Integrated Primary and Secondary Ring Main Unit Product Introduction

1. Product Brief Introduction

The integrated primary and secondary ring main unit is an intelligent integrated device launched in response to the requirements of the new national grid standard "Technical Standard for Primary and Secondary Integration of Distribution Equipment". It integrates combined voltage and current transformer, electric energy metering module, high-performance state acquisition terminal and other equipment, consisting of ring main unit unit, feeder unit, bus section (PT) unit, centralized DTU and connecting cable assembly. It can collect active power, reactive power, power factor, frequency, sequence current and sequence voltage, total line energy, electric energy metering functions, as well as upload line overpressure, undervoltage, overload and other alarms, realize fault location and processing, single-phase grounding fault detection and processing functions, and upload short circuit/ground fault events to meet the requirements of distribution automation.

2. Main Functions

• On the basis of the traditional DTU function, it adds the metering-grade line electric energy collection function, optimizes the judgment and positioning function of small current grounding fault, and improves the sampling frequency, making the fault waveform collection more realistic and accurate.
• Line energy collection function: The metering-grade electric energy collection module realizes real-time electric energy data collection on the line, including positive and negative active energy calculation and four-quadrant reactive energy calculation, thus realizing two-way metering function and supporting fixed value function;
• Small current grounding fault judgment and positioning function: By collecting and analyzing the data of phase current transformer and zero sequence current transformer, the control unit judges these characteristics through various algorithms, thus accurately locating the area where the fault occurs;
• Fault waveform recording function: Sampling is carried out at 128 points per cycle, and the complete recording of each channel waveform of 4 cycles before the fault and 8 cycles after the fault as well as opening and closing position and other information is uploaded to the station terminal to analyze the cause of the fault, and supports cyclic storage of 64 fault waveform records.

3. Main Characteristics

• Adopt voltage-time type electromagnetic mechanism or conventional spring operating mechanism;
• Equipped with conventional overcurrent protection, voltage-controlled type, distributed intelligent FA function;
• Adopt "centralized and decentralized" control and terminal, intuitive and easy to use;
• Adopt CVT electronic voltage sensing technology;
• Isolating knife and vacuum interrupter interlock;
• Super capacitor backup power supply, maintenance-free for the whole life cycle;
• Arbitrary combination of circuit breaker/load switch, flexible and convenient.

4. Functional Characteristics

• Adapt to the requirements of distribution automation, judge by the controller line voltage, realize on-site fault handling in cooperation with the substation through delayed closing, no need for backup battery, no dependence on the master station, and can realize complete distribution automation function on site;
• The design abandons the instability caused by the lead-acid battery protection device;
• Clear distribution automation system function, simple and convenient operation;
• Adopt spring operating mechanism to open and close the load switch/circuit breaker to meet the operation requirements of distribution automation;
• Adopt vacuum interrupter, SF6 gas insulation, no oil, high safety;
• Three-phase common box layout, epoxy resin casting outlet, fully sealed mechanism, military-grade aviation socket, overall sealing technology ensures product airtightness, excellent anti-corrosion performance, maintenance-free for 15 years;
• Built-in isolating switch and vacuum interrupter asynchronous operation, switch closing and opening force is small, high safety;
• Excellent sealing performance: It has an integrally formed shell with IP67 protection grade, the shell is made of die-cast aluminum stretched and integrally formed, so the shell is compact, airtight, high mechanical strength;
• Excellent maintainability: The load switch/circuit breaker main circuit, secondary components and operating mechanism are all sealed in SF6 gas (equal pressure), not affected by the external environment, stable and reliable in performance, maintenance-free.

5. Ordering Notes

When placing an order for the integrated primary and secondary ring main unit, please provide the following information to ensure that the product meets the actual use requirements:

• Exact product model and specification
• Required functional configuration (such as metering module, fault recording, etc.)
• Operating environmental conditions (if special requirements)
• Special technical requirements (if any)