Integrated PV-Storage-Charging System Design Drawing

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I. Project Overview

1. Project Name: Integrated Photovoltaic-Storage-Charging-Inspection-Replacement Station Project

2. Project Location: XXX

3. Geographical Location: 106.076°E: 29.86°N

4. Installed Capacity: 971.3kWp (Phase I: 278.85kWp, Phase II: 692.45kWp)

5. AC Side Capacity: 790kW (Phase I: 240kW, Phase II: 550kWp)

6. Grid Connection Mode: Self-consumption with surplus power fed into the grid.

II. Design Basis

1. *Design Code for Photovoltaic Power Stations* (GB50797-2012)

2. *Standard for Electrical Design of Civil Buildings* (GB51348-2019)

3. *Code for Fire Protection Design of Buildings* (CB50016-2014) (2018 Edition)

4. *Technical Standard for Application of Building Photovoltaic Systems* (GB/T 51368-2019)

5. *System Grounding Type and Safety Technical Requirements* (CB 14050-2008)

6. *Design Code for Power Supply and Distribution Systems* (GB 50052-2013)

7. *Design Code for Low-Voltage Power Distribution* (GB 50054-2011)

8. *Power Quality—Voltage Fluctuations and Flicker* (CB/T 12326-2008)

9. *Power Quality—Public Grid Harmonic Speed* (GB/T 14549-1993:

10. Power Quality - Three-Phase Voltage Imbalance (CB/T 14543-2008);

11. Power Quality - Supply Voltage Deviation (GB/T 12325-2008);

12. Technical Requirements for Grid Connection of Photovoltaic Systems (CB/T 19939-2005);

13. Technical Regulations for Photovoltaic Power Stations Connected to Power Systems (GB/T 19964-2012);

14. Code for Lightning Protection Design of Buildings (GB 50057-2010);

15. Design Code for 20kV and Below Substations (GB 50057-2010) 50053-2013)

16. *Code for Overvoltage Protection and Insulation Coordination Design of AC Electrical Installations* GB/T50064-2014.

17. *Code for Grounding Design of AC Electrical Installations* CB/T50065-2011

18. *Code for Design of Photovoltaic Power Generation System Access to Distribution Network* GB/T50865-2013.

19. *Technical Regulations for Photovoltaic Power Generation System Access to Distribution Network* GB/T29319-2012:

20. *Efficiency Specification for Photovoltaic Power Generation System* NB/T1 0394-2020:

21. "Typical Design of Distributed Power Generation Access System" (State Grid Corporation of China)

22. "Typical Design of Distributed Photovoltaic Power Generation Access System" (State Grid Corporation of China)

23. Other relevant national and local current regulations and standards

III. System Scheme

1. The installed capacity of this project is approximately 971.3 kWp, consisting of 1766 550Wp high-efficiency monocrystalline silicon solar cell modules.

1# Photovoltaic Zone: Ground-mounted photovoltaic modules use 183 550Wp monocrystalline single-sided solar panels, with an installed capacity of 100.65kW. Connected to one 100kW inverter, using fixed bracket installation.

#2 Photovoltaic Zone: 90 550Wp monocrystalline single-sided solar panels, with an installed capacity of 49.5kW, connected to one 40kW inverter, using fixed bracket installation.

#4 Photovoltaic Zone: 234 550Wp monocrystalline single-sided solar panels, with an installed capacity of 128.7kW, connected to one 100kW inverter, using vehicle-mounted BIPV installation.

#4 Photovoltaic Zone (Phase II): The solar panel system uses 1259 550Wp monocrystalline single-sided solar modules, with an installed capacity of 692.45KW. It is connected to five 100KW inverters and one 50KW inverter, using both ground-mounted brackets and single-axis brackets.

2. This project adds two low-voltage grid-connected metering cabinets, located outdoors.

3. The grounding grid of the newly added cabinets is reliably connected to the company's existing grounding grid.

IV. DC System

1. 1766 550Wp monocrystalline silicon solar modules are adopted, with 15/16/18/19/20 modules connected in series to form a string.

V. Inverter System

1. This project uses one 40kW (4 MPPT, 8 inputs) string inverter, one 50kW string inverter (5 MPPT, 10 inputs), and seven 100kW string inverters (10 MPPT, 20 inputs).

2. The string inverters output three-phase 380V AC power at a frequency of 50Hz, with a maximum total harmonic distortion of <3% and an adjustable power factor of +0.99.

3. The string inverters should have protection functions including islanding protection, short-circuit protection, output overcurrent protection, output overload protection, output over/undervoltage protection, and output over/underfrequency protection.

VI. Metering

1. Install one 380V, 0.5S class, 1.516)A three-phase four-wire smart meter and one 380V, 0.2S class, 600/5 current transformer in the No. 1 low-voltage grid-connected cabinet.

2. Install one 380V, 0.5S class, 15(6)A three-phase four-wire smart meter and one 380V, 0.2S class, 500/5 current transformer in the No. 2 low-voltage grid-connected cabinet.

3. A new 10kV high-voltage metering system needs to be built at the property boundary point. This time, it will be directly constructed as the metering system for the energy at the border crossing.

4. This metering plan is subject to the final approval of the power company.

VII. Equipment Installation

1. Use flat or bracket installation methods. The installation of components must be carried out in accordance with the relevant structural professional support drawings.

2. The support manufacturer needs to conduct on-site testing of the fixtures to determine the type of fixtures.

3. After the first set of supports is manufactured, a trial installation is required. Before ground installation, the clamps must undergo pull-out and anti-slip tests (the design pull-out force of a single clamp perpendicular to the roof panel must be 20.8KN). A corresponding pull-out test report must be provided to the design institute, and construction can only proceed after the design institute's confirmation. The number of test points for each workshop should not be less than 3.

4. String inverters and other electrical equipment should be installed on the roof parapet or on separate supports, and a sunshade/rain canopy should be installed.

5. When laying rooftop cable trays near the array, they should be fixed on supports composed of clamps and angle steel. Cable tray covers should be secured with cable ties. The specific location and fixing method will be determined by on-site construction adjustments, but the distance from the roof surface must not be less than 100mm.

VIII. Power Cable Laying

1. The connecting cables for the components in this project use PV1-F-1kV-1+4mm: photovoltaic-specific cables. The AC low-voltage system from the string inverter output to the combiner box uses ZA-YJV22-0.6/1kV cables.

2. The dedicated photovoltaic (PV) cable from the PV array to the inverter is fixed below the PV modules. At passageways, the cable is protected by galvanized steel conduit (DN32). For AC cables from the inverter to the grid-connected metering cabinet, cable trays are used on the roof and walls, while conduits are used on the ground (existing passageways). The bending radius of the AC cable is not less than 15 times the cable's outer diameter. All cable sections between the inverter inlet/outlet and the cable tray must be protected by armored corrugated conduit.

IX. Lightning Protection

1. Lightning protection in this project aims to avoid impacting the solar panels' exposure to sunlight and ensure they are protected from direct lightning strikes. All metal mounting brackets and cable trays will be connected by bolts or a grounding grid composed of hot-dip galvanized steel (-40*4).

2. Each string inverter and low-voltage GGD cabinet will be equipped with a Class 1 surge protector.

3. All metal objects used in the lightning protection grounding system must be reliably welded. If welding is difficult, other feasible methods may be used, but they must comply with current national standards.

4. To prevent lightning surge intrusion, all metal sheaths and copper conduits of cables entering and exiting the building must be reliably connected to the grounding system.

X. Grounding

1. A grounding grid of -40x4 galvanized steel (galvanized layer thickness not less than 65um) will be used and connected to the steel structure and the steel columns (beams) of the photovoltaic brackets. The measured grounding resistance should not exceed 4Ω (if the solar panels have specific grounding resistance requirements, the lower of the two values will be used). 2. Stainless steel lightning protection conductive sheets or BVR-1x6mm² wires are used for equipotential bonding between the component frames. Each photovoltaic array has at least two points reliably connected to the grounding grid. The string inverters are connected to the grounding grid using BVR-1x16mm² yellow-green cables.

2. The purlins of the component support are grounded using galvanized flat steel connections, secured with self-tapping screws, and then connected to the grounding electrode via the grounding flat steel. For details on the lightning protection grounding device construction, please refer to the "Building Electrical Installation Engineering Drawings" for the construction roof lightning protection device construction diagram.

3. Normally non-energized metal parts of the electrical equipment, such as the metal casing of string inverters and cable racks, are electrically connected to the grounding device as close as possible. Cable ladders are connected to the horizontal grounding grid every 20mm using BVR-1x16mm². The location can be adjusted appropriately according to the actual site conditions, as long as it meets the relevant grounding specifications and construction standards for ladders.

4.The location of the grounding wire can be adjusted appropriately as needed. The grounding device should be fabricated and constructed simultaneously with the photovoltaic array support.

5.Galvanized flat steel welds should use lap joints. The lap length of the galvanized flat steel should be twice its width. For the connection method between the new grounding wire and the existing lightning protection strip around the building, please refer to the "Building Installation Engineering Construction Drawings" DQ13.

XI. Construction Instructions

1. The photovoltaic frame uses hot-dip galvanized supports.

2. The photovoltaic (PV) modules to the string inverter use PV1-F-1x4m DC cables, laid along the purlins of the PV module brackets (cables not laid within the purlins should be protected by carbon fiber corrugated pipes or galvanized steel pipes).

3.At crossings between adjacent brackets, cables must be protected by carbon fiber corrugated pipes. The length of the corrugated pipes should facilitate construction, bundling, and fixing. Cables from PV modules to the inverter that need to cross maintenance access routes, and cables between rows of module brackets, should be laid using cable trays or underground using galvanized steel pipes.

4.The string inverter to the transformer substation uses Z[-YJV22-0.6/1kV AC cables, laid using cable trays and conduits (cables entering and exiting the inverter and combiner box should be protected by carbon fiber corrugated pipes). 4. All cables crossing construction roads within the site area must be protected by galvanized steel conduits.

5. After all cables are laid, they must be treated with fire-retardant coating according to the design drawings.

6. All battery modules with outer frames in the power generation area must be reliably connected to the supports via BVR-4mm² grounding wires. All module supports must be connected to the grounding grid via flat steel. To save steel, the support beams will be used for partial grounding grid connections. The outer edge of the grounding grid must be closed, with each corner rounded, and the radius of the rounded corners should be no less than 30m. The grid spacing of the grounding grid should not exceed a certain value. The horizontal burial depth of the grounding grid should, in principle, be no less than 0.8m, and the burial depth across roads should be no less than 10m-100m.

7. All electrical equipment in the array area must be grounded. The grounding grid should primarily use horizontal grounding electrodes, supplemented by a vertical grounding electrode artificial grounding grid. The steel reinforcement of the civil engineering metal foundation should be fully utilized as a natural grounding electrode. The outer edge of the grounding grid must be closed, and appropriate measures should be taken to ensure safe grounding during burial.

8. The parapet walls in this project are relatively low. Safety precautions must be taken during construction, and construction can only proceed after the safety measures have been inspected and approved.

Wiring Diagram of PV Grid Connection System