The Solution for Efficient Commissioning of Medium-Voltage Switchgears

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Renewable sources like wind power and photovoltaics, along with the rise of electromobility, are pushing medium-voltage grids to their limits. Advanced protection concepts and flawlessly functioning protection systems are crucial to prevent equipment damage and to ensure safety.

And, while renewable energy is reshaping the energy sector, the groundbreaking CMC 500, an unparalleled testing solution, enters the market to revolutionize the commissioning process.

Unlike conventional methods that demand considerable time and multiple devices, this test set allows to streamline the commissioning process of medium-voltage switchgears with its modular, multi-phase design. It sets a new benchmark in efficiency, reducing testing time by up to 80% while ensuring comprehensive validation of protection systems.

The grid’s transformation

Network operators are aware of the new requirements, and investments in the distribution networks have already increased significantly. At the medium-voltage level, this concerns the modernization and adaption of existing grids. 

Another important step is further expansion: developing the necessary infrastructure for merging energy from large clusters in the photovoltaics and wind power sectors. In both cases, a considerable part of the investment concerns the commissioning and regular maintenance of the equipment as well. Testing all these new assets is extremely difficult due to the shortage of new talent.

Why is the CMC 500 a gamechanger in the field? On one hand, the test set enables faster commissioning, leading to reduced costs and on the other hand, the connected software and control interface are straightforward and designed with simplicity in mind, minimizing the learning curve for beginners. Many of its operations can be automated and come with guided workflows, ensuring that even less experienced users can perform complex tasks with confidence.

Comprehensive testing of medium-voltage switchgears

Commissioning and maintenance of medium-voltage switchgear involves a vast number of tests on a range of different types of equipment. If the equipment is highly complex, – which is true for most intelligent substations – the tool for testing should be versatile and straightforward. The benefit of using just one such test set is clear: reduced preparation time and consistent results.

To explore the versatility of the CMC 500, let’s see how this solution covers almost every phase of the commissioning process.

1. The first step of modern protection relay testing is the wiring check. To ensure efficient commissioning, wiring checks with a polarity checker are mandatory. Avoiding wiring problems ensures the accuracy of test results.
   This step also involves measuring the transducers. This measurement is possible with a brief current injection on the primary side of the device. Ensuring safety during this process is of utmost importance. Next to following the five safety rules, the CMC 500 provides several features that reduce electrical hazards, for instance clear operational status indicators, and an interlock key that prevents accidental activation.
2. The second step focuses on testing the protection relays and checking if the correct parameters are in place. With a variety of test templates, the CMC 500 allows to automate individual steps or even the entire test procedure. Defining test procedures in advance makes maintenance easy as the templates are re-usable time and time again. On top of that, a key benefit is a fully automatic documentation of test results.
   In relation to the overall investment and the operation of a substation, the described process enhancements can result in up to 80 percent time savings.
3. Once correct functioning of the protection relays has been confirmed, the connection to the process control can be verified. Correct assignment is verified by stimulation of the process control, what is easily done with the CMC 500 by injecting the necessary signals. 
4. The next step is to verify whether the circuit breaker is correctly connected and controlled. This includes using a live trip to determine switching times. Maintenance can involve additional measurements, such as switching pole synchronism, motor current, and coil current. A versatile protection test set, with appropriate hardware and software, is the ideal solution for these tasks. Moreover, such a testing solution can eliminate the need for multiple separate testing devices.
5. Troubleshooting during commissioning can present an additional challenge. By using the CMC 500, technicians quickly get a clear understanding of issues and can efficiently identify the source of the fault. Its applications include:

• Measurement of inrush currents on transformers and motors
• Recording of steady-state or transient analog and binary signals for troubleshooting
• Comparison of analog signals for verification of performance
• Simultaneous injection and measurement with a single test set.

Ultimately, the device’s versatility is demonstrated by its ability to deliver accurate and efficient testing of analog, hybrid, and fully digital systems. Furthermore, it can seamlessly integrate essential network protocols for medium voltage grids like GOOSE and client/server (MMS).

The above list clearly shows that a multifunctional protection test set provides the flexibility needed to take control of the growing number of testing tasks in medium-voltage grids.

Requirements for the protection test set and the testing software

While a flexible hardware platform is a precondition for versatile use, the appropriate software modules are also needed to unlock the full potential. The CMC 500 is built on a robust hardware platform that establishes a solid basis for the device’s multi-functional use, including:

• Powerful current and voltage outputs
• Binary and analog inputs and outputs
• An IEC-61850 interface.

The comprehensive software solution Test Universe enables a high degree of automation of testing and documentation, leading to substantial efficiency gains. Using the available modules, commissioning teams can streamline the testing process, verify system performance accurately, and significantly accelerate the commissioning phase.

Considerable advantages of multifunctionality 

A main advantage of multifunctionality is that protection engineers only need to carry a single test set that also allows them to switch between equipment seamlessly. This eliminates the need for multiple setups and the usage of different hardware and software at every step of the process.

However, from a company’s perspective, other advantages also come into play:

• With fewer variations of test sets, training costs drop.
• Maintenance management of test sets gets easier as there are fewer interfaces, processes, and contacts needed.
• Fewer test sets simplify test template management: a versatile test set stores all equipment templates in one library, enabling one-click use and improved testing efficiency and quality.
• Documentation for various equipment tests is generated in a single software, eliminating manual consolidation and formatting, thus saving time.
• If a versatile test set satisfies the necessary requirements, purchasing one device can offer lower overall costs.

When less is more

Advancements in technology enabled the development of the CMC 500, a versatile protection testing solution that covers a wide range of applications. It not only makes day-to-day testing easier for protection engineers but also reduces expenses in the middle and long term at company level. Due to the Protection Testing Library (PTL), creating a uniform basis and reducing the administrative load is a significant improvement.

These advantages are particularly evident when commissioning medium-voltage switchgear. In this sector, future-proof, versatile protection test sets have the potential to alleviate upcoming challenges. Choosing the CMC 500 means having a reliable, more efficient, and secure tool that saves considerable time, thus freeing up capacity for the work force.