose of the invention is to increase the selectivity. For this, the asynchronous transmission mode detection measures the minimum and maximum amplitude values of the mode parameter, their ratio is calculated and, if this ratio is within the specified limits, the presence of oscillations is recorded, and the asynchronous mode is detected. have a period of not more than specified and flow for a time not less than the specified. 2 Il.

Description

The invention relates to electrical engineering, in particular, to emergency control of power systems.

The purpose of the invention is to increase the selectivity.

Figure 1 shows the functional diagram of the device that implements the method; Fig. 2 shows timing diagrams explaining his work.

The device (Fig. 1) contains the shaper 1 of the amplitude value of the input parameter, the 2-unit correction unit of the measured extreme values of the mode parameter, the organ 3 for monitoring the presence of oscillations of the mode parameter, the organ 4 for controlling the ratio of the minimum amplitude value of the mode parameter to the maximum with forward and inverse

outputs, element 5, organs 6 and 7 control the period and duration of oscillations of the regime parameter, respectively. Body 4 includes blocks 8 and 9, which measure the minimum and maximum values in each cycle, and block 10, which calculates the ratio of these values and triggers if it is within specified limits.

 driver 1 is connected by an input to the output of a mode parameter sensor and output to the combined inputs of block 2 and organs 3 and 4 connected to the information input of blocks 8 and 9, the installation inputs of which are connected in pairs to the outputs of block 2, and the outputs to the inputs of block 10, The inputs of element 5 are pairwise connected to the output of the organ 3 and the direct output of the organ

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4, and the output is connected to the working input of the body 7, the installation inputs of which are connected respectively to the inverse output of the body 4 and to the output of the body 6 connected by the input with the output of the body 3,

The operation of the circuit is explained using time diagrams (Fig. 2), where X, - are the output signals of the corresponding index blocks (X. is the signal of the inverse output of organ 4); X0 is the level at which the presence of oscillations of the mode meter ™ is monitored; T is the period of oscillation; t6 and t is the response time of organs 6 and 7.

The input of the imaging unit 1 receives a signal from the output of the sensor of the mode parameter, for example, a current transformer with a series-connected current generator to the voltage. The signal X, proportional to the amplitude value of the mode parameter, from the output of the imaging unit 1 is fed to the inputs of block 2 and organs 3 and 4, and in the latter to the inputs of blocks 8 and 9. Block 2 produces short (2-3 ms) positive pulses at the outputs a and b at the moments of changing the sign of the derivative of the input signal from positive to negative values (XgJ and back (X2g). Therefore, in each cycle of oscillations, pulses X2a set the signal X at the output of block 9, corresponding to the maximum amplitude values of the signal and pulses of X2 set

output signal of block 8 signal X

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corresponding to the minimum amplitude values of X. Block 10 is activated under the condition that the ratio of the minimum amplitude value of the mode parameter to the maximum value is within the specified limits.

Organ 3 generates short pulses X at the output for each signal X exceeded (monitored level X0, First pulse X3 sets organ 6 to zero, which, after the pulse has passed, starts counting time tg. With a period of oscillations T less than t & 6 does not have time to work during between adjacent impulse

X3 themselves, so that you

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In the course of the signal Xg is zero. In addition, in the presence of a positive X4 signal, when this ratio is within the specified limits, X pulses pass to the output of element 5 in the form of Xff pulses, the first of which triggers organ 7, since the X6 and X4 signals at its installation inputs are equal to zero . Organ 7 is triggered after time t7. When the oscillations decay, the ratio of the minimum and maximum values of the mode parameter goes beyond the specified limits, the signal X, j becomes positive and sets the organ 7 to the zero state.

The selectivity in the invented method is achieved by using the ratio of the minimum value of the mode parameter to the maximum as a determining criterion for the presence of an asynchronous mode instead of joint control of the maximum value of the mode parameter and not exceeding its minimum set value, since the specified minimum and maximum mode values parameters, such as current, vary depending on the circuit and mode of the electrical system, and their ratio is more stable Ivo, less dependent on these changes.

Claims (1)

Invention Formula The method of detecting asynchronous transmission mode, including the recording of oscillations of a regime parameter of transmission., Monitoring the period and duration of oscillations, in accordance with which the asynchronous mode of transmission is detected in the presence of oscillations of a regime parameter with a period not more than specified for a time not less than the specified one, about t This is because, in order to increase the selectivity, the minimum and maximum amplitude values of the mode parameter are additionally measured, their ratio and the presence of cola are calculated. A bani is fixed if in each of their cycles the indicated ratio is within the specified limits. Out 1 FIG. 2