Sinopak dynamic voltage regulator (DVR)

The normal operation of equipment depends on quality power supply voltage. However, voltage disturbance of the voltage distribution network is a common problem.
The AVC products series can provide an online real-time voltage compensation solution. In case of voltage drop and swell and other problems, the equipment supports quick power failure compensation for the load, which will ensure the integrity of the power supply voltage until the power supply of the grid returns to normal.
Because of the application of revolutionary inverter rectification and shutdown technology, the transient characteristics of equipment operation have been improved, which makes the AVC effectively and quickly compensate for the voltage swell/ drop of the power grid.
 

The AVC system consists of 5 main modules
a. Rectifier module
b. Power transformer
c. Inverter module
d. Master module
e. Maintenance bypass
The combination of all module components constitutes the entire AVC system.
 

The rectifier module mainly aims to convert the three-phase alternating current into direct current, and the modular design of the rectifier is easy for maintenance and replacement. Each module has its own identification code (10-19). When the modules are powered on for the first time, the master module assigns the codes, which are only used for module identification. Modules with the same code will be recoded. At present, 1 rectifier module can be placed in the 300K cabinet and 2 rectifier modules can be placed in the 600K cabinet and 3 rectifier modules can be placed in 900K cabinet.
Close the rectifier miniature circuit breaker, and the rectifier will start a soft start process for about 2 minutes after the system is powered on normally. After the process, the rectifier works normally to provide the inverter with stable bus voltage to cope with grid problems.
 

The power transformer is equipped with temperature detection protection. The transformer shall be connected in series into the grid. In case of a voltage drop, the inverter quickly switches from bypass state to inversion state to provide proper voltage to the transformer primary side for compensation.
The main function of the power transformer is to make the voltage range span reach the model class. The nominal inverter voltage is a set value, however, the grid voltage may be 208V, 400V, 480V, 600V, etc.;

The main function of the inverter module is to convert direct current to three-phase alternating current. The design of the inverter module is easy for maintenance and replacement. Each module has its own identification code (20-29). When the modules are powered on for the first time, the master module assigns the codes, which are only used for module identification. Modules with the same code will be recoded. It should be noted that there must be a corresponding rectifier module for the inverter to operate normally, and one rectifier module corresponds to one inverter module, and the buses of each pair of modules are independent.
After the system is started, the rectifier module is in the soft start stage and the bus voltage is low. In this case, the inverter module will report the situation. When the rectifier charges the bus to the specified value, the alarm of low bus voltage will be cleared automatically, and then the inverter can be started normally to cope with the grid voltage problems normally.
 

Complete machine coordination and system capacity allocation of the AVC system are completed through the master module. The module collects the operation information of the system for analysis and uploads it to the monitoring module on the side door for display. When a power module in the system fails, the total system capacity to be borne by the remaining power modules will be allocated by the master control module.

The front panel of the master module has two LED indicators indicating the working statuses of the two internal core chips of the module, respectively. Generally, they are normally On in green. When they are flashing, it means that the master control is resetting, and when Off, it means that a failure is caused.

6. Operation instructions for maintenance bypass
Before the whole system is powered on for the first time, the current status of each switch in the cabinet must be checked for ensuring that Maintenance Bypass Switch QF1 is OFF, and Input Switch QF2 and Output Switch QF3 are ON. After checking and everything is OK, the system can be powered on and started.
When the AVC system is required to be maintained or repaired, the steps below should be followed:
1. Tap the Start/Stop button on the monitoring operation panel, and tap Stop- OK button to make the AVC host be Off;
2. Rotate Maintenance Bypass Switch QF1 lever to make it be ON;
3. Disconnect the Input Switch QF2 and Output Switch QF3 levers in turn to make QF2 and QF3 be Off (the levers shall be horizontal).
After the above operations, the AVC host has been completely disconnected from the power grid and load. In this case, the load is powered by the grid, and the AVC will not take any protective action in the event of a sag, swell, or power failure in the power grid. During this period, the power supply to the load should be ensured by the user.