However, the pain points amidst the glamour cannot be ignored: domestically produced wind power equipment has long been hampered by the lack of fully domestically produced components, preventing further cost reductions. This is particularly true for wind turbine pitch control systems, which have long been dominated by foreign brands. So, what exactly is a pitch control system? Why has this situation arisen? Are domestic companies planning to break through? Zhongcheng Excellence's mini-lecture series will discuss this topic.
Question 1: What is a wind turbine pitch control system?
The pitch control system is a crucial actuator for the control and protection of large wind turbine units, playing a vital role in the safe, stable, and efficient operation of the unit. Electric pitch control uses an electric motor as its power source. A servo driver controls the motor to rotate the output half-shaft gear of the reducer. This output half-shaft gear meshes with a gear inside the slewing bearing at the blade root, thus changing the pitch of the blades.
The electric pitch control system consists of a pitch controller, a servo drive, and a backup power system. It enables independent pitch control for all three blades, providing power output and sufficient braking capacity to the wind turbine, thus preventing damage from overload. The drive is the core component of the pitch control system; its platform-based product functionality not only covers the needs of all onshore and offshore wind turbine platforms but also helps reduce costs and further improves the reliability of the pitch control system and its adaptability to overall turbine control requirements. The pitch control system, combined with variable speed constant frequency technology, ultimately improves the power generation efficiency and power quality of the entire wind power system. Stable pitch control has become one of the hot topics and challenges in the field of large-scale wind turbine control and protection technology.
Question 2: What is the history of wind turbine pitch control systems?
As early as the 1990s, foreign countries began researching variable pitch control technology for wind power generation, mainly focusing on its operating characteristics and control strategies, and producing a batch of reliable wind turbine units. Currently, the research focus is on how to apply intelligent algorithms to wind power systems to enhance control performance. In 2009, 95% of the wind turbine units installed globally adopted variable pitch control. Since 2009, all MW-level wind turbine units installed in my country have also been variable pitch units.
Foreign researchers have achieved many research results in the study of variable pitch intelligent controllers. In addition, some foreign countries have developed a system that can assess and measure wind resources and perform computer simulations to verify the design theory of variable pitch stall control. It uses new wind turbine blade materials to develop wind turbines and low-speed permanent magnet generators with variable speed constant frequency control systems, which greatly improves the efficiency and reliability of wind power.
Question 3: Why is the wind turbine pitch control system so important?
The price of a wind turbine pitch control system accounts for only about 3% of the total price of the wind turbine, but this small control system is the master switch for starting and stopping the turbine blades, directly affecting the wind turbine's wind capture capacity and safe operation, and is crucial to the turbine's lifeline and profitability. Older wind turbine pitch control systems typically need to be replaced every two years, resulting in high maintenance costs and a short lifespan. Wind power generation belongs to a very complex heavy industry sector with a long industrial chain. From towers, blades, generators, gearboxes, and bearings, to large PLCs, pitch servo drives, high-power converters, SVG, plus transformers and converters, the entire product line covers multiple angles and levels of heavy industry. From a value perspective, industrial control products account for a relatively small percentage, only about 10%, but servo drives determine the reliability and stability of wind turbines. It can be said that control and drive products are the brain and heart of a wind turbine, a very core component.
With wind power entering an era of full grid parity, reducing the cost per kilowatt-hour has become essential for the sustainable development of wind power companies, whether for onshore or offshore wind power. Increasing the capacity of individual wind turbine units is currently one of the most effective ways to reduce the cost of offshore wind power. Innovations and breakthroughs in key technologies such as critical electrical control system components will become the key to success in the next era of wind power.
Question 4: Why have wind turbine pitch control systems remained dominated by foreign brands?
(1) my country started relatively late in this technological field, especially in the research on variable speed constant frequency control technology for megawatt-class and above high-power units, which is a recent development. This is twenty years behind advanced wind turbine technology countries. As mentioned earlier, my country's wind power manufacturing industry has only developed rapidly in the last four years since 2005. In order to quickly seize the market, major domestic wind turbine manufacturers have focused on expanding production scale and have no capacity to independently develop high-tech products such as control systems. Therefore, they mostly purchase products or import technologies directly from foreign companies such as MITA and Windtec. This has resulted in a high installed capacity but a lack of proprietary core technologies.
(2) From the perspective of the requirements of the wind turbine control system itself, it does indeed have its own unique characteristics and complexity. In terms of hardware, the wind turbine control system is installed along with the wind turbine in a near-natural environment, operating under complex conditions such as significant vibration, wide-range temperature variations, and strong electromagnetic interference. Therefore, its hardware requirements are much higher than those of general systems. In terms of software, for the wind turbine to achieve fully automatic control, a complete set of control software is required. The main control system, pitch control system, and frequency converter need to work together to achieve maximum wind energy capture at low wind speeds, constant speed at medium wind speeds, and constant frequency and power operation at high wind speeds. This requires an advanced and complex control algorithm in these major components. It will indeed take some time for domestic enterprises to fully master this technology independently.
(3) The wind turbine control system is a system highly integrated with the characteristics of the wind turbine. The control software, including the main control, pitch control, and frequency converter, is not only complex in algorithm, but also its various parameter settings are closely related to the wind turbine itself. The task of the wind turbine control system is not only to achieve highly automated monitoring of the wind turbine and power supply to the grid, but also to maximize wind energy capture and minimize load through appropriate control. Even if a general automation company can develop a prototype, it is difficult to verify it, let alone promote it. Small and medium-sized wind turbine manufacturers are unable to carry out such development.
Question 5: What is the current state of development of wind turbine pitch systems in China?
Currently in my country, the self-sufficiency of various components of wind power main control systems and pitch control systems is still unsatisfactory, including key hardware and control software. There remains a significant reliance on foreign brands, making it the weakest link in my country's wind power equipment manufacturing industry. Most domestic companies adopt a technology route of digestion, introduction, absorption, and reinnovation, resulting in a low localization rate, less than ideal localization effects, unsatisfactory operational performance, and widespread criticism of after-sales service.
As a core component of large-scale wind turbine control systems, pitch systems play a positive role in ensuring the safe, stable, and efficient operation of wind turbines. Currently, stable wind turbine pitch systems have become a key research project in my country's large-scale wind turbine control technology. From a business perspective, due to the relatively high capital and technological barriers to entry in the wind turbine pitch system industry, the number of domestic companies engaged in its production and manufacturing is limited, and the market concentration is relatively high, with market resources mainly concentrated in the hands of large leading enterprises. As critical components of wind turbines, the main control system and pitch system ensure the safe and reliable operation of wind turbines and improve wind energy utilization efficiency. Therefore, technological research and innovation in this field have attracted significant attention within the industry.
During the 11th Five-Year Plan period, my country's wind power equipment manufacturing industry achieved a leapfrog development from single-unit capacity to megawatt level. The gap between its R&D, design and manufacturing levels and the world's advanced levels has been rapidly narrowed. The technical capabilities of key components of wind power equipment have been rapidly improved. Through the efforts of the past few years, domestic enterprises have made positive progress in the development of major components of control systems and have basically formed independent technical development capabilities. What is lacking is mainly the large-scale commissioning performance of products and the accumulation of technology and experience.
Question 6: Why does Zhongcheng Excellence persist in China's wind power industry?
In the early stages of any industry's development, after the initial rapid adoption of imported technologies, a group of entrepreneurs full of ideals and innovative spirit participate. In the short span of less than 40 years of China's wind power industry development, many people have chosen to take a difficult path: independent innovation. Starting in 2014, along with the rapid development of China's second wave of wind power industry, Zhongcheng Zhuoyue also began to develop and produce pitch control systems. Every year, it launches new servo products and invests in the research and development of pitch control. In just a few years, it has obtained dozens of utility patents and design patents in the wind power field, quietly setting the goal of making domestic "affordable high-quality products with understated luxury".
Zhongcheng Excellence has a small but confident aspiration for itself: to uphold the banner of China's wind power and new energy in the world, and to make life better.
