Dynamic Voltage Regulator
HTDVRs Dynamic Voltage Regulators (DVR) are innovative solution to protect against voltage sags and swells that cause a significant amount of manufacturing downtime in manufacturing processes and damaged sensitive loads.
HTDVR DVRs are based on Insulated Gate Bipolar Transistors (IGBT) inverter technology and using supercapacitors as energy storage components. They can provide protection for sags with zero voltage remaining (100% depth) for 3 seconds as standard. In case of voltage sags and swells, our HTDVRs can response within 100μs provide protection within 3ms.
How Does Dynamic Voltage Regulator Works?
The primary circuit of HTDVR mainly compose of four-quadrant charger, supercapacitors, inverters, injection transformer, static switch, automatic transfer switch. The static switch is connected in series between the mains power supply and the protected loads.
For the protected loads, the output voltage of HTDVR is seamlessly switched from the main power to the inverter generated power, and the power supply of the load is not interrupted to ensure the stable operation of the equipment.
The biggest advantage of energy storage type sag solution is that whether it is a single-phase, two-phase or three-phase dips, or even a dip with zero voltage remaining, it can provide qualified power for the load.
There are four states for the HTDVR, that is, Standby State, Compensation State, Recovery State, and Bypass State.
Standby State
When the grid voltage is within the normal range, the HTDVR standby. In this state, the incoming circuit breaker QF is closed, the static switch STS1 is closed, and the automatic transfer switch ATS works in the main power state (Qn). Mains power is supplied directly to the load through the static switch and The output voltage is the grid voltage.
In addition, the super capacitor is in full power state. The inverters are in a hot backup state and is synchronized with the grid voltage in real time so that it can act immediately when there is voltage disturbance.
Compensation State
The HTDVR monitors the grid voltage in real time. If the grid voltage exceeds the preset range, which means voltage sag or swell occurs, the HTDVR immediately controls the static switch to be open, and the protected loads are completely isolated from the mains power.
The energy stored in supercapacitors will be converted to AC power and is supplied to the protected loads through the injection transformer. The HTDVR matches the output voltage to be the same voltage and phase of the grid sine wave AC waveform before sag or swell happens. Seen by the protected loads, the switch between mains power and inverted power is seamless, and the power supply of the load is not interrupted to ensure the continuous operation of the protected loads.
Recovery State
When the HTDVR monitors the grid voltage returns to normal value, it will control the output voltage accurately match the voltage and phase of the grid sine wave AC waveform. Once the synchronization finished, HTDVR will control the inverters stopping working and control the static switch to be turned on. In this way, the output voltage returns to be the grid voltage, and the supercapacitors begin to be charged in preparation for the next compensation.
Bypass State
In the case of HTDVR failure or maintenance, the automatic transfer switch can operate automatically or manually. The mains power will directly be provided to the loads through the bypass loop which is connected in parallel with the both ends of the HTDVR. In the bypass state, the HTDVR will not respond to abnormal events of the power grid.
Features and Benefits
l Nominal input voltage from 208 to 690 Vac
l Solutions for medium voltage upon request
l From 30 to 2000 kVA (other on demand) per unit
l Multiple units can be in parallel for higher power applications
l Turnkey project: tailor-made design for special needs
Unrivalled Sag Ride Through Performance
l Protection against one-phase, two-phase, three-phase voltage sags up to 100% of depth
l Compensation of balanced and unbalanced voltage drops
l Swell compensation up to +30%
l Instantaneous response time <100μs
l Complete response time <3ms。
l 3 seconds of ride through as standard, other ride through time available upon request
l Continuous smooth compensation with compensation waveforms seamless with pre-sag waveforms
l Pure sure wave output
Proven Technology
l Grid-tie inverter control algorithm for seamless transfer
l 3-level IGBT inverter topology for reduced power loss and compact size
l Dual-DSP controller for real-time voltage and phase tracking and dynamic compensation
l Supercapacitors ideal for rapid charge/discharge cycles with extremely high charge/discharge efficiency
Minimal Total Operational Expenditure
l Extremely high efficiency >99%, meaning much lower ongoing cost of ownership than traditional UPS solutions and much less needed heat dissipation from the room in which the DVR is located
l Battery-free sag solution eliminating requirement to swap batteries every 3-5 years
l Automatic operation without manual intervention
Maximum Reliability and Life-span
l Rugged industrial design
l Robust static switch with unmatched reliability and overload capability
l Inverter modules with redundancy design and only in operation during voltage disturbances
l All inverter modules identical for easy maintenance
l Name-brand supercapacitors with charge/discharge cycles up to one million times
l Built-in supercapacitor management system allowing for real-time state monitoring to ensure safe operation and extended life-span
l Optical fibers between controller module and inverter modules for immunity to electromagnetic interference
l Name-brand automatic transfer switch equipped in case of inverter failure
l Four-quadrant charger for safe discharge of supercapacitors before maintenance
Flexibility and Easy Integration
l Thanks to the ultra-high power density of supercapacitors, HTDVRs provides ultra-dense footprint reducing the demand on valuable real estate
l Compensation threshold programmable on site according to the sensitivity of the protected loads.
l No special ventilation design for the installation room due to minimal heat dissipation
Powerful and user-friendly HMI
l 10-inch true-color TFT touch-screen
l Graphical user interface and mimic panel for local system monitoring and configuration
l Time-stamped event records are stored in history page for quick troubleshooting
l Multiple-language menu
l Quickly understand unit and power status with extensive state display of IGBTs, inverters, controller
l Alarm, history and event logs
l RS485 interface, MODBUS protocol as standard, TCP/IP protocol optional