Tabuchi Electric Inverter Quality & Reliability Overview February 2017 Copyright 2017 Tabuchi Electric Company of America Limited. 1
Tabuchi Corporate History & Philosophy Established in 1925, Tabuchi Electric has a long company history and has grown into a leading electronics manufacturer that is publicly listed on the Tokyo Stock Exchange. In 1995, Japan became one of the first countries to promote grid-tied solar photovoltaic systems. That year, Tabuchi utilized its accumulated manufacturing knowledge and power supply expertise to produce solar inverters. Sharp Electronics was one of the first OEM customers to sell Tabuchi-manufactured inverters for their Sunvista inverter line. Tabuchi has produced nearly 1 million solar inverters since 1995, making it one of the world s oldest manufacturers of grid-tied inverters. Through a corporate philosophy rooted in best-in-class quality and a commitment to provide total customer satisfaction, Tabuchi has become a global leader in solar inverter manufacturing. Field Testing Over the past two decades, Tabuchi has performed a wide variety of field-testing to ensure product reliability and compatibility with all leading solar technologies and manufacturers. To date, tests have been conducted on 37 different types of solar PV modules from 26 different manufacturers. To facilitate testing, Tabuchi installed its own 600kW PV system for use as an evaluation test facility. In addition to the Tabuchi testing facilities in Japan, Tabuchi also monitors test sites for production in North America and Southeast Asia. 500kW PV System used in testing Combined Module Testing This enables Tabuchi to confirm the ability of its products to perform in a variety of climates from the humid tropics to extreme cold. One specific test site in Miyakojima, Japan was designed to evaluate the performance of Tabuchi products under harsh weather conditions. Located in Southeastern Japan, the site has average annual rain fall of close to 80 inches with average humidity of 79% and average temperature of 74 degrees. Testing has been conducted continuously at this site since 2004. MPPT & Multi-string Tracking A core advantage of Tabuchi s inverters is our multiple MPPT (Maximum Power Point Tracking) strings. Tabuchi is continually Copyright 2017 Tabuchi Electric Company of America Limited. 2
optimizing its MPPT functionality and multistring technology. To do this Tabuchi tests the performance of the maximum power point tracking function under a variety of conditions that impact the solar PV module (examples include: sand and snow accumulation, leaves, etc.). Sand Feed Test Simulated Environmental Testing Simulated environmental testing is an important and necessary function to ensure Tabuchi provides its customers with safe, reliable, and high performing products. Environmental Testing Tabuchi operates its own walk-in thermal chamber and PV power simulator to evaluate inverter performance under load and under a variety of weather conditions. Tabuchi simulates how the product functions under a variety of different PVpowered and grid-tied scenarios. Since Tabuchi has deployed over 1 million inverters, the company has collected a vast amount of monitoring data. The company is able to use this data to create a variety of real world simulations. For example, to better understand and improve inverter responsiveness, simulations are performed by rapidly fluctuating solar radiation under different temperature conditions. Snow Test Since June 2012, Tabuchi has verified the performance of its core multi-mppt function in Thailand. Thailand s hot and humid climate makes it a suitable testing ground. Five different types of PV technologies (Amorphous Si, multi-c Si, mono-c Si, Hetero junction Si, CIS) are tested at this site to better understand degradation patterns of photovoltaic modules. One advantage of having multi-mppt strings is the optimization of power production in the solar arrays despite differing rates of PV module degradation. Data from severe fluctuations in solar radiation Thermal Testing Tabuchi employs a stability test chamber evaluating the operation and durability of a particular inverter part or the entire inverter under various temperature and humidity conditions. The thermal-shock Copyright 2017 Tabuchi Electric Company of America Limited. 3
chamber is used to confirm the effect of thermal shock on the inverter, such as partial expansion, contraction, and/or deterioration. The walk-in chamber is so large that the test operator can directly enter the facility. Inverters and various inverter parts are being evaluated under several different test conditions. Dustproof Testing Thermal Testing Water-proof and Dust-proof Testing Knowing that dust and water are detrimental to the long-term health of the inverter, Tabuchi conducts extensive testing to ensure the long-term reliability of the inverter enclosure. To test the design of the enclosure, a water-proof tester is used to spray water at specific levels of water pressure. Similarly, to ensure that the enclosure can withstand damage from dust, a dust-proof tester is used to blow dust and talcum powder. EMC Testing Inverter emissions are tested in a shielded room without electromagnetic waves. Through this test, we confirm that our product meets emission standards. Ensuring High Production Quality All Tabuchi workers are tied together by the philosophy, We are committed to best-inclass quality in our products and total customer satisfaction. Tabuchi believes that the real reliability test is how our products perform for our customers. Product performance builds trust with our customers. As a company we do our best to ensure the highest standard of quality before our products reach our customers and we promise to continuously improve quality. During production, we inspect the inverter and its assembly at each step of the production process. Each inverter must pass safety, function, performance, and grid interconnection tests before being packaged and shipped to our customers. Waterproof Testing Board Inspection Tabuchi uses advanced automated optical inspection (AOI) to check the soldering and parts on each board. Copyright 2017 Tabuchi Electric Company of America Limited. 4
Safety Inspection This test confirms the safety of the inverter and ensures each product can withstand certain voltage and insulation resistance requirements. Board Inspection Device Performance Test We test the output performance and interconnection protection and communication functions. Automatic Inspection of the Finished Product Numerous tests related to grid interconnection and inverter output performance are performed by an automatic inspection machine. Inspection data is collected and analyzed for improvement of the production process. Performance Testing Rated Operation Aging The aging test ensures inverter performance at rated operation at 40ºC. Automatic Inspection Machine Factory Certifications Tabuchi s factories are ISO 9001 and ISO 14001 certified. ISO 9001 is a standard based on quality management principles including a strong customer focus and process focus for continual quality improvement. ISO 14001 is an environmental management standard. Aging Device Copyright 2017 Tabuchi Electric Company of America Limited. 5