配电设备入门与选型指南

From the grid to the load: how the equipment works together

This simplified path shows how switchgear, transformers and low-voltage distribution connect the medium-voltage network to local loads.

Medium-Voltage Distribution Network
01

MV Switchgear / Ring Main Unit

Connects the incoming supply, switches feeders, applies protection and isolates faulted sections.

02

Transformer

Steps voltage down for local distribution; in generation and renewable projects, it may also perform the step-up duty.

03

LV Switchgear & Distribution

Receives the transformed supply, protects outgoing circuits and distributes power to local loads.

Industrial, Commercial & Infrastructure Loads

从这里开始：设备基础

如果你对配电完全陌生，先看完整系统地图，再按设备类别学习构造、工作原理、型号差异和使用寿命。

01零基础认识配电设备跟着电能从电网走到负载，并分清电压、电流、容量、功率和用电量。 02变压器怎样工作认识铁芯、绕组、绝缘和冷却，再理解不同容量与结构为什么用途不同。 03开关柜与环网柜怎样工作分清断路器、开关、熔断器、母线和继电保护，并理解环网柜的位置。 04箱式变电站里面有什么顺着中压、变压器和低压单元看完整电能路径，了解配置如何改变用途。

Choose a Selection Guide

Choose the equipment family first, then confirm its ratings, construction and project-specific configuration.

01

Compact Substation Selection Guide

Define the incoming system, transformer duty and outgoing distribution before comparing prefabricated and pad-mounted configurations.

  • System voltage, total load and outgoing circuits
  • MV unit, transformer and LV unit arrangement
  • Enclosure, ventilation, foundation and cable entry
Open Selection Guide
02

Transformer Selection Guide

Choose the transformer by its system duty, then compare construction, voltage class and application requirements.

  • HV and LV voltage, capacity and frequency
  • Oil-immersed or dry-type construction
  • Vector group, taps, impedance and accessories
Open Selection Guide
03

Switchgear & RMU Selection Guide

Start with the switching and protection duty, then confirm the rated current, short-circuit level, feeder arrangement and operating method.

  • Rated voltage, current, fault level and circuits
  • Fixed, withdrawable, gas or solid-insulated construction
  • Protection, interlocking, operation and maintenance
Open Selection Guide

Transformer Knowledge Guides

Use these guides for transformer sizing, vector groups, factory tests, pre-energization checks and lifecycle-cost comparison.

01How to Size a Distribution TransformerBuild a defensible kVA estimate from connected load, demand, motor starting and future allowance. 02Transformer Vector Groups ExplainedRead clock notation and understand why phase displacement, neutral and system compatibility matter. 03Transformer FAT and Test ReportsSeparate routine, type and special tests, then review the records supplied for the actual unit. 04Pre-Energization Inspection ChecklistCheck receipt, storage, installation, earthing, insulation and protection before first energization. 05Transformer Losses and Lifecycle CostCompare purchase price with no-load loss, load loss, duty cycle and expected operating years.

Project Information Checklist

Send any available project information; we will identify any additional technical details needed to review the configuration.

Upload Project Requirements ›
Single-line diagramExisting SLD or a simple system sketch.
Application and system roleUtility, industrial, commercial or renewable-energy duty.
Voltage and frequencyIncoming, outgoing and local system frequency.
Capacity or connected loadRequired rating, load schedule or feeder demand.
Destination and standardsCountry, applicable specification and approval needs.
Installation environmentIndoor or outdoor, temperature, altitude and protection needs.
Required project documentsDrawings, datasheets, test records, FAT scope and handover files.