01 What is Reverse Power Flow?

In grid-tied photovoltaic (PV) systems, excess solar power flows backward to the grid when generation exceeds local load demand. This reverse current direction—from PV panels → inverter → grid—is termed "reverse power flow" or "backflow", conflicting with standard grid operation.

02 How Backflow Prevention Devices Work

A backflow prevention device is an advanced power management system that:

Monitors real-time current direction via AC-side sensors

Automatically isolates grid connections when backflow is detected

Maintains energy self-consumption while preventing unauthorized grid injection

Critical Application:
When microgrid generation > load demand, direct grid disconnection risks dangerous islanding. Our ARM Cortex-M4-based backflow prevention device safely disconnects specific circuits instead of full grid isolation, enabling:
✔️ Zero reverse power export
✔️ Seamless grid resynchronization when demand rises
✔️ Compliance with strict no-export policies

03 Why Backflow Prevention is Mandatory

1. Grid Protection

• Blocks harmonic pollution (up to 5% THD from PV inverters)

• Eliminates voltage fluctuations (IEEE 1547-2018 standards)

• Prevents phase imbalance in weak grids

2. Regulatory Compliance

• Avoid penalties for unauthorized feed-in (common in Asia/EU markets)

• Enables off-grid solar operation where grid permits are pending

3. Infrastructure Safety

• Protects aging transformers from reverse current overload

• Reduces fire risks in undersized distribution lines

04 Types of Backflow Prevention Systems

05 Technical Implementation

Threshold Setting: Activate at 1-5% reverse power (adjustable via HMI)

Response Time:<100ms isolation to meet UL 1741 SA requirements

Communication: Modbus RTU/TCP for SCADA integration

06 Top 3 Benefits of Modern Backflow Prevention

1.Energy Autarky – Achieve 95%+ self-consumption rates

2.OPEX Savings – Eliminate grid export penalties up to $0.15/kWh

3.Future-Proofing – Compatible with smart meters and VPP systems

07 Market-Specific Solutions

EU: EN 50549-1 compliant models with CE certification

North America: UL 1741-certified devices for NEC 705.12 compliance

Emerging Markets: Low-cost versions with SMS alert functions