JPH01295699A - Governor control apparatus - Google Patents

Abstract

PURPOSE:To enable a control system to be formed with ease by a structure wherein discharge limitation is performed by suppressing a generator output step by step. CONSTITUTION:A contact point Y is switched on at timing of a working start and this state will be maintained for a fixed times. A generator output at this point of time is supplied to a discharge limiting value calculating section 10. The discharge limiting value calculating section 10 calculates a generator output at T times later on the basis of the inputted generator output, calculates a discharge limiting value PL according to the calculated value, and supplies the value PL to a discharge limiting value memory 11. A low-pass gate 13 selects one with a minimum value out of an output setting value PS, the discharge limiting value PL, and an authorized maximum output, and outputs the selected one as a reference value PS'. Further, a load limitation device ALR controls a load limiting electric motor 9 in accordance with the comparison result between the reference value PS' and an generator output PG. Furthermore, the contact point Y is switched on for every constant duration, and correspondingly the content of the discharge limiting value memory 11 is updated.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a governor control device for keeping the rotational speed (frequency) of a water turbine generator constant, and particularly to a governor control device with a discharge limiting function.

B1 Summary of the Invention The present invention has a function of calculating the deviation between the detected output value and the output setting value of a water turbine generator, and when the absolute value thereof is greater than a certain value, drives a pulse generation circuit and operates a load limiting motor. The governor control device includes a discharge limit value calculation unit that calculates a discharge limit value based on a river flow rate increase curve due to discharge in which the flow rate used for power generation is replaced with the generator output, a discharge limit value memory, an output setting value, and a discharge limit value. A low-pass gate is installed that selects the minimum value from among the values and the maximum allowable output and outputs it as a reference value to be compared with the detected value, and a contact and breaker auxiliary contact that turns on and off for a certain period of time at the start of use. The detected value and the reference value are selectively read into the discharge limit value calculation unit so that the detected value is input at a certain time from the start of use, while the detected value and the reference value are inputted at a certain time from the start of use. By reading the discharge limit value into the memory when the discharge limit value has elapsed, the contents of the memory are updated at predetermined time intervals, and discharge restriction is accurately performed by stepwise suppression of the generator output.

C0 Conventional technology In hydroelectric power generation, the rotation speed of the water wheel is controlled to a specified value,
A governor is used to maintain a constant frequency.

The governor is attached with a load limiter (ALR) and the like that determines the upper limit of the opening direction (load increase) of the servo motor. An example (block diagram) of the configuration in that case is shown in FIG.

In FIG. 3, ■ is a water turbine generator, 2 is a water turbine, 3 is a governor, 4 is a converter that detects the output of the generator 1 and converts it into a feedback signal P6, and 5 is a detected value (feedback signal pc). A circuit that compares the output setting value P8 and calculates the deviation; 6 is a discrimination circuit that determines in which range the deviation is; 7 is a pulse generation circuit; 9 is a load limiting motor, which is driven according to the discrimination result. The pulse generating circuit 7
controlled by the output pulse of

In addition, when configuring an ALR with a discharge restriction, an upper limit of the mark time period of the pulse is set so that the pulse generating circuit 7 does not receive a continuous command.

Problems to be solved by the D1 invention However, with discharge restriction using such an analog circuit,
High accuracy cannot be expected.

Incidentally, the discharge restriction refers to a restriction on the rise in river water level based on the River Act, and for example, it is necessary to suppress the rise in river water level to 30 cx/30 minutes. If this is shown graphically, the relationship between time t and river water level is proportional as shown in FIG. 4, but if the shape of the river is taken into consideration, the flow rate will be as shown in FIG. 5.

On the other hand, the generator output P is given by: P=9.8HQη7·η6, where the effective head is H1 and the flow rate is Q. Therefore, the flow rate can be uniquely converted to the generator output. In order to combine generator control and discharge restriction, it is easiest to assemble a control system using P. This is shown in FIG.

FIG. 6 can be converted into FIG. 7 for control purposes.

80 Means for Solving the Problems The present invention calculates the deviation between the output detection value and the output setting value of the water turbine generator, and when the absolute value is above a certain value, drives the pulse generation circuit to operate the load limiting motor. In a governor control device equipped with a function to A low-pass gate that selects the minimum value from among values, discharge limit values, and authorized maximum output and outputs it as a reference value to compare with the detected value, and a contact and circuit breaker that turns on and off for a certain period of time at the beginning of use. A manual switching circuit configured to selectively read the detected value and the reference value into the discharge limit value calculating section using an auxiliary contact so that the detected value is inputted at a certain time from the start of use, and when calculating a new discharge limit value. , or a memory input circuit that turns on only for the time required to read the discharge limit value into the navigation memory when a certain period of time has elapsed since the previous calculation, and discharge restriction is carried out by stepwise suppression of the generator output. It is something to do.

21 Action When the detected value is read into the discharge limit value calculating section by the on/off operation of the contact of the human power switching circuit, the output of the curve corresponding to the input after a predetermined time is calculated as the discharge limit value. The calculation results are read into the memory via the memory input circuit.

In this case, the memory contents are updated at predetermined time intervals by the operation of the memory input circuit.

The discharge limit value is input to the low-pass gate together with the output setting value, and the minimum value is selected.

This is output as a reference value, and compared with the detected value to take the deviation. Appropriate control is performed depending on the magnitude of this deviation.

G. EXAMPLES The present invention will be explained in detail below based on illustrated examples.

FIG. 1 shows an embodiment of the present invention, in which 1 is a water turbine generator, 2 is a water turbine, 3 is a governor, 4 is a converter that detects the output of the generator I and converts it into a feedback signal Pa; 5
1 is a circuit that detects a deviation by comparing the reference value Bi and the detected value (feedback signal PG), 6 is a discrimination circuit that determines in which range the deviation is, 7 is a pulse generation circuit, 8 is a traffic jam detection circuit, and 9 is a circuit that detects a deviation. A load limiting motor, IO is a discharge limit value calculation unit, II is a discharge limit value memory, 12 is an output setting value memory, and 13 is a plurality of inputs, such as output setting value P9, discharge limit value PL, and authorized maximum output. a low-pass gate that selects the minimum value input and outputs it as a reference value P's;
5.2G is a circuit breaker auxiliary contact, and X, Y, and Z are relay contacts. Contact X is turned off when a traffic jam is detected and when the device is not in use, and is provided on the output side of the pulse generating circuit 7. The contact point Y sends the detected value P6 to the discharge limit value calculation unit 10.
Alternatively, it is a switching contact for manually inputting the reference value P's, and the detected value Pc is read through the a contact, and the reference value P's is read through the b contact and the circuit breaker auxiliary contact 52G. This contact Y is connected when this device is in use and the circuit breaker auxiliary contact 52G
After turning on, the a contact is turned on for a certain period of time.

In addition, the contact X is for reading the discharge limit value PL into the memory 11, and the calculation unit IO calculates the new discharge limit value P.
When i is calculated, or when one hour as shown in FIG. 7 has elapsed since the previous calculation, it is turned on only for the time required to read the discharge limit value PL into the memory 11.

Next, the operation will be described. The point of start of use is either when the main engine is put in parallel after starting, or when the main engine is in operation and the water system is excluded from being used according to an operator's instruction. At this time, it is sufficient to proceed to the next step using the current output of the generator 1 as a reference, and this is realized by the operation of the contact Y. That is, the contact Y is turned on for a certain period of time (several seconds) at the timing of starting use. Thereby, the generator output at this point is given to the discharge limit value calculation section 10.

In the discharge limit value calculation unit IO, the function shown in FIG. 6 is calculated using the following method. For example, as shown in FIG. 2, time 1. A value Pa2 at time t, T hours after, is calculated. This calculated value is read into the discharge limit value memory 11 via contact Z. Since the contact Z is turned on for a certain reading time from a predetermined time, the contents of the discharge limit value memory 11 are updated every T time. That is, the discharge limit value PL changes stepwise.

This discharge limit value Pt is input to the gate I3 together with the output setting value P8 and the authorized maximum output. Here, the smallest value is selected and becomes the reference value P's. This reference value Ps' is the detected value P. The deviation is determined by comparing the values and the level is determined. Based on the result, the pulse generation circuit 7 is controlled, the load limiting motor is driven, and the generator output is controlled.

By the way, the reference value P's may be input to the discharge limit value calculation unit 10. This is because Pa'=P's does not necessarily hold within the control dead zone of ALR, so it is not desirable for control to always use the detected value Pc as a reference, and there is a risk of a step increase each time the control is performed. It is. For this reason, the contact Y becomes the b contact after the first reading into the discharge limit value memory is performed. With this method, the output increases in the same step every time under the same conditions.

Note that the discharge restriction is a restriction on an increase in flow rate, but is not a restriction on a decrease in flow rate. This is low pass gate 13
realized by

Effects of the H0 Invention As described above, according to the present invention, discharge restriction is realized as stepwise suppression of the generator output, so the control system can be easily configured. Furthermore, the steps can be set at any time. Further, the discharge limit value can be set at an arbitrary curve and take the most efficient rising step, and the discharge restriction function can be accurately performed. Furthermore, there is an advantage that the ALR function can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the governor control device according to the present invention, FIG. 2 is an explanatory diagram of the operation of the discharge limit value calculating section in the same embodiment, and FIG. 3 is a block diagram showing a conventional example. FIGS. 4 to 7 are characteristic diagrams for explaining discharge restriction. 1... Water turbine generator, 2... Water turbine, 3... Governor,
4... Converter, 5... Deviation detection section, 6... Discrimination circuit, 7... Pulse generation circuit, 8... Traffic jam detection circuit,
9... Load limiting motor, lO... Discharge limit value calculation unit, 11... Discharge limit value memory, I2... Output setting value memory, 13... Low pass gate, 52G... Circuit breaker Auxiliary contact, X. Y and Z...Relay contacts.

Claims (1)

[Claims] (1) In a governor control device that has the function of calculating the deviation between the detected output value and the output setting value of a water turbine generator, and when the absolute value thereof exceeds a certain value, drives a pulse generation circuit and operates a load limiting motor. , a discharge limit value calculation unit that calculates a discharge limit value based on a river flow rate increase curve due to discharge in which the flow rate used for power generation is replaced with a generator output; and a discharge limit value memory;
A low-pass gate that selects the minimum value from the output set value, discharge limit value, and maximum allowable output and outputs it as a reference value to be compared with the detected value, and a contact that turns on and off for a certain period of time at the beginning of use. an input switching circuit configured to selectively read the detected value and the reference value into the discharge limit value calculating section using the circuit breaker auxiliary contact so that the detected value is inputted at a certain time from the start of use; It is characterized by comprising a memory input circuit that is turned on during calculation or when a certain period of time has elapsed since the previous calculation, and is turned on for the time required to read the discharge limit value into the memory, and discharge is restricted by stepwise suppression of the generator output. Governor control device.