Abstract:
An apparatus and a method for testing and/or conditioning photovoltaic modules. The apparatus includes a set of contacts for contacting electrical conductors of the module and a testing and/or conditioning system for testing and/or conditioning of the module and measuring parameters associated therewith.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to U.S. Provisional Application No. 61/539,314, filed Sep. 26, 2011, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the invention relate to the field of photovoltaic power generation systems, and more particularly to methods and systems used to test and/or condition photovoltaic modules during manufacture. 
     BACKGROUND OF THE INVENTION 
     Photovoltaic (PV) modules convert solar radiation to electrical current using the photovoltaic effect. During manufacturing of the modules, minor variations in process parameters may result in modules having dissimilar performance characteristics. Dissimilar performance characteristics are undesirable because the design and performance of a photovoltaic array may rely on each module performing according to product specifications. Therefore, it is desirable to manufacture modules that exhibit similar performance characteristics when installed in the field. Moreover, it is desirable to manufacture modules that maintain similar performance characteristics over the life expectancies of the modules. An efficient way to test and/or condition manufactured modules is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a PV module according to an exemplary embodiment. 
         FIG. 2  is a perspective view of a partially assembled PV module according to an exemplary embodiment. 
         FIG. 3 a    is a diagram of a PV module testing and conditioning system according to an exemplary embodiment. 
         FIG. 3 b    is a cross-sectional top view of the diagram of  FIG. 3 a    according to an exemplary embodiment. 
         FIG. 3 c    is a side view of the PV module testing and conditioning system of  FIG. 3 a    according to an exemplary embodiment. 
         FIG. 4  is a side view of a portion of the PV module testing and conditioning system of  FIG. 3 a    according to an exemplary embodiment. 
         FIG. 5  is a method for testing and conditioning PV modules according to an exemplary embodiment. 
         FIG. 6  is a diagram of a PV module testing and conditioning system according to an exemplary embodiment. 
         FIG. 7  is a diagram of a PV module testing and conditioning system according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments that provide a system for inline testing and conditioning of PV modules while they are manufactured. These embodiments are described in sufficient detail to enable those skilled in the art to make and use them, and it is to be understood that structural, logical, or procedural changes may be made to the specific embodiments disclosed without departing from the spirit and scope of the invention. 
       FIG. 1  illustrates a bottom perspective view of a PV module  100  according to an exemplary embodiment. The PV module  100  may have any suitable geometry. For example, the PV module  100  may have a width of about 60 cm, a length of about 120 cm, a thickness ranging from 5 to 8 mm, and a weight of about 12 kg. The PV module  100  includes a plurality of layers between front and back covers that form a plurality of interconnected PV cells that generate electrical current from solar radiation. 
     The PV cells within the PV module  100  are electrically connected to a cord plate  110  attached to a back cover  120  of the PV module  100 . The cord plate allows external connections  112  and  114  to be connected to internal conductors of PV module  100 . As illustrated in  FIG. 2 , during manufacturing of the PV module  100 , positive and negative lead foils  232  and  234 , which are electrically connected to the PV cells, are brought out of the PV module  100  through a hole  230  in the back cover  120 . The positive and negative lead foils  232  and  234  are brought out near the front edge  280  of the PV module  100 . In a subsequent step in the manufacturing process, the cord plate  110  is attached to the back cover  120  and external conductors are electrically connected to the positive and negative lead foils  232  and  234  within the cord plate  110 . Positive and negative lead foils  232  and  234  may be formed of any suitable material such as, gold, silver, copper, aluminum, or other conductive metals. In one embodiment, the positive and negative lead foils  232  and  234  may be formed of conductive tape. 
       FIG. 3 a    illustrates a diagram of a testing and conditioning system (TCS)  300  according to an exemplary embodiment. The TCS  300  includes an enclosure  302 , a conveyor  310 , a testing and conditioning unit (TCU)  318 , and a system controller  330 . 
     The enclosure  302  has a box shape and includes a bottom  303 , a top  304 , a first opening  306  on one side and second opening  308  on an opposite side. The first and second openings  306  and  308  are large enough to allow the conveyor  310  and the PV module  100  atop the conveyor  310  to pass there through. The enclosure  302  is designed to limit access to the PV module  100  and other parts of the TCS  300  to prevent an operator or other object from conducting current applied to the PV module  100  during testing and/or conditioning. As illustrated in  FIG. 3 c    the enclosure  302  further includes first and second access doors  307  and  309  that are used to access the interior of enclosure  302  for maintenance. The access doors  307  and  309  allow an operator to remove broken modules or to repair components within the enclosure  302 . Additionally, the enclosure  302  may include solenoid-locking safety switches  390  to secure the access doors  307  and  309  and thereby secure the enclosure  302  during testing. The enclosure  302  may also contain a perimeter sensor that detects whether the access doors  307  and  309  are secure. The enclosure  302  is connected to and communicates with the control panel  335  through communication cable  352 , which in turn communicates with the system controller  330  through communication cable  350 . The enclosure  302  may provide information regarding the status of the enclosure  302  to the system controller  330  via the control panel  335 , such as, whether the perimeter of the enclosure  302  is secured. 
     The conveyor  310  passes through the enclosure  302  and through the first and second openings  306  and  308  in the direction of arrow  316  and supports a PV module  100 . The PV module  100  is positioned on the conveyor  310  with the leading edge  382  of the PV module  100  facing the opening  308 . Furthermore, the PV module  100  is positioned on the conveyor  310  with the PV module&#39;s  100  positive and negative lead foils  232  and  234  facing the top  304  of the enclosure  302  and the PV module&#39;s  100  front edge  280  facing into the page. A scanner  314  may be positioned outside the enclosure  302  and below the conveyor  310  to read an ID of the PV module  100  as it is brought into the enclosure  302 . The PV module  100  ID may be a bar code or any other computer readable identification system. 
     The movement of the conveyor  310  is, controlled by a conveyor controller  312 . The conveyor controller  312  operates the conveyor  310  to bring the PV module  100  into the enclosure  302  and align the PV module  100  with the TCU  318 . A presence sensor  366  located beneath the conveyor  310  and connected to the conveyor controller  312  is used to determine when the PV module  100  is aligned with the TCU  318 . The conveyor controller  312  also is connected to and communicates with the control panel  335  through communication cable  353 . The conveyor controller  312  sends status information to and receives commands from the system controller  330  via the control panel  335 . 
     The TCU  318  includes a contact unit  320  and a power unit  340 . The contact unit  320  has contact pads  324  and  325  that respectively contact the lead foils  232  and  234  of the PV module  100  during testing and conditioning of the PV module  100 . The power unit  340  provides an electrical bias to the PV module  100  and measure voltage and current on the PV module  100  during testing and/or conditioning of the PV module  100 . The electrical bias may be constant voltage, constant current, variable voltage, variable current, pulses of constant current, pulses of constant voltage, alternating constant or variable current and constant or variable voltage, or any combination thereof. In one embodiment, a relay may also be utilized with the power unit  340  to provide electrical bias to the PV module  100 . 
     The contact unit  320  is positioned within the enclosure  302  between the conveyor  310  and the top  304  of the enclosure  302 . The contact unit  320  includes a plunger switch  322 , first and second contact pads  324  and  325  (as illustrated in  FIG. 3 b   ), and an edge sensor  326 . The plunger switch  322  is used to sense the presence of a module  100  below contact unit  320  while the edge sensor  326  is used to align the contact pads  324  and  325  over the positive and negative lead foils  232  and  234  respectively of the PV module  100  in a direction perpendicular to the direction of PV module  100  conveyance during testing and conditioning of the PV module  100 . The plunger switch  322 , edge sensor  326 , and first and second contact pads  324  and  325  are further illustrated and described with respect to  FIG. 4 . A control panel  335  is provided to operate and control the contact unit  320 . The control panel  335  is also connected to and communicates with system controller  330  through communication cable  350 . The control panel  335  may also connect to the power unit  340  via communication cable  351 , contact unit  320  via communication cable  352 , and the sensors (e.g.  360  and  366 ), scanner  314 , and conveyor controller  312  via communication cable  353 . The contact unit  320  sends status information to the control panel  335 , and ultimately the system controller  330  and receives commands from the system controller  330  via the control panel  335 . 
       FIG. 3 b    illustrates a top view of the diagram of  FIG. 3 a    according to an exemplary embodiment with the contact unit  320  in a home position. The contact unit  320  resides in the home position during periods when the PV module  100  is not being conditioned or tested. In the home position, the portion of the contact unit  320  positioned closest to the conveyor  310  is maintained at least 2.5 inches from the conveyor  310 . This clearance distance prevents the contact unit  320  from scratching or otherwise damaging the PV module  100  when it is brought in and out of the enclosure  302 . When a PV module  100  is brought into the enclosure  302 , the conveyor  310  positions the PV module  100  so that the contact unit  320  is centered between the leading and trailing edges  382  and  384  of the PV module  100 . Centering the contact unit  320  between the leading and trailing edges  382  and  384  of the PV module  100  aligns the contact pads  324  and  325  with the lead foils  232  and  234  in the direction of PV module  100  conveyance. As mentioned above, the edge sensor  326  is then used to center the contact pads  324  and  325  and align them with the lead foils  232  and  234 . 
     Referring again to  FIG. 3 a   , the power unit  340  is located outside of the enclosure  302  and is connected to the contact unit  320  by positive and negative wires  344  and  346 . In another embodiment, the power unit  340  may be contained within the enclosure  302 . The power unit  340  supplies current and voltage to the PV module  100  by way of the contact unit  320  and positive and negative wires  344  and  346 . More particularly, the power unit  340  supplies current and voltage to the positive and negative lead foils  232  and  234  of the PV module  100  by way of the contact pads  324  and  325  of the contact unit  320 . When the power unit  340  is enabled by the controller  330 , current flows between the power unit  340  and the PV module  100 . When the power unit  340  is disabled by the controller  330 , current stops flowing from the power unit  340 . 
     The power unit  340  may operate in a constant current mode with a current set point ranging between 0 to 11.0 amps with an accuracy of +/−0.15 amps. The power unit  340  may also supply an adjustable voltage that ranges between 0 and 300 volts. In total, the power unit  340  may provide up to 3300 watts of power to the PV module  100 . In another embodiment, the power unit  340  may also operate in a varying current mode with a current set point ranging between 0 to 11.0 amps with an accuracy of +/−0.15 amps and a voltage ranging between 0 and 300 volts. Furthermore, in another embodiment, the power unit  340  may operate in a mixed mode and provide varying levels of current and voltage. 
     The power unit  340  further includes voltage sensor  347  and current sensor  348  used to measure the voltage and current within the PV module  100  during testing and/or conditioning of the PV module  100 . For example, in a testing mode, the power unit  340  may measure the voltage and/or current generated by the PV module  100  when the PV module  100  is exposed to light. In a conditioning mode, the electrical bias provided by the contact unit  320  to the PV module  100  during a conditioning event may be monitored by the voltage and current sensors  347  and  348 . Using voltage sensor  347 , the power unit  340  measures the voltage between the positive and negative lead foils  232  and  234  of the PV module  100 . In another embodiment, the power unit  340  uses the voltage sensor  347  to measure the voltage on a voltage divider that corresponds to the voltage between the positive and negative lead foils  232  and  234 . Using the current sensor, the power unit  340  measures the actual current flow within the PV module  100 . 
     The power unit  340  is connected to and communicates with the control panel  335  through communication cable  351 . The power unit  340  receives commands from the system controller  330  via the control panel  335  and the power unit  340  sends data, such as voltage and/or current measurements, and status information to the system controller  330  via the control panel  335 . 
     The TCS  300  may further include first and second temperature sensors  360  and  362  (as illustrated in  FIG. 4 ) within the enclosure  302 . The temperature sensors  360  and  362  are positioned above the conveyor  310  and are centered between the leading and trailing edges  382  and  384  of the PV module  100 . For example, as illustrated in  FIG. 4 , the first temperature sensor  360  is positioned one-quarter of the length  464  of the PV module  100  from the front edge  280  of the PV module  100  and the second temperature sensor  362  is positioned three-quarters of the length  464  of the PV module  100  from the front edge  280 . The first and second temperature sensors  360  and  362  are used to measure the temperature of the PV module  100  before, during, and after testing. In one embodiment, the temperature sensors  360  and  362  may be non-contact pyrometers. In another embodiment, the temperature sensors  360  and  362  may be contact sensors that move into and out of contact with the PV module  100 . The temperature sensors  360  and  362  are connected to and communicate with system controller  330  via the control panel  335  to send the temperature readings of the PV module  100 . 
     As illustrated in  FIG. 3 a   , the system controller  330  is connected to and communicates with various components in the TCS  300  through communication cable  350  and the control panel  335  according to one embodiment. In another embodiment, the system controller  330  may communicate with components in the TCS  300  using a wireless network, Bluetooth, or other means of communication. In yet another embodiment, the system controller  330  may communicate with some of the components in the TCS  300  using a wired connection and other of the components using a wireless connection. 
     The system controller  330  controls the operation of the TCS  300 , executes self-diagnostics, and may interface with a plant-wide communications network. In particular, the system controller  330  may support the TCS&#39;s  300  operational functions, diagnostic systems, process parameters, status reporting, program download functions, and program upload functions. To allow for self-diagnostics, the system controller  330  may include diagnostic software to allow for trouble shooting causes of process alarms. For example, the software may store alarm histories that include event details such as the type of alarm, the time stamp of the alarm, and the time stamp of the TCS  300  reset following the alarm. The diagnostic software may also allow for viewing and trouble shooting of machine functions through the network connection. 
     The data that is received by the system controller  330  from the TCS  300  may be collected, displayed, transmitted, and stored. For example, data concerning the PV module  100 , including testing and conditioning data, may be displayed on a console  398  to an operator. The data may also be transmitted and stored in a database  396 . The data may be transmitted to the database  396  by way of a network server. For example, in one embodiment, the server may be an OPC server and the database  396  may be an SQL database. Furthermore, the data may be stored in a process table within the database  396 . Within the table, an entry may be created for each PV module  100  that is processed by the TCS  300 . For example, module ID, electrical current set point, actual electrical current, start time stamp, end time stamp, start voltage, end voltage, start temperature, end temperature, and equipment status may be stored for each PV module  100 . 
     The data may be collected and continuously uploaded to the database  396  in real-time. Alternately, the data may be collected and stored locally within the system controller  330  and periodically uploaded to the database  396 . In one example, data may be uploaded at the end of each testing and/or conditioning cycle. The uploaded data may include raw data collected from the sensors. Alternately, the uploaded data may also include data processed by the system controller  330 . As described above, data may be uploaded from the system controller  330  to the database  396 . Data may also be downloaded from the database  396  to the system controller  330 . In one embodiment, the system controller  330  is a programmable logic controller. In another embodiment, the system controller  330  is a computer. 
       FIG. 4  illustrates a detailed front view of the contact unit  320  and the PV module  100  within the TCS  300  according to an exemplary embodiment. As illustrated in  FIG. 4 , the contact unit  320  is mounted on horizontal rails  470  and a vertical rail  472  to allow the contact unit  320  to move laterally and vertically. 
     The contact unit  320 , as illustrated in  FIG. 4 , is in an aligned position above the PV module  100 . To begin testing and/or conditioning of the PV module  100 , the contact unit  320  moves from the home position, into the aligned position, and then into contact with the PV module  100 . Specifically, the first and second contact pads  324  and  325  are moved into electrical contact with the positive and negative lead foils  232  and  234  of the PV module  100 . 
     To place the contact unit  320  into contact with the PV module  100  from the home position, the contact unit  320  first moves laterally, i.e. parallel to the back cover  120  of the PV module  100 , in the direction of arrow  490  along the horizontal rails  470  to the aligned position. The contact unit  320  moves laterally until either the edge sensor  326  detects the front edge  280  of the PV module  100  or the contact unit  320  reaches an end position along the horizontal rails  470 . If the end position along the horizontal rails  470  is reached, as determined by a horizontal position sensor  494 , the contact unit  320  returns to the home position and indicates to the system controller  330  that it was unable to detect the edge of the PV module  100 . If the edge sensor  326  detects the front edge  280 , the contact unit  320  stops moving laterally and commences to descend toward the PV module  100  along the vertical rail  472 . In one embodiment, the edge sensor  326  may be a photo eye sensor capable of identifying the location of the front edge  280  of the PV module  100  with an accuracy of 3 mm. In another embodiment, the edge sensor  326  may be another type of sensor. 
     The contact unit  320  descends toward the PV module  100  until the contact unit  320  reaches an end position along the vertical rail  472  as determined by a vertical position sensor  496 , such as a Hall Effect sensor. With the contact unit  320  at an end position along the vertical rail  472 , the first and second contact pads  324  and  325  are in contact with the positive and negative lead foils  232  and  234  respectively. The system uses the plunger  322  to verify that the contact unit  320  is on the PV module  100  and infers that first and second contact pads  324  and  325  are in contact with the positive and negative lead foils  232  and  234  respectively. The plunger  322  extends lower than the first and second contact pads  324  and  325  by a known distance  492  and is fixed to the contact unit  320  by a plunger spring  423 . As the contact unit  320  descends toward the PV module  100 , the plunger  322  contacts the PV module  100  before the first and second contact pads  324  and  325  contact the positive and negative lead foils  232  and  234 . As the contact unit  320  continues to descend with the plunger  322  in contact with the module  100 , the plunger spring  322  is compressed. A proximity switch sensor  498  detects the compression of the plunger spring  322 , which indicates that the contact unit  320  contacted the module  100 . The contact unit  320  then indicates to the system controller  330  that contact has been made. 
     In another embodiment, the contact unit  320  may use sensors to determine the vertical distance between the PV module  100  and the contact pads  324  and  325  and place the contact pads  324  and  325  into contact with the PV module  100 . Various devices may be used to move the contact unit  320  along the horizontal rails  470  and the vertical rail  472 . For example, in one embodiment, air cylinders may be used to move the contact unit  320 . In another embodiment, servos, an electric motor, or a hydraulic system may be used. Furthermore, different mechanics may be used to move the contact unit  320  horizontal and vertically. For example, air cylinders may move the contact unit  320  vertically, while an electric motor may move the contact unit  320  horizontally. In any event, the placement and design of the contact unit  320  should be controlled to limit the pressure applied by the contact unit  320  to the PV module  100 . For example, in one embodiment, the pressure applied by the contact unit  320  to the PV module  100  should be limited to 25 lbs of force over a 6 square inch area. 
       FIG. 5  illustrates a method  500  implemented by the TCS  300  to test and/or condition the PV module  100  inline during manufacture of the PV module  100  according to an exemplary embodiment. To begin, in step  505 , the system controller  330  waits to receive confirmation from the enclosure  302  that the doors  307  and  309  are closed and the enclosure  302  is secured. Once the system controller  330  confirms that the enclosure  302  is secured, in step  510 , the system controller  330  indicates to the conveyor controller  312  to bring the PV module  100  into the enclosure  302 . The conveyor controller  312  operates the conveyor  310  to bring the PV module  100  into the enclosure  302 . The PV module  100  is brought into the enclosure  302  after the back cover  120  of the PV module  100  has been installed and the lead foils  232  and  234  have been brought out of the hole  230  of the back cover  120  and folded back onto the surface of the back cover  120 . In one embodiment, the PV module  100  may be brought into the enclosure  302  from a laminator that installs the back cover  120 . To install the back cover  120 , the laminator typically heats the PV module to between 100 and 200 degrees Celsius. As a result, the PV module  100  enters the enclosure  302  with a temperature between 20 and 200 degrees Celsius. 
     As the PV module  100  enters the enclosure  302 , a previously read ID of the PV module  100  is sent to the system controller  330  so that the system controller  330  may customize the testing and/or conditioning for the individual PV module  100 . As the conveyor  310  brings the PV module  100  further into the enclosure  302 , the presence sensor  366  senses the PV module  100  and sends a signal to the conveyor controller  312  which stops the conveyor  310 . The PV module  100  is now aligned in the direction of PV module  100  conveyance beneath the contact unit  320  and above the temperature sensors  360  and  362  as illustrated in  FIG. 3 b   . The conveyor controller  312  then sends a signal to the system controller  330  that the PV module  100  is aligned. In step  515 , the system controller  330  commands the conveyor controller  312  to disengage the conveyor  310  so that no movement of the PV module  100  may occur during testing and/or conditioning of the PV module  100 . 
     In step  520 , the system controller  330  determines if the doors  307  and  309  are closed and if one or more start criteria for the testing and/or conditioning of the PV module  100  have been meet. In one embodiment, the start criteria may be programmed into the system controller  330  by the operator before hand. In another embodiment, the start criteria may be set by the operator using the console  398  in real time. In yet another embodiment, the operator may override programmed start criteria in real time using the console  398 . 
     In one embodiment, start criteria may include the temperature of the PV module  100  falling within a specified range, such as between 20 and 200° C. The system controller  330  may determine the temperature of the PV module  100  using the temperature sensors  360  and  362 . If the temperature of the PV module  100  is above 200° C., the system controller  330  may wait for the PV module  100  to cool before continuing. Additionally, if the temperature of the PV module  100  is outside the specified range, the system controller  330  may determine the start criterion has not been met. In another embodiment, the start criteria may include the TCS  300  having an allotted amount of time, such as between 0 and 10 minutes, to perform the testing and/or conditioning during the manufacturing process. For example, the start criteria may indicate that 5 minutes is needed to perform testing and/or conditioning during the manufacturing process. If the system controller  330  determines that there is only 3 minutes to perform the testing and/or conditioning, then the start criteria would not be met. 
     If the start criteria cannot be met, the method  500  advances to step  580 . Otherwise, in step  525 , the system controller  330  commands the contact unit  320  to place the contact pads  324  and  325  into contact with the lead foils  232  and  234  as explained with respect to  FIG. 4 . If the contact unit  320  is unable to place the contact pads  324  and  325  into contact with the lead foils  232  and  234  then the method  500  advances to step  570 . If contact between the contact pads  324  and  325  and the lead foils  232  and  234  is established then, in step  530 , the system controller  330  commands the power unit to output power. 
     Once the power unit is enabled, in step  540 , the electrical contact between the contact pads  324  and  325  and the lead foils  232  and  234  is verified. To verify the electrical contact, the system controller  330  commands the power unit  340  to supply an electrical bias to the PV module  100  through the contact pads  324  and  325 . For verification, a low current, for example 0.25 amps may be used. For testing and/or conditioning purposes, the current supplied by the power unit  340  may range between 0 and 11 amps and the voltage may range between 0 and 300 volts. After the electrical bias has been applied for a set amount of time, for example, 5 seconds, the power unit  340  measures the current and voltage of the PV module  100  and sends the data to the system controller  330 . The system controller  330  compares the measured current and voltage to set thresholds to determine if the PV module  100  is faulty or if the contact between the contact unit  320  and the PV module  100  is not sound. For example, in one embodiment, a PV module with a measured current below 20 milliamps or a measured voltage below 20 volts would be considered faulty or as having an unsound contact between the PV module and the contact unit  320 . If the measured current and voltage are found acceptable, the method  500  advances to step  550 . If either of the measured current and voltage levels is found unacceptable, the method  500  advances to step  560 . Furthermore, if during step  540  the system controller  330  receives data indicating that the enclosure  302  is no longer secured, the method  500  advances to step  560 . 
     In step  550 , the PV module  100  is tested and/or conditioned using electrical bias provided by the power unit  340  as controlled by the system controller  330 . The electrical bias applied to the PV module  100  during the testing and conditioning may be constant, alternating, pulsating, or any combination thereof. Additionally, the system controller  330  may adjust the testing and/or conditioning procedures and conditions based on information known about the PV module  100  being tested and on feedback received during the testing and/or conditioning procedure. For example, data on the PV module  100  may be collected during the manufacturing processes that occur before the testing and/or conditioning of the PV module  100 . This collected data may then be used when selecting parameters for the testing and/or conditioning of the PV module  100 . For example, information relating to a vapor deposition process for the PV module  100 , such as the temperature and chemical composition of the melt material, may be stored in the database  396 . Based on this stored data, the testing and/or conditioning may be adjusted. Furthermore, the system controller  330  may adjust the testing and/or conditioning procedures and conditions based on real time operator input received through the console  398 . 
     Current and/or voltage measurements may be taken during the testing or conditioning process by the power unit  340  and sent to the system controller  330 . The measurements may be taken at set time intervals. For example, the measurements may be taken every 15, 30, or 60 seconds, or after any other reasonable time period. Once testing and/or conditioning is commenced, the system controller  330  also monitors stop conditions to determine when the testing and/or conditioning should end. Stop conditions may include measurable quantities, such as, the temperature of the PV module  100  falling below a set point, the voltage on the PV module  100  rising above a set point, the duration of the testing and/or condition lasting for a predetermined period. If one of the stop conditions is fulfilled, the method  500  advances to step  560 . The stop conditions may be preset or determined in real time by the operator. Furthermore, if during step  550  the system controller  330  receives data indicating that the enclosure  302  is no longer secured, the method  500  advances to step  560 . 
     In step  560 , the system controller  330  commands power unit  340  to stop providing power. Then in step  570 , the system controller  330  commands the contact unit  320  to return to the home position. In step  580 , the system controller  330  sends a signal to the conveyor controller  312  to move the PV module  100  out of the enclosure  302 . The conveyor controller  312  operates the conveyor  310  to bring the PV module  100  out of the enclosure  302 . It should be understood that additional steps may be performed in the method  500  as described. Furthermore, some of the steps may not be performed, or the steps described may be performed in a different order. 
     The TCS  300  may include more than one TCU  318  to allow the TCS  300  to process more than one PV module at a time. For example, as illustrated in  FIG. 6 , the TCS  600  may include five TCUs  318  spread along the conveyor  310  to enable the TCS  600  to test and/or condition five PV modules  100   a - 100   e  simultaneously according to an exemplary embodiment. In this embodiment, the five PV modules  100   a - 100   e  are brought into the enclosure  302  at the same time along the conveyor  310 . The system controller  330  controls the testing and/or conditioning of each PV module  100   a - 100   e  individually and may change the testing and/or conditioning performed on an individual PV module  100   a - 100   e  based on the data previously collected for the PV module  100   a - 100   e  or based on the information collected during the testing and/or conditioning of the PV module  100   a - 100   e . Furthermore, the system controller  330  may change the testing and/or conditioning for each individual PV module  100   a - 100   e  based on input from the operator. 
     The TCS  300  operates to test and/or condition every PV module  100   a - 100   e  independently. For example, if one of the five TCUs  318  is unable to locate or contact its corresponding PV module  100   a - 100   e , the remaining PV modules  100   a - 100   e  are tested and/or conditioned. Likewise, if one of the PV modules  100   a - 100   e  fails the initial testing, the remaining PV modules  100   a - 100   e  are tested and/or conditioned. Additionally, the TCS  300  continues testing and/or conditioning each PV modules  100   a - 100   e  until a stop condition is fulfilled for that individual PV module  100   a - 100   e . For example, if the PV module  100   e  has met its stop condition, the testing and/or conditioning on the PV module  100   e  will stop while the remaining PV modules  100   a - 100   d  continue to be tested and/or conditioned. The remaining PV modules  100   a - 100   d  will continue to be tested and/or conditioned until they fulfill a stop condition. In this example, after fulfilling the stop condition, the PV module  100   e  performs steps  560  and  570 . When all five PV modules  100   a - 100   e  have fulfilled their stop conditions and completed steps  560  and  570 , the TCS  300  performs step  580  and the testing and/or conditioning of the PV modules  100   a - 100   e  is completed. 
     In another embodiment, the TCS  300  operates to test and/or condition each PV module  100   a - 100   e  dependent on the condition of the remaining PV modules  100   a - 100   e . For example, once the stop condition for one of the PV modules (e.g.  100   a ) is fulfilled, testing and conditioning for every module  100   a - 100   e  may stop. Likewise, in this embodiment, the TCS  300  may not perform testing and conditioning on any of the PV modules  100   a - 100   e  if one of the TCUs  318  is unable to locate or contact one of the PV modules  100   a - 100   e.    
     A system  700  may also be implemented where multiple TCSs  600  are operated in parallel. For example, as illustrated in  FIG. 7 , the system  700  may include eight TCSs  600   a - 600   h  operating in parallel according to an exemplary embodiment. The system  700  may simultaneously test and/or condition forty PV modules individually periodically, for example, every ten minutes. In this embodiment, each of the TCSs  600   a - 600   h  are controlled by a single system controller  730 . Furthermore, each of the TCSs  600   a - 600   h  has a console  398  that allows an operator to control the testing and conditioning of each PV module  100  within the individual TCSs  600   a - 600   h . Additionally, the TCSs  600   a - 600   h  may operate independently of each other so that the conditions and situations in one TCS  600   a - 600   h  does not affect the operation of the remaining TCSs  600   a - 600   h . In another embodiment, a system controller may be used to control and operate each TCSs  600   a - 600   h  individually. In yet another embodiment, a single console  398  may be used for all of the TCSs  600   a - 600   h . Other embodiments may use more or fewer TCSs as required by the system  700 . 
     While embodiments have been described in detail, it should be readily understood that the invention is not limited to the disclosed embodiments. Rather the embodiments can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described without departing from the spirit and scope of the invention.