VECU vs ECU

ECU

ECU and VECU stand for:

• ECU: Electronic Control Unit  
• VECU: Vehicle Control Unit

While both are electronic control units within a vehicle, they serve different purposes and are found in different types of vehicles.  

ECU (Electronic Control Unit)

• Function: An ECU is a generic term for any electronic control unit in a vehicle. It can control various systems like the engine (engine control unit), transmission (transmission control unit), brakes (anti-lock braking system control unit), airbags, and more. In traditional gasoline or diesel vehicles, the primary ECU is often the engine control unit, which manages engine performance.  

• Vehicle Type: Found in conventional fuel vehicles (gasoline, diesel).  

• Focus: Primarily focuses on managing the specific system it is designed for, such as optimizing engine performance for fuel efficiency and emissions.  

VECU (Vehicle Control Unit)

VECU



• Function: The VECU is the central control unit in electric vehicles (EVs) and some hybrid vehicles. It manages the overall operation of the electric powertrain, including the battery, electric motors, regenerative braking, and other EV-specific systems. It also coordinates with other ECUs in the vehicle.  

• Vehicle Type: Found in electric vehicles (EVs) and some hybrid vehicles.  

• Focus: Manages the overall energy flow and efficiency of the electric powertrain, maximizing range and performance. It handles functions like regenerative braking, battery management, and coordinating the electric motors.  

Key Differences:

Below is a table summarizing the key differences:

Feature	ECU	VECU
Vehicle Type	Conventional fuel vehicles	Electric and hybrid vehicles
Primary Function	Manages a specific system (e.g., engine)	Manages the electric powertrain and overall vehicle operation
Energy Focus	Emissions and fuel efficiency	Energy efficiency and range
Key Functions	Engine control, transmission control, etc.	Battery management, regenerative braking, motor control

What is VECU in Electric Vehicles?

 

VECU of an Electric Vehicle

The VECU is a complex technology, and it's important to understand its functions thoroughly. 

1. Power Flow Management: (Energy Management)

• Battery to Motor: When accelerating, the VECU receives the signal from the accelerator pedal. It then determines the optimal amount of power to draw from the battery and deliver to the motor controllers. This involves complex calculations considering factors like:
  • Desired acceleration
  • Battery state of charge and temperature
  • Motor temperature and efficiency
  • Driving mode (e.g., Eco, Sport)
   
• Motor to Battery (Regenerative Braking): During deceleration or braking, the VECU reverses the motor's function, turning it into a generator.

    It controls the amount of regenerative braking to:

1. Maximize energy recovery.
2. Provide smooth and stable deceleration.
3. Prevent overcharging the battery.

Coordination with Other Systems: The VECU also communicates with other ECUs in the vehicle, such as the Battery Management System (BMS) and the Motor Control Unit (MCU), to ensure seamless power flow and prevent conflicts.

2. System Monitoring and Control:  (Performance and Safety)

• Battery Management: The VECU works closely with the BMS to monitor:
  • Individual cell voltages and temperatures.
  • Overall battery state of charge and health.
  • Cooling system performance.
  • It uses this information to optimize charging and discharging rates, prevent damage to the battery, and estimate the remaining range.
• Motor Control: The VECU monitors the motor's:
• Temperature.
• Speed and torque.
• Efficiency.
• It adjusts the motor's operation to maintain optimal performance and prevent overheating.   

• Thermal Management: The VECU plays a key role in managing the thermal systems of the EV, including:
  • Battery cooling and heating.
  • Motor cooling.
  • Cabin climate control.
  • It optimizes the operation of these systems to ensure efficient operation and passenger comfort.

3. Regenerative Braking: (Maximizing Efficiency)

• Blending with Friction Brakes: The VECU seamlessly blends regenerative braking with traditional friction brakes to provide consistent and effective stopping power.
• Optimizing Energy Recovery: It dynamically adjusts the amount of regenerative braking based on driving conditions, such as:
  • Speed
  • Road grade
  • Traffic
  • This maximizes energy recovery and improves overall efficiency.

4. Safety and Diagnostics: (Ensuring Reliability)

• Fault Detection and Management: The VECU constantly monitors all systems for faults and anomalies. If a problem is detected, 

          It takes appropriate action, such as:

• Triggering warning lights on the dashboard
• Limiting vehicle performance
• Storing diagnostic trouble codes (DTCs) for later analysis

 Functional Safety: The VECU is designed with safety in mind, adhering to strict functional safety standards (e.g., ISO 26262). This ensures that the vehicle operates safely even in the event of a component failure.

In summary, the VECU is a sophisticated and essential component in modern EVs. It acts as the central intelligence, managing power flow, monitoring systems, optimizing efficiency, and ensuring safety. Its complex algorithms and real-time control capabilities are crucial for delivering the performance, range, and reliability that EV owners expect.

DFMEA Process in Lithium ion battery?

DFMEA Cycle

DFMEA is a structured approach to identifying and assessing potential failure modes in a product or process design. 

By proactively identifying and addressing these potential failures, organizations can improve product reliability, reduce costs, and enhance customer satisfaction.

Key Steps in a DFMEA:

1. Define the System: Clearly outline the system or product being analyzed, including its functions and intended use.
2. Identify Function: List the primary functions of the system or product.
3. Identify Potential Failure Modes: For each function, brainstorm potential ways in which it could fail.
4. Identify Potential Effects: Determine the consequences of each failure mode on the system or product and the customer.
5. Assess Severity: Assign a severity rating to each potential effect, indicating the seriousness of its impact.
6. Identify Potential Causes: For each failure mode, identify the root causes that could lead to its occurrence.
7. Assess Occurrence: Assign an occurrence rating to each potential cause, indicating the likelihood of it happening.
8. Assess Detection: Determine the likelihood of detecting each failure mode before it reaches the customer. Assign a detection rating.
9. Calculate Risk Priority Number (RPN): Multiply the severity, occurrence, and detection ratings to obtain the RPN. A higher RPN indicates a higher risk.
10. Develop Action Plans: Prioritize the highest-risk failure modes and develop action plans to mitigate or eliminate them.
11. Implement Corrective Actions: Execute the action plans to address the identified risks.
12. Re-evaluate: Periodically review the DFMEA to identify new risks and update the analysis as necessary.

Benefits of DFMEA:

• Proactive Risk Management: Identifies potential failures early in the design phase.
• Improved Product Quality: Reduces the likelihood of product failures and defects.
• Enhanced Customer Satisfaction: Delivers more reliable and durable products.
• Cost Reduction: Prevents costly recalls and field repairs.
• Regulatory Compliance: Helps meet industry standards and regulatory requirements.
• Continuous Improvement: Fosters a culture of continuous improvement and risk mitigation.

By systematically applying DFMEA, organizations can significantly improve their products and processes quality and reliability.

Lithium-ion battery DFMEA Analysis (Design Failure Mode and Effects Analysis)

Here's how the DFMEA process is applied to lithium-ion batteries:

1. Define the Scope:

• Clearly define the system or subsystem being analyzed (e.g., the entire battery pack, a single cell, the battery management system (BMS), etc.).
• Identify the functions and requirements of the system.

2. Identify Potential Failure Modes:

• List all potential ways in which the battery or its components could potentially fail. Examples include:
  • Cell Level: Internal short circuit, electrolyte leakage, thermal runaway, capacity fade, overcharge, over-discharge.
  • Pack Level: Poor thermal management, inadequate electrical connections, BMS failure, mechanical damage.
  • Material Level: Degradation of electrodes, separator breakdown, current collector corrosion.

3. Determine the Effects of Each Failure Mode:

• Describe the consequences of each failure mode on the battery's performance, safety, and reliability. Examples include:
  • Reduced capacity, loss of power, overheating, fire, explosion, shortened lifespan.

4. Assign Severity Ratings:

• Assign a numerical rating (typically on a scale of 1 to 10) to each failure mode based on the severity of its effects. A higher rating indicates a more severe consequence. 

5. Identify Potential Causes of Each Failure Mode:

• List all the possible causes that could lead to each failure mode. Examples include:
  • Manufacturing defects, material impurities, improper handling, extreme temperatures, mechanical stress, and electrical abuse (overcharge/over-discharge).

6. Assign Occurrence Ratings:

• Assign a numerical rating (typically on a scale of 1 to 10) to each cause based on the likelihood of it occurring. A higher rating indicates a higher probability of occurrence. 

7. Identify Prevention Controls:

• Describe any existing design features or controls that are in place to prevent or detect the failure modes. Examples include:
  • Safety vents, thermal fuses, BMS functions (overcharge/over-discharge protection, temperature monitoring), and quality control measures.

8. Assign Detection Ratings:

• Assign a numerical rating (typically on a scale of 1 to 10) to each control based on its ability to detect the failure mode before it has a significant effect. A higher rating indicates a lower probability of detection.

9. Calculate the Risk Priority Number (RPN):

• For each failure mode, calculate the RPN by multiplying the severity, occurrence, and detection ratings:
  • RPN = Severity x Occurrence x Detection
   
• The RPN provides a quantitative measure of the risk associated with each failure mode.

10. Develop Recommended Actions:

• For failure modes with high RPNs, develop and implement corrective actions to reduce the risk. These actions may include:
  • Design changes, material selection, process improvements, and additional controls.
     

11. Take Action and Re-evaluate:

• Implement the recommended actions and then re-evaluate the RPNs to ensure that the risk has been adequately reduced.

Lithium Batteries Failure Cause and Effects:

                                                             Lithium-ion battery DFMEA Analysis (Design Failure Mode and Effects Analysis)

Can we use 250KW charger to charge a 20KW EV battery Vehicle ?

Yes, We can generally use a 250kW charger for a 20kW EV battery, but with some important thing need to remember :

Key Considerations

• Battery Management System (BMS): The car's BMS is crucial. It communicates with the charger to regulate the charging process. It will ensure that the battery receives the appropriate voltage and current, preventing damage from overcharging or excessive heat.

• Charging Rate Limit: Every EV battery has a maximum charging rate it can safely handle. Even if you plug into a 250kW charger, the BMS will limit the charging rate to the battery's maximum capacity. With a 20kW battery, the maximum charge rate will likely be significantly lower than 250kW.

• Charging Pattern: EV batteries don't charge at a constant rate. They typically charge faster initially and then gradually slow down as they approach full capacity. This is known as the charging curve. The BMS manages this process to optimize charging speed and battery health. 

What to Expect: 

• Faster Initial Charging: You might experience a faster initial charging rate compared to using a lower-powered charger, but this will quickly taper off as the battery gets closer to full.

• No Damage to the Battery: If your EV and its BMS are functioning correctly, using a higher-powered charger will not damage the battery. The BMS will act as a protector.

• Not Necessarily the Fastest Charge: While you can use a 250kW charger, it doesn't mean your 20kW battery will charge incredibly fast. The limiting factor is the battery's capacity and its maximum charging rate.

Example:

Take the case of the TATA Nexon Vehicle, The battery pack is 320V & 90AH Capacity, Energy is 28.8KWh.

The maximum energy the Nexon battery accepts for charging depends upon the BMS inside the battery pack and the nominal charging ampere of a 90AH battery is 45Amps, 

The 55KW charger can charge the 28.8KW Pack of Nexon Car with a maximum of 16.4KW , 

How. Since the Lithium cell's maximum voltage is 3.65v and we multiply 3.65*100 Cells is 365v. then multiply 365v*45A (Nominal Charging Current ) which is 16.4KW.

Note:

There are different types of chargers available,

1. Slow Chargers.

2. Fast Chargers.

3. Ultra Fast Chargers or rapid chargers.

To learn more about the types of chargers, click the below post...

The charging speed and time depend on the power supplied by each type of charger and also depend on the capacity of the battery.

In Summary

Using a 250kW charger with a 20kW EV battery is generally safe, thanks to the BMS. However, don't expect a dramatically faster charging time compared to a lower-powered charger. The battery's limitations will determine the actual charging speed.

Relationships Between Energy,Power & torque in EV Vehicles

 

High Torque, Low Power example

• Energy: The ability to do work.
• Torque: The twisting force that can cause rotation.  
• Power: How quickly work is done or energy is used.

Relationships Between Them

• Torque and Power: In rotating systems (like engines and motors), torque and power are directly related. Power is proportional to torque multiplied by rotational speed. This means that you can have high torque at low speeds or high power at high speeds.  

• Energy and Power: Power is the rate of energy use or transfer. If you use a lot of energy quickly, you have high power. If you use the same amount of energy slowly, you have low power.  

• Torque and Energy: Torque can be thought of as the "effort" that can transfer energy in a rotational system. The more torque you apply, the more energy you can potentially transfer (given enough rotation).

Major types of Electric Vehicles in the world

                    

Several types of electric vehicles (EVs) are available in the market, each with unique characteristics and ways of using electricity as a power source. Here's a breakdown of the main types:  

1. Battery Electric Vehicles (BEVs)  or Pure EVs

• How they work: These are "pure" electric vehicles that run solely on electricity stored in a battery pack. They have no internal combustion engine (ICE).  
• Key features:
• Plug-in charging: BEVs are plugged into an external power source (charging station or wall outlet).  
• Zero tailpipe emissions: They produce no emissions from the vehicle itself.  
• Examples: TATA Nexon, TATA Tiago, Mahindra XEV 9e and BE 6e, Tesla Model S etc...

2. Hybrid Electric Vehicles (HEVs)

• How they work: HEVs combine an electric motor with a traditional internal combustion engine (usually gasoline). The electric motor assists the engine, improving fuel efficiency.  
• Key features:
• Regenerative braking: HEVs capture energy during braking and use it to recharge the battery.  
• Cannot be plugged in: The engine and regenerative braking charge the battery, not an external source.
• Examples: Maruti Grand Vitara, Toyota Innova Hycross, Honda City e: HEV

3. Plug-in Hybrid Electric Vehicles (PHEVs)

• How they work: PHEVs are similar to HEVs, but they have a larger battery pack and can be plugged in to charge. They can also drive for a certain distance on electric power alone.  
• Key features:
• Dual power sources: Can run on electricity, gasoline, or a combination of both.
• Longer electric range than HEVs: Allows for some emission-free driving.  
• Examples: Chevrolet Volt, Toyota Prius Prime, Mercedes AMG GT 63 SE and BMW XM.

4. Fuel Cell Electric Vehicles (FCEVs)  

• How they work: FCEVs use a fuel cell to generate electricity from hydrogen. They combine hydrogen with oxygen from the air to produce electricity, with water as the only byproduct.  
• Key features:
• Refuelled with hydrogen: Similar to refuelling a gasoline car, but with hydrogen instead.
• Zero tailpipe emissions: Only emit water vapour.
• Examples: Toyota Mirai, Hyundai Nexo

	BEV	HEV	PHEV	FCEV
Power Source	Battery only	Engine + Electric Motor	Engine + Electric Motor + Plug-in Charging	Hydrogen Fuel Cell
Charging	Plug-in	Self-charging	Plug-in + Self-charging	Hydrogen refueling
Range	Long	Short	Medium	Long
Tailpipe Emissions	Zero	Reduced	Reduced/Zero (in EV mode)	Zero

What is Resolver in Electric Motor & How it Works?

AI-Generated Motor Resolver to determine the position of the rotor.

                             

The resolver is an electromechanical transducer or a rotary transformer that determines a motor's rotor position. The resolver is sometimes called as a Control Transmitter or Analog Trigonometric Function Generator.

The resolvers were initially developed for military applications to withstand harsh environments. Wherever we need to find the angular position of a rotary shaft we can use resolvers to measure it accurately and reliably.

Encoder:

Don't confuse a Resolver with an Encoder, Both are used to measure the speed and angular position of the rotating shaft, the main difference is the resolver is a mechanical device & the encoder is an electrically operated device and the output is analog in nature for resolver and digital in the encoder.

Let's dive deeper into how a resolver works.

Core Principle: Electromagnetic Induction

At its heart, a resolver functions based on the principle of electromagnetic induction, just like a transformer. This means that a changing magnetic field can induce an electrical current in a nearby conductor.

Think of it like a very precise dial:

• Imagine a dial that can tell you exactly how far it has turned. A resolver does something similar, but instead of a physical dial, it uses electrical signals.
• It has two main parts: a rotor (the part that turns) and a stator (the stationary part).
• These parts have wire coils that create magnetic fields. As the rotor turns, these magnetic fields change.
• These changes in the magnetic fields produce electrical signals that can be used to precisely determine the angle of the rotor.

Components:

1. Rotor: The rotating part of the resolver, typically with a single winding (coil of wire) called the excitation winding or primary winding.
2. Stator: The stationary part, usually with two windings placed at a 90-degree angle to each other. These are called the sine and cosine windings or secondary windings.

Working Mechanism:

R - Rotor (Excitation Winding)

S1 - Stator Winding

S2- Stator Winding

Note: The resolver's output is two sine and cosine waves that have a 90 electrical degree phase difference with respect to the reference voltage given in the Primary Excitation Winding.

Excitation: An AC (alternating current) voltage is applied to the rotor's excitation winding. This creates a magnetic field within the resolver.

From where the voltage is supplied from:

• Resolver-to-Digital Converter (RDC): An RDC is a specialized integrated circuit (IC) designed specifically to work with resolvers. It does several key things:

• Generates the AC excitation signal: The RDC produces the precise AC voltage at the correct frequency and amplitude needed for the resolver's reference winding.
• Processes the resolver's output signals: The RDC takes the sine and cosine signals from the resolver and converts them into a digital representation of the angle.

A simple electronic oscillator circuit can generate an AC signal. However, this is less precise and flexible than an RDC.

RDCs are designed to provide a very stable and accurate AC signal, which is crucial for precise angle measurement.

Magnetic Field Interaction: As the rotor turns, its magnetic field interacts with the stator windings. The strength of this interaction changes depending on the rotor's angular position.

Induced Voltages: This interaction induces AC voltages in the stator windings. The amplitudes (strengths) of these voltages vary sinusoidally with the rotor's angle.

• The voltage induced in one stator winding is proportional to the sine of the rotor angle.
• The voltage induced in the other stator winding is proportional to the cosine of the rotor angle.

Mathematical Representation:

If the excitation voltage applied to the rotor is:

• V_excitation = V_peak * sin(ωt) (where ω is the frequency of the AC signal)

Then the voltages induced in the stator windings are:

• V_sine = K * V_peak * sin(ωt) * sin(θ)
• V_cosine = K * V_peak * sin(ωt) * cos(θ)

Where:

• K is a constant related to the resolver's construction.
• θ is the angle of the rotor.

Determining the Angle:

By measuring the amplitudes of the sine and cosine voltages from the stator, the angle θ can be precisely calculated using trigonometric relationships.

Still confused about resolver, here is an analogy:

Imagine a flashlight inside a tube.

• The tube: This is like the body of the resolver.
• The flashlight: This is like the "reference winding" in the resolver. It sends out light (or in the resolver's case, an electrical signal).
• Two light sensors on the tube's wall: These are like the "sine and cosine windings." They measure how much light hits them.

Now, imagine you can rotate the flashlight inside the tube.

• When the flashlight points directly at one sensor, that sensor gets the most light. The other sensor gets very little.
• As you rotate the flashlight, the amount of light hitting each sensor changes. Sometimes one gets more, sometimes the other.

This is similar to how a resolver works:

• The "flashlight" (reference winding) sends out an electrical signal.
• As the resolver's shaft rotates, it changes how much of that signal reaches the two "sensors" (sine and cosine windings).
• The amount of signal each sensor receives follows a sine wave and a cosine wave pattern as the shaft turns.

Hope you get an idea of how a resolver works inside an edrive or motor.

Why are resolvers used?

Resolvers are popular in applications where accuracy and reliability are crucial, such as:

• Robotics: To precisely control the movement of robotic arms.
• Aerospace: In aircraft control systems and navigation.
• Industrial automation: In machines that require precise positioning.
• Electric vehicles: To accurately control the motor and ensure smooth operation.

Advantages of resolvers:

• High accuracy: They can provide very precise measurements of rotation.
• Robustness: They can withstand harsh environments, including high temperatures, vibration, and shock.
• Reliability: They have a long lifespan and require minimal maintenance.

In essence, a resolver is a robust and accurate sensor that provides precise information about the rotational position, making it essential in various demanding applications.

What are the do's and dont's to keep Lithium Ion battery Safe & Healthy?

 

Lithium Iron Phosphate (LiFePO4) cells arranged in parallel to increase capacity; 3.2V 700AH

The industry follows some dos and don'ts for the safe operation of LFP(Lithium Ferrous Phosphate) or any other lithium-based batteries, which are as follows.

Do's:

1. Store at Ideal SOC: Always store lithium batteries or EV batteries at an ideal state of charge (SOC) between 40% and 60% for longer periods.

2. Hazardous Safety: Keep the batteries away from hazardous materials, such as fire, oils, explosives, and similar substances.

3. Adequate Ventilation: Ensure adequate ventilation if storing more than one lithium battery in a single location.

4. Optimal temperature: Store lithium batteries at an optimal temperature range of 20°C to 45°C.

5. Optimal Charge: Charge the EV battery or vehicle to 100% SOC at least once a week to calibrate the Battery Management System (BMS) for SOC correction.

6. Physical Verification: During general service checks at the dealership, inspect for any dents or rust underneath the tray of the lithium battery.

Don'ts:

1. Avoid Using Incompatible Chargers: Do not charge lithium-based batteries with chargers meant for VRLA or lead-acid batteries. Always use the charger provided by the original equipment manufacturer (OEM), or ensure that any alternative charger is equipped with the appropriate charging methodology for lithium batteries.

2. Optimal State of Charge (SoC): Lithium-ion batteries should be stored at 50% to 60% of their state of charge for long durations (2 to 4 months). Additionally, it's important to top up the charge every 6 months if the battery is not in use.

3. Charging Speed Matters: Avoid ultra-fast chargers, as they can impose high stress on the battery and reduce lifespan. While occasional fast charging is acceptable, it’s always preferable to use slow charging methods.

4. Regular Charging: Users should charge the battery to full at least twice a week and ensure that the state of charge does not drop below 20%. Both high and very low SOC can damage lithium battery cells.

5. Temperature Considerations: Do not charge the battery in extremely cold temperatures. 

By following these guidelines, you can ensure safer and more reliable operation of lithium-based batteries.

 

What is an Electric Motor and its workings in detail ?

 

Image 1: AI Generated EV vehicle electric motor

To know about basics of electric motor , Lets rewind the basics of Physics which will be useful for this topic.

Fundamental Physics:

1. Force: A Push or Pull experinced by any object is called a force.

2. Current: Movement of electrons in a conductors causes current to flow from higher potential to lower Potential ( Like Water as a current moves from Tank to a small Tap).

3. Electron: Electron is a fundamental subatomic particle and , it is also known as an elementary particle because it can't be break into any other sub particle.

Electron flows from Negative of the power source to the Positive, Since electron have -ve Charge and only electron moves in an atom unlike Proton & Neutron so the movement of electron will be from Negative to Positive in a source like Battery.

4. Magnetic Field: It is an invisible Force (Lorentz Force) that an Object or Charge carriers (Electrons,Holes,Ions) experinces around a magnetic material like Magnets.

5. Fleming's Left Hand Rule:

Image 2: Fleming's Left Hand Rule , Rajiv1840478, CC BY-SA 4.0, via Wikimedia Commons

As shown in the above image,The Fleming's left hand rule is applicable only for Motors, Which says whenever an conductor placed in a magnetic field the conductor experinces a Force (F) which will be perpendicular to the dirction of  Magnetic Field (B) and the Current (I).

6. Fleming's Right Hand Rule: 

Image 3: Fleming's Right Hand Rule , Douglas Morrison DougM, CC BY-SA 3.0

As shown in the above image (2),The Fleming's right hand rule is applicable for Generators, Which says whenever an conductor is moved in a magnetic field an emf will be induced across the conductor and if the conductor is in a closed path or loop then the induced emf will cause a current to flow.

 The Direction of movement of Conductor (F) which will be perpendicular to the dirction of  Magnetic Field (B) and the Current (I).

DC Motor:

Image 4: Rotation of Rotor inside an Electric Motor

A Motor is a device which converts input electrical energy to output mechanical energy. 

Components of a Simple DC Motor:

A Motor consists of major components which are,

1. Stator (D) - It is a static segment of a motor in which magnetic fields are created by Permanent Magnet or Electromagnet.

2.Rotor/Armature (C) - It is a rotating segment of a motor which is made up of steel,copper coils and a shaft.

3.Commutator (A) - It is a segment of the rotor in which the terminals of the rotor winding is conneted which periodically revereses the direction of the supplied current through brushes.

4.Brushes (B) - It is used to transfer power from the fixed electrical contact or wire to the rotating commutator.

Image 5: Original work: UlfbastelDerived work: Chetvorno, Public domain, via Wikimedia Commons

Image 6: Electric Motor working Principles

Working of a Electric Motor:

The above image is a simple model that explains the working of an electric motor.

The Magnets magnetic fields always travel from Northpole to Southpole outside magnets and from S to N inside the magnets.

The Magnetic field lines are drawn from N ----> S that is denoted as letter (B) in the above image.

Direction of Force exerted is denoted by letter (F) & Current as (I).

As per Feradays Left hand Rule which is applicable only to Motors, When we supply power to the armature carrying coils, a magnetic field will be generated and interacts with the stators magnetic field since the opposite poles of the magnets attracts each other the rotor starts to rotate a half. 

But there is an issue still not seen , The Motor can't rotate another half because the magnetic field of rotor and stator is in parellel and alligned now.

The solution is to either flip the magnets or to flip the power source like battery for every half cycle but the easier and the effective method to resolve this problem is to introduce a segment called Commutator.

The commutator is a circular split type ring and its job is to flip the polarity of current supplied through the brushs. The brush is a fixed contact or a metal piece which will be in contact with the commutator always.

The Commutator rotates with the armature or rotor but the power supplying brushes are in fixed position so that the polarity of current is fliped for every half rotation.

This resolves the issue and the motor will rotate contineously. 

The torque of the motor can be varied by either improving the strength of the magnetic field by increasing the cross section of the coil or by increasing the number of turns of the coil or by increasing the current flowing through the coil.

Know about types of Motors used in Electric Vehicles.......... Click here

What are IP Ratings?Types of IP ratings

                                           

What are IP Ratings?

IP rating or Ingress Protection Rating are the indicator which defines the protection of electrical or Mechanical enclosures Components from the external Intruders like Water,Dust,Oil splash etc...

or simply IP Ratings shows how any enclosure is protected against Water and Solids.

The IP rating has a two digit number after a letter IP X X (X)--->optional

IP - Ingress Protection

X - Solids ( Dust,sand etc..)

X - Liquids ( Moisture,Oils,Water etc..)

X - Pressure (Optional)

Note: The Higher the number after IP ,the better the Protection.

IP Ratings