JPS62203519A - System voltage controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a system PrT1 using an on-load tap-changing transformer or the like.
．． This invention relates to a system voltage control device that automatically controls voltage.

(Prior art) As an example of this type of device, there is a
No. 9-209759 and Japanese Patent Application No. 59-209760.

This device uses a digital circuit to create the AVR characteristics at the inverse limit required for system voltage control, thereby realizing the integration of the AVR function and control circuit with a digital circuit, making it more compact and
It has achieved high performance.

(Problem to be Solved by the Invention) However, the method for setting the voltage, operating time, and dead zone in this device is the same as in previous AVRs, and the operator first sets the reference voltage setting value (VOLT), Time setting value (
Seconds) and dead zone setting value (%) are substituted into the AVR characteristic formula at the inverse limit, and an appropriate value is obtained from the graph.
There was a problem that it took a long time to set up.

In addition, once the settings are completed, the setting values displayed on the device are only the values indicated by the switch.9 For example, reference voltage 1 set value 110■, operating time setting value 40 seconds, dead; i+'' setting value ±1% It is only indicated by the value of 3 points, and it is impossible to understand what kind of anti-time characteristic is actually present unless you refer to the operating tool's instruction manual.

The purpose of the present invention is to provide an AVR at the inverse limit required for system a voltage control.
Characteristics are shown as lines (graphs) so that the operator can understand them at a glance, and the current voltage value is displayed on the same screen, informing the voltage movement and making it easy to consider settings. An object of the present invention is to provide a procedural voltage control device that achieves improvements.

[Structure of the invention]

(Means for Solving the Problems) As shown in FIG. 1, the system control device according to the present invention has a preset operating time setting value and an AVR characteristic for each operating time of a certain time width determined by If the value is stored in the area for each operating time of the AVR characteristic table, the input system voltage and the preset reference voltage are subtracted for each operating time to find the deviation at that point, and this deviation is calculated from the previous time. means (a) for calculating a voltage value by adding the integrated value of the deviation up to the operating time and dividing the result by the operating time up to the current time, and storing this in a corresponding area of the storage buffer in an area for each operating time; Means for comparing the values stored in mutually corresponding areas of the AVR characteristic table and the voltage value storage buffer, searching for the presence or absence of a comparison result of the AVR characteristic characteristic value pressure voltage value, and generating a control output if there is a comparison result. C, a display 10 capable of displaying graphs based on the vertical and horizontal axes, and displaying the contents of the AVR characteristic table and the voltage value storage buffer on the display 10 on the vertical and horizontal axes. display control means 8 for setting one of the voltage values to the respective operating voltages and setting the voltage value to the other voltage value and displaying the voltage value.

(Function) In the present invention, the contents of the AVR characteristic table are displayed as a line diagram (graph) on the display 10, and the contents of the voltage value buffer are displayed on the same screen as the above A and VR characteristics,
This makes it possible to view the relationship between the current system voltage state and AVR characteristics at the same time.

(Example) The present invention will be described in detail below with reference to an example shown in the drawings.

FIG. 2 is a system diagram when one on-load tap switching converter is used, and shows the exchange of signals with the system voltage control device.

In the figure, LRT is an on-load tap switching transformer, and a breaker 52S is connected to the secondary side.

The breaker 52S is connected to the bus line BtJ], and this bus line BU
S includes the distribution line 1 and the disconnector 52F1. ..., 52FN is connected.

Further, a potential transformer PT is connected to the secondary side of the on-load tap change transformer, and this secondary side is input to the system voltage control device AVR. Also.

1 indicates that a rising and falling signal is given from the system voltage control device AVR to the on-load tap switching transformer LRT. 2 indicates that the voltage value signal on the secondary side of the on-load tap change transformer LRT is given to the grid voltage control device 1AVR.

Next, the configuration and input/output relationship of the system voltage control device AVR will be explained using FIG. 3 is a well-known microcomputer, which basically consists of a CPU, 4 degrees ROM, 5
It is composed of RAM 6. ROM5 has CP
A program is written to control U4. CPU4
In accordance with this program, necessary external data is taken in from the analog input device (hereinafter referred to as analog input) 7, or data is transferred to and from the RAM 6 for arithmetic processing, and processed as necessary. Data dot matrix liquid crystal display interface 8a
(corresponding to display control means 8 in FIG. 1) or output to relay out 9.

Voltage value data is input via analog input 7, and for this purpose input point AI is connected to the secondary side of potential transformer PT shown in FIG.

The set value data is input via the analog input 7 in the same way as the voltage value data. That is, sliding resistors R1, R2°R3 are connected to the external interface power supply E, and these are connected to the input point AI2. A1. ．． AI
, respectively.

For the purpose of explanation, AI2 is the reference voltage setting value (the normal setting range is 1
00-120), A1. The operating time setting value (
The normal setting range is about 40 to 200 seconds), and AI4 is set to the dead zone setting (the normal setting range is ±1 of the reference voltage setting value).
~±4%). The method of inputting the set value is not limited to the variable voltage value using the sliding resistor as described above, but may also be a count input using digital input.

The calculation results are outputted via a dot matrix liquid crystal display interface 8 and a relay out 9. That is, the dot matrix liquid crystal display interface 8a connects the driver 1 to the matrix liquid crystal display 10 connected thereto.
It has a RAM area corresponding to each dot of a (corresponding to the display 10 in FIG. 1).

It stores the ON or OFF status of each dot specified by the CPU 4 and outputs it to the outside. This output causes each dot on the dot matrix liquid crystal display 10a to become black or transparent. Furthermore, when the contact ROL of the relay out 9 is turned on, it outputs a tap-up command to the corresponding on-load tap change transformer LRT. Also,
When the contact RO2 is turned on, it outputs a tap lowering command to the tap switching transformer LRT when a snack is loaded.

Next, an example of display and an example of calculation according to the present invention will be explained using FIGS. 4 and 5. FIG. 4 shows an example of a display, and FIG. 5 shows a buffer for storing each data. 1 in Figure 5
5 is an AVR characteristic table, which corresponds to the values of the polygonal line 12 for each operating time in FIG. This AVR characteristic is calculated by the following equation.

Here, the operating time is 4 @, y work in Figure 5, y2 °...
・*Corresponding to yzo, (operating voltage value - reference voltage value),
In other words, the AVR value is shown in Figures 4 and 5 (7)
l X Ax t..., xA□. The dead zone corresponds to Dt in FIG. Furthermore, when the operating time setting value is changed, the polygonal line 12 moves in the vertical direction. Further, the base $ voltage value corresponds to the origin of the V axis.

Here, the reference voltage value, dead band, and operating time setting value are input through analog input 7 as described in the notes. The AVR characteristic value xA~X^2° for each operating time y1~y2° of the time width is calculated and stored in the area of the corresponding operating time in the AVR characteristic table 15.

In Figure 5, in the voltage value storage buffer, each operation time y□~y
2. Voltage value X , , is stored. This voltage value X is ~XBz. is each operation time y of the polygonal line 14 in FIG.
It corresponds to a value of 0 to 'lzo. In Fig. 5, reference numeral 17 is a comparison price value buffer, which has an AVR of y° to y2° during each operation.
Comparison results XOL~XO2° between characteristic values XA□~XAZ and voltage values XB□~XB2o are stored. Note that in Figures 4 and 5, to simplify the explanation, x > O+ y)
Only the O-lower judgment was made.

Next, the program written in the ROM 5 will be explained according to flowcharts 1 to 6 in FIG. When the program starts, the microcomputer 3 first reads the reference voltage value, operating time setting value, and dead zone value shown in FIG. 3 from the analog input 7 (step 0). The AVR characteristic characteristic value X-xA2o is calculated from this input setting value and stored in the AVR characteristic table 15 (step 2). Next, points on the VT coordinates of the dot matrix liquid crystal display that correspond to the characteristic values stored in the calculated AVR characteristic table are displayed in black (step 2).

Next, from analog input 7 to transformer L shown in Figure 2.
R72 Read the next voltage value (step ■).

Next, the base voltage value is subtracted from this read voltage value to find the deviation from the reference voltage. If the operating time is y at this point, divide the above deviation by the operating time y1 to obtain the voltage value XB.
t is determined and stored in the corresponding area of the voltage value storage buffer 16. Also, if the reading time is operating time y2, calculate the integrated value of the deviation at that point (current deviation + previous deviation), divide this by operating time yz (integrated value), and obtain the voltage value x
Find B□ and store it in the corresponding area.

Similarly, for each operating time y, ~ y2°, calculate the integrated value of deviation up to that point (current deviation + integrated value of deviation up to the previous time), and calculate this value for the operating time yn (n
= 1 to 20) (calculated value) divided by the voltage value XB3 to XB
2o is determined and stored in the corresponding area as shown in FIG. 5 to create the voltage value storage buffer 16 (step ①).

Next, the value in the voltage value storage buffer 16 and the value in the AVR characteristic buffer 15 are compared (subtracted), and the resulting value is stored in the comparison value storage buffer 17 (step ■■). In other words, specifically x. ,=xA□-X, ,x,=xA, -XB2.・
-Xc2o=XA2o-XB2. Execute the calculation.

Next, the voltage value obtained in step (2) is compared with the dead zone value, and if the voltage value is less than the dead zone value, proceed to step (2), and if the voltage value≧the dead zone value, proceed to step 11.

In step (2) and step (2), the voltage value buffer and comparison value buffer obtained above are respectively cleared.

In step 10, the origin is displayed as a printing force to indicate that the voltage value is smaller than the dead zone value. The flicker pattern at the origin is shown by point 13 in FIG.

Next, in step O, the sign of the comparison value obtained in step ■ is checked, and if the comparison value>0, the process proceeds to step O, and if the comparison value≦◎, the process proceeds to step 0.

In step O, the point on the VT coordinate of the dot matrix liquid crystal display 10a corresponding to the current operating time and voltage value is displayed in black. An example of the display in step O is v in Figure 4.
Bi, ■8□, ...v8□.

In step O, similarly to step O, a dot matrix liquid crystal display 10a corresponding to the current operating time and voltage value is displayed.
The point on the VT coordinate of is displayed in black. An example of the display at step O is shown as vBm in FIG. 4. Next, at step O, a lowering signal is output from the relay out 9 to the load tap converter LRT. Next, in step O and step O, the voltage value buffer and comparison value buffer obtained above are cleared, respectively.

Next, in step O, in preparation for the next display, the already displayed voltage value V Blr V 82 +...vo7
In step O, the origin is displayed with a flicker to indicate that it has returned to the initial state. Step O above,
After executing step qJ and step O, proceed to step ◎.
Repeat the program.

By executing the above program, it is possible to display the inverse time characteristic of AV and the current voltage value. Although FIG. 4, FIG. 5, and FIG. 6 are explanatory diagrams for making a downward determination, an upward determination can also be made in the same manner.

In addition, in FIGS. 4, 5, and 6, the operation time interval is set large and up to T2o to simplify the explanation, but
By making this smaller and connecting each point with a straight line,
It is possible to make the line smoother, and an example of this is shown in FIG. The voltage value display extends from the origin in the direction of the arrow, and when it exceeds the AVR characteristic value, it indicates that it has returned to the origin again.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to display the AVR characteristics and the locus of the current and previous voltage values, which allows the operator to understand the set values at a glance, and also to display the voltage values. It becomes easier to consider the settings by plotting the trajectory of .

[Brief explanation of drawings]

Fig. 1 is a functional block diagram showing the 4W configuration of the present invention, Fig. 2 is a system diagram showing an embodiment of the control device for the on-load tap change transformer according to the present invention, and Fig. 3 is the same as shown in Fig. 2. FIG. 4 is a graphical characteristic diagram showing a display example in the present invention, FIG. 5 is a diagram showing a buffer used in the present invention, and FIG. 6 is a flowchart showing an example of a program used in the present invention. 7 are graph characteristic diagrams showing other display examples according to the present invention. LRT...Tap switching transformer on load PT...Instrument transformer 52S...Generic secondary circuit breaker 52F1~52FN...Distribution line breaker l...LR
T control signal 2...Voltage signal 8...Display control means 10...Display device 12...AVR characteristic 14...Voltage value locus 15...AVR characteristic table 16...Voltage value storage buffer 17... Comparison value storage buffer agent Patent attorney Nori Chika Ken Yudo Hirofumi Mitsumata Figure 1 Figure 2 AVR Figure 3 / J Rit Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] Based on the preset operating time setting value and dead operating time setting band value, an operation with a constant time width determined by operating time = operating time setting value/(AVR characteristic value - dead band value) A where the AVR characteristic values for each hour are stored in the area for each operation time above.
From the VR characteristic table, subtract the input system voltage and preset reference voltage for each operating time above to find the deviation at that point, add this deviation to the cumulative value of deviation up to the previous operating time, and add the result. means for calculating a voltage value divided by the operating time up to the current time and storing it in a corresponding area of a voltage value storage buffer having an area for each operating time; It compares the values stored in the areas where the AVR characteristic value ≦ the voltage value, and searches for the presence or absence of a comparison result where AVR characteristic value ≦ voltage value. a display capable of displaying the contents of the AVR characteristic table and the voltage value storage buffer; one of the vertical and horizontal axes of the display is set to the respective operating voltages, and the other is set to the voltage; A display control means for displaying the value. System voltage control device equipped with