The shift to higher voltages is helping reduce the cost of utility-scale photovoltaic systems. Higher-voltage systems make installations more energy efficient, require fewer components and less wiring, and are less labor intensive to build. Most new solar plants have voltages of 1500V on the DC side and many are moving towards 800V on the AC side.
ABB is adding a new molded case circuit breaker (MCCB) for higher-voltage solar power plants to its Tmax PV range and launching the solar industry’s first fully optimized two-pole DC (OTDC) switch-disconnector for 1500-volt utility-scale plants covering 315-630A IEC and 250-600A UL current range.
The new design offers both a size reduction and an increase in efficiency and performance to help manufacturers of PV combiner boxes, inverters, and energy storage systems adapt to the industry’s rapid adoption of 1500V DC solutions.
The two-pole 1500V DC concept helps manufacturers improve system efficiency, reducing switch losses by up to 35 percent. Measuring just 150mm wide and 122mm high across the current range, the OTDC range of 1500V DC switches is also up to 30 percent smaller than conventional solutions. The compact size of the new OTDC range makes it possible for manufacturers to reduce the size of combiner boxes and inverters.
ABB’s unique design makes it possible to operate up to two 1500V DC strings with just one switch. In addition to the standard connections, the OTDC’s modular design also makes it possible for ABB to fulfil the non-standard requests that come from the quickly changing solar market.
Molded case breaker
The breaker, designed to protect combiners, switchgear and inverters up to 1500V DC, is the latest addition to ABB’s complete range of protection solutions for utility-scale solar plants.
For 1500V DC installations with rated current up to 1200A UL and 1600A IEC, ABB’s product range now includes MCCBs and switch-disconnectors. The SACE Tmax PV range makes installation faster and reduces wiring costs for more advanced solar plants, helping utilities and engineers save time. The SACE Tmax PV offers design engineers, panel builders and inverter manufacturers a single–brand solution for photovoltaic systems installed anywhere in the world. All integrate readily with the electrical and mechanical accessories developed for the SACE Tmax T MCCB range.
For systems using string inverters, the SACE Tmax PV range now offers circuit breakers for up to 800V AC, the industry’s first to be type approved to UL 489 specifications and compliant with IEC 60947-2 Standard. ABB’s compact circuit breakers can break short circuit currents up to 32kA.
“We believe 800V AC will be a significant trend in large-scale solar plants,” said Marco Carminati, Global Product Specialist for ABB’s low-voltage breakers. “The response from partners indicates that it will be central to many developments in this field. We are now planning further innovations to support the shift to 800V so that solar plants have everything they need to optimize their power production.”
— Solar Builder magazine