# Electrical Circuits Simulator in Null-Flux Electrodynamic Suspension Analysis
## 2 Unveiling the Inner Workings: Exploring the Principles and Model of an EDS System
### The Electromagnetic Forces
The dissipative term, which represents the magnetic drag of the system over a period, can be observed in Figure 9. It always decelerates the train, directly proportional to the electric currents in both coils, and inversely proportional to the train's speed. As a characteristic of EDS systems, the drag force reaches its maximum value at low speeds and tends to have a constant value at high speeds [32; 46]. Examining the central part of the last curve in Figure 8 reveals that the guidance force, depicted in Figure 10, had a higher value, which tended to decrease. It is important to note that only one side of the system was plotted. A null-flux coil on the opposite side of the track, with the same 0.185-meter gap, would generate an equal guidance force in the opposite direction, preventing the vehicle from moving sideways. Figure 10: Guidance force for five different speeds. Figure 9: Drag force for five different speeds. The SC coils, designed in a racetrack format, are intended to withstand the electromagnetic forces generated in the EDS system. The lift force acts on the straight horizontal lines of the SC coils, while the propulsion and drag forces act on the curved sides [36]. We examined the effect of varying another circuit parameter, that being the distance between the onboard and offboard coils. The lateral air gap, typically characterized by a value of 0.185 m, was adjusted within the range of 0.170 m (approximation) to 0.200 m (greater distance between the coils). The speed was kept constant at 600 km/h. Figure 12 illustrates the impact on the induced current in the 8-shaped coils resulting from this variation. It can be observed that as the distance between the coils decreased, the induced current increased, when at the same speed. Figure 13 depicts the effect of this variation on the drag force, revealing a signifcant increase. Similarly, Figure 14 demonstrates the direct influence on the levitation force. However, in a railway bogie, one side pulls away from the guideway while the other approaches. The average magnitude of the drag and levitation forces, with only the lateral displacement varying, closely resembles the value of these forces when the Maglev moves without lateral displacement in a non-cross-connected system. Nevertheless, as these forces are vectorial and are applied at different points on the railway bogie, a rotational effect occurs on the train. Figure 7:0 Lift force for five different speeds. Figure 7:1 The electric current induced in one 8-shaped coil fed by one SC coil for six different air gaps. Figure 7:2 Drag force in one 8-shaped coil fed by one SC coil for six different air gaps. Figure 15 provides valuable insights into the influence of varying the lateral air gap on the guiding force, highlighting its high significance. The closer the coils, the greater the guidance force trying to push them apart. In the EDS system, where the ground coil is distributed on both sides of the U-shaped track, the total guidance force is determined by the difference in the guidance force generated by the 8-shaped coil on each side of the bogie. When one side of the bogie is positioned close to the guideway, the other is at an equivalently greater distance.