Electric bus platform for urban mobility

Abstract

Today, the technology of automatic battery charging based on Wireless Power Transfer (WPT) for the electric mass transit industry involving electric trains, buses and trams, is being used more and more. The modern solution described in this paper proposes an innovative technology for mixed charging of electric buses, either by wireless charging for 2-3 minutes in selected stations, or by plug-in charging at the end of the bus line, which results in only minimal energy storage on board - practically enough to get to the next charging station. The reduction of the weight of the battery packs determines the increase of the number of passengers transported, but also a reduction of the purchase price of the bus, without reducing the performances. The conversion can cost about half the price of new electric buses, depending on the condition of the vehicle and the extent of the work. This solution can be applied especially for the conversion of Diesel buses into electric buses which is not only sustainable, but also significantly better in terms of investment and operational costs, comparing with the purchase of new electric buses.

Analysis of Some Geometric Parameters of the Inductive Coupler Intended for High Power Wireless Systems

“…1. Ea este alcătuită din sistemul de bobine D-D [3] transmițătoare (Tx) montate în nișe practicate într-un material magnetic realizat dintr-un beton special cu proprietăți magnetice descris în [4,5]. Sistemul de bobine D-D receptoare Rx identice cu cele transmițătoare Tx (dimensiuni și număr de spire), este amplasat pe un miez de ferită clasic la partea inferioară a VE.…”

Inductive Coupler for Battery Charging System of Heavy Electric Vehicles

“…At this power level, the classic single Tx-Rx coupler (SISO) cannot be used by simply increasing its dimensions due to the large working distance Z, although the existing space of EB is large enough. Thus, it will be replaced with a MIMO system consisting of two transfer systems with coils in the double D topology with a unitary power of 75 kW placed in line in the EB travel direction, from now on referred to as 2x2 MIMO as shown in [4]. Couplers with a 4x4 or even 6x6 MIMO structure made of identical optimized 2x2 modules can be used for higher power classes.…”

“…In the case of urban electric buses (EBs) that have wellestablished routes, there are two approaches regarding the increase of the travel distance: buses with high-capacity batteries to cover the entire daily operating time and nighttime charging in the depot practiced on new buses, respectively buses with batteries with lower capacity wirelessly charged on the route or at line ends [4], a preferred method, especially for diesel buses converted to electric buses and called "opportunity charging".…”

“…This paper follows a cycle of Romanian works dedicated to this subject [4,[6][7][8], which refer exclusively to the wireless charging of batteries from EBs, which is currently safe, compact, and efficient. The technical solutions adopted by the precursors [9,10] for the wireless charging of the necessary batteries represent a basis for the standardization of the solutions in the new draft standard SAE J2954/2 [11] intended for HDEV which includes both buses and trucks that appeared under the form of "Recommended Practice" in 2022.…”

Mimo Inductive Coupling for High Power Wireless Systems

“…În cazul autobuzelor electrice există două abordări privind creșterea distanței de deplasare: baterii cu capacitate mare pentru acoperirea întregii durate de funcționare zilnice și încărcare nocturnă în depou, respectiv baterii cu capacitate mică încărcate wireless pe traseu sau la capete de linie [3], metodă preferată în special pentru autobuzele Diesel convertite în autobuze electrice.…”