CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-190877 filed on Oct. 18, 2019, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a fuel cell vehicle in which a fuel cell system is mounted, and to an activation method of a fuel cell vehicle.

Description of the Related Art

As disclosed in Japanese Laid-Open Patent Publication No. 2015-201407, a fuel cell system mounted in a fuel cell vehicle controls the power generation amount of a fuel cell stack based on a power generation demand or the like corresponding to the travel state of the fuel cell vehicle. Furthermore, the fuel cell system disclosed in Japanese Laid-Open Patent Publication No. 2015-201407 implements a current limiting process on the fuel cell when the power generation voltage of the fuel cell is lower than the voltage demanded by an external load, and then performs a process to increase the output current of the fuel cell to be less than or equal to an upper limit value.

SUMMARY OF THE INVENTION

In this type of fuel cell vehicle, when activating the fuel cell system in a state where the surrounding environment is at a low temperature (e.g. below the freezing point), warming up (standby power generation) is performed until the fuel cell stack reaches a temperature at which stable power generation is possible. During this warming up, travel manipulations by the user are not accepted, and therefore, if the standby power generation lasts a long time, the ease of use for the user decreases.

However, in order to prevent freezing inside the fuel cell stack in a case where low-temperature activation is expected, the fuel cell vehicle implements a scavenging process to reduce the moisture in the fuel cell stack. Therefore, even when the amount of reactant gas being supplied is rapidly increased and continues at the increased amount in order to shorten the standby power generation, the amount of moisture in the fuel cell stack is insufficient, and therefore the power generation of the fuel cell stack becomes unstable. Ultimately, the time-shortening of the standby power generation is insufficient, which can cause a worsening of the fuel efficiency.

The present invention has been devised taking into consideration the aforementioned problem, and has the object of providing a fuel cell vehicle and an activation method of the fuel cell vehicle, which make it possible to significantly shorten the standby time during activation while achieving power generation stability for a fuel cell system with a simple configuration.

In order to achieve the aforementioned object, a first aspect of the present invention is a fuel cell vehicle mounted with a fuel cell system including a fuel cell stack and a battery that is charged with power generated by the fuel cell stack, the fuel cell vehicle travelling using power of the fuel cell stack and the battery, and comprising a control section configured to, when a surrounding environment is at a low temperature, control operation of the fuel cell system prior to travelling, to perform standby power generation from activation to when travel is allowed and to perform power generation during operation of the fuel cell vehicle after travel has been allowed, wherein: during the power generation during operation, the control section increases a power generation current of the fuel cell stack in accordance with a first current increase rate; and during the standby power generation, the control section causes the battery to be charged with the power generated by the fuel cell stack and, when the power generation current of the fuel cell stack exceeds a standby switching current value set based on temperature information, the control section switches the first current increase rate to a second current increase rate that is a lower increase rate than the first current increase rate and increases the power generation current of the fuel cell stack in accordance with the second current increase rate.

In order to achieve the aforementioned object, a second aspect of the present invention is an activation method of a fuel cell vehicle mounted with a fuel cell system including a fuel cell stack and a battery that is charged with power generated by the fuel cell stack, the fuel cell vehicle travelling using power of the fuel cell stack and the battery, and being configured to, when a surrounding environment is at a low temperature, control operation of the fuel cell system with a control section prior to travelling, to perform standby power generation from activation to when travel is allowed and to perform power generation during operation of the fuel cell vehicle after travel has been allowed, the activation method comprising: during the power generation during operation, increasing a power generation current of the fuel cell stack in accordance with a first current increase rate; and during the standby power generation, charging the battery with the power generated by the fuel cell stack and, when the power generation current of the fuel cell stack exceeds a standby switching current value set based on temperature information, switching the first current increase rate to a second current increase rate that is a lower increase rate than the first current increase rate and increasing the power generation current of the fuel cell stack in accordance with the second current increase rate.

The fuel cell vehicle and the activation method of the fuel cell vehicle described above can significantly shorten the standby time during activation, while achieving power generation stability for the fuel cell system with a simple configuration.

The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which a preferred embodiment of the present invention is shown by way of illustrative example.

