Yokogawa Australia has released the HXS10-SolStation controller. It controls the actuation systems that move heliostats (reflectors), solar concentrating dishes, solar troughs and photovoltaic panels. The HXS10 helps maximise power generating efficiency by controlling the angles of heliostats and solar panels so they stay pointed at the sun as it moves across the sky.
The HXS10 combines Yokogawa’s measurement and control technologies. The measurement system is inherited from Yokogawa’s recorders that are used in mission critical applications throughout the world; while the control engine comes from Yokogawa’s loop controllers.
The system was recently exhibited at Solar Power International 10 in Los Angeles (October 2010) and is being considered for implementation in landmark projects in Australia.
One of the driving forces for solar thermal and photovoltaic power generation systems has been their ability to generate electricity during the daytime hours, when demand is at its highest. In a solar thermal power generation system, sunlight is concentrated onto a receiver that uses the heat to turn water into steam, which rotates a turbine and generates electricity.
The technology is equally well suited to the latest water-free solar plants being developed in Australia as the sun-tracking needs are identical. By controlling the angle of the heliostat so it tracks the movement of the sun, it is possible to precisely focus the sunlight onto the receiver.
For photovoltaic power generation systems, though most solar panels used today are of the fixed type, power-generating efficiency can be improved if panels are kept directed at an optimal angle towards the sun. Control technologies that can precisely orient the heliostats and panels to follow the movement of the sun are crucial.
By utilising its reliable control technologies, Yokogawa has developed the HXS10 to control the actuation systems of solar thermal and photovoltaic power generation systems. Based on the facility location, date, and time, the HXS10 calculates the position of the sun through a high-resolution (64-bit) NREL solar position algorithm, and operates motors or hydraulic actuators to adjust the angle of the heliostats and solar panels so they stay pointed toward the sun.
The HXS10 function block features precise time synchronising using an SNTP (Simple Network Time Protocol), which allows the HXS10 to be linked to a master PC clock, or an atomic clock via the Internet for truly precise time tracking to fractions of second.
The system is designed for use on single tracking control for small Photovoltaic systems on remote mine sites through to major large scale solar power plants.
The HXS10 is designed specifically for the control of solar tracking systems. Compared to general-purpose controllers such as PLCs, this controller has lower initial costs and requires less engineering time.
The HXS10 is built of environmentally resistant and durable components and can withstand temperatures ranging from –20°C to +70°C. This product is suitable for the control of solar power generating facilities installed in deserts and other harsh locations.
The HXS10 has a communication function that allows it to be monitored by a host system in a central control room. To eliminate communication traffic overload and create a more secure and stable communication environment, each HXS10’s communications can be routed to the host system via another HXS10 unit.