Switching Station

TOONICE’s switching station is a key facility in the power system that receives and distributes electrical power without changing the voltage level. Its core function is to control the on-off status of circuits through switchgear, which is equivalent to an extension of the substation busbar.

I. Core Functions and Technical Features

1. Unchanged Voltage Level

The voltage on the incoming side and outgoing side of a switching station is the same. It is commonly seen in 10kV medium-voltage power grids. For instance, it distributes the 10kV electricity output from a substation to multiple surrounding users. Its structure is similar to an “electric power hub”, connecting multiple incoming and outgoing lines via busbars to realize flexible power dispatching.

2. Equipment Composition and Layout

It mainly consists of equipment such as circuit breakers, load switches, busbars, voltage/current transformers, etc. Indoor switching stations need to follow principles like compact layout, natural ventilation, and raised ground (for flood prevention), and be equipped with independent duty rooms. Outdoor ones mostly adopt all-metal enclosed box-type structures (such as RDW-12 intelligent switching stations) to adapt to harsh environments. When arranging equipment, high-voltage cables and control cables are laid separately to reduce electromagnetic interference.

3. Protection and Anti-interference Design

The grounding system is the key to anti-interference. It is necessary to integrate lightning protection grounding, protection grounding, and working grounding to reduce resistance and block interference sources. For example, optimizing the design of the grounding grid can effectively reduce the electromagnetic interference from primary equipment to secondary protection devices and ensure the stable operation of microcomputer-based relay protection systems.

II. The essential difference from substations

III. Application Scenarios and Wiring Modes

1. Urban Power Grid and Industrial Parks

In cities, switching stations can resolve the issue of insufficient outgoing line intervals in substations. For instance, mutual backup of dual power supplies is achieved through “hand-in-hand” loop network wiring, narrowing the power outage range to the vicinity of the fault point. Within industrial parks, switching stations can distribute high-voltage power to multiple workshops, supporting the stable operation of high-load equipment.

2. Railway Power System

Railway switching stations (also called auxiliary sub-section posts) are used for branch control of traction networks. For example, circuit breakers are set up at hub stations to quickly isolate faults when the catenary malfunctions, ensuring the safety of train power supply. In auto-transformer (AT)-fed traction networks, adding switching stations can further reduce voltage loss and the power outage range.

3. Typical Wiring Schemes

① Single-bus sectionalized: Applicable to important users needing dual power supplies (e.g., data centers). When one section of the busbar fails, power supply can be switched to another section via sectionalizing switches.

② Double-bus wiring: Used in load-concentrated areas, supporting flexible dispatching and uninterrupted equipment maintenance during overhauls.

③ Loop network-type wiring: Achieves a loop design through “hand-in-hand” loop networks, with a power supply reliability of over 99.99%, and is the mainstream solution for urban distribution networks.