Uninterruptible power supply equipment quality appraisal

Uninterruptible power supply equipment (UPS) takes power electronic conversion technology as the core and provides stable power for key equipment through rectification, energy storage, inverter and other modules. It is widely used in data centers, medical systems, industrial control and other fields that require extremely high power supply continuity. In data centers, it ensures the continuous operation of servers and network equipment; in medical scenarios, it maintains power stability for surgical equipment and life support systems; in industrial manufacturing, it protects precision machine tools from voltage fluctuations. Compared with traditional power supply methods, UPS has features such as fast switching, harmonic suppression, and intelligent management. It is the core equipment to ensure the safe operation of critical infrastructure.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide uninterruptible power supply equipment quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for uninterruptible power supply equipment quality appraisal.

As the application scenarios of uninterruptible power supply equipment become more complicated, quality dispute cases are gradually increasing. The judicial dispute focuses on:

1, performance index dispute: whether the actual efficiency reaches the standard and whether the conversion time exceeds the limit;

2, material and process defects: battery capacity decays too fast, IGBT Insufficient module heat dissipation design leads to overheating;

3. Control system failure: unreasonable overload protection threshold setting, battery management system failure;

4. Contract performance issues: the delivery of UPS does not comply with the technical agreement.

uninterruptible power supply equipment quality identification technical methods include:

1, material performance testing

using a spectrometer to detect pick material and verify the heat treatment process; detect internal defects in the frame welds through ultrasonic flaw detection, and evaluate surface cracks using magnetic particle testing (MT).

2, geometric accuracy verification

The laser interferometer measures the positioning accuracy of the cutting head (±0.05mm) and the straightness of the guide rail (≤0.02mm/m); the three-coordinate measurement of the cutterhead tooth seat spacing verifies the consistency with the design drawings (such as deviation ≤±0.1mm).

0 Scanning electron microscope (SEM) was used to observe the fracture morphology of the main bearing, and energy dispersive spectrometer (EDS) was used to detect the migration of wear elements; the cutterhead stress distribution was analyzed based on finite element simulation, and the structural design was optimized.

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A data center of the applicant signed a "Modular UPS Procurement Contract" with a power supply company of the respondent, agreeing to purchase 5 sets of 200kVA power frequency UPS for server power supply. After half a year of operation, the UPS frequently experienced battery alarms and was unable to switch to inverter mode when the mains power was interrupted, causing the server to shut down. The data center believed that UPS had quality defects and demanded compensation for losses. The power company argued that the problem was caused by improper maintenance of the battery, and both parties went to court.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of "uninterruptible power supply equipment", contract technical agreements, on-site investigation case materials and other data, and made the following quality analysis opinions:

The battery plate thickness of the uninterruptible power supply equipment involved in the case is only 2.5mm (contract requirement 3.0mm), and the capacity is only 120Ah (nominally 150Ah); the battery pack parallel cable cross-sectional area is insufficient (designed 35mm², actual measured 25mm²), and the internal resistance increases by 20%; there is a weak weld in the control board welding (X-ray inspection shows a defect rate of 5%), leading to BMS misjudgment.

The power supply company failed to provide batteries of specified thickness and copper-aluminum composite heat sinks according to the contract. Process defects caused BMS failure, which was the main reason for equipment problems.

Uninterruptible power supply equipment quality appraisal report should include the following content:

1. The purpose and basis of the appraisal.

2. Model, specification, manufacturer and other information of the equipment being identified.

3. Identification method.

4. Identification results (including whether there are quality problems, causes of problems, etc.).