The New Third Board will implement tiered power IC business asset management + capital management

In ten years, what changes will happen to your company? What changes will happen to the industry? What changes will be made to the national policy?

In ten years, if you focus on one thing, will you achieve good results?

Yachengwei (Shaanxi Chengwei Electronics Co., Ltd., stock code: 430552) tells you, yes.

This year is the 10th anniversary of Yachengwei's struggle. Yacheng Microelectronics, which started with integrated circuits, has long focused on the development of power IC research and development technology. In January 2014, it successfully entered the national SME share transfer system, which is now familiar to people. Three board.

After the listing, Yacheng Microelectronics developed more rapidly: the use of equity incentives to introduce high-end technical talents to join, established the company's technical level; constantly tapping the depth of the consumer electronics market, while focusing on the huge amount of electric light source in the field of lighting Market; the first to introduce linear drive architecture IC through subversive technology innovation, to promote the rapid penetration of LED in electric light source application with low cost, high reliability and easy automation production, in order to achieve a high degree of market share in the industry...

2015 is a recognized winter year in the LED industry. Prices are falling, gross profit is falling, and competition is intensifying. However, Yachengwei has little impact. Its 2015 annual report shows that in 2015, the company's revenue reached 51.143 million yuan, an increase of 89.48%, and the net profit reached 4.913 million yuan, an increase of 100.47%.

Good performance growth and a benign development track have enabled Yacheng Micro to enter the list of “2015-2016 New Third Board Most Investing Value” by Gaogong LED.

“Continuous profitability and high growth are the basic requirements for value investment.” Yu Yuanqiang, Chairman of Yacheng Micro, introduced that from 2013 to 2015, Yachengwei’s annual compound growth rate of operating income exceeded 50%, and profits increased significantly. In 2015, the growth rate reached 100%, and the return on net assets was greater than 10%. “These can all reflect that the company is in the high-speed growth stage and has investment value.”

A team with excellent management capabilities is an important factor in ensuring continued profitability. As a public company, Yachengwei has a complete organizational structure and its internal cohesion has been strengthened year by year.

Specifically, the diversity of the professional structure of board members determines the height and breadth of the company's strategic decisions. The mid-level team that has matured in ten years shows the depth of implementation.

With height, depth and breadth, it is more able to cope with the fickleness of the primary and secondary markets.

On May 27, 2016, the “Strategic Management Measures for Listed Enterprises of National SME Share Transfer System (Trial)” was officially released, and Yachengwei became one of the first 953 companies to enter the innovation layer.

"These three standards accurately reflect the business indicators that need to be pursued in the development of the new three-board company, and at the same time eliminate the financial-like enterprises into the innovation layer, also to encourage the development of the real economy's pragmatic decision-making." Yu Yuanqiang told Gaogong LED.

The three standards refer to the continuous profit in the last two years, the continuous increase in operating income in the last two years, and the average market value of the 60 market-making transfer days that have recently been sold are not less than 600 million yuan. These three indicators reflect the company's profitability, the company's growth, and the size of the company, all of which are the basic standards that reflect the company's investment value.

After the tiered system has been put on the market, the market generally expects follow-up supporting measures. Yu Yuanqiang is no exception. He believes that the stratification of the NEEQ will enable Yacheng's business strategy of asset management and capital management to be effectively implemented.

In fact, in September 2015 and June of this year, Yachengwei has used capital power to raise funds to open new projects for the company.

The development of power ICs has always occupied the main position of Yacheng Micro Business.

As LED technology and the market become more and more mature, under the low cost requirements, the electric light source market adopts a linear drive architecture in large quantities, while other lighting fixtures will continue to adopt switching power supply driver ICs.

From 2012, Yacheng Micro has positioned itself to focus on the application of electric light source market, and mainly promotes linear constant current drive IC. “We have been leading the thyristor dimming application of electric light source, and we are the first to enter the US dimming application market,” Yu Yuanqiang said. Yachengwei's products have unique product performance in bulbs, filament lamps and T-tubes. There are also very mature thinking in the reliability design of the floodlights.

"We are ready, we are serving our customers, we are accelerating the replacement of traditional lighting technology, without increasing the cost of use for end users." Yu Yuanqiang said.

For the customer's vision, continuous growth and renewal, this may be the reason why Yachengwei has become one of the most investment-oriented new three-board enterprises in 2015-2016.

I. Governing and safety system problems:

1. Insensitive to changes in load, changes in leaps.

2. The oil servomotor cannot fully open or fully close in static testing.

3. Turbine speed wave or power, thermal load wave.

4. Extraction or back pressure cannot work.

5. Governing valve seal is not tight.

6. Governing valve rod is leakage.

7. Emergency governor pilot valve, axial movement limiting device, startup valve, emergency shut off and reset device cannot switch latch.

8. Additional security oil pressure and safe oil pressure not be established or low.

9. Emergency governor pilot valve and security box operation under low speed.

10. Oil ejection test is failed.

11. Turbine oil servomotor LVDT setting.

12. WoodWard505.505E.SPC.CPCâ…¡parameters configuration setting.

13. The pulse oil pressure (signal oil pressure) of hydraulic spring type oil servomotor cannot be established or under the design value.

14. Closing time of the oil servomotor is too long.

15. OPC function cannot be used.

16. Rotary slide valve cannot be rotated.

17. Unable to run at full capacity.

18. Turbine load shedding with a speed large rise.

19. Adjustment of speed regulating system.

II. Main Stop Valve (MSV)

1. The MSV can`t be closed fully under hot condition.

2. The MSV shut down automatically after it open to a certain extent.

3. The MSV can`t be opened.

4. The MSV can`t be opened in position.

5. Large leak of steam.

6. Automatic closing device cannot be tested activities.

7. Automatic closing device can`t be opened in position.

8. The closing time of MSV / automatic closing device is too long.

III. Oil System

1. The pressure of HP oil pump can`t reach to the setting value.

2. The outlet pressure/ inlet pressure of turbine main oil pump is low.

3. Turbine lubricating oil pressure is low.

4. The temperature of turbine return oil is too high.

5. The oil cooler outlet temperature is too high.

6. The lubricating oil pump outlet pressure is low.

7. Three-way check valve jam.

8. It does not match the HP oil pump output and system.

9. Poor oil return.

10. Bearing pedestal oil leakage.

Electric governing reconstructing casus:

A power plant had a C25-8.83-0.981 type steam turbine generator set which made in 1990s. The turbine was a hydraulic governing type with a cam steam distribution structure. After ten years running, the turbine is insensitive to changes in load with a large running delay rate. And its thermal load self-tuning is not high with poor primary frequency modulation capability. When shed the partial load, the adjusting quality can not meet the operational requirements. Considering above conditions, we can improve the STG control level and its adaptability by reconstructing its governing system into DEH.

I. Introduction the governing principle of the original system

This is a full hydraulic implicated governing system. It was composed by governor oil pump, regulator (pressure transducers, pilot oil valve and oil servomotor), the pressure regulator, rotary diaphragm oil servomotor, synchronization and others. The turbine`s electric load and thermal load were controlled by two loops - speed regulation loop and pressure regulation loop separately. Speed regulation loop receives speed pulse signal (pump output pressure change amount) from governor oil pump and synchronizer given signal for controlling speed and electrical load. Pressure regulation loop receives given signals from extraction pressure and regulator. It used to control the extraction pressure and thermal loads.


1. Control procedure of speed regulation loop

As a hydraulic speed sensor, the governor oil pump measures turbine speed. The oil pressure difference between the inlet and outlet of governor oil pump is proportional to the square value of STG speed. When the speed change is little, the oil changes and speed changes can be down as a linear process. So we use it to make pulse signal of speed changing. One side of pressure transducer slide valve was controlled by speed pulse signal oil pressure, and other side was controlled by synchronizing accepting control operation signal spring force.


Pressure transducers spool valve controls the overflow of two pulse passages. When the governing oil pump pressure changing which caused by changed turbine speed, or pressure transducer spring force changed by operating synchronizer, the pressure transducer slide valve would move up and down. So the piston of oil servomotor would move by controlled oil servomotor`s inlet and outlet. It would drive governing valve and rotary diaphragm open or close in a same time. So we can regulate the turbine speed (in single-unit operation) or turbine load (in grid operation). When the piston of oil servomotor move, the overflow area of the feedback window was changed also. So the pulse oil gets feedback and return to the setting valve. The pilot oil slide valve would come back to middle position and the oil servomotor line is cut off and the STG would be in a new stable condition.


2. Pressure regulation loop

The pressure measure element is bellows-type regulator. The pressure regulator pulse signal is turbine extraction pressure. The function of bellows is changing the steam pressure into displacement and change the opening of the overflow window. It would causes the oil pressure changing of two pulse oil lines. The changing directions of two pulse oil lines are opposite because the changing opening directions of two overflow windows of pressure regulator are opposite. It means HP oil servomotor and LP oil servomotor moves in a same direction. It can change regulator spring preload by turning on the hand wheel on top the pressure regulator. So it can change the turbine extraction pressure. When the thermal load is incorporated heating network, it can translate regulator static characteristic curve, thereby changing the turbine thermal loads.


II. Electronic governing system reconstructing proposal and execution

When we reconstructed the steam turbine, it was still on running. So the reconstructing period would be as short as possible. After considering the reconstructing period and turbine governing control precision, we decided to dismantle synchronizer, HP oil servomotor, MP oil servomotor and regulator only and reserve the original security part and oil suppling system, so we can reduce work quantity. We used direct-acting oil servomotor with an independent oil source as DEH hydraulic actuator. We used Nanjing Sciyon DEH-NK series electronic governing system. After reconstructing, the turbine running stable and each operating parameters excellent.


1. Reconstructing items:

A. Dismantling parts:

a. HP oil servomotor,

b. synchronizer,

c. MP oil servomotor, d. Regulator


B. Reservation parts:

a. electric oil pump set,

b. oil ejector,

c. spill valve,

d. overspeed protection device (including emergency governor, emergency governor pilot valve, electrical overspeed protection devices, speed measuring devices, etc.),

e. start valve,

f. MP oil servomotor bracket and etc.


C. Increased parts:

a. HP oil motive cover and bracket,

b. MP oil motive cover,

c. regular screw rods of HP and MP oil servomotor,

d. DEH electric governing system and its hydraulic actuator,

e. regulating oil pipe line,

f. security oil line reconstructing,

g. speed sensor.


2. DEH-NK system introduction

The main function of DEH-NK system is control turbine speed, turbine load and etc. DEH system accept input signal from the site, for example: OPS (speed), MW (power), PC (extraction pressure) and various control command form operator via LCD also. The electro-hydraulic converter was controlled by settled valve operation control signal which sent out after internal calculation. The height of HP valve was controlled by hydraulic system and its actuator. So we can complete the starting up, speed up, grid connection, loading, extraction adjustment and other function of steam turbine. It can make operation, protection, control, monitoring against various of conditions, so it can ensure turbine running safety and reliable.


A. Main function introduction


DEH-NK electric governing system includes but not limits the flowing functions:

   â— Turbine reposition (pilot valve)

   â— Manual/ automatic speed up, steam turbine automatic start-stop function (start by learning curve).

   â— Inspection friction.

   â— Overspeed electrical protection test and overspeed mechanical protection test under DEH control.

   â— Automatic synchronization (provided interface which connect with synchronization device ).

   â— After connection to the grid, DEH automatically with the initial load in order to prevent reverse power running and it has a load limiting function.

   â— DEH can adjust STG load automatically according to the target value and load changing rate which all given by the operators.

   â— Main steam pressure control and limitation.

   â— Extraction controlling.

   â— Deciding whether to participate primary frequency adjustment according to the need.

   â— Fault diagnosis alarm.

   â— OPC overspeed protection (103% nH, close HP & MP valve, 110% nH, close all valves, shut down).

   â— Stop state can be simulated.

   â— Doing MSV and regulating valve tightness test.

   â— Modified parameters and configuration can be down in the engineering station.

   â— It has friendly interfaces with other systems , such as TSI, DCS.


   B. Technical Specifications

   â— Speed control range: 40 rpm ~ 3500 rpm, precision (1 rpm).

   â— Load control range: 0 ~ 115%, 0.5% precision.

   â— Diversity factor of the speed: 3~6%.

   â— Diversity factor of the extraction: 3~6%.

   â— Oil servomotor closing time﹤0.5s

   â— Speed up control accuracy: 1rpm

   â— speed overshoot in rated load shedding: (7% rated speed)

   â— Delay rate for regulating speed ≯0.06%

   â— Power load rate 50%, double the power. Cabinet power supply device 1: 1 redundancy, two AC power supply (one line is working transformer and one line is plant UPS).

   â— System MTBF > 20000 hours

   â— System availability: 99.9%.

   â— Each type of I / O module in the cabinet has a 10% reserve margin, each cabinet has a 10% reserve margin of module slot. DPU processor load <30%, memory load <50%, communication load rate of <40%.

   â— DPU 1: 1 redundant configuration. When the primary DPU fault, it can switch to standby DPU automatically and unperturbed.


3. EH hydraulic system introduction

   A. System components

   â— It is formed by two parts of electro-hydraulic actuators and oil source station.

   â— Electro-hydraulic actuator is component by a hydraulic cylinder, servo valves, electromagnetic valves and others. It has two type of successive regulated and two position control. It uses of oil servomotor with sophisticated high-pressure and fire-resistant technology.

   â— Oil source station was made by oil tank, high pressure gear pumps, motors, pressure switches, pressure regulator valve, accumulator and other components. It was used energy-saving and environmental protection technology to achieve miniaturization design. It is decentralized and integrated into the relevant electro-hydraulic actuators.


B. Characteristics of this system

   â— 100% continuously adjustable, closed-loop servo control system with high reliability.

   â— Dynamic response time is less than 20 ms and switching time can be less than 0.2 seconds.

   â— It is particularly suitable for off grid STG. The governing quality can meet the requirements of rapid response under off grid.

   â— Actuator is small with easy to install. So it is very easy to use on-site and maintenance.

   â— Actuator has a strong output stiffness. It can also be adjusted online according to the site with completely free from the type of load.

   â— Working fluid is environmentally friendly with no environmental pollution. It solves the problem of fire-resistant oil environmental pollution.


4. Executing processes and effect

A. project period: 7 days

   Considering the STG actual operation condition and economy, we sent engineers to enter into the site to collect the data of STG installation and operation after the project is determined. A best reconstructing proposal was made according to the actual situation. We allowed the STG to keep running, meanwhile we organized reconstructing content, prepared materials and made a reconstructing proposal. After communication, coordination and cooperation between the customer and us activity, we completed the electric governing reconstructing in one week since turbine shutdown. We improved the customer`s economic efficiency after generation and grid connection.


B. Turbine running condition after the reconstructing

   â— Speed control range: ± 2 rpm.

   â— Load Control range: ± 130KW

   â— Extraction control range: ± 0.02Mpa (g)

   â— Diversity factor of the speed: 5%

   â— Diversity factor of the extraction: 10%

   â— Oil motive closing time: <0.5 seconds

   â— Speed up rate control accuracy: 1 rpm

   â— speed overshoot in rated load shedding: 3190rpm

   â— Delay rate for regulating speed ≯0.06%

Governing System Care

Governing System Care,Profession Governing System Care,Electric Governing Reconstructing

Shandong Qingneng Power Co., Ltd. , https://www.steamturbine.be

Posted on