• Zhejiang Zhilu Transmission and Distribution Equipment Co., Ltd

Outline Dimensions and Installation Space Planning of Photovoltaic Grid - Connection Cabinets

Abstract

1. Introduction

• Compatibility: Ensuring the cabinet fits within available installation areas (e.g., rooftops, utility rooms, outdoor enclosures).

• Accessibility: Providing sufficient space for component maintenance, cable routing, and safety compliance.

• Scalability: Allowing room for future capacity expansion or equipment upgrades.

2. Influencing Factors of Outline Dimensions

2.1 Electrical Capacity and Component Configuration

• Power Rating: Larger - capacity cabinets (e.g., for 10MW+ PV systems) require more internal space to accommodate high - current circuit breakers, transformers, and busbars.

• Component Quantity: Additional features (e.g., multiple protection relays, advanced monitoring modules) increase cabinet size. For example, cabinets with integrated power quality analyzers are 10–20% larger than basic models.

2.2 Protection and Cooling Requirements

• Ingress Protection (IP) Rating: Higher - rated cabinets (e.g., IP65 for outdoor use) have thicker walls and sealed enclosures, increasing overall dimensions.

• Thermal Management: Cabinets with forced - air cooling systems (fans, heat exchangers) or liquid - cooled components require extra space for ventilation ducts or cooling pipes.

2.3 Standardization and Modularity

• Industry Standards: Compliance with international dimensions (e.g., IEC 60439 for low - voltage switchgear) influences cabinet size. Standardized rack - mount units (e.g., 19 - inch racks) simplify integration but limit customization.

• Modular Design: Some cabinets use a modular structure, allowing users to add or remove functional units, which can affect both initial size and expandability.

3. Typical Outline Dimensions and Specifications

3.1 Small - Scale Grid - Connection Cabinets (≤1MW)

• Dimensions:

• Width: 600–800 mm

• Depth: 800–1000 mm

• Height: 1600–2000 mm

• Features: Compact design, suitable for rooftop or small - space installations; may use integrated inverters and simplified protection circuits.

3.2 Medium - Scale Grid - Connection Cabinets (1–10MW)

• Dimensions:

• Width: 800–1200 mm

• Depth: 1000–1500 mm

• Height: 2000–2200 mm

• Features: Accommodate larger - capacity circuit breakers, multiple protection relays, and separate compartments for MV and LV sections.

3.3 Large - Scale Grid - Connection Cabinets (>10MW)

• Dimensions:

• Width: 1200–1800 mm

• Depth: 1500–2000 mm

• Height: 2200–2500 mm

• Features: Include advanced monitoring systems, redundant power paths, and enhanced cooling mechanisms; often designed for outdoor, free - standing installations.

4. Installation Space Planning Principles

4.1 Clearance Requirements

• Front Clearance: Minimum 1.2–1.5 meters in front of the cabinet for door opening, equipment access, and maintenance.

• Side and Rear Clearance: 0.6–0.8 meters to allow cable routing, ventilation, and access to rear - mounted components.

• Vertical Clearance: Ensure sufficient overhead space (≥2.5 meters) for lifting equipment during installation or replacement of heavy components.

4.2 Cable Routing and Management

• Entry/Exit Points: Plan cable entry/exit locations (top, bottom, or side) based on the site layout. Allocate 15–20% extra space for future cable additions.

• Cable Tray Installation: If using cable trays, reserve space above or below the cabinet with a minimum depth of 200–300 mm.

4.3 Environmental Considerations

• Outdoor Installations: Account for additional space for weatherproof enclosures, foundation supports, and anti - corrosion measures.

• Indoor Installations: Ensure proper ventilation and fire - resistant separation from adjacent equipment, following local building codes (e.g., NFPA 70).

5. Space - Saving Design Strategies

5.1 Modular and Compact Component Selection

• Integrated Devices: Use multi - function relays or combined circuit breaker - switchgear units to reduce component count.

• Miniaturized Equipment: Select low - voltage components with smaller footprints, such as compact circuit breakers or micro - PLCs for control.

5.2 Vertical and Horizontal Layout Optimization

• Vertical Stacking: In tall cabinets, arrange components vertically (e.g., MV section on top, LV section below) to minimize floor space.

• Side - by - Side Installation: For multiple cabinets, design a shared busbar system to reduce individual cabinet size and simplify inter - cabinet connections.

5.3 Prefabricated and Containerized Solutions

• Containerized Cabinets: For large - scale projects, use prefabricated, shipping - container - sized units that integrate multiple grid - connection functions, reducing on - site installation space requirements.

6. Case Studies and Practical Examples

6.1 Rooftop PV Project

• Challenge: Limited rooftop space restricts cabinet size.

• Solution: Select a compact, IP65 - rated cabinet (800×1000×1800 mm) with integrated MPPT controllers and miniaturized circuit breakers. Install the cabinet against a wall to optimize floor space, leaving a 1 - meter front clearance for maintenance.

6.2 Utility - Scale PV Power Plant

• Challenge: Need to accommodate high - capacity equipment and future expansion.

• Solution: Design a modular, outdoor - rated cabinet (1500×2000×2500 mm) with a double - busbar system. Allocate 2 - meter clearances around the cabinet for cable routing and equipment access, and 预留 space for adding additional cabinets in parallel.

7. Conclusion