Product details

Overview

The general voltage protection switchgear for mining (GKYB-10 (A) for short) is suitable for use in non coal mine distribution rooms to limit various overvoltages in the power grid, which can improve the safety of power grid operation and the reliability of power supply. This device can replace the commonly used voltage transformer cabinets in the past.

Technical data

Rated voltage (maximum voltage) (kV): 10 (12)

Rated frequency (Hz): 50

Power supply voltage: AC/DC 220V+10%

Communication interface: RS485 or RS32

Communication protocol: MODBUS

Scope of application

This voltage protection switchgear is suitable for 10kV power systems in non coal mines and can replace voltage transformer

cabinets, dedicated lightning arrester cabinets, etc.

Product Features

1.Voltage protection switchgear is designed and produced according to the system parameters of different users

2. Eliminate the dead zone of system overvoltage protection;

3. Overvoltage in systems that absorb large amounts of energy;

4. Replaced PT cabinet, with high cost-effectiveness;

5. Real time monitoring of system status, accurate judgment of abnormal operating conditions, and timely output of corresponding switch contact signals for call the police;

6. The industrial standard RS485 communication interface can transmit the operating status of the system to the upper computer

7. Fault recall function, displaying the last 20 historical fault records;

8. Has good electromagnetic compatibility and is suitable for application in complex environments with strong electromagnetic interference;

9. Dual hardware watchdog circuit ensures the reliability of software operation

10. Chinese LCD display, clear operating status, menu style operation, convenient and easy to use.

Voltage protection switchgear function

1. It has all the functions of a voltage transformer cabinet.

2. When the voltage protection switchgear is running normally, the microcomputer protection device inside the cabinet continuously detects the voltage signal provided by the PT in real time. Once PT disconnection, overvoltage, undervoltage, low voltage, resonance, arc grounding and other phenomena occur, the microcomputer protection device uses DSP's high-speed and repetitive data processing capabilities to achieve Fourier analysis.

By collecting and judging the secondary voltage of the voltage transformer PT, it analyzes and judges the various states of the system in a timely and accurate manner, displays the fault category, and outputs corresponding contact signals for alarm. Simultaneously utilizing the powerful logical computing capability of MCU to quickly achieve functions such as LCD display, remote communication, and data protection.

3. There are several types of overvoltage in China's 3-35kV system, including operating overvoltage generated during circuit breaker operation, resonant overvoltage generated by capacitive components and nonlinear inductors under certain conditions, atmospheric overvoltage generated during lightning strikes, and arc overvoltage generated during single-phase grounding. At present, there is no complete protection plan for these overvoltages, which can lead to accidents such as cable blasting, motor insulation breakdown, lightning arrester explosion, and voltage transformer burnout. The causes of such accidents are not only related to the performance of the overvoltage protection devices installed in the system, but also to the complexity of the system itself, which has a significant impact on the selection of overvoltage devices. For different systems, when choosing

overvoltage protection, the type of transmission line, the network structure of the transmission and distribution line, the nature of the load, and the grounding method of the system need to be considered. For such a complex system, it is difficult to isolate the use of one or several overvoltage protection devices to comprehensively suppress various types of system overvoltages, and these overvoltage protection products produced by different manufacturers cannot match each other due to their protection characteristics, making it impossible to completely and effectively suppress system overvoltages.

The voltage protection switchgear is developed to address the current situation of overvoltage prevention and control in medium voltage systems.

This cabinet can eliminate the protection dead zone of overvoltage protection components and devices in the system, and optimize the protection characteristics of system overvoltage. The voltage protection switchgear adopts a specialized component developed and produced by our company, a peak overvoltage absorber, which can effectively smooth out the rising edge of overvoltage and flatten the voltage peak, and can withstand the huge energy generated by overvoltage. This specialized component matches the protection characteristics of the overvoltage protector and voltage protection switchgear produced by our company, and can comprehensively eliminate the dead zone of system overvoltage protection.

When the voltage protection switchgear is operating normally, the intelligent microcomputer device inside the cabinet continuously detects the voltage signal provided by the PT in real time. In the event of PT disconnection, overvoltage, undervoltage, undervoltage, resonance, metal grounding, arc grounding and other faults in the system. The intelligent microcomputer device utilizes the high-speed and repetitive data processing capability of DSP to achieve Fourier analysis. By collecting and judging the secondary overvoltage of the voltage transformer PT, it timely and accurately analyzes various states of the system, determines the fault situation of the system, displays the fault type, and outputs corresponding switch contact signals.

The device can achieve functions such as remote communication and data protection. At the same time, the voltage protection switchgear can be equipped with microcomputer harmonic elimination, low current grounding line selection, intelligent control and other devices, realizing multi energy of one machine and saving limited space on site.

Main components and their functions of voltage protection switchgear

1. Specialized voltage transformer

voltage transformers use dedicated anti saturation PT, which can minimize ferromagnetic resonance as much as possible. Provide secondary voltage and auxiliary secondary voltage signals to the protected system during operation.

2. Special voltage protection switchgear controller

Based on the signal provided by the voltage transformer, once PT disconnection, overvoltage, undervoltage, low voltage, resonance, arc grounding and other phenomena occur, the microcomputer protection device uses DSP's high-speed and repetitive data processing capabilities to achieve Fourier analysis. By collecting and judging the secondary voltage of the voltage transformer PT, it analyzes various system states in a timely and accurate manner, determines the fault situation of the system, displays the fault category, outputs corresponding switch contact signals for alarm. Simultaneously utilizing the powerful logical computing capability of MCU to quickly achieve functions such as LCD display, remote communication, and data protection.

3. Peak overvoltage absorber -SPA

The peak overvoltage absorber is an overvoltage protection device specially developed for voltage protection switchgear, which can suppress overvoltage spikes. The overvoltage protection device uses a specially designed zinc oxide valve plate, which can greatly reduce residual voltage values and limit various overvoltages between relative ground and phase to phase to the lower level allowed by equipment insulation. A square wave current of 2ms can reach 3200A.

4. High voltage isolation switch

Used to control the input and output of voltage protection switchgear. When the voltage protection switchgear needs maintenance or debugging, it is isolated from the system and forms a clear disconnection point.

5. One time harmonic eliminator XX

The XX primary harmonic eliminator can eliminate the ferromagnetic resonance generated by voltage transformers. Limiting the sudden increase in excitation current of the primary winding of a voltage transformer to prevent busbar short circuit accidents caused by insufficient energy to extinguish the arc after the fuse is blown due to the increase in current of the primary winding of the voltage transformer.

The device is installed between the PT neutral point and ground, using positive temperature technology and utilizing the damping effect of resistors to disrupt its resonance conditions and eliminate resonance. In normal operation, the resistance is 0 and does not change the zero sequence circuit of the PT, so it will not affect the measurement accuracy of the transformer and will not amplify the neutral point unbalanced voltage; When resonance occurs, the resistance tends to infinity, which is equivalent to the transformer not being grounded, thus destroying the zero sequence resonant circuit.

6. Instantaneous switch PTK

Parallel connection with a primary harmonic eliminator. When working normally, it is in the closed state. When the system experiences resonance overvoltage, the controller issues a command and the PTK quickly opens, activating the primary harmonic eliminator. Limit overvoltage.