Medium-voltage circuit breakers improve power quality mainly through the following technologies and methods to ensure grid stability, reduce interference and optimize power supply reliability:
1. Fast fault removal and protection to shorten fault time: quickly detect and remove short circuits and ground faults (action time can be controlled within 20-50ms), reduce the duration of voltage sag, and avoid downtime of sensitive equipment (such as PLC, inverter).
Selective protection: cooperate with relay protection devices to achieve regional selective tripping, reduce the scope of power outages, and maintain the power quality of non-fault areas.
2. Suppress transient overvoltage
Phase selection and closing technology: by controlling the circuit breaker to open and close at the voltage/current zero point, avoid operating overvoltage (such as surge when cutting unloaded transformers or cables).
Install surge protector (SPD): work with the circuit breaker to absorb transient overvoltage caused by switch operation or lightning strike.
3. Reduce the impact of harmonics
Harmonic current detection and disconnection: Some intelligent circuit breakers (such as those equipped with harmonic protection relays) can detect excessive harmonics and operate to prevent the spread of harmonic pollution.
Use with filters: In harmonic-sensitive occasions (such as data centers), circuit breakers are linked with passive/active filters to isolate harmonic sources.
4. Voltage fluctuation and flicker control
Fast reclosing: Automatic reclosing (such as within 0.3 seconds) in case of transient faults to reduce the impact of voltage interruptions on users.
Dynamic voltage regulation (DVR) coordination: On the critical load side, circuit breakers and DVRs work together to compensate for voltage sags.
5. Real-time power quality monitoring: Integrated sensors monitor parameters such as voltage deviation, harmonics, and imbalance, and upload them to the SCADA system through IEDs (intelligent electronic devices).
Predictive maintenance: Prevent voltage fluctuations or arc faults caused by poor contact by monitoring the mechanical characteristics and contact wear of circuit breakers.
6. Distributed Energy (DER) Grid Connection Support
Microgrid protection: quickly isolate the island or reverse power supply fault of distributed power sources (such as photovoltaic and wind power) to avoid voltage fluctuations and frequency deviations.
Adaptive protection setting: dynamically adjust the protection parameters according to the grid operation status (such as bidirectional power flow) to maintain the power quality.
7. Reduce the impact of arc
Vacuum/SF6 circuit breakers: use medium with strong arc extinguishing ability to reduce the voltage distortion caused by arc reignition during disconnection.
Arc protection system: detect arc faults in the cabinet and trip quickly to avoid voltage sag caused by fault expansion.
Selection and optimization suggestions
Circuit breaker type: vacuum circuit breakers (low maintenance, high breaking capacity) or SF6 circuit breakers (high short-circuit capacity) are preferred.
Intelligent configuration: select circuit breakers with communication functions (such as IEC 61850) to achieve remote monitoring and rapid response.
System coordination: cooperate with UPS, STATCOM and other equipment to build a multi-level power quality management system.
Through the above measures, medium-voltage circuit breakers can not only protect power grid equipment, but also significantly improve power supply continuity, voltage stability and harmonic suppression capabilities, meeting power quality standards such as IEEE 519 and IEC 61000.
VSM-12 indoor permanent magnetic vacuum circuit breaker by Shaanxi West Power Tongzhong Electrical Co., Ltd. is used for rated voltage 12kV, AC 50/60Hz indoor switchgear, adopting monostable permanent magnetic actuator, frame one-piece layout, suitable for all kinds of industrial and mining enterprises, power grid equipment, trolley unit and KYN28A-12 switchgear supporting the use of the unit, but also can be used as a fixed unit with the corresponding position interlocking, used in the XGN2 and other Fixed cabinet.
VSM-12 indoor permanent magnetic vacuum circuit breaker has many advantages:
1.Stable and reliable:
the most monostable permanent magnetic actuator mechanism, the framework of the integrated layout, compared with the spring actuator mechanism to reduce about 60% of the parts of the mechanism, reducing the vast majority of mechanical failures, safe and reliable.
2.Good insulation performance:
the main conductive circuit adopts APG high-strength epoxy resin composite insulation type, with higher than the IEC standard insulation performance.
3.Wide range of use:
series products cover a wide range, from rated current 630A to rated current 4000A, from rated breaking current 20KA to 40kA comprehensive coverage; cover all environments within the altitude of 4500 metres.
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Contact: Ms.Grace Liu (Director of Sales Department)
Email:xdtz@westpowerelectric.com
Tel: +86 917 3661109 Fax: +86 917 6739416
Mobile: +86 18091765882(WhatsApp/Wechat/skype )
Website:https://www.xdtzelectrical.com
