JP2002252929A - Switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switching unit capable of enhancing the utilization facto of a generator by selecting a power supply which supplies electric power to loads in consideration of a power factor of an electric power load. SOLUTION: The switching device is equipped with a plurality of switching units 8A, 8B, etc., which are provided corresponding to a plurality of loads 6A, 6B, etc., respectively, and a switching controller 10 for performing switching control of a plurality of switching units. While the switching controller 10 conducts switching control of the plurality of switching units 8A, 8B, etc., based on an effective power and an apparent power of respective loads 6A, 6B, etc., and the plurality of switching units 8A, 8B, etc., which are switched to the side of the generator power supply 2 supplies an electric power from the generator power supply 2 to the loads 6A, 6B, etc., corresponding to the switching units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch for switching a power supply for supplying power to a load.

[0002]

2. Description of the Related Art For example, in a cogeneration system in which electric power from a generator power supply and electric power from a commercial power supply are switched as required and supplied to a load, a plurality of loads are connected to the generator power supply and the commercial power supply. Between them, a switch for switching the power supply is provided (see, for example,
1-1150871). The switching device includes a switching unit provided for each load, and a switching control device for switching and controlling these switching units. Each switching unit includes a pair of input units and one output unit, and a pair of switching units. It has a mechanical contact for selecting an input part, one input part is connected to the generator power supply, the other input part is connected to the commercial power supply, and the output part is connected to the corresponding load.

In such a switching unit, when a mechanical contact is electrically connected to, for example, one input portion, power from a generator power supply is supplied to a corresponding load via the mechanical contact, and Is operated by power from a generator power supply, and when a mechanical contact is electrically connected, for example, to the other input, power from a commercial power supply is supplied to the corresponding load via the mechanical contact. The load is operated by electric power from a commercial power supply. The switching control device performs switching control of each of the plurality of control units as described above, whereby the power source of the electric power supplied to each of these loads is switched and selected.

[0004]

In this type of conventional switch, the operating states of a plurality of loads are constantly monitored, and the current supplied to each load is measured. The switching control device uses the current value of each load to select an optimal combination of the plurality of loads such that the total power value approaches the power capacity of the generator power supply, and selects a switching unit corresponding to the selected load. Is switched to the generator power supply side, and the switching control is performed in this manner, whereby the utilization rate of the generator in the cogeneration system is constantly maintained at a state close to 100%, and the operating efficiency of the generator is increased.

However, this switch is applied to a single-phase load, and if it is applied to a three-phase load as it is, there are the following problems to be solved. In general, the power factor P
Is approximately 1 (P ≒ 1), and therefore, the active power and the apparent power are substantially equal. Therefore, even if the load selection by the switching control device is performed by using the current value of each load, there is substantially no problem. Absent. On the other hand, in the three-phase, the power factor must be considered, and if only the current value of each load is used to select a load, the utilization rate of the generator decreases and the operating efficiency of the generator decreases. The problem of lowering occurs. The active power capacity (also referred to as rated active power) of the generator power supply in a single-phase load is, for example, 9.8 KW, and the apparent power capacity (also referred to as rated apparent power) is, for example, 9.8 KVA. When applied to a phase load, the active power is determined based on the apparent power capacity. At this time, if the power factor P is, for example, 0.8 (P1 = 0.8), the active power value W of the load becomes Active power value (W) ≒ Rated apparent power value × Power factor Active power value (W) ≒ (9.8 × 0.8) = 8.3 KW, and the switching control device makes the active power value approach 8.3 KW. As a result, a combination of power loads is selected, and as a result, the generator is not operated with high efficiency, and the utilization factor is reduced.

In order to solve such inconvenience, for example, it is conceivable to select a power load so as to approach the apparent power capacity of the generator power supply. The active power of the power load may exceed the active power capacity of the generator power supply due to the power factor of the actual load. If the active power capacity exceeds the active power capacity of the generator power supply, the power generator may be damaged.

[0007] The above-mentioned problem occurs not only in the case of applying to a three-phase load but also in the case of applying to a single-phase load, when the power factor of the load is small. An object of the present invention is to provide a switch capable of selecting a power supply for supplying power to a load in consideration of the power factor of the load, thereby increasing the utilization rate of a generator power supply. It is another object of the present invention to provide a switch that can be conveniently applied to a three-phase load.

[0008]

According to the present invention, there are provided a plurality of switching units provided corresponding to a plurality of loads, respectively.
A switching control device for performing switching control of the plurality of switching units, wherein each of the plurality of switching units includes:
A switch for supplying power from a selected one of a commercial power supply and a generator power supply to a corresponding load, wherein the switching control device switches the plurality of switches based on active power and apparent power of each load. The switching control of the unit is characterized.

According to the present invention, the switching control device controls the switching of a plurality of switching units based on the active power and the apparent power of each load. Therefore, the switching control is performed in consideration of the power factor of the load. By comparing the active power capacity and the apparent power capacity of the generator power source, selecting a load for supplying power from the generator, and switching the switching unit corresponding to the selected load to the generator side, It becomes possible to operate the vehicle with a high utilization rate. Further, since a plurality of switching units are switched and controlled in consideration of the power factor, the switching unit is suitable for a three-phase load. Note that the active power and apparent power of each load can be obtained, for example, by measurement or calculation.

Further, according to the present invention, the switching control device includes:
Based on the active power and the apparent power of each load, the load is set such that the total active power value is smaller than the active power capacity of the generator power source and the total apparent power value is smaller than the apparent power capacity of the generator power. And controlling the switching of the plurality of switching units so that the power from the generator power supply is supplied to the selected load.

According to the present invention, the switching control device selects a load such that the total active power is smaller than the active power capacity of the generator power supply and the total apparent power is smaller than the apparent power capacity of the generator power supply. Then, since the switching unit corresponding to the selected load is switched so as to be on the generator side,
Power from the generator power supply is provided to the selected load.
Therefore, the active power and apparent power of the load to which the power from the generator power supply is supplied do not exceed the active power capacity and apparent power capacity of this generator power supply, and the cogeneration system, especially the generator power supply, is stabilized. Can be driven. Then, by bringing the total active power and the total apparent power close to the active power capacity and the apparent power capacity,
Operation with a high utilization rate of the generator power supply becomes possible.

Further, according to the present invention, the switching control device includes:
First, based on the active power of each load, the priority of the optimal combination of loads whose total active power value is close to a preset target active power value is selected, and then the priority order of the optimal combination is determined. Determining, based on the apparent power of each load, whether the summed apparent power value of the optimal combination is smaller than a preset target apparent power value, and when the summed apparent power value is smaller than the target apparent power value, A combination of loads is selected, and switching control of the plurality of switching units is performed so that power from the generator power supply is supplied to the selected load.

According to the present invention, the switching control device selects, based on the active power of each load, the priority of the optimum combination in which the total active power value is close to a preset target active power value. The target active power value is, for example, the active power capacity of the generator power supply, or 90 to 95% of the active power capacity.
The priority is set to a value of the degree, and the priority of the optimum combination is created, for example, in the form of a table. Next, the switching control device determines whether the total apparent power value of the optimal combination is smaller than a preset target apparent power value based on the apparent power of each load in the order of the priority of the optimal combination. And
When the total apparent power value is smaller than the target apparent power value,
The switching control device selects the load of the optimum combination, and controls the switching of the plurality of switching units so that the power from the generator power supply is supplied to the load of the selected combination. On the other hand, when the total apparent power value is larger than the target apparent power value, the switching control device has the total apparent power value smaller than the target apparent power value in the same manner as described above for the combination having the next highest rank of the optimal combination. Is determined. And
When the value is smaller, the combination is selected, and the plurality of switching units are switched as described above. On the other hand, when the value is larger, it is determined whether or not the combined apparent power value is smaller than the target apparent power value for the combination in the next rank of the optimal combination. . still,
This target apparent power value is set to, for example, the apparent power capacity of the generator power supply or a value of about 90 to 95% of the apparent power capacity. The switching control device determines whether the total apparent power value is smaller than the target apparent power value in the order of the priority of the optimal combination in this way, and selects the load of the reduced optimal combination. The active power and the apparent power of the load to which the power is supplied can be brought close to these capacities without exceeding the active power capacity and the apparent power capacity of the generator power supply, and the operation is performed with the utilization rate of the generator further increased. be able to.

Further, according to the present invention, the switching control device includes:
First, based on the apparent power of each load, the priority of the optimal combination of loads whose total apparent power value is close to the preset target apparent power value is selected, and then the priority order of the optimal combination is determined. Determining, based on the active power of each load, whether the total active power value of the optimal combination is smaller than a preset target active power value. When the total active power value is smaller than the target active power value, A combination of loads is selected, and switching control of the plurality of switching units is performed so that power from the generator power supply is supplied to the selected load.

According to the present invention, the switching control device selects, based on the apparent power of each load, the priority of the optimal combination in which the total apparent power value is close to a preset target active power value, The priority of the optimal combination is created in a table form, for example. Next, the switching control device determines whether the total active power value of the optimal combination is smaller than a preset target active power value based on the active power of each load in the order of the priority of the optimal combination. When the total active power value is smaller than the target active power value, the switching control device selects the load of the optimal combination, and selects a plurality of loads so that power from the generator power supply is supplied to the load of the selected combination. The switching unit is controlled to be switched. On the other hand, when the combined active power value is larger than the target active power value, the switching control device, for the next-ranked combination of the optimal combination, has the combined active power value smaller than the target active power value in the same manner as described above. Is determined. When the combination is smaller, the combination is selected, and the plurality of switching units are switched and controlled as described above. On the other hand, when the combination is larger, it is determined whether the combined active power value is smaller than the target active power value for the combination in the next rank of the optimal combination. judge. The switching control device determines whether the combined active power value is smaller than the target active power value in the order of the priority of the optimum combination in this way, and selects the load of the reduced optimum combination. The active power and the apparent power of the load to which the power is supplied can be brought close to these capacities without exceeding the active power capacity and the apparent power capacity of the generator power supply, and the operation is performed with the utilization rate of the generator further increased. be able to.

Further, in the present invention, each of the plurality of switching units includes an active / apparent power measuring device for measuring active power and apparent power of a corresponding load. According to the present invention, since each switching unit includes the active / apparent power measuring device, the active power and the apparent power of the load connected to each switching unit can be easily measured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a switch according to the present invention will be described below with reference to the accompanying drawings. Figure 1
1 is a block diagram schematically showing an example of a cogeneration system to which an embodiment of a switch according to the present invention is applied, and FIG. 2 is a block diagram schematically showing a switch control device of the switch in FIG. FIG. 3 is a flowchart showing the switching control operation of the switching device of FIG. 1, and FIG.
FIG. 5 is a diagram showing the contents of a table form of the priorities of the optimum combinations selected by the switches of FIG. 1, and FIG. 5 shows the generator power supply when the switch of FIG. 1 is used and when the conventional switch is used. It is a figure which shows a utilization rate.

In FIG. 1, the illustrated cogeneration system includes a cogeneration generator power supply 2 and a switch 4 for switching and supplying power to a plurality of loads, that is, loads 6A, 6B,. .. 8N, and a plurality of switching units 8A, 8B... 8N provided corresponding to the loads 6A, 6B. And a switching control device 10 for switching control. The cogeneration generator power supply 2 is composed of a generator driven by an engine such as a gas engine and a diesel engine. In the illustrated cogeneration system, an engine and a circuit for utilizing exhaust heat thereof are omitted. Further, the generator power supply 2 is not limited to the engine,
For example, a fuel cell or the like may be used.

A plurality of switching units 8A, 8B... 8
N have substantially the same configuration, and the configuration of one of these switching units 8A (8B ...) will be described. The switching unit 8A (8B...) Includes a power supply switching device 12 and a control unit 14 for controlling the power supply switching device 12. The power supply switching device 12 includes a pair of input units 1.
6, 18 and an output section 20 and a mechanical contact 22. One input section 16 is electrically connected to the cogeneration generator power supply 2 and the other input section 18 is connected to a commercial power supply 23, for example, an industrial three-phase power supply. It is electrically connected to a 200V power supply. The power supply switching device 1 in the switching unit 8A (8B...)
2 are electrically connected to corresponding loads 6A (6B...). The control unit 14 controls the switching of the mechanical contact 22 of the power supply switching device 12, and when the mechanical contact 22 is at the first position (for example, the state of the power supply switching device 12 of the switching unit 8C in FIG. 1), Are electrically connected to the input unit 16 and the output unit 20, and the power from the cogeneration generator power supply 2 is supplied to the load 6A (6B...). When the mechanical contact 22 is in the second position (for example, the state of the power supply switching device 12 of the switching unit 8A in FIG. 1), the other input section 18 and output section 20 are electrically connected, The electric power from the commercial power supply 2 is supplied to the load 6A (6
B ...). The loads 6A, 6B... 6
N is a device or a device that consumes power, such as a motor, a heating furnace, a lighting device, a ventilation fan, and an air conditioner.

The switching unit 8A (8B...)
Further, it includes a communication device 24 and an active / apparent power measuring device 26. The active / apparent power measuring device 26 is disposed between the power supply switching device 12 and the load 6A (6B ...), and measures the active power and the apparent power of the load 6A (6B ...). The communication device 24 includes a receiving unit that receives a signal, and a transmitting unit that transmits a signal. The receiving unit receives a signal from the switching control device 10, and the transmitting unit uses an active / apparent power measuring device 26A ( 26B) are sent to the switching control device 10.

Next, the switching control device 10 will be described with reference to FIG. 2 together with FIG.
0 denotes the switching controller 32, the operation unit 34, and the display unit 3
6 is provided. The switching controller 32 is composed of, for example, a microprocessor and includes a centralized control unit 38, an apparent power calculation unit 40, an active power calculation unit 42, a determination selection unit 44, and an instruction signal generation unit 46. In this embodiment, the active power calculating means 42 includes a plurality of loads 6
6N, that is, active powers measured by the active / apparent power measuring device 26, a total active power of various combinations of these loads 6A, 6B... 6N is calculated. , 6N based on the apparent power of the loads 6A, 6B,..., 6N, that is, the apparent power values measured by the active / apparent power measuring device 26. Of the above combinations are calculated. Further, the determination selecting means 44 determines whether or not the total apparent power value is smaller than a target apparent power value, which will be described later, and selects a combination when the total apparent power value is smaller than the target apparent power, as described later. The instruction signal generating means 46 generates an instruction signal for controlling the switching of the plurality of switching units 8A, 8B,... 8N as described later, and based on the instruction signals, these switching units 8A, 8B,. The switching of the 8N power supply switching device 12 is controlled. The centralized control unit 38 includes various components of the switching controller 32, that is, the active power calculation unit 42, the apparent power calculation unit 40, the determination selection unit 44, and the instruction signal generation unit 4.
6 and the like, and the priority of the optimum combination of loads is selected in the order in which the combined active power values of the various combinations calculated by the active power calculating means 42 become closer to the target active power value described later. The operation unit 34 includes various operation switches provided on an operation panel.
Operation of the entire cogeneration system, including
The display unit 36 is operated, for example, by a liquid crystal display device or the like, when the operation is completed, when various operation conditions, etc. are input, and the operation state of the cogeneration system, for example, each load 6
A, 6B... 6N, power supply state, these loads 6
A, 6B... 6N active power and apparent power are displayed.

The switching controller 32 further includes a first memory 48, a second memory 50, and a timer 52.
The first memory 48 stores a target active power value and a target apparent power value set in advance. The target active power value is set to, for example, the active power capacity (also referred to as rated active power) of the generator power supply 2 or a value of about 90 to 95% of this active power capacity. Assuming that the active power capacity of the generator power supply 2 is, for example, 9.8 kW, the target active power value is set to a value slightly smaller than the active power capacity, for example, about 9.3 kW. The target apparent power value is, for example, the generator power supply 2
Of the apparent power capacity (also referred to as rated apparent power) or 90 to 95% of this apparent power capacity. If the apparent power capacity of the generator power supply 2 is, for example, 12.3 kVA, the target apparent power is a value slightly smaller than the apparent power capacity.
For example, it is set to about 11.7 kVA. Second memory 5
In 0, the priority of the optimum combination of loads selected by the central control means 38 (described in detail later) is stored in, for example, a table format. The timer 52 is provided for each of the loads 6A, 6A.
B: Timing of measuring the 6N active power and apparent power is measured.

The switching control device 10 further includes a third memory 5
4 and a communication device 56. The communication device 56 includes a transmission unit and a reception unit, and the transmission unit transmits a transmission signal, for example, a measurement signal for instructing measurement of the active power and the apparent power to the communication devices 24 of the plurality of switching units 8A, 8B,. Transmitting and receiving means are provided by these switching units 8A,
The transmission signals from the communication devices 24 of 8B... 8N, for example, the active power signal and the apparent power signal are received, and the third memory 54 stores the data of the received active power signal and the apparent power signal.

Next, referring mainly to FIGS. 1 and 3,
The switching control operation of the switching device 4 will be described. First, the switch unit 4 is operated by inputting the operation unit 34 of the switching control device 10 (step S1). Next, one of the plurality of loads 6A, 6B,.
All loads) are started (step S2). At the time of this start, the power supply switching devices 12 of the switching units 8A, 8B,... 8N are held on the commercial power supply side (mechanical contacts 22).
Are electrically connected to the input section 18 connected to the commercial power supply 23). Therefore, each of the loads 6A, 6B,... afterwards,
The generator power supply 2 of the cogeneration system is activated (step S3), whereby power can be supplied from the generator power supply 2.

In such a state, each of the loads 6A, 6A
B ... The active power and apparent power of 6N are measured, and when the transmission timing for transmitting the measured data comes, the process proceeds to step S5 via step 4, and these active power signals and apparent power signals are converted into the respective switching units 8A and 8B. .. Transmitted from the 8N communication device 24 to the communication device 56 of the switching control device 10. In this embodiment, since the switching controller 32 of the switching control device 10 includes the timer 52, the transmission timing is performed using the timer 52.
When the timer 52 measures a predetermined time, for example, 300 seconds, and reaches the transmission timing, the instruction signal generating means 46
A measurement transmission signal is generated based on the signal from the second unit 2, and this measurement transmission signal is transmitted to each of the switching units 8A, 8B,. Thus, each switching unit 8A, 8B ...
8N, the active / apparent power measuring device 26 responds to the loads 6A, 6B
The active power and apparent power of 6N are measured, and the active power signal and the apparent power signal of the measured active power and apparent power are transmitted from the communication device 24 to the switching control device 10. In this manner, each of the loads 6A and 6B .. 6N active power and apparent power data at a predetermined timing
Sent to The transmission of the measurement transmission signal, the active power signal, the apparent power signal, and the like can be performed by, for example, wireless, wired, infrared, or the like. Then, the data of the active power and the apparent power transmitted to the switching control device 10 in this manner are stored in the third memory 54 (step S6).

In this embodiment, the switching control device 10
Although the data of the active power and the apparent power are transmitted based on the measurement transmission signal from, the following configuration may be used instead of such a configuration. That is, a timer is included in the control unit 14 of each of the switching units 8A, 8B,..., And a measurement transmission signal is generated by the control unit 14 of each switching unit using this timer. The data of the active power and the apparent power may be sent to the switching control device 10 based on

Thereafter, in step S7, the optimum combination rank of the load is selected. In this embodiment, the central control means 38 of the switching controller 32
A list of all combinations of A, 6B,.
The active power calculating means 42 uses the active power of each of the loads 6A, 6B,... 6N stored in the third memory 54 to calculate a total active power value for all of these combinations. Then, the central control means 38 selects, based on these combined active power values, those combinations in which the combined active power value is smaller than the target active power value, and selects the selected combinations in the target active power value. Are arranged in the order of values close to the load, and the order arranged in this way is the load 6A, 6B,.
The priority of the 6N optimal combination is given. In this embodiment, the central control means 38 creates the priorities of the optimum combinations in a table form as shown in FIG. 4, and the table of the priorities is stored in the second memory 50. In FIG. 4, in this table, the first, second,... And load combinations are arranged in the order of priority. For example, the first (second,.
The switching units marked with a circle in the combination of ()) are the switching units connected to the load selected in the combination. For example, in the first combination, the switching unit 8A (load 6A), the switching unit 8C (load 6C)
... The switching unit 8N (load 6N) is selected.

When the priority of the load combination is selected as described above, the first, that is, the highest priority combination is selected (step S8), and the apparent power of the load in the highest priority combination is determined. Is determined (step S9). In this embodiment, the apparent power calculation means 4
0 indicates each of the loads 6A and 6B stored in the third memory 54.
... By using the apparent power of 6N, the total apparent power value of the load of the highest priority combination is calculated,
Determines whether the sum apparent power value is smaller than the target apparent power value. If the total apparent power value is smaller than the target apparent power value, the process proceeds from step S10 to step S10.
Proceeding to 11, the determination selecting means 44 selects the highest priority combination.

On the other hand, if the total apparent power value is larger than the target apparent power value, a large power load may be applied to the generator power supply 2 with respect to the apparent power. The next combination in the order of priority, that is, the second combination is selected, and the process returns to step 9 where the apparent power calculation means 40 uses the apparent power of each of the loads 6A, 6B,. Then, the total apparent power value of the load of the second combination is calculated, and the determination selecting unit 44 determines whether the total apparent power value is smaller than the target apparent power value. If the sum apparent power value is smaller than the target apparent power value, the step S
Then, the process proceeds to step S11, where the determination selecting means 44 selects the second combination. On the other hand, when the total apparent power value is larger than the target apparent power value, the process returns to step S12, and the next combination in the order of the priority order, that is, The third combination is selected, and in the same manner as described above, the calculation of the total apparent power value is performed for the third combination and the comparison with the target apparent power value is performed. Then, in this way, it is determined whether the total apparent power value is smaller than the target apparent power value in the order of the priority of the optimal combination, and the load combination that is satisfied first is selected. Therefore, in the selected combination of loads, the combined active power value and the combined apparent power value of those loads are smaller than and close to the target active power value and the target apparent active power value.

When a combination of loads is selected as described above, the instruction signal generating means 46 sets the power supply switching device 12 of the switching unit 8 corresponding to the load 6 of the selected combination to the generator power supply 2 side. An instruction signal is generated (step S1).
3) The generated instruction signal is transmitted from the communication device 56 of the switching control device 10 to the communication devices 24 of the switching units 8A, 8B,. Thus, among the switching units 8A, 8B,... 8N, those corresponding to the combined load 6, the mechanical contact 22 is connected to the input unit 16 and the output unit on the generator power supply 2 side based on this instruction signal. 20 are electrically connected to each other, and power from the generator power supply 2 is supplied to the combined load 6. In the switching unit 8 corresponding to the remaining load 6, the mechanical contact 22 electrically connects the input unit 18 and the output unit 20 on the commercial power supply 23 side based on the instruction signal, and 6 is supplied with electric power from the commercial power supply 8 (step S1).
4).

Thereafter, the process proceeds to step S15, where the switching device 4
Until the operation is completed, the process returns to step S4, and the switching control of the switching units 8A, 8B... 8C is repeatedly performed in accordance with the above-described flow contents. In this embodiment, the switching control device 10 includes a plurality of switching units 8A, 8A based on the active power and the apparent power of each of the loads 6A, 6B,.
8N is switched as described above, so that the power supplied from the generator power supply 2 to the load is smaller than and close to the target active power value in the active power, and the apparent power is Is smaller than and close to the target apparent power value. Therefore, generator power supply 2
Is about 95% as shown by the solid line in FIG.
Efficient operation can be performed by constantly increasing the utilization rate of the generator power supply 2. For comparison with the utilization rate in this embodiment, the utilization rate of the generator by the conventional switching control is shown by a broken line in FIG. As can be easily understood from the above description in FIG. 5, the generator power supply 2 is operated by supplying power with a value close to the target active power value and the target apparent power value. The utilization rate of the generator power supply 2 can be adjusted by changing the apparent power value.

In the above-described embodiment, the priority of the optimal combination of loads is selected in the order of smaller and closer to the target active power value based on the combined active power value of the combined loads, and the combined load is determined in the order of the priority. The optimum combination of loads is selected by determining whether the total apparent power value is smaller than the target apparent power value. Instead, the target apparent power value is reduced based on the total apparent power value of the combined load. The priority of the optimum combination of the loads is selected in the order of the closest value, and it is determined whether the total active power value of the combined load is smaller than the target active power value in the order of the priority, and the optimum combination of the loads is selected. In substantially the same manner as described above, the utilization of the generator power supply 2 can be constantly increased by selecting the optimum combination of loads. In this case, the switching control device 10 replaces step S7 to step S12 in the flowchart shown in FIG. 3 with step S7A in the flowchart shown in FIG.
To select the optimum combination of loads along step S12A.

In FIG. 6, each switching unit 8A, 8B
, 8N, the active power and apparent power data of the corresponding loads 6A, 6B,... 6N are transmitted to the switching control device 10 and stored in the third memory 54.
6 to step S7A in FIG. Then, in step S7A, the optimum combination rank of the load is selected as follows. In this modified embodiment, the central control means 38 of the switching controller 32 includes a plurality of loads 6A,
6N, a list of all combinations 6B... 6N is prepared, and the apparent power calculation means 40 calculates the total apparent power value of all the combinations using the apparent powers of the loads 6A, 6B. I do. And the central control means 38
Based on these summed apparent power values, of all these combinations, the one whose summed apparent power value is smaller than the target apparent power value is selected, and the selected combinations are arranged in the order of a value close to the summed apparent power value, The order of the arrangement is the priority of the optimal combination of the loads 6A, 6B... 6N. Also in this modification, the centralized control means 38 creates the priority of the optimal combination in a table form as shown in FIG.
This priority order table is stored in the second memory 50.

When the priority of the load combination is selected as described above, the first, that is, the highest priority combination is selected (step S8A), and the active power of the load in the highest priority combination is determined. Is determined (step S9A). In this modification, the active power calculating means 42 uses the active power of each of the loads 6A, 6B,... 6N to calculate the total active power value of the load of the highest priority combination. Is smaller than the target active power value. When the total active power value is smaller than the target active power value, the process proceeds from step S10A to step S11A, and the determination selecting unit 44 selects the combination having the highest priority.

On the other hand, if the total active power value is larger than the target active power value, a large power load may be applied to the generator power supply 2 with respect to the active power. The next combination, that is, the second combination, is selected in the order of priority, and the process returns to step 9A.
As described above, the active power of each of the loads 6A, 6B,..., 6N is used to calculate the total active power of the loads of the second combination. Is determined to be smaller than the target active power value, and if it is smaller than the target active power value, the process proceeds to step S11A, where the determination selecting means 44 selects the second combination while the total active power value is equal to the target active power value. When it is larger than the power value, the process again goes to step S12A, and the next combination, that is, the third combination is selected in the order of the priority order, and the total active power value of the third The calculation is performed, and a comparison with the target active power value is performed. Then, in this way, it is determined whether the total active power value is smaller than the target active power value in the order of the priority of the optimum combination, and the load combination that is satisfied first is selected. Therefore, also in this modification, the combination of the selected loads is such that the total apparent power value and the total active power value of those loads are smaller than and close to the target active power value and the target apparent active power value. Thus, as understood from the above description, the generator power supply 2 can be operated at a high utilization rate.

While the embodiment of the switch according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention. is there.

[0037]

According to the switching device of the first aspect of the present invention, the switching control device switches and controls a plurality of switching units based on the active power and apparent power of each load. The control takes into account the power factor, selects the load that supplies power from the generator while comparing the active power capacity and apparent power capacity of the generator power supply, and generates the switching unit corresponding to the selected load. By switching to the generator side, it is possible to operate the generator at a high utilization rate.

According to the switch of the second aspect of the present invention, the combined active power is smaller than the active power capacity of the generator power supply, and the combined apparent power is smaller than the apparent power capacity of the generator power supply. Then, the switching controller selects the load,
Since the switching unit corresponding to the selected load is controlled to be switched to the generator side, the active power and the apparent power of the load to which the power from the generator power is supplied are determined by the active power capacity and the apparent power of the generator power. The cogeneration system, especially the generator, can be operated stably without exceeding the apparent power capacity.

According to the switching device of the third aspect of the present invention, the switching control device sets the total active power value to a value close to the preset target active power value based on the active power of each load. The priority of the optimal combination is selected, and then, in the order of the priority of the optimal combination, based on the apparent power of each load, is the total apparent power value of the optimal combination smaller than the target apparent power value set in advance? Therefore, the total active power value and the total apparent power value of the load to which the power from the generator power supply is supplied should be close to these capacities without exceeding the active power capacity and the apparent power capacity of this generator power supply. Therefore, it is possible to perform an operation in which the utilization rate of the generator power supply is further increased.

According to the switching device of the present invention, the switching control device first sets the total apparent power value to a value close to the preset target active power value based on the apparent power of each load. Then, based on the active power of each load, the total active power value of the optimal combination is higher than a preset target active power value based on the active power of each load. It is determined whether or not the total active power value and the total apparent power value of the load to which the power from the generator power supply is supplied do not exceed the active power capacity and the apparent power capacity of this generator power supply. The operation can be performed with the utilization rate of the generator power supply further increased. Further, according to the switching device of the present invention, since each switching unit includes the active / apparent power measuring device, the active power and the apparent power of the load connected to each switching unit can be easily measured. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing an example of a cogeneration system to which an embodiment of a switch according to the present invention is applied.

FIG. 2 is a block diagram schematically showing a switching control device of the switching device of FIG. 1;

FIG. 3 is a flowchart showing a switching control operation of the switching device of FIG. 1;

FIG. 4 is a diagram showing the contents of a table form of priorities of the optimum combinations selected by the switch of FIG. 1;

FIG. 5 is a diagram showing a utilization rate of a generator when the switch of FIG. 1 is used and when a conventional switch is used.

FIG. 6 is a flowchart showing a part of a switching control operation of a switching device according to a modified embodiment.

[Explanation of symbols]

 2 Cogeneration generator power supply 4 Switcher 6A, 6B... 6N Load 8A, 8B. 40 apparent power calculating means 42 active power calculating means 44 judgment selecting means 46 instruction signal generating means

Claims (5)

[Claims] A plurality of switching units provided for each of a plurality of loads; and a switching control device for controlling switching of the plurality of switching units, wherein the plurality of switching units are provided. Each of which is a switch that supplies power from a power source selected from a commercial power source and a generator power source to a corresponding load, wherein the switching control device performs the switching based on active power and apparent power of each load. A switching device for switching control of a plurality of switching units. 2. The switching control device according to claim 1, wherein a total active power value is smaller than an active power capacity of said generator power source based on an active power and an apparent power of each load, and said total apparent power value is said generator power. A load is selected so as to be smaller than an apparent power capacity, and the plurality of switching units are switch-controlled so that power from the generator power supply is supplied to the selected load. The switch according to 1. 3. The switching control device first selects, based on the active power of each load, a priority of an optimum combination of loads whose total active power value is close to a preset target active power value. Then, based on the apparent power of each load, it is determined whether or not the total apparent power value of the optimal combination is smaller than a preset target apparent power value based on the apparent power of each load. Selecting a load of the optimal combination when the target apparent power value is smaller than the target apparent power value, and controlling switching of the plurality of switching units so that power from the generator power supply is supplied to the selected load. The switch according to claim 2, wherein 4. The switching control device first selects, based on the apparent power of each load, a priority of an optimal combination of loads whose total apparent power value is close to a preset target apparent power value. Then, it is determined whether the total active power value of the optimal combination is smaller than a preset target active power value based on the active power of each load in the order of the priority of the optimal combination. Selecting a load of the optimal combination when the target active power value is smaller than the target active power value, and controlling switching of the plurality of switching units so that power from the generator power supply is supplied to the selected load. The switch according to claim 2, wherein 5. The apparatus according to claim 1, wherein each of said plurality of switching units includes an active / apparent power measuring device for measuring active power and apparent power of a corresponding load. The switch according to any one of the above.