JPH01126137A - Power equipment using fuel cell - Google Patents

Abstract

PURPOSE:To prevent a power reverse flow surely without using a reverse power relay by rectifying and then connecting a received power in parallel with a fuel cell output and by supplying an inverter with said received power. CONSTITUTION:In a power consumption plant 1, a fuel cell 2 is provided as a main power supply and a power receiver 4 for receiving AC power supplied from a general electric power company 3 is provided as an auxiliary power supply. After the AC power of said power receiver 4 has been rectifier by a rectifier 7, said power is connected in parallel with the output of said fuel cell 2 to flow together. Then, said AC power is inputted to an inverter 8 to be converted into AC and thereafter supplied to a consumption side AC output end 6. Not only said rectifier 7 but also said fuel cell 2 have the function of preventing a power reverse flow. Therefore, even if outputs of both of them are connected in parallel, it is unnecessary to use a reverse power relay.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device using a fuel cell, in which a fuel cell and an AC power source are connected in parallel to a consumption side AC output terminal.

[Conventional technology]

Conventionally, when a fuel cell and an AC power source are connected in parallel to a consumption side AC output terminal, for example, even when an emergency storage battery and an AC power source are connected in parallel to a consumption side AC output terminal. Similar to installing an inverter in the power supply line from an emergency storage battery, from the viewpoint that the final output state is AC and the purpose is to obtain AC, the third
As shown in the figure, the DC power from the fuel cell (2) is converted to AC by the invanitor (12), and then the AC power source (4
) is combined with the AC power from the consuming side AC output terminal (6)
(See Tokyo Denki University Press, New Edition New Battery, p. 219).

[Problem that the invention seeks to solve]

However, in the case of an emergency storage battery, in an emergency when the power supply from the AC power supply becomes unavailable (power outage) for some reason, the power supply line to the consumption side AC output terminal is switched from the AC power supply side to the emergency storage battery side. Basically, the configuration is such that there is no situation in which both the emergency storage battery and the AC power source are connected to the AC output terminal on the consumption side at the same time, so power backflow from the emergency storage battery to the AC power source side occurs. There is no problem, but when connecting a fuel cell and an AC power supply in parallel to the AC output terminal on the consumption side, the purpose is to compensate for the lack of capacity of the fuel cell during peak power consumption by supplying power from the AC power supply. Because of this, there is a situation in which power is supplied from both the fuel cell and the AC power supply to the AC output terminal on the consumption side at the same time. It is necessary to prevent power from flowing backwards from the fuel cell to the AC power source side when power supply from the power source side becomes unavailable. It was necessary to install a reverse power relay (indicated by (13) in Figure 3) that automatically opens the power supply line from the AC power source based on the detection result.

However, since such reverse power relays are special equipment and are extremely expensive, there is a problem that the overall equipment cost of the power supply equipment is high.Also, since reverse power relays are automatic operating devices, there are concerns about operational problems. As a result, sufficient reliability has not yet been achieved in terms of safety, and the burden of inspection and management is also large.

An object of the present invention is to ensure safety against power backflow and to reduce costs through reasonable improvements.

[Means for solving problems]

The characteristics and configuration of the power supply device using fuel cells according to the present invention are as follows:
When the fuel cell and the AC power source are connected in parallel to the consumption side AC output terminal, a rectifier is provided to convert the AC power from the AC power source into DC, and the DC power from the fuel cell and the rectifier are connected in parallel. The present invention is provided with an inverter which converts the combined DC power into AC power and supplies the AC power to the consumption side AC output terminal, and its functions and effects are as follows.

[For production]

In other words, because a rectifier inherently prevents reverse energization from the DC output side to the AC input side due to its configuration, the AC power from the AC power source is converted to DC by the rectifier, and then the DC power from the fuel cell is converted to DC power. By merging with the AC power source, the rectifier will reliably prevent power from flowing backwards from the fuel cell to the AC power source.

Furthermore, since the rectifier is not an automatic operating device like a reverse power relay, there is no concern about operational trouble.

Note that fuel cells generate DC power through chemical reactions, and their structure inherently does not allow reverse flow of DC power. Therefore, the output DC power from the rectifier on the AC power supply side is transferred to the fuel cell side. There is no risk of backflow.

〔Effect of the invention〕

As a result, a power supply device that can reliably prevent power backflow and is highly reliable in terms of safety can be achieved.

In addition, since a reverse power relay, which is a special operating device, is not required and only a rectifier is required, the burden of inspection and management can be reduced, and the overall equipment cost of the power supply device can be reduced significantly. The practicality and versatility of a power supply device using fuel cells has been greatly improved.

〔Example〕

Next, an example will be described.

Figure 1 shows the power supply equipment in a power consumption base (1) such as a building or factory, with a fuel cell (2) installed as the main power source, and AC power supplied from a general electric power company (3) as a secondary power source. A power receiving device (4) is installed.

General gas companies (5) supply fuel to fuel cells (2).
The natural gas supplied from the fuel cell (2) is reformed with steam in the fuel cell (2), and the oxidizing agent is atmospheric air that is purified by a filter.

Furthermore, the exhaust heat from the fuel cell (2) is used for hot water supply, space heating, etc.

The fuel cell (2) and the power receiver (4), which is an AC power source, are connected in parallel to the AC output terminal (6) on the consumption side, and at peak power consumption, the insufficient capacity of the fuel cell (2) is used. This is supplemented by the power supply from the power receiver (4).

In other words, it is possible to install a fuel cell (2) that has enough capacity to cover the maximum power consumption during peak hours by itself, but in that case, the fuel cell (2) for most of the -
2) must be operated at a low load, which reduces the operating efficiency of the fuel cell (2), and also reduces the power generation efficiency of the fuel cell (2) due to the low load operation.

Therefore, as mentioned above, the fuel cell (2) and the general electric power company (3)
) is connected in parallel to the AC output terminal (6) on the consumption side, so that the power supply from the power receiver (4) makes up for the lack of capacity during peak hours. This allows the installed fuel cell (2) to have a capacity commensurate with the power consumption during normal power consumption, allowing the fuel cell (2) to operate under high load at all times. This is to increase the operating efficiency of the system and maintain its power generation efficiency at a high level, so that even if some power is purchased from the general electric power company (3) during peak hours, the overall cost is advantageous.

By connecting the fuel cell (2), which is a DC power source, and the power receiver (4), which is an AC power source, in parallel to the AC output terminal (6) on the consumption side, the AC power from the power receiver (4) is converted to DC. At the same time, the DC power from the fuel cell (2) and the DC power from the rectifier (7) are combined, converted into AC, and supplied to the consumption side AC output terminal (6). An inverter (8) is provided.

In other words, by converting the AC power from the power receiver (4) into DC power using the rectifier (7) and combining it with the DC power from the fuel cell (2), the rectifier (7) can also be used as a power backflow prevention device. -a From the power company (3) to the power receiver (
When there is a power outage in the power supply to the fuel cell (2)
) to the power receiver (4) side, and even -a electric power company (3)
The rectifier (7) prevents power from flowing backwards to the side.
This is to prevent troubles and accidents caused by such reverse current flow.

[Another example]

Next, another embodiment will be described.

As shown in FIG. 2, a voltage regulator (9) is connected to each of the power supply line from the fuel cell (2) and the power supply line from the rectifier (7) before the merging connection point.
(10), and with these constant voltage devices (9)
(10) By relatively adjusting the respective set voltages, it may be possible to appropriately adjust the load sharing for power consumption between the fuel cell (2) and the AC power source (4).

Further, as shown in FIG. 2, the consumption side DC output end (1) may be taken out.

The AC power source (4) is not limited to a power receiver that receives AC power supplied from a general electric power company, and may be a rotary generator or the like.

The type of fuel cell (2) is not limited, and any fuel and oxidizing agent may be used.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing another embodiment of the present invention. FIG. 3 is a configuration diagram showing a conventional example. (2)...Fuel cell, (4)...AC power supply, (6)...Consumption side AC output terminal, (7)...
... Rectifier, (8) ... Inverter.

Claims (1)

[Claims] A power supply device using a fuel cell, in which a fuel cell (2) and an AC power source (4) are connected in parallel to a consumption side AC output terminal (6), and the AC power source from the AC power source (4) is connected in parallel to the consumption side AC output terminal (6). A rectifier (7) for converting into DC is provided, and the DC power from the fuel cell (2) and the DC power from the rectifier (7) are combined and converted into AC to connect the consumption side AC output terminal (
6) A power supply device using a fuel cell equipped with an inverter (8).