Product Usage
It is mainly used in power plants, hydropower stations, various substations, switching stations, and user transformers to provide DC power for circuit breaker opening, closing, and control, signaling, protection, telecontrol communication, and fault lighting in the secondary circuit. It is used in fields such as electric power, petroleum, chemical engineering, metallurgy, machinery, paper making, building materials, textiles, brewing, etc.
Product composition
AC power distribution unit
Monitoring system module
Voltage regulating silicon chain module
Insulation monitoring module
High frequency switch rectifier module
Battery monitor
Battery pack
Feed unit
Principle and function of each component
AC power distribution unit: The AC system of the DC panel generally has two AC power inputs. Normally, the AC power input switch is set to the "automatic" position, with one circuit in operation and two circuits for standby. The AC power is sent to each charging module through the AC input air switch, AC contactor, lightning arrester, etc., to provide AC power for the high-frequency switch rectifier module.
Monitoring system module: The monitoring system for the DC screen is a human-computer interface with an LCD display. It serves as a bridge between the underlying module and background management, and is the brain of the DC screen. It is responsible for managing the charging module and the underlying automatic battery management, viewing current fault information, historical information records, and various parameters.
Voltage regulating silicon chain module: When the DC power supply system equalizes the charging of the battery pack, the output voltage of the charging module will be higher than the rated voltage of the control circuit. At this time, a voltage regulating device is required to adjust the voltage to supply power to the control bus circuit. The silicon chain module is such a voltage regulator that can automatically and manually change the voltage to ensure that the voltage of the control bus is within the range.
The step-down silicon chain unit uses the PN junction forward voltage drop superposition of high-power rectifier diodes to generate a regulated voltage drop. This method is reliable, has good impact resistance, and is easy to maintain.
Insulation detection module: used to monitor the DC system voltage and its insulation condition. In the event of abnormal conditions such as a decrease in insulation strength in the DC system (typically lower than 25K Ω for 220V DC voltage systems, and lower than 7K Ω for 110V DC voltage systems), an audible and visual alarm is issued, and the corresponding branch number and resistance value can be found.
High frequency switch rectifier module: The high frequency switch rectifier module is the heart of the DC screen and is responsible for providing power to the DC screen. On the one hand, it charges the battery, and on the other hand, it provides normal working current to the DC load. There is a monitoring board inside the charging module that can monitor and control the operation of the module. Since the charging module itself has a CPU, the charging module can also operate independently of the monitoring module.
Battery pack: As a backup power supply for the DC system of the entire station, when the charging module stops working, the battery continuously transmits power to the DC bus; In addition, during the closing operation of the electromagnetic circuit breaker, the closing current is greater than 100A, and the battery becomes the closing power supply. It is equivalent to a storage organization, which is the warehouse of the entire DC screen. As everyone knows, AC power cannot be stored, so the DC screen uses a battery pack to convert the DC power converted from the module into chemical energy, and when the AC power outage occurs, the chemical energy is converted into electrical energy to supply power to the DC load.
Environmental conditions
◆ The ambient temperature shall not be lower than - 5 ℃ and not higher than+40 ℃, and the allowable storage ambient temperature of the equipment shall be - 10 ℃~60 ℃
◆ The ambient relative humidity shall not exceed 90% (ambient temperature 25 ℃)
◆ The operation site is free of conductive dust, gases or vapors that corrode metal and damage insulation
◆ Use in indoor situations
◆ If there are special requirements, please put them forward when ordering to ensure the reliable operation of this product
◆ Altitude: altitude ≤ 2000m
System parameters
● Voltage stabilization accuracy: ≤± 0.5%
● Steady current accuracy: ≤± 0.5%
Ripple coefficient: ≤± 0.1%
● Power factor: ≥ 0.92
● Efficiency: ≥ 94%
● Noise: ≤ 45dB
● Current sharing imbalance: ≤ 3%
● Dielectric strength: 2000V/min without flashover or breakdown.
● Reliability index: MTBF ≥ 100000h
● AC voltage input range: 380V ± 15%
● AC voltage frequency range: 50Hz ± 10%
● Protection grade: IP ≥ 30
Operating principle of the system
The power operation power supply system is mainly composed of AC power distribution unit, charging module, monitoring module, power distribution monitoring, step-down silicon chain, DC feed unit, insulation monitoring, etc. The basic working principles of the system are as follows:
1. When AC input is normal
When the AC input of the system is normal, one of the two AC inputs is selected through the AC switching control circuit, and power is supplied to each charging module through the AC power distribution unit. The charging module converts three-phase AC power into 220V or 110V DC, and outputs it after being isolated by an isolation diode integrated in the charging module. On the one hand, it charges the battery, and on the other hand, it provides normal working current to the load.
The monitoring part uses a distributed method to monitor and control the system. The operating parameters of the charging cabinet and feeder cabinet, as well as the operating parameters of the charging module, are collected and processed by the data acquisition module, and then the processed information is reported to the monitoring module through the serial communication port. The monitoring module uniformly processes the information and displays it on the LCD screen. At the same time, the system can be set and controlled through human-computer interaction, and remote monitoring can be accessed if necessary. The monitoring module can also perform equalizing/floating charge control, current limiting control, etc. on the charging module to ensure normal battery charging and extend battery life.
2. When the AC input is powered off or abnormal
During normal float charging operation, when the AC input is powered off or abnormal, the charging module stops working. This is caused by the battery continuously supplying power to the load through the silicon chain system. The monitoring module monitors the battery voltage and discharge time. When the battery discharges to the set undervoltage point, the monitoring module gives an alarm. After the AC input returns to normal, the charging module charges the battery.
Monitor Introduction
The power monitor is the control and management center of the entire DC system; The main task of the power monitor is to automatically monitor each functional unit and battery in the system for a long time, obtain various operating parameters and states in the system, process them in real time based on measured data and operating states, and control the system based on this.
Adopt a distributed power monitor with a microprocessor as the core and a modular design to monitor and control the insulation of AC power distribution, DC feed, rectifier modules, battery packs, and system branches.
