Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

What lightning protection measures are used for H61 distribution transformers?A surge arrester should be installed on the high-voltage side of the H61 distribution transformer. According to SDJ7–79 "Technical Code for Design of Overvoltage Protection of Electric Power Equipment," the high-voltage side of an H61 distribution transformer should generally be protected by a surge arrester. The grounding conductor of the arrester, the neutral point on the low-voltage side of the transformer, and the

Measures to Prevent H59 Oil Immersed Power Distribution Transformer from Burning OutIn power systems, H59 Oil Immersed Power Distribution Transformer play an extremely critical role. Once burned out, they can cause widespread power outages, directly or indirectly affecting the production and daily lives of a large number of electricity users. Based on the analysis of multiple transformer burnout incidents, the author believes that a considerable number of such failures could have been avoided or

H61 Distribution Transformer Selection includes the selection of transformer capacity, model type, and installation location.1.Selection of H61 Distribution Transformer CapacityThe capacity of H61 distribution transformers should be selected based on the current conditions and development trends of the area. If the capacity is too large, it results in the “large horse pulling a small cart” phenomenon—low transformer utilization and increased no-load losses. If the capacity is too small, the tran

How to Implement Transformer Neutral Grounding Gap Protection Measures?In a certain power grid, when a single-phase ground fault occurs on a power supply line, both the transformer neutral grounding gap protection and the power supply line protection operate simultaneously, causing an outage of an otherwise healthy transformer. The main reason is that during a system single-phase ground fault, the zero-sequence overvoltage causes the transformer neutral grounding gap to break down. The resulting

1.Innovative Winding Structures for 10 kV-Class High-Voltage High-Frequency Transformers1.1 Zoned and Partially Potted Ventilated Structure Two U-shaped ferrite cores are mated to form a magnetic core unit, or further assembled into series/series-parallel core modules. Primary and secondary bobbins are mounted on the left and right straight legs of the core, respectively, with the core mating plane serving as the boundary layer. Windings of the same type are grouped on the same side. Litz wire i

1. System Configuration and Operating ConditionsThe main transformers at Zhengzhou Rail Transit’s Convention & Exhibition Center Main Substation and Municipal Stadium Main Substation adopt a star/delta winding connection with a non-grounded neutral point operation mode. On the 35 kV bus side, a Zigzag grounding transformer is used, connected to ground through a low-value resistor, and also supplies station service loads. When a single-phase ground short-circuit fault occurs on a line, a path

The grounding disconnect switch of a pad-mounted transformer is a switching device used to isolate the pad-mounted transformer from the grounding cable. It is an essential component of pad-mounted transformer equipment and plays a critical role in protecting the safety of the transformer equipment. The grounding disconnect switch of a pad-mounted transformer serves important functions in grounding down leads, grounding switching, auxiliary grounding, and lightning protection.Its functions includ

Grounding transformers, commonly referred to as "grounding transformers" or simply "grounding units," operate under no-load conditions during normal grid operation and experience overload during short-circuit faults. Based on the filling medium, they are commonly categorized into oil-immersed and dry-type types; based on phase count, they can be either three-phase or single-phase grounding transformers.A grounding transformer artificially creates a neutral point for connecting a grounding resist

In power systems, transformers, as core equipment, are critical to the safe operation of the entire grid. However, due to various reasons, transformers are often exposed to multiple threats. In such cases, the importance of grounding resistor cabinets becomes evident, as they provide indispensable protection for transformers.Firstly, grounding resistor cabinets can effectively protect transformers from lightning strikes. The instantaneous high voltage caused by lightning can severely damage tran

Problems with Zero-Sequence Protection of 110 kV TransformersIn an effectively grounded system, the neutral-to-ground displacement voltage of a transformer is limited to a certain level, and the neutral-point gap protection does not operate. The purpose of installing gap protection is to prevent damage to transformer insulation caused by elevated zero-sequence voltage in non-effectively grounded systems. The discharge gap only operates when a single-phase ground fault occurs, all directly ground