JPH0556120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a speed governor control device for keeping the output frequency of a water turbine generator, particularly a small capacity water turbine generator, constant.

[Prior art and its problems]

As shown in Figure 6, the basic control system of this type of conventional speed governor is to control the opening degree of the water flow regulating valve, such as the guide vane at the input section of the water turbine, in response to increases and decreases in the generator load. The system is designed to supply water input commensurate with fluctuations. However, when adjusting the opening of guide vanes, etc., there are restrictions on the vane opening/closing time due to various conditions such as the rotation speed increase rate, the iron pipe water pressure increase rate, the power of the vane drive system, and its economic efficiency, as shown in Figure 7 TC. . For example, when the guide vane is closed due to a load reduction as shown in Figure 7, until the predetermined opening GV ₀ is reached, the water turbine will simultaneously supply an excess water input larger than the value corresponding to the new load, as shown in the shaded area. This extra input naturally causes an excessive increase in the rotational speed of the water turbine. Similarly, when the load increases, depending on the rate of increase over time, the rotational speed may drop excessively. In particular, there are restrictions on the amount of load that can be applied suddenly, and it is of course impossible to suddenly apply a full load. The occurrence of these excessive fluctuations is all caused by the response speed of the water turbine input control system such as the guide vane, but this speed cannot be independently increased as described above. Therefore, there is a limit to suppressing transient speed fluctuations during load fluctuations.

[Purpose of the invention]

In view of the above, the present invention suppresses transient speed fluctuations during load fluctuations to an extremely small value compared to conventional devices, and reduces the required power of the water turbine input control system such as guide vanes, thereby achieving a simple and economical configuration. It is an object of the present invention to provide a speed governor control device that is particularly suitable for small-capacity water turbine generators and allows configuration of a drive system such as guide vanes.

[Key points of the invention]

This invention attempts to achieve the above object by the following configuration. In other words, a regulating valve is installed at the inlet of the water turbine of the water turbine generator to adjust the water input.
A simulated load whose load amount can be adjusted is connected to the output of the generator, and the speed of the water turbine generator is controlled by adjusting the regulating valve and the simulated load. a speed regulator that compares a speed detection signal and generates a control signal according to the deviation; a power regulator that adjusts the load amount of the simulated load in accordance with the control signal of the speed regulator; This is a speed governor control device for a water turbine generator, which includes a control signal and a control device that generates an opening/closing command signal to a driving device for the regulating valve in accordance with a control signal and a power or current detection signal of the simulated load. In other words, this invention performs the input/output balance control between the water turbine input and generator output, which is the basics of regulating the speed of a water turbine generator, by not only controlling the water turbine input side but also electrically adjusting the power of a simulated load installed on the generator output side. The aim is to perform control at the same time to extremely improve the speed regulating response during load fluctuations. In other words, by slowly driving the water turbine input control system such as the id vane, the water turbine can simplify the drive system and reduce the drive power, while combining it with a quick-response electric output adjustment system to achieve overall high performance. The aim is to enable speed regulation of small-capacity water turbine generators with quick response and high precision. The simulated load is divided into multiple units, and for each division unit there is a fixed value simulated load group that is connected or disconnected from the generator output side by the simulated load control signal, and a fixed value simulated load group that is larger than any fixed value simulated load unit and is continuous. In addition, the simulated load may be constructed as a simulated load circuit that can be continuously variable controlled over the entire area.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to drawings showing embodiments. 1 to 5 are drawings showing embodiments of the present invention, and FIG. 1 shows the basic control system of the present invention. As can be seen from Fig. 1, in this invention, regarding the responsiveness of regulating speed, the response speed itself of input control systems such as guide vanes is no longer a fundamental characteristic, but the drive speed of guide vanes, etc. is compared to that of the conventional system. It is possible to choose rather late. FIG. 2 shows an example in which the simulated load is composed of only variable parts, and FIG. 4 shows an example in which the same load is composed of n fixed parts and one variable part. Further, FIGS. 3 and 5 show operating modes of each part when the load suddenly changes corresponding to FIGS. 2 and 4, respectively. First, the second
The figure and FIG. 3 will be explained. When the load of generator 2 suddenly decreases from PLr to PL0, the input of water turbine 1
Since PW does not change immediately, the rotation speed of the water wheel begins to increase. The increase in rotational speed is detected by the tachometer generator 5 and applied to the automatic speed regulator 8;
Here, it is compared with the speed setting signal set by the speed setting device 10, a control signal corresponding to the deviation is generated, and a power regulator 6 is added to adjust the load amount of the simulated load 4. As a result, the power (regulator 6 is the simulated load 4
increases the power consumption (load amount) Pd and lowers the rotation speed of the water turbine. In addition, the control device 9 shown as a sequence calculation unit outputs a control signal indicating an increase in the rotational speed of the speed regulator 8 and a detection signal of increased current or power in the circuit of the simulated load 4 detected by the current or power detector. In response, a command signal for closing the guide vane 3 is issued to the servo mechanism 7 that drives the regulating valve 3 such as a guide vane. As a result, the closing operation of the guide vane 3 progresses gradually, and as the amount of water supplied to the water turbine 1 decreases, the water turbine input
PW decreases, and the load amount Pd of the simulated load 4 also decreases accordingly. The final value of the opening degree of guide vane 3 commensurate with the actual load PLo from the initial GVr
When GVo is reached, the closing operation of the guide vane 3 stops, and the load amount Pd of the simulated load 4 becomes zero. Immediately after the load suddenly decreases, the water turbine rotational speed increases △Nu due to transient input/output imbalance due to the overall control time delay of the tachometer 5, speed regulator 8, and power regulator 6, but this occurs in a short period of time. After that, it is kept approximately constant during the above operation. The input/output fluctuation pattern during the above operation is roughly as follows.

Before fluctuation Immediately after fluctuation Pwr＝Plr→ Pwr＝Plr−△Pl＋Pd ∴Pd＝△Pl However, △Pl＝Plr−Plo Only simulated power operation is operating normally Operation completed→Pwr−△Pw＝Plr−△Pl＋Pd→ Pwo＝Plo ∴ Pd=ΔPl−ΔPw ΔPw=Pwr−Pwo Coexistence of simulated power operation and ΔPl=Plr−Plo GV closing operation Pd=O Next, the case where a load is applied and the actual load increases stepwise will be explained.

First, when a load application command is given to the sequence calculation unit 9 by a command device (not shown), this calculation unit 8
outputs to the servo mechanism 7 an opening command signal with an opening degree corresponding to the new actual load amount. In response to this, the guide vane 3 performs an opening operation at a predetermined speed up to the commanded opening GVr. As a result, the amount of water supplied to the water turbine 1 increases and the water turbine input increases, but the actual load remains unchanged and the rotation speed of the water turbine begins to increase.
The speed regulator 8 operates to keep this at a constant speed, and the load amount of the simulated load 4 is controlled via the power regulator 6.
Pd is increased and this simulated load 4 causes the water turbine input
The increase in PW is temporarily borne by the water turbine input PW.
and the balance between the generator output Pg and the generator output Pg is measured. When the guide vane 3 reaches the commanded scheduled opening GVr, apply the actual load that is scheduled to be applied, and change the actual load amount to the planned amount.
When PLr is increased stepwise, the rotational speed of the water turbine begins to decrease, so the load amount Pd of the simulated load 4 is reduced by the operation of the automatic speed regulator 8, and the generator load is rapidly transferred to the actual load. During this period, a decrease in rotational speed ΔNd occurs due to transient input/output imbalance due to delay in operation of the control system, but this is resolved in a short time (see the right half of FIG. 3).

As described above, the present invention exhibits good speed regulating performance even in the most severe step-like load fluctuations, and the responsiveness of the input control system such as guide vanes is no longer a fundamental factor that influences speed regulating characteristics.

Next, the operation of the embodiment shown in FIGS. 4 and 5 will be explained. The operation of this embodiment is basically the same as that of the embodiments shown in FIGS. 2 and 3, but the configuration of the simulated load-related circuit and the accompanying operation mode are slightly different. The variable portion 4a of the simulated load is connected to the output of the generator 1 via the power regulator 6, and the fixed portions 4b and 4c of the simulated load are connected to the generator output via a switch such as a magnetic contactor. The input absorption control is performed. The input to be absorbed is the maximum capacity of the variable part 4a of the simulated load.
When Pdc(max) is exceeded, an appropriate number of fixed portions 4b to 4c of the n simulated loads are selected through the sequence calculation unit 9 so as to obtain the required load amount and are injected in parallel into the variable portion 4a. Conversely, when the absorption amount of the variable portion 4a becomes less than the minimum value Pdc (min), an appropriate number of fixed portions 4b and 4c are separated.

FIG. 5 shows a case where there are two simulated loads on the fixed part. When the actual load suddenly decreases, the simulated loads 4b and 4c of all the fixed parts are first applied together with the variable part 4a. As the closing operation of the guide vane 3 progresses, the load amount Pdc of the variable portion simulated load 4a decreases.
When the load falls below Pdc (min), one of the fixed part simulated loads is disconnected and the load of the variable part is increased again, but as the guide vane continues to close, the load of the variable part simulated load increases again to Pdc (min). ), the remaining fixed partial simulated load is also disconnected, and the excess input is absorbed only by the variable partial simulated load 4a. The subsequent steps are the same as in the case of FIG.

In the case of load application, the variable part and fixed part of the simulated load are combined by the reverse operation.

In principle, the total capacity of the simulated load is selected to be the same as the capacity of the generator 2, so as the generator capacity increases, the capacity of the simulated load also increases, and at the same time, the capacity of the power regulator 6 that adjusts the load amount also increases. It is necessary to do so. It is not advisable to change or increase the capacity of the power regulator 6 according to the generator capacity from various aspects, and if a divided simulated load as shown in the example of FIG. 4 is used, the capacity will be smaller than the generator capacity. power regulator can be used, and an increase in the capacity of the power regulator can be avoided. In addition, the adjusted power consumption for each simulated load during load change ends when the opening degree of the guide vane reaches a value corresponding to the new load. Therefore, each simulated load does not need to be rated continuously, and since its maximum energization time does not exceed the maximum stroke passing time of the control system such as the guide vane, it can be rated for an extremely short time.

In this invention, speed regulation is performed by temporarily passing the turbine input to a simulated load controlled by an electrical control system with quick control response, so that when the generator is fully loaded or shut off, Speed fluctuations can be kept extremely small.

〔Effect of the invention〕

As described above, according to the present invention, the speed is controlled by two control systems: the mechanical control system of the input part of the water turbine such as the guide vane, and the electrical control system using the simulated load. After absorbing the excess water turbine input using a highly responsive simulated load and stabilizing the speed, the water turbine input is adjusted to an amount commensurate with the load using a mechanical control system with a slow response speed such as guide vanes. , it is possible to suppress transient speed fluctuations during load fluctuations to an extremely small level. Since there is no need to increase the response speed of the control system for the guide vanes, etc., the output of the servo mechanism that drives the guide vanes can be reduced, and the structure of this control system can be made simpler and more compact. It also has the effect of being able to provide high-performance small-scale hydroelectric power generation equipment at low cost.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, in which FIG. 1 shows its basic control formula, and FIGS.
The figures are block diagrams showing different embodiments, Figures 3 and 5 are time charts corresponding to Figures 2 and 4, respectively, and Figures 6 and 7 are conventional examples. FIG. 6 shows its basic control formula, and FIG. 7 shows its time chart. 1... Water turbine, 2... Generator, 3... Water turbine input adjustment section (guide vane or inlet valve), 4... Simulated load, 4a... Movable side simulated load, 4b, 4c...
Fixed side simulated load, 5... Tachometer, 6... Power regulator, 7... Electric or hydraulic servo motor, 8...
automatic speed regulator, 9...sequence calculation section, 10
... Speed setting device, 11 ... Power or current detector, 12, 16 ... Current transformer, 14, 15 ... Magnetic contactor.

Claims (1)

[Claims] 1. A regulating valve for adjusting the water input is provided at the inlet of the water turbine of the water turbine generator, and a simulated load whose load amount can be adjusted is connected to the output of the generator. A speed regulator that compares a preset speed setting signal with a speed detection signal of the water turbine generator and generates a control signal according to the deviation, and a speed regulator that generates a control signal according to the deviation thereof. a power adjustment device that adjusts the amount of load of the simulated load; and a power adjustment device that generates an opening/closing command signal to a drive device of the regulating valve in response to a control signal of the speed adjustment device and a power or current detection signal of the simulated load. A speed regulating control device for a water turbine generator, characterized by comprising a control device.