HV4 General Medium Voltage Drive is composed of 3 main parts:
1. transformer cabinet 2. power-cell cabinet 3. control system
Cell Bypass and Neutral Drift
Instant Power Loss
The medium-voltage input side is temporarily powered off (within 1s)
When the grid voltage drops below 90% of the rated value, the inverter limits the power output to the load. This limitation forces the drive to draw energy from the grid to maintain the DC bus voltage, waiting for the grid voltage to recover. The limit value varies as an inverse function of speed to ensure constant power flow to the DC bus.
Medium Power Loss Function
When the grid voltage drops for more than the instantaneous power outage time, the state at this time is called high voltage power outage. The user can choose whether the inverter will report a serious fault when a medium-voltage power outage occurs; and whether the inverter will run automatically when the power is restored.
Synchronous Switching Technology
For soft-starting and controlling multiple motors
Up-cut (inverter to grid):
After obtaining the up-cut request, the inverter measures the input voltage frequency, amplitude and phase of the grid side through the phase-locked loop;
At the same time, the inverter takes the input frequency of the grid side as the running frequency;
When the frequency, amplitude and phase synchronization between the inverter and the grid side is completed, the input contactor of the inverter is disconnected, and the inverter coasts to a stop.
Down Cut (Grid to Drive):
After the down-cut request is obtained, the input contactor of the inverter is disconnected, the rotating load function is activated, and the motor speed is tracked to switch to the inverter running state through the speed start function.
While there are a number of variations in Hiconics variable frequency drive design; they all offer the same basic functionality which is to convert the incoming electrical supply of fixed frequency and voltage into a variable frequency and variable voltage that is output to the motor with a corresponding change in the motor speed and torque.
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Hiconics with the newest generation VFD can provide different load types, different current scope of the power cells, which can meet most of the industrial and mining enterprises control requirements.