Fuzzy State Machine Energy Management Strategy for Hybrid Electric UAVs with PV/Fuel Cell/Battery Power System

Table 4

Initial parameters of the hybrid power system.

Power source	Parameters	Values	Unit
Battery	Nominal voltage	22.2	V
	Rated capacity	6	Ah
	Fully charged voltage	25.2	V
	Cut-off voltage	21	V
	Internal resistance	0.04
	Capacity at nominal voltage	5.0	Ah
	Exponential zone	[23.5, 1]	[V, Ah]
	Initial state of charge	90	%
	Maximum charge power	200	W
Fuel cell	Voltage at 0A and 1A	[37, 33.7]	V
	Nominal operating point	[24, 25]	[A, V]
	Maximum operating point	[23, 28]	[A, V]
	Number of cells	41	—
	Nominal stack efficiency	43	%
	Operating temperature	50
	Nominal air flow rate	40	lpm
	Nominal supply pressure [fuel, air]	[0.55, 1]	bar
	Nominal composition [H2, O2, H2O (air)]	[99.95, 21, 1]	%
	Volume of H2 tank	0.5	L
	Purge water period	15	ms
	Maximum H2 flow rate when purging water	40	lpm
	Initial pressure in tank	200	bar
	Out of fuel pressure in tank	2	bar
Photovoltaics	Solar irradiance	1200	W/m^2
	PV panel area	0.5	m^2
	PV efficiency	0.3	—
	MPPT efficiency	0.98	—
Motor	Motor idle current	10	A at 10 V
	Rotation speed constant	420	rpm/V
	Motor internal resistance	33	mΩ
	Motor shaft rotational inertia	0.0001	kg·m^2
Propeller	Propeller diameter	0.254	m
	Propeller rotational inertia	0.002	kg·m^2
DCDC	Conversion efficiency	0.9	—
	Output voltage	25	V