Power Solution for Smart Substation Application
(1) The basic construction of a smart substation
Process level consists of smart equipment, MU(Merging units) and smart terminals that are made up of primary equipment and smart components, aiming at the electric distribution of substation, conversion, transmission, detection, control, protection, metering, state monitoring, etc. According to the requirements of the state grid, protection should be sampled directly, single interval protection should be tripped directly, multi-interval protection (bus protection) shall be tripped directly. Smart components are the physical device which can configure flexibly, it contains detection units, controlling units, protection units measurement units, and condition monitoring units more or less.
Bay level generally includes relay protection device, detect and control device, fault filter, and other secondary equipment. It can make use of one interval data and have an influence on the one interval, namely communicates with various remote inputs/outputs, smart sensors, and controllers.
The station-level includes sub-systems like automation system, control system for standing area, communication system, and standard time system, etc. It is used to meet the function of the primary device, to detective and control the whole or more than one station device, and to perform the function of data collection, monitoring control(SCA-DA), lockout operation, and synchronous phase collection, electric energy collection, information protection, and relevant function.
(2) Which equipment will use a power supply? Monitoring Device & Protection Device
1. Communication failure detector
2. SF6 gas leakage monitoring system
3. The electronic harmonic analyzer
4. The fault wave record device, etc.
1. Microcomputer protection devices
2. Current limiting intelligent protector
3. Intelligent circuit controller, etc.
1. Circuit breaker online monitoring
2. Standard time system
3. Low voltage motor protection controller
4. The integrated online monitoring system
5. Smart electricity meter etc.
(3)Typical application: Online monitoring’s typical structure of Smart Substation
The system transmits the signal to MCU through the processing circuit. On one hand, it is displayed and protected by MCU; on the other hand, it is transmitted to the engineer station by MCU to be saved, analyzed, processed, alarmed, etc.
● By using AC-DC converter LH20-10D0524-02, the host power supply part meets the isolation transmission from high to low input voltage, meanwhile low input voltage restrains the impact of the main power supply circuit from the relay and other operation components because of isolation and dual outputs.
● Generally, there are dual outputs of the signal processing circuits, so A0515S-1WR2 with an output of ±15V can well ensure the reliability.
● Communication circuit will isolate the power supply and signal to ensure the accuracy, B0505LS-1WR2 has the 5 VDC input pass through isolation to generate an isolated 5VDC output to power supply the circuit.