Module-Level Power Electronics Platforms: Page 3 of 4

Enphase Energy

Raghu Belur and former Cisco colleague Martin Fornage launched Enphase Energy in 2006 with the vision of creating not only a modern microinverter system that pushed power conversion and optimization into the array at the module level, but also a platform that enabled what was at the time an unprecedented level of system monitoring granularity. Both Belur and Fornage are still actively involved at Enphase, serving in the roles of vice president of products and strategic initiatives and chief technology officer, respectively. Enphase completed its IPO in 2012 and trades on the NASDAQ exchange with stock symbol ENPH. While Enphase has faced challenges in terms of its share price and profitability, it has clearly had the biggest impact of any microinverter system company on the development and advancement of the product class.

In early 2017, Enphase Energy began shipping its next-generation integrated solar, storage and energy management offering, the Enphase Home Energy Solution with IQ. The system features the company’s sixth-generation Enphase IQ Microinverter. The Enphase IQ 6+ Micro supports 60- and 72-cell modules up to 400 Wdc, and the Enphase IQ 6 Micro is compatible with modules up to 330 Wdc. The IQ 6+ model has a maximum input voltage of 62 Vdc and an MPP tracking range of 27 V–45 V. The IQ 6 model has a maximum input voltage of 48 Vdc and an MPP tracking range of 27 V–37 V. At 240 Vac the IQ 6 supports 20 A ac branch circuits of 16 modules, and the IQ 6+ supports 20 A ac branch circuits of 13 modules. The new microinverter design includes a double-insulated noncorroding polymeric enclosure. Enphase IQ 6 microinverters comply with fixed power factor, voltage and frequency ride-through requirements, and meet requirements for distributed solar on utility networks, including Rule 21 in California and Hawaiian Electric Company Rule 14H. Enphase IQ microinverters carry a warranty of 25 years. The C250 model, developed for 480 V 3-phase systems with 72-cell modules, rounds out Enphase’s microinverter lineup.

From the start, Enphase has had a system-level engineering approach. In February 2017, it added an energy storage component to its system with the availability of its AC Battery in the US. The AC Battery, a scalable modular energy storage system, is a component of Enphase’s Home Energy System, which includes the company’s IQ microinverters, Envoy networking hub and gateway, and module-level Enlighten monitoring software. The Enphase AC Battery uses lithium iron phosphate chemistry from Eliiy Power. The cells provide 1.2 kWh of capacity at a nominal voltage of 25.6 Vdc. The AC Battery can discharge to 100% of rated capacity and has a round-trip cell efficiency specification of 96%. Weighing only 55 pounds, the AC Battery is designed for single-person installation and interconnection with standard household wiring. Its enclosure is NEMA 2 rated for indoor installation in an unoccupied space. The AC Battery carries a 10-year or 7,300-cycle warranty for greater than 80% of its initial rated capacity.

In addition to offering integrated energy storage solutions, Enphase will add new ac module products in 2017, including some produced in partnerships with LG and Jinko Solar. Premiered in July at Intersolar North America in San Francisco, LG’s 60-cell 330 Wdc NeON 2 ACe model integrates Enphase’s IQ 6+ microinverter for ac module applications. This version, built on the IQ microinverter, includes an inverter-to-module mounting bracket that ships in a collapsed position, permitting optimal shipping density. Once on the rooftop, installers lift up the microinverter to connect the trunk cable, which elevates the microinverter off the back of the module by 15 mm to allow sufficient airflow for cooling. LG’s NeON 2 ACe ac module has a continuous ac power rating of 280 W.
Enphase Energy / Petaluma, CA / 877.797.4743 / enphase.com

Magnum Energy

Magnum Energy, founded in 2006, designs and manufactures inverter-chargers for mobile, marine, off-grid and backup power applications, as well as producing PV charge controllers, component integration panels and system monitoring equipment. In 2014, Sensata Technologies acquired Magnum Energy. Headquartered in Attleboro, Massachusetts, and founded in 1916, today Sensata Technologies is a global provider of sensing, electrical protection, control and power management solutions with operations and business centers in 13 countries.

In 2016, Magnum announced the launch of its MicroGT 500 microinverter. Designed for integration with the company’s battery-based inverter-charger systems, as well as for use in grid-direct power export applications, the MicroGT 500 communicates with Magnum Energy battery-based inverters in ac-coupled mode to taper the charge based on temperature-compensated battery state-of-charge parameters.

Each dual-MPPT MicroGT 500 microinverter supports two PV modules. For the dc side, Magnum recommends a module STC power range of 180 W–310 W, but the inverter can accommodate modules of up to 365 W. The microinverter has a maximum input voltage of 55 Vdc and an MPP tracking range of 22 V–45 V. Its rated ac power output is 500 W. Each 20 A breaker supports ac branch circuits of up to seven microinverters (14 modules). The MicroGT 500 is NEC 690.12 compliant.

Magnum was the first manufacturer in the US to offer inverter-charger models with split-phase 120/240 Vac output. Its 24 Vdc and 48 Vdc nominal MS-PAE series inverter-chargers connect to the grid for ac battery charging, but do not export power to the utility grid without the integration of an ac-coupled string or microinverter system, such as its MicroGT 500 microinverter. Magnum Energy’s MagWeb GT communication unit provides an integrated dashboard of the MicroGT output and MS-PAE Inverter/Charger output, including the battery state of charge.
Magnum Energy / Everett, WA / 425.353.8833 / magnum-dimensions.com

Article Discussion

Related Articles