As the number of photovoltaic power-generation systems continue to increase, the requirements for photovoltaic inverters are evolving as well. Conventional electrical characteristics such as over-voltage, over-frequency, anti- islanding intended to verify the inverter’s ability to tolerate power grid fluctuation are changing to meet varying requirements of the modern grid. In addition, the introduction of new requirements for low voltage ride through, high voltage crossing, and reactive power injection mean the inverter must be able to provide appropriate compensation when these grid conditions occur.
To aid in the development and testing of the photovoltaic inverters, you can use powerful bi-directional AC power sources to simulate different power-grid conditions. To perform the required tests, the AC power sources or grid simulators must have a wide output voltage range or multiple output voltage ranges to accommodate the output voltages of different photovoltaic inverters.
Photovoltaic inverters can have output voltages of up to 800 VAC L-L (461 VAC L-N) and when testing high line conditions, the power source may have to output more than 1100 VAC L-L (635 VAC L-N).
When equipped with one of several different high voltage options, AMETEK Programmable Power’s RS Series AC power source can supply the necessary voltages. These options give the RS Series an additional voltage range with built-in hardware that eliminates the need for additional transformers to step up voltages to simulate the power grid. With this option, the RS Series can supply up to 650 VAC L-N (XV650).
HV and XV Options
The XV and HV high voltage options give the RS Series use internal autotransformers that step the voltage up to the desired level. There are several different options available, depending on the desired maximum output voltage, including:
- HV - 400 VAC L-N, 75 A
- XV500 - 500 VAC L-N, 60 A
- XV600 - 600 VAC L-N, 50 A
- XV650 - 650 VAC L-N, 46.2 A
With the XV650 option, an RS Series power source can supply up to 1,125 VAC L-L.
HVC and XVC Options
The HVC and XVC options are similar to the HV and XV options, but provide constant power output down to 80% of the maximum output voltage. At 80% of the maximum output voltage, an RS series power source can actually supply 125% of the maximum current supplied by an RS Series power source with an HV or XV high voltage option. See the figure below.
For example, an RS Series power source with the XV650 option has a maximum current output of 46A at 650 VAC. At 80% of maximum, or 520 VAC, the maximum available output current is still just 46A. With the XVC650 option, however, the RS Series power source can supply up to 57 A. The HVC and XVC options include:
- HVC - 400 VAC L-N, 93.8 A
- XVC500 - 500 VAC L-N, 75 A
- XVC600 - 600 VAC L-N, 62.5 A
- XVC650 - 650 VAC L-N, 57.7 A
Field Installation and Custom Ranges
The HV, XV, HVC, and XVC options can all be installed in the field. Please contact AMETEK Programmable Power to evaluate your upgrade options. AMETEK Programmable Power can also supply custom high-voltage voltages ranges. To inquire about a custom voltage range that is not listed, please contact us at firstname.lastname@example.org.
For information on the RS Series AC/DC power sources or the high voltage options, contact AMETEK Programmable Power. You can send an e-mail to email@example.com or phone 800-733-5427.