GB/T 47516-2026Safety requirements for solar trackers (English PDF)

4.1 Mechanical Structure Safety

4.1.1 Mechanical structural strength Reasonable design and construction should be adopted to ensure that it meets the requirements with appropriate reliability and economy within the specified design service life. It meets all functional requirements, possesses sufficient safety and corrosion resistance, and satisfies the ultimate limit state and normal service limit state.

4.1.2 Static wind load The solar tracker should be able to withstand static wind loads under wind pressures with a local return period of not less than 50 years. The static wind load requirements are as follows:

a) Static wind load applies to all arrays of solar trackers.

b) Static wind load requirements are independent of the wind protection strategy or tilt angle designed for the wind.

c) The static wind load calculation is based on the solar tracker's structural design, geometry, wind speed, safety factor, and the structure under evaluation. Wind load zones for components and connection nodes.

d) Static wind loads should be divided into two cases. balanced and unbalanced (acting on the component surface) loads, including wind pressure formula (1) and standard load. The calculation of formula (2) for load and formula (3) for torque of chord length and load region. The static wind load torque coefficient is shown in Figure 1. The calculation of substructure components and connection nodes should refer to the static wind load torque coefficient. 1) Connection between photovoltaic modules and purlins; 2) Connection between purlins and spindle; 3) Connections between spindles; 4) Connection between the main shaft and the column; 5) Connection between the spindle and the torsion fixed point (usually a rotary drive or a linear drive).

4.1.3 Dynamic wind load Based on static wind loads, dynamic wind loads caused by wind-induced vibration should be considered, using aeroelastic wind tunnel reports and related dynamic data. The wind load factor serves as the design basis to ensure that the structure will not suffer aeroelastic stability failure.

4.1.4 Torsional stiffness The solar tracker should have minimum torsional stiffness to ensure its stability when operating at low wind speeds. Apply a [condition] to the longest portion between the torsion fixation point and the free end of the solar tracker, or the longest portion between two torsion fixation points. The minimum torsional stiffness is determined by a uniform torque (unbalanced load), and the resulting torsional deformation (torsion of the torsional foot from the unloaded position) should not exceed 10°. The magnitude of the uniform torque is proportional to Lref2 (the square of the chord length), as shown in formula (4).

4.1.5 Snow Load The design value of snow load shall comply with the provisions of GB 50009, and the basic snow load shall be determined based on a return period of at least 25 years.

4.1.6 Seismic Load In seismic fortification areas, the impact of seismic action on the structure should be considered, and the structural design should comply with the provisions of GB/T 50011.

4.1.7 Limiting Mechanism The limit mechanism is an important function of the solar tracker and should meet the following requirements.

a) The control software simulates the closing and opening of the limit switch to trigger a warning message.

b) Close the limit switch again, and the warning message will disappear.

c) There are usually three types of limit switches. 1) Soft limit switch, implemented by setting position parameters in software; 2) Hard limit switches, implemented by position sensors mounted on the structure; 3) Mechanical limit switch, implemented by adding an additional mechanical limit mechanism.

4.2.1 Protection against electric shock

4.2.1.1 General Rules All electrical systems and components of the solar tracker should be protected against electric shock in the following ways. --Direct contact protection; --Indirect contact protection.

4.2.1.2 Direct Contact Protection Direct contact with live parts should be prevented by using an enclosure or barrier and insulation of the live parts. When direct contact does occur, protective measures must be taken to ensure... Ensures that contact with live parts will not cause the risk of electric shock. Protective impedance isolates faults and limits overcurrent.

4.2.1.3 Indirect Contact Protection Indirect contact protection is achieved through equipotential bonding or local equipotential bonding, and double or reinforced insulation.

4.2.2 Overcurrent Protection If the current in any circuit of the solar tracker controller may exceed the rating of any component or the current carrying capacity of any wire, an overcurrent protection device should be provided. Flow protection device.

4.2.3 Insulation withstand voltage The current-carrying components and external parts of the solar tracker controller shall be adequately insulated and shall meet the requirements of

9.6.5 of GB/T 29320-2024. Insulation requirements.

4.2.4 Lightning protection grounding The lightning protection grounding of the solar tracker shall meet the requirements of

9.6.4 of GB/T 29320-2024.

4.2.5 Motor overheating The motor should have overheat protection, which can be achieved in the following ways. --Overcurrent protection; --Over-temperature protection; --Block protection.

4.2.6 Power outage

4.2.6.1 In the event of power interruption or voltage drop, undervoltage protection should be provided to ensure that the normal operation of the solar tracker is not damaged.

4.2.6.2 After the voltage is restored or the input power is connected, the automatic or accidental restart of the solar tracker should be prevented.

4.2.7 Short circuit It should have short-circuit protection measures so that the controller will not malfunction or be damaged, nor will it cause electric shock to the operator, if the field operation terminal is connected incorrectly. harm.

4.2.8 Control Circuit The nominal value of the control circuit voltage should be consistent with the normal operating mode voltage of the control circuit, and should include the following requirements.

a) For circuits with an AC frequency of

50 Hz, the nominal voltage should not exceed 230 V.

b) The nominal voltage of the DC control circuit should not exceed 36 V.

c) The control circuit should have overcurrent protection.

4.2.9 Control

4.2.9.1 Startup 4.2.9.1.1 The startup function should be activated by powering on the relevant circuits. 4.2.9.1.2 If multiple control devices are required for startup, each control device shall have a separate manual startup device. 4.2.9.1.3 The startup conditions are. --All conditions for the operation of the solar tracker should be met; --All start-up control devices should be in the closed position; --All start control devices should be started simultaneously (excluding manual start devices).

4.2.9.2 Stop 4.2.9.2.1 The solar tracker should have stop functions of stop category 0, 1, or 2, as follows:

a) Stop Category

0.Uncontrolled Stop -- Should be stopped by immediately disconnecting the power supply to the drive;

b) Stop Category

1.Controlled Stop - Stop the movement of the solar tracker while maintaining drive power during the stopping process. The drive is stopped by the available power, and the power is cut off after it stops;

c) Stop Category

2.Controlled Stop -- The drive should be powered during the stop and continue to be powered after the stop. Note

1.When the power supply is disconnected, select stop category 0 during operation. Note

2.When the stop function is activated, all solar tracker functions except motion must be stopped. Note

3.Disconnecting power means removing the power required to generate torque or force, which can be achieved by disengaging the clutch, disconnecting, cutting off, or by electronic means. 4.2.9.2.2 Stop functions should take precedence over related start functions. 4.2.9.2.3 In the case of multiple controllers in an independent unit, a stop command from any controller shall be valid.

4.2.9.3 Measures to be taken when a failure occurs 4.2.9.3.1 Measures should be taken to minimize the danger or damage caused by control system failure or interference. For example. control system The system retains memory via battery power; therefore, measures should be taken to prevent hazards caused by battery failure, undervoltage, or removal. Access permissions required. Manage access to code and tools to prevent unauthorized or unintentional changes to memory. 4.2.9.3.2 Measures to reduce the risk of failure include, but are not limited to.

a) The control circuit has protection functions;

b) Stop by power failure;

4.3 Functional Safety

4.3.1 Grounding Continuity All control and mechanical components of the solar tracker should have effective connections. The connection resistance of the following connection nodes needs to be evaluated (connection...). (Connection resistance not greater than 0.1 Omega)

a) Connection between photovoltaic modules and purlins;

b) Connection between purlins and main shaft;

c) Connections between spindles;

d) Connection between the spindle and the torsion fixing point;

e) Connection between the control unit and the spindle.

f) Connection between the main shaft and the column; The solar tracker is grounded via a pillar.

4.3.2 Communication The communication of the solar tracker shall comply with the provisions of GB/T 31366.

4.3.3 Electromagnetic Compatibility It should comply with the provisions of

9.5 in GB/T 29320-2024.

4.4 Protection Level

4.4.1 Protection against human contact with hazardous parts and against the ingress of solid foreign objects and water (IP code) According to GB/T 4208, the protection level of the control box shall not be lower than IP54, and the protection level of the motor shall not be lower than IP65.

4.4.2 Protection against mechanical impact (IK code) The impact level of the controller housing should not be lower than IK08 in GB/T 20138.

4.5 Corrosion Protection The corrosion protection of the steel structure of the solar tracker should meet the following requirements. --The design should facilitate inspection and cleaning. --The anti-corrosion measures adopted for the steel structure of the solar tracker should be comprehensively judged based on the environmental conditions in which the equipment is used, such as atmospheric corrosion level and soil corrosion. The atmospheric corrosion rating standards and recommended methods and testing standards for anti-corrosion measures of steel structures are based on GB/T 19292.1 and GB/T 19292.2. GB/T 30790 (all parts). --For steel structure corrosion protection, hot-dip galvanizing or higher-performance anti-corrosion coatings (such as zinc-aluminum-magnesium oxide) or other anti-corrosion materials should be used. The thickness of the anti-corrosion coating should be... According to GB/T 13912, GB/T 2518, and YB/T 4761. --Aluminum alloy materials can be coated using methods such as anodizing, with the coating thickness conforming to GB/T 5237.2, GB/T 5237.3, and GB/T 5237.5. --When aluminum alloy materials come into contact with or are fastened to other metal materials besides stainless steel, or to acidic or alkaline non-metallic materials. Isolation measures should be taken to prevent electrochemical corrosion.

4.6 Fire prevention Solar trackers should utilize appropriate materials, components, and structural design to reduce the risk of fire and flame spread. There are two main types. method.

1.Select and use components, wiring, and materials that reduce the likelihood of ignition and flame spread; use fireproof covers when necessary. The flammability rating is not lower than V-2 or HB.

2.Open circuits or short circuits in relevant components will adversely affect supplementary and reinforced insulation. Only in Method 2... The fault test will not cause the component to catch fire. The solar tracker does not need to undergo a fault test if the temperature reaches the ignition point or other signs of fire. Use a fireproof cover.

5.1 Static Wind Load Test

5.1.1 Test Procedure Follow the procedure below.

a) The standard values Fn and My calculated according to formulas (2) and (3) are applied to the actual load combination to obtain the design values F and M is used to determine the load test size for the solar tracker.

b) The moment load is divided into a quarter-discrete chord-width (Lref/4) region. Remove the object from one side and add it to the other side to produce... An unbalanced load is generated, as shown in Figure

2.The load is repeatedly transferred from one side to the other in an unbalanced direction.

5.3 Limit Test

5.3.1 Test Procedure Follow the procedure below.

a) Close the limit switch in the tracking limit direction, then open the switch to perform the simulation. A warning message will be displayed at this time.

b) Close the limit switch again; the warning message will then disappear.

c) Trigger the solar tracker braking at the preset stop position and display a warning message;

b) to eliminate the warning and run the solar tracker in the opposite direction.

5.3.2 Acceptance Criteria The limit protection is triggered, but the normal operation of the solar tracker will not be affected after it is restored.

5.4 Overcurrent Protection Test

5.4.1 Test Procedure According to GB/T 16895.23.

5.4.2 Acceptance Criteria The solar tracker should have overload protection to ensure it can resume operation.

5.5.1 Test Procedure Sections

14.7.4.3 of GB/T 29320-2024 apply.

5.5.2 Acceptance Criteria The test leakage current passed the set value, and the controller did not break down.

5.6 Lightning protection grounding test

5.6.1 Test Procedure Use a multimeter to measure the connection between the surge protector grounding wire, safety grounding wire, metal casing of electrical cabinet or control box, etc., and the grounding terminal block. Electrical connectivity between the various metal components of the solar tracker.

5.6.2 Acceptance Criteria The test results meet the requirements of

4.2.4 and are therefore deemed qualified.

5.7 Motor overheat protection

5.7.1 Test Procedure According to UL 1004-1-2020.

5.7.2 Acceptance Criteria The criteria for acceptance are as follows:

a) The temperature of the motor casing should not exceed 125°C;

b) The temperature at any point inside the junction box should not exceed 60 °C.

5.8 Power Outage Recovery Test

5.8.1 Test Procedure Follow these steps.

a) Operate the solar tracker in automatic mode;

b) Disconnect all power to the solar tracker;

c) Restore power to the solar tracker and verify that the tracker restarts automatically.

5.8.2 Acceptance Criteria After power is restored, the solar tracker should not restart automatically or unexpectedly; it should be started manually.

5.9 Short-circuit test

5.9.1 Test Procedure Reversing the polarity of the controller's power input, motor output, and battery output terminals during connection ensures safe operation of the controller. Shutdown.

5.9.2 Acceptance Criteria Any reverse connection configuration should not result in an electric shock hazard.

5.10 Emergency Stop Test

5.10.1 Test Procedure Follow these steps.

a) When the solar tracker is operating in automatic mode, press the emergency stop button on the controller;

b) Release the emergency stop button after 1 minute.

5.10.2 Acceptance Criteria The results are as follows:

a) The solar tracker should come to a complete stop after the emergency stop device is pressed;

b) After the emergency stop is released, the solar tracker should resume automatic operation.

5.11.1 Test Procedure According to the provisions of

14.7.2 in GB/T 29320-2024.

5.11.2 Acceptance Criteria The connection resistance is less than 0.1 Omega.

5.12 Communication Test

5.12.1 Test Procedure Follow the procedure below.

a) Use a host computer to send security protection commands to the solar tracker through the communication system, and record the execution status of the solar tracker;

b) Use a host computer to monitor the operating status of the solar tracker through the communication system and record the status information of the solar tracker.

5.12.2 Acceptance Criteria It meets the requirements of 4.3.2.

5.13.1 Test Procedure

5.13.1.1 Launch Test According to GB 4824.

5.13.1.2 Immunity Test Immunity tests shall be conducted in accordance with GB/T 17626.2, GB/T 17626.3, GB/T 17626.4, GB/T 17626.5, and GB/T 17626.6. The provisions of GB/T 17626.8 and GB/T 17626.11.