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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
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This standard was proposed by the China Electricity Council (CEC).
This standard is under the jurisdiction of National Technical Committee 550 on Electric Energy Storage of Standardization Administration of China.
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Test specification for electrochemical energy storage system connected to power grid
1 Scope
This standard specifies the test conditions, test equipment, test items and methods for electrochemical energy storage system connected to power grid.
This standard is applicable to electrochemical energy storage systems with rated power of 100 kW and above and energy storage time of not less than 15 min, and it may also apply to electrochemical energy storage systems with other power levels and energy storage time.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 12326 Power quality — Voltage fluctuation and flicker
GB/T 12706.1 Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um=1.2 kV) up to 35 kV (Um=40.5 kV) — Part 1: Cables for rated voltage of 1 kV (Um=1.2kV) and 3 kV (Um=3.6 kV)
GB/T 12706.2 Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um=1.2 kV) up to 35 kV (Um=40.5 kV) — Part 2: Cables for rated voltages from 6 kV(Um=7.2 kV) up to 30 kV(Um=36 kV)
GB/T 13729 Remote terminal unit equipment
GB/ T 14549 Quality of electric energy supply — Harmonics in public supply network
GB/T 15543 Power quality — Three-phase voltage unbalance
GB 21431 Technical code for inspection of lightning protection system in building
GB/T 24337 Power quality — Interharmonics in public supply network
GB/T 36547 Technical rule for electrochemical energy storage system connected to power grid
GB 50057 Design code for protection of structures against lightning
GB 50150 Electric equipment installation engineering — standard for hand-over test of electric equipment
DL/T 474.4 Guide for insulation test on site — AC voltage withstanding test
DL/T 620 Overvoltage protection and insulation coordination for AC electrical installations
DL/T 621 Grounding for AC electrical installations
DL/T 995 Testing regulations on protection and stability control equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
energy conversion efficiency
ratio of the energy output when the energy storage system is discharging at rated power to the energy input when it is charging at rated power during the same cycle, expressed as a percentage.
3.2
control precision
degree of stability of the output/input power control of the energy storage system when the output/input power varies according to its set value under steady operating state and is calculated according to Equation (1):
(1)
where,
δP — the control accuracy;
PM — the average value of active power in the second 15 s after each step is actually measured;
PS — the power set-point.
4 General provisions
4.1 The test scheme and corresponding safety precautions shall be prepared and developed before the test.
4.2 Each device of the electrochemical energy storage system can be connected to the power grid for site test only after the completion of field debugging.
4.3 The test contents of electrochemical energy storage system include: power grid adaptability test (including frequency adaptability test, voltage adaptability test and power quality adaptability test), power control test, overload capacity test, power quality test, protection function test, test of response time for charging and discharging, test of regulation time for charging and discharging, test of transfer time for charging and discharging, rated energy test, energy conversion efficiency test, etc. The electrochemical energy storage system connected to the power grid through the voltage level of 10 (6) kV and above shall also be tested in low voltage ride-through test, high voltage ride-through test and communication test.
4.4 Power grid simulation devices should be used for power grid adaptability test, and power grid fault simulation devices should be used for low voltage ride-through test and high voltage ride-through test.
4.5 Test results shall meet the requirements of GB/T 36547 or other relevant requirements, and form a corresponding test report.
5 Test conditions
5.1 Environmental conditions
The energy storage system is tested under the following environmental conditions:
a) Ambient temperature: 5°C ~ 40°C;
b) Ambient humidity: 15°C ~ 90°C;
c) Atmospheric pressure: 86 kPa ~ 106 kPa.
5.2 Basic conditions
The energy storage system shall meet the following requirements before the grid-connected test:
a) The lightning protection grounding device of the energy storage system shall meet the requirements of GB/T 21431, GB 50057 and DL/T 621.
b) The insulating strength of the energy storage system access point equipment shall meet the requirements of GB 50150. The AC and DC cable insulation of each circuit of the access point shall meet the requirements of GB/T 12706.1 and GB/T 12706.2.
c) The withstand voltage of energy storage system access point equipment shall meet the requirements of DL/T 474.4 and DL/T 620;
d) When the voltage fluctuation and flicker at the point of interconnection of the energy storage system meet the requirements of GB/T 12326, the voltage harmonic value meets GB/T 14549, the three-phase voltage unbalance degree meets GB/T 15543, and the harmonic ratio between voltages meets the requirements of GB/T 24337, the energy storage system shall be able to operate normally.
6 Test equipment
6.1 Test instruments and apparatus
The test instruments and apparatus shall meet the following requirements:
a) The test instruments and apparatus shall be qualified and within the validity period;
b) The accuracy requirements for test instruments and apparatus are shown in Table 1.
Table 1 Accuracy requirements for test instruments and apparatus
Name Accuracy class Remarks
Voltage sensor 0.5 (0.2) classa FS (Full scale)
Current sensor 0.5 (0.2) Classa FS (Full scale)
Thermometer ±0.5°C
Hygrometer ±3% Relative humidity
Electric energy meter Class 0.2 FS (Full scale)
Data acquisition device Class 0.2 Data bandwidth ≥ 10 MHz
The accuracy of power quality measurement is required to be 0.2.
6.2 Power grid simulation device performance for test
The power grid simulation device shall be able to simulate changes in voltage amplitude, frequency and phase of the utility grid and meet the following technical requirements:
a) The voltage harmonics on the side connected to the power conversion system shall be less than 50% of the allowable harmonic value in GB/T 14549;
b) The current harmonics on the side connected to the power grid shall be less than 50% of the allowable value of harmonics in GB/T 14549.
c) During the test, the steady-state voltage variation amplitude shall not exceed 1% of the nominal voltage.
d) The voltage deviation shall be less than 0.2% of the nominal voltage.
e) The frequency deviation shall be less than 0.01 Hz.
f) The three-phase voltage unbalance shall be less than 1% and the phase deviation shall be less than 3°.
g) For the power grid simulation devices whose neutral point is not grounded, the neutral point displacement voltage shall be less than 1% of the phase voltage.
h) The rated power (PN, the same below) shall be greater than the rated power of the electrochemical energy storage system.
i) Having the ability to perform regulation of ±0.1% of the rated frequency fN within one cycle.
j) Having the ability to regulate ±1% of the rated voltage UN within one cycle.
k) The step response and regulation time shall be less than 20 ms.
6.3 Performance of grid fault simulation devices for test
The power grid fault simulation device shall meet the following technical requirements:
a) The device shall be capable of simulating three-phase symmetrical voltage drop, phase-to-phase voltage drop, and single-phase voltage drop. The drop amplitude shall include 0% to 90%.
b) The device shall be able to simulate three-phase symmetrical voltage lifts, and the lift amplitude shall contain 110% to 130%.
c) The voltage step response and regulation time shall be less than 20 ms.
7 Test items and methods
7.1 Grid adaptability test
7.1.1 Frequency adaptability test
The frequency adaptability of the energy storage system is tested and the test wiring is shown in Figure 1. This test project shall simulate the changes in the line frequency with power grid simulation device. The test procedures are as follows:
a) Connect the energy storage system with power grid simulation device;
b) Set the energy storage system to operate in charging state;
c) Regulate the frequency of the power grid simulation device to the range of 49.52 Hz ~ 50.18 Hz. Within this range, properly select several points (at least 3 points and the critical point must be measured), and run continuously for at least 1 min. There shall be no tripping; otherwise the test will be stopped.
d) Set the energy storage system to run in discharging state, and repeat step c).
e) Connect the energy storage system to the power grid through 380 V voltage levels:
1) Set the energy storage system to operate in charging state, regulate the frequency of the power grid simulation device to the range of 49.32 Hz～49.48 Hz and 50.22 Hz～50.48 Hz, and reasonably select several points within this range (at least 3 points and critical points must be measured), and each point will run continuously for at least 4 s; respectively record the running state of the energy storage system and the corresponding actuation frequency and actuation time;
2) Set the energy storage system to run in discharging state, and repeat Step 1).
f) The energy storage system connected to the power grid through the voltage level of 10(6) kV and above:
1) Set the energy storage system to run in charging state, regulate the frequency of the power grid simulation device to the range of 48.02 Hz～49.48 Hz and 50.22 Hz～50.48 Hz, and reasonably select several points within this range (at least 3 points and critical points must be measured), and each point will run continuously for at least 4 s; respectively record that running state of the energy storage system and the corresponding action frequency and actuation time;
2) Set the energy storage system to run in discharging state and repeat Step 1);
3) Set the energy storage system to run in charging state, regulate the frequency of the power grid simulation device to 50.52 Hz, and run continuously for at least 4 s; record the running state of the energy storage system and the corresponding actuation frequency and actuation time;
4) Set the energy storage system to run in discharging state and repeat Step 3);
5) Set the energy storage system to run in charging state, regulate the frequency of the power grid simulation device to 47.98 Hz, and run continuously for at least 4 s; record the running state of the energy storage system and the corresponding actuation frequency and actuation time;
6) Set the energy storage system to run in discharging state, and repeat Step 5).
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General provisions
5 Test conditions
6 Test equipment
7 Test items and methods
