SU1740734A1 - Power plant shaft rotational speed regulator - Google Patents

Abstract

Usage: power engineering and autonomous power installations. In order to increase the speed of regulation, the converter 9 introduces a generator 8, a reference voltage source 10 and a threshold switch 11 to control the controller through the accumulator 5, the limiting amplifier 6 and the actuator 7 on the recycle fuel pump drive generator 2 Moreover, the control action is generated both by the deviation of the frequency of rotation of the sensor 1, kinematically connected with the shaft of the driving motor 2, and by the deviation of the voltage g 8. generators of minor modifications load control is performed linearly, with considerable load variations x - relay for the law that provides extreme fuel values in the individual phases transient yl 5.

Description

with C

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The invention relates to power plant engineering, in particular, to automatic control systems by power plants, and can be used to control the frequency of rotation of the shaft of a diesel generator.

There are known frequency stabilization systems for installations with synchronous generators, which contain centrifugal and electronic controllers with a constant driving force. These systems are made in the form of stabilization circuits for the frequency of rotation of the shaft of internal combustion engines.

The disadvantage of such devices is the low speed in transient conditions.

Closest to the invention is a system comprising a rotational speed meter, a master device, an adder, a control signal generator, a power amplifier, and an energy carrier supply actuator, which form a frequency deviation control loop, an active load sensor, and a load accelerator pulse former, which form the control loop by indignation. The control in the transitional clamp by the executive body of the supply of the energy carrier is carried out by the summary signal of the control loop for the frequency deviation and the control channel for the disturbance.

The disadvantage of the prototype is the low speed with significant load drops. This is due to the fact that the prototype implements a proportional law for the formation of a control action.

The purpose of the invention is to increase speed.

This goal is achieved in that a known device comprising a rotational speed sensor, kinematically connected to a drive motor shaft, an active load sensor, a voltage setter, an adder, an amplifier-limiter and an actuator, the output of which is connected to the rail of the fuel pump of the alternator drive engine and the output of the adder is connected to the input of the amplifier-limiter, the output of which is connected to the input of the executive body, the output of the voltage setpoint device is connected to the first non-inverting input of the totalizer Pa, the second inverting input of which is connected to the output of the frequency sensor, additionally introduced is a generator voltage converter, a reference voltage source and a threshold switch, the output of the active load sensor being connected to the first input of the threshold switch, the second input of which is connected to the output of the reference voltage source, threshold output

the switch is connected to the third non-inverting input of the adder, the fourth inverting input of which is connected to the output of a voltage converter connected to the output of the generator.

0 Fig. 1 is represented functional.

regulator circuit; Fig. 2 shows the static characteristics of the active load sensor and the rotational speed sensor; FIG. 3 shows a static characteristic of an amplifier —Ofrani5 chitel; 4 shows an embodiment of the executive body; Fig. 5 shows time diagrams of signals at the outputs of individual elements of the controller.

The rotation frequency regulator of the shaft of the energetic installation contains a rotation frequency sensor 1, kinematically connected with the shaft of the drive motor 2, the active load sensor 3, the voltage setpoint 4, the adder 5, the limiting amplifier 6 and the output unit 7, the output of which is connected to the rail of the fuel pump drive engine 2 generator 8, and the output of the adder 5 is connected to the input of the amplifier-limiter 6, the output of which

0 is connected to the input of the executive body 7. the output of the voltage setting device 4 is connected to the first non-inverting input of the adder 5. whose second inverting input is connected to the output of the frequency sensor 1. AT

5, the regulator also includes a generator 9 voltage converter, a reference voltage source 10 and a threshold switch 11, the output of the active load sensor 3 being connected to the first input

0 of the threshold switch 11, the second input of which is connected to the output of the source 10 of the reference voltage, the output of the threshold switch 11 is connected to the third non-inverting input of the adder 3, the fourth inverting input of which is connected to the output of the voltage converter 9 connected to the output of the generator 8.

Figure 2 shows the static characteristic of a resistive-load sensor as UH f (PH) (curve 1), where Un is the output signal of the sensor; PH - active power. A three-phase circuit is used as an active load sensor.

5 is made on the principle of amplitude-phase compounding taking into account the phase and amplitude of currents and voltages.

Figure 2 shows the static characteristics of the rotational speed sensor (curves 3, 2 in figure 2). Sensor combines

Two functions: the rotational speed sensor function and the setpoint adjuster function of the optimal relationship between the load and the rotational speed. The optimal dependencies of the speed and load are determined by methods known in advance, i.e. the dependence n f (PH) characterizes all speeds η for all possible loads, such that there is a minimum of fuel consumption. It is obvious that the dependence is inverse to the dependence n i (P), i.e. The ph of f (n) characterizes the values of the optimal loads for the existing (current) speeds. This dependence can be both linear and non-linear (curve 2, 3). The static characteristic of the sensor is deformed in such a way as to fully coincide with the optimal dependence P h f (n). Thus, the signal U d (Fig. 2) at the output of the rotational speed sensor 1 (Fig. 1) characterizes the magnitude of the optimal load Rn for the current value of the rotation frequency of the drive motor. In the case of a linear relationship, a tachogenerator can be used as a sensor, the slope of the static characteristic of which is chosen by including the corresponding resistance in the core circuit. In the case of a non-linear relationship, any type of standard functional transducer that implements the required non-linearity with a high approximation accuracy is included in the chain-generator.

Sensors 3 and 1 of the resistive load and rotation frequency are adjusted in such a way that the signals UH and Shmmut can be equal only at the rotation frequency that is optimal for a given load of the power plant. For any deviations of the rotational speed from the optimal value, the equality of these signals will not be fulfilled (the static control error is not taken into account).

Fig. 3 shows the static characteristic of the amplifier-limiter 6, which can be performed according to any scheme of linear amplifiers of direct current, in which the maximum narrowing of the linear section is possible by an appropriate selection of elements. The range of the linear section is chosen to be minimal according to the conditions for maintaining the stability of the power plant in transients.

As the threshold switch 11, diodes can be used that form the connection of the voltage source 10 with the output of the resistive load sensor 3, i.e. The input of summing amplifier 5 is always supplied with a higher voltage FROM DHO AND DH (FIG. 1).

Figure 4 shows an embodiment of the actuator 7. It includes a servo motor with an actuating piston 21, the rod of which is connected to the rail 20 of the fuel pump. The servo positioning is controlled by moving the spool 19, which, when moved, connects the corresponding cavities of the servomotor to the high pressure lines 17 and low pressure 18. The high pressure in the line 17 is created by the pump 16. The movements of the spool 19 are controlled by the movement of the rod, which is connected

with the crust of the electromagnet 14 and the elastic plate 15. Under the influence of the voltage UCy applied to the winding of the electromagnet 13, the measles of the electromagnet 14 moves, controlled by the position

spool and, therefore, the position of the piston 21 and the rail 20 of the fuel pump drive engine.

The regulator works as follows.

Idling on 1, 2 and 4 inputs

adder 5 receives signals 11I, respectively, from the outputs of the elements 4, 1.9. The signal from the output of the sensor 3 active load UH 0, the threshold switch

11 connects to the input 3 of the adder 5 an output of the source 10 of the reference voltage. At the output of the adder 5, a control signal is generated

UM - UH + UHO -,

whose value is such that the limiting amplifier 6 operates on the linear part of its static characteristic (Fig. 3) and a proportional control law is realized.

Under the influence of the voltage Uyo (corresponding to Ucy) applied to the winding 13 of the electromagnet (Fig. 4), due to the electromagnetic force FI, the measles 14 moves until a balance of force FI is established and

the resisting force Fa of the elastic plate 15. This changes the position of the spool 19 connecting the corresponding cavities of the servomotor to the main line 17 and 18. As a result of the movement of the piston 21

the fuel rail 20 will move and the drive engine fuel cycle will change.

The control action in the form of a voltage Ucy will be close to zero if the signals UH and ai, as well as UHO, and will be equal to within a static regulation error. Thus, the frequency of rotation of the power plant will be adjusted relative to the level

UHO voltage, i.e. will work at the minimum steady frequency.

At low loads (tenths of the nominal) voltage from the sensor 3 of the active load UH is still less than the voltage of the source 10 of the reference voltage DHO, i.e. Uh uho. Therefore, the threshold switch 11 still connects to the adder 5 the output of the voltage source 10, and the control process remains unchanged.

At time ti (figure 5) there is an increase in load. This leads to instantaneous voltage failure at the output of the generator, which is fixed by the voltage converter (signal 11). At time ti, the load current remains unchanged. Since the active load sensor assumes the multiplication of signals characterizing the current and voltage, at the time ti the voltage dip will be repeated at the output of the active load sensor 3 (signal UH). At the same time, UH will become larger than UHO. and the threshold switch 11 connects the 3rd input of the adder 5 to the output of the sensor 3 active load. A rotational frequency sensor 1 at the time will detect a frequency dip (signal), the steady-state value of the signal U will correspond to the optimal load for the steady-state frequency value (according to the static characteristic of Fig. 2). On the adder 5, the signals ui, uh, uh and uu are summed, i.e. UCy and + UH, so that at the moment ti the UCy signal transfers the limiting amplifier 6 to the relay mode, due to its static characteristic (figure 1). The step action from the output of the limiter amplifier in the form of a Uyo signal puts the actuator 7 into an extreme position. Due to the maximum cycle supply, the drive motor is formed, the voltage and current at the output of the electric generator increase almost directly proportional to the frequency of rotation. Therefore, in subsequent moments, the signal UCy begins to decrease, and when the amplifier-limiter moves from relay to proportional control law. In this case, the regulation will be made in relation to the new level, i.e. until the equality UH and the signal Uuic of the rotational speed sensor 1,

which will correspond to new revolutions, optimal for a given load value.

In the case of load discharges at which

instantaneous bursts of the output voltage occur (moment t2 of FIG. 5), control is carried out in a similar way, with a step effect on the actuator will have a reverse

sign.

Thus, during loading (s) loads almost instantaneously (at the time of the beginning of a voltage change), a stepwise (rather than monotonically varying, as in the prototype) control action is formed by the controller. This type of effect on the executive body of the fuel supply reduces the transition time of the drive engine to a new speed limit.

When load changes.

Claims (1)

The invention The regulator of the frequency of rotation of the shaft of the power plant, containing the sensor rotational speed, kinematically associated with the drive motor shaft, the active load sensor, voltage setter, adder, limiter amplifier and actuator, the output of which is connected with the rail of the fuel pump of the drive engine of the generator, the output of the adder is connected to the input of the amplifier-limiter, the output of which is connected to the input of the executive body, the output of the generator voltage is connected to the first non-inverting output of the adder, the second inverting input of which is connected to the output of a frequency sensor, characterized in that, in order to increase control speed, a generator voltage converter, a reference voltage source and a threshold switch are included in the controller, the output of the active load sensor is connected to the first input of the threshold switch, the second input of which is connected to the output of the voltage source, the output of the threshold switch is connected to the third a non-inverting input of the adder, the fourth inverting input of which is connected to the output of a voltage converter connected to the output of the generator. PHI FIG. 2 Ph Vya FIG 3 w, w Ъ VHO U Vi P B Si VCy Used -iffy 20 fae, 4  t