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

- Contents - Photovoltaic energy system & business Photovoltaic power generation system Photovoltaic Inverter technology Photovoltaic Inverter of HHI Application of HHI Solar Energy System

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

< Block Diagram for Grid-connected Photovoltaic energy system > 2. Photovoltaic power generation system (1) Composition of Photovoltaic Energy System Data Transmission PV Array PCS Monitoring System Grid Load < 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.

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

Inverter (Grid-connected) 2. Photovoltaic power generation system (3) Concept of Solar Energy System for house use 1) Grid-connected system DC250∼850V AC/220V PV Array Grid Inverter (Grid-connected) 2) Stand-alone system AC PV Array Inverter Battery

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

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 High efficiency Low cost High reliability for DC current input

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 (250Vdc ~ 850Vdc) - 200Wp Solar module(6 inch Cell : 54 ea) → DC Voltage 26Vdc∼ 27Vdc Serial & parallel connection of module → Advanced capacity, voltage - 3kW PCS input voltage range : 250Vdc ~ 600Vdc 200W × 15ea serial connection → very useful to household system 2) Cooling Method & Protection Degree - 3kW 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. (3kW PCS : IP54) 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

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 ηeuro5%Pn + 0.06 x ηeuro10%Pn + 0.13 x ηeuro20%Pn + 0.1 x ηeuro30%Pn + 0.48 x ηeuro50%Pn + 0.2 x ηeuro100%Pn

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 (IncCond) ◈ Change of the solar module output characteristic (Temperature and solar radiation quantity)

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

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.

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 : 70MW → 150MW (2009) - Expansion in cell production line : 60MW → 330MW (2009) - Large scale power plant (MW) & System business for 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(3kW) to large capacity(250kW) - Series - Additional models are under development. (10kW, 30kW, 200kW, 500kW, 1MW) - Continuous development and version up for World No.1 Brand - Perfect product by making a verification test in actual field area. (HHI Solar Park : 500kW) - Package with our solar module and supply for large scale power plant construction (100kW, 250kW, 500kW, 1MW)

4. Photovoltaic Inverter of HHI (2) Photovoltaic Inverter model list of HHI 1) 3KW PCS (Transformerless type) - Supply for house in Korea - Protection degree : IP54 (Outdoor) - 1st PCS certificate in Korea (EMI/EMC) 2) 10KW PCS (Transformerless type) - Supply for commercial building - Simple & light weight (Project with national agency) 3) 12.5KW PCS (Built in transformer) - Supply for commercial building, Small size of power plant - Small size, Applicable to outdoor with option (IP43) 4) 50/100KW PCS (Built in transformer) - Small & Middle capacity (50KW, 100KW, 200KW System) - Launched in Korea (2009. 5) / CE Certificate schedule (2009. 8) 5) 250KW PCS (Built in transformer) - Supply for large capacity System - Under site test at our solar park in Korea (500KW ) - Will be launched (2009. 6) 6) 500KW/1MW PCS (Under Development) - Supply for very large capacity System - Development(2010. 6), Launch (2010. 12)

1) Low Price 2) High Efficiency 3) Reliability 4. Photovoltaic Inverter of HHI (3) HHI Strategy for PV Inverter - Various products from small capacity(3kW) to large capacity(250kW) – 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-003SL HPC-012HT HPC-050HT HPC-100HT HPC-250HT Product Rated Capacity(kW) 3kW 12.5kW 50kW 100kW 250kW Development State Launched (2007) (2008) Launched (2009) Design Concept Transformerless Built in transformer Target 1) Low Price 2) High Efficiency 3) Reliability 15/17

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

5. Application of HHI Solar Energy System Business for power generation 1. GESTAMP(Spain Fuente Alamo, 26MW) 2. Jang-heung, Solar power plant(104KW) 3. Hae-nam, Solar power plant(1.2MW) 4. Jeong-eup, Go-chang, Solar power plant(3.0MW) 17/17