Embedded Systems and Design & Development - Feb 20, 2026 | Afternoon | VisionAstraa EV Academy

Understanding Motor Load and Performance

Introduction to Motor Components

• The discussion begins with an overview of essential components such as the main MCB, ignition switch, and key for starting the motor.

• A component is introduced that helps in adjusting the load on the motor from zero to 100%, allowing for a practical demonstration of how load affects performance.

Load Impact on Motor Performance

• The speaker explains how applying different loads (zero, 50%, and 100%) impacts current, voltage, and speed of the motor.

• At 50% load, the speed reaches approximately 61 km/h with a DC current reading of about 23.97 amps; this indicates an increase in current draw as load increases.

Observations at Full Load

• When increasing to a full load (100%), there is a noticeable spike in both current and speed; current can exceed 18 amps under maximum load conditions.

• The speaker emphasizes that while voltage remains stable, significant variations in current are observed as loads change.

Fault Conditions in Electric Vehicles

Types of Fault Conditions

• Discussion shifts to potential fault conditions in electric vehicles (EV), including ignition failure and emergency braking issues.

• An explanation is provided regarding how these faults affect power supply; if ignition fails, acceleration will not function due to loss of supply between pedal input and main power.

Emergency Systems Overview

• The conversation transitions into emergency systems like stop buttons and their importance during critical failures.

Communication Systems within EV Components

Communication Between Control Units

• The roles of VCU (Vehicle Control Unit), ECU (Electronic Control Unit), and MCU (Motor Control Unit) are discussed concerning communication needs for effective vehicle operation.

Wiring for Communication

• A two-wire twisted pair system is mentioned as crucial for communication among various EV components like ECUs and VCUs.

Three-phase Inverter Functionality

Conversion Process Explained

• Explanation on how three-phase currents are derived from a three-phase inverter which converts DC voltage into usable AC for motors.

Clark Transformation Insight

• Introduction to Clark transformation as part of Field-Oriented Control (FOC); it’s used to manage motor control effectively by converting three-phase currents into manageable forms.

Three-Phase Inverter and Control Techniques

Overview of Three-Phase Inverter Operation

• The discussion begins with the operation of a three-phase inverter, where three currents (IU, IV, IW) are taken as inputs.

• These currents undergo a CL transformation to convert them into two-phase parameters (Iα and Iβ), simplifying the analysis.

Transformation Process

• The conversion from two-phase to direct axis (D) and quadrature axis (Q) is explained; these axes represent independent current components in motor control.

• A PI controller is employed to set ID (direct axis current) to zero, optimizing efficiency by minimizing losses.

Control Mechanism

• The IQ value is processed further through PWM generation, converting it back into alpha and beta voltages before being sent to the inverter for motor operation.

• Emphasis on understanding the Field Oriented Control (FOC) method as crucial for effective motor control.

Detailed Explanation of Transformations

• A reiteration of the transformation process: starting from three-phase currents to two-phase using CL transformation, then moving to D and Q axes via Park transformation.

• Clarification that setting ID to zero allows only torque-producing components in the system.

Final Output Generation

• After processing through various transformations including inverse Clark and Park transformations, three-phase voltages (VAB and VC) are generated for driving the BLDC motor.

Battery Management System Setup

Introduction to BMS Technology Kit

• Transitioning from inverter discussion, a Battery Management System (BMS) setup is introduced with connected cells arranged in series.

Cell Configuration Details

• Eight lithium-ion cells are used in series; participants are encouraged to count them for clarity on configuration.

Internal Resistance Testing

• An internal resistance tester is presented as part of the setup; it measures how well each cell performs under load conditions.

Voltage Specifications

• Discussion on nominal voltage reveals that while full charge voltage may be 3.7V, nominal voltage per lithium cell is actually 3.2V.

Total Voltage Calculation

• Participants calculate total output voltage based on eight cells connected in series; expected reading should reflect cumulative nominal voltages.

Battery Voltage Measurement and BMS Technology

Connecting Cells and Measuring Voltage

• The first cell shows a voltage of 3.7V, indicating it is fully charged.

• As the second cell is connected, the voltage increases to 6.6V, then to 9.7V for the third cell.

• The fourth cell measures at 13.5V, while the fifth reaches 16.3V; the sixth cell shows 19.1V.

• The seventh cell's connection results in a total voltage of 25.4V, aligning closely with the DC meter reading of 25.3V.

Smart BMS Technology Overview

• Introduction of smart Battery Management System (BMS) technology that monitors total voltage across cells.

• Active balancer connections allow real-time monitoring of battery pack voltage and current values.

Components Demonstration

• A setup is shown where individual cell voltages can be calculated using specific components.

• Discussion on various components used in real-time applications, including temperature sensors and voltage indicators.

Battery Pack Structure

• Explanation of motor control units (MCUs), Vehicle Control Units (VCUs), and their relevance in electric vehicles like Ola.

• Description of an Ola battery pack structure featuring cylindrical lithium-ion cells interconnected with thin sheets.

Motor Control Unit Insights

• Overview of a motor control unit designed for Permanent Magnet Synchronous Motors (PMSM), highlighting its three-phase wiring system.

• Discussion on communication links between battery supply and motor controllers via CAN communication protocols.

DCDC Converter and EV Charging Overview

Understanding DCDC Conversion

• The discussion begins with an introduction to a DCDC converter that transforms 36V and 72V inputs into a 12V output, highlighting its function in voltage conversion.

• Participants are prompted to identify the type of conversion occurring, leading to the conclusion that it is a buck converter, which steps down voltage effectively.

Home EV Charging Solutions

• The speaker mentions a specific charger used for home applications, particularly for electric vehicle (EV) charging, noting that it takes longer than public chargers due to AC to DC conversion processes.

• A brief overview of the session's objectives is provided, indicating an intention to explain how components are connected within vehicles.

Vehicle Battery Configuration

• The conversation shifts to a specific EV model (BNM 1200), detailing its dual battery pack setup—one located at the rear and another at the front—emphasizing swappable technology.

Motor Controller and Hub Motor Insights

• An explanation of the motor controller's placement within the vehicle is given, along with details about three-phase power transfer to the hub motor connected directly to the wheel.

• The speaker notes that using a battery pack exceeding 60 volts allows operation of this assembled vehicle model (Ather 450), concluding with hopes that attendees found the session informative.