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The multiple MPPT capability greatly increases the match between the solar array (PV panels), EES and utility grids. Image: KSTAR

The multiple MPPT capability greatly increases the match between the solar array (PV panels), EES and utility grids. Image: KSTAR

KSTAR has launched a new 1100V string grid-tied PV inverter with advanced features to support the adoption of high-performance bifacial modules and energy storage systems (ESS) for Commercial & Industrial (C&I) PV power plants designed to meet a wide-range of applications. The KSG-150UM/KSG-120CL series of inverters can be used in harsh environments with optimised performance harvesting.

Problem

Grid-tie inverters convert DC electrical power into AC power suitable for injecting into grids. The grid tie inverter (GTI) must match the phase of the grid and maintain the output voltage slightly higher than the grid voltage. As a result, a high-quality string grid-tie inverter, which has good performance and long-life working time in harsh environments and non-optimised settings is required. Advanced inverter functions are also needed to ensure the adoption of new technologies, such as bifacial modules and ESS are efficiently harvest for the lowest project LCOE (Levelised Cost of Electricity).

Solution

The 120KW-150KW KSG-150UM/KSG-120C string inverter has a 10/12 MPPT design for maximum energy harvest. The multiple MPPT capability greatly increases the match between the solar array (PV panels), ESS and utility grids. The MPPT converts a higher voltage DC output from solar panels down to the lower voltage needed to charge batteries. MPPTs are most effective under conditions such as winter seasons, low battery charge and long wire runs.

The KSG-150UM/KSG-120CL delivers a smart I-V Curve function for improving maintenance efficiency, which is used to check whether the state is good and whether there are shadowing effects, as well as accurate identification of problems, reducing time and cost for manual inspection. The smart I-V Curve function is a 100% online solution, improving remote monitoring capabilities.

The string inverter has a high precision RCD (Residual Current Device) protection circuit, constantly monitoring the current flowing in the live and neutral wires that operates quickly at a low earth leakage current, reducing safety issues. It can also be supplied with optional AFCI (Arc Fault Circuit Interrupters) and night SVG (Static Var Generator) functions. High precision RCD protection circuit helps to secure personal safety, while AFCI greatly reduces system risk, and the Night SVG function improves the grid support capacity. In addition, the latest string grid-tied PV Inverter is equipped with built-in PID (Potential Induced Degradation). Active arc protection can accurately detect any arc fault, and the inverter is shut down in 2.5 seconds to eliminate the arcing effects.  

Applications

Commercial and industrial PV power plants. The IP66 design can be used in extremely harsh environments, including temperatures of minus 25 degrees temperatures, through to floating solar plants. 

Platform

KSTAR developed an advanced online O&M platform Ksolar via Cloud Storage for the management of solar power plants. The collector can monitor the inverter, combiner box, DC distribution cabinet and box type transformer of PV power stations. In addition, a small meteorological monitor can be connected to monitor the environmental quantity of the power station. To ensure the operational uptime, the inverters are LED+Bluetooth APP/PLC Optional, as well as having a maximum DC/AC ratio of up to 1.5. Optional interfaces include RS485 / WiFi, GPRS, PLC.

Availability

August 2020 onwards.

Tags: shenzhen kstar science and technology, smart string inverter, solar-plus-storage, pv power plants, commercial and industrial solar

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