JPS60176426A - Load amount 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] [Technical Field of the Invention] The present invention provides a load amount control device for supplying electric power to a load group (two groups) consisting of a plurality of loads, for parallel operation of a plurality of different power supply systems. 42 related.

[Technical background of the invention and its melting point]

In recent years, in electric power systems, in order to ensure a highly reliable power supply to a load group, a power purchasing system and a private power generation system have been prepared as power supply systems, and these systems are operated in parallel. In this case, a demand monitoring device is installed in the power purchasing system to monitor and control the demand power so that it does not exceed the set value of the contracted power. In general, this type of demand monitoring and control device only monitors or controls the load on contract power, and for example, load shedding when the power supply side trips due to a failure in the purchasing side transformer (trip due to overcurrent, etc.) This was done through a separate load selection sequence, but there was no correlation between them.

If a trip occurred on the stain source side due to a failure of the tamashi transformer or private generator, the load under the system would be cut off, preventing secondary power outages within the system.

As a result, all loads under that system were cut off, and even if there was some margin from the perspective of the power demand system, the reduction in factory operating rates due to the above-mentioned accident was unavoidable.

[Purpose of the invention]

The purpose of the present invention is to maintain the limit load of the load group without uniformly cutting off the corresponding load group even when an accident occurs in the power supply system, thereby reducing the factory operating rate while preventing the accident from spreading. It is an object of the present invention to provide a load amount control device that can prevent this and can always maintain the optimum load amount within the contract power by linking with demand monitoring control.

[Summary of the invention]

The present invention relates to a load amount control device for supplying electric power to a load group consisting of a plurality of loads through parallel operation of a plurality of different power supply systems.

As shown in FIG. 2, there is a demand monitoring means for inputting the amount of electricity demanded from one of the plurality of power systems and comparing it with a set value, and a case where a trip occurs in one of the plurality of power systems. A means for determining which system is causing the trip, and calculating the limit load amount of the load group that was being supplied with power from the system that caused the trip when the trip occurred, and the capacity of the remaining power system for that load group. load amount determining means for determining a cut-off load amount or an input load amount for bringing the demanded power amount closer to the set value based on the comparison result with the demand monitoring bag when a trip has not occurred; means for determining a load to be cut off or a load to be turned on in order to satisfy the load amount determined by the load amount determining means; , to maintain the operating load at an optimal value.

[Embodiments of the invention]

The present invention will be described in detail below with reference to an embodiment shown in the drawings.

FIG. 1 shows the relationship between the device of the present invention and the power system that is the object to be controlled. In the figure, 1.2 is each transformer No. 1 and No. 2, and the primary side of the transformer is connected via the transformer primary breaker 3.4, and further connected to the power purchase system breaker 5, the same disconnector 6, and the transaction It is connected to a power transmission line (not shown) via a current transformer MOF. Note that the transaction power measurement device MOF includes a power meter W.
H is connected and generates a pulse every predetermined demand power.

On the other hand, reference numeral 7.8 denotes No. 1 and No. 2 private generators, the output ends of which are connected to bus bars 11 and 12 through generator circuit breakers 9 and 10, respectively.

In addition, the secondary sides of the No. 1 and No. 2 transformers 1.2 are transformer secondary circuit breakers 13 and 14, and interconnection circuit breakers 15 and 16.
and 17, 1.8, this is the bus disconnector 19
, 20 to the busbar 11, and the busbar disconnector 21,
22 to the bus bar 12, respectively. moreover,
The buses 11 and 12 are interconnected by a bus disconnector 24, and a first group of nine loads 26 is connected between each of the disconnectors 23 and 24 via a load group breaker 25.

Furthermore, second and third load groups 29 and 30 are connected between the transformer secondary circuit breakers 13 and 14 and the interconnection circuit breakers 15 and 16 via a load group circuit breaker 27 and a is connected. In the figure, 0. Darkness represents a closed state, and 01 mouth represents an open state.

Each of the load groups 26, 29, and 30 is composed of a plurality of loads.

Reference numeral 31 denotes a load selection cutoff device of the present invention, which inputs the measured value input (analog amount) A, status, fault input (digital amount) B, and required power amount (pulse) D from the power grid, and A cutoff output C is output to the grid. Here, the measurement value input persons are No. 1 and No. 2.
Input the output power of the No. 1 transformer 1.2, the generated power of the No. 2 private generator 7.8, and each load power, and also input the state and failure human power B as the breaker and disconnector equipment operation (open, (closed) status input and trip failure input (relay output). In addition, from each load group 26, 29, 30, only the breaker state signal of each load valve corresponding to the operating state of each load (not shown) is input.

Furthermore, the output pulse of the power meter WH is inputted as the power demand measurement.

FIG. 2 is a block diagram showing each function performed by the central information processing unit 3J as means. In the figure, 41 is a demand monitoring means that counts pulses from the electricity meter WH installed at the power receiving point shown in Fig. 1, and executes the operation shown in Fig. 3 at each preset monitoring synchronization. . That is, the demand power (received power) WR at that point is calculated from the pulse count value, and in step 4111, it is compared with the set value "contract power WK with the electric power company, and at the end of the demand, the demand power WR is the contracted power." It is determined whether or not the power WK is exceeded (step 412).As a result, if the power WK is not exceeded, the demand is set to normal (step 413).
), if the demand exceeds, set the demand over (step 414) L, and end.

Reference numeral 42 denotes a trip location determining means that detects a trip location in any one of the power supply systems in the power system shown in FIG. When a failure occurs and the corresponding circuit breaker trips, it is possible to determine which power supply system has tripped. That is, the status/failure signal A for each device is input from the power system side, and the central information processing unit 31 constantly scans this signal A.

Therefore, as shown in Fig. 4, when a trip occurs, a trip signal corresponding to the faulty equipment is detected (step 4).
2j). Then, the corresponding trip occurrence location i is determined from this trip signal. Step 422) ends.

Reference numeral 43 denotes a load determining means, to which demand information is given from the demand monitoring means 41, and trip originating place calculating information is given from the trip calculating means 42. Further, from the power system example, status signals and current power usage values for each device are input. This load amount determining means 43 executes the process at each preset control cycle, but when the above-mentioned trip occurs, the process is started regardless of the control cycle. Therefore, as shown in Figure 5,
First, determine whether this process is started due to a trip (
Step 431). As a result, if the activation is due to a trip, the assigned location (trip generation system)
According to i, a load group that is supplied with power from the trip generation system i is selected, and a limit load L1 is determined from the capacity of the remaining power supply system for this load group (step 432).
. For example, if a trip occurs in the power system including the transformer 1 in the power system shown in FIG. 1, the load group 29 that is supplied with power from that power system is selected. And this load group 29
This load group 2 is calculated from the capacity of the remaining power supply system that supplies power to
In step 9, the limit load iLi at which the operation can be continued is determined. Finally, the limit load amount Li is subtracted from the load capacity under operation at the time of trip to determine the cutoff load capacity.

On the other hand, if the activation is not based on the occurrence of a trip but is performed every normal control cycle, the demand information is determined (step 433). As a result, demand is normal (less than contract power)
If so, calculate how much more load can be operated without exceeding the contracted power, and determine the applied load capacity LoN (step 434). On the other hand, in the case of demand over, in order to keep the demand power within the contract power,
It calculates how much load needs to be stopped and determines the cut-off load condition LOFF (step 435).

Reference numeral 44 denotes input/cutoff target determining means for determining the load iLi or the amount determined by the load amount determining means 43. N.LOF
The load to be turned on or cut off is determined based on F and priorities etc. set for each load in advance.

This process is performed for each load group 26, 29, and 30. Therefore, as shown in FIG. 6, the counter j for each load group is cleared (step 441). Next, it is determined whether it is the j-th load group to be processed or the load group that has been supplied with power from the trip generation system (step 442). If this load group is a load group that has been supplied with power from the trip system, the limit load 1
A load whose capacity corresponds to the cutoff load capacity to be suppressed within HLi is determined as the load to be cut off (step 443
).

On the other hand, if the j-th load group is not the load group of the trip generation system, the limit power of that load group (also called block), the priority, and the input load it LoN
Alternatively, the input target or the shutoff target is determined according to the shutoff load amount LOFF (steps 444, 445, and 446).
). Here, a request mark is set for the devices determined to be turned on or cut off, with 1 device/1 bit. After these decisions are made, the counter j is incremented in step Q7), and it is determined whether the processing has been executed for all load groups.If it is the end of step 448L, step 44
Return to step 2, and if done, exit.

Reference numeral 45 denotes an on/off signal output means, which takes out the request bit set for each target device determined by the on/off target determining means 44 and outputs an on/off command to the corresponding device.

Here, regarding the above output, a trip occurs (because the two-way load shedding requires more speed).

As shown in FIG. 7, first, it is determined whether the load is cut off due to the occurrence of a trip (step 451). If it is due to the occurrence of a trip, the request bit is extracted (step 452), and a shutoff command is output to the corresponding device (step 453). After that, in order to process each load group, the load group counter j is cleared (step 454).
). Then, for the third load group, it is determined whether or not the load group was supplied with power from the trip generating system.Step 4
55) If the load group is unrelated to the occurrence of the trip, the request bit is extracted (step 456), and a turn-on or cut-off command is output to the relevant equipment (step 457). After the above output, increment the counter j in step 45.
8), it is determined whether processing has been completed for all load groups (step 459). If the result is the floor, step 4
Return to step 55, and if completed, end. Note that step 45
If it is determined in step 5 that the load group was receiving power from the trip generating system (N), this load group has been completely processed and the process jumps to step 455.

〔Effect of the invention〕

As described above, according to the present invention, when a trip occurs, the load is cut off by the amount necessary for online calculation, so that it is possible to prevent the spread of accidents and reduce the impact on the factory operating rate. Furthermore, since it is integrated with power demand control, even after a trip occurs, if there is equipment that can be operated in another block, it can be brought in, making it possible to improve the operating rate within the demand framework.

Furthermore, in normal times, the load is cut off and turned on by power control, which reduces the number of operations required by the operator, resulting in the effects of greater automation and labor savings.

[Brief explanation of drawings]

Figure 1 mainly shows the power system controlled by the present invention and 1-
2 is a block diagram showing an embodiment of the load amount control device according to the present invention, and FIGS. 3, 4, 5, 6, and 7 are details of the present invention. This is a flowchart explaining the process. 4J - Demand monitoring means, 42 Trip location determining means, 43... Valve load determining means, 44... Turning on/shutoff target deciding means, (7317) Agent: Kensuke Chika, patent attorney (and 1 more)
Figure 1 Figure 3 Figure 4 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] For parallel operation of a plurality of power supply systems that are different from each other, in a load amount control device when supplying power to a load group consisting of a plurality of loads, the amount of power demanded by one of the plurality of power supply systems is inputted. demand monitoring means for comparing this with a set value; trip location determining means for determining which system the trip occurred in when a trip occurs in any of the plurality of power systems; The limit load amount of the load group that was supplied with power from the trip generation system is determined based on the remaining power supply system response capacity for that load group, and if no trip has occurred, the limit load amount is determined based on the comparison result of the demand monitoring device. Load amount determining means for determining a cutoff load amount or input load amount to bring the demand power amount close to the set value, and a load to be cut off or input load to satisfy the load lid determined by the load amount determination means. A load amount control device comprising means for determining a load.