Various embodiments may provide non-isolated single-input dual-output (SIDO) bi-directional buck-boost direct current (DC) to DC (DC-DC) converters. Various embodiments may provide a method for controlling a buck duty cycle of the non-isolated SIDO bi-directional buck-boost DC-DC converter such that a first voltage measured across a first portion of the non-isolated SIDO bi-directional buck-boost DC-DC converter is maintained at less than a voltage of a first load and a second voltage measured across a second portion of the non-isolated SIDO bi-directional buck-boost DC-DC converter is maintained at less than a voltage of a second load.

During startup of a fuel cell system, feed forward control is performed to increase the rotation number of an electric auxiliary device (compressor) to a modified steady state rotation number while maintaining a steady state rotation acceleration rate of the electric auxiliary device. In this manner, the overshoot amount is suppressed to an allowable overshoot amount. Otherwise, feed forward control is performed to increase the rotation number of the electric auxiliary device to a modified low steady state rotation number while maintaining a low steady state rotation acceleration rate. In this manner, the overshoot amount is suppressed to an allowable overshoot amount.

An operation mode of a secondary battery (BAT) is determined based on state of charge of BAT. A power generation provisional command value of fuel cell (FC) at time i is determined to maximize efficiency of FC based on system required power and state of charge of BAT at time i. An intermittent ON/OFF state at time i is determined such that switching of intermittent operation of FC is not continuous based on operation mode of BAT, the power generation provisional command value, and the system required power at time i, and an intermittent ON/OFF state at time (i−1). Further, when intermittent ON is determined at time i, the FC is stopped, and when intermittent OFF is determined at time i, a larger one is output, as the power generation command value for the FC at time i, between the power generation provisional command value and an intermittent OFF threshold.

A control system and a control method of fuel cell stacks are provided. The control system includes a set of fuel cell stacks, a secondary battery, a monitoring device, and a control device. Each fuel cell stack has a power output that can be independently started up or shut down. The secondary battery is connected to power output terminals of the fuel cell stacks via a power transmission path. The monitoring device is configured to monitor an electrical parameter of the power transmission path. The control device receives an electrical parameter signal from the monitoring device, and outputs a control signal to shut down or start up the power output of at least one of the fuel cell stacks if the electrical parameter's value is higher than a predetermined upper limit or lower than a predetermined lower limit.

An electric vehicle (EV) battery unit and installation method is provided herein. The EV battery unit includes a modular housing with a central section with batteries positioned therein and a first lateral section with a battery cooler that is designed to reduce a temperature of the batteries and an inverter that is positioned therein and electrically coupled to the batteries. The modular housing further includes a first frame attachment interface profiled to attach to a first longitudinal frame rail in an EV and a second frame attachment interface profiled to attach to a second longitudinal frame rail in the EV, where the batteries are positioned laterally between the first and second frame attachment interfaces.

Methods and systems are provided for cooling a hydrogen fuel cell assembly. A vehicle system, in one example, includes a hydrogen fuel cell assembly electrically coupled to a traction motor, positioned behind a cab, and including a plurality of hydrogen storage tanks and hydrogen fuel cells. The vehicle system further includes a fuel cell cooling assembly including an inlet manifold in a deflector, where the deflector is fixedly coupled to and positioned vertically above the cab and designed to direct airflow to a fan array that is coupled to a fuel cell assembly heat exchanger, where the fan array is positioned behind inlet manifold and longitudinally offset therefrom.

Methods and systems are provided for an electric vehicle powertrain. The vehicle system includes an electric distribution assembly with a junction box that is electrically coupled to a traction motor-generator and is designed to electrically coupled to, via separate circuits, a traction battery assembly and a hydrogen fuel cell assembly that is positioned behind a vehicle cab. In the system, the traction battery assembly is positioned vertically below the hydrogen fuel cell assembly.

A fuel cell system includes fuel cell, electrical storage device that stores electric power generated by the fuel cell, and control device of the fuel cell, the control device performs first control which causes the fuel cell to generate power and increases charging rate of the electrical storage device and second control which restricts output of the fuel cell to be smaller than that in the first control and decreases charging rate of the electrical storage device, and when switching condition, in which electric power demand from the external devices becomes greater than predetermined electric power or state in which electric power demand from the external devices is greater than the predetermined electric power continues for predetermined time, is satisfied, the control device increases power output by the fuel cell during the first control being performed to be larger than that before the switching condition was satisfied.

A method and a system for controlling startup of a fuel cell are provided. The method includes sensing a startup request signal and boosting a Bi-directional high-voltage DC/DC Converter (BHDC) of a main bus stage when the startup request signal has been sensed by a controller. A valve of an air/hydrogen line is then opened together with the boosting of the BHDC and the startup of the fuel cell is completed by allowing an output of the fuel cell after the valve of the air/hydrogen line is opened.

The electric power supply control apparatus for a vehicle executes a driving prioritizing mode in which a supply of driving electric power is prioritized over a supply of temperature controlling electric power, and a temperature control prioritizing mode in which the supply of the temperature controlling electric power is prioritized over the supply of the driving electric power. While the modes are switched over, the apparatus controls the driving electric power or the temperature controlling electric power so that a sum of the powers stays at an upper limit value or smaller.