JPH05146075A - Power flow controller - Google Patents

Abstract

PURPOSE:To obtain a power flow controller in which connecting bus of load can be modified automatically so that the value of power flow passing through a bus link line approaches to zero. CONSTITUTION:A decision is made whether the value of power flow passing through a bus link line 10 is within a previously stored allowable value. When it is not within the allowable value, a regulating power value is determined based on the difference between the power flow value and the allowable value in order to bring the power flow value close to zero. A load 15 for modifying the connecting destination is then selected based on the regulating power value, the polarity thereof, power consumption value of each load, and connecting state of a double-throw disconnector 18 thus modifying the connecting destination of thus selected load 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power flow control for controlling a power flow in a power distribution system in which power is supplied to a load by a double bus of a power receiving bus from a power company and a power generating bus from a private power generation facility. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, there is no power flow controller of this type, and the power flow is controlled manually by an operator. Hereinafter, control of power flow by an operator will be described.

FIG. 3 is a system diagram showing a power distribution system disclosed, for example, in Japanese Patent Publication No. 22610/1990.
1 is a power company, 2 is a power receiving protection system that detects an accident in the power receiving system, 3 is a power receiving circuit breaker, 4 is a transformer, 5 is power receiving 2
Next breaker, 6 is a power receiving bus that is supplied with power from the power company 1, 7 is a private power generation facility, and 8 is a power breaker (GC)
B), 9 is a power generating bus supplied with electric power from the private power generation facility 7, 10 is a bus connecting line connecting the power receiving bus 6 and the power generating bus 9, 11 is a bus breaker (CB), and 12 is an instrument transformer. , 13 is a current transformer for measuring instrument, 14 is a power flow meter for measuring the value of power flow passing through the bus connecting line 10, 15 is a load, 16 is a load breaker (L-CB), 17 is a load 15
Power consumption measuring instrument for measuring the power consumption value of
A double throw disconnector (DS) for connecting 5 to either the power receiving bus 6 or the power generating bus 9.

Next, the operation will be described. It is assumed that all of the power receiving circuit breaker 3, the power receiving secondary circuit breaker 5, the power generation circuit breaker 8 and the mother circuit breaker 11 are closed, and the private power generation equipment 7 is in an operating state. Further, the relatively important load 15 of the plurality of loads 15 is connected to the power generation bus 9 by the double disconnecting switch 18, and the relatively unimportant load 15 is the double disconnecting switch 1.
It is connected to the power receiving bus 6 by 8.

When the power receiving protection system 2 detects an accident in the power receiving system in such a connected state, the power receiving breaker 3 and the mother breaker 11 are tripped for power receiving protection. As a result, the load 15 connected to the power receiving bus 6 is out of power, and the load 15 connected to the power generating bus 9 is continuously supplied with power from the private power generation facility 7.

Immediately before the main circuit breaker 11 trips, the flow of the power flow passing through the bus connecting line 10 is in the direction (small power generation) flowing from the power receiving bus 6 side to the power generating bus 9 side. In this case, immediately after the mother circuit breaker 11 is tripped, the output power of the private power generation equipment 7 becomes insufficient, so that the frequency of the power generation bus 9 decreases. On the contrary, when the flow of the power flow is in the direction from the side of the power generation bus 9 to the side of the power reception bus 6 (large power generation), the output power of the private power generation equipment 7 immediately after the tripping of the main circuit breaker 11 Is excessive, the frequency of the power generating bus 9 becomes high.

In any case, the speed governor of the prime mover of the private power generation equipment 7 operates and is controlled to have a predetermined frequency. However, immediately before the trip, the power flow value passing through the bus connecting line 10 is If it is large, the frequency fluctuation of the power generation bus 9 immediately after the trip becomes large, which adversely affects the system. Therefore, in order to reduce such frequency fluctuation, it is necessary to make the power flow value passing through the bus connecting line 10 as close to zero as possible.

However, conventionally, there is no device for controlling such a power flow, so that the operator constantly monitors the power flow value detected by the power flow measuring device 14 and operates the double-throw disconnecting switch 18 as necessary. By doing so, the connection bus bar of the load 15 was changed.

[0009]

In the past, there was no device for controlling the power flow, so that in order to continue stable operation of the power distribution system, the operator constantly monitors the power flow value passing through the bus connecting line. Since the connection bus of the load must be changed as necessary, the burden on the operator is large, and the operator sometimes overlooks the problem, resulting in lack of stability of the power distribution system.

The present invention has been made to solve the above problems, and can automatically change the connecting busbar of a load so that the power flow value passing through the busbar connecting line approaches zero. The purpose is to obtain a power flow control device that can be used.

[0011]

According to a first aspect of the present invention, there is provided a power flow control device for determining whether or not a power flow value passing through a bus connecting line is within a prestored allowable value.
If it is not within the allowable value, the adjusted power value is calculated from the difference between the power flow value and the allowable value so that the power flow value approaches zero, and the adjusted power value, the polarity of the power flow value, and the power consumption value of each load Also, the load whose connection destination is to be changed is selected based on the connection state of the double throw disconnecting switch, and the connection destination of the selected load is changed.

The power flow controller according to a second aspect of the present invention is, in addition to the means for changing the connection destination of the load selected according to the first aspect of the invention, the connection state of the load with the changed connection destination. Is displayed, and an alarm is displayed when the connection is not changed normally.

[0013]

In the power flow controller according to the present invention, the load whose connection is changed is selected based on the regulated power value, the polarity of the power flow value, the power consumption value of each load, and the connection state of the double disconnector. However, by providing the connection destination changing means for outputting the change command to the load connecting means, the connection destination of the load is automatically changed according to the magnitude of the power flow value passing through the bus connecting line.

In the power flow controller according to the second aspect of the present invention, since the display means is provided, the connection state of the load whose connection destination has been changed is displayed, and the connection change has been normally performed. If not, an alarm will be displayed.

[0015]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a power flow controller according to an embodiment of the present invention. In the figure, 19 is a power generation bus supplied with power from a power company 1 or a power generation system supplied with private power generation equipment 7. A load connecting circuit (load connecting means) for controlling the double disconnecting switch 18 so as to respectively connect a plurality of loads 15 to any of the busbars 9, 20 is a busbar connecting line 10 for connecting the power receiving busbar 6 and the power generating busbar 9 to each other. An input circuit (input means) for inputting the passing power flow value and the power consumption value of each load 15 from the power flow measuring device 14 and the load power consumption measuring device 17, respectively, and inputting the connection state of each double-throw disconnecting switch 18. , 21 are storage circuits (storage means) for storing the allowable value of the power flow value passing through the bus connecting line 10.

Reference numeral 22 determines whether or not the power flow value input by the input circuit 20 is within the allowable value stored by the storage circuit 21, and if it is not within the allowable value, the power flow value should be brought close to zero. The adjusted power value is obtained from the difference between the power flow value and the allowable value, and the connection destination is determined based on the adjusted power value, the polarity of the power flow value, the power consumption value of each load 15 and the connection state of the double disconnecting switch 18. Selecting the load 15 to be changed and outputting a change command to the load connecting circuit 19; 23 is a connection state of the double-throw disconnecting switch 18; Confirmation means for confirming whether or not 24 is an arithmetic circuit having connection destination changing means 22 and confirmation means 23, and 25 is for displaying the result confirmed by the confirmation means 23, and when the connection is not changed normally. Alarm A Shimesuru display device (display means).

Next, the operation will be described with reference to the flowchart of FIG. First, the mother breaker 11 and the power generator breaker 8
The open / closed state is input (step ST1), and it is determined whether or not both are closed (step ST2). When any one of them is in the open state, the parallel system is not used, so that the flow control in the bus connecting line 10 is not performed and the process returns to step ST1. On the other hand, when both are in the closed state, each double-throw disconnector 1
8 connection state (whether the connection destination of the double disconnecting switch 18 is on the power receiving bus 6 side or the power generating bus 9 side), the connection state of each load breaker 16 and the bus connecting line 10 The power flow value and the power consumption value of each load 15 are input to the input circuit 20.
(Step ST3, step ST4).

Next, the arithmetic circuit 24 determines whether or not the power flow value input to the input circuit 20 is within the allowable value (step ST5). For example, the tolerance is ± 1
If the power flow value is 0 MW and the power flow value is 5 MW, it is within the range. Here, if it is within the allowable value, the power flow control is not necessary, and the process returns to step ST1. On the other hand, if it is not within the range, it is necessary to control the power flow, and the power flow is controlled as shown below.

First, the arithmetic circuit 24 obtains an adjusted power value (a control amount required to make the power flow value zero) from the difference between the power flow value and the allowable value (step ST6). Adjusted power value = | power flow value |-| permissible value | Next, the power flow direction is determined from the polarity of the power flow value (step ST7). The flow direction is from the power receiving bus 6 side to the power generating bus 9
If it is in the direction of inflow (small power generation), the load 15 for changing the connection destination from the power generation bus 9 to the power reception bus 6 is selected as follows (step ST8), and conversely the tidal current direction is from the power generation bus 9 side. If it is in the direction of flowing into the power receiving bus 6 side (power generation is large), a load whose connection destination is changed from the power receiving bus 6 to the power generating bus 9 is selected (step ST9).

A procedure for selecting the load 15 whose connection destination is changed will be described. For example, the regulated power value is 12 MW (small power generation), and the load 15 connected to the power generation bus 9 includes a load A (power consumption value 5 MW) and a load B (also 4).
MW), load C (also 3 MW), load D (also 3 M)
W) and the load E (also 2 MW), the combination of the loads A to E is considered so as to be closest to the adjusted power value (10 MW). Here, as the combination, load A (5 MW) -load B (4 MW) -load C (3 M
W) ---- Load A (5 MW) -Load B (4 MW) -Load D (3 M
W) --- There are two possible ways, but considering the case where there are two or more combinations like this, the priority order of the load C and the load D is determined in advance, and the load C is prioritized over the load D. If the ranking is high, the combination is selected.

Next, step ST8 or step ST9
A change command is output from the arithmetic circuit 24 to the load connection circuit 19 in order to change the connection destination of the load 15 selected in (step ST10). Then, the load connection circuit 19 controls the double throw disconnector 18 based on the change command (step ST11).

Next, in the arithmetic circuit 24, the double throw disconnector 18
From the connection state of No. 2, it is determined whether the connection destination has been changed normally (step ST12, step ST13).
Finally, the display device 25 displays the connection state of the double throw disconnector 18 after a lapse of a certain time after the control (step ST
Along with 15), if the change is not normally performed, an alarm is displayed (step ST14), and the process ends.

Example 2. Further, in the above embodiment, the upper limit value and the lower limit value of the allowable value are explained as being equal, but the absolute values of the upper limit value (plus direction) and the lower limit value (minus direction) may be set differently. It has the same effect as the example.

[0024]

As described above, according to the first aspect of the present invention, it is determined whether or not the power flow value passing through the bus connecting line is within a pre-stored allowable value. For example, the adjusted power value is calculated from the difference between the power flow value and the allowable value so that the power flow value approaches zero, and the adjusted power value,
Since it is configured to select the load whose connection destination is changed based on the polarity of the power flow value, the power consumption value of each load, and the connection state of the double disconnector, and to change the connection destination of the selected load, The connection destination of the load is automatically changed according to the magnitude of the electric power flow value, and there is an effect that a highly stable power distribution system can be obtained.

According to the second aspect of the invention, the connection state of the load whose connection destination has been changed is displayed, and an alarm is displayed when the connection is not changed normally. The effect is that the load connection can be visually checked and a highly reliable power distribution system can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a power flow controller according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the power flow controller according to an embodiment of the present invention.

FIG. 3 is a system diagram showing a power distribution system.

[Explanation of symbols]

 1 Power Company 6 Power Receiving Bus 7 Private Power Generation Facility 9 Power Generating Bus 10 Bus Bus Connecting Line 15 Load 18 Double Throw Disconnector 19 Load Connection Circuit (Load Connection Means) 20 Input Circuit (Input Means) 21 Memory Circuit (Memory Means) 22 Connection Destination Change means 23 Confirmation means 25 Display device (display means)

Claims (2)

[Claims] 1. A load connection means for controlling a double disconnecting switch to connect a plurality of loads to either a power receiving bus supplied with electric power from an electric power company or a power generating bus supplied with electric power from a private power generation facility. , Input means for inputting a power flow value passing through a bus connecting line connecting the power receiving bus and the power generating bus and the power consumption value of each load and the connection state of the double-throw disconnecting switch, and the bus connecting line. Storage means for storing the allowable value of the passing power flow value, and whether or not the power flow value input by the input means is within the allowable value stored by the storage means, and it must be within the allowable value. For example, the adjusted power value is calculated from the difference between the power flow value and the allowable value so that the power flow value approaches zero, and the adjusted power value, the polarity of the power flow value, the power consumption value of each load, and the double throw Connection of disconnector A power flow control device comprising: a connection destination changing unit that selects a load whose connection destination is changed based on a state and outputs a change command to the load connecting unit. 2. A load connecting means for controlling a double disconnecting switch to connect a plurality of loads to either a power receiving bus supplied with electric power from an electric power company or a power generating bus supplied with electric power from a private power generation facility. , Input means for inputting a power flow value passing through a bus connecting line connecting the power receiving bus and the power generating bus and the power consumption value of each load and the connection state of the double-throw disconnecting switch, and the bus connecting line. Storage means for storing the allowable value of the passing power flow value, and whether or not the power flow value input by the input means is within the allowable value stored by the storage means, and it must be within the allowable value. For example, the adjusted power value is calculated from the difference between the power flow value and the allowable value so that the power flow value approaches zero, and the adjusted power value, the polarity of the power flow value, the power consumption value of each load, and the double throw Connection of disconnector Select the load to change the connection destination based on the connection state, and change the connection destination change means from the connection state of the connection destination change means that outputs a change command to the load connection means and the connection state of the double throw disconnector Power flow control with confirmation means for confirming whether or not it has been performed, and display means for displaying the result confirmed by the confirmation means and displaying an alarm when the connection change is not normally performed apparatus.