Building integrated photovoltaic (BIPV) technology combines photovoltaic power generation with architectural design, which not only improves the aesthetics of the building, but also gives the building the ability to generate electricity by itself. Photovoltaic electrical design is the key to the successful implementation of the BIPV project. This paper will provide learners with BIPV project photovoltaic electrical design learning points analysis.

Part I: Overview of Photovoltaic Electrical Design

Composition of 1.1 photovoltaic electrical system

The photovoltaic electrical system of the BIPV project is mainly composed of photovoltaic modules, inverters, DC combiner boxes, and AC distribution cabinets. These devices work together to convert solar energy into electricity and deliver it safely and efficiently to the grid or to the user's end.

1.2 Design Objectives

The goal of the design is to ensure the reliability, safety, efficiency and economy of the system. Factors that need to be considered in the design process include geographic location, installation angle, component configuration, system capacity, etc.

Part II: PV module selection and design

2.1 Component Type

Photovoltaic modules can be divided into crystalline silicon (monocrystalline silicon, polycrystalline silicon), thin film (cadmium telluride, copper indium gallium selenium, amorphous silicon) and other types. Each type of component has different performance parameters and application scenarios.

2.2 Component Parameters

Learners need to be familiar with the electrical parameters of the components, such as open circuit voltage, short circuit current, maximum power point, etc., and make a reasonable selection according to the project requirements.

2.3 Component Layout

The layout design of the components needs to consider the building structure, sunshine conditions, shadow analysis and other factors to maximize the power generation efficiency.

Part III: Selection and design of electrical equipment

3.1 Inverter Selection

The choice of inverter shall be based on the DC voltage, current and power requirements of the system. The inverter shall have the functions of high/low voltage blocking and automatic grid connection with voltage detection.

3.2 DC bus equipment

The selection of DC confluence equipment should consider the safety and economy of the system. The intelligent DC combiner box provides higher safety and monitoring functions.

3.3 AC power distribution cabinet

The AC distribution cabinets shall be designed to meet the electrical requirements of the project with appropriate protective measures.

Part 4: Electrical System Design

Calculation of 4.1 electrical parameters

Learners need to master the basic electrical parameter calculation, such as DC voltage, current calculation, and power estimation.

4.2 cable selection and layout

Cable selection shall be based on current capacity, voltage level and environmental conditions. Cable layout should consider safety, concealment and maintenance convenience.

4.3 electrical safety design

Electrical safety design includes overload protection, short circuit protection, grounding and lightning protection design.

Part 5: Design and Construction Drawings

Preparation of 5.1 design drawings

The design drawings include photovoltaic group string diagram, DC combiner box system diagram, inverter group string diagram, grid-connected system diagram, bridge/cable routing diagram and photovoltaic monitoring schematic diagram.

5.2 Structural Design Drawings

The structural design drawings include support layout drawings, installation details, system node drawings, and material blanking/listing drawings.

Part VI: Practical Case Analysis

6.1 Case Study

By analyzing specific BIPV project cases, such as representative photovoltaic curtain wall project, photovoltaic lighting roof project, learners can better understand the application of theoretical knowledge in practice.

6.2 Project Evaluation

Learners should learn how to assess the technical feasibility, economics and environmental impact of a project.

The photovoltaic electrical design of the BIPV project is a comprehensive and technically demanding process. Through the study of professional system, we should be able to master the basic process, key technology and design points of photovoltaic electrical design of BIPV project. With the continuous advancement of technology and the development of the market, BIPV technology is expected to play a more important role in the future construction field. Learners should keep their attention to new technologies, new materials and new norms, and constantly improve their design capabilities to meet the needs of industry development.