JPS6322136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of the Invention The present invention relates to a method for controlling a hydroelectric power plant that controls the output of two or more hydroelectric power plants located in the same water system.

(b) Technical background In general, hydroelectric power plants come in various forms depending on the water system and topography. For example, if there are two ponds upstream and downstream of the same water system, an upper power plant uses water from the upper pond and drops it into the lower pond, and an upper power plant uses water from the lower pond and sends water to the river below. There is a power plant group configuration in which two such power plants have a total of three or more generators. In this case, it is necessary to centrally manage a group of power plants and centrally control the hydroelectric power plants in response to power generation schedule commands from central suppliers.

Conventionally, when controlling such power plants, when there is a power generation output schedule from the power dispatch center, operators decide on the number of units to be operated or the output according to their experience and the actual situation at the time. I was taking it. Recently, a method has been adopted that uses computers to calculate the total output of a group of power plants according to the command. However, in order to keep the water in the pond at the planned water level and continue to operate while maximizing the power generation efficiency that converts water into electricity as effectively as possible, it is necessary to consider the head, the characteristics of each generator, the water level, and the inflow from the river. It must be calculated based on the amount and many other parameters, and quick response cannot be expected. Also, since the volume of the pond is large, it is difficult to accurately measure the amount of inflow from the river, and although complex calculations are required, the effect of this is relatively small.

(c) Purpose of the Invention The purpose of the present invention is to obtain an output value that satisfies the power generation command value determined by the power generation output schedule.
By using relatively simple calculations, we can select a combination of generators that has good power generation efficiency, can keep the water levels of the upper and lower reservoirs within the specified operating water level, and also takes machine life into account, and generates a comprehensive The objective is to obtain a control method for a hydroelectric power plant that enables efficient operation.

(d) Structure of the Invention The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 is a block diagram of a hydroelectric power plant to which the control method of the present invention is applied. Upper pond 1 and lower pond 2 are located in the same water system, and from the upstream side, power plant 3 uses water from upper pond 1 to generate power, and power plants 4 and 5 use water from lower pond 2 to generate power. For convenience, it is assumed that the number of generators in the upper power plant is one, and the number of generators in the lower power plant is two. Normally, when building a power plant, water from a river into a pond is used in a well-balanced manner, and the design is such that the water level in the upper pond is the same during rated operation.

FIG. 2 shows the system configuration of a computer for implementing the control method of the present invention. That is, a process input section 11 is provided to read the water level and generated power, which are the minimum necessary information for control, and an input section is provided in which the operator inputs the lump-sum power generation schedule from the intermediate supply or the information necessary for control. 12, and an arithmetic control section 10 that distributes the power generation output schedule to each generator based on the information taken in from the process input section 11 and the input section 12, and an ALR device 14 based on the results of the arithmetic control section 10. An output section 13 for outputting a command value is provided.

Next, the control method of the present invention will be mainly explained along with the operation of the arithmetic control section. When generating power, the central power supply informs the control center every day of a lump-sum power generation output schedule that is the sum of the outputs of the two power plants. The operator inputs this batch power generation output schedule from the input section 12. The input batch power generation schedule is distributed to individual schedules by the arithmetic and control unit 10 as follows.

The output of the generator varies depending on the shape of the water system and the amount of inflow, but if the generator rating of the upper power station is
The generator ratings of the lower power plant _{in G1} are G ₂ and G ₃ , and their magnitude relationship is now G ₂ = G ₃ , G ₁ > G ₂ , (G ₂ + G ₃ ) >
Let us explain by assuming that there is a relationship of G ₁ . In this case, various combinations of generators can be operated, and the maximum output of the sum of the rated outputs changes as shown in Figure 3. The efficiency of generators varies depending on the type of water turbine, but as shown in Figure 4, the efficiency generally reaches its maximum near the rated value, and the efficiency decreases as the output value decreases. Therefore, when producing the same output, it is more efficient to operate in a combination in which the total rated output matches the required amount of power generation in the power generation schedule. Also, the larger the head difference, the greater the amount of power generated.

On the other hand, as can be seen from FIG. 3, there are cases in which the number of generators operated or the output thereof is large in the upper power plant and in other cases in which the lower power plant is large. In other words, in the case of A, B, D, and G, it is mostly on the lower side;
Cases of C, H, and G are often on the upper side. That is, they alternate as the total output increases. Therefore, when it is unavoidable, efficiency is sacrificed and power is generated by using a combination with a large sum of rated outputs. In this case, the amount of water used in the upper and lower ponds will be changed, so if an imbalance occurs in the water level,
It becomes possible to perform such inefficient operation and adjust the water level.

Next, the case where the generator generates electricity will be explained.
First, when starting power generation from a stopped state, look at the command value g of the batch power generation output schedule, and choose among the combinations of generators that can output this value.
Find the combination that gives the smallest sum of rated outputs.
For example, in the case shown in FIG. 3, combination (d) is selected. Afterwards, start generators G ₂ and G ₃ ,
Issue an output command value. If this output command value is between the operating water levels inside L ₁ and L ₁ ' shown in Figure 5, the above-mentioned value can be selected and output, but if it goes outside L ₁ and L ₁ ' This is because the number of power generating units in either the upper or lower power stations had been operating in an unbalanced state before that, and the generators that can move the water level to the center of L ₁ and L ₁ ' Select the combination with the smallest total rated output. For example, if the lower pond is below L ₁ ' in Figure 5, then
Since generators G ₂ and G ₃ cannot be operated, we have no choice but to choose combination E. After that, the output value that each generator should output is determined. By doing this, the water level will move relatively to the center of L ₁ and L ₁ '. In other words, the generator is transferred from the upper pond to the lower pond.
This is because water is supplied by the operation of _G1 .

Next, when the load change point time comes to change the schedule value during power generation, L ₁ ,
Of course, it is necessary to select the number of generators that will cause the water level to move inside L ₁ ′, but it is not desirable to start and stop the generators frequently from the viewpoint of the lifespan of the machine, so it is necessary to Select a combination that will continue to operate any of the generators that were in use. For example, if a lowering command is received during operation with combination E, either A, C, or D will be selected, and generator G ₃ , which is not in operation, will not be selected. Also, if the same command value continues for a long time,
Since the number of power generators is not changed, water from one pond will be used excessively, resulting in an imbalance in the water level. To prevent this, the operational water level L ₁ ,
L ₂ and L ₂ ′ are provided outside of L ₁ ′ to provide a water level to check if the water level balance has deviated abnormally to alert the operator.

It is clear whether the water level is increasing or decreasing if one side is increasing and the other is decreasing, but both may be increasing or decreasing, so it is difficult to determine which is increasing or decreasing relatively. It's good to judge.

The command value for each generator determined by the arithmetic control unit 10 as described above is transmitted from the output unit 13 to the ALR device 14. The ALR device 14 is a device that always keeps the generated power and the command value constant, and is an automatic load adjustment device.

(e) Effects of the invention As described above, according to the present invention, for a power generation command value, the smallest sum of rated outputs that satisfies the power generation command value is selected, so operation near the rated output is possible. Therefore, it can be operated with high power generation efficiency. In addition, when an imbalance occurs in the water level of the pond, a combination is used to correct the imbalance in the water level of the pond, so the water levels of the upper and lower ponds can be used in a well-balanced manner. Additionally, when the power generation command value changes, the generators that were previously operating will select a combination of generators that will allow them to continue operating.
The number of starts and stops of machines such as water turbines and generators can be kept to a minimum, and the life of the machines can be extended. The hydroelectric power plant control method of the present invention can be effectively applied to power plants whose pond capacity is large enough to generate power for about half a day to a week even when the inflow from the river is zero. Particularly effective.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the positional relationship of the power plants, Figure 2
The figure is a block diagram showing the outline of the hydraulic control device of the present invention, Figure 3 is an explanatory diagram showing that the total output value differs depending on the combination of generators, Figure 4 is a characteristic diagram explaining the characteristics of the generator, and Figure 5 is a diagram showing the difference in total output value depending on the combination of generators. The figure is an explanatory diagram illustrating the operating water level. 10... Arithmetic control section, 11... Process input section, 12... Input section, 13... Output section, 14...
ALR device, 15... generator.

Claims (1)

[Claims] 1 Upper and lower ponds are installed upstream and downstream of the same water system, and the sum of the number of generators in the upper power plant installed in the upper pond and the lower power plant installed in the lower pond is 3 or more. In a method for collectively controlling hydroelectric power plants, when a collective power generation command value is given to these two hydropower plants from a dispatch center, the combination of the generators whose sum of rated outputs satisfies the collective power generation command value Among them, the generator is a combination of the generators that can keep the water level of the upper reservoir and the lower reservoir at a predetermined operational water level when the generator is operated, and the generator has the minimum sum of the rated outputs. When a combination of generators is selected and the sum of output values of the selected generators is controlled so as to satisfy the collective power generation command value, and on the other hand, a change in the combination of generators occurs due to a change in the collective power generation command value. A method for controlling a hydroelectric power plant, which selects a combination of generators that allows the generators that have been operating until then to continue operating, and outputs an output value that satisfies the collective power generation command value.