UAV Power System Components

1- Motor Definition

A device that converts electrical energy into mechanical energy, comprising a stator, rotor, iron core, and magnetic steel. Types: There are two main types – brushed motors and brushless motors. Brushless motors are predominantly used in current drones. Standard Naming: Motors are typically labeled with four digits, where the first two digits represent the stator diameter, and the last two digits indicate the stator height. For example, a motor with the specification “4108” has a stator diameter of 41mm and a height of 8mm. KV Value: Represents the motor’s speed under unit voltage. Generally, a higher KV value indicates a faster motor speed. The product of the KV value and voltage (V) yields the motor’s idle speed measured in revolutions per minute (RPM).

2- ESC (Electronic Speed Controller)

Definition: An electronic device that supplies power to the motor and controls its speed. Operating Principle: The ESC receives and analyzes signals from the flight controller, converting direct current into specific pulsed alternating current to control motor speed.

Continuous Maximum Current: Commonly used ESCs have ratings of 60A, 80A, 100A, or even 120A. Main Control Types: ESCs are primarily classified as square wave and FOC (Field-Oriented Control).

3- Propeller

Definition: A device that transforms engine rotational power into thrust or lift. Parameters: Propellers are described by their diameter and pitch, with the diameter measured in inches and the pitch in millimeters. For instance, an “8045” propeller refers to one with an 8-inch diameter and a pitch of 45mm. Specification Naming: Propeller specifications consist of four numbers, where the first two signify the propeller diameter, and the last two indicate the pitch. Blade Number and Efficiency Relationship: Fewer blades generally result in higher efficiency. When comparing quadrotor and hexacopter UAVs with similar wheelbase, battery specifications, and identical take-off weight, quadrotors typically have longer flight times than hexacopters.

Also Read: Can the drone be powered by cables?

The battery used in drones is typically a high-rate lithium polymer battery, known for its high energy density, lightweight design, and strong current resistance. One common type of battery used in electric drones is the 18650 battery, which is often utilized in fixed-wing drones and small multi-rotor drones that operate at low voltages. The specification of drones often includes a number followed by “S,” which represents the number of batteries used. For example, 6S signifies six batteries, while 12S implies twelve batteries.

Additionally, a DC-DC converter from Current Logic can convert the high voltage of the drone’s battery pack to commonly used voltages such as 24V, 12V, or 5V for various electronic equipment. This allows for the design of battery packs or generators without the need to consider the specific voltage requirements of the equipment to be carried.