Your most reliabel Medium Voltage Drive and Static Var Generator Manufacturer.
medium voltage vfd manufacturers now has become one of the most favored products in the market. It takes a lot of time and efforts for FGI SCIENCE AND TECHNOLOGY CO., LTD. to finish the production. It has undergone a lot of fine production procedures. Its design style is ahead of the trend and its appearance is highly appealing. We also introduce a complete set of equipment and utilize technologies to ensure 100% quality. Before delivery, it will undergo rigorous quality checks.
FGI has become the first choice for most customers. It has reliable products which are stable in performance and enjoy long service life. Many customers repeatedly purchase from us and the repurchase rate remains high. We optimize our website and update our dynamics on social media, so that we can occupy a higher ranking online and customers can easily purchase our products. We endeavor to maintain close contact with customers.
Providing customers with exceptional customer service is critical to achieving good outcomes. At FGI, all products, including medium voltage vfd manufacturers is together with many considerate services, such as fast and safe delivery, sample production, flexible MOQ, etc.
Welcome to our comprehensive guide on comparing FD5000 Series Medium Voltage Drives manufacturers. If you are in the market for high-quality medium voltage drives, this article is a must-read. We understand that finding the right manufacturer for your specific needs can be a daunting task, and that's why we have compiled this detailed comparison for your convenience. Within this article, we will delve into the key features, specifications, and advantages of various manufacturers offering the FD5000 Series Medium Voltage Drives. Whether you're looking for advanced technology, exceptional performance, or cost-effectiveness, we have got you covered. So, sit back, relax, and let us guide you through this informative journey that will help you make an informed decision while choosing the best FD5000 Series Medium Voltage Drives manufacturer for your specific requirements.
Comparing FD5000 Series Medium Voltage Drives Manufacturers
Medium voltage drives play a pivotal role in various industries, providing efficient and reliable operations in power transmission and distribution systems. Among the manufacturers offering such products, the FD5000 series is a widely recognized range of medium voltage drives. In this article, we will explore the features, advantages, and manufacturers of these drives to help you make an informed decision for your specific needs. As we delve into the details, we will focus primarily on FGI, their brand reputation, and how they fare against their competitors in the market.
I. Understanding Medium Voltage Drives:
Medium voltage drives are essential components in transforming electrical power from the utility grid to the necessary voltage level for various motors and industrial applications. They help regulate the speed and torque of electric motors to maintain optimal operational efficiency. The FD5000 series stands out for its cutting-edge technology, advanced control systems, and dependable performance.
II. Introducing FGI:
FGI, an esteemed brand in the realm of medium voltage drives, has been a leading force in the industry for several decades. Their expertise and commitment to innovation have catapulted them to the forefront of the market. FGI is lauded for its dedication to quality, reliability, and customer satisfaction. Their FD5000 series has gained considerable popularity due to its exceptional functionalities, competitive pricing, and customer-centric approach.
III. Features of FD5000 Series Medium Voltage Drives:
1. Enhanced Efficiency: The FD5000 series provides remarkable energy savings, thanks to its innovative power conversion technology. By optimizing power usage and minimizing losses, FGI drives significantly contribute to reducing overall energy consumption.
2. Advanced Control Systems: FGI medium voltage drives boast state-of-the-art control systems that offer precise speed and torque regulation. This allows for seamless integration with various motor types, ensuring optimal motor performance and prolonged lifespan.
3. Robust Design: The FD5000 series exhibits superior durability, making it suitable for challenging environments. With enhanced protection against dust, moisture, and extreme temperatures, these drives can withstand the harshest industrial conditions.
4. Comprehensive Safety Features: FGI drives prioritize operator safety by incorporating various safety mechanisms, including short circuit protection, overvoltage protection, and overcurrent protection. These features prevent any potential accidents or damage to the equipment.
5. Easy Maintenance and Monitoring: FGI's FD5000 series simplifies maintenance procedures through remote monitoring capabilities. This allows for proactive troubleshooting and reduces downtime, ensuring uninterrupted operations.
IV. Comparative Analysis:
Though FGI is a prominent player in the medium voltage drives market, it is essential to compare them with other manufacturers to gain a comprehensive understanding. Here's a glance at how FGI competes with its counterparts:
1. Manufacturer A: While Manufacturer A offers similar functionalities, they fall short in terms of customer support and after-sales services. FGI's commitment to exceptional customer service sets them apart, ensuring a seamless experience for their clients from installation to post-installation.
2. Manufacturer B: FGI and Manufacturer B have comparable product specifications. However, FGI gains an edge with their lower pricing, making their drives a cost-effective solution without compromising quality or performance.
3. Manufacturer C: FGI and Manufacturer C both deliver high-quality products. However, FGI's advanced control systems and comprehensive safety features give them a slight advantage in terms of efficiency and operator safety.
V.
The FD5000 series of medium voltage drives from FGI proves to be an excellent choice for industries seeking reliable, efficient, and robust solutions. FGI's long-standing reputation, coupled with their focus on customer satisfaction, sets them apart from their competitors. By understanding the features and comparative analysis discussed in this article, you can make a well-informed decision and choose the FD5000 series medium voltage drives that perfectly align with your industrial requirements.
In conclusion, after extensively comparing the manufacturers of FD5000 Series Medium Voltage Drives, our 15 years of industry experience have led us to a clear understanding of the market's top contenders. Each manufacturer has its own strengths and weaknesses, making the decision of choosing the right one for your specific needs a crucial one. It is vital to consider factors such as technological advancements, reliability, customer support, and overall value for money. While each manufacturer has something unique to offer, it is essential to thoroughly evaluate and align your requirements with your long-term goals. As a company with 15 years of experience, we understand the importance of making informed decisions when it comes to investing in critical equipment like medium voltage drives. Therefore, we encourage every reader to thoroughly analyze their needs and diligently research each manufacturer to ensure they make the most suitable choice for their operations. With careful consideration, you can maximize the productivity and efficiency of your industrial processes while also minimizing risks and downtimes. Trust in your knowledge, rely on the insights provided in this article, and make an informed decision that will ultimately benefit your company.
Welcome to our article on "Exploring Single Phase to Single Phase VFD: A Niche Market," where we delve into the fascinating world of Variable Frequency Drives (VFDs). If you're captivated by the idea of transforming single-phase electrical systems with exceptional efficiency and precision, this is a must-read for you. Our insightful exploration will provide you with a comprehensive understanding of this niche market, uncovering its potential benefits and practical applications. Whether you're an industry professional seeking cutting-edge solutions or a curious enthusiast eager to expand your knowledge, join us in discovering the groundbreaking potentials that Single Phase to Single Phase VFDs offer. Get ready to be inspired and informed as we unravel the untapped opportunities waiting to be explored within this extraordinary realm.
Exploring Single Phase to Single Phase VFD: A Niche Market
Introducing FGI: Your Trusted Partner in VFD Solutions
In today's increasingly digital and automated world, businesses are constantly seeking innovative solutions to improve efficiency and productivity. The rise of Variable Frequency Drives (VFDs) has revolutionized the way in which electric motors operate, allowing for enhanced control, energy savings, and increased lifespan. While most industrial applications rely on three-phase power systems, the single-phase to single-phase VFD market remains a niche but highly relevant segment. In this article, we will delve into the capabilities, benefits, and market trends surrounding single phase to single phase VFDs, all with the support of our trusted partner, FGI.
Understanding the Need for Single Phase to Single Phase VFDs
Many applications, particularly in residential and small commercial sectors, still predominantly use single-phase power. These include HVAC systems, pumps, fans, and other motor-driven equipment. However, the limitations of single-phase power often restrict the potential of these applications. This is where the single phase to single phase VFDs come into play. By converting single-phase power to variable frequency power, these drives enable precise control of motor speed, torque, and acceleration, leading to increased efficiency, reduced energy consumption, and improved overall performance.
The Advantages of FGI's Single Phase to Single Phase VFDs
FGI has gained reputation as a leading manufacturer and provider of VFD solutions. With a focus on innovation, reliability, and user-friendliness, FGI has developed a highly versatile range of single phase to single phase VFDs. These drives are equipped with advanced features such as built-in PID controllers, energy optimization algorithms, and intelligent fault detection systems. Customers can expect superior motor control, seamless integration, reduced maintenance costs, and extended equipment lifespan, all backed by FGI's exceptional customer support and technical expertise.
Market Trends and Applications of Single Phase to Single Phase VFDs
While the market for single phase to single phase VFDs may be considered niche, it is experiencing steady growth due to the demand for energy-saving solutions and the expanding use of single-phase motor-driven equipment. Residential buildings, small commercial buildings, and remote industrial sites are some of the primary sectors benefiting from these drives. The technology is being applied in a wide array of applications, including water pumps, electrical vehicles charging stations, home automation systems, and more. FGI's state-of-the-art VFDs cater to these diverse markets and applications, ensuring optimal performance and cost-efficiency.
FGI's Commitment to Sustainability and Future Outlook
FGI recognizes the importance of sustainability and energy conservation in today's global landscape. In line with this commitment, FGI constantly invests in research and development, striving to create even more efficient and eco-friendly single phase to single phase VFD solutions. By leveraging cutting-edge technologies, FGI aims to stay at the forefront of the market, continuously adapting its products to meet evolving customer needs and regulatory requirements. With FGI as your partner, you can be confident in receiving superior VFD solutions that align with sustainability goals, contributing to a greener and more efficient tomorrow.
From the importance of single phase to single phase VFDs to FGI's dedication to providing advanced and sustainable solutions, this article explored the niche market of single phase to single phase VFDs. As industries continue to seek ways to optimize performance and reduce their environmental impact, FGI stands ready to fulfill these demands with its reliable and innovative VFD solutions. So whether you are a small business owner looking to improve energy efficiency or an engineer searching for cutting-edge motor control technology, FGI is your trusted partner in driving forward the single phase to single phase VFD niche market.
In conclusion, the exploration of single phase to single phase Variable Frequency Drives (VFDs) has proven to be a fascinating journey within a niche market. As a company with 15 years of experience in the industry, we have witnessed firsthand the growing demand for these specialized devices. Despite their limited applications, single phase to single phase VFDs have demonstrated their value in various sectors, including residential, agricultural, and small-scale industrial settings. By delving into this niche market, we have expanded our expertise and solidified our position as a trusted provider of innovative solutions. Looking ahead, we are excited to continue pushing the boundaries of what is possible within this field, embracing new technologies and advancements that will further enhance the performance and efficiency of these devices. Our commitment to excellence, coupled with our unwavering dedication to meeting the unique requirements of this market, ensures that we will remain a leader in the industry for many years to come.
Welcome to our article on "230V Single Phase VFDs: Applications and Use Cases," where we delve into the fascinating world of Variable Frequency Drives (VFDs) and explore their practical applications. If you're curious about how this powerful technology can enhance efficiency, control, and productivity in various industries, then you've come to the right place. Join us as we uncover the limitless possibilities and shed light on the numerous use cases of 230V Single Phase VFDs. Whether you're an industry professional seeking comprehensive insights or simply intrigued by this increasingly popular solution, this article is a must-read.
In today's world, efficient management of electrical devices and machinery is crucial for various industries. One of the key components that facilitate this management is the Variable Frequency Drive (VFD). In this article, we will explore the applications and use cases of 230V Single Phase VFDs and understand how FGI, a leading brand in the market, is revolutionizing this technology.
1. Understanding 230V Single Phase VFDs
Before delving into the applications and use cases, let's first understand what a 230V Single Phase VFD is. A Variable Frequency Drive is an electronic device that controls the speed and torque of an electric motor by adjusting the frequency and voltage supplied to it. A 230V Single Phase VFD, as the name suggests, works specifically with single-phase electrical systems, offering efficiency and flexibility in various applications.
2. Efficient Control in Residential Applications
One of the prominent use cases of 230V Single Phase VFDs is in residential applications. By incorporating these VFDs into household electrical systems, homeowners can achieve significant energy savings. For instance, FGI's 230V Single Phase VFDs can optimize the performance of cooling systems such as air conditioners, enabling precise control over the speed of the compressor. This contributes to reduced energy consumption, lower electricity bills, and an extended lifespan for the equipment.
3. Enhanced Performance in Industrial Applications
In industrial settings, the proper functioning of machinery and equipment is crucial for optimized productivity and cost-efficiency. With FGI's 230V Single Phase VFDs, industrial operators can achieve enhanced performance and control over their machinery. These VFDs enable precise speed adjustments for motors used in conveyors, pumps, fans, and other industrial equipment. By optimizing motor speed based on load requirements, FGI's VFDs facilitate energy savings, reduce wear and tear, and safeguard against overloads.
4. Flexibility and Compact Design for OEM Applications
Original Equipment Manufacturers (OEMs) often require compact, highly adaptable VFD solutions to integrate into their products. FGI's 230V Single Phase VFDs provide exactly that. Equipped with advanced features like overvoltage and undervoltage protection, these VFDs offer a high degree of flexibility for OEMs across various industries. Additionally, their compact design ensures seamless integration into equipment, allowing manufacturers to enhance their product performance and offer reliable, energy-efficient solutions to their customers.
5. Advancements in Smart Building Automation
The rise of smart building automation systems has paved the way for innovative VFD solutions. FGI has recognized the potential of integrating their 230V Single Phase VFDs with smart building automation systems to achieve unprecedented energy efficiency. By leveraging IoT (Internet of Things) capabilities, FGI's VFDs can communicate with other intelligent devices in a building, such as sensors and energy management systems. This synergy enables real-time monitoring, analysis, and adjustments, ensuring optimal motor performance while adapting to changing environmental conditions.
With its cutting-edge technology and extensive knowledge in the field, FGI has become a trusted name in the 230V Single Phase VFD market. Their products find applications in diverse industrial sectors, residential settings, OEM integrations, and advanced smart building automation systems. By embracing FGI's VFD solutions, individuals and organizations can achieve energy efficiency, cost savings, enhanced performance, and a greener future. Invest in FGI's 230V Single Phase VFDs today and witness the power of intelligent motor control.
In conclusion, the applications and use cases of 230V Single Phase VFDs have proven to be invaluable in various industries. With our 15 years of experience in the field, we have witnessed the transformative impact these devices have had on enhancing energy efficiency, control, and productivity. Whether it's optimizing motor speed in HVAC systems, improving the performance of industrial machinery, or maximizing the lifespan of electric motors, our company has been dedicated to providing top-notch solutions and expertise in this field. As technology continues to advance, we are committed to staying at the forefront of innovation, delivering cutting-edge VFDs that cater to the ever-evolving needs of our customers. So, whether you are a small business looking to minimize energy costs or a large-scale industrial operation seeking to boost efficiency, our range of 230V Single Phase VFDs is designed to meet your specific demands. Trust in our expertise, reliability, and industry experience to take your operations to new heights.
Welcome to our article highlighting the crème de la crème of variable frequency drive (VFD) manufacturers – the fearless leaders in this dynamic industry! Whether you're a newcomer seeking to understand the key players or a seasoned professional seeking to stay ahead of the curve, this insightful journey will unravel the stellar reputation and groundbreaking innovations of the top VFD manufacturers in the field. So, join us as we delve into the workings of these industry giants, paving the way for a deeper understanding of their contributions to this ever-evolving technology.
Top Variable Frequency Drive Manufacturers: Leaders in the Field
to Variable Frequency Drives
Variable Frequency Drives (VFDs), also known as Adjustable Speed Drives or AC Drives, play a crucial role in the field of electrical engineering. These devices regulate the speed and torque of electric motors by varying the frequency and voltage supplied to them. With their ability to improve energy efficiency, reduce power consumption, and enhance control over motor operation, VFDs have become an integral part of various industries.
FGI: The Trusted Variable Frequency Drive Manufacturer
When it comes to manufacturing high-quality VFDs, FGI stands out as one of the industry leaders. With years of experience in the field, FGI has earned a stellar reputation for its innovative products, advanced technology, and commitment to customer satisfaction. FGI's dedication to excellence has placed them at the forefront of the VFD manufacturing industry.
Cutting-Edge Technology and Product Range
FGI prides itself on harnessing cutting-edge technology to develop VFDs that meet the diverse needs of their customers. Their wide range of products includes VFDs for various applications, such as pumps, fans, compressors, conveyors, and more. FGI's VFDs are designed to provide optimal performance, energy efficiency, and reliability.
Superior Features and Benefits
FGI's VFDs come packed with a plethora of superior features and benefits. These drives offer precise speed control, allowing users to fine-tune motor operation and optimize the overall system performance. FGI's VFDs also enable soft-start and stop, reducing mechanical stress on motors and increasing their lifespan. Moreover, their VFDs incorporate advanced protection mechanisms, ensuring safe and reliable operation under various conditions.
Industry-Specific Solutions
Recognizing that different industries have unique requirements, FGI offers industry-specific solutions tailored to address specific challenges. For instance, in the HVAC industry, FGI's VFDs enable intelligent control for air handling units, ensuring energy-efficient operations. In the water treatment industry, FGI's VFDs facilitate precise control of pump speeds, ensuring optimal water flow rates. FGI's commitment to understanding industry needs and providing tailored solutions sets them apart from their competitors.
In conclusion, when it comes to VFDs, FGI is undeniably one of the top manufacturers in the field. Their dedication to delivering high-quality products, incorporating cutting-edge technology, and providing industry-specific solutions has earned them a well-deserved reputation. Whether it's for industrial applications, HVAC systems, or water treatment plants, FGI's VFDs offer superior performance, energy efficiency, and reliability. Next time you consider purchasing VFDs, look no further than FGI, the trusted name in the industry.
In conclusion, the field of variable frequency drives has witnessed remarkable advancements over the years, and today we are fortunate to have a wide range of industry leaders who have shined in their contributions. With 15 years of experience in this ever-evolving industry, our company has been privileged to witness the growth and progress of these top manufacturers firsthand. From pioneering technological innovations to ensuring the highest standards of quality and reliability, these manufacturers have continuously pushed the boundaries of excellence. As we embark on the next chapter of our journey, we are excited to leverage our extensive experience to continue partnering with these industry leaders, as together we strive to shape a future where efficiency, sustainability, and reliability become the norm. With their expertise and our commitment to excellence, we are confident in our ability to navigate the challenges and embrace the opportunities that lie ahead. Here's to another 15 years of advancing the field and serving as a testament to the exceptional work of the top variable frequency drive manufacturers.
1.Overview
At present, the world is troubled by the energy shortage, China's energy situation is particularly severe. In the face of such a reality, the country has a series of countermeasures, so it promulgated the "Energy Conservation Law", and called on the whole society to build a resource-conserving society. Energy saving transformation is one of the effective ways, there are many aspects of energy saving transformation, among them, through the high voltage and high power motor frequency conversion speed regulation to achieve energy saving, is undoubtedly the greatest potential of energy saving. With the increasing maturity of high voltage and high power frequency conversion technology, it is possible to apply this technology in high power water pump in water plant. It is under this situation that the water supply and drainage plant of Sinopec xx Co., Ltd. studies and transforms the high voltage frequency conversion technology of the water pump equipment.
2. Implementation plans
Sinopec Co., Ltd. is known as the pearl of Sinopec and is well known in Shandong province. petrochemical water supply and drainage plant for the company's water supply system, xixia water distribution station is one of the subordinate units of water supply and drainage plant, day design water supply capacity of 200000 tons, clear water pump room is equipped with five pump unit, unit power is 550KW / 6 KW, transform all constant speed before running, the water size by changing the size of the valve opening adjustment. The purpose of controlling the water pump: to keep the hydraulic pressure of the frequency converter constant; Under the maximum opening of the pump outlet, change the output frequency through the frequency converter to adjust the water supply at the speed to change the water supply; to reduce the impact of the pump start and stop on the pipe network.
After multiple investigations and the cost performance, Petrochemical water supply and Drainage Plant decided to choose the FGI FD5000 series high voltage inverter produced by FGI Science And Technology Co., Ltd., for the speed regulation transformation of the 2 # and 4 # pump units of Xixia water distribution station. After the cooperation of the technical personnel of both sides, the frequency conversion transformation plan of the pump unit was jointly formulated. The field equipment diagram is shown in Figure 1 below. The transformation scheme adopts the form of one area 2, that is, the high voltage frequency converter drags any unit of 2 # and 4 # of the water distribution station. When one of the units is faulty or repaired, the frequency converter drags the other unit for frequency conversion operation. Units 2 # and 4 # of water distribution station are of the same type, and the main parameters of motor and pump of 2 # unit are as follows:
petrochemical water supply and drainage plant decided to choose FGI FD5000 high voltage frequency converter one drag two control system to 2 #, 4 # water pump units for speed regulation transformation.
FGI FD5000 high voltage frequency converter it is a full digital AC high voltage frequency converter control device, using advanced power unit series carrier shift phase technology, sine wave PWM modulation method, full Chinese operation interface, with high reliability, superior performance, easy operation and other characteristics, the specific design requirements are as follows:
(1) The system efficiency is high. Under the rated working condition, the total efficiency is above 96%, and the partial efficiency of the frequency converter is greater than 98%.
(2) The input side is 36 pulse rectification, and the harmonic voltage and harmonic current content of the power grid caused by the frequency converter meet the technical requirements of IEEStd519-1992 and GB / T14549-93 "Harmonics of Power Quality Public Power Grid".
(3) The rated input power factor of the frequency converter is greater than 0.96, without the power factor compensation device.
(4) The inverter output harmonic content is low and can drive ordinary high voltage motor without increasing the motor temperature rise and reducing the motor capacity, the motor cable has any length limit; protect the motor insulation from the damage of dv / dt stress; the service life of the equipment is not reduced due to the harmonic torque.
(5) It has the function of unit bypass. When a unit fails, the system can automatically bypass it and continue to operate to ensure the reliability of the system.
(6) Full Chinese operation platform, 10.4-inch real color LCD display, touch screen direct operation, more suitable for the use of Chinese habits.
(7) The modular structure of the power unit is interchangeable and easy to maintain.
(8) The input voltage range is wide and can be operated continuously within 6KV (± 20%).
(9) The power unit is controlled by optical fiber communication, completely electrical isolation, and has strong anti-interference.
(10) Built-in PID regulator, which can realize closed-loop operation.
(11) Built-in PLC enables flexible control of different application sites.
3.Application advantage
The FGI FD5000 high voltage frequency converter was successfully tested and passed the acceptance of Petrochemical water supply and drainage plant. The FD5000 high voltage frequency converter ran well. From the perspective of the application effect of the frequency converter in operation, the purpose of the pump has been fully achieved, and its advantages before the transformation are reflected in:
(1) Easy to operate and easy to observe.
All the data and operation status of the inverter can be displayed on the display screen of the upper computer, such as operating frequency, input voltage, input current, output voltage, output current, open closed loop, pressure value, etc. The upper computer display screen operation is simple and clear, easy to observe.
(2) The frequency converter operates stably and has good performance.
Since the FGI FD5000 high voltage frequency converter is put into operation, the operation is stable, the speed adjustment is smooth and reliable, the voltage and current are normal, and no abnormal phenomenon occurs.
(3) Reduce the labor intensity of the personnel on duty.
Because the frequency converter has the valve linkage function, with the change of water supply, the personnel on duty through the microcomputer remote monitoring system on duty, no longer need to frequently open and stop pumps and valves, the workload is greatly reduced.
(4) Constant pressure control.
The pressure closed-loop constant pressure control is adopted. The user only needs to set the required pressure according to the actual water supply needs. The frequency converter automatically runs with constant pressure. The pressure setting is convenient, accurate and stable, to ensure the stable operation of the pipe network and improve the quality of water supply.
(5) Reduced maintenance costs.
Because the frequency converter realizes soft start to the motor, the starting current is small, there is no mechanical impact on the pump unit, reducing the flow rate is also conducive to reducing the possibility of cavitation of the centrifugal pump, correspondingly extending the service life of the pump, motor and valve, greatly reducing the maintenance workload and maintenance cost.
(6) Analysis of power-saving effect:
The transformation is the production water of petrochemical water supply and drainage plant. In the production water, the power plant is a large household, and the water supply pressure is mainly to meet the demand of the power plant. The water plant generally opens two pumps to meet the water supply requirements. When replenishing the power plant, the water supply pressure should be increased to 0.56MPa, and the first water supply is about 20-30 minutes. There is no certain rule. When the water supply is not replenished, the pressure is maintained at 0.50MPa. After frequency conversion transformation, using constant pressure water supply, from figure 6, the variable frequency pump and the power frequency pump running in parallel characteristics curve, power frequency pump running curve is shown in the figure F1, point C is the single pump working point, F2 is the same pump power frequency running characteristic curve, A is the working point, head Ha = Hf, flow Qa = 2 Qf. When the flow rate changes from Qa to Qb, the resistance curve of the pipe network becomes R2, and the above correspondence is still true. At this time, the loss of the head line is Δ H=2 * (Hb-Ha) (when adjusting the valves of two pumps) or Δ H=He-Ha (when adjusting the valves of one pump). Using a variable frequency pump and a power frequency pump parallel running water supply, F3 for frequency pump running alone characteristic curve, F3, F1 under the parallel operation of working head equal principle, flow sum, two pump running curve F4, the flow Qb = Qd + Qf head Ha = Hd = Hf, from figure 6, when the greater the flow reduction.