JP2578480B2 - Power supply method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a power supply method, and particularly to an air-conditioning equipment, an electric motor,
The present invention relates to a power supply method suitable for supplying power to a lighting load or the like.

[Conventional technology]

In recent years, from the viewpoint of effective use of energy, a cogeneration system (cogeneration) capable of supplying both heat energy and electric energy has attracted attention (for example, September 30, 1986, Japan Cogeneration Research Group) Published, Cogeneration Vol.1, No.2, page 18, “C
VVF cogeneration ", page 26," VVVF cogeneration ", and JP-A-57-20579).

This combined heat and power supply system is a system that responds to heat demand such as hot water supply by using the waste heat of the drive source while driving a generator by a gas turbine, gas engine, etc. to generate electricity. If an appropriate combination of the above is possible, there is an advantage of improving energy efficiency and reducing costs.

[Problems to be solved by the invention]

However, in the power supply in such a conventional cogeneration system, only the “CVCF” mode or the “VVVF” mode is generated, and this power is supplied to all loads such as air conditioning equipment, electric motors, and lighting. For example, when the generated power is in the “CVCF” mode, the frequency is controlled in accordance with the increase or decrease in the flow rate for the equipment such as the air conditioning equipment, which increases or decreases the flow rate. Compared to the operation method (operation method in “VVVF” mode), there is a problem that very large amount of power is consumed. On the other hand, in the case of only “VVVF” mode, air conditioning equipment etc. Power supply, lighting,
It was difficult to supply power to loads requiring constant voltage and constant frequency, such as outlets.

Therefore, the present invention has been made in view of such problems of the prior art, and has been applied to a constant voltage / constant frequency power demand for lighting and the like and a variable voltage / variable frequency power demand for air conditioning equipment and the like. On the other hand, these demands can be met simultaneously by a single system, thereby saving energy, extending the life of the entire power generator, and stabilizing the power supply. It is an issue.

[Means for solving the problem]

In order to solve the above-mentioned problem, the present invention installs two power generation devices capable of selectively generating power in the “CVCF” mode and the “VVVF” mode for power generation devices having the same power generation capacity, and If one of the units is instructed to generate power in the "CVCF" mode, the other is instructed to generate power in the "VVVF" mode, and the power generation modes of both generators are switched to each other as necessary. The power generation / supply is adopted.

[Action]

According to the present invention, when one of the power generators supplies the power in the “CVCF” mode, the other power generator supplies the power in the “VVVF” mode, thereby supplying the power in both modes to the load. Can be done simultaneously. For this reason,
On the load side, a power supply that matches the characteristics of the load can be used. On the other hand, when the load amount of the specific load fluctuates due to the season or the like, when the power generation modes of the two power generators are switched to each other, this makes it possible to equalize the operation time of both the power generators. it can. As a result, the life of the entire equipment is prolonged, and stable power supply can be performed.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3 of the accompanying drawings. This embodiment is implemented for a cogeneration system.

In FIG. 1, 1A and 1B indicate two power generators. One of the first power generators 1A is an engine 2A that uses city gas or the like as a fuel, an AC generator 3A that is rotationally driven by the engine 2A, and a power generator that includes a control circuit unit of the generator 3A. And a machine panel 4A. Similarly, the other second power generator 1B includes an engine 2B, an AC generator 3B, and a generator board 4B.

Each of the generators 3A and 3B is a synchronous generator that generates power of “VVVF” characteristics. The generator panels 4A and 4B control the output of the generators 3A and 3B to clarify the relationship between frequency and voltage.
A control circuit is provided to obtain the output in the "F" mode and to control the exciting current to obtain the output in the "CVCF" mode. The generator panels 4A and 4B receive "CVCF" by the first and second switching command signals CS1 and CS2 output from the central command panel 5, respectively.
Switching circuits 6A and 6B for switching between the mode and "VVVF" mode
Is equipped. Therefore, the switching command signal CS1 or CS2
When the paths of the switching circuits 6A and 6B are switched to the “CVCF” side, the power generation state of the CVCF mode is established, and on the contrary, “VVVF”
When the mode is switched to, the power generation state of the VVVF mode is established, and power generation in each mode is performed. Also, the switching circuits 6A and 6B
It has an intermediate position to instruct power generation suspension.

The output sides of the generator boards 4A, 4B are individually connected to the input terminals of the changeover switches 7A, 7B of the changeover board 7. The changeover switches 7A and 7B have the same changeover position as the corresponding changeover circuits 6A and 6B, respectively, and switch in conjunction with the changeover circuits 6A and 6B by the same changeover command signals CS1 and CS2. I have. Then, the “CVCF” output terminals of the changeover switches 7A and 7B are connected to each other to reach a load (CVCF load) such as a lighting or an outlet which requires the “CVCF” mode, and to “VVV load”.
"F" output terminals are connected to each other, and loads (VVVF loads) such as heat source devices and heat medium transfer equipment that require "VVVF" mode
Has been reached.

Further, a commercial power supply is connected to the “CVCF” load via the on / off switch 9, and the system is interconnected.
This open / close switch 9 is an open / close command signal from the central command panel 5.
Opening / closing is controlled by SS. That is, the open / close switch 9 is opened (off) in a normal state, but is closed (on) when an abnormality or the like occurs, and power is supplied from the commercial power supply to the “CVCF” load in the “CVCF” mode. .

Here, the power generation capabilities of the first and second power generation devices 1A and 1B are set to be substantially the same.

On the other hand, the waste heat of the engines 1A and 1B is recovered by a waste heat recovery unit 10 such as an absorption chiller / heater, and this heat energy is supplied to an air conditioner or the like as a heat source.

 Next, the operation of this embodiment will be described with reference to FIGS.

First, a power supply method in a normal operation state will be described with reference to FIG. From the central command panel 5, switching control signals CS1, CS2 and an opening / closing command signal SS are output to each power generation system according to a manual operation or a preset program. That is, the second
As shown in FIG. 7A, when the power generation mode of the first power generation device 1A is set to the "CVCF" mode, the changeover switch 7A of the switchboard 7 is also switched to the "CVCF" end side in conjunction with this. In addition, the power generation mode of the second power generation device 1B side is the opposite mode “VVVF” mode.
Switches to the “VVVF” end. On the other hand, at this time, the open / close switch 9 on the commercial power supply side is opened (not shown) by the open / close control signal SS output from the central command panel 5.

For this reason, in the first power generation device 1A, power generation in the “CVCF” mode is performed, and this power is transmitted to the “CVCF” through the changeover switch 7A.
Supplied to the "CF" load. Along with this, the second power generator
In 1B, power generation in the “VVVF” mode is performed, and this power is supplied to the “VVVF” load via the changeover switch 7B.

The central control panel 5 reverses the switching control signals CS1 and CS2 based on a preset reference time (for example, one day change), as shown in FIG. 2 (b).
Switching is performed in a state opposite to the above-mentioned case in a state of being disconnected from the commercial power supply. That is, the first power generating device 1A generates power in the “VVVF” mode, and outputs the “VVVF” mode through the changeover switch 7A.
VF "load, and the second power generator 1B is" CVCF "
The power is generated in the mode, and this is supplied to the “CVCF” load via the changeover switch 7B.

Thus, according to the system of the present embodiment, first,
Since it has two power supplies of “CVCF” mode and “VVVF” mode, it can be used for loads (lighting, outlets, etc.) requiring constant voltage and constant frequency, Power can be simultaneously supplied to a load (heat source device, heat medium transfer device, etc.) that can be controlled in frequency. Therefore, as compared with the case of performing power generation / supply in either one mode as in the past, power can be efficiently supplied as a whole to various wide-ranging loads generally installed in building equipment, and energy saving can be achieved. Is achieved.

Secondly, the operation time of both power generators 1A and 1B is made uniform. In other words, in general, both modes of operation are performed during the cooling / heating period, but only the “CVCF” mode is operated during the interim period, and eventually the “CVCF” mode is operated year-round. Failure to do so results in operating time imbalance. However, in this embodiment, the operation is switched to the opposite mode at an appropriate timing, so that the operation times of the two are made uniform, and the life of the entire system is extended. This contributes to stable power supply.

Next, the maintenance and inspection of the power generators 1A and 1B and a power supply method at the time of failure will be described with reference to FIG.

First, it is assumed that the second power generator 1B temporarily stops operation due to maintenance or a failure. In this case, as shown in FIG. 3 (a), the second switching command signal CS2 causes the switching circuit 6B and the switch 7B of the second power generator 1B to be in the intermediate position to stop the power generation, and the first power generation is stopped. First by switching command signal CS1
The power generation device 1A generates power in the “VVVF” mode, and the on / off switch 9 is closed by the on / off command signal SS. As a result, power is supplied from the commercial power supply to the “CVCF” load, and at the same time, “VVVF” mode power is supplied from the first power generation device 1A to the “VVVF” load.

Further, when the first power generator 1A side is temporarily stopped due to maintenance inspection or failure, as shown in FIG. 3 (b),
Other than the closing of the open / close switch 9, a command is issued in the opposite direction to the above. As a result, electric power is supplied from the commercial power supply to the “CVCF” load and from the second power generator 1B side to the “VVVF” load.

As described above, in the present embodiment, since the “CVCF” system is interconnected with the commercial power supply, any of the power generation devices 1A or 1B
However, for example, even in the case of a failure, power can be supplied normally, and a stable supply system can be obtained simply by performing the mode switching control as described above.

In the above-described embodiment, the case where the power generation system in the “CVCF” mode is connected to the commercial power supply is described. However, in the present invention, in some cases, a system having a simple configuration may be used without performing this. Although the above-described embodiment has been described with reference to the case where the present invention is applied to a cogeneration system, the present invention is, of course, applicable to a mere power supply system. Further, each of the two power generation devices in the present invention,
The configuration may be such that the generators are operated in parallel depending on the power generation capacity of the generator.

By the way, the present invention is configured for both the “CVCF” mode and the “VVVF” mode. As an application example, for example, the “CVCF” mode and the “CVVF (constant voltage / variable frequency)” mode are similarly It can be configured, and can also be configured in three modes, a “CVCF” mode, a “VVVF” mode, and a “CVVF” mode.

〔The invention's effect〕

Since the present invention is configured and functions as described above, it can simultaneously respond to power demand of constant voltage and constant frequency for lighting and the like and variable voltage and variable frequency of air conditioning equipment and the like. As a result, it is possible to achieve an excellent effect that energy saving can be achieved as a whole of the power supply system and power supply can be stabilized.

In particular, in the power supply method according to the second aspect, in addition to the above-described effects, even if the power generator requires maintenance and inspection or a failure or the like occurs, the two modes can be operated without any trouble. Power supply and the fail-safe function can be expanded.

Furthermore, in the power supply method according to the third aspect, in addition to the effect according to the method according to the first aspect, the waste heat of the power generation device is recovered and used. Energy can be promoted.

Further, in the power supply method according to the fourth aspect, in addition to the effect according to the first aspect, there is an effect that the power generation capacity can be easily adapted to the magnitude of the load.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a cogeneration system according to an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are explanatory diagrams for explaining mode switching during normal operation, and FIG. 3 (a). )
(B) is an explanatory view explaining maintenance control and switching control at the time of failure, respectively. In the figure, 1A and 1B are first and second power generators, 2A and 2B are engines,
3A and 3B are generators, 4A and 4B are generator panels, 5 is a central control panel, 6
A and 6B are switching circuits, 7 is a switching board, 7A and 7B are switching switches,
Reference numeral 9 denotes an open / close switch, and reference numeral 10 denotes waste heat recovery means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirohito Matsuura 1-7-11 Nishigaoka, Uozumi-machi, Akashi-shi, Hyogo (72) Inventor Koichi Katayama 3-95 Chiyozaki, Nishi-ku, Osaka-shi, Osaka Special demand for Osaka Gas Co., Ltd. Within the Sales Department (72) Inventor Toshio Nagase 1000 Hamada, Amashiro-ku, Hyogo Prefecture Inside Nishiba Electric Co., Ltd. (72) Inventor Hisao Tanaka 2-4 Yotsuya, Shinjuku-ku, Tokyo Inside Shinryo Corporation (72) Inventor Hiroyuki Yamamoto 2-4 Yotsuya, Shinjuku-ku, Tokyo Inside Shinryo Corporation (56) References JP-A-63-35198 (JP, A)

Claims (4)

(57) [Claims] 1. A constant voltage / constant frequency mode (hereinafter referred to as "CVCF").
Mode) and variable voltage / variable frequency mode (hereinafter referred to as “VVVF” mode), two power generators of the same power generation capacity are installed. If one of them is instructed to generate power in the “CVCF” mode, the other is instructed to generate power in the “VVVF” mode, and the power generation modes of both power generators are switched to each other as necessary to generate power. A power supply method characterized by supplying. 2. The power supply method according to claim 1, wherein the power supply in the “CVCF” mode is system-connected to a commercial power supply. 3. The power supply method according to claim 1, wherein the power generation device is a power generation device constituting a cogeneration system. 4. The power supply method according to claim 1, wherein each of the two power generation devices is a power generation device that operates in parallel operation or independent operation of a generator.