What is the concept of the new digital substation? What is the difference with ordinary substation?

Digital substation is a modern substation constructed by intelligent primary equipment (electronic transformers, intelligent switches, etc.) and networked secondary equipment in layers (process layer, interval layer, station control layer), and built on the basis of IEC61850 communication specification, which can realize the information **** enjoyment and interoperation between intelligent electrical equipment in the substation. Digital substation is a substation that applies IEC61850 for modeling and communication. Digital substation is embodied in the digitization of process layer equipment, the networking of information in the whole station, and the realization of intelligent switchgear.

Functional features:

In HV and EHV substations, I/O units for protection, measurement and control, fault recording and other automation devices, such as A/D converters, opto-isolators, and control and operation circuits, are listed as part of the intelligent primary equipment. In other words, the digital sensors of intelligent primary equipment, digital control loop instead of conventional relay protection devices, measurement and control devices, such as I / O part; and in the low-voltage substations will be protected, monitoring device miniaturization, compact, complete installation in the switchgear, the realization of the substation electromechanical integration design.

Performance indicators:

In the field of substation automation, the development of intelligent electrical, especially intelligent switches, photoelectric transformer mechatronic equipment, substation automation technology has entered a new stage of digitalization.

The main features of the new digital substation system consists of four parts:

(1) All-digital and fiber-optic based signal acquisition system

(2) Relay protection and integrated automation system

(3) Digital remote monitoring system

(4) Intelligent and efficient power quality control system

Digitization The structure of substation automation system can be physically divided into two categories, i.e., intelligent primary equipment and networked secondary equipment; in the logical structure, it can be divided into three levels, which, according to the definition of the draft IEC6185A communication protocol, are called "process layer", "interval layer" and "station layer". The logical structure can be divided into three levels, which are called "process layer", "interval layer" and "station control layer" according to the definition of IEC6185A communication protocol.

The main advantages of the digital substation are six: First, a variety of functions **** with a unified information platform, to avoid repeated investment in equipment. Second, high measurement accuracy, no saturation, no CT secondary open circuit. Third, the secondary wiring is simple. Fourth, optical fiber instead of cable, electromagnetic compatibility performance is superior. Fifth, the information transmission channel can be self-checked, high reliability. Sixth, management automation. The main features of the digital substation are also six aspects: First, the substation transmission and processing of information is fully digitalized. Second, the process layer equipment intelligence. Third, a unified information model: data model, function model. Fourth, unified communication protocol: seamless data exchange. Fifth is high-quality information: reliability, integrity, real-time. Sixth, a variety of devices and functions **** enjoy a unified information platform.

These are not available in traditional substations.