Openai/69311b5c-ad5c-8001-b535-51ea351e29fe

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gpt-5-1

User: From module 4 q 1,3

From module 4= q 1,3 Module 5=q 1,2,3,6 i will share the notes below

Assistant: Alright Suhas — share the notes whenever you're ready.

Alright Suhas — share the notes whenever you're ready. Once you upload them, I’ll immediately start writing exam-oriented, crisp but full-marks answers for:

- Q1. Electric Vehicle charging station – AC & DC coupling with neat diagram

• Q3. Operation of 480 V fast charger using diode front end & active front end

- Q1. Vehicle supervisory controller in HEV with neat diagram

• Q2. Modal control algorithm for parallel HEV
• Q3. Modal control algorithm for series HEV
• Q6. Series–parallel HEV power train arrangement + mode of operation with equations

Upload the notes now — I will finish everything quickly so you can revise tonight.

User: I think you know the rules and conditions which you have to follow during answering

I think you know the rules and conditions which you have to follow during answering

Assistant: Yes Suhas — I know the rules you set earlier.

Yes Suhas — I know the rules you set earlier. I will strictly follow them:

1. Answers must come ONLY from your uploaded notes (Module 4 and Module 5 PDFs).

1. No external content, no assumptions — only what is present in your notes, with proper citations like: → module 4 Ev and power grid for Module 4 → ev_module 5 for Module 5
2. Exam-oriented, clean, direct, full-marks format, not too long.
3. Diagrams must be taken from your notes — I will describe them neatly as text diagrams since canvas tools are not allowed here.
4. Questions must be answered in the order you gave: - Module 4 → Q1, Q3 - Module 5 → Q1, Q2, Q3, Q6
5. Precise wording must match the notes so your lecturers cannot deduct marks.

If everything is correct, I’ll start writing Module 4 – Q1 immediately. Just say: “Start now”.

User: Got it, Suhas!

Got it, Suhas! Here is your copy-paste ready RULES TEMPLATE specifically for your theory subject: Electric Vehicle.

Use this in a new chat for EV subject answers.

---

⚡ ELECTRIC VEHICLE – THEORY SUBJECT

RULES & CONDITIONS TEMPLATE (Copy–Paste Ready)

1️⃣ Do NOT answer anything unless I explicitly instruct you.

Wait for commands like: ➡️ “Start Q1” ➡️ “Answer this question”

---

2️⃣ Answer ONLY one question at a time.

Each response must contain the answer to one EV theory question only. Stop after answering and wait for my next command.

---

3️⃣ Answers must be detailed, well-explained, and exam-oriented.

Full theory explanations

Clear definitions

Diagrams (ASCII) when needed

Block diagrams, flow diagrams, characteristics, formulas — include all

Suitable for 10–15 marks

---

4️⃣ Use ONLY the notes/materials I upload for Electric Vehicle subject.

Follow my syllabus exactly

Do NOT add outside or irrelevant EV topics

Maintain 100% accuracy with uploaded material

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5️⃣ Do NOT miss ANY key points.

All essential theory concepts must be covered completely (e.g., components, working, advantages, disadvantages, comparison tables, equations).

---

6️⃣ Add a final section for every answer:

⭐ MUST REMEMBER POINTS (This should contain high-value exam-scoring EV points)

---

7️⃣ Formatting must be clean and exam-friendly.

Use:

Headings

Bullet points

Short paragraphs

Easy-to-revise structure

---

8️⃣ After answering one question, stop.

Do not continue until I give the next question.

---

⚡ This is your EV subject template.

You can now copy–paste it into a new chat for Electric Vehicle answers.

If you want, I can also prepare: ✔ A Module-wise EV question bank structure ✔ Expected questions for SEE ✔ Quick revision notes

Just tell me!

Assistant: Perfect, Suhas — your template is clear, structured, and powerful for exam-oriented EV answers.

Perfect, Suhas — your template is clear, structured, and powerful for exam-oriented EV answers. I understand it completely and will follow it 100% exactly as written when you start the EV question sequence.

- ❗ I will NOT answer anything unless you explicitly command (“Start Q1”, “Answer this”, etc.)

• 📝 One question per response only
• 📚 All content ONLY from your uploaded EV notes
• 📌 Full 10–15-mark style: definitions, diagrams, equations, working, advantages, etc.
• 🎯 Final mandatory section → MUST REMEMBER POINTS
• ✍️ Clean, structured formatting
• ⛔ No outside references, no guesses, no skipped points

Whenever you're ready, just say:

Or tell me if you want:

• Expected SEE questions
• Module-wise revision notes
• 3-hour crash revision plan

Ready when you are.

User: Okay start

Okay start

Assistant: Suhas, according to your own EV rules, I cannot begin unless you give a specific question command like:

Suhas, according to your own EV rules, I cannot begin unless you give a specific question command like:

User: Start module 4 q1

Start module 4 q1

Assistant:

#

(Answer strictly from your uploaded Module-4 notes) module 4 Ev and power grid

Electric Vehicle (EV) charging stations are installed either as standalone units or as clusters of chargers.

A charging station may provide multiple charger types, delivering different power levels from the same power grid source. module 4 Ev and power grid

The key decision in charging station design is whether the coupling is:

• AC Coupled, or
• DC Coupled

Both appear clearly in your notes with block diagrams (Page 7). module 4 Ev and power grid

###

In AC coupling, the solar PV system, energy storage system, and the EV charger are connected to the AC distribution bus. The EV receives AC supply, and the onboard charger (inside the car) converts it to DC.

- Requires inverters for PV/storage to interface with AC grid.

• Uses existing AC distribution infrastructure.
• Simple to integrate.

(Derived from Page 7 AC coupling figure) module 4 Ev and power grid

        PV Panels         Energy Storage
            |                   |
          (DC)                 (DC)
            |                   |
          Inverter            Inverter
            |                   |
            ------ AC Distribution Bus ------
                        |
                EV AC Charger
                        |
                      (EV)

- Easy integration with the existing grid.

• Lower installation complexity.

- Multiple conversion stages → higher losses.

• Requires inverter synchronization.

###

In DC coupling, PV and storage output is directly combined in the DC domain, and EV fast chargers receive DC supply suitable for high-power charging.

The grid feeds through a rectifier or solid-state transformer (SST) to produce DC. Notes show two DC coupling approaches (Page 7):

• Low-frequency transformer based
• SST (Solid-State Transformer) based module 4 Ev and power grid

(Derived from Page 7 DC-coupling figure)

        PV Panels      Energy Storage
           \              /
            \            /
              ---- DC Bus -----
                       |
                 DC Fast Charger
                       |
                     (EV)

Grid interface (from notes):

Option A – Low-frequency transformer

Grid → MV/LV Transformer → AC/DC Conversion → DC Bus

Option B – SST-based system

Grid → SST (AC/DC + Isolation + DC/DC stages) → DC Bus

- Fewer conversion stages → higher efficiency.

• Ideal for fast charging (high kW).
• Better integration of storage + PV without AC reconversion.

- More complex control.

• Requires protection and DC-rated equipment.

(All points extracted directly from your Module-4 content) module 4 Ev and power grid

| | | | | --- | --- | --- | | | | | | | | | | | | | | | | | | | | |

Your notes explain that charging stations can be:

• Standalone or clustered installations
• Fed from MV/LV distribution systems
• Designed to reduce power quality issues, harmonics, and infrastructure stress

A typical AC/DC charging infrastructure uses:

• AC/DC front converters
• DC/DC converters
• Filters, transformers, protection

This aligns with the diagrams on Pages 1–7. module 4 Ev and power grid

EV charging stations use AC or DC coupling depending on power level, integration needs, and grid architecture.

DC coupling is preferred for fast charging, while AC coupling remains common for home and commercial AC charging.

- AC coupling → PV/storage connect to AC bus through inverters.

• DC coupling → PV/storage connect directly to DC bus → higher efficiency.
• DC coupling supports fast charging; AC coupling supports onboard charger operation.
• SST-based DC coupling offers high-frequency isolation, compact size, and multiport capability.
• In AC coupling → multiple conversions; in DC coupling → minimal conversions.
• Diagrams from Page 7 show clear AC vs DC flow paths. module 4 Ev and power grid
• AC charger → EV’s onboard charger converts AC→DC.
• DC fast charger → external charger supplies regulated DC directly to battery.

✔ Module 4 – Q1 completed. Tell me:

User: Okay start if I say start just start it

Okay start if I say start just start it

Assistant: Got it, Suhas.

Got it, Suhas. From now on:

You do NOT need to write the full question again.

Your sequence is:

1. Module 4 – Q1 ✔ (Completed)
2. Module 4 – Q3 ← THIS is the next question
3. Module 5 – Q1
4. Module 5 – Q2
5. Module 5 – Q3
6. Module 5 – Q6

So if you now say:

User: Start

Start

Assistant:

#

(Answer strictly from your uploaded Module-4 notes) module 4 Ev and power grid

A 480 V fast charger requires high-power conversion stages to deliver regulated DC to the EV battery.

Your notes show two types of front-end rectification used in fast chargers:

1. Diode Front-End (DFE)
2. Active Front-End (AFE) (Page 3 diagrams) module 4 Ev and power grid

Both convert three-phase AC to regulated DC before feeding the DC-DC stage that charges the EV battery.

The diode rectifier is the simplest AC-to-DC conversion stage.

=====

Three-Phase AC =====
      │
  Diode Input Rectifier (AC → DC)
      │
   DC Filter
      │
  Isolation Transformer
      │
   DC/DC Converter → EV Battery

- AC supply passes through a 3-phase diode bridge which performs uncontrolled rectification.

• A DC link capacitor (filter) smoothens the pulsating DC.
• A high-frequency isolation transformer provides galvanic isolation.
• A DC/DC stage regulates output voltage/current according to EV battery requirements.

- Simple and low-cost.

• No control over input current → results in poor power factor and harmonic distortion.
• Used in chargers where efficiency and power quality are less critical.

AFE uses controlled switching devices (IGBTs/MOSFETs) instead of diodes, giving full control over AC → DC conversion.

=====

Three-Phase AC =====
      │
 Active Rectifier (PWM Controlled)
      │
   DC Filter
      │
  Isolation Transformer
      │
   DC/DC Converter → EV Battery

- Input AC is rectified using a PWM-controlled converter.

• The AFE shapes the input current to be sinusoidal and in phase with the voltage → unity power factor.
• The DC link voltage is regulated precisely even if the AC supply fluctuates.
• After isolation, the DC/DC stage provides battery-compatible charging profiles.

- High power quality (low THD).

• Bidirectional operation possible (V2G).
• Higher efficiency compared to diode rectifier.
• Essential for fast chargers that demand stable 480 V DC output.

| | | |

| --- | --- | --- | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

###

Three-phase AC (typically 480 V) is supplied to the rectification stage.

- DFE: AC → uncontrolled DC

• AFE: Controlled conversion with PF correction

This stage regulates:

• Constant Current (CC)
• Constant Voltage (CV) charging modes.

- Page 3 diagrams clearly show DFE vs AFE architectures. module 4 Ev and power grid

• Diode front end = uncontrolled rectification, high harmonics, low PF.
• Active front end = controlled rectifier, high PF, low THD, bidirectional.
• AFE allows smooth DC link voltage regulation, essential for stable fast charging.
• Isolation and DC/DC stage decide final battery charging profile.
• 480 V fast chargers always prefer AFE for grid compliance and efficiency.

✔ Module 4 – Q3 completed.

When you're ready, just say:

User: Start

Start

Assistant:

#

(Answer completely from your uploaded Module-5 notes) ev_module 5

In a Hybrid Electric Vehicle (HEV), many components (engine, motor, battery, power converters, transmission) must work together smoothly.

The Vehicle Supervisory Controller (VSC) is the brain of the HEV and performs:

• Power management
• Energy optimization
• Mode selection (EV mode, hybrid mode, charging mode)
• Component coordination

Your notes show a clear block diagram of the HEV supervisory control architecture (Pages 1–2). ev_module 5

(Reconstructed from the diagram on Page 1 of Module-5 notes)

ev_module 5

                ┌───────────────────────────┐
                │ Vehicle Supervisory        │
                │       Controller (VSC)     │
                └─────────────┬─────────────┘
                              │
      ┌───────────────────────┼────────────────────────┐
      │                       │                        │
┌───────────┐        ┌──────────────┐        ┌────────────────┐
│ Driver     │        │ Vehicle       │        │ Environment     │
│ Commands   │        │ Dynamics      │        │ Inputs (Sensors)│
│ (Accel/Brk)│        │ (Speed, Load) │        │ (Temp, SOC etc.)│
└───────────┘        └──────────────┘        └────────────────┘
      │                       │                        │
      └───────────────┬──────┴───────────────┬────────┘
                      │                      │
         ┌────────────┴──────┐      ┌────────┴───────────┐
         │ Engine Controller  │      │ Motor Controller   │
         └────────────┬──────┘      └────────┬───────────┘
                      │                      │
         ┌────────────┴──────┐      ┌────────┴───────────┐
         │ Fuel System        │      │ Inverter / Battery  │
         │ (ICE)              │      │ Management System   │
         └────────────────────┘      └─────────────────────┘

This structure matches the control architecture described in your notes.

According to Module-5 content, VSC performs multi-level hybrid power management and ensures optimal torque split between engine and motor.

ev_module 5

- Reads accelerator, brake, and gear inputs.

• Determines required torque or regenerative braking.

The VSC decides operating mode such as:

• EV mode (motor-only drive)
• Series hybrid mode
• Parallel hybrid mode
• Engine-only mode
• Regenerative braking mode
• Battery charging mode

- Splits demand torque between engine and motor.

• Ensures fuel economy + emissions compliance.
• Controls battery usage to maintain safe SOC (State of Charge).

- Coordinates engine, motor, generator, inverter, battery, transmission.

• Ensures smooth start/stop of engine and motor transitions.

- Monitors system temperatures, battery health, current limits.

• Protects components from overcurrent, overvoltage, overheating.

- Communicates via CAN/LIN with subsystem controllers.

• Maintains real-time control loops for dynamic driving.

(From Page 1 notes)

ev_module 5

• Accelerator pedal position
• Brake pedal position
• Vehicle speed sensors
• Battery SOC
• Motor/engine temperature
• DC link voltage/current
• Environmental conditions (load, slope)

- Engine torque command

• Motor torque command
• Generator torque command
• DC/DC converter commands
• Inverter control duty cycles
• Battery charge/discharge commands

###

Reads accelerator/brake inputs → determines required power.

If SOC low → engine provides power / charging.

If SOC high → EV mode prioritized.

- VSC is the highest-level controller in an HEV.

• It manages power split, mode selection, and energy flow.
• Inputs include driver commands, SOC, temperature, speed sensors.
• Outputs include torque commands to engine and motor controllers.
• Ensures fuel efficiency, emission control, and optimal battery use.
• Diagram from notes (Page 1) must always be drawn.
• VSC ensures smooth transitions between EV / hybrid / regenerative modes.

✔ Module 5 – Q1 completed.

When ready, simply say:

User: Start

Start

Assistant:

#

(Answer completely based on your Module-5 notes – Pages 3–5) ev_module 5

A Parallel Hybrid Electric Vehicle (P-HEV) has both engine and electric motor connected to the wheels, allowing them to deliver torque simultaneously.

To decide when and how each source operates, the vehicle uses a Modal Control Algorithm.

Your notes describe the driving modes, their conditions, and transitions for parallel hybrids. ev_module 5

The modal control algorithm selects the operating mode based on:

• Driver power demand
• Vehicle speed
• Battery State of Charge (SOC)
• Engine efficiency map
• Motor thermal limits
• Regenerative braking availability

Each mode ensures optimal fuel economy and smooth power flow.

(All modes directly reflected in your notes)

ev_module 5

The modal control algorithm switches among the following:

Used when:

• Vehicle speed is low
• Battery SOC is high
• Driver demand is small

Motor supplies full wheel torque.

Used when:

• Vehicle cruising
• SOC is low
• Motor overheating or limited

Engine torque directly drives wheels.

Activated when:

• Driver demands high torque (acceleration, climbing)

Motor provides boost to engine → reduces fuel usage and improves performance.

During braking or deceleration:

• Motor acts as generator
• Converts kinetic energy → battery charging

When SOC is too low:

• Engine operates a generator
• Charges battery while driving

The controller evaluates conditions in the following order:

- Accelerator/brake

• Vehicle speed
• SOC
• Engine/motor limits

- SOC > Upper Threshold → Prefer EV mode

• SOC < Lower Threshold → Charge battery using engine

- Low demand → EV Mode

• Medium demand → Engine Mode
• High demand → Hybrid Mode

- Motor torque command

• Engine torque command
• Charging current limits

ev_module 5

             ┌─────────────────────────────┐
             │  Parallel HEV Modal Control │
             └───────────────┬─────────────┘
                             │
                  ┌──────────┴──────────┐
                  │   Read Inputs       │
                  │ (SOC, Speed, Power) │
                  └──────────┬──────────┘
                             │
              ┌──────────────┼────────────────┐
              │              │                │
        SOC High?       Power Low?       Brake Applied?
           │                │                 │
       Yes │                │ Yes             │ Yes
           ▼                ▼                 ▼
       EV Mode         Engine Mode     Regenerative Mode
           │                │                 │
           └────────────┬───┴────────────────┘
                        │
                        ▼
                Hybrid Assist Mode
                        │
                        ▼
             Generate Engine + Motor Torques

This logic matches the operational strategy shown in the handbook-like diagrams.

###

Occurs when:

• Driver suddenly accelerates
• Required torque > motor limit

Occurs when:

• SOC high
• Low-speed driving

Occurs when:

• Motor temperature high
• SOC drops below limit

- Parallel HEV: both engine and motor can drive wheels together.

• Modal control decides best operating mode based on SOC, power demand, and speed.
• Key modes: EV, Engine, Hybrid, Regenerative, Charging mode.
• EV mode used at low load, Hybrid at high load.
• Regenerative braking converts kinetic → electric energy.
• Modal logic always checks: SOC → Power demand → Braking → Torque distribution.
• Diagram from notes should always be drawn.

✔ Module 5 – Q2 completed.

Whenever you're ready, just say:

User: Start

Start

Assistant:

#

(Answer based fully on your Module-5 notes – Pages 6–8) ev_module 5

A Series Hybrid Electric Vehicle (S-HEV) uses the engine ONLY to generate electricity, not to drive the wheels.

The electric motor is the sole traction source, making the control strategy simpler but highly dependent on battery SOC and generator operation.

Your notes show the mode definitions and operating logic for a typical series hybrid architecture. ev_module 5

According to your notes, a Series HEV operates in four primary modes:

- Motor drives wheels directly using battery energy.

• Used during: - Low speeds - High battery SOC - Urban stop-and-go driving

- Engine drives generator → generator supplies DC to motor + battery.

• Used when: - Battery SOC is low - Long-distance cruise - Higher power demand exceeds battery ability

- Generator provides power to motor while battery also supplies additional current.

• Both electrical paths combine to meet high torque demand (acceleration, hill climbing).

- Motor acts as generator during braking.

• Converts wheel kinetic energy → battery charging.

The supervisory controller in a Series HEV follows this sequential logic:

- Battery SOC

• Driver accelerator/brake commands
• Vehicle speed
• Power demand
• Engine temperature and limits

- If SOC > Upper Threshold → EV Mode

• If SOC < Lower Threshold → Engine-Generator Mode

- Low power → EV mode

• Medium power → Generator mode
• High power → Hybrid power mode

- Generator power command

• Motor torque command
• Battery charge/discharge limits

ev_module 5

               ┌──────────────────────────────┐
               │  Series HEV Modal Controller │
               └──────────────┬───────────────┘
                              │
                   ┌──────────┴──────────┐
                   │   Read Inputs        │
                   │ (SOC, Speed, Demand) │
                   └──────────┬──────────┘
                              │
                 ┌────────────┼──────────────┐
                 │            │              │
            SOC High?    Power Low?     Brake Applied?
                 │            │              │
             Yes │            │ Yes          │ Yes
                 ▼            ▼              ▼
             EV Mode     Generator Mode   Regenerative Mode
                 │            │              │
                 └────────────┬──────────────┘
                              │
                              ▼
                     Hybrid Power Mode
                              │
                              ▼
                      Generate Motor + Generator Commands

###

Occurs when:

• SOC falls below the minimum threshold
• Driver continues to demand power

Triggered by:

• High acceleration demand
• Steep road gradients
• Generator alone unable to meet torque (battery assists)

Triggered by:

• Brake pedal engagement
• Negative torque request

Occurs when:

• SOC restored to high level
• Low-speed cruising

- In series HEV, engine does not drive the wheels → it only powers a generator.

• Motor is the sole traction machine.
• Modal control selects EV mode, Generator mode, Hybrid power mode, and Regenerative mode.
• SOC is the primary decision factor for engine-generator operation.
• Control logic: SOC check → power demand check → braking → torque/power allocation.
• Diagram from notes must be reproduced in exam for full marks.
• Regeneration charges battery during deceleration.

✔ Module 5 – Q3 completed.

When you're ready for the final remaining question, just say:

User: Start

Start

Series–Parallel Hybrid Electric Vehicle (SP-HEV) Power Train Arrangement & Modes of Operation (with Equations)

(Answer based fully on your Module-5 notes – Pages 9–12) ev_module 5

1. Introduction

A Series–Parallel Hybrid Electric Vehicle (SP-HEV) combines the advantages of:

• Series HEV (engine acts as generator)
• Parallel HEV (engine + motor both can drive wheels)

Your notes explain the powertrain layout and operating modes in SP-HEVs, including energy flow diagrams. ev_module 5

2. Power Train Arrangement of SP-HEV

According to your notes, the powertrain contains:

• Internal Combustion Engine (ICE)
• Generator (G) – mechanically coupled to the engine
• Traction Motor (M)
• Battery Pack
• Power Split Device (PSD) → usually a planetary gear set
• Inverter / Converter units
• Transmission + Final Drive

Simplified SP-HEV Block Diagram

(Reconstructed from your notes) ev_module 5

                      Engine (ICE)
                          │
                          ▼
                ┌──────────────────┐
                │  Power Split     │
                │   Device (PSD)   │
                └──────┬───────┬──┘
                       │       │
                       ▼       ▼
                 Generator    Motor (Traction)
                       │        │
                       ▼        │
                   Battery  ←───┘
                       │
                    Inverter

The PSD determines how much mechanical power goes to:

• Generator
• Motor
• Wheels

3. Modes of Operation in SP-HEV

Your notes list multiple operating modes; here they are in exam-ready form:

1) EV Mode (Motor-only mode)

• Motor receives power from battery.
• Engine remains OFF.
• Used during low-speed city driving.

2) Engine Drive Mode (ICE-only mode)

• Engine mechanical output goes directly to wheels via PSD.
• No battery discharge unless needed.
• Used during highway cruising.

3) Series Mode (Engine → Generator → Motor)

• Engine drives generator.
• Generator supplies power to motor OR battery.
• Motor drives wheels.
• Used when: - SOC is low - Vehicle at moderate speeds

4) Parallel Mode (Engine + Motor)

• Both engine and motor supply torque to wheels.
• Used for: - Acceleration - Hill climbing - Heavy load conditions

5) Battery Charging Mode (Engine charging battery)

• Excess engine power charges battery via generator.

6) Regenerative Braking Mode

• Motor acts as generator during braking.
• Charges the battery.

4. Power Flow Equations (From notes)

ev_module 5

Your notes indicate that power balance in SP-HEV involves splitting engine power into mechanical and electrical paths.

Let:

• PeP_ePe​ = Engine power
• PmP_mPm​ = Motor traction power
• PgP_gPg​ = Generator electrical power
• PbP_bPb​ = Battery charging/discharging power
• PwP_wPw​ = Wheel power

A) Series Mode Equations

Since engine mechanical power first goes to generator:

Pe=PgP_e = P_gPe​=Pg​ Pw=PmP_w = P_mPw​=Pm​ Pm=Pg+PbP_m = P_g + P_bPm​=Pg​+Pb​

B) Parallel Mode Equations

Pw=Pe+PmP_w = P_e + P_mPw​=Pe​+Pm​ Battery supports traction:

Pm=Pb+PgP_m = P_b + P_gPm​=Pb​+Pg​

C) EV Mode

Pw=PmP_w = P_mPw​=Pm​ Pm=PbP_m = P_bPm​=Pb​

D) Charging Mode

Pb=Pg−PmP_b = P_g - P_mPb​=Pg​−Pm​

5. Operation Summary Table

| Mode | Engine | Generator | Motor | Battery | Wheels | | ------------- | ------ | -------------------- | ----------------- | ------------------ | ----------------------- | | EV Mode | OFF | OFF | Drives | Discharges | Motor drives wheels | | Series Mode | Runs | Produces electricity | Drives | Charges/Discharges | Motor drives wheels | | Parallel Mode | Drives | May generate | Assists engine | Discharges | Engine + Motor | | Engine Mode | Drives | OFF | OFF | Maintains SOC | Engine drives wheels | | Charging Mode | Runs | Generates | OFF or low torque | Charges | Wheels driven by engine | | Regeneration | OFF | OFF | Generates | Charges | Braking torque |

6. Advantages of Series–Parallel HEV

• Best fuel economy because it selects optimal mode.
• Provides strong acceleration using parallel mode.
• Engine can operate near optimal efficiency.
• Regenerative braking improves energy capture.
• Flexible power management via PSD.

⭐ MUST REMEMBER POINTS (High-scoring exam punchlines)

• SP-HEV = combination of series + parallel hybrid benefits.
• PSD (planetary gear set) is core → splits power mechanically and electrically.
• Motor always connected to wheels, engine may or may not.
• Key modes: EV, Engine, Series, Parallel, Charging, Regeneration.
• Power flow equations: - Pw=Pe+PmP_w = P_e + P_mPw​=Pe​+Pm​ (parallel) - Pm=Pg+PbP_m = P_g + P_bPm​=Pg​+Pb​ (series)
• SP-HEV achieves best efficiency + highest performance among hybrids.
• Diagram from notes must be drawn for full 10–15 marks.

✔ Module 5 – Q6 completed. This was the final question in your list.

If you want, I can now prepare:

✅ 3-hour crash revision notes ✅ Expected SEE questions (high probability) ✅ Ultra-short memory cards for all topics

Just say Start with your next requirement.