A Class-E Amplifier for a Loosely Coupled Inductive Power Transfer System with Multiple Receivers

Abstract

We present a method for optimizing the electronic power system for a new type of photobioreactor or photoreactor in general. In the case of photobioreactors, photosynthetic active microorganisms or cells are grown. A novel concept for the illumination of photobioreactors was necessary, as the external illumination of those reactors leads to a limited penetration depth of light. Due to the limited penetration depth, no standard reactors can be use for cultivation, but custom made reactors with very small volume to surface ratio have to be used. This still prevents the technology from a large scale industrial impact. The solution we propose in this paper is an internal illumination via Wireless Light Emitters. This increases the manageable culture volume of photosynthetic active microorganisms or cells. The illumination system is based on floating light emitters, which are powered wirelessly by near field resonant inductive coupling. The floating light emitters are able to illuminate a photobioreactor more homogeneously than external illumination systems do. We designed a class-E amplifier and field coils to produce an intermediate frequency electromagnetic field inside the reactor. An appropriate magnetic flux density was found to be approx. B = 1 mT and the driving frequency is f = 176 kHz. We conducted experiments with a laboratory size photoreactor. The cultivation volume was 30 L containing up to 3000 WLEs. The maximum electric power input was more than 300 W and we calculated an efficiency of up to 76%.

Intensification of Photobiocatalytic Decarboxylation of Fatty Acids for the Production of Biodiesel

“…At perfect quantum efficiency and assuming loss‐free photon generation, the maximum theoretical energy efficiency of the reaction [Δ c H 0 products ×(Δ c H 0 educts + E photons ) −1 ] would be as high as 98.1 %. Even though the actually achieved energy efficiency in this non‐optimized lab setup was 32.1 %, already 89.8 % appear possible with the AQY reached here by optimizing the setup to match state‐of‐the‐art efficiencies for the electronic parts and the inductively coupled energy transfer [26] as well as the LEDs (see the Supporting Information) [27,28] . This is remarkable considering that established processes for the synthesis of renewable fuels such as Power‐to‐Liquids reach energy efficiencies around or below 50 % [29] …”

Inductive Tracking Methodology for Wireless Sensors in Photoreactors

“…For the wireless illumination, this problem was solved in setting the center of gravity of the WLE in a low position inside of it. In doing so, the WLEs align themselves while floating around in the photoreactor [ 5 ]. The same approach can be used for the wireless sensors.…”

“…The generated magnetic flux density is approx. at a frequency of [ 1 , 4 , 5 ]. The internal illumination system based on the WLEs is also used to perform photocatalytic reactions; therefore, the WLEs are coated by a photocatalyst [ 6 ].…”

Inductively Powered Sensornode Transmitter Based on the Interconnection of a Colpitts and a Parallel Resonant LC Oscillator

“…The long-term aim of this research is to expand the internal illumination system presented in [9][10][11] with locatable wireless sensors, in order to allow a better insight into the processes inside the reactor. The sensornode therefore needs a wireless power receiving unit that takes the energy provided by an inductive power supply in order to supply the whole transmitter.…”

“…In this paper, we therefore present a design for realizing the transmitter electronics for a battery-free wireless sensornode that uses wireless inductive power transmission as an energy supply and the inductive data transmission for sending the measured data. Our system is conceived for use in the internally illuminated photoreactors presented in [9][10][11]. Those photoreactors already use inductive wireless power transmission for powering their internal illumination.…”