The Application Of WIN-HV Inverter In Jinglan Group

The Application of WIN-HV Inverter in Jinglan Group

Abstract:

This essay mainly presents the successful application of WIN-HV inverter, manufactured by Shenzhen Winner S&T Co.,Ltd, in Jinglan Sanyuan Cement Co., Ltd, a unit of China’s leading cement producer Hubei Jinglan Group. Field operation shows the WIN-HV inverter has been making prominent contribution to Jinglan Sanyuan on aspect of energy saving.

Key word:

WIN-HV inverter, cement industry, energy-saving reformation

1 Prolegomena

China predominates nearly half of the world’s cement market, with its yearly cement output accounting for about 50% of the world’s total. Previous statistics show that in the four straight months since April, 2006, China produced more than 100 million tons of cement per month, and it produced a total of 650 million tons of cement in the first seven months of 2006, representing a year-to-year increase of 20.7%. However, an extremely serious problem lingers in the country’s cement industry -high energy consumption. China’s cement industry consumes about 15% more energy in average than other countries which own more advanced technique.

2 Introduction of Jinglan Sanyuan

Founded in May 2005, Jinglan Sanyuan is the largest cement producer in Hubei province, and ranks 31st in the country. It is also one of China’s 60 picked cement producers that are entitled to enjoy many preferential policies. Jinglan Sanyuan now owns one dry-process rotory kiln production line with a daily production capacity of 2000 tons and two vertical kiln production lines. Annual sales of its “Jinglan” branded cement amounts to more than one million tons.

The cement production process is also known as a high energy consumption process. As the new-type dry-process rotory kiln production line becomes more and more prevailing, the industry presents huge space for energy saving. Jinglan Sanyuan’s blower installed capacity accounts for 30%-40% of its total installed capacity, and the electricity consumption volume of the blower also takes up 30%-40% of the factory’s total. As the roll-grinding system becomes more and more popular, the ratio of electricity consumed by the blower surges as well. The motor is designed with full-load, but in actual operating process, wind volume and wind pressure vary as operating condition and output change. But as is known to all, the blower is square-ratio load. If converting the transmission system of the blower to AC governor system, the blower can produce the most appropriate wind volume and wind pressure according to various requirements by adjusting the speed of the motor. Thus energy previouly consumed by the valve and baffle plate can be saved. Jinglan Sanyuan has a 2000-ton-daily-production-capacity line, which adopts a 10kV/kW circulating fan motor. The company previously realized wind pressure adjustment by valve, which wasted a lot of electricity. Meanwhile, in this mode, the valve is vulnerable to be damaged, and control accuracy is also not quite satisfying.

   

3. Introduction of WIN-HV inverter

I Structure introduction

WIN-HV inverter presents the unique topological structure through serial connection of several power units. Each unit provides constant low voltage level output, and achieve the requested medium voltage output by adding to other units. Please refer to the diagram as following.

Take the 10kV inverter with nine serially-connected power units per phase as an example, each phase contains nine units with equivalent power, and phase voltage is 5773V. The effective output voltage Ve of each power unit is 641V. The manifold series structure not only enables the inverter to realize medium voltage output, but also helps to reduce pressure to the components and make the output waveform more perfect. And this structure can also prevent the grid from pollution and maintain the percent of input current harmonic distortion below the IEEE519-1992 standard of 4%. Output power factor is high, so there is no need to install the input noise filter and power factor compensation device; the output waveform is much close to sine wave, and no potential faults will occur such as motor overheat, torque fluctuation, noise interference, output dv/dt and common-mode voltage. What’s more, the inverter can be applied to asynchronous motors without an output filter.

II Reliability design

In order to prolong the service life of the inverter, the power units of WIN-HV inverter adopt redundancy design, with each phase made up of nine serially-connected power units. The inverter also adopts automatic bypass system to ensure reliability. When one power unit breaks down, the inverter will automatically bypass that unit. The bypass function can blank off on line the faulty unit and guarantee continuous operation of the inverter. Meanwhile, it can ensure output voltage and output current at each phase keep consistent, decreasing the forced outage rate to the maximum degree.

In addition, the inverter has installed manual bypass device as well. On condition that the inverter breaks down and stops running, the motor can manually switch to continue operation with industrial frequency. The industrial frequency bypass consists of three medium voltage isolating switches K1, K2 and K3. When the motor runs driven by the inverter, K1 is connected and K2 lies in the frequency conversion place. When the motor runs with industrial frequency, K3 is connected while K1 and K2 are disconnected.

4 Application

WIN-HV inverter was transported to Jinglan Sanyuan in Nov, 2007, installed in the middle of Dec, and went into trial run in Jan, 2008. During the trial run and commercial operation period, the inverter works smoothly, with high accuracy and reliability, helping Jinglan Sanyuan save a lot of energy and money. Please refer to the table below:

Content

Power (Kw)

Power Factor

Average Power Consumption Per Day   (Kw.H)

Average Power Consumption Per Year (Kw.H)

Annual Power Saving Volume
(Kw.H)

Power Fare
(Yuan/Degree)

Avera-Ge Saved 
Cost

Before reform

650

0.82

11544

4155840

 

0.6

 

After reform

650

0.99

7920

2851200

1304640

0.6

782784

Main features of WIN-HV inverter:

  • Easy to install, just need to install the inverter between the motor and the medium voltage switch cabinet.
  • Easy to operate. Operation just includes start, stop and frequency adjustment.
  • Stepless speed adjustment function, wide speed adjustment range, high precision and prominent applicability.
  • Perfect protection function, lower fault rate
  • The exhaust fan starts smoothly, with little starting current
  • There is no need for the motor to run continuously at high speed, making for marvelous energy saving.
  • There is no need for the motor to run continuously at high speed, making for marvelous energy saving.
  • Less vibration and noise, lower bearing temperature

5 Conclusion

Nowadays, furious competition exists in the cement industry, and cost can mostly determine the prospect of cement enterprises. WIN-HV inverter is helping Jinglan Sanyuan save power to the maximum degree, accordingly to reduce its production cost. Meanwhile, the adoption of WIN-HV inverter also help the cement producer enhance its production security and boost its output. So we believe that Jinglan Sanyuan will definitely have a rosy outlook.