JPS5890217A - Electric speed governor - Google Patents

Abstract

PURPOSE:To improve both the quick response and the stability of a speed governor, by constituting an opening controller of the speed governor, in the form of an amplifier which has the gain properties that compensates the nonlinear characteristics of an actuator. CONSTITUTION:For a hydropower plant, the speed deviation value signal f of the difference between the set output of a speed setter 10 and the signal detected the number of revolution of a water turbine generator 16 is subtracted from the output signal DELTAp of a speed drop factor operator 18. This deviation signal is fed to a PID operator 14, and the operator 14 delivers the opening command value of a proper servo motor 24. The opening command value controls a hydraulic system 26 via opening controllers 20 and 42, an actuator 22 and a motor 24. The deviation signal DELTAs between the opening value of the motor 24 which is detected by an opening detector 28 and the opening command value is fed to the controllers 20 and 42. The integrated input/output characteristics of the controllers 20 and 42 is formed in the form of an amplifier having the nonlinear gain properties that can compensate the nonlinear characteristics of the actuator 22. As a result, both the quick response and the stability can be improved for the actuator 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a proportional/integral/differential calculation type electric speed governor that adjusts the speed and output of a water turbine in a hydraulic light tJi.

BACKGROUND ART Conventionally, as this type of proportional-integral-differential calculation type electric speed governor, one having the configuration shown in FIG. 1 is known.

That is, in FIG. 1, reference numeral 10 is a speed setting device;
/2 indicates a speed detector, and /4' indicates a PID calculator. The speed detector/2 detects the rotational speed of the water turbine generator/A by converting it into an electrical signal, and reduces the difference between the output signal of the speed setting device 10 and the speed detector/2. Then, a speed deviation signal Δf is obtained. The speed deviation signal Δ obtained in this way
f is -1 for each speed; output value of rate calculator/g +4flf
Deviation from p (input fW number to PID calculator/4',
This P I]) performer/4t outputs the full servo motor opening command value for all operations 1, 11.The output signal of this I)1'D operator/4A is , open Ill: regulator ko 0, actuator 2.2
and servo motors. The hydraulic system, 2t, is controlled through 2+, and the output of the water turbine generator'gL machine/2 is appropriately controlled. In this case, the opening degree of the servo motor when adjusting the opening/closing W and f of the hydraulic system using the servo motor λ is detected by the opening detector 2g, and the opening degree obtained by the opening detector 2g is゛-Actual value of opening degree and the tool obtained from the PID calculator/g.
- Deviation from the motor opening command value Iji9
Enter J＾iJ & moderator 2°. Therefore, opening 1821
In the 14th node, 70, the opening j proportional to the deviation borrowing ΔS
#-output ΔS', actuator; 2.
2 is controlled by ftt.

The actuator 2.2 converts the opening adjustment signal .DELTA.S' into a mechanical deviation and performs all opening/closing operations of the servo motor 2. By opening and closing the servo motor 24t, the actual output frequency increases or decreases via the hydraulic system 2t and the water turbine generator/2. Further, the actual value of the servo motor opening obtained by the opening detector 2g is obtained by inputting the deviation signal from the setting signal of the load setting device 30 to the speed droop rate calculator/♂, The speed droop rate signal Δ
Find p by calculation.

However, the speed deviation signal Δf and the speed drooping rate signal ΔP are generated by a servo motor. Hydraulic system 2 for opening and closing operation of 2 hiro
The output actual frequency is adjusted to gradually decrease by increasing or decreasing via Z and the water turbine generator/J.

Therefore, the electric speed governor configured in this manner performs a control operation until the signals Δf and Δp fall within predetermined values.

In the electric speed governor, a PID calculator having a circuit configuration as shown in FIGS. 1(-) to 1(c) can be suitably used. That is, the one shown in FIG. 1 (-) is constructed so that a proportional operator 32, an integral operator 3μ, and a differential operator 36 are connected in parallel, and the outputs of each operator are combined. be. In addition, the one shown in FIG. 1 (1)) consists of a differential operator 3z, a differential operator 341, a valley line differential operator 3g, and a differential operator 36 for the input number.
The differential output and the input signal are added to the input signal, and when this is input to the integral calculator 3μ, the output of the integral calculator 3g is outputted via the restoring differential performer 3g to create a differential wave a. It is configured to calculate the deviation from the output and perform an integral calculation. Furthermore, what is shown in FIG. 2(c) K is the differential operation η
Instrument 36, Proportional/Integral Operator Gu O and Karanashi, Input Kai 11
The output obtained by differentially operating the signal by the differential calculator 3t and the input signal is added, and this is converted to a proportional 1 by the proportional/integral operator po.
It is configured to perform one integral calculation.

In the electric speed governor that performs the control operation described above, the actuator 2.2 has a nonlinear /lfH+(
Because of the characteristic line 11), the PID operator/
The output of 4/ and the opening detector of Zerbomohm H,! The integral time constant of the servo motor 2t changes according to the deviation signal ΔS from the actual value of the servo motor opening detected by g. Therefore, when the deviation signal ΔS is small (V3-O- in FIG.
Vl range), for example, when a slight frequency fluctuation occurs during no-load operation, the speed deviation signal Δf should be set to a predetermined value (PID calculation gain/Hiroshi performs control operation, but the servo motor, 2≠ integral Since the time constant is isometrically long, it becomes impossible to follow the output example of the PID calculator/4t.For this reason, when the servo motor tacho reaches its original opening, the PID calculator/g performs more integral operation than necessary. As a result, the servo motor 2 opens (or closes) further, and as a result, the frequency rises (or decreases) too much, so this should be resolved (output of PID calculator 1 ← characteristic surface 1111) and The output of the servo motor 24t (characteristic curve ■) repeats several undershoots and overshoots as shown in FIG.

Conventionally, this kind of P■D performance 3! In order to improve the output characteristics of the servo motor 24t, for example, an opening adjuster,
The gain of the servo motor 24t was increased to obtain the integral time constant e'i of the servo motor 24t in an isometric manner, thereby improving the ability to follow the output of the PID controller. However, in this case, if the gain of the opening degree 924 node and 20 is increased too much, and a negative 4X fluctuation of the rated output occurs, if the deviation signal ΔS increases slightly, the control error signal ΔS
′ is immediately shown in Figure 3. V2 or above” 2 (廿 or V4 or below)
The output will be , and the servo motor will move at a saturation speed of 1,
It is equivalent to the so-called Pangu-Bang control system in which the deviation (N ΔS is close to zero / ζ step and shifts at a very gentle aIf of 11/+. In other words, the control characteristics obtained in this way As shown in 1, "D mn device/4'
(D output (Mj+I: dir line V) For K, the output of the servo motor (lF4 characteristic curve Vl) is still at the initial saturation speed to cover the initial delay, and then gradually decreases as the deviation output ΔS becomes smaller. However, when the deviation output ΔS becomes even larger, the speed reaches saturation, and by repeating these conditions, the servo motor 2 will follow the output of the PID calculator/4t step by step.

As mentioned above, conventional electric speed governors have opening controllers,
Increasing the gain of 20 will improve stability during no-load continuous operation, but it will cause problems in the leakage control state against medium disturbances, and -
If the gain of the force opening Iff, adjuster 20 is lowered, there is no problem in the zero-pass control state, but there is a problem in that it causes incongruence in the final stability.

Therefore, the inventors of the present invention have made repeated efforts to overcome all the points between the conventional electric speed governors as described above. Tanabata Open IIL Adjustment (Cure nonlinear characteristics in the opening adjustment loop to obtain ij'-Q?l51I For the target actuator, adjust the gain of the open # regulator to fully compensate for the nonlinear characteristics of the actuator. It has been found that by providing a nonlinear characteristic, the coordination and stability of the actuator can be improved, and the above-mentioned problems can be solved.

The purpose of this is to improve quick response stability by compensating for the nonlinear characteristics of the controlled object in the opening adjustment loop configured to make the servo motor follow the calculation result of the regulator. It is an electric type W, offering a 4-speed gearbox.

In order to achieve the above objective, in the misfire 'Jl, the deviation signal between the set output of the speed setting device and the detected output of the water turbine generator is inputted, I) I D calculation is performed, and based on the obtained calculation output In an electric 14-speed machine equipped with an opening adjustment loop that follows and controls a servo motor that opens and closes the hydraulic system via an opening regulator and an actuator, the opening level 1 moderator adjusts the nonlinear characteristics of the actuator. The present invention is characterized in that it is configured as an amplifier having nonlinear gain characteristics that can be compensated.

In the electric speed governor, the open IfJw, I4 node loop includes an opening detector that detects the opening of the servo motor, and detects the opening as a deviation signal between the PID calculation output and the output of the opening detector. 1iIA! It is preferable to configure it so that it is input to a moderator.

In addition, the opening regulator is configured by connecting in parallel an opening regulator that controls linear gain characteristics and an opening regulator that handles nonlinear gain characteristics that is equipped with an output limiter circuit, and It is preferable to configure the outputs to be added.

Next, embodiments of the electric speed governor according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 6 is a circuit diagram showing an embodiment of an electric speed governor according to the present invention. For convenience of explanation, the same reference numerals are given to the same components as those of the circuit of the conventional electric speed governor shown in FIG. 1, and detailed explanation thereof will be omitted.

That is, the circuit of this embodiment is characterized in that the opening regulator 1 is connected in parallel with the conventional opening regulator IλO, and the outputs of these opening regulators T and ff are added. It is something.

The rest of the configuration is exactly the same as the circuit shown in FIG.

The input (ΔS)-output (ΔS/) characteristics of the first regulator 1.20 and the opening regulator λ configured and arranged in this way are as shown in FIG. Namely.

The opening regulator I20 is a PID calculator/4! The output characteristic (characteristic line V11) is approximately proportional to the input signal consisting of the actual value of the servo motor opening detected by the opening detector 2g and the deviation signal ΔS. Further, the opening adjuster l14t, 2 has a built-in output limiter circuit, and the deviation IIF4
Proportional output characteristics (% drawing Vll) only in the range where +3ΔS is small
l) ffij. Therefore, these opening adjusters 1,
II The output signal ΔS' obtained from VC, that is, the control signal given to the actuator 2.2, is the deviation signal ΔS
The gain is high in a range where the deviation signal ΔS is small, and the deviation signal Δ is low in a range where the difference ΔS is large.
It becomes a signal obtained by amplifying S (see characteristics &!IX in FIG. 7).

The actuator 22 and the servo motor of the circuit of this embodiment described above. If the opening adjustment loop including the second loop is simplified and displayed, it will become a circuit as shown in Fig. g (-). In this case, the actuator 22 has nonlinearity (characteristic line ■span in FIG. 3) as described above. Therefore, as mentioned above, the opening adjuster 1. Since the overall percentage characteristic of II is an amplifier with non-linear gain characteristics (characteristic line ! , actuator, the non-linearity of 2.2 is improved and compensated for to linear characteristics.

As is clear from the above, according to the present invention,
For deviation No. 18 ΔS such that the actuator 22 does not enter the saturation 11] region, the opening adjusters 1, II (-
K is the total gain of 20, 2) and actuator 2-. Then, once the overall characteristic of the control loop is a first-order lag with a time constant of %/Ko, as shown in Figure 2, the output of the PID calculator (characteristic line X) becomes the initial Even if it changes, the output of the servo motor, 2hiro (%
curve XI) can be followed smoothly.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned electric speed governor. Various types with loops that follow! It can be widely applied to control devices, and various configurations can be made in the concave circle without departing from the spirit of the present invention. ? r
:Of course there are 868 things that can be done.

[Brief explanation of the drawing]

Is Figure 1 conventional? Block circuit diagram of a-type WI series machine,
Figures 2 (+1) to (C) are shown in Figure 1 i) I I
) A block diagram showing different circuit examples of arithmetic units, Fig. 3 is a nonlinear characteristic diagram of the actuator shown in Fig. 1,
Figure i is a characteristic curve diagram of the opening adjustment loop shown in Figure 1. Figure Q", revised) characteristic curve diagram of the opening adjustment loop,
FIG. 1 is a block circuit diagram of an electric speed governor according to the present invention,
Figure 7 shows the input and output of the opening adjuster shown in Figure 2! f
(b) is a circuit diagram showing the opening shift of the circuit shown in Fig. 4. Figure 7 is a circuit diagram showing the characteristics of the four-node loop, and Fig. 7 is the opening degree of the circuit shown in Fig. 6. -! It is a characteristic curve diagram of the 1-node loop. 10...Speed setter 7.2...Speed detector/
≠...PID calculator /l...Hydrogen generator/r
...Velocity droop rate factor λθ...υ1j degrees θ・
v node (I), 2.2...actuator, 24'
...Servo motor, 2t...Hydraulic system, 2
g...Open policy detector 3038. Load setting device 3.
2... Proportional calculator 34t... Integral calculator 3z
... Requisition calculator If... Opening adjuster (lI) X... Output characteristic curve of PID calculator X... Output characteristic curve of servo motor FIG, 1 FIG, 3 FIG, 4 □ Time FIG, 5 FIG, 6 -” FIG, 8(a) FIG, 8(b) FIG, 9

Claims (1)

[Claims] (1) PID calculation is performed by inputting a deviation signal between the set output of the speed setter and the lateral ratio output of the water turbine generator, and the opening adjuster and actuator are adjusted based on the calculated output. In an electric speed governor equipped with an opening adjustment loop that follows and controls a servo motor that performs one-closing operation of the hydraulic system, the regulator functions as an amplifier with nonlinear gain characteristics that can compensate for the nonlinear characteristics of the actuator. An electric speed governor characterized by comprising: (2. In the electric governor according to claim 1, the opening adjustment loop includes an opening detector that detects the entire degree of the servo motor, and includes a PID calculation output and an output of the once detector. An electric speed governor configured to once input a deviation signal between The electric controller is constructed by connecting an opening regulator with linear gain characteristics and an opening regulator with nonlinear gain characteristics equipped with an output limiter circuit in parallel, and adding the outputs of these regulators once. formula