High-Voltage Contactors
High-voltage contactors are widely used in electric vehicles, EV charging station, energy storage system as well as solar and wind equipments.
Advanced Features of our High-Voltage Contactors
High safety and reliability
Compact structure, low working noise
Bi-directional design
Auxiliary contacts
Flexible installation requirement
Build-in energy saving board, PWM coil
High-Voltage Contactor Portfolio
High-Voltage Contactor ZJQ250
250A continuous current
Rated voltage:12-450Vdc
coil voltage:9-36Vdc
High-Voltage Contactor EVQ10
10A continuous current
Rated voltage:12-900Vdc
coil voltage:12Vdc/24Vdc
High-Voltage Contactor EVQ30
30A continuous current
Rated voltage:12-900Vdc
coil voltage:12/24/48/72Vdc
High-Voltage Contactor ZJQ100
100A continuous current
Rated voltage:12-450Vdc
coil voltage:12Vdc/24Vdc
High-Voltage Contactor ZJQ150
150A continuous current
Rated voltage:12-450Vdc
coil voltage:9-36Vdc
High-Voltage Contactor ZJQ50
50A continuous current
Rated voltage:12-450Vdc
coil voltage:12Vdc/24Vdc
High-Voltage Contactor EVQ200
200A continuous current
Rated voltage:12-900Vdc
coil voltage:12/24/48/72Vdc
High-Voltage Contactor EVQ250
250A continuous current
Rated voltage:12-900Vdc
coil voltage:12/24/48/72Vdc
High-Voltage Contactor EVQ600
600A continuous current
Rated voltage:12-900Vdc
coil voltage:9-36Vdc
High-Voltage Contactor EVQ400
400A continuous current
Rated voltage:12-900Vdc
coil voltage:9-36Vdc
High-Voltage Contactor EVH40
40A continuous current
Rated voltage:12-1500Vdc
coil voltage:12/24Vdc
High-Voltage Contactor EVH300
300A continuous current
Rated voltage:12-1500Vdc
coil voltage:12/24Vdc
High-Voltage Contactors Lineup
6 Tips to find reliable high-voltage contactors
*High Voltage Resistance
It’s required to withstand high working voltage and reliable connection and disconnection in high current and high voltage load
*High Load Carry Capacity
High-voltage contactors should have strong load-resisting capacity, while the current will reach to 200A and 300A in new energy vehicels, it also requires instantaneous overload capacity
*Impact Resistance
High-voltage contactors not only required to have basic function of withstanding high voltage and carrying sufficient current, but also resist the impact of huge inrush current of the capacitive load at the moment of closing. The hazard of this inrush current will cause to contact stick/melting
*Strong Arc Extinguishing Ability
Arc is an inevitable problem in the process of DC high voltage switching. Hydrogen and Nitrogen are filled in the chamber of contact to support rapid arc extinguishing
*Qualified certifications
Please also take quality certification into consideration, all of our high voltage contactors are produced under IATF16949 and ISO9001, passed CCC, CE and many are UL certified
*Strong Breaking Capacity
In an emergency of short-circuit, instantaneous current in the circuit suddenly rises, which requires the high voltage contactor to cut off the circuit under high current safely. Hence, high voltage contact must have good impact resistance and anti-adhesion ability
Contact with us for more information. Our experienced R&D team will help to customize products to meet your specific requirements.
INSIGHTS OF HIGH-VOLTAGE CONTACTOR MANUFACTURING
The High voltage DC contactors which used in high voltage DC application have the basic characteristics of high voltage and high current, so they need to have high reliability and high insulation voltage. Different from ordinary industrial contactor products, its manufacturing also requires professional manufacturing processes such as vacuuming, gas filling, pressure sealing, and intelligent control, which requires high design technology and manufacturing technology.
In order to choose the best type of contactor, it is important for you to know the major basics and the mechanism that is taking place in the system. Details of following areas related to contactor have been described below: Design of high-voltage contactors, raw materials for high-voltage contactors, type of filling, types of sealing, production equipment, key technology, testing equipment, performance of high-voltage contactors, and future of contactors.
Design of high-voltage contactors
Raw Materials for high-voltage contactors
Manufacturing equipment for high-voltage contactor
Gas-filled and Regular DC Contactors
Epoxy sealed and Ceramic sealed Contact Chambers in a Contactor
Hardware Components of Electronics: Main Contactor and Pre-charged Contactor
Design of high-voltage contactors
It includes environmental adaptability design, safety and reliability design.
Environmental adaptability design
Different from general industrial contactor, the environmental conditions of high voltage contactors have more stringent requirements for the adaptability. It must meet the basic conditions of a wide temperature range, high protection level, and high vibration resistance.
1)High and low temperatures design: high voltage contactors need to meet the temperature requirements of electric vehicles and charging piles (stations) for normal use in extreme weather. Product storage environment temperature: -55~+125℃, normal working environment temperature is -25~+40℃, under extreme conditions, environment temperature is -40~+85℃,
2) Protection level design: high voltage contactors need to meet the normal work under severe environmental conditions and the normal use under rain and dust environment. It completely prevents dust from entering, meets the short-term water immersion requirements, and the protection level reaches IP67.
3) Anti-vibration performance design: high voltage contactors need to have strong vibration resistance and impact resistance. To meet the special needs of vehicles used in various road conditions and vibrations.
Safety and reliability design
Safety and reliability are the first and most critical element to measure the high voltage DC contactor of electric vehicles, which is mainly reflected in the arc extinguishing capacity and insulation voltage.
DC arc has no zero crossing point and it is difficult to extinguish the arc after arcing. The product structure is designed as a double-breakpoint direct-acting movement form. And the arc extinguishing technical means of filling compressed gas in the sealed arc extinguishing cavity can achieve good arc extinguishing ability. The main principle is: after the arc is heated, a high-pressure gas is formed with the filled gas. The increase of gas pressure makes the heat dissociation drop greatly. The pressure difference between the arc gap and the arc extinguishing chamber accelerates the gas movement, intensifies the cooling effect, and quickly extinguishes the arc.
Raw Materials for high-voltage contactors
The development and design of high-voltage contactor must rely on proper raw material selection, advanced process measures, stable parts and tooling, and perfect manufacturing process. Below are raw material requirements of key components for high-voltage contact:
Arc extinguishing chamber: High temperature resistance, high electrical strength, high mechanical strength, good insulation performance, stable chemical performance and corrosion resistance.
Contact: High purity, high conductivity, corrosion resistance, good welding performance.
Arc extinguishing medium: Stable performance and good arc extinguishing ability
Magnetic blown permanent magnets: have stable performance, not easy to oxidize, good dielectric properties, and high permeability
Welding backing of arc extinguishing chamber: small expansion coefficient, good welding performance
Epoxy sealing material: High voltage resistance, impact resistance, aging resistance, high shear and high peel strength, high and low temperature resistance, low shrinkage, low linear expansion coefficient, high bonding strength
Manufacturing equipment for high-voltage contactor
Manufacturing process as a sufficient condition to ensure reliable quality and stable performance must rely on certain hardware facilities.
Laser welding machine, air-tightness detection device, vacuum and gas filling device
Laser Welding Equipment
The laser welding process is a key guarantee process for product quality and reliability. The main purpose of welding is to ensure a good sealing effect, protect the coil and contacts from oxidation and pollution, and ensure the stability of their contact resistance.
The laser welding technology is used to seal the arc extinguishing chamber, so that the arc extinguishing cover, the yoke and the sealing sleeve can be welded without leakage.
The air tightness test of the arc extinguishing chamber after welding is carried out to ensure that there is no air leakage in actual use. Extract and inflate the welded contact system and the complete machine after filling. After evacuating the inside of the workpiece, it is inflated according to the gas type and pressure specified in the process, and the inflating port is automatically sealed.
Glue filling machine, vacuum workbench, glue baking device
Helium Mass Spectrometry Leak Detector
Automatic Glue Filling Machine
The potting process is one of the key processes for epoxy sealant contactors. After potting, the degree of bonding between the glue and the product body and the compactness of the colloid are key points that need to be guaranteed.
In the glue filling process, the air inside the product, the bubbles inside the colloid, and the bubbles generated during the filling process will affect the penetration effect of the glue and the density of the colloid, which in turn affects the sealing performance of the contactor. Utilize the vacuum glue filling system to exhaust all the air in the glue tank and keep it in a certain vacuum state. Before the glue is poured, the air inside the product is cleaned to reach a certain negative pressure, and then the product is poured. Under the force of the negative pressure, the glue can quickly and evenly penetrate into the product.
The air bubbles generated by the product contact will also be sucked away, thus ensuring the uniform coverage of the glue on the product contact surface and the uniform density of the colloid, achieving a good glue filling effect.
After the glue filling is completed, the product needs to be put into a drying oven for curing, and a constant and uniform temperature field, reasonable curing time and heating and cooling rate should be maintained when the glue is baked. Make the curing internal stress and temperature internal stress reach the minimum, ensure good curing effect and bonding effect, so as to achieve a good sealing effect.
Automatic Baking System
DC power supply, resistance load, intelligent control and protection device
The reliable electrical life of the contactor is a very critical performance index. The load failure test is the last guarantee checkpoint before the product leaves the factory.
Aging Test Equipment
Temperature Rise Test System
Electrical Life Test Equipment
Thermal Shock Test Equipment
Gas-filled and Regular DC Contactors
Multiple designing rules have been implemented and verified for satisfying the major DC contractor specifications. Two major designs have been introduced in order to control the electric arc that ensues during the switching phenomenon. One design strategy comprises of gas-filled chambers. Hermetically sealed chambers filled in with shielding gas are integrated into this type of contactor. The most common gasses used are hydrogen and nitrogen. It serves three basic functions: helps cooling the arc; compression of arc by gas pressure and protecting the metal from corrosion which is in contact. The protection from corrosion has removed the compulsion of using silver as a metal, therefore, pure copper is the best alternative for contacts.
In the other type of design strategy, the distance between the contacts is kept larger in order to consistently extinguish the switching arc. Its contact chambers are usually not hermetically sealed. It is important to ensure that a dependable switching function has been integrated at probable altitudes because the atmospheric pressure in the chambers is the same as that of ambient air. Another property that is common in both regular contact and gas-filled contact is the blowing magnets. The process works such that the plasma arc is deflected by the magnetic field in a way that the arc’s length is enlarged, and the diameter is reduced. This helps in fast extinguishing of the arc.
Regular DC Contactor
Gas-filled DC Contactor
While deciding the type of contactor to choose according to your requirement, it is important for you to know their advantages and disadvantages to better suit your necessity. Comparing both the chambers, gas-filled contacts have proven to be more reliable for industrial applications. The contactors are mainly used in the automotive and energy sectors. For the emerging automotive practical applications, it is important to consider the resulting cost. The car manufacturers are more concerned about the reduction in the cost considering alternative drive systems. But generally, EV/car manufacturers prefer to use hermetically sealed contactors, because of the arc, and sparks of regular contactors is not safe for commercial car, passenger car, and regular contactor is noisy. Only low voltage EV like golf-kart, logistic car may choose regular contactor for lower cost.
Digging deeper into the mechanism of the contactors, you will find the different types of sealing used during the manufacturing process and have to decide which one better fits your needs. The detailed guide can be found below.
Epoxy sealed and Ceramic sealed Contact Chambers in a Contactor
Manufacturing the contactors, the sealing of the contact chambers can be done using two basic methods. One is called epoxy sealing and the other is known and ceramic sealing. Epoxy sealing is the usage of glue cast as an adhesive for sticking. While ceramic sealing is the process of heating at high temperature for permanently hardening. In the case of contactors, an epoxy filling: the contacts and components of magnetic circuits are first adjusted in the cup, and the whole cup is then fitted into the housing, crevices are filled with epoxy and baked at the end to seal. On the other hand, during ceramic sealing, the main contacts and the ceramic part is welded at high temperature, then the frame and the ceramic part is welded. The magnetic conductive plate with frame and magnetic conductive plate with an iron core-sheath are laser welded at the end.
Epoxy sealed DC Contactor
Ceramic sealed DC Contactor
As the gas-filled chambers have been discussed above, the choice of gas most suitable for the contact chamber also depends on the type of sealing off the contactors based on two requirements. The first requirement is that the gas is suitably active, the more gas is active, the more likely it is going to collide with electrons that the electric arc releases, which produces the blocking effect resulting in the reduction of heat. The other requirement is that the electrons should not be easily escapable requiring the molecular structure of the gas should be stable. Hydrogen gas fulfills both the requirements as the gas is active and the molecular structure is stable as well. But hydrogen is most suitable for ceramic sealing chambers, as the molecular weight of hydrogen is smaller making it sensitive for leakage, so it requires proper sealing. Nitrogen gas is best suited for epoxy sealed chambers as epoxy cannot seal hydrogen well.
As discussed above, the different methods of arc extinguishing in contactors provide multiple options for our customers to choose between the service life, price and size of the contactors from our ZJQ, EVQ and EVH series.
Hardware Components of Electronics: Main Contactor and Pre-charged Contactor
If you require an EV contactor for vehicle or industrial application, you would want it to work correctly and safely for a longer period. There are many applications of electronics in control systems, talking about hardware designing the basic components in both high and low voltages systems are the same. In most of the hardware, two contactors are the part of the high-voltage front end assembly of components: main contractor and pre-charged contactor. During the implantation of the contactor, the pre-charge contactor is used in combination with the main contractor. The dc switching contactors are used as a switch which opens to stop the flow of current or voltage and closes to start the flow. The purpose of the pre-charge contactor is to avoid a large flow of current at once and allows a small amount to flow into the circuit. When the main contactors shut the switch to complete the circuit, this whole scenario takes place without damaging/disturbing another circuitry. In most systems, there is only one main and one pre-charge contactor. But in the case of some very large systems design, there are numerous interconnected series of strings in parallel combination which may have their own set of contractors permitting them to run independently.
High Voltage DC contactor/Relay can be found in a range of applications, including consumer and industrial transport systems, uninterruptible power systems (UPS), solar energy systems such as photovoltaic (PV) and energy storage systems (ESS). The direct current contactors and alternating current contactor are available on our website with multiple options of voltages ranging from 12v dc contactor, 24v dc contactor to 1000v dc, and current ranging from 50 A to 1000 A.
Future of High-Voltage Contactors:
The latest developments in the high-voltage sector for electric and hybrid vehicles reflect the future demand of the contactors. As the lithium ion-based batteries are expected to have lower internal resistance in the future, this increases the risk of short-circuit currents accordingly. The contactors which are designed such that the contact system is dimensioned according to the predicted short-circuited currents will be able to provide proper functionality. For the increased stability of the product, in the future, it is important that there should be enhanced cooperation between manufacturers of the contactors and battery systems in order to have a balance with the overall system and between the components.