I. Industry Background: The Hidden Threat of Inrush Currents to New Energy Power Supply Equipment

With the rapid proliferation of charging infrastructure for new-energy vehicles, electric-vehicle power supply equipment faces complex grid conditions and frequent load switching during actual operation. At the moment the contactor closes, the system can generate surge currents as high as several hundred amperes; this short‑duration… High strength Current surges of a certain magnitude can damage internal components of power‑supply equipment, disable protective circuits, and even trigger safety incidents. However, the industry has yet to reach a unified technical consensus on methods for evaluating surge‑withstand capability; test‑equipment accuracy requirements and the degree of standardization in testing procedures vary widely, creating potential risks in quality control prior to shipment.

Against this backdrop, ZHONGJIA EQUIPMENT, leveraging years of technical expertise in electrical performance testing, has developed an impulse current tester that meets international standards, providing the industry with a quantifiable and reproducible solution for assessing surge withstand capability. Designed in strict accordance with international standards such as IEC 61851-1:2017-02, Clause 12.2.6, and ISO 17409:2015, Clause 8.2.2, this equipment can accurately simulate surge impact scenarios experienced by power supply devices under real-world operating conditions, helping manufacturers identify potential risks during design verification and factory acceptance testing.

II. Authoritative Interpretation: Technical Principles and Parameter Design for Surge Withstand Capability Testing

2.1 Physical Characteristics and Hazard Mechanisms of Inrush Currents

Inrush current refers to the brief, high‑peak current that occurs when an electrical device is first energized. In electric‑vehicle power supply systems, this phenomenon typically arises after a contactor closes, as capacitors charge, transformers magnetize, or loads undergo sudden changes; under such conditions, the system may experience current surges far exceeding its rated value within 100 microseconds. According to international standards, a compliant power supply must withstand a peak current of 230 amperes for 100 microseconds and maintain an RMS current of 30 amperes for the subsequent second, without triggering unintended tripping of protective circuits or degrading component performance.

2.2 Engineering-Based Logic for Setting Test Parameters

During the development of its impulse current testing machine, Zhongjia Testing Equipment Technology has translated the theoretical requirements of international standards into a practical engineering parameter system. The equipment is equipped with a single-phase 220-volt power supply and is capable of… Independence The external sample voltage is regulated to the standard single-phase 220 V, ensuring that the test environment accurately reflects real-world operating conditions. For current parameter design, the system is preconfigured with a peak current output capability of 230 A, and, in conjunction with a high-precision current sensor, it can achieve response within 100 microseconds after power interruption. Precision Measurement: The selection of this measurement window is based on the physical characteristics of the surge current decay curve—the duration of the peak current determines the extent of thermal stress accumulation in the component.

The equipment employs a control architecture integrating a PLC with a touch screen. Operators can use the human–machine interface to pre‑set test voltage and current thresholds, as well as trigger timing, enabling automated closed-loop control throughout the testing process. This design not only minimizes human‑induced operational errors but also leverages a data‑logging function to comprehensively record each test’s current waveform, peak occurrence, and duration, thereby providing robust data support for product optimization and batch‑to‑batch comparisons.

2.3 Analysis of Compliance with Test Method Standards

This test machine's Core The value lies in transforming the descriptive technical requirements of IEC 61851‑1 into repeatable, executable test procedures. While the standard specifies that supply equipment must withstand a “230‑ampere peak for 100 microseconds,” it does not define critical engineering details such as the power source’s internal impedance, trigger accuracy, or measurement bandwidth. Zhongjia Testing’s solution ensures consistent test conditions through power‑system impedance matching, high‑speed data acquisition cards, and microsecond‑level timing control. Additionally, the equipment is equipped with a communication interface to enable integration with data management systems, thereby meeting manufacturers’ compliance requirements for test‑data traceability.

III. Industry Insights: Development Trends and Application Boundaries of Surge Testing Technology

3.1 The Evolutionary Direction of Testing Standards

In recent years, the International Electrotechnical Commission has continuously updated the safety standards for electric vehicle charging equipment, with surge withstand capability testing now from… most Initial qualitative descriptions are gradually evolving toward quantification and digitalization. In the future, standards may further refine surge‑parameter thresholds for equipment across different power levels and introduce additional requirements for assessing resistance to repetitive surges. This implies that test equipment must be capable of simulating multiple operating conditions and conducting long‑term reliability verification—such as subjecting components to thousands of consecutive surge events to evaluate their fatigue life.

3.2 Extended Application Scenarios of Testing Technologies

In addition to power‑supply equipment for new‑energy vehicles, surge‑withstand testing is expanding into areas such as energy‑storage systems, photovoltaic inverters, and industrial power supplies. These application scenarios impose differentiated requirements on test equipment regarding voltage levels, current waveform types, and measurement accuracy. Through a modular design approach, Zhongjia Testing Equipment Technology enables its test platforms to adapt parameter configurations to meet the specific standards of various industries—for example, by extending the peak‑current range up to 500 amperes to accommodate the high‑power applications of energy‑storage systems.

3.3 Reconstructing the Value of Digital Testing

Traditional surge testing relies on manual reading of oscilloscope waveforms and manual data recording, which is inefficient and prone to errors. Zhongjia Testing’s solution integrates automated data acquisition, waveform analysis, and report generation; test results can be directly imported into the enterprise quality management system, enabling closed-loop management from testing to continuous improvement. This digital transformation not only boosts testing efficiency but also lays the foundation for building a product‑performance database. By mining and analyzing historical data, manufacturers can identify design weaknesses and optimize component selection.

IV. Corporate Value: Advancing the Standardization of Industry Testing Technologies

ZHONGJIA EQUIPMENT has accumulated extensive engineering experience in the field of charging connectors and power supply equipment testing. The surge current tester developed by the company not only meets the technical requirements of international standards but also, through automated control, data traceability, and modular scalability, provides power supply equipment manufacturers with a comprehensive surge protection verification solution. This equipment has been deployed in the product development and quality control processes of numerous new-energy enterprises, helping customers shorten testing cycles and enhance product reliability.

From the perspective of industry collaboration, Zhongjia Testing’s technical solution offers a practical, engineering‑oriented roadmap for the standardized implementation of surge testing for power supply equipment. By translating the technical specifications outlined in the standard into executable test procedures, it lowers the technical barriers to compliance for small and medium-sized enterprises. Moreover, the equipment’s data‑interface design enables data sharing with third‑party testing organizations, paving the way for the establishment of a unified industry‑wide test database.

V. Recommendations for the Industry

For power‑supply equipment manufacturers, it is recommended to incorporate surge‑withstand capability simulation and analysis during the product design phase, followed by testing to verify that the design margins meet real‑world application requirements. In the manufacturing process, a batch‑sampling inspection regime should be established to ensure that component‑to‑component variations do not compromise the product’s surge‑tolerance performance. For testing laboratories and standards‑development organizations, efforts should be made to refine and enhance the practicality of surge‑testing methods, clearly defining calibration requirements for test equipment and establishing criteria for controlling measurement uncertainty.

As the charging power of new‑energy vehicles advances to higher levels, the peak values and energy densities of inrush currents will continue to increase, necessitating corresponding upgrades in testing technologies. All stakeholders in the industry should strengthen the sharing and analysis of test data, establish a database of typical failure modes, and provide empirical evidence to support equipment design optimization and standard revisions. Only through precise testing methods and rigorous quality control can the long‑term reliable operation of power‑supply equipment in complex grid environments be ensured.