Views: 0 Author: Devin Chen Publish Time: 2025-09-30 Origin: Site
Today, under the situation of energy shortage and strict control of carbon emission policies, Residential energy demand is increasingly inclined to photovoltaic power generation. Residential energy or household energy storage systems are increasingly entering ordinary people's homes. In household energy storage systems, a critical DC switching device called the high-voltage DC contactor plays a vital role. Installed within the high-voltage box, this core component serves as both the electrical connection and protective mechanism between battery clusters and the system. The performance of this high-voltage DC contactor directly determines whether the entire household energy storage system can operate safely, reliably, and maintain long-term stability.
In a household energy storage system, two high-voltage DC contactors are usually used for:
• Positive circuit contactor: controls the connection between the battery cluster positive and the system
• Negative pole circuit contactor: controls the connection between the battery cluster negative pole and the system
Some systems also add a pre-charge contact to pre-charge the capacitor before the main contact is closed to prevent surge currents. Therefore, the common configuration is: 2 ~ 3 contactors, the specific number depends on the system design.
At present, the energy storage system of household PV generally adopts the system voltage of 1000Vdc. In order to ensure the long-term safe and reliable operation of the energy storage system, the leading customers in the industry have put forward a series of requirements for the HVDC contactors used in the high-voltage box, which are summarized as follows:
Chart of Summary of experiments
No. | Test Item | Reference Standard |
1 | Basic Performance Test | GB/T 21711.7-2018 |
2 | Auxiliary Contact Resistance ≤0.1Ω（@2A） | GB/T 21711.7-2018 |
3 | Glow-Wire Test | GB/T 14048.1-2012 7.1.2.2, GB5169.10, GB5169.12 |
4 | Terminal Mechanical Strength Test | GB/T 14048.1-2012 8.2.4.2 |
5 | Enclosure Mechanical Strength | GB/T 14048.1-2012 8.2.4.2 |
6 | Impulse Withstand Voltage 8KV±3%。 | GB/T 21711.7-2018 4.10 |
7 | Temperature Rise | GB/T 14048.1-2012 8.3.3.3 |
8 | Making and Breaking Electrical Life | UL508-1999 |
9 | Making and Breaking Electrical Life | UL508-1999 |
10 | Making and Breaking Electrical Life | UL508-1999 |
11 | Auxiliary Contact Electrical Life | UL508-1999 |
12 | Mechanical Life 500K cycles | GB/T 21711.7-20184.31 |
13 | Mechanical Life at High Temperature | GB/T 21711.7-20184.31 |
14 | Mechanical Life at Low Temperature | GB/T 21711.7-20184.31 |
15 | Current Carrying Capacity | GB/T 14048.1-2012 8.3.3.3 |
16 | Ultimate Breaking Capacity | UL508-1999 |
17 | Coil Parameters at High Temperature | GB/T 21711.7-2018 4.13, GB/T 21711.7-2018 4.14 |
18 | Coil Parameters at Low Temperature | GB/T 21711.7-2018 4.13, GB/T 21711.7-2018 4.14 |
19 | Low Temperature Test | GB/T28046.4-2011 5.1.1 |
20 | High Temperature Test | GB/T28046.4-2011 5.1.2 |
21 | Damp Heat, Cyclic Test | GB/T28046.4-2011 5.6 |
22 | Mechanical Vibration | GB/T28046.3-2011 4.1.2.7 |
23 | Mechanical Shock | GB/T28046.3-2011 4.2 |
24 | Impact Strength | GB/T28046.3-2011 4.2 |
25 | Long-Term Load Test | GB/T 14048.1, GB/T14048.4 |
26 | Long-Term High Temperature & Humidity Storage | GB/T28046.4 5.6 |
27 | Thermal Shock Test (High-Low Temperature Cycling) | GB/T2423.22-2012 |
28 | Salt Spray Test | GB/T 2423.17-2008 |
29 | Rated Short-Circuit Breaking Capacity | GB/T 14048.1-2012 7.2.5 |
In the current market, most brands of 100A series high-voltage DC contactors, especially epoxy sealed DC contactors, have an ideal electrical life at 750Vdc, but when it comes to 1000Vdc voltage, their electrical life performance drops sharply, as shown in the figure below.
Many brands on the market merely claim their products achieve 1000V DC or even 1500V DC voltage ratings, yet fail to specify electrical lifetime. When evaluating DC contactors' performance, only talk voltage parameters is insufficient and may even mislead users. The true performance of DC contactors—particularly their electrical lifetime—should be assessed through comprehensive testing of Voltage, Current, and the qualified Cycles achieved during making and breaking.
For information on the relationship between Ui and Ue and how to distinguish the performance of DC contactors, see the previous article:
In order to meet the performance requirements of customers in the household energy storage industry for HVDC contactors, we have developed a series of "211" dedicated products as follows:
The core performance of the "211" series of special products is as follows:
Below is our UL certification information:
As can be seen from the table, the "211" series products have a 100A electrical lifetime 1000 times on and off at 1000Vdc voltage, while many brands can only achieve about 100 times under the same circumstances, and the performance is 1/10 of ours.
The above "211" series high-voltage DC contactors, which special on household energy storage, have been widely used in the equipment of several large customers in the energy storage industry.
How the “211” series product is designed to have such excellent high voltage lifetime will be discussed in a later article.
Product selection refers to the following table, other aspects such as wire length, terminal and other special requirements can be customized.
For the relevant test items in the chart of summary of experiments, if you are interested, please contact me for them.
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#PVInverter #Inverter #PV
