NB/T 10204-2019Technical requirements for interface equipment of distributed PV generation system connected to low voltage power distribution networks (English PDF)

3.1 Distributed photovoltaic generation

Constructed near the user's site, the operation mode is based on the user's spontaneous self-use, the excess power is connected to the Internet, and the balance adjustment is used on the power distribution system side. Characteristic photovoltaic power generation facilities.

3.2 Interface equipment

Distributed photovoltaic power generation system is connected to the integrated device of low-voltage power distribution network, with interruption, protection, acquisition, monitoring, communication, storage, etc Features.

5.1 Environmental conditions

The device should work normally under the following climatic conditions.

a) Ambient temperature. -10°C~ 55°C (indoor type), -25°C~ 70°C (outdoor type);

b) Relative humidity. <=95% (25°C);

c) Altitude. below 2000m;

d) Seismic resistance. horizontal acceleration 0.30g, vertical acceleration 0.15g;

e) Pollution degree. not exceeding the level 3 specified in GB/T 16935.1-2008;

f) Degree of protection. indoor type shall not be lower than IP20 specified in GB/T 4208; outdoor type shall not be lower than IP54 specified in GB/T 4208.

5.2 Conditions for access to the grid

The device should be able to work normally under the following conditions of access to the power grid.

a) Rated frequency of power grid. 50 Hz, allowable deviation ±1Hz;

b) Rated power grid voltage. three-phase 380V or single-phase 220V. The allowable deviation of 220 V voltage is -15%~10% of the rated voltage, The allowable deviation of 380V voltage is -10%~10% of the rated voltage.

6.1 Structure and appearance requirements

The device structure should meet the requirements specified in 8.1.1 of GB/T 7251.1-2013. The structure and appearance of the device should also meet the following requirements.

a) The box body of the device should be firm and flat, the surface should be smooth and flat, and the color of the coating should be uniform without obvious color difference and glare.

The surface should be free of defects such as sand, rust, wrinkles and flow marks.

b) The panel of the device cabinet should be flat, and the text and symbols should be clear, tidy, standardized and correct.

c) Signs, signs and markings should be complete and clear.

d) Various door locks and switches should be easy to operate, flexible and reliable.

e) The device should be marked with a warning sign indicating that the metal parts in the box are live.

6.2 Grounding

The conductive box parts in the device should be effectively grounded. The resistance from any point in the grounding circuit to the grounding terminal should not exceed 0.1ohm.

6.3 Mechanical requirements

The device should be able to withstand the mechanical vibration and shock requirements specified in DL/T 478, and be suitable for the normal transportation and operation of the device.

6.4 Insulation performance

6.4.1 Insulation resistance

The insulation resistance between the conductive circuit of the device and the ground should not be less than 0.5Mohm.

6.4.2 Insulation strength

The device should be able to withstand a power frequency AC voltage or equivalent DC voltage with a frequency of 50 Hz and a duration of 1 min. During the test, ensure that there is no breakdown.

No arcing, leakage current less than 20 mA; the voltage level of the dielectric strength test should meet the requirements of Table 1.

Note: In principle, the media strength of the whole machine should be tested once according to the above indicators. If necessary, the test can be repeated, and the test voltage is 75% of the specified value.

6.4.3 Clearance and creepage distance

The electrical clearance and creepage distance should meet the requirements of Table F.7 and Table F.4 of GB/T 16935.1-2008. The minimum creepage distance should not be less than in the air Minimum electrical clearance.

6.5 EMC performance

6.5.1 Electrostatic discharge immunity

The device should be able to withstand the electrostatic discharge immunity test of test level 3 specified in GB/T 17626.2-2006, and the test results should meet

GB/T 17626.2-2006 Chapter 9 Class b requirements.

6.5.2 Radio frequency electromagnetic field radiation immunity

The device should be able to withstand the radio frequency electromagnetic field radiation immunity test of test level 3 specified in GB/T 17626.3-2016, and the test results should Meet the requirements of category a in Chapter 9 of GB/T 17626.3-2016.

6.5.3 Electrical fast transient pulse group immunity

The device should be able to withstand the electrical fast transient pulse group immunity test of test level 3 specified in GB/T 17626.4-2008, the test results It shall meet the requirements of category a in Chapter 9 of GB/T 17626.4-2008.

6.5.4 Surge (impact) immunity

The device should be able to withstand the surge (impact) test specified in GB/T 17626.5-2008 (apply a 1.2/50us surge signal to the power port, Line-to-line ±1 kV, line-to-ground ±2 kV), the test results should meet the requirements of category b in Chapter 9 of GB/T 17626.5-2008.

6.5.5 Radio frequency conducted immunity

The device should be able to withstand the radio frequency conducted immunity test of test level 3 specified in GB/T 17626.6-2008, and the test results should meet Type a requirements in Chapter 9 of GB/T 17626.6-2008.

6.5.6 Power frequency magnetic field immunity

The device should be able to withstand the power frequency magnetic field immunity test of test level 3 specified in GB/T 17626.8-2006, and the test results should meet Class a requirements in Chapter 9 of GB/T 17626.8-2006.

6.5.7 Ring wave immunity

The device should be able to withstand the ring wave immunity test of test level 3 specified in GB/T 17626.12-2013, and the test results should meet

GB/T 17626.12-2013 Chapter 9 Class A requirements.

7.1 General requirements

The device should have grid connection/exit, restore grid connection, undervoltage protection, overvoltage protection, overcurrent protection, data acquisition, data storage, communication Function, should have reverse power protection, human-computer interaction function.

7.2 Power adaptability

The power input voltage of the device should be AC220V/AC380V, the allowable deviation is -20%~20%; the frequency is 50Hz, and the allowable deviation is -2.5Hz~1.5Hz.

7.3 Control and protection functions

7.3.1 Grid connection/exit function

The device should have the grid-connected/exit function, which is realized by the switch element in the device, and the switch element meets the following requirements.

a) There should be obvious instructions for grid connection/exit;

b) Switchgear with reverse connection capability of power supply and load should be used. When switchgear without reverse connection capability is used, the power supply The terminal should be connected to the grid side;

c) The switching element should have a short-circuit quick-break function.

7.3.2 Restore grid connection function

The device shall have the function of automatic recovery and grid connection. The delay time for automatic recovery and grid connection can be set.

7.3.3 Undervoltage protection function

The device shall have undervoltage protection function. When the grid voltage is less than the set voltage, the device should disconnect from the grid within the set time.

7.3.4 Overvoltage protection function

The device shall have an overvoltage protection function. When the grid voltage is greater than the set voltage, the device should disconnect from the grid within the set time.

7.3.5 Overcurrent protection function

The device shall have an overcurrent protection function. When the grid connection point current is greater than the set current, the device should be disconnected from the grid within the set time Connection.

7.3.6 Reverse power protection function

The device should have reverse power protection. When it is monitored that the power of the grid-connected point is reversed to the grid, the device should be disconnected from the grid within the set time Connection.

7.4 Data collection and storage

7.4.1 Data Collection

The data sampling interval should not be greater than 5 minutes, and the collected information should at least include the following.

a) Electrical analog quantities. voltage, current, frequency, active power, and reactive power;

b) Status quantity. switch status, fault information.

7.4.2 Data Storage

The data storage function requirements of the interface device are as follows.

a) The data storage interval should not be greater than 5 minutes, and the stored data information includes the amount of data collected;

b) The maximum storage time of historical data is more than 3 months, and the storage time of historical data of device power failure is at least 1 year. Convenient to transfer or export.

7.5 Communication function

The interface device should have a communication interface with the photovoltaic power generation system and the information acquisition and control platform of the distribution network, and meet the following requirements.

a) The interface device has at least one interface to communicate with the photovoltaic power generation system;

b) The interface device has at least one interface to communicate with the power grid;

c) The interface device should have a wireless communication interface, which can realize the user's remote monitoring function.

7.6 Human-computer interaction

The interface device should have a human-computer interaction function, and the human-computer interaction interface can display the device status, communication status, and collected information.

9.1 Inspection classification

Device inspection is divided into type inspection, factory inspection and on-site inspection, and the inspection items shall meet the requirements of Table 2.

9.2 Type inspection

Type inspection should be carried out in one of the following situations.

a) Before new product identification;

b) When there are major changes in structure, material, process, firmware, etc., which may affect product performance;

c) When the product has been stopped for more than 1 year and then resumed production.

The type inspection qualification shall comply with the regulations of DL/T 478.

9.3 Factory inspection

Before leaving the factory, each device shall be inspected by the manufacturer's quality inspection department and confirmed to be qualified before leaving the factory. Factory qualified after inspection The device should have a product certificate that proves that the device is qualified.

9.4 Site inspection

After the device is installed on site and before it is put into operation, it should be tested on site.

10.1 Logo

10.1.1 Each device must be provided with a long-lasting and clear logo or nameplate on a prominent part of the chassis, the logo is as follows.

a) Product name and model;

b) The full name and trademark of the manufacturer;

c) Main parameters;

d) External terminal and interface mark;

e) Factory date and serial number.

10.1.2 There are receipt and delivery signs, packaging storage and transportation signs and warning signs on the outer packaging of the device, which shall be implemented in accordance with the relevant regulations of GB/T 191.

10.2 Packaging

10.2.1 The technical documents supplied with the product include.

a) Installation instructions;

b) Product instruction manual;

c) Technical indicators and parameters;

d) Product quality certificate;

e) Warranty card;

f) User opinion survey form.

10.2.2 Product packaging should comply with the relevant regulations of GB/T 13384.

10.3 Storage

The device should be placed in the original packaging box, stored in air circulation, ambient temperature -25°C~55°C, relative humidity not more than 85%, no harmful Storehouses containing gases, flammable and explosive materials and corrosive materials, and should not be subjected to strong mechanical vibrations, shocks and strong magnetic fields.

10.4 Transportation

The transportation of the device should meet the requirements of GB/T 4798.2. Among them, the transportation environment temperature is -25°C~70°C, and the relative humidity is <=85%.