I. Overview
The CY20 spring hydraulic operating mechanism is an important component of the high-voltage circuit breaker spring hydraulic operating mechanism, and is a core control component for large-scale high-voltage transmission and transformation equipment. Especially, the YT-80 spring hydraulic operating mechanism with self-defense capability is one of the important conditions related to the safety of the power grid. For a long time, no good solution has been found both domestically and internationally, posing a great threat to the safe operation of the power grid.
The CY20 spring hydraulic operating mechanism is a product invented and developed by our company. Its performance adopts a unique on-off delay technology, which meets the self-defense capability requirements of high-voltage circuit breakers. It has the advantages of reasonable structure, advanced performance, stable on-off time, and high reliability.
2、 The main technological innovation points of the product
1. Innovatively adopting a combination structure of energy storage and working cylinder in the main structure;
2. Compared with similar foreign products, its performance indicators have the advantages of fewer seals, fewer components, lower cost, better processability, simpler structure, and higher reliability;
3. Especially, the design of its hydraulic system with added self-defense capability structure has advantages over similar foreign products, such as stable opening and closing time, small errors, simple structure, and low cost;
4. The sealing principle structure without external high pressure has been implemented in the design of the control valve, thus eliminating the possibility of dynamic leakage of high pressure. Designed according to the standards of the State Grid Corporation of China, the reliability of the overall structure has been greatly improved;
5. It can completely replace imported products.
3、 Basic principles and key technical content
The basic principle of this project is that the spring hydraulic operating mechanism mainly changes the quality and flow rate of high-pressure oil through the cut-off hole, controls the movement time of the piston rod, and delays the opening of the gate valve to ensure the closing opening time of the circuit breaker during the reclosing operation. Due to the use of hydraulic transmission principle, this device has high reliability, stable closing and opening time, and small error. After 5000 mechanical life assessments, the closing and opening time error is only 3ms. It fully meets the operating conditions of the circuit breaker model's reclosing operation for the second time, with three-phase synchronization not exceeding 3ms (required by the State Grid).
At present, the high-voltage circuit breaker operators operating in the power grid do not have self-defense capabilities, and the closing and opening times are controlled by time relays. Domestic manufacturers of high-voltage circuit breakers have not developed circuit breakers with true self-defense capabilities. Swiss ABB company uses the damping effect of the cut-off hole to drive the differential pressure to move towards the piston and drive the circuit of the stroke switch closing opening coil to achieve self-defense capability. Due to the arc factor during the stroke switch contact delay closing and the mechanical motion of the stroke switch, there are unstable factors, which make the closing opening time unstable, with large errors and low reliability. The closing opening time error is greater than 6ms, which cannot meet the operating conditions of the circuit breaker that the three-phase synchronization is not greater than 3ms during the second opening operation of the reclosing operation (required by the State Grid). The company's technical personnel, with years of experience, have developed an operating motor that meets the self-defense requirements of high-voltage circuit breakers. Its structure and technical performance are pioneering both domestically and internationally, and its technology is at the forefront of domestic and international standards.
4、 Main technical indicators
CY20 Spring Hydraulic Operating Mechanism Technology and Quality Indicators:
Opening power: CY20-4 6400J CY20-8 11000J
Closing power: CY20-4 2300J CY20-8 3500J
Rated voltage of opening coil: DC 220/110V
Rated current of opening coil: DC 1.6/3.2A
Rated voltage of closing coil: DC 220/110V
Rated current of closing coil: DC 1.6/3.2A
Opening time: 15~20ms
Closing time: 50-80ms
Opening and closing time: 0.28-0.3s
Self defense ability time (combined and divided time): 40-60ms (adjustable)
Self defense capability time error: ≤ 2 ms
Mechanical lifespan: 6000 cycles
Minimum operating voltage for opening: 45% of rated voltage
Minimum operating voltage for closing: 45% of rated voltage