Home > Exhibition > Content

Analysis of new energy automobile relay and contactor

Dec 12, 2018

Relay is a kind of control component, is a kind of circuit switch with protective properties, is the core component of new energy vehicles.

Main function

Low voltage remote control the on - off switch of high voltage circuit ( Use safe low voltage 12V~72V control unsafe high voltage 300V~ 1000V )

Main funtion

It is usually used in automatic control circuits, It is actually an "automatic switch" that operates with a small current to control a large current. In the circuit, with other components constitute a safety protection mechanism, It has the function of conversion circuit and so on.

Main feature

With the characteristics of fast action, small size, high arc extinguishing safety, high reliability, long life.

What is the difference between a relay and a contactor?

Some people call “contact” that on alternating current and call “relay” that on direct current at the earliest time, the reason is that the contactor on alternating current is large, the contactor on direct current is small, and some are all called contactors.

There is no difference in function between the relay and the contactor, both of which are control switches. Early contactors were used in alternating current. Since dc circuit design focuses on integrated miniaturization space, and the development of a compact contactor compression version at low dc voltage, for the distinction called relay.

With the development of society, the dc voltage and current are increased, also appeared high voltage relays, contactors are also being miniaturized, it is difficult to distinguish between relays and contactors, and there is no standard distinction between industries and countries. In addition, there are many different versions of relay, such as time relay (automatic disconnection and connection within a certain time), high temperature relay (automatic disconnection and connection when a certain temperature is detected) and so on.

 If relay and contactor are said to be a power switch, what is the difference between them and ordinary switches?

High voltage relay is mainly used in remote control switch of high voltage and high current.

In high voltage and high current, any circuit on - off operation will produce an arc or spark, the higher the voltage, the longer the arc is generated, and the greater the current, the greater the heat generated, the extended arc may hit the operator or controller circuit or burn out the control circuit board at high temperature to make it to be failure.

For our daily household voltage 220V current is only about 10A, just use the ordinary switch.

However, the special switch applied in the high-power and high-current industry is too complicated and huge, and consumption for the control energy is huge, which is only suitable for specific projects

In this way, the remote control switch relay which meets the requirements of miniaturization, high current, low consumption and safe arc extinguishing is widely used in the new energy industry.

Why do relays have positive and negative poles?

Not all relay contacts are divided into positive and negative poles, only for magnetic blow-out arc relay, and magnetic field gravity has a certain direction.

On the contrary, the negative pole introduces current, and the current magnetic field and the core magnetic field repel each other, Push the arc close to the contact to form a stable arc that is difficult to disconnect.

For the small current relay, the arc power is small and easy to be cut off, so the magnetic core is not used, so there's no distinction between positive and negative, and the volume can be made smaller, no polarity also can be achieved by using other arc extinguishing mechanisms, but if the volume is relatively large it will consume too much energy, but the relay are designed to be lightweight and low in consumption.

The difference between dc relay and ac relay?

For the low-voltage relay, control current is used to distinguish it directly, and dc control on and off is called dc relay, ac control is called ac relay, contacts can be connected to dc or ac.

For high voltage relays, not only use the control current to distinguish it, but also use contact to distinguish it, When the contact is direct current, Dc is divided into positive and negative poles, the arc generated stable direction, the magnetic blowing process is used to quickly extinguish the arc, the contact which use the magnetic blow-out technology is DC contactor. When contact alternating current, AC is non-polar, generate the arc and the direction are weak and self-extinguishing and unstable. Adopts the technology of arc leakage prevention is AC ralay.

The relationship between the main contact and the auxiliary contact

Auxiliary contact is used to detect the current state of the main contact, check whether the main contact is disconnected uniformly as the control instruction, and determine whether the main contact is invalid.

What can relays and contactors do?

1. The relay can switch on and off the circuit remotely in the circuit to realize the function of remote switch.

 2. Switching current circuit with on off to achieve multi-circuit intercutting function,

3. Multi - device Shared circuit is realized by multi - line switching function, So as to achieve device miniaturization.

4. With other components to form an automatic control circuit

5. With other components constitute real-time detection monitoring security mechanism

6. Cooperate with the system to prevent electric shock, fire, equipment damage and other automatic cut off protection

7. Automatic industrialization

8. Relay is the core component of control circuit and the core component of new energy vehicle.

Application and range of high voltage DC relay

1.Mainly for the new energy industry in the automotive, solar, wind energy, charging pile, power storage system, Industrial automation, power protection, automation, movement, remote control, measurement and communication.

2. Switch and protect battery charging and discharging lines in new energy vehicles, constitute safety mechanism to prevent equipment failure or short circuit, fire, etc.

3. Cooperate with the system in charging pile to automatically record charges, transmit electricity and disconnect, and automatically detect and protect the charging pile from over charging, electric shock, leakage and other improper operations.

4. In solar power generation, it is applied in the real-time detection system to assist the solar panel detection system to isolate the aging, damaged and short-circuit panels, In order to reduce the impact of efficiency, the system remote control panel maintenance, anti-shock, leakage, save maintenance costs, and prevent the expansion of damage range, so as to improve the life of the power board.

5. In the power storage system, circuit switching is realized, and a leakage detection system is constructed to prevent the impact of surge on battery life, prevent over-charging, over-discharge and other protection.