SU479082A1 - Turbomachine rotor speed control system - Google Patents

Description

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The invention relates to electrical systems for adjusting a process variable, preferably the rotational speed of a rotor of a turbomachine.

The known systems for controlling the frequency of rotation of the rotor of the turbomachine contain a frequency sensor connected to the rotor, a frequency adjuster, a first adder, the first input of which is connected to the setting device, and the second input is connected to the sensor, a reversing unit connected to the actuator motor bodies to the rotor of the turbomachine.

A disadvantage of the known systems is the low accuracy of operation due to the instability of the static characteristics.

The difference of the proposed system from the known ones is that it contains a second adder, the first input of which is connected to the frequency sensor, and the second one - to the setpoint device. The outputs of the first and second adders are connected to the corresponding inputs of the reversing unit.

This improves the accuracy and stability of the static characteristics of the system.

The proposed system is shown in the drawing.

The system includes a frequency sensor 1, frequency master 2, the first and second adders 3, 4, the first and second inputs 5, 6 of the reversing unit, the electric motor of the actuator installed in the supply channel of the working fluid 7, the rotor of the turbomachine 8.

Adders 3 and 4 are made in the form of subtractors with a zero output signal with a negative difference sign. So, for example, the signal at the output of the first adder 3, whose frequency is proportional to the frequency difference of the input signals, appears only when the signal frequency of the sensor 1 supplied to the first input is greater than the frequency

signal setpoint 2 supplied to the second input, i.e., when this difference is positive. If the signal at the first input is less than the second, the output signal of the adder is “zero. Similarly, the execution of the adder 4.

This makes it possible to obtain two control channels in the system: sensor 1, adder 3, input 5 of the reversing unit, which provides direct activation of the electric motor 7; setting device 2, adder 4, input 6 of the reversing unit,

providing reverse power motor 7.

The system works as follows. When the output signal f deviates, the rotation speed sensor I from the set

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the level determined by the frequency signal f zl knob 2, at the output of one of the adders 3 or 4, depending on the sign of the deviation (/ j ;, / / z), also appears the frequency signal.

The frequency of this signal is proportional to the magnitude of the deviation f - / z. As a result, the motor 7 receives pulses through the reversing unit, whose frequency is also proportional to the deviation of the actual value of the controlled parameter from the specified one. As a result, the speed of the electric motor and the system as a whole is determined by the level of the error signal - greater speed corresponds to greater speed and vice versa, which is usually a reasonable control law.

The subject of the invention is the Turbomachine rotor speed control system, which contains a frequency sensor connected to the rotor, a frequency adjuster, a first adder, the first input of which is connected to the setting device, and the second input is connected to a sensor, a reversing unit connected to the actuator electric motor installed in channel supply worker

bodies to the rotor of the turbomachine, characterized in that, in order to increase the stability of the static characteristics and the accuracy of the system, a second adder is installed in it, the first input of which is connected to the frequency sensor, and the second input is connected to the setting device, and the outputs of the first and second adders are connected with the corresponding inputs of the reversing unit.