SU864482A1 - Frequency regulator of power unit - Google Patents

Description

(54) ENERGO AGREGATE FREQUENCY REGULATOR

This invention relates to the frequency control of power generators operating both on an isolated load and as part of an energy system. Frequency controllers are known to turn on power amplifiers, which are associated with a switching unit of settings to ensure suppression of self-oscillations in the frequency control loop, in which the generator switch contact turns on the relay, switches the setpoint of the flexible feedback l. The closest in technical essence to the present invention is the frequency regulator of the power unit, the content meter measuring deviations of the adjustable frequency at setpoint and predator power, which are connected through the first and second inputs of the regulation law generator with the electro-hydraulic tracking system through the comparison of the current value of the signal deviation with the allowable Upper and lower limits, through the first and second one-shot, the coincidence circuit, the third one-shot. and a block for setting control settings with the third input of the driver control law. The shaper of the upper limit of tolerances is connected to the second input of the unit comparing the current value of deviations of the signal with the allowable upper limit, and the shaper of the lower limit of tolerances of deviations is connected to the second input of the unit comparing the current value of deviations of the signal to the tolerable lower limit. In accordance with the frequency reference signals received from the output of the meter of deviations of the controlled frequency from the setpoint, as well as from the output of the power setpoint generator, the regulator of the control law generates a control action of Y on the power unit. Moreover, the speed and accuracy of control actions, as well as the region of stable operation of the controller, depend on the selected value of the ycTaisoK regulator of the setpoint set by the plant settings. In the case when the dynamic properties of the object are changed so that the controller settings can no longer be provided in the new mode stability, self-oscillations begin to occur in the control loop. The most typical case of mode change is the allocation of a hydropower station to

an isolated load as a result of the disconnection of the transmission line linking the station to the power grid. A sign of the development of the auto-oscillation process can be alternating sign, deviations of the controlled variable with an amplitude exceeding the permissible limits. In order to detect automatic breakdowns, the current value of the regulating action on the power unit Y is constantly compared in blocks of comparison with permissible limits. Under the condition that the value of Y is exceeded relative to the upper limit, Uop triggers the 1st single vibrator, which forms a pulse of adjustable duration ranging from 10 to 100 s

If the deviation of the Y value is lower than the established lower permissible limit, the second one-shot operates, which also generates a pulse of adjustable duration ranging from 10 to 100 s. One-shot outputs come in a matching circuit. Thus, if a deviation with an unacceptable amplitude value of one character within 10-100 s is followed by a deviation with an unacceptable amplitude value of another sign, the coincidence circuit will work and launch the third one-shot, which generates a pulse of 1-10 minutes, which will affect the block settings, switches to settings corresponding to lower gain and more effective damping. 23 The disadvantage of this controller is the need to choose a signal to estimate the loss of stability a proaggregate, which is controlled by the controlling action Y, taken from the output of the regulator with the electro-hydraulic follow-up system. The use of a guideline sinal to assess the loss of stability is not justified by the fact that it summarizes the effects both in the frequency control channel and in the power influence channel, and its magnitude fluctuations may be caused by the requirements of the dispatcher control or output from the station control of a torus. A significant drawback of the device is also the possibility of accidental triggers when generating a signal for switching the settings of the frequency controller immediately after the first pulse is recorded. auto oscillations. The appearance of one pair of alternating measurements of the signal of the guiding apparatus can be random, the libra is a consequence of the control signals in power and do not indicate a loss of stability of the power unit and the development of an auto-oscillatory process. Premature and irregular switching of the frequency control settings has a negative effect on the quality of the control frequency and is extremely lax,

The aim of the invention is to increase the reliability and stability of a power facility in various modes of its operation and in conditions of a sudden change of these modes.

This goal is achieved by the fact that the frequency controller, which has a power delay, a meter for deviations of the adjustable frequency from the setpoint, a block for setting the controller settings, a driver for the regulation law, and the upper and lower tolerance limiters, with the corresponding schemes comparing these limits with the current value of the offsets, trigger of registration of self-oscillations, block of setting the allowable frequency of self-oscillations and block of comparing the frequency of self-oscillations, moreover, the output of the meter of deviations of the regulated h The values from the setpoint are connected via the second input of the current value comparison unit with the allowable upper deviation limit with a single installation input of the self-oscillation registration trigger, and through the second input of the comparison unit, the current value of the signal is connected with the zero installation input of the auto-oscillation registration trigger. The first input of the unit comparing the frequency of self-oscillations with a valid value is connected to the output of the self-oscillation registration trigger, the second input g from the output of the task unit of the allowable frequency of self-oscillations, and the output connected to the unit for setting the settings of the frequency regulator.

The drawing shows a block diagram of a frequency controller.

The device contains a power setting device, a meter 2 of deviations of the adjustable frequency from the setpoint, a block 3 of setting the settings of the frequency regulator shaper 4 of the control law with an electro-hydraulic tracking system, a shaper 5 of the upper limit of tolerances, a shaper of the lower limit of tolerances, block 7 comparing the current value of deviations signal with a permissible upper limit, block 8 comparing the current value of signal deviations with permissible lower limits, trigger 9 for recording self-oscillations, b Block 10 sets the permissible self-oscillation frequency; Block 11 compares the self-oscillation frequency with the permissible value.

The power setting device 1, the meter deviations adjustable frequency from

The settings 2 and the setting unit of the settings of the regulator 3 are connected to the inputs of the regulation generator with the electro-hydraulic tracking system 4. The formers of the upper 5 and lower 6 limits of the signal tolerances are connected to the first inputs of the blocks comparing the current value of the signal deviations with the valid upper 7 and with the valid, lower 8 limit. The output of the variable frequency deviation meter from setpoint 2 is connected via the second input of the unit comparing the current signal value with the allowable upper limit of deviations 7 to the unit installation input of the self-oscillation trigger 9, and through the second setting input of the unit comparing the current value of the signal to the valid lower limit 8 with zero setting the entrance trigger-registration of self-oscillations 9.

The first input of the auto-oscillation frequency comparison unit with a permissible value is connected to the output of the self-oscillation registration trigger, the second input is connected to the output of the auto-oscillation allowable frequency setting unit, and the output is connected to the frequency control setting task block. With the loss of stability of the frequency controller, for one reason or another, frequency oscillations begin to develop in the control system. A sign of the development of the auto-oscillation process is the repeated alternating frequency-frequency deviations. The output of the frequency deviation meter 2 is fed to blocks 7 and 8 comparing the current value of the signal with the permissible limits. Blocks 5 and 6 form the permissible upper and lower limits of the frequency deviation, respectively. If the deviation of the network frequency with respect to the upper limit is exceeded, the comparison circuit 7 generates a signal according to which the trigger 9 is set to one state. In the case of lowering the frequency and the transition of the amplitude of the frequency deviation below the lower limit, the comparison circuit 8 generates a signal by which the trigger 9 is set to the zero state. The switching frequency of the trigger 9 is recorded by the block 11 n in it with the permissible frequency of oscillations, the value of which is set by the block 10. If the switching frequency of the trigger 9 is exceeded relative to the acceptable value set by the block 10, the comparison circuit 11 generates a signal for switching the controller settings. The new settings of the frequency controller correspond to lower gain and slower response of the controller, thereby restoring stability in the frequency control loop.

Since the self-oscillation mode is extremely dangerous for energy, (The question of the creation of means of detecting

self-oscillations and their suppression is of great importance. In the present invention, in order to improve reliability, setpoint protection was implemented against random frequency fluctuations. The setpoint switch of the frequency regulator occurs only when the actual development of the auto-oscillatory process actually starts, which provides a more accurate match of the setpoint values to the existing mode of the power unit and, therefore, more high economic regulation indicators.

Claims (1)

Invention Formula five Frequency regulator of the power unit containing a power setting device, a meter of deviations of the adjustable frequency from the setpoint, and a block of setting the controller settings, connected to the inputs of the regulation law generator with the electro-hydraulic tracking system, the drivers of the upper and lower limits of the signal deviation, respectively, connected to the inputs of the current comparison units signal deviations with a valid upper limit and a valid lower limit, characterized in that 0 in order to increase reliability and stability, the regulator is equipped with a self-oscillation registration trigger, a block for setting an acceptable frequency of oscillations and a block comparing the frequency of self-oscillations with an acceptable 5 by a value, the meter output of the controlled frequency deviation from the setpoint is connected via the second input / comparison unit of the current signal value with a valid upper limit 0 deviation with a single installation input of the self-oscillation registration trigger, and through the second input of the current value comparison unit with a valid lower deviation with a zero installation input of the self-oscillation registration trigger, the output of which is connected to the first input of the auto-oscillation frequency comparison unit with a valid value, the second input 0, the self-oscillation comparison unit is connected to the self-oscillation allowable frequency setting unit, and the output to the frequency settings setting unit. 5 Sources of information taken into account in the examination 1.Pivovarov V.P. Design and calculation of systems for regulating hydraulic turbines, M., 1 and 1 engineering, p.215. 2c 2, Woodward project for Sait-1 HPP, hell. 9970-350, 1967. Bulletin 07058 Woodward covernor company, USA, Electric Covernor for HydraultcTurblnes