Huawei Inverter Review

Huawei Inverter Global Team and Huawei Smart PV Solution

Huawei is a leading global Information Communications Technology solutions provider and the world’s largest telecommunication equipment manufacturer. It overtook Ericsson in 2012 and currently has 176,000 employees globally. Huawei exports its products and provides solutions to over 170 countries and regions. While not a listed company, Huawei has achieved annual sales revenue of USD 60.8 billion in 2015 with an increase of 37% over the previous year and ranked 228 of Fortune Global 500 the same year.

Huawei employs over 79,000 product and solution research and development (R&D) staff worldwide, comprising 45% of the company’s total workforce. It has set up 16 R&D centres and 36 joint innovation centres in countries including China, the United States, Canada, Germany, Ireland, Sweden, Turkey, India, Russia and Japan, and has invested around USD 9.2 billion on R&D in 2015. As a result of continuous growth in R&D investment, Huawei had filed 52,550 patent applications in China and 30,613 outside of China, with 50,377 granted by the end of 2015.

Huawei started development of the solar inverter business in 2009 and its solar inverter products belong to the Enterprise business group. The inverter team within Huawei currently has over 800 employees in R&D, with approximately 10% from foreign countries, and has more than 100 patents related to inverters. There are 6 R&D facilities under the Huawei Inverter Global Team:

Nuremberg, Germany – Architecture & design centre

Stockholm, Sweden – Algorithm & topology research centre

Shanghai, China – Product design centre

Shenzhen, China – Product engineering & manufacturing centre

Beijing and Chengdu, China – FusionSolar R&D centre

Santa Clara, United States – Innovative R&D centre

Since its formation in 2010, Huawei Inverter Global has grown rapidly. In 2014, it achieved a total shipment of 4 GW and sales orders of 5.5 GW, ranking number eight in the global market from IHS’ 2015 Q1 report. However, in 2015 orders are expected to reach 15 GW, with shipment totalling 10.5 GW. The inverters’ core components manufacturing and assembly site is based in the Songshan Lake factory in Dongguang, with a manufacturing capability of approximately 80,000 units per month, which is equivalent to approximately 2.8 GW.

Huawei is a major global manufacturer of telecommunications equipment and has recently entered the inverter manufacturing market, becoming one of the largest global players in the industry in a rapid period of time. Huawei has extensive in-house technical expertise for further research and development of inverters and recent growth has positioned Huawei as one of the world’s largest inverter manufacturers.

SUN2000 Series Inverter Technical Specifications

Huawei is relatively new to the solar inverter market but has over 20 years’ experience in the manufacturing of electronic components. Their main focus is on power supplies and controls systems which are the basis for the SUN2000 string inverter series.

The ethos of the SUN2000 string inverter series design is to minimise maintenance with high reliability and efficiency. The SUN2000 is a transformer-less grid-tied photovoltaic inverter which converts high voltage DC power into sine wave 3-phase grid-frequency AC. The absence of a transformer leads to higher efficiency, reductions in weight and size and a lower cost due to the reduced number of components.

The component parts of the SUN2000 series inverter system are located in a single aluminium cabinet with integral heat sink. The cabinet is IP65 rated for outdoor use which means the electronic components are protected against dust and water ingress which reduces the likelihood of damage to components. This is in line with industry standards.

The MPP voltage range of the inverters is wide meaning multiple system configurations are possible. Furthermore the separation between the maximum MPP voltage and maximum input voltage is wide enough for crystalline silicon module PV array systems. The power factor range of 0.8 leading to 0.8 lagging provides suitable control for typical grid connection requirements. Also total harmonic distortion is less than 3% which is considered acceptable.

The TA believes that the design of the inverter provides a safe and efficient means of converting DC power to AC. The inclusion of two or three model dependant MPPTs increases the efficiency of the inverter in multiple operational environments such as shading, different string output powers, different modules and varied tilt angles.

Quality Assurance Procedures

Quality assurance (QA) procedures are a requirement for any industry standard certification and Huawei has extensive experience in the manufacturing sector therefore has built up a wide range of QA procedures.

Huawei has a supply chain quality management committee established to ensure sub-supplier components are suitable for use in the inverter. There are two main departments in charge of this aspect:

Quality & Operation Management (QOM) Department.

Manufacturing Quality Management (MQM) Department.

The QOM department controls the daily quality management of the supply chain. The MQM department controls quality management of the manufacturing process with sub-departments including:

Quality audit.

Quality assurance.

Material quality.

Process quality.

Quality inspection.

Electronic Manufacturing Services (EMS) quality.

An end-to-end quality appraisal system is in place as verified by the TA’s factory inspection with regular inspections during the manufacturing process. Material and product reliability tests are conducted on both raw materials and manufactured products to ensure quality. All these data are fed into a quality information system which allows product traceability management and determine and solution of quality issues. The TA considers the overall quality assurance procedures to be well-defined and documented, allowing regular and close inspection of the entire manufacturing process.

Manufacturing Processes

Huawei’s global supply chain includes five key supply centres – one domestic supply centre (China) and four overseas (Hungary, Dubai, Mexico and Brazil). The centre in China also undertakes new product pilot testing and the core product manufacturing processes including raw materials, semi-finished product production, cabinet assembly, testing and delivery. The other supply centres potentially have the capability to manufacture inverters, although all are currently manufactured in the facility in China.

The manufacturing process for producing the Huawei SUN2000 inverters is explained in detail within this section.

Huawei’s core manufacturing centre is in operation at the Songshan Lake facility, which is located in Dongguan city within 50 km of Shenzhen Port and Guangzhou Port. The Songshan Lake facility has 24,000 employees for the production of all Huawei products within the confine of 1.4 k㎡. For the manufacturing of string inverters, two Original Equipment Manufacturers (OEMs), namely Foxconn and I-Brights are authorised by Huawei for providing Electronic Manufacturing Services (EMS) in 2014 and 2015 respectively. Details of these facilities are provided in Table 6-1.

Table 6 - 1: Manufacturing Facility Details

Representatives of SgurrEnergy conducted an inspection of Huawei’s manufacturing facility located in Shenzhen, China on 15 May 2014 and 6 January 2016 respectively. The inspection included a review of:

Long-term environmental testing of components and inverters.

Research and Development laboratory.

Inverter production line.

Meeting with after-sales personnel.

Meeting with manufacturing process engineers.

It is noted the TA was unable to take photographic images of the manufacturing process due to Huawei’s confidentiality requirements. Images are provided from documentation provided by the Client.

The core string inverter manufacturing process includes pre-assembly, Printed Circuit Board (PCB) and unit assembly, testing and packing with further details provided in the following sub-sections.

A computerised Manufacturing Execution System (MES) with appliance of the Internet of Things (IOT) technology is applied across the manufacturing process, covering in-production tracking and warehouse management. The MES system adds assurance that all quality procedures are suitably controlled and traceable.

FR:Shine Magazine