1.Product Overview
      The 33kV high-voltage switchgear is a critical component in medium-voltage power systems, compliant with IEC 62271-200 standards. It employs air-insulated (AIS) or gas-insulated (GIS) technology in a modular, metal-enclosed design. The switchgear integrates essential components such as circuit breakers, disconnectors, earthing switches, current transformers (CTs), voltage transformers (VTs), protective relays, and metering devices within a single compact structure.

      Modern 33kV switchgear typically features a withdrawable (draw-out) design, where the circuit breaker is mounted on a removable truck for easy maintenance without disrupting adjacent circuits. The enclosure is constructed from galvanized steel or stainless steel, with internal compartments segregated into circuit breaker chamber, busbar chamber, cable chamber, and relay/control chamber, ensuring safety and compliance with IEC protection class requirements.

      For insulation performance, composite insulation technology is applied, with silver-plated copper conductors and epoxy resin insulators to ensure stability under harsh conditions. The mechanical endurance of primary switching devices exceeds 10,000 operations, with a full-rated short-circuit breaking capacity of 30-50 interruptions.

2. Product Functions
1).Protection Functions
      Overcurrent Protection: Time-inverse and definite-time characteristics via microprocessor-based relays
      Short-Circuit Protection: High-speed tripping within 3-5 cycles
      Earth Fault Protection: Zero-sequence current detection (directional/non-directional)
      Arc Flash Protection (Optional): Optical sensors for ultra-fast arc detection (<7ms response)

2).Measurement & Monitoring
      Three-phase current, voltage, power, power factor, and frequency measurement
      Energy metering (accuracy class 0.5S)
      Condition monitoring (breaker position, spring charge status, SF6 pressure, etc.)
      Temperature monitoring (busbar joints, cable terminations)

3).Control Functions
      Local/remote switching operations
      Auto-reclosing (optional)
      Five Safety Interlocks (IEC 62271-200 compliant):
      Prevent disconnector operation under load
      Prevent incorrect breaker switching
      Prevent energizing with earthing switch closed
      Prevent closing earthing switch on live circuits
      Prevent access to live compartments

4).Communication Features
      IEC 61850 protocol support
      RS485/Modbus interface
      Ethernet communication (optional)
      GOOSE messaging (optional)

       This 33KV switchgear design represents state-of-the-art medium voltage technology, combining proven reliability with modern digital control capabilities. The equipment is suitable for both conventional substations and smart grid applications, with optional condition monitoring systems for predictive maintenance strategies. All designs undergo complete type testing including temperature rise tests, short-circuit tests, and dielectric verification per relevant IEC standards.

1).Electrical Parameters
        Parameter Specification
        Rated Voltage 33kV
        Power Frequency Withstand Voltage: 70kV/1min
        Lightning Impulse Withstand Voltage:170kV
        Rated Current 630A–3150A
        Rated Short-Circuit Breaking Current 25kA / 31.5kA / 40kA
        Rated Short-Time Withstand Current 25kA / 31.5kA / 40kA (4s)
        Rated Peak Withstand Current 63kA / 80kA / 100kA

2).Mechanical Parameters
        Parameter Specification
        Mechanical Life Circuit Breaker: ≥10,000 ops; Disconnector: ≥2,000 ops
        Operating Mechanism Spring-operated / Motor-driven
        Opening Time ≤60ms
        Closing Time ≤100ms

3).Environmental Parameters
        Parameter Specification
        Ambient Temperature -25°C to +40°C
        Altitude ≤1000m (derating required for higher elevations)
        Relative Humidity Daily average ≤95%, monthly average ≤90%
        Seismic Resistance Horizontal: 0.3g; Vertical: 0.15g