The subway is indispensable to the development of modern society. With the development of urban population, the increase of vehicles and traffic congestion, the emergence of the subway has facilitated people's travel and saved more time. The subway is built in cities with fast, large capacity and electric traction. metro Run on a fully enclosed line. The subway is basically in the underground tunnel in the urban area. , urban district External linesbasic Located on viaducts or on the ground. In the subway design code, the clock system and the power system are essential.

The clock system provides unified standard time information for subway operation, and provides unified time signals for other systems. The clock system shall consist of a central clock (a master clock SYN4505 standard synchronous clock), a station and a vehicle base clock (two class master clock SYN012 type B timing system) time display unit (sub clock SYN6132 type pointer clock).

The control center sets a primary clock, and the setting of a primary clock satisfies the sharing of multiple lines. All stations and vehicle bases should be equipped with two levels of master clock, central control room, station integrated control room, traction substation duty room, station hall, platform level and other offices directly related to traffic.

The first class master clock receives the standard time signal provided by the reference signal and the synchronous system of the external satellite positioning system; the first class master clock sends the time encoding signal to the two stage master clock regularly to calibrate; the time signal generated by the two stage master clock is transmitted to Zi Zhong. The first class master clock and the two class master clock should be equipped with digital and pointer multiplex output interfaces, and a primary clock should be equipped with data interfaces. The sub clock can be digitally or pointer type, with two sides or one side display according to the use. The working principle is as follows:

Metro power supply should be safe, reliable, energy saving, environmental protection and economical application.The power supply should include external power supply, main transformer substation (or power supply and closing station), traction power supply system, power lighting power supply system, and power monitoring system.

The subway's external power supply plan should be designed according to the urban rail transit network planning, urban power network status and planning, and urban planning. Centralized power supply, decentralized power supply or hybrid power supply can be adopted.

The power supply monitoring system should be set up in the subway power supply system. Its system structure, monitoring objects and functional requirements should be determined according to the characteristics of the power supply system, operation requirements and channel conditions. The power monitoring system should include power dispatching system (main station), substation integrated automation system (sub station) and special data transmission channel connecting main station and sub station.

The function of the power monitoring system should satisfy the unattended operation requirements of the substation. The standard clock signal of the communication system should be adopted in the power monitoring system.The functions of the system include remote control, telecontrol, telemetry, telecontrol, and data transmission and processing, alarm processing and statistical reports, user picture, self checking, maintenance and expansion, information inquiry, safety management, system configuration, on-line monitoring, clock synchronization and so on.

The clock synchronization function plays a very important role in the operation of the subway. The continuous improvement of the clock synchronization function is believed to play a role in all walks of life and improve the safety and efficiency.