JPS6121516A - Fuel battery power generating system - Google Patents

Abstract

PURPOSE:To prevent stop of transmission due to a fault by storing an excess power generated at the fuel battery power generating system start and low load operation to a battery and discharging the battery at following to a load and a fault of battery thereby utilizing effectively a generated power. CONSTITUTION:When a load request signal is given, a controller drives a battery 2, a dummy load 3 or a DC/AC converter 8 in response to the power generating state of the fuel battery 1. In following the load, the battery 2 is applied at a time (t), the converter 8 applies phase control to decrease the transmission output and to decrease the battery output by controlling a hydrogen gas amount at the inlet of battery finally. During this time, the battery is charged. Then the similar operation is conducted even at a time t2, the battery 2 is discharged at a time t3. Thus, the lag in the leasing of the battery output is compensated and the load is followed quickly. The excess power is stored by providing the battery 2 and the battery is discharged in following the load, so as to utilize the generating power and prevent stop of transmission at a fault.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fuel cell and a fuel cell operation method in a DC/AC converter, and in particular, a method for storing surplus power generated during battery startup and low load operation, The present invention relates to a fuel cell power generation system that includes a storage battery between a battery and a DC/AC converter to enable smooth operation control by supplying power during load following or in the event of a battery failure.

[Background of the invention]

A conventional fuel cell power generation system (hereinafter referred to as Fe2) consisting of a fuel cell, a dummy load, and a DC/AC converter uses a dummy load to generate surplus power that is not related to the power transmission output during startup and low-load operation. '−
There was a drawback that the power utilization rate of FC8 decreased.

In addition, since the operation during load following was mainly performed by phase control of the DC/AC converter, there was a drawback that power loss was large.

Furthermore, there was a drawback that in the event of a battery failure, the power transmission of Fe2 had to be stopped.

[Purpose of the invention]

The purpose of the present invention is to store surplus power generated during FC8 startup and low-load operation in a storage battery, and discharge it in the event of load following or battery failure, thereby effectively utilizing battery-generated power and preventing power transmission outages due to accidents. The object of the present invention is to provide a fuel cell power generation system that is equipped with a control method that allows for control.

[Overview of the invention]

In Fig. 2, when the PCB is started, hydrogen gas is gradually introduced into the fuel cell from time 1o to start power generation, the fuel cell reaches the minimum output at time t1, and the output from the stain pond is increased from time t2. At the same time, power transmission is started and the rated output is reached at time 1 s.

In the conventional method, a dummy load is applied at time to, and surplus power generated by time t1 is consumed.

In Fig. 3, in order to prevent platinum in the battery catalyst from aggregating and deteriorating battery performance due to excessive voltage that occurs when the FC8C8 is operating at a low load and the battery is low output, at time t5, a dummy A load was applied, the battery output was set to the minimum output that would not cause excessive voltage, and the power transmission output was set to a low load output, and the difference in surplus power was consumed by a dummy load.

In the present invention, the surplus power generated in the above two cases is effectively used by charging a storage battery.

A method for effectively utilizing the electric power stored according to the present invention will be described below.

FIG. 4 shows the load following operation method according to the present invention when the load changes at time F + j2s "3.

If the load decreases at time tl, change the battery output to time (
1I, and the surplus power generated during that time is stored. Similarly, power is stored between times 12 and 121.

Next, when the load returns to the rated output at time t3', the storage battery is discharged to compensate for the difference due to the delay in starting up the battery output. In general, the output of a fuel cell can be easily reduced, but on the other hand, increasing the output requires a time delay of several seconds. D, FC8 The power transmission output and the load request output can be matched without causing any time delay.

In FIG. 5, time t! If battery power generation stops due to an accident or failure on the battery side, the storage battery is immediately discharged, the power necessary to maintain the operation of the facility equipment is supplied, and the battery power generation is stopped at time 1. When the fault is recovered, the battery will be activated again. In this way, in the event of an unexpected accident or breakdown, the operation of the FCS system can be maintained without receiving power supply from another source.

In FIG. 6, when the battery output drops instantaneously at time t1, the rated output can be maintained by discharging the storage battery.

In this way, by charging and discharging the storage battery provided between the fuel cell and the DC/AC converter, it is possible to smoothly track the cargo and maintain FC8 operation in the event of a hypothetical accident.

In the figure, 12 is a power transmission output, 13 is a power generation output, 14 is a charging area, and 15 is a discharging area.

[Embodiments of the invention]

The invention will be explained in detail with reference to FIG.

The fuel cell power generation system according to the present invention includes a fuel cell 1, a storage battery 2, a DC/AC converter 8, and a switch 4.

When the load request signal is given, the control device drives the storage battery 2, the dummy load 3, or the DC/AC converter according to the power generation state of the battery. In the case of load following shown in FIG. 4, time 1. At this point, the storage battery is turned on, and at the same time, the DC/AC converter performs phase control to lower the power transmission output, and finally, the battery output is lowered by controlling the amount of hydrogen gas at the battery inlet.

During this time, the storage battery is charged. A similar operation is performed at time t2, but if the required output on the load side is sufficiently low and the chargeable capacity of the storage battery is small, a dummy load can be applied to consume surplus power. Next, at time t3, the storage battery is discharged to compensate for the delay in rising the battery output and quickly follow the load.

Additionally, the storage battery can be used as a separate DC power source to supply power to other loads.

In the figure, 5 is a dummy load connection switch, 6 is a load connection switch, 7 is a DC breaker, 9 is a transformer, 10 is a compressor, and 11 is a valve.

〔Effect of the invention〕

With the fuel cell power generation system of the present invention, surplus power generated during startup and low-load operation can be effectively used during load following and during battery-side accidents.

[Brief explanation of the drawing]

Fig. 1 is a fuel cell power generation system diagram according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the starting method of the fuel cell power generation system, Fig. 3 is an explanatory diagram of the low load operation method, and Fig. 4 is an explanatory diagram of the low load operation method. Fig. 5 is an explanatory diagram of the fuel cell power generation system load following method according to the present invention, Fig. 5 is an explanatory diagram of the operating method in the event of a fuel cell accident according to the present invention, and Fig. 6 is an explanatory diagram of the operating method when the fuel cell instantaneous output decreases. FIG. 1...Fuel cell, 2...Storage battery, 3...Dummy load, 4...Storage battery connection switch, 5...Dummy load connection switch Fig. 2 f, (tb alignment%, r Fig.

Claims (1)

[Scope of Claims] 1. Fuel cell power generation consisting of a fuel cell and a DC/AC converter that takes fuel into the fuel electrode via a fuel reformer and takes oxygen into the oxygen electrode and generates electric power through a reaction between the two. In the system, a means for storing surplus power generated during startup and low-load operation of the fuel cell and supplying power during load following or in the event of an accident on the battery side, and means for also using it as a separate DC power source;
A fuel cell power generation system comprising a storage battery provided between the fuel cell main body and the DC/AC converter.