ZW32-12F/630A Capacitor-powered Primary and Secondary Integrated High-voltage Vacuum Circuit Breaker

The ZW32-12 capacitor-powered primary-secondary integrated circuit breaker is a miniaturized intelligent pole-mounted switch device specially designed for 12kV (rated voltage 12kV) outdoor power distribution systems. This device integrates a high-voltage vacuum circuit breaker body (primary equipment) and an intelligent control unit (secondary equipment), realizing the deep integration of functions such as protection, control, measurement, and communication.

I. Core Composition and Working Principle

This circuit breaker adopts an integrated design and mainly includes the following parts:

Switch body: It adopts a three-phase pole structure with a built-in vacuum interrupter, which uses vacuum arc extinguishing technology to interrupt current, featuring strong interrupting capability and no explosion risk. A spring operating mechanism or a permanent magnet mechanism can be configured in the mechanism box.

Power-taking and measurement unit: It uses capacitive voltage division technology to collect voltage, and collects current signals through an electronic current transformer based on the LPCT (Low Power Coil) principle, or adopts an integrated current-voltage sensor to achieve high-precision, wide-range electrical quantity measurement.

Intelligent control unit: Also known as Feeder Terminal Unit (FTU), it is responsible for data analysis, logic judgment and command execution. It integrates telemetry and remote signaling functions, and supports remote monitoring and automated operation.

Its working principle is as follows: The measurement unit collects the three-phase current, voltage and zero-sequence signals of the line in real time; the control unit analyzes these data to determine whether faults such as overcurrent, instantaneous trip, and single-phase grounding occur; once a fault is confirmed, it sends a trip command to the switch body to achieve rapid fault isolation.

II. Main Technical Characteristics and Functions

Electrical parameters: The rated current is usually 630A, 1250A, 1600A; the rated short-circuit breaking current can reach 25kA or 31.5kA.

Intelligent protection functions: It has overcurrent protection, instantaneous trip protection, grounding protection (including independent zero-sequence protection or zero-sequence power direction protection), overvoltage/undervoltage protection, etc. It supports 0 to 3 automatic reclosing operations to restore power supply for transient faults.

Fault handling and data management: It can quickly detect and isolate phase-to-phase short circuits and single-phase grounding faults, and alarm via voice, SMS, etc. It has a built-in fault recording function, can store at least 60 historical event data, and is equipped with a backup power supply to ensure that data will not be lost after power failure.

Communication and integration: It supports multiple communication methods such as cable, optical fiber, 4G wireless (GPRS/GSM), and can be remotely connected to the power distribution automation master station system to realize two-way communication and "three remote" functions.

Environmental adaptability: It has a high protection level (IP65 or IP67), adopts a fully enclosed, moisture-proof design, and some models have built-in electric heaters. It can operate stably in environments with temperatures ranging from -30℃ to +60℃ and at altitudes of 3000m to 5500m in plateaus and high-humidity areas.

Structural features: The overall design is a pillar-type, miniaturized structure, using stainless steel box and encapsulated poles, with light weight, long mechanical life (up to more than 10,000 times), and is designed as a maintenance-free structure.

III. Typical Application Scenarios

This device is mainly used for the protection and control of 35kV power distribution lines, and is a key equipment for realizing Feeder Automation (FA). It is widely applied in:

Rural power grid transformation and urban power distribution networks.

Power supply lines of industrial parks, industrial and mining enterprises.

Outdoor power distribution occasions such as field operations.

Its core function is to realize rapid fault location and isolation, reduce the power outage range, and improve power supply reliability.

IV. Model Examples

Common models include ZW32-12/630-25, ZW32-40.5/1250-31.5, ZW32-40.5FG/1600-31.5KA, etc., where "FG" usually represents the model of a sectionalizing circuit breaker.