A voltage sag lasting less than one-tenth of a second is enough to bring an entire chip packaging line to a standstill. Variable-frequency drives trip, PLCs reset, contactors drop out, batches of work-in-progress are scrapped, and the line takes hours to ramp back up. For precision manufacturing, the grid never went down, yet the loss has already happened — this is a voltage sag, the "invisible killer" of industrial power whose frequency of occurrence far exceeds that of outages. The solution from Tianjin Plannano Technology Co., Ltd. (PLANNANO) is a combination of a Dynamic Voltage Restorer (DVR) and a supercapacitor energy storage system: within one millisecond of a sag, it takes over the supply and steadily lifts the voltage back to its rated value.
I. DVR Dynamic Voltage Restorer: Acting Before Equipment Trips
The working logic of a DVR is not complicated — what is difficult is the speed. When the mains supply is normal, the load is fed directly from the grid through thyristors, and the device consumes almost no energy. The moment the voltage is detected to fall below the set threshold, the thyristors disconnect within milliseconds, and the inverter immediately draws energy from the supercapacitors to deliver standard sinusoidal AC power to the load — from detection to takeover, the entire process takes no more than 1 millisecond, faster than the response time of any protective device.
Key specifications of the PLANNANO DVR include: the minimum residual voltage it can protect down to is 0% — it can catch the load even if the grid voltage falls to zero; the continuous compensation time at rated power is no less than 8 seconds; beyond mitigating sags, it can also compensate voltage swells of up to 130%; with a 100% unbalanced load, the voltage unbalance is less than 4%; with linear loads, the total voltage harmonic distortion is below 2.5%; overall efficiency is no lower than 99%, with operating losses under 1%. The device is phase-locked and synchronized with the mains, transitioning smoothly back to the grid when the supply recovers, with no fluctuation perceptible on the load side; in the event of an internal fault, the automatic bypass switch transfers the load directly back to the mains, so the device itself never becomes the cause of a blackout.
The recording capability is equally complete: no fewer than 500 waveform records, capturing the RMS value, instantaneous waveform, sag depth, and duration of every voltage disturbance, exportable via a USB drive. For factories that need to trace and present evidence to the grid company, this data is evidence in itself.
II. Why Supercapacitors, Not Batteries
An 8-second compensation window falls exactly within batteries' awkward zone: too short for their energy advantage to matter, while response speed and cycle life are their inherent weaknesses. Supercapacitors are exactly the opposite — they store energy not through chemical reactions but through charge adsorption on the electrode surface, which gives them high power density, fast response, and an extremely long cycle life.
PLANNANO supercapacitors use 3000F cylindrical cells produced on fully automated lines, with an impedance-matched power density of 23.8 kW/kg — this figure is what enables the system to deliver enough power within 1 millisecond to "catch" the load. Together with the Capacitor Management System (CMS), the Power Conversion System (PCS), and the Energy Management System (EMS), the entire supercapacitor energy storage system connects to the 0.4 kV AC busbar under centralized, intelligent control.
III. "Customization" Is Not a Slogan: 350kW/8s Is Just One Coordinate
There is no standard product in voltage sag mitigation. The load power, how deep a sag the most sensitive equipment can tolerate, and the quality of the grid together determine that every project differs in capacity and compensation duration. PLANNANO's solution is modular: the 72V/250F module is the building block; thirteen modules in series form a 936V/19.2F string; the number of strings determines power and duration — 350kW/8s is merely one typical configuration. Need more power? Parallel more strings. More frequent sags? Increase the capacity.
The complete system is designed in accordance with national standards for energy storage and power quality such as NB/T 33015 and GB/T 14549. Key components include Infineon IGBTs, Schneider/ABB bypass switches, and Taigui thyristors, while the supercapacitor modules are manufactured in-house by PLANNANO. From cells and modules to CMS, DVR, and EMS, every link is completed within one system — when something goes wrong, there is no finger-pointing among multiple suppliers.
For industries such as chip manufacturing, data centers, precision CNC machining, and chemical fiber spinning — where a single trip means real money — the economics of voltage sag mitigation are easy to calculate: the investment in one DVR plus one supercapacitor system is often less than the loss from one or two major line stoppages. Based on your line's load characteristics and measured grid data, PLANNANO delivers customized industrial voltage sag mitigation solutions spanning capacity calculation, topology design, delivery, and O&M — seize that one millisecond before the voltage falls.
About PLANNANO
Founded in 2009 and headquartered in Tianjin, Tianjin Plannano Technology Co., Ltd. has three wholly-owned subsidiaries: Plannano Energy, Plannan Energy Storage, and Saimei Technology. The company is dedicated to the development and application of novel nanomaterials in the new energy sector, holding outstanding technical advantages and extensive process expertise — at an internationally advanced level — in graphene volume application, new battery materials, dry electrode technology, and full-tab technology.
