Key Features:
- Moderate Power: Compared to traditional high-power DC fast chargers (e.g., 120kW to 1000kW), low-power DC charging stations operate at lower power levels, making them suitable for low-power charging environments.
- Modular Design: They utilize a modular structure, allowing for flexible combination and future expansion.
- Compatibility: Support for mainstream charging protocols (such as GB/T and CCS) ensures adaptability to various vehicle models.
- Application Scenarios: Primarily targets low-power, high-frequency charging demands in settings like residential communities, commercial parking lots, and logistics parks.
Advantages of Small DC Charging Stations
Cost Advantage
- Lower Hardware Costs:Components (e.g., transformers, SiC modules) are significantly less expensive than those for high-power chargers, reducing the cost per station by 30%-50%.
- Lower Installation Costs:Requires minimal upgrades to the electrical grid, making them ideal for older residential areas or locations with limited grid capacity.
Strong Scenario Adaptability
- High Energy Efficiency:Compared to AC charging stations (6.6kW-11kW), small DC chargers can replenish 20%-50% of a small vehicle's battery in 10-30 minutes, effectively meeting short-distance travel needs.
- High Frequency of Use:Suitable for high-frequency energy replenishment scenarios like ride-hailing services and logistics vehicles (e.g., last-mile delivery within communities), significantly reducing user waiting times.
Grid Support (Peak Shaving and Valley Filling)
Through intelligent scheduling systems, these chargers can prioritize charging during off-peak hours (e.g., at night), helping to reduce grid load pressure.
Distributed Deployment: Their decentralized placement minimizes the grid impact associated with centralized high-power charging stations.
Solution for Vehicles Without On-Board Chargers (OBC)
If a vehicle eliminates its OBC, users must rely on DC charging stations. Small DC chargers provide a complementary, cost-effective power replenishment solution for such vehicles, lowering overall vehicle costs while offering faster charging than AC options.
Examples:
Supercharging stations and small DC chargers (e.g., 60kW) complement each other, covering different user needs.
"OBC-less" vehicle models paired with community-based small DC chargers can effectively meet daily commuting requirements.
The development of small DC charging stations and the move by automakers to eliminate OBCs are mutually reinforcing trends. For automakers, it lowers the cost of new energy vehicles. For users, it means more affordable vehicles and faster charging speeds compared to AC charging. For society, small DC chargers use three-phase input voltage, which is preferred by the State Grid as it minimizes the risk of three-phase imbalance.
Disadvantages of Small DC Charging Stations Compared to High-Power DC Charging Stations
Charging Speed Limitation: Their lower power (20kW-80kW) means charging speeds cannot match high-power DC fast chargers (120kW+), resulting in lower energy replenishment efficiency for long-range vehicles (e.g., 70kWh and above).
Limited Applicability:
- Vehicle Matching Issues:Suitable mainly for small cars or low-energy-demand scenarios; they cannot adequately meet the needs of mid-to-large SUVs or long-distance travel.
- Grid Capacity Bottlenecks:In older communities or areas with insufficient grid capacity, operating multiple small DC chargers in parallel might still necessitate grid upgrades.
Technical and Maintenance Costs:
- Complex Maintenance:While modular design aids expansion, troubleshooting and maintenance can require more specialized technical skills.
- Energy Efficiency Optimization Challenges:The energy efficiency ratio (e.g., conversion efficiency) of low-power equipment can sometimes be slightly lower than that of high-power counterparts.
Market Competition Pressure
- Competition from High-Power DC Fast Charging:User preference often leans towards high-power chargers (120kW+), potentially leaving small DC chargers in a challenging "middle ground."
- Cost-Sensitive Markets:In price-sensitive markets (e.g., Southeast Asia, Africa), small DC chargers may face stiff competition from lower-priced AC charging stations.
The Necessity of Small DC Charging Stations
Meeting Niche Market Demands
- Compatibility for OBC-less Vehicles:As automakers introduce models without OBCs, users will depend on DC charging. Small DC stations offer a practical, low-cost solution for this need.
- High-Frequency, Short-Distance Scenarios:Ride-hailing services and community logistics vehicles require rapid power top-ups. Small DC chargers effectively fill the gap between high-power fast charging and slower AC charging.
Promoting Widespread Charging Network Coverage:
- Lowering the Charging Barrier:Their lower cost compared to high-power DC chargers accelerates the deployment of charging networks in low-density areas like communities and rural regions.
- Grid Adaptability:In areas with constrained grid capacity (e.g., old residential areas, remote regions), small DC chargers can be deployed without triggering extensive and costly grid upgrades.
A Transitional Solution for Technological Evolution
- Adaptation to 800V High-Voltage Platforms:As 800V high-voltage vehicles emerge, requiring DC fast charging, small DC stations can serve as an initial, transitional solution.
- Integration with PV, Storage, and Charging Trends:These chargers can be effectively combined with distributed photovoltaic and energy storage systems, facilitating the local use of clean energy.
Policy and Environmental Drivers
- Dual Carbon Goals: By supporting grid stability through peak shaving and valley filling, and enabling distributed deployment, small DC chargers align with carbon neutrality policies.
- Subsidy Policies: Financial subsidies in some regions (e.g., under China's "New Infrastructure" policy) for deploying small DC chargers in communities are accelerating market adoption.
Summary
Small DC charging stations play a crucial supplementary role in the widespread adoption of new energy vehicles:
- Short-term: They serve as a key solution supporting OBC-less vehicles and act as the primary charging equipment for high-frequency scenarios within communities.
- Long-term: They will collaborate with high-power DC fast chargers and integrated PV-storage-charging systems to build a comprehensive, multi-level charging network.
- Challenges: It is essential to balance cost, charging speed, and grid compatibility while also navigating the competitive pressures from advancing high-power DC fast charging technology.
- Recommendations: Automakers and charging operators should consider customizing deployment strategies for small DC charging stations based on user profiles (e.g., commuting radius, vehicle type) to foster growth in this specific market segment.
