With the explosive growth of distributed PV installations, tens of millions of distribution transformer areas across China are facing unprecedented challenges. Voltage violations, reverse power flow overloads, severe PV curtailment, and three-phase imbalance have become critical obstacles to achieving high-quality power supply at the distribution network edge.
However, conventional transformer-area energy storage solutions often struggle to address root causes. Limited dispatch precision, delayed response, and even secondary voltage rise issues caused by improper control have become common challenges.To address these pain points, Topology Electric Power has developed a dedicated PCS solution for distribution transformer area energy storage. At its core is the industrial-grade three-phase four-wire 125kW TPCS Series, which redefines distribution network management through three key advantages.
In distribution transformer area energy storage applications, efficiency directly translates into economic returns.The TPCS Series achieves a peak conversion efficiency of up to 99.1%, significantly exceeding the industry mainstream range of 98.0%–98.5%.
TPCS Efficiency Comparison
This is one of the most innovative features that differentiates the TPCS Series from conventional PCS products.In three-phase four-wire distribution networks, uneven residential single-phase loads and distributed PV connections often result in excessive neutral current, severe voltage deviation, and deteriorated power quality, creating risks for both grid operation and electrical equipment.
The TPCS Series supports fully independent three-phase control.
Using phase-by-phase control technology, each phase power unit can be regulated independently in both charging and discharging modes.
The system can charge one phase to absorb excess PV generation while simultaneously discharging another phase to support heavy loads.
In addition, it continuously monitors and dynamically compensates three-phase imbalance currents in real time, achieving 100% three-phase imbalance mitigation within the transformer area.
By enabling flexible power transfer between phases, the system compensates imbalance currents and suppresses zero-sequence components without relying heavily on battery cycling.
Independent Single-Phase Control by PCS
This reduces line stress, lowers power losses, and significantly improves power supply reliability. As a result, transformer loading is effectively reduced, voltage stability is substantially improved, and one of the industry's most challenging distribution network issues—three-phase imbalance—is fundamentally resolved.
Topology Electric Power's innovative inter-transformer-area energy-sharing solution goes beyond improving local PV consumption.
By combining intelligent charge-discharge strategies with multi-unit parallel technology, it enables energy sharing across neighboring transformer areas.
Based on real-time load profiles and PV generation curves, excess solar energy is prioritized for storage, reducing PV curtailment to extremely low levels.
The TPCS Series supports up to eight PCS units operating in parallel on the DC side, overcoming the capacity limitations of individual transformers.
During peak demand periods, neighboring transformer areas can share energy through the TPCS platform, significantly enhancing overall grid resilience.
Distribution Transformer Area Energy Storage & Power Sharing Topology
Typical Project Cases
The village had approximately 500 kW of rooftop PV installed capacity. At midday, end-user voltage frequently exceeded 260 V, while PV curtailment rates reached 35%.
One 125 kW TPCS unit combined with a 261 kWh energy storage cabinet was deployed.
Voltage was stabilized at approximately 230 V, and the PV curtailment rate dropped from 35% to below 2%, significantly improving economic returns for local residents.
A high concentration of single-phase EV charging stations resulted in a three-phase imbalance rate exceeding 40%.
The transformer experienced severe overheating, and the neutral conductor was at risk of failure.
A 125 kW TPCS unit was deployed as a dynamic balancing system.
Leveraging its independent three-phase control capability, the TPCS reduced neutral current by 85%, significantly lowered line losses, and completely relieved transformer operating stress.
Three-Phase Imbalance Mitigation: From Red Zone to Green Zone
Against the backdrop of China's 15th Five-Year Plan for power grid investment and modernization, Topology Electric Power remains committed to continuous technological innovation.We do not simply provide energy storage equipment—we deliver comprehensive solutions designed to address the unique challenges of complex distribution transformer area environments.Looking ahead, Topology Electric Power is eager to collaborate with partners worldwide to further advance the transformer-area energy storage market, enabling every distribution network to achieve safer, smarter, and more economical operation.
