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Solutions for Electrical Substation Maintenance

A well-planned electrical substation maintenance program assures a reliable power supply and reduces failures. Many potential issues can be detected during routine substation maintenance activities, such as circuit breaker testing and high voltage testing, reducing the risk of significant plant downtime and preventing future problems. The risk of a catastrophic failure can cost substantial time and money.

Substation maintenance involves periodic planned inspections, checking, testing, and troubleshooting to ensure the correct operation of all components and their interaction throughout the plant lifecycle. Typical inspection and diagnosis processes include transformers, breakers, protection relays, wiring, and general switchgear. Key procedures like circuit breaker testing utilize advanced equipment such as primary injection test sets and secondary injection test sets to validate performance under fault conditions.

Each device requires different strategies. Implementing the right action at the right time defines various substation maintenance procedures, whether time-based, condition-based, or reliability-based. All of them must be supported by suitable testing tools. Using precise instruments like relay testers ensures that protection relays function correctly, further enhancing the reliability of the electrical substation.

Description

Additional Information about electrical substation maintenance

Primary testing in the electrical substation maintenance

Considering cost and the impact of failures, the most critical components in substation maintenance are power transformers and circuit breakers. Many old transformers and breakers remain in use with aging problems that require periodic electrical substation maintenance. One of the best practices in this field is circuit breaker testing. Periodically analyzing their physical and electrical parameters helps predict abnormal operations before they happen. Commonly checked parameters include open/close timing, pole synchronism, contact resistance, and coil condition, as well as DC battery status and motion analysis. The small and user-friendly SMC PME-500-TR includes all the functions required in electrical substation maintenance plans and reduces the testing time to evaluate the condition of the breaker.

Measuring breaker contact resistance and the integrity of other interconnections is common practice in substation maintenance routines. Our new PRIME micro-ohmmeter is best suited for this application, performing both static and dynamic resistance measurements. This is essential for assessing the actual condition of contacts in inaccessible SF₆ or vacuum chambers.

Power transformers are also critical during electrical substation maintenance. Their failure can lead to significant economic losses. Exposed to various electrical and thermal stresses over their lifetime, transformers require many routine tests that are included in substation maintenance programs. These tests often involve high voltage testing to assess insulation integrity and performance under stress.

Apart from testing each device separately, it is essential to test the entire protection circuit periodically—or after any system modification—to ensure the integrity of the total circuit. The protection system can be tested as a whole by injecting primary test currents using a primary injection test set. The combination of mobility, digital regulation, and versatility makes the RAPTOR the ideal system for all primary injection testing required in electrical substation maintenance routines.

Current transformer testing is also an important part of substation maintenance. Protective relays can only operate adequately if they receive the correct secondary current from the CTs. Using advanced equipment like the RAPTOR, which includes functionalities for current, voltage, and power transformer testing—as well as circuit breaker testing and switchgear testing, ground grid, and step & touch measurements—ensures comprehensive maintenance. Incorporating tools like primary injection test sets and performing high voltage testing enhances the reliability and safety of your electrical substation.

Secondary testing in the electrical substation maintenance.

Periodic testing is essential in substation maintenance to ensure that a protection scheme provides satisfactory performance for many years after installation. Secondary injection tests may be carried out at suitable intervals to check relays, protection panels, wiring, and all secondary equipment performance during the electrical substation maintenance planning or after any modification. Using advanced relay testers during these procedures enhances the accuracy and reliability of the tests.

The type and frequency of testing required will depend on the type and technology of the protection installed. Secondary injection may involve testing of overcurrent, distance, differential, voltage, and frequency protections, reclose schemes, IEC 61850 compliance, etc., apart from checking all secondary control and protection circuits, wiring, polarity, burden, etc. Additionally, circuit breaker testing and high voltage testing are critical components of comprehensive substation maintenance, ensuring that equipment can handle operating conditions and fault scenarios.

SMC offers the widest range of secondary injection test sets, both single and 3-phase, to accomplish any secondary testing work during substation maintenance (PTE-100-C series, PTE Range, MENTOR 12, etc.), along with a full range of accessories and must-have tools for every need (PME-20-PH, PTE-30-CH, etc). Our advanced relay testers and equipment for circuit breaker testing and high voltage testing ensure that all aspects of your substation’s protective systems are thoroughly evaluated. As usual with SMC test equipment, simplicity and ease of use are common to all secondary testing solutions for substation maintenance.

For more information, please check the related SMC products.