AMETEK Programmable power systems simulate PV arrays' inputs to inverter and effects of local load patterns and sink/source connection to grid. The company's new test software aids compliance testing for standards and regulations in effect and in draft around the world.
AMETEK Programmable Power announced a complete system for testing the power performance and standards compliance of PV (photo-voltaic) inverters, in an initiative called ‘Surrounding the Inverter'.
The company's programmable power system for PV inverter testing enables developers, manufacturers, independent test houses and others to simulate the effects on the inverter of arrays of solar panels, the connection to the utility grid and simulated customer loads. Repeatable, accurate power simulations help manufacturers ensure that inverters maximize the efficiency of solar arrays whilst staying compliant with the growing body of government regulations and industry standards.
AMETEK's ‘Surround the Inverter' concept consists of five elements:
- TerraSAS Programmable Solar Array Simulator simulates changing irradiance and temperature conditions, and enables testing of MPPT (Maximum Power Point Tracking) performance
- MX Series programmable, bi-directional power source/sink simulates the interconnection of the inverter with the grid. It simulates the utility power variability (voltage, frequency, harmonic distortion) necessary to test the inverter's ability to source energy to the grid. Also tests anti-islanding capability.
- An AC programmable load simulator, such as the 3091LD, will simulate various products connected to the main power panel at the customer's premises
- Dedicated PV Simulation Software for full inverter testing
- AMETEK also supplies the Elgar BSS (Battery Simulation System) for testing inverter behavior in off-grid applications
Using the latest version of AMETEK's testing control software, users are able to model the effect on the inverter of interactions between different parts of the power system. For instance, variations in the quality of the power source from the grid (simulated by the MX Series) can affect the ability of the inverter to efficiently convert the variable power input from the solar array (simulated by TerraSAS). Only by deploying a complete test system that models the behavior of the inverter under the effect of all possible combinations of input and output conditions can engineers optimize inverter performance and confidently issue product warranties.
Programmable, with a high input bandwidth, and extremely accurate, AMETEK's instruments can simulate any conditions required for the testing of reliable PV inverters. Eric Turner, Product Manager of AMETEK Programmable Power, said: ‘Regulatory requirements for PV inverters are constantly changing, but inverter manufacturers also have to respond to changing utility and end-user expectations. For inverter manufacturers to update and enhance their product designs at this fast pace, they require adaptable, capable and accurate test systems that will let them simulate the full range of conditions their inverters must perform in.
‘With its software control system for PV inverters, AMETEK Programmable Power provides a testing framework that is constantly updated to take account of the latest regulations and standards, often before they are even ratified.'
AMETEK has developed a comprehensive system for testing PV inverters in response to the rapid growth in the installed base of solar arrays, and the consequently larger impact of PV power inputs on the grid. The growing importance of solar power has in turn led governments, utilities and standards bodies to formulate new rules and directives governing the connection of PV devices to the grid, and the performance of PV inverters under a wide range of conditions. New grid connection rules include provisions for anti-islanding, which govern the behavior of inverters in the event of a grid power-down; and new industry measures support improved MPPT methods based on measurement of grid-induced ripple current and voltage.
Effective testing of inverters therefore requires the implementation of complex power routines that mimic effects such as grid frequency fluctuations, blackouts, weather variations causing rapid changes in insolation and temperature, and extreme load power profiles caused by the powering-up of equipment such as TVs, microwave ovens and PCs.
The programmable power instruments provided by AMETEK - TerraSAS, MX series, BSS and AC loads - can simulate all such power events. Using the control software provided by AMETEK, users can monitor the performance of an inverter under the effect of interactions between any two or all three of the instruments.
For more information about the test system, contact AMETEK Programmable Power sales at www.programmablepower.com
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