Product Overview

Solar trackers come in many different configurations, and it can be difficult to match a tracker to a given controller. The first step to consider is the tracker site:

  • Small; a stand-alone tracker application is typically where one or two trackers are constructed at one site. The controller software is configured for each tracker to be autonomous.

  • Medium; a tracker farm is the construction of multiple trackers at one site. A master controller is used to manage a domain of slave control systems.

  • Large; for large commercial or utility scale fields, multiple master controllers will be used to manage multiple domains.


There are three dominant solar tracker types:

  • Single-Axis tracker where the axis is typically in the North/South direction. Some sites may be geographically restricted such that the axis may have a yaw-offset. Today, single axis trackers are classified as either:

    • A Row-Tracker is a single row moved by a single actuator.

    • A Block-Tracker is single large actuator linked to multiple rows.

  • Dual-Axis trackers come in two types:

    • Traditional Azimuth and Elevation axis

    • East/West-Roll and North/South-Tilt axis


Finally, there is the actuator motor types such as:

  • Low power, up to 100W, 24VDC, or sometimes 12VDC, motors.

  • Medium power, up to 250W, 24VDC

  • High power, up to 10KW, 480VAC/3ph


Regardless of the solar tracker type and field, Lauritzen Solar Tracker Controllers can always be used.

CX3 - General-Purpose Solar Tracker Controller

Lauritzen General Purpose Solar Tracker ControllerThe CX3Px platform is designed specifically to serve the solar industry for solar tracking applications. It is capable of withstanding extreme temperatures, as well as continuous temperature cycles. Electrically it is designed to withstand voltage spikes on both supplies and control inputs, short circuit and thermal protection, and extensive diagnostic indicators.

Motors - The CX3 is capable of driving actuators with DC motors from 12VDC through 24VDC, and 3ph AC motors with an external Variable Frequency Drive. Actuator feedback can be either motor encoder or external inclinometer, and limit switches can be either implicit, external, or absolute.

One Platform, Multiple Applications – The CX3 controller is delivered pre-loaded with software depending on its final application. The following software configurations are available:

  • SCX, a Stand-Alone version ideal for 1 to 2 tracker installations

  • FMCX, a master controller with Modbus/RS485 interface.

  • TMCX, a slave controller with Modbus/RS485 interface.

  • FWCX, a master controller with wireless interface.

  • SLV_SECTION, a slave controller with wireless interface.

Power Supply - Power is usually supplied from an AC powered power supply, but Solar PV string power can also be used for a DC-to-DC power supply. Integrated battery management is available in applications requiring battery backup power.

Digital Inputs - Additional inputs are available for wind measurement, analog measurement, and digital inputs to force operational states such as Manual Storm and Clean modes.

DX3 - A Single-Axis Tracker Controller

Lauritzen Single-Axis Solar Tracker ControllerThe DX3Px platform is designed specifically to serve the solar industry for single-axis solar row-tracking applications. Together with an external Variable Frequency Drive, it can also be used for block tracker applications. It is compact and component count has been reduced to the absolute minimum while maintaining all features required of a tracker controller.

Feature list:

  • Tracking based on calculated solar position.

  • Integrated inclinometer reducing cable count.

  • Support for external inclinometer in case controller is mounted in a static enclosure.

  • 12-24VDC operating voltage.

  • Support for up to 240W DC motors with smooth start and stop.

  • Short circuit detection and thermal management.

  • Intra-field communication via Modbus/RS485 or wireless.

  • Remote management via Master controller.

  • Support for external limit switches.

  • Support for local Master Stop switch.

Software Options:

  • TMDX/TWDX – Modbus slave

EX3 - A Triple Single-Axis Tracker Controller

Lauritzen Triple Single-Axis Solar Tracker ControllerThe EX3Px platform is designed specifically to serve the solar industry for large scale single-axis solar row-tracking applications. Together with an external Variable Frequency Drive, it can also be used to drive a single block tracker. It is compact and component count has been reduced to the absolute minimum while maintaining all features required of a tracker controller.

Feature list:

  • Tracking based on calculated solar position.

  • Triple external inclinometer inputs.

  • 12-24VDC operating voltage.

  • Support for up to 240W DC motors with smooth start and stop.

  • Short circuit detection and thermal management.

  • Integrated Battery Management System.

  • Intra-field communication via Modbus/RS485 or wireless.

  • Remote management via Master controller.

  • Support for local Master Stop switch.

Software Options:

  • TMEX – Modbus slave

  • TWEX – Wireless slave

IXYZ1 - A Digital 3-Axis Inclinometer

 3-Axis Digital Inclinometer The IXYZ inclinometer is designed specifically for the solar industry, but could also be used in other applications. The IXYZ is a 3-dimensional inclinometer which is based on MEMS (Micro Electromechanical System) technology. It features a robust data protocol, voltage supply, and daisy chain feature when operating multiple inclinometers. It can withstand a wide temperature and voltage supply range.

Features:

  • RS232 interface, daisy chain capable

  • Low latency protocol when daisy chained.

  • Data compression, and error reporting with CRC16 data check

  • Automatic axis resolution reported as pitch and roll.

  • Integrated voltage polarity protection

  • IP65 rated enclosure, outdoor rating.

  • Wide operating temperature range

  • Accurate to within +/- 0.1-degree, angle reported in resolution of 0.01 degree.

Software Overview

All controllers are delivered with ready-to-go communication software which enable full remote management. All tracker application customization is done via user parameters. The parameters can be set via a controller integrated webserver, and via a cloud server.

Main solar tracker controller features:

  • Calculated targeting from geographic location and local time together with tracker positioning feedback.

  • Motor servo current, PWM frequency, acceleration control.

  • Motor encoder termination control.

  • Storm detection via parameterized wind threshold settings.

  • Operational range limit.

  • Target coordinates for Stow, Clean and Storm positions.

  • Fault handling.

Main remote management features:

  • Instant tracker status.

  • Transfer and presentation of tracker events.

  • Transfer and presentation of tracker data sampling.

  • Defining controller parameters.

  • Compilation and dispatch of controller commands.

  • Software update.

Local management via the integrated webserver features:

  • Instant tracker status.

  • Dispatch of controller commands.

  • Defining controller parameters.

Software for Stand-Alone Tracker

A Single Dual-Axis Tracker with a Lauritzen SCX Controller The stand-alone solar tracker software, is designed to operate a single dual-axis or two single-axis solar trackers. It is based on the CX3 platform and packaged with a set of software modules to make it a complete solar tracker controller solution. It may operate in a field of other SCX managed trackers; however, each unit is operated and managed individually.

Tracker Targeting: The solar position is calculated based on the geographic location and time of day. With a known solar position, the tracker target is determined based on criteria such as optimum solar while maintaining tracker operational limits.

Operational Aspects: When the Sun is below the horizon, the controller will move the tracker to a configurable stow position. In areas with snow conditions, this position is set at an angle where snow-buildup would be minimized, while in non-snow locations a more horizontal position is usually preferred.

Wind Handling: The tracker controller will typically operate with the input from an anemometer which is used to detect high wind-speeds. Three wind-speed thresholds are defined for safe tracker operation:

  1. Instantaneous wind-speed beyond which a storm condition is triggered.

  2. Average wind-speed beyond which a storm-condition is triggered.

  3. Instantaneous wind-speed beyond which dual-axis azimuth operation is undesirable.

Once a storm condition has been triggered, the tracker is brought to a predefined storm-position, by moving elevation first, followed by azimuth – if permitted.

Fault Handling: Errors can occur in electro-mechanical systems, and the SCX incorporates a configurable Fault Handler for how to automatically recover, or in case of failure, in which state to leave the non-operational tracker.

Local Control: Two additional input methods can be enabled for local control. One is the Clean/Storm mode switch used to force the tracker to the pre-defined storm-position or clean-position. The other is the loss of AC-power input which will force the tracker to storm-position and cease operation until AC-power has been re-established. The controller may also be connected to an energy meter – used to measure performance of the local PV system.

Networking: The SCX stand-alone controller may operate autonomously without use of a network/Ethernet connection, or it may be connected to the Lauritzen Valhalla server for remote monitoring and control. TCX2 includes both a local webserver for monitoring of tracker status and iPhone interface to help field technicians during installation.

Solar Tracker Master Controller

 Ethernet and Master/Slave Illustration The Solar Tracker Master Controller, together with a collection of Solar Tracker Slave Controllers, offers an ideal solution for the combination to be used in commercial solar tracker fields where multiple trackers are deployed. Each controller, including the master unit, can manage one, two or three trackers depending on controller type.

The Master Controller Software incorporates two software packages in one:

  1. A solar tracker controller module, and

  2. A field management module.

The solar tracker module is nearly identical to the one found in the SCX standalone system, including fault handling. The field management module incorporates field management such as:

  • Distribute weather, and manual storm/clean events from master to field.

  • Being able to place individual trackers on standby.

  • Collect and relay operational-data and event packages to remote server.

  • Relay or distribute remote server's field commands.

  • Provide gateway connection for real-time diagnostic console access.

  • Field wide software updates

 Cleaning Solar Panels with field in Clean ModeDepending on the layout of a solar tracker field, it may be difficult to route an Ethernet connection to a tracker containing a master controller. In that case, a Master Controller configured as a Gateway may be used. The unit is typically located along the field periphery, or adjacent to a central inverter. A Gateway Master Controller can connect to 25 units, whereas we Master Controller operating its own tracker may connect to 24 slave units.

Field maintenance is easily done via local master controls such as:

  • Force trackers into Clean position.

  • Force trackers into Storm position.

  • Force trackers in Service Mode.

A Master Controller may operate autonomously without use of a network/Ethernet connection, or it may be connected to the Lauritzen Valhalla server for remote monitoring and control. When connected to the server, interval captured data, events and status is periodically transported to the server for further analysis.

Hardware Platform Suitable for Master Software:

Solar Tracker Slave Controller

 Row Trackers with Slave Controllers The Slave Controller software can with its limited communication scope is reduced to focusing on tracker operations. It contains all the operational tracker functionality as found in the SCX Stand-Alone software, as well as a small module for either:

  • RS485/Modbus

  • Wireless

A domain of slave controllers within one master will all operate with the same parameter set as defined on the master. For this reason, the type of slave controllers must be uniform throughout a single domain.

 Block Trackers with Slave ControllersThe master continually broadcasts weather information to its domain of slave controllers. If a slave is defined to consider the weather information, it will enter Storm mode if a storm condition is broadcast. A given slave unit will also enter Storm mode is the communication link to the master is lost.

Hardware Platforms suitable for Slave Software:

Solar Tracker Fault Handling

Past experience has taught us that our controllers rarely fail, but electro-mechanical components, on the other hand, do! The electro-mechanical failures typically fall within the following categories:

  • Water penetration into motors, switches and/or sensors

  • Water and/or dust penetration into gears or other internal actuator components

  • Wind damage to internal gears

  • Broken switches due to poor switch placement or faulty hydraulics

  • Broken electrical circuits due to lose electrical connections, or poor cable routing.

  • Overpowered systems caused by storm/high wind events.

Often failures initially appear to be random and momentary, but over time they become permanent. Our early control systems simply aborted tracking upon fault detect. Since then, we have learned that certain failures should be retried depending on operational circumstances. To better manage the variety and consistency of faults, the latest systems incorporate a fault handling module which classify faults into the following categories:

  • Target Finder Faults

    • Maximum Travel

    • Stuck limit switch

    • Maximum deviation

  • Motor & Encoder Faults

    • Stuck motor

    • Encoder error

    • Unexpected movement

    • No motor present (disconnected motor)

    • External fault

  • Hardware (electronics) Errors

    • Maximum temperature

    • Maximum current

  • Inclinometer Errors

    • Inclinometer error

    • Inclinometer polarity error

For each categorized fault, one can specify the following recovery actions.

  • Do not recover.

  • Limited retry.

  • Unlimited retry.

  • Disable drive and continue tracking with remaining channel.

  • Enter Service-Mode

In addition to the standard recovery actions, the fault handler may also be configured to allow fault overrides in case of storm conditions.

Product Design and Manufacturing at Lauritzen Inc.

All our hardware products are designed by our staff and meet a rigorous set of operational requirements. When we decided to source our own designs, one of our goals was to be ROHS compliant. Strictly speaking, RoHS compliance is not required for the US market, but we care about the environment and it is important to us to set an example among US electronics manufacturers.

Our manufacturing is outsourced to established local Silicon Valley vendors who have demonstrated a history of quality work. Our circuit boards are manufactured by Sierra Circuits Inc. and assembly is done with the latest state-of-the art SMD equipment at Meritronics Inc.. Both vendors are ISO9001 certified and have been suppliers to Silicon Valley high-tech companies for many years.

All our product testing is automatic, and we have a complete automated assembly-to-test record of every product that leaves our premises.

Fully automated Surface Mount Technology is used for all PCB assembly. Automated application of solder paste Automatic Pick and Place of components
Components have been placed and awaiting solder paste reflow Transfer to reflow oven Automated solder reflow is used after thermal profile has been established with prototype PCB.
All controllers undergo 20-hour temperature cycle while under electrical test as part of standard Quality Control procedure. Automatically generated test data from burn-in testing is stored for possible future failure detection and analysis. Access to X-Ray microscopic camera to analyze potential PCB or assembly failures.

Warranty and Monitoring

The Lauritzen Control System Philosophy is for all deployed systems to attain a long maintenance free life. A key component to this goal is remote connectivity as it will clearly indicate what and when something happened. Having access to such operational feedback is critical to improving product design by understanding field failures.

All products are initially covered by a Limited Warranty for a limited duration. With subscription to remote monitoring, the Limited Warranty is automatically extended for as long as Remote Management subscription is maintained.