The EPA’s Clean Power Plan ruling to reduce greenhouse gas emissions will require utilities to submit plans for reductions by 2016. The ruling offers the solar industry a unique opportunity to play a key role, according to motion solutions manufacturer Dunkermotor.
Sensing an opportunity, Dunkermotor has redefined its Solar Tracker Motor (STM) portfolio to cater to the PV, CPV and CSP market segments more distinctly. The company recently outlined its offering in a presentation. Below are some takeaways.
Solar Tracker Motors
Dunkermotor aims to produce rugged equipment that lets owners achieve the lowest total cost of ownership. The company has three primary solutions: STM for PV, CPV and CSP.
The company’s most economical solution to single-axis PV trackers are based on DC or AC gearmotors that are designed for a life of 20 or more years and require no maintenance.
The most integrated solutions for Concentrated PV trackers feature all-in-one motor-gear-drive packages with optional integral inclinometer. The system lets users take advantage of distributed control architecture.
Concentrated Solar Power applications require medium to great accuracy and constant tracking. STM CSP solutions feature all-in-one motor-gear-drive packages with optional high-resolution absolute encoders.
The below graphic shows Dunkermotor’s line of STM products:
Inclinometer Options
A new feature from the company is the ability for users to choose whether inclinometers are either directly connected to the STM motors or are part of the motors themselves.
Often, solar trackers require an inclinometer to be mounted onto their frames to precisely measure their actual position angle. The inclinometer data is then transmitted to the tracker’s main controller where the position loop is closed. The disadvantages of such configuration are mainly the high cabling costs and the high processing power that is required of the main controller.
A more reliable and cost effective design can be achieved by using Dunkermotoren’s All-in-One brushless motors with integral motion controller and direct inclinometer input. The inclinometer data is directly processed by the motor as it closes its own position loop, reducing bus traffic and allowing bus capacity to be fully utilized.
When motor and tracker are moving together, the control and mechanical designs can further be streamlined by using Dunkermotoren’s All-in-One brushless motors with integral motion controller and on-board inclinometer.
In this approach, the inclinometer is enclosed within the motor housing and directly communicates with the motor’s embedded motion controller, with no external cable required. This design is by far the most cost effective concept for solar trackers.
Features From Dunkermotor
Dunkermotor touts a few features exclusive to its STM technology. Advanced lubrication, optimized for wide temperature ranges up to -40 to 85 C, assists in low speed/high torque operating conditions.
Components feature a high degree of protection against water and dust with rating up to IP67. All STM solutions include pressure equalizing protective vents.
An on-board computer allows for distributed control, executes mission critical functions and provides deep diagnostics.