Hydropower Generation Box-type Substation Product Introduction

1. Product Brief Introduction

The hydropower generation box-type substation is a complete set of step-up and grid-connected power distribution equipment customized for small hydropower and micro hydropower generation sites. It integrates core components such as step-up transformers matching water turbine generators, high and low voltage switchgear, grid-connected protection and measurement and control, metering and reactive power compensation, and lightning protection and grounding. Aiming at the characteristics of small hydropower with small capacity, decentralized layout, outdoor and waterfront installation, it realizes the full-process functions of grid-connected and off-grid operation, water and power co-generation, load protection of hydropower generation, and protection of the whole process. It is a pre-assembled, integrated box-type equipment with rainproof and waterproof performance, which meets the characteristics of on-site installation, commissioning and operation of hydropower generation. It is a special power distribution equipment for small hydropower and micro hydropower projects to connect to the power grid, connecting water turbine generators with public power grids/local power grids.

2. Scope of Application

• Small hydropower sites: Step-up and grid-connected power distribution for mountainous runoff hydropower stations, dam-type hydropower stations, and diversion-type small hydropower stations, with capacity matching 100-5000kVA
• Micro hydropower sites: Power distribution and grid connection for rural small and medium-sized hydropower stations, run-of-river micro hydropower stations, and poverty alleviation supporting small hydropower projects
• Waterfront power generation sites: Outdoor waterfront power distribution for reservoir attached small hydropower, river channel small hydropower stations, and irrigation supporting hydropower generation
• Off-grid/grid-connected dual mode: Adapts to the power supply demand of small hydropower in remote areas with off-grid and grid-connected dual-mode operation
• Voltage level configuration: 0.4kV/0.69kV/10.5kV water turbine generator incoming line, 10kV/35kV grid-connected outgoing line, adapting to the step-up voltage demand of small hydropower main
• Supporting scenarios: Integrated supporting of electric control, step-up protection and electric energy metering for water turbine generators and water turbine units

3. Model Definition (Hydropower Special, Industry Universal Compilation Rules)

The model number of hydropower generation substation is compiled by prefabricated substation general code + hydropower characteristic code + voltage level + transformer capacity + extended function code. The core model such as YBM-SL-35/0.4-1000, each part of the definition is in line with hydropower step-up and grid-connected requirements, with high identification degree:

• YBM: General code for prefabricated box-type substation (Y - Prefabricated, B - Substation, M - Sealed type, adapted to outdoor waterfront environment)
• SL: Special characteristic code for hydropower generation (S - Hydropower, L - Power generation), distinguished from the core identification mark of ordinary industrial/photovoltaic substations
• 35/0.4: Rated voltage, 35kV/12kV (10kV power grid) on high voltage grid-connected side, 0.4kV/0.69kV (standard voltage of water turbine generator) on low voltage generator side; small capacity is marked as 12/0.4
• 1000: Rated capacity of step-up transformer dedicated to hydropower, unit kVA, common specifications for hydropower are 100/200/500/800/1000/2000/3150kVA
• Extended code: B - Grid-connected type, L - Off-grid type, S - Waterfront enhanced type, Z - Intelligent measurement and control type, F - Lightning protection enhanced type, marking hydropower special scene/function characteristics

4. Main Technical Parameters

4.1 Low Voltage Side (Water Turbine Generator Incoming Line, 0.4kV/0.69kV)

• Rated Voltage: 400V/690V/1050V (adapted to different power water turbine generator outputs, mainstream 0.4kV/0.69kV)
• Rated Current: 200A/400A/630A/1250A
• Grid-connected Protection: Standard configuration of active power protection, over-frequency/under-frequency protection, over-voltage/under-voltage protection, phase synchronization protection (core protection for hydropower grid connection), supporting low frequency shedding
• Measurement and Control Function: Real-time monitoring of generator voltage, current, active/reactive power, power generation, frequency, adapting to the speed fluctuation characteristics of water turbine generators
• Lightning Protection: Standard configuration of Class II surge protection device (SPD), nominal discharge current ≥60kA, incoming line side lightning protection and grounding, adapting to waterfront multi-thunder environment
• Metering Function: Standard configuration of hydropower special two-way energy meter, recording power generation/electricity consumption, complying with grid-connected electricity settlement specifications of power grid
• Outgoing/Incoming Line Circuits: 1-2 generator incoming line circuits, reserved 1-2 station service power circuits (self-use power of water turbine units)

4.2 Hydropower Special Step-up Transformer Part

• Type: Oil-immersed S14/S15 (mainstream for outdoor waterfront high-power hydropower, good heat dissipation, strong weather resistance), Dry-type SCB15/SCB16 (indoor/off-grid hydropower, no fire hazard)
• Rated Capacity: 100kVA-5000kVA (500-3150kVA commonly used for small hydropower, 100-800kVA commonly used for micro hydropower)
• Impedance Voltage: 6%-8% (10kV side), 10%-12.5% (35kV side), adapting to slight impact load of hydropower generation
• Connection Group: Dyn11/Yd11 (hydropower special, adapting to three-phase unbalance and speed fluctuation characteristics of water turbine generators, reducing voltage harmonic influence)
• Insulation Level: Oil-immersed Class A, Dry-type F/H level, temperature rise value meets the long-term load/light and heavy load alternating operation requirements of hydropower
• Cooling Method: Oil-immersed natural cooling (ONAN)/forced air cooling (OFAF), Dry-type natural cooling (AN), adapting to outdoor non-forced ventilation scenarios
• Protection Level: Transformer room IP54 (outdoor waterfront), Dry-type transformer IP23

4.3 High Voltage Side (Grid-connected Outgoing Line Side, 10kV/35kV)

• Rated Voltage: 12kV (10kV local power grid), 35kV (medium voltage power grid), adapting to the grid-connected voltage level of small hydropower
• Rated Current: 400A/630A/1250A
• Rated Short-circuit Breaking Current: 16kA/20kA (10kV), 12.5kA/16kA (35kV)
• Switch Type: Vacuum circuit breaker (VS1 type) / load switch-fuse combination electrical appliance, standard configuration of electric/manual operation, supporting remote closing and opening
• Grounding Mode: Neutral ungrounded / grounded via arc suppression coil (complying with grid-connected specifications of power grid), waterfront type is equipped with auxiliary grounding electrode
• Reactive Power Compensation: Standard configuration of SVG dynamic reactive power compensation device, compensation capacity 20-200kvar, power factor compensated to ≥0.95 (meeting hydropower grid-connected power factor requirements)
• Grid-connected Interface: Supporting connection with power grid dispatching system, equipped with grid-connected synchronization detection and closing interlock functions

4.4 Intelligent and Supporting Parameters (Hydropower Standard Configuration)

• Measurement and Control System: Hydropower special intelligent measurement and control terminal, monitoring generator/power grid two-side parameters and equipment operation status, real-time alarm in case of faults
• Communication Function: RS485/Modbus/4G/5G IoT module, supporting connection with power grid dispatching and hydropower monitoring platform for remote data transmission
• Station Service Power Supporting: Reserved 380V station service power circuit for power supply of auxiliary equipment such as water turbines, water pumps, valves
• Auxiliary Functions: Standard configuration of box body dehumidification, ventilation, anti-condensation devices, waterfront type with waterproof enclosure and anti-flooding structure
• Overall Protection Level: Outdoor waterfront IP65, conventional outdoor IP54, internal components IP33/IP43

5. Working Conditions

5.1 Environmental Conditions (Adapting to Outdoor Waterfront and Mountain Multi-thunder Characteristics of Hydropower Generation)

• Ambient Temperature: -30℃~+55℃ (temperature range design), withstanding extreme temperature difference in mountainous areas and high temperature environment in waterfront areas
• Relative Humidity: ≤98% (at 25℃), allowing short-term condensation and rain exposure, standard configuration of strong dehumidification device to prevent internal damp short circuit
• Altitude: ≤2000m (mainstream of mountainous small hydropower), customized design for altitude >2000m, adapting to high altitude mountainous hydropower
• Installation Environment: Outdoor hydropower station area/waterfront area, mountain hydropower station room nearby, adapting to dust, rain, fog, slight salt mist (riverside/river hydropower)
• Lightning Protection Requirements: Complying with "Code for Lightning Protection Design of Buildings", enhanced design for hydropower multi-thunder areas, grounding resistance ≤4Ω
• Vibration Impact: Withstanding normal operation vibration of water turbine generators (acceleration ≤2g), box body with shock absorption and anti-vibration structure
• Anti-flooding Requirements: The bottom of waterfront box body is treated with anti-flooding, height from ground ≥500mm, adapting to slight water accumulation in river channels during flood season

5.2 Electrical Working Conditions (In line with Hydropower Generation and Grid-connected Specifications)

• Power Frequency: 50Hz±2Hz, withstanding small frequency changes caused by water turbine generator speed fluctuation
• Voltage Fluctuation: ±15% on generator side, ±10% on power grid side, adapting to voltage fluctuation caused by hydropower head change
• Load Characteristics: Adapting to hydropower light/heavy load alternation, slight impact load, supporting long-term load and intermittent operation (run-of-river hydropower)
• Grid-connected Standard: Complying with "Technical Specifications for Grid Connection of Small Hydropower Stations" and "Technical Requirements for Grid Connection of Distributed Power Sources", equipped with grid-connected synchronization detection function
• Installation Method: Outdoor waterfront foundation ground installation (waterfront type waterproof foundation), indoor power station room installation, flatness of installation site ≤5mm/m, away from water turbine strong vibration source
• Execution Standard: GB/T 17467-2019 "Prefabricated Substations", DL/T 5164-2021 "Code for Design of Small Hydropower Projects", "Technical Specifications for Grid Connection of Power Systems"

6. Performance Characteristics

• Hydropower special adaptation and grid-connected compliance: Customized for water turbine generator speed/voltage fluctuation and water head change characteristics, standard configuration of active power, over-frequency, under-frequency, synchronization detection and other core protection for hydropower grid connection, all parameters comply with small hydropower grid-connected specifications, no additional equipment needed, direct grid-connected acceptance
• Weather resistance and waterproof, adapting to waterfront environment: Outdoor waterfront protection grade IP65, box body made of anti-corrosion cold-rolled steel plate + electrostatic spraying, bottom anti-flooding treatment, standard configuration of strong dehumidification and anti-condensation devices, withstanding harsh environments such as mountain high humidity, waterfront rain and fog, effectively preventing internal components from damp and corrosion
• Integrated assembly, high installation efficiency: Step-up transformer, grid-connected protection, metering and compensation, lightning protection and grounding and other components are fully pre-assembled and debugged in the factory, on-site only need to complete generator incoming line and power grid outgoing line wiring and foundation fixing, installation period 2-4 days, adapting to the characteristics of inconvenient hydropower transportation and limited working conditions
• Lightning protection enhancement, adapting to mountain multi-thunder scene: Double-layer lightning protection design for high and low voltage sides, incoming line side with auxiliary grounding electrode, grounding resistance ≤4Ω, targeted at mountain and waterfront multi-thunder environment, effectively avoiding lightning damage and improving hydropower station system reliability
• Reserved station service power circuit, perfect supporting: Reserved independent station service power circuit for water turbine unit self-use power, realizing integrated power supply of power generation, step-up and station service power
• Energy saving and consumption reduction, high power generation efficiency: Equipped with high-efficiency energy-saving step-up transformer for hydropower, standard configuration of SVG dynamic reactive power compensation, power factor ≥0.95, reducing hydropower transmission loss and improving hydropower station power generation and grid-connected efficiency
• Intelligent monitoring, convenient operation and maintenance: Standard hydropower special intelligent control system, real-time monitoring of generator/power grid side voltage, current, frequency, power and other parameters, fault real-time alarm, supporting 4G/5G remote communication, adapting to the demand of unattended and remote operation and maintenance of mountain small hydropower
• Compact structure, saving land resources: Compact box layout, floor area ≤5㎡, can be directly arranged in hydropower station area and waterfront area small sites, no need for additional power distribution room, adapting to the limited land resources of mountain small hydropower sites and saving land cost
• Long service life and high reliability: All components adopt industrial-grade products, withstanding slight vibration of water turbine generators and light/heavy load alternation of hydropower, long-term stable operation, high voltage side over-temperature, lightning protection and other complete protection, fault rate ≤0.2%/year, service life ≥20 years
• High customization degree, full coverage of small hydropower capacity: Transformer capacity covers 100kVA-5000kVA, supporting generator side 0.4kV/0.69kV and power grid side 10kV/35kV voltage level customization, available in off-grid, waterfront and other versions, adapting to the needs of different small hydropower projects (run-of-river/dam-type/diversion-type, off-grid/grid-connected, lightning protection enhanced type)