diff options
Diffstat (limited to 'methodology.tex')
| -rw-r--r-- | methodology.tex | 74 |
1 files changed, 65 insertions, 9 deletions
diff --git a/methodology.tex b/methodology.tex index a55ff00..3dd9479 100644 --- a/methodology.tex +++ b/methodology.tex @@ -7,6 +7,29 @@ \section{General Aircraft System} \section{Configuration One} +\begin{table}[!h] + \centering + \begin{tabular}{|c c c|} + \hline + Component& Specification& Serial Number\\ + \hline + Generator&50-kW, 27-kV,120-V Max&15412015470\\ + Rectifier 3$\times$& 500-A, 1600-V&MDS400A1600V\\ + Main Battery 2$\times$&LiPo, 17000-mAh, 14S, 15C, 880.6-Wh&MA-17000-14s-Lipo-Pack\\ + Engine Battery&24-V Lead Acid&\\ + Contactor 2$\times$&500-A, 900-VDC, 24-VDC Coil&LEV200A5ANA\\ + Pre-Charge Resistor& 100-$\Omega$&\\ + Crowbar Resistor&10-$\Omega$ 1500-W Continuous&279-TE1500B10RJ\\ + Main Wire&6AWG Silicone Jacket Wire, 200$^\circ$C, tinned&SW6A3200008F25C2\\ + Battery/ESC Connector&500-A Max, 200$^\circ$C&QS10-S\\ + Phase Connectors&10-mm Bullet Connectors&B00CDAPJ74\\ + ESC 2$\times$&Flier 120-V, 500A&F-500S-A\\ + Wing Mounted Motor 2$\times$&50-kW, 36-kV, 120-V Max&15412015470\\ + Wing Mounted Propeller 2$\times$&2 Blade CF, 0.7-kg, 50$\times$12-in, 77-lbf&\\ + \hline + \end{tabular} + \caption{\label{tab:1components}Configuration One Power System Components} +\end{table} \subsection{Data Acquisition} The turboprop engine control unit (ECU) connects to a laptop-based program. This program outputs @@ -15,21 +38,38 @@ Unfortunately, the controller area network bus protocol used by the engine is proprietary and the manufacturer did not provide software to record data directly. Thus, all engine data was recorded from video capture of real-time graphical read-out, and figures were -created during postprocessing. +created during postprocessing. \textbf{Include PBS CAN Table!!!!} The main data acquisition system consists of three Arduino Megas. Two of the microcontrollers were utilized to record most of the sensor inputs. The third Arduino only measures voltage and was -located inside the aircraft with the pilot. The two main boards utilize -the printed circuit boards detailed in Fig. 9. The board was designed +located inside the aircraft with the pilot. The two main boards interface +with printed circuit boards serve to isolate the controllers from the high voltage +of the system and filter noise. The board was designed to accommodate the numerous sensors present on the aircraft, though this paper will focus on the power data because most of the recorded data was thermistor data and not particularly interesting. All the specifics of the relevant DAQ components are listed in -Table 2. +Table \ref{tab:1acquisition}. +\begin{table}[!h] + \centering + \begin{tabular}{|c c c|} + \hline + Component& Specification& Serial Number\\ + \hline + DAQ 3$\times$&Arduino Mega&A000067\\ + Current Sensor& 500-A, 2\%&LEM DHAB S-124\\ + Current Sensor 2$\times$&750-A, 2\%&LEM DHAB S-133\\ + Voltage Sensor&Arduino Mega ADC, 10-bit&A000067\\ + ESC Controller&Variable PWM Output&B09TW3CY87\\ + Microphone 3$\times$& Dual Omnidirectional Microphones&DR-05V2\\ + \hline + \end{tabular} + \caption{\label{tab:1acquisition}Configuration One Data Acquisition Components} +\end{table} The locations of the hall effect current sensors can be seen in the -main electrical system diagram shown in Fig. 5. The aircraft testbed +main electrical system diagram shown in \textbf{REDO Diagram!!!}. The aircraft testbed consists of 2 LEM DHAB S-133 current sensors that can read up to -750-A and are accurate to within 2% of the actual value. They are +750-A and are accurate to within 2\% of the actual value. They are located after the generator and before the crowbar circuit. A third DHAB S-124 current sensor was also used before the battery, and it can read up to 500-A accurately. This sensor is slightly more @@ -46,12 +86,28 @@ This scaled range was then read by the analog port on an Arduino. For the voltage sensor, a separate dedicated Arduino was used to allow for an increased response rate and ease of electrical isolation. \subsection{Experimental Procedure} +\begin{table}[!h] + \centering + \begin{tabular}{|c c|} + \hline + ESC Throttle& Turboprop Throttle\\ + \hline + Off& Step 0\\ + Low& Step 1\\ + Medium& Step 2\\ + High& Step 3\\ + Medium& Step 4\\ + Low& Step 5\\ + \hline + \end{tabular} + \caption{\label{tab:1testmatrix}Configuration One Test Matrix} +\end{table} Before hybrid-power testing commenced, the system went through a series of preliminary tests to reduce the technical risk of a full hybrid-power system test. These tests were important for informing the test matrix design. First, the turboprop engine was tested to ensure the engine was operating -nominally, before adding the generator [18]. Next, a check run was +nominally, before adding the generator \cite{melvincessna}. Next, a check run was performed using only the batteries, ensuring the power system and electric motors worked properly. The test confirmed that the data acquisition system and electric motors worked correctly. Before full @@ -86,7 +142,7 @@ generator spins freely. This amounts to an all-electric configuration in practice if the generator is outputting below the battery voltage. The output voltage of the generator is around 111.1-V at the maximum power turbine shaft speed. The minimum battery voltage -that was deemed safe is around 20% of the useful capacity. +that was deemed safe is around 20\% of the useful capacity. This meant that the cell voltage of the batteries was brought down to 3.81-V per cell. This brought the 28S battery to a total of 106.7-V, which meant that the generator would only be operating slightly @@ -108,7 +164,7 @@ which lead to a maximum difference of 4.3-V, which is well below 7-V. In practice, because the maximum RPM is not normally achieved under normal operation and there is a voltage drop across the rectifier the full 111.1-V, generator output will not be achieved. -The test matrix in Table 3 was designed to operate at the full +The test matrix in Table \ref{tab:1testmatrix} was designed to operate at the full turboprop throttle position. The test procedure was developed to capture steady and transient data. The engine would be brought up to idle and then brought to full throttle. The low ESC throttle value was |