What is EV Charger?
The plug or connector at the end of a charging cable that connects an electric vehicle (EV) to a charging station is known as an EV charger gun. It's often referred to as the charging nozzle or charging handle. It physically and electrically connects the vehicle to the power supply.
Types of EV Charger Guns
Various connector standards exist based on the region and charging level (DC or AC):
AC Charging (Level 1 & 2)
- Type 1: Mostly utilized in North America and Japan.
- Type 2 (Mennekes): Common in Europe, India, and other regions.
- Type 3: Rare, mainly used in France/Italy; being phased out.
Level 3 DC Fast Charging
- CCS1: Combines Type 1 and DC pins (North America).
- CCS2: Combines Type 2 and DC pins (Europe and other regions).
- CHAdeMO: Japanese standard for fast DC charging.
- GB/T: China’s AC and DC charging standard.
ISO/IEC Standards for Testing of EV Gun
- IEC 61851-1: General requirements for AC and DC EV chargers.
- IEC 61851-21-2: Electromagnetic compatibility testing during charging.
- IEC 61851-23: Performance and test requirements for DC chargers.
- IEC 61851-24: Communication protocol between EVSE and EV during DC charging.
- IEC 62196-1: Mechanical, electrical, and thermal tests for connectors.
- IEC 62196-2 / -3: Specs and tests for Type 2, CCS, CHAdeMO connectors.
- IEC 60364-7-722: Guidelines for electrical installation at EVSE.
- IS 17017 (India): Indian standard derived from IEC 61851.
Key Test Categories Covered by These Standards
Electrical Tests
- Output voltage and current accuracy
- Load regulation (static and dynamic)
- Power factor and harmonic distortion (THD)
- Ground fault current detection
- Voltage ripple (DC chargers)
Thermal Tests
- Temperature rise at connector terminals
- Long-duration full-load soak testing
- Ambient vs surface temperature behavior
Mechanical Tests
- Connector insertion/withdrawal force
- Durability (cycles of operation)
- Cable bend/flex tests
Typical Load Bank Test Reference from IEC 61851
IEC 61851-1
Testing with a load bank falls under:
- Clause 6: Protection against electric shock
- Clause 7: Constructional requirements
- Clause 8: EMC performance
- Clause 11: Tests for conformity
IEC 62196-1
- Section 12: Temperature-rise test under continuous rated current for connectors and cables
Dynamic Features for Testing an EV Charger Gun Using a Load Bank
Load Step Response
Purpose: Check the charger’s ability to maintain stable output voltage during sudden load changes.
Test: Apply a sudden change (step) in load, e.g., from 20% to 80%.
Observe:
- Output voltage dip/surge
- Response time (time to recover)
- Control Pilot (CP) stability
Acceptance: Output should recover within ±5% in under 100 ms (typical).
Ramp Load Test
Purpose: Verify performance as load gradually increases/decreases.
Test: Apply a linear ramp from 0 to 100% rated load.
Observe:
- Voltage regulation
- Smooth current increase
- Connector heating (thermal imaging recommended)
Acceptance: No tripping, arcing, or deviation from rated specs.
Load Regulation
Purpose: Evaluate voltage stability under varying load conditions.
Test: Apply many load points: 25%, 50%, 75%, and 100%.
Measure: Output voltage at each point.
Dynamic Current Response
Purpose: Test how the charger handles pulsed or rapidly varying current draw (e.g., regenerative braking).
Test: Pulse the load (e.g., ON 50 ms / OFF 50 ms).
Measure:
- Output voltage fluctuation
- CP duty cycle integrity
Acceptance: No protection faults or shutdowns; voltage within transient limits.
Thermal Stability (Soak Test)
Purpose: Determine heating effects during sustained high-current charging.
Test: Apply full rated load for 1–2 hours.
Measure:
- Connector pin temperatures (<50–60°C rise per IEC 62196)
- Cable, housing temperatures
Acceptance: No deformation, melting, or disconnection.
Interruption & Recovery Test
Purpose: Simulate momentary power or load loss and ensure recovery.
Test: Interrupt load or mains supply briefly (e.g., 100 ms).
Observe: Behavior of charger during and after interruption (continue voltage regulation and communication).
Interruption & Recovery Test
Purpose: Simulate momentary power or load loss and ensure recovery.
Test: Interrupt load or mains supply briefly (e.g., 100 ms).
Observe:
- Charger behavior during and after interruption
- Error indication
- Automatic recovery or reset requirement
Fault Injection (Optional but Recommended)
Purpose: Validate fault handling and safety circuits.
Tests:
- Simulate short-circuit or ground fault
- Reverse polarity (for DC guns)
- Overload (e.g., 110% rated current)
Expected Behavior:
- Immediate shutdown or current limit
- No damage to gun or charger
- Proper error reporting
Static Characteristics for Testing of EV Charger Gun Through Load Bank
| Parameter | Test Method | Acceptance Criteria (IEC 61851 / 62196) |
|---|---|---|
| Output Voltage | Measure voltage under constant load | Within ±5% of rated output |
| Output Current | Apply fixed load and measure current | Within ±2% of setpoint |
| Power Output | Voltage × Current at load | Matches rated power (e.g., 3.3kW, 7.4kW) |
| Connector Temperature Rise | After 1 hour at full load (thermal camera or sensor) | < 60°C rise (IEC 62196-1, Cl. 12) |
| Power Factor | Use power analyzer during load | >0.9 typical |
| THD (for AC) | Use harmonic analyzer | < 5–10% (depending on local standards) |
| Insulation Resistance | 500 V DC between live conductors and ground | >1 MΩ (IEC 62196, Cl. 9) |
| Earth Continuity | Measure resistance between PE pin and chassis | < 0.1 ohm |
| No Load Voltage | Measure voltage without EV or load connected | Should be zero or < safety threshold |
| Leakage Current | Measure during charging | <3.5 mA (IEC 60950/60364) |
Example Static Load Test Steps
Rated Load Test
- Apply 100% rated load (e.g., 32 A for AC Type 2)
- Measure voltage, current, and connector temperature every 10 minutes for 1 hour
- Use thermal camera to monitor connector pin temperature
Partial Load Test
- Repeat Rated Load Test for 25%, 50%, and 75% load
- Helps assess power regulation and connector stress at lower loads
Insulation Test
- Disconnect charger from mains
- Apply 500V DC between L/N to Earth
- Measure insulation resistance (Acceptance: >1 MΩ)
Earth Continuity Test
- Measure resistance between PE pin and charger body
- Acceptable: < 0.1 ohm
No Load Test
- Ensure charger does not output voltage when EV is not simulated
- Helps verify CP/PP logic and safety interlocks
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