パフォーマンス-パラメータに与える影響コスト

Performance Parameters and Their Impact on Cost 1. Short-Circuit Impedance The short-circuit impedance affects the voltage regulation and reactive power losses of transformers. A higher short-circuit impedance improves voltage regulation but results in a larger short-circuit current magnitude, influencing the power grid and system. For shell-type transformers, the presence of the winding’s ampere-turns allows some flexibility in short-circuit impedance without significant cost changes. 2. Load Losses Load losses include DC resistance losses, eddy current losses in conductors, circulating current losses between parallel conductors, and stray losses in structural components. (1) DC Resistance Losses: Increasing the cross-sectional area of conductors to reduce DC resistance losses increases the winding’s volume and conductor length,

Power transformers can be classified into two types based on their structure: core-type transformers and shell-type transformers. 1. Core-Type Transformers: The winding of a core-type power transformer is cylindrical, and the cross-section of the core column is approximately cylindrical. The high-voltage and low-voltage windings are concentrically arranged, and the body (core and winding) is vertically oriented. The winding structure can take various forms, such as circular, helical, continuous, layered, twisted, and internal shielded, depending on the voltage and current. The core column is approximately cylindrical in cross-section, and the shape of the yoke varies based on the design. 2. Shell-Type Transformers: The winding of a shell-type transformer is flat rectangular,

The principle of operation for a sliding core transformer is based on the concept of “sliding.” The transformer consists of two coils, one of which is connected to the primary side, and the other to the secondary side. The coils are separated by a ferrite core, which is affixed to a moveable arm. The arm is moved across the coils, changing the inductance of each coil. This results in a change in the output voltage of the transformer. The arm is moved by a voltage regulator or control circuit, which is connected to the primary and secondary sides of the transformer. When the voltage is increased on the primary side,

Vacuum epoxy casting technology has been widely used in the production of transformers, as it offers a range of advantages in terms of performance, safety and cost. However, it is also important to consider the environmental benefits of this technology, which are becoming increasingly important in the modern world. This article will discuss the environmental benefits of vacuum epoxy casting transformers. First, vacuum epoxy casting technology reduces the need for toxic chemicals in the production process. Traditional transformers often require the use of hazardous substances such as lead, sulfuric acid and mercury. By using vacuum epoxy casting technology, these chemicals can be eliminated from the production process. This reduces the

How to Approach Transformer Temperature Rise Reasonably? Perspectives on temperature rise encompass various aspects essential for the long-term stable operation of transformers, specifically in the following dimensions: (1) Safety: The prudent control of temperature rise aims to ensure that the internal temperature of the transformer does not exceed safety limits. This measure is primarily intended to mitigate the risk of overheating, effectively preventing potential fire incidents or other malfunctions. (2) Efficiency: Careful temperature rise control contributes to improving the efficiency of transformers. During the design phase, the emphasis is typically on achieving the lowest possible temperature rise to reduce energy wastage and enhance overall energy efficiency. This ensures that transformers

What is the thermal class of a transformer? The thermal class of a transformer typically refers to the thermal stability of its insulation system, a crucial factor directly impacting the temperature endurance during prolonged operation. This classification is commonly denoted by letters such as A, E, B, F, H, each representing a specific maximum temperature level. In the design process of transformers, careful consideration is given to selecting an appropriate thermal class to ensure the transformer maintains excellent performance and reliability under normal operating conditions. Opting for a higher thermal class can enhance the transformer’s load-carrying capacity, but it may also result in increased manufacturing costs. Therefore, a balanced consideration

How is the impulse voltage test conducted for transformers? The impulse voltage test comprises lightning impulse tests (including full-wave and chopped-wave tests) and operating wave impulse tests. In the latest IEC76-3 standard, for transformers with a rated voltage (U) ≤ 40.5kV, both full-wave and chopped-wave impulse tests are considered type tests. For transformers with U ≥ 72.5kV, the full-wave impulse test is a routine test, while the chopped-wave impulse test is a type test. Transformers with U ≥ 252kV undergo routine tests for full-wave, chopped-wave, and operating wave impulse tests. The full-wave and chopped-wave impulse tests are alternately conducted, typically with negative polarity. It starts with one full-wave impulse, followed

Maintenance and Fastening of Transformer Body 1. Body Cleaning: Users and manufacturers of transformers have stringent requirements for the cleanliness of the transformer body, making body cleaning crucial. During the assembly process, crucial components, especially insulating parts, require meticulous cleaning. Typically, a vacuum cleaner is used, and clean white cloths are employed for wiping. In cases of oil contamination, the face adhesive method is the simplest and most effective approach. The cleaning outcome necessitates that metallic foreign objects, particularly non-metallic ones, remain invisible. 2. Body Fastening: (1) Re-fasten the upper and lower iron yoke screws and baseplates, ensuring proper placement of washers when tightening bolts and nuts. (2) When fastening the strap

How is the Induced Voltage Withstand Test for Transformers conducted? The Induced Voltage Withstand Test for fully insulated transformers is conducted by opening the high-voltage winding and applying twice the rated voltage at a frequency of 100-250Hz to the low-voltage winding. Due to the higher frequency, the iron core can ensure twice the induced voltage when unsaturated, thereby testing the insulation performance of winding-to-winding, layer-to-layer, and phase-to-phase. This evaluates the longitudinal insulation level of the transformer. For transformers with graded insulation, raising the neutral point voltage (supporting it) allows the assessment of the main insulation level. Consequently, the Induced Voltage Withstand Test not only tests the longitudinal insulation but also

How to Look at TheParallelOperation of Transformers？ The parallel operation of transformers refers to connecting the primary windings of two or more transformers to a common busbar and connecting their secondary windings to a common secondary busbar. Transformers operated in this manner are termed to be in parallel operation. 1. Advantages of parallel operation of transformers include: (1) Meeting Demands of Large Power Grids: Addresses the capacity requirements that a single transformer may find challenging to meet in a large power grid. (2) Enhancing Power Supply Reliability: Improves the reliability of power supply; if one transformer experiences a fault and is disconnected, others can continue supplying power. (3) Adjusting Transformer Quantity Based