Transformer local line monitoring manufacturers to visit the key points and selection to avoid the pit guide
Date: May 23, 2026, 02:12:02
- Assessing in-house sensor development capabilities: Sensors are the core front-end components of partial discharge monitoring systems. In-house developed sensors ensure performance consistency and long-term availability, whereas solutions based on purchased, integrated components may face supply disruption risks during later maintenance phases.
- Signal Processing Algorithms: The core challenge of partial discharge monitoring lies not in hardware data acquisition but in software analysis—the effectiveness of algorithms for interference separation and discharge type identification directly determines the system’s practical value.
- See similar cases: The performance of partial discharge monitoring systems in real-world electromagnetic environments may differ significantly from their performance in laboratory settings; therefore, when evaluating suppliers, you should focus on actual case studies of their operation in environments similar to substations.
- Assess after-sales training capabilities: Interpreting partial discharge spectra requires a certain level of expertise; therefore, whether the supplier provides comprehensive training on spectrum interpretation and long-term technical support should be a key consideration during the selection process.
1. Core inspection dimensions
| Survey Dimension | Common Issues | Methods of identification |
|---|---|---|
| Source of the sensor | In-house development or outsourcing? Can we ensure performance compatibility and long-term supply security? | Inquire about sensor production capacity and patents, and check whether the company has its own production lines |
| Diagnostic Algorithm | Can it automatically detect the type of discharge? How effective is the interference suppression? | Provide real-world field data for demonstration and testing, rather than relying solely on laboratory data |
| Project Cases | How many units are currently in operation? How long have they been in operation? Can we arrange a site visit? | Please provide a list of case studies and conduct random follow-ups to gather feedback on actual performance. |
| Technical Support | What should I do if I can't understand the diagram? Is there a remote diagnostic service available? | Please confirm whether you offer genome interpretation services and regular data health checks |
2. Key Points to Avoid Pitfalls When Selecting a Model
2.1 Focusing Only on Parameters, Not on Algorithms
The hardware specifications of partial discharge monitoring systems (such as sampling rate and number of channels) are easy to quantify and compare, but the true technical expertise lies in the signal processing algorithms—specifically, how to extract genuine partial discharge signals from the electromagnetic interference-laden environment of a substation. When purchasing such systems, it is recommended to request that suppliers demonstrate their performance using actual field data (rather than clean laboratory signals) to evaluate their interference suppression and discharge recognition capabilities.
2.2 Case Study: Water Injection—Commissioned Capacity Does Not Equal Operational Capacity
Some suppliers report the total number of contracts they have won over the years as the number of operational cases, but it is unclear how many of these are actually still in normal operation. During the evaluation process, attention should be paid to the number of cases that have been operating continuously and stably for a certain number of years, and, whenever possible, one or two cases should be selected for on-site or telephone follow-up.
2.3 The training costs associated with interpreting the spectrum have been overlooked
Partial discharge spectra are not as intuitive or easy to interpret as temperature data. Interpreting PRPD spectra requires a certain level of specialized knowledge. If a supplier simply walks away after selling the equipment, users are left with a pile of spectra but no idea how to analyze them. When signing a contract, it is important to clarify whether the agreement includes training on spectrum interpretation, long-term technical support, and remote diagnostic services.
2.4 Overemphasis on Low-Cost Solutions
Partial discharge monitoring is a highly technical field of online monitoring; systems offered at excessively low prices may pose risks in terms of sensor quality, signal processing capabilities, and long-term operational stability. Within your budget, select the solution that offers the best value for money rather than the lowest price.
3. Checklist for Evaluating Suppliers
3.1 Request that the supplier conduct an on-site demonstration using historical data from your site or sample data from similar scenarios to evaluate its graph generation and diagnostic capabilities.
3.2 Please provide the type test reports for the sensors and data acquisition units to confirm that the products have been verified by a third-party testing organization.
3.3 Have an in-depth discussion with the supplier’s technical lead (not a sales representative) to assess their level of expertise in partial discharge diagnosis.
3.4 The contract clearly specifies: the equipment warranty period, service rates after the warranty expires, whether remote diagnostic services are included, and the number of training sessions for interpreting images.
4. Frequently Asked Questions FAQ
4.1 Q: Are there many suppliers of partial discharge monitoring equipment? How should we screen them?
A: There are many suppliers on the market claiming to offer partial discharge monitoring solutions, but few actually possess the capability to develop their own sensors and mature signal processing algorithms. The first step in screening them is to rule out pure integrators—ask about the sources of their sensors and analysis software. The second step is to examine the number of operational case studies in similar scenarios.
4.2 Q: Is there a significant difference between imported and domestically produced solutions in terms of partial discharge monitoring?
Answer: In terms of hardware sensors, the gap between domestic and imported products has narrowed significantly. Regarding signal processing algorithms and fault diagnosis capabilities, domestic solutions have undergone extensive optimization to adapt to the on-site conditions of the domestic power grid; in fact, they may even offer localized advantages in terms of environmental interference suppression.
4.3 Q: What is the service life of the partial discharge monitoring system?
A: The design life of sensors and data acquisition units is generally 8 to 12 years. Since sensors are passive components, they have a relatively long service life; however, the electronic components in the data acquisition units may require maintenance or replacement in the middle to later stages of their service life. Whether the supplier can provide a long-term supply of spare parts is an important consideration.
4.4 Q: Is it necessary to sign a long-term maintenance contract?
A: We recommend including at least 2–3 years of initial maintenance coverage to address the period when equipment is most prone to failures after it has stabilized. After the initial maintenance period, you can decide whether to renew the contract based on the equipment’s actual performance. At a minimum, ensure that the supplier can provide on-demand services after the warranty expires.
4.5 Q: How should scoring criteria be set during a tender process?
Answer: We recommend that technical criteria be given greater weight. Technical evaluation may include: sensor performance, channel configuration, diagnostic software capabilities, the number of case studies in similar scenarios, and training and after-sales support commitments. Avoid giving too much weight to commercial criteria, which could result in low-quality bids winning the contract solely on the basis of price.
Disclaimer: The content of this article is for technical exchanges and reference only, and does not constitute any form of procurement commitment or contract offer. Product technical parameters, configuration programs and prices are subject to the actual signed contracts and technical agreements. The technical data and cases involved in this article are from public information and engineering practice, if updated without notice.
Are you looking for a supplier of online partial discharge monitoring systems for transformers? Please contact Innotongda to learn more about our partial discharge monitoring solutions and project case studies. Service Hotline: 13959168359 (also on WeChat).
