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Products Tracking Accuracy

BPI Tracking Accuracy Sensor

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Products v04 02

Technical Data

TA1 web01

Fig 1:TA Sensor with +/- 1.2° measurement range

  • Measurement range +/- 1.2 °, other ranges on request
  • Build-in low-noise pre-amplification and signal conditioning allows for measurement rates of 1 kHz and more for vibration analysis.
  • Highest linearity and accuracy
  • Sensor output: 4 analog voltage outputs -10 ... + 10 V
  • Mounting: Adjustable with 3-point spring mounting
  • Outdoor-proof encapsulation
  • All-metal housing for excellent EMC shielding
  • Industrial-grade M12-connector for easy hook-up

   Download file Download Specification

Applications

  • Lower the LCOE by optimizing the tracker control strategy: The high measurement frequency of up to 1 kHz provide great insights into the performance of a tracker control strategy in real time (see also examples below). This insight can be used to optimize the control parameters like cycle time, threshold value or drive current ramps. Maximize the output of your PV system without any additional tracker production or materials costs!
  • Determine the position of the tracker during important measurements: For high concentration solar systems, it is important that the tracker is in the correct position during important measurements, such as IV-curve or acceptance angle measurements. With the TA sensor, you can exactly see how well the tracker is aligned during each step of the measurement.
  • See how a tracker behaves under static and dynamic loads like weight of modules or different wind speeds. Due to the high resolution and measurement frequency, the damping properties for dynamic loads can be determined.
  • Measure the bending of the tracker structure using two or three sensors simultaneously at different places on the tracker structure. The achieved results allow for a structural optimization of the tracker.
  • The sensor can be used to perform several measurements as proposed in the draft version of the IEC WG7 TC 82 tracker design qualification standard. Contact us if you need information on how to get started with measurements or involved in the standard development process. 

Measurement Examples

Details_azimuth

Figure 2: Azimuth signal measured on a high concentration CPV tracker with the TA tracking accuracy sensor from BPI. Sampling frequency 10 Hz 

Figure 2 shows a typical measurement result with the Black Photon tracking accuracy (TA) sensor mounted on a tracker suitable for high concentration photovoltaics. The tracker used in the example has a control loop of 20 s for the azimuth drive. During this time, the engines of the tracker are off to save energy and minimize drive wear. During this period, the sun slowly moves away from the tracker plane (exhibit "A" in Figure 2). At the end of a control cycle, the tracker azimuth drive is activated and quickly moves the tracker in the other direction (exhibit "B" in Figure 2). The drives are only activated if a certain threshold is reached, therefore tracking cycle intervals can also reach multiples of the 20s duty cycle. After the drives come to a stop, a small vibration of the tracker structure can be noticed, which is however well damped and does not affect the accuracy of this tracker.

As can be seen in this analysis, valuable information of the tracking control strategy, the tracker structure, and in the distribution of the accuracies can be gained by using the high resolution measurement signal of Black Photon's TA sensor.

Detail Elevation VibrationElevation Fourier Analysis

Figure 3: Vibration analysis of a mounting system with low mechanical stiffness and low damping. Left: Signal of the Black Photon Instruments TA sensor (elevation signal only) after mechanical excitation of the tracker. Right: Fourier analysis of this vibration (frequency domain, amplitude).

Figure 3 shows the measurement of the elevation axis of a mounting system with low damping properties. The mounting system has been dislocated with mechanical force and then released. A dominant Frequency around 0.35 Hz can be noticed (Eigenfrequency). This analysis gives valuable information for structural optimization of the mounting system by the mechanical engineer.

Recalibration in the Field

The continuous movement of the earth provides a highly accurate calibration source (much envied by anyone engaged in spectral calibration of solar radiation). This calibration source can be used to recalibrate the BPI-TA sensor in the field, or check the validity and accuracy of measurements at any moment. An excel tool for this purpose is provided with every sensor delivered.  

Data Logging & Processing

The sensor provides analog voltages which can be recorded with a simple data logger or can be integrated into the most complex power station monitoring system.
For a stand-alone advanced logging solution including wireless / GSM access, integration of up to 20 sensors, integrated database-solution and data-preprocessing, we offer our highly reliable monitoring system BPI-SYS.

Technology

HermeticPackage Icon Learn more about the technologies
employed in our sensors. 

   

Last Updated on Wednesday, 30 April 2014 20:57