HYUNDAI Photovoltaic Inverter HYUNDAI HEAVY INDUSTRIES CO LTD

HYUNDAI Photovoltaic Inverter HYUNDAI HEAVY INDUSTRIES CO. , LTD Electro Electric Dept. 0/17

- Contents - 1. Photovoltaic energy system & business 2. Photovoltaic power generation system 3. Photovoltaic Inverter technology 4. Photovoltaic Inverter of HHI 5. Application of HHI Solar Energy System 1/17

1. Photovoltaic energy system & business (1) Value Chain for Photovoltaic Energy Poly Silicon Ingot/Wafer PV Cell Upstream ▪ Original material for Ingot 2/17 ▪ Silicon Melting ▪ Ingot Growing PV Module System Downstream ▪ Cell Production ▪ Module Production ▪ PV Array, PV Inverter, Battery, Support, Monitoring system, Installation

2. Photovoltaic power generation system (1) Composition of Photovoltaic Energy System Grid Load PV Array PCS Monitoring System Data Transmission < Block Diagram for Grid-connected Photovoltaic energy system > ▪ PV Array (Solar Module Panel) : Modules are used suitably in series or parallel connection. ▪ Peripheral components (BOS : Balance of System) : Support for module installation, Battery ▪ Power Conversion Device (PV Inverter) : PCS (Power Conditioning System) - PCS converts DC power generated in PV array to AC power. 3/17

2. Photovoltaic power generation system (2) Classification of Photovoltaic Energy System 1) Grid-connected System - The output of solar system is connected to main grid. - The shortage power is supplied from grid, the surplus power is re-supplied to grid. - Used for House, Building, Grid Reinforcement, Power Generation (MW Level) 2) Stand-alone System - Isolated from grid, Used to small capacity load in rural area without grid. - The power storage device (ex. the battery) is necessary when the generation is impossible. 3) Hybrid System - System which is combined with other generation system such as wind turbine generator, diesel generator etc. - Used in the island, isolated area, military equipment without commercial power 4/17

2. Photovoltaic power generation system (3) Concept of Solar Energy System for house 1) Grid-connected system PV Array Inverter (Grid-connected) DC 250∼ 850 V Grid AC/220 V 2) Stand-alone system PV Array Inverter AC Battery 5/17

3. Photovoltaic Inverter technology (1) Considerable feature for photovoltaic inverter 1) Change of the environmental condition - Solar radiation, Surface temperature of PV array, Shadow by obstacle or cloud → Environmental condition is changed frequently and rapidly. 2) Response for the environmental change - Tracking for most efficient point of PV array : Maximum Power Point Tracking (MPPT) 3) Synchronized operation with grid - Synchronized operation with grid voltage 4) Protective function - Inverter protection from grid fault condition - Grid protection from the fault condition of a solar energy system 6/17

3. Photovoltaic Inverter technology (2) Design topology for PCS Power circuit Design Topology Circuit Diagram Feature Low frequency Transformer Type § § Easy isolation & Simple circuit Low efficiency for small capacity Big size and heavy weight Method applied for large capacity models High frequency Link type § § § Small size & light weight Complex circuit for isolation High cost Efficient improvement is difficult. Not applicable for large capacity models Transformerless Type § § § Small size & light weight High efficiency Low cost High reliability for DC current input Not applicable for large capacity models 7/17

3. Photovoltaic Inverter technology (3) Requirements for Photovoltaic Inverter 1) DC input voltage range - Wide range of input voltage → Various kind of serial connection for solar module (250 Vdc ~ 850 Vdc) - 200 Wp Solar module(6 inch Cell : 54 ea) → DC Voltage 26 Vdc∼ 27 Vdc Serial & parallel connection of module → Advanced capacity, voltage - 3 k. W PCS input voltage range : 250 Vdc ~ 600 Vdc 200 W × 15 ea serial connection → very useful to household system 2) Cooling Method & Protection Degree - 3 k. W PCS : Natural cooling (without Fan) → No Noise - When PCS is independently established to outdoor, it is necessary to have high protection degree for the dust and water. (3 k. W PCS : IP 54) 3) Detecting for DC current input - DC current input with the AC grid output can lead to the abnormal condition or damage to PCS. - Within 1%, detecting time : within 0. 5 sec 8/17

3. Photovoltaic Inverter technology 4) Protection for grid abnormal connection - PCS protection for the abnormal or breakdown condition to minimize the range of accident. - Detecting for Over voltage, Under voltage, Over frequency, Low frequency 5) Noise reduction - very important to indoor type - Switching frequency → over audio frequency - Without fan → No Noise - Air Cooling : Fan speed control according to the load 6) European Efficiency - Considering for the operation from low load condition to full load condition - Efficiency with 5%, 10%, 20%, 30%, 50%, 100% load condition. → Total power efficiency is produced. - European Efficiency ηeuro = 0. 03 x ηeuro 5%Pn + 0. 06 x ηeuro 10%Pn + 0. 13 x ηeuro 20%Pn + 0. 1 x ηeuro 30%Pn + 0. 48 x ηeuro 50%Pn + 0. 2 x ηeuro 100%Pn 9/17

3. Photovoltaic Inverter technology 7) MPPT (Maximum Power Point Tracking) control - Because the output characteristic of PV array changes according to solar radiation and surface temperature, maximum output power point changes. (solar radiation increases → output power increases, temperature increases → output power decreases) - Watching and following function to operate at Maximum power point. - Algorithm : Perturbation and Observation (P&O), Incremental Conductance (Inc. Cond) ◈ Change of the solar module output characteristic (Temperature and solar radiation quantity) 10/17

3. Photovoltaic Inverter technology 8) Anti-Islanding Function - Islanding Operation : PCS continue to operate under power failure or grid accident. - Safety Problem : Electric Shock - It is important to synchronize between grid and PCS voltage. - When the power failure or grid accident is occurred, PCS must detect the fault condition and stop its operation. - Detecting for islanding operation : Passive & Active Method a) Passive Method ▪ Detecting from grid parameter value (Voltage, Frequency) ▪ Power mismatch → voltage & frequency variation → Islanding condition b) Active Method ▪ Detecting from response characteristic for the intended grid fluctuation. ▪ PCS output voltage fluctuation, frequency transfer, reactive power addition, etc ▪ Very useful method but very complex ▪ Unstable : Non-detection zone 11/17

3. Photovoltaic Inverter technology 9) Standby power - Minimum standby power → Higher efficiency 10) Weight - Size & Weight is very important. (Small size & Light weight) 11) Communication & Monitoring system - Instantaneous power and accumulated power, Monitoring system for watching whether the system operates correctly. - Communication condition for using a PC (Personal Computer) network. 12/17

4. Photovoltaic Inverter of HHI (1) Photovoltaic power generation system business of HHI 1) Photovoltaic energy business - Poly Silicon, cell, module, PCS, system : Total solution for solar energy - Large scale investment - Expansion in module production line : 70 MW → 150 MW (2009) - Expansion in cell production line : 60 MW → 330 MW (2009) - Large scale power plant (MW) & System business foreign countries 2) Photovoltaic Inverter business - Design experience and know-how in the Industrial inverter, UPS, Electric Vehicle, Electric components for rapid electric railway → Basic technology of PCS - Various products from small capacity(3 k. W) to large capacity(250 k. W) - Series - Additional models are under development. (10 k. W, 30 k. W, 200 k. W, 500 k. W, 1 MW) - Continuous development and version up for World No. 1 Brand - Perfect product by making a verification test in actual field area. (HHI Solar Park : 500 k. W) - Package with our solar module and supply for large scale power plant construction (100 k. W, 250 k. W, 500 k. W, 1 MW) 13/17

4. Photovoltaic Inverter of HHI (2) Photovoltaic Inverter model list of HHI 1) 3 KW PCS (Transformerless type) - Supply for house in Korea - Protection degree : IP 54 (Outdoor) - 1 st PCS certificate in Korea (EMI/EMC) 2) 10 KW PCS (Transformerless type) - Supply for commercial building - Simple & light weight (Project with national agency) 3) 12. 5 KW PCS (Built in transformer) - Supply for commercial building, Small size of power plant - Small size, Applicable to outdoor with option (IP 43) 4) 50/100 KW PCS (Built in transformer) - Small & Middle capacity (50 KW, 100 KW, 200 KW System) - Launched in Korea (2009. 5) / CE Certificate schedule (2009. 8) 5) 250 KW PCS (Built in transformer) - Supply for large capacity System - Under site test at our solar park in Korea (500 KW ) - Will be launched (2009. 6) 6) 500 KW/1 MW PCS (Under Development) - Supply for very large capacity System - Development(2010. 6), Launch (2010. 12) 14/17

4. Photovoltaic Inverter of HHI (3) HHI Strategy for PV Inverter - Various products from small capacity(3 k. W) to large capacity(250 k. W) – Line-up and Series - Continuous development and version up for World No. 1 Brand - Perfect product by making a verification test in actual field area (Solar Park at Eum-Seong, Korea) - Package with our solar module and supply for power plant construction (4) Development model of HHI PV Inverter Model HPC-003 SL HPC-012 HT HPC-050 HT HPC-100 HT HPC-250 HT Rated Capacity(k. W) 3 k. W 12. 5 k. W 50 k. W 100 k. W 250 k. W Development State Launched (2007) Launched (2008) Design Concept Transformerless Product Target Built in transformer 1) Low Price 15/17 Launched (2009) 2) High Efficiency 3) Reliability

5. Application of HHI Solar Energy System v Business for Power Generation ASAN Medical Center (Seoul, Korea) - 147 k. W System 16/17

5. Application of HHI Solar Energy System v Business for power generation 1. GESTAMP(Spain Fuente Alamo, 26 MW) 3. Hae-nam, Solar power plant(1. 2 MW) plant(3. 0 MW) 17/17 2. Jang-heung, Solar power plant(104 KW) 4. Jeong-eup, Go-chang, Solar power