SU991576A1 - Method and apparatus for automatic limiting synchronous machine modes - Google Patents

Description

(54) f METHOD FOR AUTOMATIC LIMITATION OF MODES IN S1TNCHRONOUS MACHINE AND DEVICE

FOR ITS IMPLEMENTATION

-.-;}. ; :.

The invention relates to an electrical seismic, in particular, to automatic control of voltage in power systems.

When automating the control of the voltage of an electric conditioner or of the likelihood of an unacceptable increase or decrease in the excitation of synchronous machines.

; To prevent this, automatic overload control methods and automatic methods are used.

A known method of limiting the modes of a synchronous machine is that, when a deviation occurs in the parameters of the machine mode of its allowable value, the excitation of the machine changes in the direction of reducing this deviation Til and Jl2l.

At the same time, the parameters of the channel of automatic limitation of each given machine, which are determined, in particular, by a composite gain in static or

constant time in astatic devices, remain unchanged. Prv changes in modal factors, such as number and power

J ksyuchennyhmaigan. resistance sv-i z.energoobject with the power grid, etc. . -

The lack of a natural way is that the dynamic nature

The ten ticks of the process of restriction, for example, the degree of stability of this process, significantly depend on the above-mentioned regime factors and therefore, if the process parameters change when the tax rates change

15 restrictions remain unchanged,. Progress (steps in most re; w) will be suboptimal.

The closest in technical essence and reachable results

20 k zobotredennu) is a method of automatic unloading of synchronous generators and compensators, according to which when a current overload occurs, the stator or rotor is affected by the change of the excitation current proportional to the difference between the actual and rated current of the machine. The channel gain limit of the limit here remains constant regardless of the change in the mode of the power station or under the power supply, which determines the non-optimality of the limiting process when the mode differs from the calculated one. Thus, for example, with an increase in the number of generators switched on at a power plant, the process of automatic limitation decays more slowly and may even become unstable, and with a decrease in the number of generators, the static error increases, i.e. the accuracy of the automatic limit is impaired. 3J. The method is carried out by the device of automatic unloading of generators and synchronous compensators when they are overloaded, which contains an overload measuring device (automatic overload limiter), the input of which is connected to the generator current sensor, and output TO to the input of the excitation control device (automatic excitation controller) of the machine 3 However, this device, making it possible to change the excitation of the machine in the direction of reducing the napaMetpa mode deviation from the allowable one, does not make it possible to take into account the magnitude of the indicated mode factors, i.e. It does not allow for the automatic limitation according to a known method, as a result of which it does not ensure the optimality of the limitation process when the mode differs from the calculated one. The aim of the invention is to improve the quality of the automatic limiting process. This goal is achieved by the fact that, according to the method of automatically limiting the modes of a synchronous machine, the excitation of the machine in the direction of reducing the deviation of the mode parameter from the permissible one is changed, the regime factors affecting the values of the gain factors of the automatic limitation, limiting conditions, are controlled. and the indicated change in the excitation of the machine is made depending on the magnitude of these factors, and the number of switched on machines is controlled as mode factors. in, the number of lines connected to the power system or the active load of the machines. The proposed method can be implemented by a device for automatically limiting the modes of a synchronous machine, comprising an automatic mode limiter, 1/2 connected to an automatic excitation regulator, which is equipped with a tuning change element and a control unit of mode factors that influence the gain of the automatic limit, the conditions of stability and accuracy of the limitation, and the setting change element is connected to the automatic limiter of modes and to its input I give outputs connected to a control unit regime factors. In this case, the automatic limiter of modes can be implemented as an overload limiter having a measuring body in the form of a bridge of two resistors, one of which is connected to the current machine current sensor, and the other to the rated current sensor, the tuning adjustment element is executed as an amplifier with positive feedback, shunted by a resistor with tap-offs, the station mode factor determination unit is designed as a set of relay-repeaters of generators switches or lines, the control winding and the input amplifier is enabled bridge and relay contacts are connected to intermediate taps of said resistor. FIG. 1 shows a block diagram of the proposed device; FIG. 2 is a schematic diagram of one of the embodiments of the device. FIG. 1, synchronous machine 1 is equipped with an automatic excitation controller 2 and an automatic limiter of 3 modes, the input of which is connected to the sensor of the 4. control machine, and the output TCO of the input of the automatic excitation controller 2 through the channel for reducing the current deviation of the synchronous machine 1. To regulate the proposed method, the element 5 changes the settings and the unit 6 controlling the station operating factors are entered into the device. The change setting element 5 is connected to an automatic limiter of modes 3. The outputs of unit 6 are connected to the inputs of the adjustment change element 5. The inputs of block 6 are connected to the position sensors of the switchgear apparatus of the station and the sensors of the parameters of its mode. mov, for example, sensors 4 current machine and

and position sensors of switches 7 and 8 of communication lines with the power system and switches 9 of 1 O generators.

The device works as follows.

Sensors 4 and 7-10 transmit to block 6 the control of station-specific factors information about the magnitude of the current of the generators and the position of switching devices. This block, based on the specified information, finds the optimal setting of the automatic limiter of 3 modes on the basis of the previously stated rules and sets the appropriate mode limiter setting through element 5 of the adjustment change, for example, sets the appropriate value of its gain factor. The limiter of 3 modes, having drowned information from sensor 4 about the current value of the current of machine 1, determines that it is out of tolerance and, if so, sends a signal to the automatic excitation controller 2 to change the excitation of the machine in the direction of reducing the specified deviation, and the magnitude of this signal is determined Both the magnitude of the current deviation beyond the allowable limits, and the above setting of the limiter mode, which is required for optimal process. The measuring body of the automatic limiter of modes (Fig. 2) limit 3 overloads of the synchronous machine in the form of a bridge of two resistors, one of which is connected to sensor 4 of the current machine current, and the other to sensor 11 of its rated current. Element 5 is changed into the device and the unit 5 controls the operational parameters of the station. Element 5 is made in the form of an amplifier with positive feedback, shunted by a resistor 12, with a tap. The block 6 is installed in the form of a relay 13. The control input of the amplifier 5 is connected to the output of the bridge of the measuring element of the limiter 3 through the valve 14, which ensures the flow of control current only when overloaded. The contacts of the relay 13 are connected to the tapes of the resistor 12. The output of the amplifier 5 is connected to the input of the automatic excitation controller 2, and sensors are connected to the inputs of the unit 6 for determining the operating parameters of the station (the connection of switches 9 and 10 is shown (Fig. 2), i.e. changing the settings of the automatic limiter modes depending on the number of generators included).

Claims (2)

The operation of the device is that when the position of the switches 9 or 1O changes, the corresponding relay 13 is triggered, as a result of which the resulting value of the resistor 12 changes. The gain of the amplifier 5 changes accordingly. The overload limiter 3 receives information from the sensor 4 about the current value of the current 1, determines its deviation from the nominal value and, in the presence of an overload, through the amplifier 5, sends a signal to the automatic excitation controller 2 to decrease the excitation of the machine, and the magnitude of this signal, from is referred to as overload value and gain of the amplifier 5, modified in accordance with the changing ishms position switches 9 and 1O. The proposed method of the device improves the quality of the automatic limitation of the modes of synchronous machines. . Claims 1. A method of automatically limited synchronous modes of a tire installed at an electric station or substation, which consists in changing the excitation of the machine in the direction of reducing the deviation of the mode parameter from the permissible value, about the fact that improving the quality of the process of limitation, control the modal factors, which are the magnitude of the gain factors of the automatic limitation of the limiting conditions of stability and accuracy of the limitation, and the indicated change in excitation waiting machine produced t. depending on the magnitude of these factors. 2. The method according to claim 1, which means that as a mode factor, control the number of machines turned on, and with an increase in this number they decrease, and with a decrease they increase the gain factor of the automatic mode limitation. 3. The method according to claim. 1, characterized in that the magnitude of the active load of the machines is controlled, and when the active power is increased, and when reduced, the gain of the automatic limiting of the cutting modes is increased. 4. The method according to claim 1, which is controlled by the fact that (the comfort of a cop is included with the power system, and with an increase in this amount they increase, and with decreasing they decrease the gain of the automatic system). mode limitation 5. A device for automatically limiting the modes of a synchronous machine, containing an automatic mode limiter connected to an automatic excitation controller, is 6 and so that, in order to improve the quality of the limitation, it is sleep &; wife element imposing us the triplets and the control unit of modal factors, the influence of the amplification coefficient of the automatic limitation, limiting the conditions of stability and accuracy of the limitation, P1 than the element imein settings is hampered to the automatic with the limiter modes, and to the inputs fr fffff eee. - .-- f -1; r-- -. -. of the crown element, the settings are provided for the outputs of the monitoring of the mode factories, and the mode limiter is designed as an automatic overload limiter having a measuring element in the form of a bridge of two resistors, This setting was performed as a video amplifier with a positive feedback with a resistor shunted by resistor, and the unit for determining the operating factors of the power facility was executed as a set of relay repeaters of generator switches or lines, the control winding of the amplifier was connected to the output of the bridge, and the relay contacts jumped to the tapes of the mentioned resistor. Sources of information taken into account during the examination 1. V.L. Inosov and L.V. Pukernik. Compounding and electromagnetically corrected voltage of synchronous generators SEI, 1954. 2. Gendenberg G.-R. et al. A strong unified AVV scheme for hydrogenerators, turbo-generators and synchronous compensators with ion and thyristor excitation systems. MS Proceedings of VEI. Issue 81, Energie, 1972, p. 13-15. 3 USSR Author's Certificate No. 115296, cl. (1NO2P 9/10, 1956.