I. Electrical Performance Stability Test

1. Output Voltage Stability

Measures the device's ability to maintain a stable output voltage under different load and input fluctuation conditions. Common indicators:

• Steady-state voltage deviation ≤ ±2%

• Dynamic response time ≤ 20ms

2. Output Frequency Stability

Especially suitable for off-grid or microgrid scenarios, requiring frequency stability:

• Deviation generally required ≤ ±0.1Hz

3. Total Harmonic Distortion (THD)

A core indicator of the quality of output alternating current, directly affecting the operation of precision equipment.

Industry high-quality standard: THD ≤ 3%

II. Environmental Adaptability Stability Test

1. High and Low Temperature Operation Test

Tests the device's ability to operate stably under extreme climates:

• Operating temperature range: −20°C ~ +60°C

• High-temperature full-load operation ≥ 8 hours without derating

2. Damp Heat Test

Simulates operational stability in high-humidity environments:

• Continuous operation at 95% humidity for 48 hours without abnormality

3. Salt Spray and Corrosion Test (Outdoor Equipment)

Ensures long-term reliable operation in harsh environments such as coastal areas and chemical industrial zones.

III. Load Adaptability and Impact Test

1. Load Sudden Change Test

Simulates instantaneous load changes in actual power consumption scenarios:

• 0% → 100% load switching without shutdown

• Stabilization recovery time ≤ 50ms

2. Impact Load Capacity

Tests the instantaneous bearing capacity during the start-up of motors, air conditioners, pumps and other equipment:

• Instantaneous overload capacity ≥ 200% (lasting 3–5 seconds)

IV. Verification of Protection Function Stability

The reliability of the inverter-controller all-in-one system is reflected not only in normal operation, but also in the response speed and accuracy of protection under abnormal conditions.

Key protection tests include:

• Overvoltage protection trigger accuracy

• Overcurrent protection response time

• Short-circuit protection action time

• Consistency of over-temperature protection threshold

• Effectiveness of reverse connection protection

Requirements for high-quality equipment: Protection actions are free of misjudgment, no delay, and no crash.

V. Long-Term Reliability Test (Life Category)

1. Burn-in Test

Continuous full-load operation test:

• ≥ 72 hours of uninterrupted operation

2. MTBF Test (Mean Time Between Failures)

Generally required for industrial-grade equipment:

• ≥ 100,000 hours

3. Start-Stop Cycle Test

Simulates long-term service environment:

• ≥ 5000 start-stop cycles without abnormality

VI. System-Level Stability Test (Integrated Machine Linkage)

Different from a single inverter, the inverter-controller all-in-one system includes a control module, MPPT module, communication module, and protection circuit, so system-level verification is also required:

• Stability of multi-module coordinated operation

• Communication continuity test (RS485 / CAN / WiFi)

• Parallel operation stability test

• Battery management compatibility test

VII. EMC and Safety Stability

1. Electromagnetic Compatibility (EMC) Test

Ensures that the device will not interfere with other electronic equipment and has anti-interference capabilities.

2. Safety Standard Test

Including insulation strength, leakage current, grounding continuity, etc., which are directly related to the safety of personnel and equipment.

The stability of the inverter-controller all-in-one system is not a single indicator, but a comprehensive performance system composed of electrical performance, environmental adaptability, load capacity, protection mechanism, life reliability, and system coordination capability. Only products verified through full-dimensional tests can achieve long-term stable operation in actual projects.

For engineering contractors and purchasers, when evaluating the quality of inverter-controller all-in-one systems, priority should be given to:

Whether it has a complete test report + whether it has been verified under real working conditions + whether it meets international standard certification

These three points can often reflect the real reliability of the equipment more than simple parameters.