The 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 AC input switch working and the other standby. The AC power is sent to each charging module through the AC input air switch, AC contactor, and lightning arrester to provide AC power for the high-frequency switch rectifier module.
Monitoring system module: DC screen monitoring system is a man-machine interface with LCD display, it is the bridge between the bottom module and the background management, is the brain of DC screen, responsible for the management of charging module and the bottom of the battery automatic management, view the current fault information, historical information records and various parameters.
Voltage regulating silicon chain module: When the DC power system charges the battery pack in a balanced way, the output voltage of the charging module will be higher than the rated voltage of the control loop. In this case, a voltage regulating device is needed to adjust the voltage to supply power to the controller loop. Silicon chain module is such a voltage regulator, can automatically and manually change the size of the voltage, and ensure that the control bus voltage within the range.
The step-down silicon chain unit uses the PN junction of the high power rectifier diode to generate the adjusted voltage drop. This method is reliable, good impact resistance and easy maintenance.
Insulation detection module: Monitors the voltage and insulation of the DC system. When the insulation strength of the DC system decreases (for a 220V DC voltage system, the insulation strength is lower than 25KΩ, and for a 110V DC voltage system, the insulation strength is lower than 7 kω), the module generates an audible and visual alarm and finds the corresponding branch number and resistance value.
High-frequency switch rectifier module: The high-frequency switch rectifier module is the heart of the DC panel, responsible for providing power to the DC panel, on the one hand to charge the battery, on the other hand to provide normal working current to the DC load. There is a monitoring board inside the charging module to monitor and control the operation of the module. Since the charging module itself has a CPU, the charging module can also run independently from the monitoring module.
Battery bank: As the backup power supply of the DC system of the whole station, when the charging module stops working, the battery sends power to the DC bus without interruption; In addition, when the electromagnetic circuit breaker is operated, the closing current is greater than 100A, and the battery becomes the closing power supply. It is equivalent to a storage institution, is the warehouse of the whole DC panel, we all know that AC power cannot be stored, so DC panel uses battery pack to convert the DC electricity converted from modules into chemical energy, and when AC power failure, the chemical energy is converted into electric energy to power the DC load.
