China Shenzhen First Tech Co., Ltd. Company Cases

Timeframe: April 2024 - Ongoing Location: Surat, Gujarat, India (Industrial Zone) End-User: Patel Textile Workshop (Family-owned business with 8 power looms) Operational Challenges     Grid Instability: 4-8 hour daily outages during monsoon season (June-Sept) Voltage Fluctuations: 160-260V swings damaging motor controllers Diesel Dependency: 15L/day generator consumption (₹110/L) Critical Load: 3.8kW essential machinery (computerized looms + design stations) Technical Implementation     Selected Model: EM3500-24L (3.5kW) → Matches peak load (3.8kW) with 7,000VA surge capability Key Feature Utilization: • 90-280V input range handles grid fluctuations • 20ms transfer time prevents loom shutdowns • PV-only battery activation enables off-grid operation Monsoon Season Performance (July 2024) Parameter Specification Field Result Voltage Stability 220V±5% 223.4V±1.8% during grid swings Outage Response 20ms transfer 18.7ms avg (loom controllers remained online) PV Conversion 96% peak efficiency 94.2% @ 3.2kW load Thermal Management -10°C~50°C operating 46°C during 38°C ambient Humidity Tolerance 5-95% RH 89% RH without condensation issues   Economic Impact # Cost Savings (INR) diesel_cost = 15L/day * ₹110 * 120 outage_days grid_penalty = ₹8/kWh * 18kWh/day * 120 days print(f"Annual Savings: ₹{diesel_cost + grid_penalty:,.0f}") # Output: Annual Savings: ₹324,600       ROI Period: 14 months (System cost: ₹378,500) Productivity Gain: 22% increased output (eliminated loom reboots) Real-World Operation Scenario During July 15 grid collapse (9 hours):   Load Profile: • Power Looms: 2.8kW • Design Station: 0.6kW   PV maintained battery at 27V float charge Inverter delivered 3.4kW continuous: Touchscreen displayed: "Source: Solar+Battery → Runtime: 11h 42m" Technical Validation Motor Protection: Crest factor 3:1 handled loom startup surges Battery Synergy: RS485 communication maintained 24V±0.5V Environmental Compliance: Operated at 47°C workshop temp (within 50°C limit) Survived 95% humidity monsoon with IP22 enclosure Long-Term Reliability Metrics Component Stress Test Result Inverter 140% overload Shutdown in 4.8s (spec: 5s) Electronics 280V input (10min) Automatic voltage reduction Connectors 100A solar input

Time Period: March 2024 - Present Location: Alice Springs, Northern Territory, Australia (Latitude: 23.6980°S) End-User: The Patterson Family (Cattle Station Operators) Property: 50-hectare remote homestead with off-grid solar system Challenge The Pattersons' 200km² cattle station faces:       Extreme temperature swings (-5°C to 48°C annually) Unreliable diesel generator backup (AUD $1.80/L fuel costs) Existing lead-acid batteries failing after 18 months due to thermal stress Critical need for 24/7 power for water pumps and refrigeration Solution Deployment System Configuration: Parallel installation of two RPES-WM4 units (25.6V 200Ah each → 10.24kWh total) Wall-mounted in shaded equipment shed (650×384×142mm compact footprint) Touchscreen monitoring integrated with existing SCADA system Key Feature Utilization: -20°C discharge capability: Maintained water supply during July 2024 freeze (-3°C) 100A max discharge: Handled simultaneous pump startup surges (87A peak) 98% efficiency: Reduced solar panel requirements by 22% vs previous system Performance Validation (Aug 2024 Heatwave) Parameter Specification Field Data Ambient Temp Discharge: -20°C~60°C 52°C shed temperature Cycle Depth 80% DoD (per cycle life spec) Daily 78-82% DoD Discharge Rate Max 100A Sustained 92A during irrigation Energy Output 5.12kWh/unit 9.98kWh daily usable output Cycle Count >6000 cycles 428 cycles with 0.4% capacity loss Economic Impact Analysis # Cost Savings Calculation (AUD) diesel_cost = (8L/hr * AUD$1.80 * 6hr/day * 180 days) solar_loss = (22% reduced panel cost * AUD$0.55/W * 15,000W) print(f"Annual Savings: AUD${diesel_cost + solar_loss:,.0f}") # Output: Annual Savings: AUD$18,576   ROI Period: 3.2 years (System cost AUD$12,500 ÷ Annual savings) Hidden Value: Prevented AUD$40,000 livestock loss during 2024 drought (continuous water pumping) Real-World Operation Highlights During December 2024 bushfire crisis: Operated at 58°C ambient (within 60°C discharge limit) Touchscreen displayed: "Storage: 63% → Runtime: 9h 22m (at current load)" Enabled 14-hour continuous operation of fire pumps when grid failed Wall-mounted design survived 2024 dust storms (5-95% humidity compliance), while 48kg weight allowed installation without structural reinforcement. Longevity Verification Accelerated Testing: Simulated 10-year degradation at Alice Springs conditions → 83.7% capacity retention Warranty Alignment: Manufacturer's 10-year coverage matches local insolation patterns (2,300 kWh/m²/yr UV exposure) "The SMPCE features aren't marketing fluff – that 98% efficiency literally keeps our cattle alive during summer." - James Patterson, Station Manager Regional Suitability: Selected Australia for its alignment with: Extreme temperature tolerance requirements (-5°C to 48°C) World's highest residential solar penetration (30%+) Critical need for cyclone/bushfire backup power *This case demonstrates RPES-WM4's capability to deliver manufacturer-specified performance under Earth's most demanding climatic conditions while creating tangible economic value.*

1. Customer Background Amina Mohammed owns a 200m² family - run grocery store in Ikeja, Lagos, Nigeria. The store specializes in fresh produce (leafy greens, tomatoes) and dairy (yogurt, cheese), supported by: A 3kW walk - in cooler (critical for perishable goods). 1kW LED lighting + POS systems. A 5 - year - old solar + storage system: 6×300W polycrystalline PV panels, a 48V lead - acid battery bank (200Ah), and an outdated inverter (85% efficiency, frequent failures). Lagos’ energy challenges hit hard: Grid unreliability: 4–6 outages daily, lasting 2–4 hours. Cooler failures caused 300–300–500 in spoiled goods monthly. High diesel costs: A 5kVA generator ran 8 hours/day, costing ~$800/month in fuel. Inefficient solar: The old inverter wasted 15% of solar energy; degraded lead - acid batteries lost 30% capacity, reducing self - sufficiency. 2. Pain Points & Requirements Reliable Backup: The 3kW cooler + 1kW loads needed “zero - downtime” protection during outages (spoilage risk = 15% revenue loss). Cost Reduction: Slash diesel spend and maximize solar self - consumption. System Compatibility: Reuse the 48V lead - acid battery bank (avoid $1,500 replacement cost). Integrate 2×450W monocrystalline PV panels (new investment) with old 300W poly panels. Environmental Resilience: Lagos’ 35–40°C summers, high humidity (70–90%), dusty harmattan winds, and annual thunderstorms demanded rugged hardware. Safety & Compliance: Meet Nigerian Standards Organization (SONCAP) requirements and protect against lightning surges. 3. Inverter Selection: SP5KH After technical audits, the SP5KH model was chosen for its precise alignment with Lagos’ demands. Here’s how it solved each challenge: 4. Technical Fit: SP5KH’s Solutions (1) Efficiency & Cost Savings PV - to - AC Efficiency: 97.8% max efficiency (vs. old inverter’s 85%) reduced solar energy loss by 12.8%. Daily solar yield increased from 12kWh to 14.5kWh, cutting diesel runtime from 8h to 2h/day (saving $650/month on fuel). Battery - to - AC Efficiency: 97.0% max efficiency minimized discharge losses from the aging lead - acid bank. Battery runtime for backup increased by 20%, powering the cooler for 6 hours during outages (vs. 4 hours prior). (2) PV System Compatibility Dual MPPT Design: With 2 MPPT channels and an MPPT voltage range of 70V–540V, SP5KH optimized power from mixed panels: Old 300W poly panels (Vmp = 30V) on MPPT 1. New 450W mono panels (Vmp = 40V) on MPPT 2. Even during harmattan (low - light dust storms), MPPT dynamically adjusted, boosting solar self - consumption from 50% to 75%. High PV Input Capacity: 12,000W max PV input allowed future expansion (Amina plans 4 more 450W panels next year). (3) Battery Flexibility & Backup Reliability Dual Battery Support: SP5KH works with lithium - ion/lead - acid batteries. Reusing the 48V lead - acid bank saved $1,500, while retaining the option to add lithium - ion later. Backup Power & Transfer Speed: 5,000W nominal backup output matched the store’s 4.5kW critical load (cooler + lighting + POS).

1. Customer Background Mr. Smith owns a 5 - hectare family - run farm on the outskirts of Johannesburg, South Africa. The farm focuses on organic vegetable cultivation and small - scale dairy processing (with refrigerated storage for 500L of milk daily). For years, the farm faced challenges: Heavy reliance on diesel generators (costing ~$500/month in fuel, with frequent breakdowns). An aging grid - tied solar system (installed 8 years prior, featuring inefficient inverters and degraded lead - acid batteries). Unreliable local grid, with 3–5 outages weekly (each lasting 2–4 hours), risking spoiled dairy products and damaged crops due to interrupted irrigation. 2. Key Pain Points & Requirements Cost Reduction: High diesel costs and rising electricity tariffs made energy the farm’s second - largest expense. Reliable Backup Power: Critical loads (5kW refrigeration, 3kW irrigation pump) required “zero - downtime” protection during grid outages. System Compatibility: Reuse existing 48V lead - acid batteries (to avoid the cost of full system replacement). Integrate new high - efficiency PV modules (2×450W monocrystalline panels) with old polycrystalline panels (2×300W, installed in 2018). Environmental Resilience: Johannesburg has summer temperatures up to 42°C, dry and dusty conditions, and an altitude of 1,700m (with occasional thunderstorms in the rainy season). Safety & Compliance: Meet South African electrical standards (SABS) and protect against lightning surges (common in summer storms). 3. Inverter Selection: SP5KL After technical evaluation, the SP5KL model was selected for its perfect match with the farm’s needs. Here’s how it addressed each challenge: 4. Technical Fit: How SP5KL Solved Pain Points (1) Energy Efficiency & Cost Savings PV - to - AC Efficiency: With a maximum efficiency of 97.3% and a European efficiency of 96.8%, SP5KL minimized energy loss during solar power conversion. The old system’s inverter (with 85% efficiency) wasted 15% of solar energy; SP5KL reduced this loss by 12%, increasing the daily solar yield by 18%. Battery - to - AC Efficiency: A maximum efficiency of 94.3% reduced discharge losses from the aging lead - acid batteries. Combined with improved solar harvesting, the diesel generator runtime decreased from 10 hours/day to just 2 hours (only on extremely cloudy days), cutting fuel costs by 80% ($400/month savings). (2) PV System Compatibility Dual MPPT Design: Equipped with 2 MPPT channels and an MPPT voltage range of 70V–540V, SP5KL efficiently tracked power from the mixed PV array: Old polycrystalline panels (300W, Vmp = 30V) operated on MPPT 1. New monocrystalline panels (450W, Vmp = 40V) operated on MPPT 2. Even during Johannesburg’s winter (with low - light mornings), MPPT adjusted dynamically to extract maximum power, increasing solar self - consumption by 25%. High PV Input Capacity: The 10,000W maximum PV input power allowed the farm to expand its array (from 4kW to 8kW) without upgrading the inverter, future - proofing the system. (3) Battery Flexibility & Backup Reliability Dual Battery Support: SP5KL is compatible with both lithium - ion and lead - acid batteries. The farm reused its existing 48V lead - acid bank (saving $2,000 on battery replacement) while keeping the option to add lithium - ion batteries in the future. Backup Power & Transfer Speed: The 5,000W nominal backup output power matched the farm’s critical load (5kW refrigeration + 3kW pump, operated in shifts). With a transfer time of

Here is a comprehensive overview of the inverter lifecycle process from production to after-sales service, based on industry standards and manufacturing practices: 1. Production & Manufacturing Design & Planning: Technical specifications are finalized based on market requirements and regulatory standards (e.g., IEC, UL) 2 . Component Procurement: Sourcing critical parts (capacitors, IGBTs, PCBs) with strict quality control 2 11 . PCB Assembly: SMT (Surface Mount Technology): Automated placement of micro-components 1 . DIP (Dual In-line Package): Manual insertion of larger components. Module Assembly: Integration of power modules, control boards, and heat sinks 1 . Casing & Wiring: Installation of enclosures, cooling systems, and electrical connections 1 . 2. Quality Control & Testing In-process Checks: Real-time monitoring at assembly stages (e.g., solder quality, component alignment) 1 11 . Functional Testing: Electrical Safety: Insulation resistance, dielectric strength (e.g., 1,500V startup voltage) 11 . Performance: Efficiency, output waveform, harmonic distortion. Reliability Testing: Environmental Simulation: Temperature cycling (-30°C to 60°C), humidity, and vibration tests 11 25 . Aging Test: 48-hour stress testing under extreme conditions. Safety Certification: Compliance with VDE, TÜV Rheinland, or UL standards. 3. Packaging & Logistics Final Inspection: Cosmetic review and electrical retesting 1 . Packaging: Anti-static wrapping, protective padding, and IP65-rated boxing for moisture resistance 11 . Labeling: Barcodes for traceability and compliance markings (CE, RoHS). 4. Installation & Commissioning Site Preparation: Ensuring ventilation, shade avoidance, and clearance (≥30 cm around inverter) 22 . Electrical Connections: DC Side: PV string wiring with MC4 connectors; polarity checks. AC Side: Grid connection via circuit breakers; grounding verification. Grid Synchronization: Testing grid compatibility (voltage/frequency ranges). Commissioning: Activating via monitoring apps (e.g., Solar Go). 5. Operation & Maintenance Routine Checks: Physical: Dust removal from fans, cable integrity, and thermal inspection (using IR cameras) 25 . Electrical: Monitoring leakage current, insulation resistance, and efficiency drops 34 . Predictive Maintenance: Replacing cooling fans every 3–5 years 25 . Exercising DC switches annually to prevent contact degradation. Fault Handling: Common issues: Grid overvoltage, insulation faults, or communication errors 34 . Solutions: Adjusting grid settings, rewiring damaged cables, or firmware updates 34 . 6. After-Sales Service Warranty Support: 5–10 years coverage for manufacturing defects; onsite technician dispatch 25 . Remote Diagnostics: Monitoring platforms (e.g., Growatt, SMA) for real-time alerts 34 . Spare Parts Management: Stocking critical components (fans, PCBs) for rapid replacement. End-of-Life: Recycling programs for electronic waste; carbon footprint offset analysis (e.g., SMA’s 1.4-year CO2 payback).

An inverter is a power conversion device that converts 12V or 24V direct current (DC) into 230V, 50Hz alternating current (AC) or other types of AC power. The output AC power can be used by various types of equipment, meeting the AC power needs of users in mobile power supply locations or off-grid areas to the greatest extent. Also known as an inverter power supply, this device enables the use of DC power sources (like batteries, switching power supplies, fuel cells, etc.) to be converted into AC power, providing stable and reliable electricity for appliances such as laptops, mobile phones, handheld PCs, digital cameras, and various instruments. Inverters can also be used in conjunction with generators, effectively saving fuel and reducing noise. In the fields of wind and solar energy, inverters are indispensable. Small inverters can utilize the power from automobiles, ships, or portable power supply devices to provide AC power in the field. Inverters have a wide range of applications. They can be used in various means of transport, such as automobiles, ships of all kinds, and aircraft. In solar and wind power generation, inverters play an indispensable role. Working Principle of Inverter An inverter is a DC-to-AC (Direct Current to Alternating Current) transformer. As the name suggests, it transforms voltage in reverse. Essentially, it performs a voltage inversion process opposite to that of an adapter (Adapter). While an Adapter converts AC voltage from the mains grid into a stable 12V DC output, the Inverter converts the 12V DC voltage from the Adapter into high-frequency, high-voltage AC. Modern inverters typically employ PWM (Pulse Width Modulation) technology to achieve high-power, high-efficiency AC inversion output. Main Components 1. Input Interface Section The input section typically processes three signals: 12V DC Input Voltage: Supplied by the DC output from an Adapter. Operation Control Voltage: Provided by the control chip on the mainboard, valued at 0V or 3V. When control voltage = 0V, the inverter stops working. When control voltage = 3V, the inverter operates normally. Panel Current Control Signal: Generated by the mainboard, with a voltage range of 0–5V. This signal is fed back to the PWM controller's feedback terminal. Lower current control signal values result in higher output current from the inverter. 2. Voltage Startup Circuit When the operation control voltage is at a high level (3V), this circuit outputs high voltage to ignite the backlight lamp of the Panel. 3. PWM Controller Comprises the following functional blocks: Internal reference voltage Error amplifier Oscillator and PWM generator Overvoltage protection (OVP) Undervoltage protection (UVP) Short-circuit protection (SCP) Output transistors 4. DC Conversion Circuit Consists of MOS switching transistors and an energy-storage inductor, forming a voltage conversion circuit. Input pulses are amplified by a push-pull amplifier to drive the MOS transistors. Switching actions of MOS transistors charge/discharge the inductor, converting DC into AC voltage. 5. LC Oscillation and Output Circuit Generates 1500V to ignite the lamp during startup. Reduces voltage to 800V after lamp ignition for stable operation. 6. Output Voltage Feedback When the load operates, the feedback circuit samples the output voltage to stabilize the inverter's voltage output. Multi-Output Design for Large-Screen Applications Inverters typically feature multiple input channels and a single high-voltage output. For LCD panels with multiple backlight lamps in large-screen TVs, manufacturers generally use either: Multiple inverter boards, or Separate inverters for independent outputs.   Safety Certification Requirements Since inverters generate high voltages during operation, materials and components (e.g., inverter transformers, PCBs, and output sockets) must comply with safety and fire-resistance standards. Key safety certifications include: 1) Temperature Rise Test Verifies that during normal operation or under single-fault conditions, temperatures of internal components (transformers, PCBs, etc.) will not: Endanger personal safety, or Disrupt adjacent device functionality. 2) Fire Resistance Requirements Ensures high-temperature components (transformers, PCBs, etc.) possess adequate fire-resistance ratings to: Prevent self-ignition, and Slow/block flame propagation from external fires. 3) Electric Strength Test Evaluates whether high-voltage output (generated during operation) could compromise insulation of the inverter transformer, causing high-voltage leakage to low-voltage input circuits and endangering users. 4) Current-Limiting Circuit Test Critical safety measure since users may touch the LCD surface. If the screen cracks, users risk exposure to inverter-generated high voltage. When voltage reduction isn’t feasible, current-limiting circuits restrict output current to protect users. Note: If inverters from different manufacturers are used in a product, additional current-limiting circuit tests are mandatory.

Delivered Product: 30kW/100kWh EnerArk Outdoor Battery Energy Storage Integrated Cabinet   Application: Deployed at an industrial park in Longgang, Shenzhen, this energy storage system serves as a "Storage + EV Charging Station" demonstration project, achieving three core objectives:   Peak shaving & valley filling through intelligent charge/discharge cycles Energy transfer for time-of-use (TOU) tariff optimization Comprehensive electricity cost reduction    

Delivered Products: 3 units of 60kW/147.84kWh outdoor battery energy storage all-in-one systems     Application Case: Shenzhen First Tech Co., Ltd. has delivered 3 sets of 60 kW /147.84kWh integrated solar-storage solutions to a South African factory, enabling triple benefits: Uninterrupted power supply Green energy utilization Cost efficiency optimization   Operational Modes: Grid-connected Scenario (Mains power available): Outdoor battery energy storage cabinets operate in grid-tied mode Priority consumption of photovoltaic (PV) generation Peak shaving & valley filling via energy storage Emergency backup readiness   Islanded Scenario (Mains power outage): Automatic transition via Static Transfer Switch (STS) Seamless grid-tied/island mode transition Zero-interruption load support