Autonomous Rail Rapid Transit (ART) Prototype Concept Using Wireless Charging System with Electromagnetic Induction Coupling

The development of charging technology in Autonomous Rapit Rail Transit (ART) vehicles uses a wireless power system by optimizing. The selection of the power transfer method uses an Inductive coupling of the LCCL model with a wide variation in the cross-section of the wire and the diameter of the fixed coil. Scenario testing by installing a power transfer system on ART facilities, testing is carried out on coil

The development of charging technology in Autonomous Rapit Rail Transit (ART) vehicles uses a wireless power system by optimizing. The selection of the power transfer method uses an Inductive coupling of the LCCL model with a wide variation in the cross-section of the wire and the diameter of the fixed coil. Scenario testing by installing a power transfer system on ART facilities, testing is carried out on coil inductance, resonance coupling gap and power efficiency. Optimum power transfer is obtained on coils with a cross-sectional area of 1.5 mm / 6.13 μH and the highest power transfer efficiency of 40% at a distance of 0.5cm. [3] for the quality factor and the resonator connection. Regarding the wireless power transfer performed to increase efficiency by increasing longer distances in this paper optimized shunt-series resonance circuit structure.
Zhang et al [17] in their research consider electromagnetic or radio frequency (RF) WPT specifically. Because the RF signal is able to transmit information and power simultaneously. This paper specifically studies multiple-input multiple-output (MIMO) [18] [19] wireless communication systems consisting of separate nodes, where one receiver harvests power while the other decodes information separately from a common transmitted signal to two receivers. Two different scenarios were also isolated, the first in which the second receiver and MIMO channels were different, and the other saw when they were placed together and saw the MIMO channels from the same transmitter.
From circuit analysis and numerical simulation, the advantages of shunt-series resonance coupling [20] have the advantage of high-efficiency transfer under different distances. A relative distance scaling factor is proposed to evaluate system performance, and optimization is defined as setting the ratio of transfer distance to resonance coil diameter. It was found that the transfer efficiency was close to expectations when it used shunt-series resonance with an optimized capacitor. This is especially useful if the clutch coefficient is very small, allowing for a longer transfer distance or a more receiving coil.

WIRELESS POWER TRANSFER
Wireless power transfer (WPT) is a great strategy for moving electrical energy from one point to another over a vacuum or atmosphere without the use of traditional cables or other materials [21]. WPT system is required to power electrical devices where physical interconnection of wires are impractical, dangerous or poorly arranged. WPT has inherent advantages such as enablement of transmission over long distances; convenient and flexible use; inexistent or low wear rates since use of wires have been greatly reduced [22]. WPT can be achieved using a number of methods including inductive coupling, microwave, and laser [23]. Research on WPT was conducted by Low et al [24], Lee at al [25], Kim et al [26], and Kurs et al [27] Low at al focused on an approach proposed to achieve a very efficient WPT system that accomplishes a low-power loss by using the Class-E mode of operation. This system can accomplish an efficient powerdelivery response over a range of load resistances with no control system or a feedback loop but depends on its natural impedance reaction or response to be able to accomplish its desired power-delivery profile over a wide range of load resistances, while maintaining a high efficiency to prevent any heating issues. Lee et al proposed an equivalent or a corresponding circuit model for the wireless transfer of power of 60W and above and examines the system based on the proposed model. The proposed model was validated using finite-element analysis (FEA) and some experimental results. Also, for high-power applications, there were investigations of the losses in WPT systems. Kim et al Kim et al, focused on the principles of magnetic field resonance WPT techniques while highlighting the effects of EM field noise from WPT and the related shielding methods for different applications. The efficient combination of this concepts helps ensure maximum power transfer. While, Kurs et al argued that there tends to be better efficiency of energy exchange with relatively little dissipated energy when two resonant objects of the same resonant frequency are coupled together.
WPT channels electrical energy from a voltage source to a load without wires. In energy distribution systems, the power delivered is very important so the efficiency of the link (link) needs to be considered [28]. Figure 2.1 shows the WPT system using an electromagnetic resonance coupling. Wireless Power Transfer [12]consists of a driver loop, transmitter coil (Tx), receiver coil (Rx) and load loop (load). Each antenna transmitter (Tx) consists of a loop and coil. When the generator powers the driver loop, the electric force of motion (electromotive force) induces the Tx coil. When the receiver coil (Rx) is excited (exited), the electric motion force induces in the load loop. Interaction occurs because two coils have the same resonance frequency. The displacement current between the two coils due to the difference in potential of each cycle induces a magnetic field, resulting in a magnetic coupling between the two. This means coils of the same frequency can resonate, share [4] electromagnetic fields, and channel energy efficiently. Power induction can be calculated using the following equation [  The resonance condition is that both coils have the same frequency (f). To analyze the frequency that can be generated from an LC circuit, the analogy that the inductive reactance value (XL) is equal to the capacitive reactance (XC) we can make it in the following equation: The LC circuit forms alternating current from the direct current source. The characteristics of the inductor (L) are storing magnetic fields while capacitors (C) store electric fields [30]. The values L and C can affect the magnitude of the signal raised. The principle of filter C is filling and emptying the load. The filling lasts until the maximum value, when the voltage on C is equal to Vp. On the swing down, C will empty the is no load, the value is constant and equal to Vp, but if there is a load, then the output (Vout) ripples due to emptying conditions. The following equation following equation following equation can calculate the required value of C following equation can calculate the required value of C: The principle of electromagnetic induction is that when alternating current passes through a coil, around the coil will form a magnetic field (B). If, in this condition, is placed near the coil, then the first coil's magnetic field will also arise around the second coil. This is why cordless energy delivery can occur between the two coils. The value of L can be calculated using the following equation: can be simplified to: Where, The resonance frequency of the coils is of the same value as the frequency of the alternating current, when the equivalent circuit of the coils is at a high frequency (f) and has the smallest impedance (Z). In these conditions these conditions and the most energy can be transmitted through the resonance.

RESEARCH METHOD
The system block diagram describes the application of the Autonomous Rapid Rail Transport facility, where when the means enter the stop, the inductive proximity sensor detects the means and then ignites the relay to channel the voltage from the 12V power supply to the transmitter circuit. Electrical power flows through the sending circuit to the resonant coil.

Figure 2. Block Diagram of Wireless Charging System
The resonant coil generates electromagnetic energy with a frequency equation with a frequency equation. The coil receives the energy radiated by the sending coil and then re-routed by the bridge diode. The output of the receiving circuit is divided into two regulators. 5Volt output as power supply equipment and 12Volt output pass-through current sensors and voltage sensors to know the magnitude of the current and output voltage of the receiving circuit as electrical power channeled to the load battery. Monitoring parameters using equipment devices.
Equipment is made using a MOSFETs that serves as a coil switch drive. This transmitter circuit works using a zero-voltage switching (ZVS) system. Electrical energy flows to the coil section quickly so that the coil produces electromagnetic which induces and causes Eddy Current. The transmitter circuit generates a magnetic field around the coil forming magnetic field lines. The magnetic field of this sending coil will induce a series of receivers on the condition that it must be in the area of the magnetic field force of the transmitter coil. The magnetic field generates a current in the receiving coil and is converted into a direct current in the receiver circuit using a diode. The current in this receiver circuit is raised using A1941 type transistors so that the output current from the regulator increases and can charge the batter.
The coil used is a solenoid in shape with a predetermined diameter and number of windings. This coil capture produces a magnetic flux in the sender's string. To captures produces a magnetic flux in the sender's string and captures electrical energy in the receiver circuit. Prototype in the form of autonomous rail rapid transit (ART) uses fiber material with dimensions of 38 x 7 x 15cm. The inner prototype is used to put the equipment components used. The monitor is on the roof prototype. Prototype ART has a workflow starting from the means of entering the charging point until the monitor displays voltage and charging current. The ART design can be seen in the following image. Design transmitters use Schematic Diagram software Eagle. Several components include terminal blocks, relays, diodes, resistors, LEDs, MOSFETs, and capacitors. In the manufacture of this PCB using Eagle software. PCB itself functions as a link of electronic components in a computer with its conductor line layer. In this study, the type of PCB used is a single layer. Transmitter series combines several components into a circuit that serves as a sender of electrical energy to the receiver circuit wirelessly. There are components such as terminal blocks, diodes, capacitors, IC regulators, transistors, and USB ports. The receiver circuit is a combination of components that will react to the energy distribution of the transmitter circuit.  Test the receiver by bringing the transmitter coil and receiver coil closer together. In the event of electromagnetic wave resonance, the receiver circuit will receive power and the monitor can show the presence of voltage and flow of charging current to the battery on the receiver circuit.
Transmission gap testing is carried out to get parameter data which will then be used for wireless power system optimization. The test used a series of transmitters connected to a 12 Volt 5 Ampere power supply to generate electromagnetic induction on the transmitter coil. The transmitter coil and receiver coil are placed opposite each other. Next the gap between the coils from 0 cm to 4.5 cm with a step gap every 0.5 cm. Measurements are made to see the changes in energy that the receiver circuit can receive. To see the power that can be delivered, a digital multi meter is installed to measure the current and voltage. The digital multimeter is attached to the transmitter circuit input while the receiver circuit output is displayed on the monitor attached to the prototype. [8]

. Coil Testing
Coils are made using an enamel wire size of 1.0 mm wrapped around the shape of a circle with a circular diameter of 6.5 cm and as many as 15 windings. Make two coils that will be connected to the transmitter and receiver circuits and connected to the load in the form of a lithium-ion battery 18650. The coil is made using a 1.5mm enamel wire wrapped around a circle with a circular diameter of 6.5 cm and as many as 15 windings. Make two coils that will each be connected to a series of transmitters and receivers and connected to the load in the form of a lithium-ion battery 18650.

Performance Wireless Power System
Transmitter performance is indicated by measuring the transmitting voltage, transmitting current, and transmitting power. The ratio of transmitter voltage in the coil whose cross-sectional area is 1.0 mm with the [9] inductance of 7.26 μH and the voltage in the coil whose cross-section area is 1.5 mm with the inductance of 6.13 μH does not appear to change, the voltage is relatively stable, there is no voltage drop due to resonance load. The comparison of the transmitter current in the coil of 1.0 mm / 7.26 μH and the coil of 1.5 mm / 7.13 μH appears to change in current change current change due to the resonance load. The transmitting current in the 1.0 mm coil is first at a gap of 0 Cm large and stable at a gap of 0. 5 -3.5 Cm, but at a gap of 4 to above Cm it appears to drop. While the transmitting current in the 1.5 mm coil is first at a gap of 0 Cm large and stable at a gap of 0.5 -4.5 Cm. Then the transmitting power occurs, the same thing with the transmitting current. The 1.5 mm/7.13 μH coil is more optimal in power transfer resonance, and the gap is further. Receiver performance is indicated by the measurable voltage received, receive current, and receiving power. The ratio of the receiver voltage in the coil whose cross-sectional area is 1.0 mm with the inductance of 7.26 μH and the voltage in the coil whose cross-section area is 1.5 mm with the inductance of 6.13 μH there seems to be a change, at first large but slightly smaller at a gap of 0 Cm and a voltage drop at a gap of 3.5 Cm in the coil of 1.0 mm. As for the 1.5 mm coil, the voltage is slightly greater at a gap of 0 Cm and can still resonate at a gap of 4.5 Cm. Voltage drop is caused by resonance load. The ratio received currently in the coil is 1.0 mm / 7.26 μH and the coil is 1.5 mm / 7.13 μH appears to have a change in current due to resonance load. The received current in the 1.0 mm coil can resonate at a 0 -0.5 Cm gap. While the received current in the 1.5 mm coil can resonate at a gap of 0 -1 Cm. Then with receiving power the same thing happens with the received current. The 1.5 mm/7.13 μH coil on the receiver circuit is also more optimal in power transfer resonance. V Rx 1mm I Rx 1mm P Rx 1mm V Rx 1,5mm I Rx 1,5mm P Rx 1,5mm [10]

Figure 10. Efficiency Graph of Transmitter and Receiver
From the graph above, it can be explained that the use of coils with a wire size of 1.0 mm can get the highest efficiency of 30.72% at a distance of 0 cm (sticking to each other). While the use of coils with a wire size of 1.5 mm can get the highest efficiency of 40% at a distance of 0.5cm.

CONCLUSION
From the results of the wireless power system application research in the Autonomous Rail Rapid Transit (ART) prototype with Electromagnetic Induction, it can be concluded that the design of wireless charging in the Autonomous Rail Rapid Transit (ART) Prototype with electromagnetic induction produced by the transmitter circuit and receiver circuit and using coils of enamel wire measuring 1.0 mm and 1.5 mm wrapped around into a circle with a diameter of 6.5 cm as much as 15 windings. Based on the results of testing the transmitter and receiver circuit on the wireless power system prototype autonomous rail rapid transit (ART), the receiver coil that best receives electrical power is a coil with a wire size of 1.5 mm that can receive a voltage of 13.1 Volts and a current of 1.2 Amperes at a distance of 0 cm. The farthest distance in this test is 4.5 cm with a transmitter voltage of 12.6 Volts, the receiver coil with a size of 1.5 mm can still receive a voltage of 0.3 Volts at that distance. Better power transfer efficiency on 1.5 Cm coils can get the highest efficiency of 40% at a distance of 0.5cm. doi: 10.1007/s40534-016-0117-3.