TerraSAS High-Performance 600V PV simulator

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1 Background AMETEK Programmable Power has been involved with Power Bus simulation for over 35 years in the aviation, satellite, and transportation industries. This experience has been specifically focused at producing power bus behavior that mimics real-life occurrences and situations. With this capability, product development and test engineers can validate their designs with a very high confidence that these products will operate reliably under all circumstances. AMETEK has been building PV simulators capable of high performance programmed IV characteristics since Of utmost importance, these TerraSAS PV simulators are specifically designed to mimic the behavior of a terrestrial photovoltaic power source and do so with sufficient bandwidth to keep up with the advanced MPPT algorithms in use with today s inverters. TerraSAS Technical Approach TerraSAS PV simulators are available in three basic designs optimized to serve the specific needs of three PV inverter types. Type 1: For use with string inverters that contain transformer isolation at or below 600Vdc Voc Type 2: For use with string inverters that do not contain transformer isolation and are capable of 1000Vdc Voc. Type 3: For use with panel-based microinverters or optimizers at or below 80Vdc Voc. Type 1: 5/10/15 KW, 600Vdc Although the TerraSAS has its basis in a long pedigree of spacecraft IV curve emulation, extensive analysis and testing has been performed on many PV inverters. We have created a power module that both meets the performance needs of the terrestrial solar power market while providing it with value and economy. The TerraSAS power module pictured provides complete isolation between the Inverter and the power mains for safety and the fastest tracking capability of any programmable-behavior power supply. Many factors were taken into consideration; not the least of which was assuring that the MPPT tracking performance of the TerraSAS would keep up with the existing inverter designs and new algorithm trends aimed at increasing efficiency. Our objective is to track the IV curve as the inverter seeks the maximum power point. Whilst seeking the MPP, the TerraSAS power supply must maintain complete adherence to the programmed IV curve under all conditions so that the results from qualification tests using our TerraSAS can be relied on as accurate. If the power source does not track the IV model, then the input power to the inverter and voltage/current relationship does not meet the input criteria rendering the data from these tests and resultant certification suspect.

2 600V PV simulator specifications DC Output Open Circuit Voltage, Voc: 1 600VDC Short Circuit Current, Isc: 0 8.3A per chassis (5kW) A per chassis (10kW) 0 25A per chassis (15kW) Maximum output power 4.25 kw (5kW) at fill factor kw (10kW) kw (15kW) Output isolation Output leakage Tracking speed Accuracy Sampling resolution Curve Resolution Profiles resolution Curve equations ±600 Vpk, positive or negative output to chassis ground, continuous Output to chassis ground, DC : < Vdc Output to chassis ground, AC : < 5 200Vpp, 60Hz (5kW) < 7 200Vpp, 60Hz (10kW) < Vpp, 60Hz (15kW) Compatible with inverters sweeping the MPP at up to 200 Hz. Voltage programming and readback: ±0.2% of full scale voltage Current programming and readback: ±0.5% of full scale current Voltage and current are synchronously sampled by two independent 16-bit A/D converters at 200kS/s. 1,024 points. Each point represents a single voltage / current point on the IV curve. The PV simulator interpolates the 1,024 points in its curve memory with 16-bit resolution, delivering an actual curve resolution of 65,536 points. There is no limit to the profile length. One-second profiles for a full day of simulation are typically 50k points. The simulator interpolates between points 128 times per second, delivering smooth voltage and current waveforms that closely resemble real solar arrays under cloudy conditions (requires TerraSAS software) Equations used to calculate and translate the IV curves are found in Appendix A1 and A2 of the publication Performance test Protocol for Evaluating Inverters Used in Grid-Connected Photovoltaic System, October 2004, Sandia National Labs. PV Array Parameters Irradiance level: 0 to 1999 W/m 2 Temperature value: -100 C to +100 C Voltage level: 0 to 600VDC Current level: 0 to 25A (15kW) Voltage and power temperature coefficients: ±1.99%/ C Expansion Available I/O Unrestricted expandability, allowing total system power above 1MW Ethernet: TerraSAS software proprietary high-speed link. Analog Irradiance/Temperature inputs: allow to adjust the IV curve in real time based on two external analog signals. Trigger input: allows execution of an irradiance/temperature profile in sync with external equipment. Useful for accurate energy measurements using external power analyzers. SCPI interface: through TerraSAS software

3 600V PV simulator specifications, continued Remote sense Input Nominal Voltage Input Frequency Power Factor Protection (typical) OVP Accuracy OVP Resolution Output noise Efficiency Stability Temperature Coefficient Operating Temperature Storage Temperature Humidity Range Altitude Cooling Maximum line drop 10V per line 3 phase, 3 wire + ground 208/220 VAC (operating range VAC) 380/400 VAC (operating range VAC) 440/480 VAC (operating range VAC) Hz >0.9 typical ½ cycle ride-though on all three phase 3 cycle ride through on single phase; missing phase shutdown 0.2% of full scale voltage 0.002% of full scale voltage < 2 Vpp measured across a 1µF capacitor at the end of a 1.8m (6ft) line at full load. 87% typical at nominal line and max load ±0.05% of set point after 30 minute warm-up and over 8 hours at fixed line, load and temperature, typical 0.02%/ C of maximum output voltage rating for voltage set point, typical 0.03%/ C of maximum output current rating for current set point, typical 0 to 50º C -25º C to 65º C Relative humidity up to 95% non-condensing, 0º C 50º C Operating full power available up to 5,000 ft. (~1,500 m), derate 10% of full power for every 1,000 feet higher; non-operating to 40,000 ft. (~12,000 m) Front and side air inlet, rear exhaust. Temperature controlled, variable speed fans. Units may be stacked without spacing.

4 600V PV simulator specifications, continued Regulatory Certified to UL/CSA and IEC/EN by a NRTL, CE Compliant, Semi- F47 Compliant. LVD Categories: Installation Category II: Pollution Degree 2; Class II Equipment: for Indoor Use Only. EMC Directive EN 61326:1998 Accessories Physical K : 3U Rack Slides : Front panel dust filter - field installation kit Width in (48.3 cm) Depth in (64.7 cm) Height 5.25 in (13.3 cm) Weight 40 lbs (18 kg) (5kW) 60 lbs (27 kg) (10kW) 80 lbs (36 kg) (15kW)

5 Software Control Screens The software provided with the TerraSAS is both powerful and easy to use. It can simultaneously show the dynamic irradiance profile being executed (graph on left) and the IV curve and position of the inverter tacking point (graph on right). IV curves and profiles are drag-anddrop capable onto the channel assignments on the far right. Profile execution can be controlled on the lower left. Complex and Real World simulation Experiment with various irradiance levels to observe the effects on the IV curve and analyze the inverter behavior under conditions that affect the overall system efficiency. Live inverter tracking This example was created by entering a 2-string array with 10 channels per string. This array is quite common for residential installations. This IV curve simulates a tree or chimney casting a shadow on three modules in the first string, reducing their irradiance to 20%, 50%, and 80% of their maximum. In this case, the MPP went from 4600W to 3718W, a 19.1% power loss caused by a 7.5% loss of irradiance. In the graph at the far right, PV panel bypass diodes were removed simulating the degradation of the string current and resultant power under the same conditions. This is useful to determine an inverter s reaction to panel fault conditions during partial shading of an array.

6 Company Overview and History AMETEK Programmable Power, formerly Elgar Electronics Corporation and California Instruments, is comprised of the Elgar, California Instruments, Sorensen, AMREL and Power Ten brands and is located and headquartered in San Diego, California, with over 450 employees. Within three facilities totaling more than 115,000 square feet (10,600 square meters), all equipment produced by the Programmable Power Division are designed and most are manufactured in our San Diego facilities. Elgar and California Instruments Brand AC Sources Since their beginning in the mid-sixties, Elgar and California Instrument s products have been used around the world in a variety of Test & Measurement applications. These programmable AC power sources are designed to meet a wide variety of commercial, industrial and military power requirements and have earned the company a reputation for quality and reliability in programmable power related products. Sorensen and Power Ten Brand Hi Power DC Sources Sorensen has been a leading manufacturer of high quality power supplies since 1943 and specializes in providing programmable DC power systems for a variety of OEM and test and measurement applications. Power Ten provides bulk power products into the Process Control and Test and Measurement markets. Engineered Solutions AMETEK Programmable Power s Solutions Business provides complete solutions to meet specific customer requirements. These solutions range OEM integration to turnkey integrated system solutions like Solar Array and Battery String Simulators for ground-based satellite testing. In fact, the Solutions business has been selected to supply Solar Array and Battery String Simulators on more satellite programs than any other company worldwide. The Solutions group is especially skilled at providing custom solutions using existing technology and previously developed integration solutions. This approach provides maximum functionality, short lead times and maximum value. Management Team AMETEK Programmable Power s management team is responsible for the company s operations and in key areas has dedicated focus activities, such as the Solutions Business. The nature of the Solutions business involves a high degree project management involvement with dedicated program management support reporting to the VP/Business Manager of Programmable Power Solutions. With regard to systems such as this, a Program Manager and Project Engineer and will be responsible for all technical and operational items from contract release to installation.

7 Manufacturing, Assembly and Acceptance Test AMETEK Programmable Power Solutions group has production facilities to handle the rapid growth of this segment of our business. The final integration and test area is 6000 ft 2 (557 m 2 ) and can easily accommodate the capacity required for this business. Other workspace will be made available to facilitate the efficient execution of any contract. A specially trained team from production operations performs production assembly and test of all Solutions products. Each system will undergo an extensive acceptance test. This acceptance test procedure will be provided. Documentation and Configuration Management Each TerraSAS system has a unique part number and its configuration is managed through AMETEK Programmable Power Solution s Change Control Board. All changes made to a TerraSAS system are rigorously documented. With each TerraSAS system comes a top-level drawing package, interconnect schematic and full system operations manual complete with the software interface control document. Quality System AMETEK s Quality Management System is certified to ISO 9001:2008 requirements. Additionally, the Quality Assurance Program also is in full compliance with the Code of Federal Regulations, Title 10, Part 50, Appendix B as applies to field service, spares, repair and technical support for equipment which was qualified for Class 1E applications in Nuclear Steam Power Electric Generating Power Stations located domestically and abroad. These core administrative programs coupled with stateof-the-art design, manufacturing technology, workmanship standards such as IPC 610 and 620, and other process controls yield a highly efficient Program that is tailored to meet evolving requirements.