Multirotor UAV ESC，How to Choose？

As is well known, the Electronic Speed Controller (ESC) is one of the critical components of a multirotor drone, primarily responsible for regulating the speed and direction of the motors. Its working principle involves converting signals from the Flight Controller into precise power adjustments, ensuring smooth and stable flight. The correct selection of an ESC directly impacts the drone's efficiency, response speed, and lifespan.

Today, we will delve into the key factors of drone ESCs, including types, technical specifications, compatibility, and more, to understand how to choose the right ESC for multirotor drones.

1. Understanding the Role of ESCs in Multirotor Drones

An Electronic Speed Controller (ESC) is an electronic circuit that controls the speed of a motor by adjusting the current supplied from the battery. The primary roles of an ESC in a drone system include:

●  Controlling the speed and direction of the motors.

●  Regulating power efficiency to optimize output.

●  Providing smooth throttle response to prevent flight oscillations.

●  Supporting advanced flight functions like braking and telemetry, significantly enhancing drone performance and user experience.

In multirotor drones, each motor typically requires its own ESC, meaning a quadcopter needs four ESCs, while an octocopter requires eight.

2. Types of Drone ESCs

I. Standalone ESCs

●  Each motor is equipped with a separate ESC, mounted on the drone's arms.

●  Offers better heat dissipation, suitable for high-power drones.

●  Ideal for DIY assembly and professional-grade drones.

II. 4-in-1 ESCs

●  Integrates four ESCs onto a single circuit board.

●  Reduces wiring complexity and saves space.

●  Commonly used in FPV racing drones and lightweight drones.

III. Integrated ESCs

●  Directly integrated into the flight control board.

●  Suitable for micro drones and toy-grade drones, being lightweight and energy-efficient.

The choice of ESC type depends on your drone's application, size, and power requirements. For multirotor drones, standalone ESCs are often the most suitable.

3. Key Technical Specifications

I. Current Rating (A)

The current rating of an ESC determines the amount of current it can continuously handle. Common ratings include:

●  10A – 20A: Suitable for micro drones and indoor FPV racers.

●  30A – 40A: Suitable for medium-sized drones like aerial photography drones and FPV racers.

●  50A and above: Suitable for large drones like heavy-lift and industrial drones.

II. Voltage Rating (LiPo Compatibility)

Drone ESCs must be compatible with the drone's battery voltage. Most ESCs support 2S to 6S LiPo batteries, with some high-power ESCs supporting up to 12S.

III. Firmware

ESC firmware determines the motor's response characteristics. Common firmware includes:

● BLHeli-S: An upgrade of BLHeli, designed to support the DShot protocol, offering smoother motor control and faster response.

● BLHeli_32: Based on a 32-bit microcontroller, providing smoother power output and faster response.

● KISS ESC Firmware: Designed for high-performance and racing drones, offering precise control and ultra-low latency.

● SimonK: An early ESC firmware optimized for multirotor drones, offering quick response and simple configuration.

IV. Signal Protocols and Compatibility

ESCs communicate with the flight controller through various signal protocols. Faster signal speeds result in more precise motor responses:

● PWM (Pulse Width Modulation): Traditional, widely compatible, but slower response.

● OneShot: Faster than PWM, reducing signal delay.

DShot: A digital protocol offering higher precision and reliability.

V. BEC (Battery Eliminator Circuit)

Some ESCs include a BEC to power components like the flight controller. BECs can provide regulated power (usually 5V or 12V) to onboard electronics without a separate battery.

4. ESC Driving Schemes

I. Six-Step Commutation

●  Simple structure, easy to implement control algorithms, suitable for low-cost applications.

●  Higher efficiency at medium to low speeds.

II. Sine Wave Control

●  Low noise and vibration, suitable for high-precision applications.

●  Higher efficiency, especially at medium to high speeds.

III. FOC (Field Oriented Control)

●  Highest efficiency, optimizing current phase for better power output and endurance.

●  Precise control, suitable for complex conditions like high-speed and high-load scenarios.

5. How to Choose the Right ESC for Multirotor Drones

I. Choose Based on Drone Type

●  FPV Racing Drones: Lightweight, high refresh rate ESCs.

●  Aerial Photography Drones: High stability, precise control ESCs (30A-50A).

●  Heavy-Lift Drones: High current, high voltage support ESCs (50A-100A).

II. Match Battery, Motor, and ESC for Compatibility

●  Current rating should exceed the motor's maximum power consumption.

●  Voltage rating must be compatible with the battery.

III. Consider Heat Dissipation and Quality

●  High-quality MOSFETs improve efficiency and reduce heat.

●  Aluminum heat sinks can lower the temperature of high-power ESCs.

IV. Size and Weight

●  Ensure the ESC's size fits the drone's installation space.

●  Lightweight design helps improve overall drone performance.

V. Protection Features

●  Start-up protection, throttle signal loss protection, stall protection, current protection, overheat protection, and low voltage protection.

VI. Programming and Debugging

●  Programmability: Some ESCs allow parameter adjustments for performance optimization.

●  Debugging tools: Check for available tools or software for easy setup and adjustment.

VII. Brand and Quality

●  Choose reputable brands for better reliability and after-sales service.

VIII. Consider Future Upgrades

●  Current and voltage headroom: Choose ESCs with higher ratings for future upgrades.

●  Support for multiple signal protocols: Ensure compatibility with future components.

●  Good heat dissipation design: Effective cooling for higher power motors.

By understanding the working principles and selection criteria of ESCs, you can choose the best your Multirotor UAV ESC, enhancing flight performance and stability. If you have any questions during the selection process, feel free to consult LIGPOWER!