Complex Electromagnetic Issues Associated with the Use of Electric Vehicles in Urban Transportation

Abstract

The electromagnetic field (EMF) in electric vehicles (EVs) affects not only drivers, but also passengers (using EVs daily) and electronic devices inside. This article summarizes the measurement methods applicable in studies of complex EMF in EVs focused on the evaluation of characteristics of such exposure to EVs users and drivers, together with the results of investigations into the static magnetic field (SMF), the extremely low-frequency magnetic field (ELF) and radiofrequency (RF) EMF related to the use of the EVs in urban transportation. The investigated EMF components comply separately with limits provided by international labor law and guidelines regarding the evaluation of human short-term exposure; however other issues need attention-electromagnetic immunity of electronic devices and long-term human exposure. The strongest EMF was found in the vicinity of direct current (DC) charging installations-SMF up to 0.2 mT and ELF magnetic field up to 100 µT-and inside the EVs-up to 30 µT close to its internal electrical equipment. Exposure to RF EMF inside the EVs (up to a few V/m) was found and recognized to be emitted from outdoor radiocommunications systems, together with emissions from sources used inside vehicles, such as passenger mobile communication handsets and antennas of Wi-Fi routers.

Keywords: electric vehicle; electromagnetic compatibility; electromagnetic exposure; electromagnetic field; environmental engineering; exposure; urban transportation.

Figure 1

Charging of PEVs with the use of: (a) slow AC charger and cable connected to the socket in the passenger car (AC/DC rectifier inside car); (b) fast DC charger station (AC/DC rectifier outside car) and pantograph system (source: the authors’ collection).

Figure 2

The magnetic field waveform recorded in the vicinity of installations supplying driving engines inside a plug-in electric vehicle (PEV) type of bus; illustrative non-calibrated recordings using magnetic field flux density (B) probe of 1–400 kHz flat frequency response (source: the authors’ collection).

Figure 3

The frequency spectrum of sinus waveform (a,b) and single rectangular pulse (c,d) (illustration on the base of Fourier transform principles).

Figure 4

Examples of RF EMF frequency spectrum in the range (80–3000) MHz recorded in the center of a big city (source: the authors’ collection).

Figure 5

Variability of electric field strength (E) in the frequency band 88–2170 MHz, recorded in the driver’s cabin of a PEV bus with indoor Wi-Fi 2G router located on the ceiling while the journey with passengers over the city downtown (black line—total broadband exposure; grey line—narrow-band component from the internal Wi-Fi 2G equipment), (source: the authors’ collection).

Figure 6

Statistical parameters of narrow-band frequency components of electric field strength (E) recorded in the passenger section of PEV buses equipped in indoor Wi-Fi 2G routers or without Wi-Fi routers during journeys with passengers through the city downtown; GSM (U) and GSM (D)—GSM 900 uplink and downlink, respectively; DCS (U) and DCS (D)—DCS 1800 uplink and downlink, respectively; UMTS (U) and UMTS (D)—UMTS 2100 uplink and downlink, respectively (source: the authors’ collection).