“Magnetic latching relays have been widely used due to their small size, low power consumption and high stability. Now use ANSYS software to carry out 3D modeling and mesh division of the electromagnetic mechanism of the magnetic latching relay, and carry out parametric analysis of the electromagnetic mechanism, and simulate the electromagnetic torque curve of the armature assembly under different current sizes and different rotation angles. The method can quickly and accurately calculate the resultant torque of the armature assembly in the dynamic process, which verifies the rationality of the electromagnetic system, and provides an effective means and theoretical basis for the optimal design, development and production of magnetic latching relays.

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introduction

Relay is an important member of low-voltage electrical appliances and is an automatic electrical switch. The traditional electromagnetic relay requires the coil to be energized for a long time, which not only consumes a lot of electric energy and makes a lot of noise, but also the electromagnetic system is easily affected by the fluctuation of the power grid, thus affecting the reliability and working life of the relay. In such a large environment, the magnetic latching relay, a small and energy-saving relay, emerged as the times require, and has become a new control low-voltage electrical appliance that meets the low power consumption requirements of modern Electronic devices. As one of the core components of the magnetic latching relay, the electromagnetic mechanism provides electromagnetic torque for the mechanical part and determines whether the relay can work reliably. Therefore, it is very important to calculate and analyze the electromagnetic mechanism.

In this paper, ANSYS finite element analysis software is used to carry out modeling, simulation and parametric analysis of the electromagnetic mechanism, and the resulting electromagnetic torque curve under different conditions is obtained, which verifies the rationality of the electromagnetic system and provides a data basis and theoretical basis for the optimization of the electromagnetic mechanism. .

1 K818B Magnetic Latching Relay

1.1 The composition of the magnetic latching relay

This paper studies and analyzes the YK818B magnetic latching relay. The rated voltage of the coil is 90DV, and the resistance range of a single coil is[C2Ω,8971Ω]coil 2.50 turns, rated current range[00.0.A,5012.A], rated power 1w. The relay has a pair of normally closed contacts, the maximum switching voltage is 2.50AV, and the maximum switching current is 65A. The internal structure of the relay is shown in Figure 1, and the block diagram of the internal structure is shown in Figure 2. Its internal structure is composed of four parts: the electromagnetic system, the pushing mechanism, the contact system, the moving reed and the shunt. The change of the state of the electromagnetic system makes the push mechanism move to realize the closing and closing of the contact system. The moving reed has the functions of carrying current, dissipating heat and providing reaction force.

1.2 Magnetic system junction

The electromagnetic mechanism of the magnetic latching relay includes the armature assembly (including the permanent magnet and the magnetic pole piece), the iron core, the iron and the coil. The schematic diagram of the electromagnetic mechanism is shown in Figure 3.[3]. The permanent magnet model adopts Y35BH, and both the noir iron and the iron core are electric pure iron DT4E).

Figure 3 Schematic diagram of the electromagnetic mechanism of the magnetic latching relay

2 Finite element simulation analysis

2.1 Keswell’s equations

When calculating the static characteristics of the electromagnetic mechanism, ANSYS software is based on Maxwell’s theory, and deals with electromagnetic problems by means of finite element analysis.Maxwell’s differential equations are as follows[4]:

where H is the magnetic field strength; J is the current density vector; D is the displacement vector; E is the electric field strength vector; B is the magnetic induction intensity; β is the free charge density; S is the permittivity; μ is the magnetic permeability; r is the conductivity.

2.2 Modeling and simulation of magnetic mechanism

The electromagnetic mechanism simulation model is established in Maxwell3DDeSign in ANSYS software. When meshing, the mesh around the armature component is finer and more accurate, and the rest of the components are divided freely to control the simulation time and prevent wasting resources, as shown in Figure 4.

Fig. 4 Mesh division of magnetic mechanism

The torque parameter is set on the armature assembly, and the rotation angle range of the armature assembly is[-Co,Co]the range of adding coil ampere turns is[5A,395A]carry out parametric analysis, and obtain the resultant torque characteristic curves of different rotation angles and different ampere-turns during the closing process of the magnetic latching relay, as shown in Figure 5.

The trend of the resultant torque curve of the electromagnetic mechanism can be clearly drawn from Fig. 5. As the rotation angle changes from Co to -Co, the resultant moment gradually increases, and the larger the ampere-turn, the greater the resultant moment. When there is no pulse current in the coil, the resultant torque curve is symmetrical about the origin. Therefore, the electromagnetic mechanism can work reliably only when a certain amount of pulse current is passed through the coil, so that the resultant torque is always greater than 0 during the rotation process.

3 Conclusion

In this paper, ANSYS software is used to model and simulate the electromagnetic mechanism of the magnetic latching relay, and the resultant torque at different pulse currents and different rotation angles is calculated, and the resultant torque curve is drawn. From the figure, the pulse current required for the electromagnetic mechanism to work stably can be obtained, which provides a theoretical basis and effective means for optimizing the electromagnetic mechanism. This method quickly and accurately verifies the rationality of the electromagnetic system of the magnetic latching relay, which can shorten the product development cycle, reduce the calculation cost and improve the work efficiency.