JPS58181126A - Controlling method of reactive power - Google Patents

Abstract

PURPOSE:To distribute the reactive electric energy on the average, by performing such adjustment that the operation state of each turbine is moved into the optimum operation state zone if the imbalance of the reactive electric energy is caused in combined cycle power generation. CONSTITUTION:If some turbine is stopped to cause the imbalance of the reactive power, the operation state of each turbine is moved to a zone GHI indicating a proper reactive electric energy. Thus, partial charges of the reactive power in all turbines are equal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently controlling reactive power in combined cycle power generation for various operating patterns.

Combined cycle power generation combines a gas turbine and a steam turbine to achieve higher efficiency than conventional power generation. Figure 1 is.

It is a single line diagram showing an example of combined cycle power generation.

In this example, a power generation system is configured by combining one steam turbine (1) and three gas turbines (2) + (3) and (4). and steam turbine (1)
and gas turbine (2) are connected to one busbar (5).

Further, the gas turbine (3) and the gas turbine (4) are connected to another bus bar (6). These two bus lines (51, (
6) is connected to the main mother eel (8) through a three-phase transformer (7).

Note that CBI to CB4 are main circuit breakers, and (9) is a station transformer.

In the combined cycle example given here, three gas turbines and one steam turbine are combined, and the steam turbine outputs 1/3 of the rated output of one gas turbine.

In other words, when all three gas turbines produce rated output, the steam turbine also produces rated output. When the three gas turbines are operating at rated output, the operating state expressed by the active power and reactive power of each turbine is at point aυ in Figure 2.
~α4. Also, when the gas turbine (2) is in a stopped state, the operating states of the other turbines are at point (21) in Figure 3.
~(241, when the gas turbine (3) is in a stopped state is shown by the point fBll~- in FIG. 4. Note that the curve (
16) ~ The bet is the operating capability curve of each turbine, and each turbine can be operated within this range. When all turbines are in rated operation, all turbines are within the capacity curve as shown in Figure 2, but when one gas turbine is stopped, the capacity curve changes as shown in Figures 3 and 4. However, there are disadvantages such as reaching a state where it is impossible to operate, or a state where the reactive power is unbalanced.

This invention was made in order to eliminate the imbalance in reactive power as described above and return it to an operable state. The objective is to provide a control method that can effectively allocate reactive power by taking into account the curve and the operating state of each turbine.

An embodiment of this reactive power charge method will be described below with reference to the drawings. FIG. 5 shows the driving ability curve.

Find the average of the active power and reactive power of all turbines,
Let the point showing this be E. Also above the driving ability curve 111
Let F be the point where both ends A and B of 11 are connected and intersect with the active power axis. Then, there are straight lines l and y that connect E and F. Let G be the point where l intersects the curve BC on the right side of the mafc driving ability curve,
Let G be a straight line m parallel to the active power axis. Ma'ft
The intersection point &I between Cm and the reactive power axis and the intersection point between the reactive power axis and straight line e are assumed to be H.

Now, if any turbine/turbine is shut down and a reactive power imbalance occurs, the reactive power will need to be adjusted for each turbine. That is, the reactive power amount of each turbine must be set to an appropriate value of 11σ depending on the respective active power amount. What indicates this appropriate amount of reactive power is if
Diagonal line zone Q surrounded by L line e, straight line m, and reactive power axis
It is HI. When an imbalance in reactive power occurs, the appropriate reactive power diagram for each turbine should be at a certain ratio to the maximum amount of reactive power, so use GH as a guideline.
An IV zone was established. Therefore, if an imbalance in reactive power occurs, by shifting the operating state of each turbine to this zone, the share of reactive power will be the same for all turbines.

As described above, according to the present invention, reactive power is controlled by considering the capacity curve and the average value of each turbine, so even if one turbine stops, the average reactive power will not be applied to other turbines. This has the effect of making it possible to even out the burden of six months.

[Brief explanation of drawings]

11th. , a single line diagram showing an example of a combined cycle,
Figure 2 is an active power/reactive power diagram showing the operating status of all turbines, and Figures 3 and 4 are active power diagrams showing the operating status of other turbines when one turbine generator is stopped.
Reactive Power Diagram FIG. 5 is an active power and reactive power diagram showing the control method of the present invention. Note that in Figure 1, E represents the average of the active power and reactive power of each turbine, and straight line l is the straight line connecting points F and E, which connect both sides A and B on the upper side of the capacity curve and intersect with the active power axis. m
is a straight line passing through the intersection G of the curve BC on the right side of the capacity curve and the straight line 1 and parallel to the active power axis, and the curve AB CD indicates the driving capacity curve. Agent Makoto Kuzuno

Claims (1)

[Claims] (1) In the capacity curve of combined cycle power generation using multiple turbines, point E indicates the average of the active power and reactive power of each turbine, and both sides A on the upper side of the capacity curve,
A straight line l connecting points F and E that connect B and intersect with the active power axis, a straight line m parallel to the active power axis passing through the intersection G of the curve BC on the right side of the capacity curve and the straight line l, and a straight line m parallel to the active power axis, and the reactive power axis. Reactive power control having an enclosed optimal operating state zone, and when reactive imbalance occurs, reactive power amount is adjusted so that the operating state of each turbine is within the zone. Method.