12MW high voltage inverter nuclear power construction project
12MW high voltage inverter nuclear power construction project

Applications:Power Industry

Keywords:Inverter application cases

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Detailed introduction

Chaotic air and dirty water accompany the life of modern people. The rapid economic development has brought about the deterioration of ecological environment. Clean energy alternative to fossil energy is imminent! Along with the development of nuclear energy technology, China has taken the lead in mastering the third generation of nuclear power generation technology, and safer and more reliable use of nuclear power generation can be guaranteed. Shanghai Apollo Machinery Co., Ltd. is a high-tech enterprise dedicated to develop high-end pump products, with the "Civil Nuclear Safety Equipment Design/Manufacturing License" issued by the State Nuclear Safety Administration, the company has now become a specialized and intensive nuclear power product integration supplier, one of the major nuclear power equipment manufacturers in China, and one of the important bases of nuclear power supporting equipment production in Shanghai.


Project Profile

At the end of 2013, Apollo Machinery planned to build a special test station for megawatt-class nuclear power main feed pump. Previously, Apollo Machinery test station had already used one of our 4000kW high voltage inverters, and the stable operation for several years had strengthened our confidence, so we actively participated in the bidding for the 12000kW inverter system for this pumping station.

If this test station is completed, it will be the first time in the world to realize project testing of many nuclear power pumps in a pumping plant, setting an international precedent. The project has special requirements for inverter drives.


1) the inverter needs to have not only 12,000kW long-term operating capability, but also 10kV, 6.6kV and 6kV are available.

(2) Considering the certain destructive test work of the pump, with certain overload capacity.

(3) the pump needs to do long-term endurance test, considering the need for test energy saving, the inverter must have the ability to switch working frequency without trace (the total capacity of the customer's power grid is only 16000kVA), so the current cannot have a little impact when switching is required.

Project System Solutions

According to the customer's bidding requirements, we provide a complete high-voltage inverter system solution in combination with our technical advantages. The solution is based on the inverter as the main body, with the customer's external frequency bypass part, the switching part of the customer's motor selection, and the site power monitoring part.

Power supply section:Grid incoming 35kV, outgoing 10kV, with a capacity of 16000kVA.


Inverter section:It is the core of the whole system and adopts unit cascade structure. To ensure reliable heat dissipation of the unit, the unit adopts an innovative design of heat pipe heat sink, which greatly improves the unit heat dissipation area and ensures effective heat dissipation under full load or even overload.


Bypass section:It is to switch the load from frequency dragging state to industrial frequency dragging state. QF1 and QF3 have integrated motor protection devices to ensure reliable motor protection in industrial frequency state; long-term industrial frequency full-load operation test can save 288 degrees/hour of electricity for customers and reduce testing cost.


Switching section and field power detection section:The customer selects the type of load to be towed according to their actual requirements; since the current and power of M2 load needs to be monitored at 6kV or 6.6kV, the power monitoring section is added here.


After getting our proposal, Apollo organized a group of industry experts to certify and analyze the feasibility of the proposal, and requested us to conduct technical Q&A on the proposal on site. More than ten experts from the client side raised many professional questions about the project requirements and system solutions. All of them were described in detail and analyzed systematically, and gave satisfactory answers to the customers. Because of the special nature of the nuclear power industry, it is not always possible to apply for acceptance by the expert group, so in order to make the pump test pass the acceptance earlier, we are required to meet the delivery of the inverter within 3 months.


Figure 1 Inverter system scheme diagram



The company opened a green channel for the project from procurement, SMT, production, to all kinds of link testing, taking the project as the first. Through the joint efforts of all departments of the company, the customer factory was notified on time to complete the corresponding acceptance of the product:

(1) The inverter runs at full current, and the temperature rise of each unit meets the customer's requirements.

2)When switching without trace, the switching current has no obvious fluctuation, realizing the true sense of no trace.


Performed the first mission and witnessed the first set of auxiliary feed pumps in China pass the acceptance


The equipment arrived at the site, the civil construction of the site has been completed, and the installation, wiring and high voltage of the equipment were completed on time. The project entered the final critical commissioning stage. The first task received by the whole system is the first set of the first auxiliary feedwater steam pumping unit with China's independent intellectual property rights, and this project is one of the annual key projects of the client company. The test program is divided into two steps: static test and dynamic test. The so-called static test is the system of all the equipment on low-voltage control power, not high-voltage power, test the correctness of all the parameters of the system logic under static. The dynamic test is to test the mechanical and electrical performance of each link under the condition of load dragging.


The customer's technical personnel and our technical personnel started from static commissioning, each signal and each detail was carefully calibrated, and the data operation of each auxiliary equipment was checked. To the high voltage dynamic test, the field staff tested the real-time current and power of the inverter, the pressure of the pump, temperature rise and other key signals in real time. The data related to the pumps under different pressure conditions were tested through the inverter speed regulation. The whole set of pump set test was carried out until late at night, but the process was very smooth, and the parameters detected by the inverter basically matched with the values detected by the user's precision instruments, and the customer gave full recognition to the excellent performance of the inverter.

On July 2, 2014, the first auxiliary feedwater pump set with China's independent intellectual property rights was successfully accepted at Shanghai Apollo Machinery Co. This product fills the gap in China and is of great significance to promote the independent and localization of key core equipment of China's nuclear power plants, completely breaking the situation of monopoly by foreign manufacturers.



Figure 2 High voltage inverter room


Stable inverter dragging system helps pump acceptance success


After the successful completion of the first task, the high voltage inverter has completed many more test tasks. The technical person in charge of Apollo Machinery informed that the main feedwater pump set will be tested during the golden week, this project is the biggest project of Apollo Machinery in these two years, and it is also an important key node related to the important technology breakthrough of the localization of nuclear power industry. Due to the special nature of nuclear power industry, if the test is not completed on time and passed the appraisal, the project will be delayed until next year, which will cause incalculable loss. We hope that our technical staff will participate in the testing of the pump together. After the company leaders learned of this matter, they attached great importance to it and asked the project team to select technical backbone to participate in the testing of this project with Apollo Machinery.

The main water pump set consists of 2 pumps, one is the main feedwater pre-pump and one is the pressure level main feedwater pump. According to the requirements of the pump testing team, the two pumps were first tested separately, and the parameters of each pump were measured and recorded in detail. The combined power of the water pumps is greater than the rated power of the inverter, and the long-term operation must be switched to the working frequency state. When the water pump set was towed to 50Hz operation, all pipes, water pressure were already in the normal range and the test power had exceeded the rated power. Through the upper computer system provided by us, we issued a no-trace switching command, and the inverter locked the grid phase and volt value within 1 second, issued a bypass command, and successfully dragged the load to the working frequency state, and there was almost no fluctuation in the pump pressure gauge and flow gauge at the moment of switching.



Figure 3 Frequency converter start-up and switching current


At 23:32 on October 17, 2014, a historic moment, Shanghai Apollo Machinery Co., Ltd. successfully completed the thermal state test and thermal shock test of the main feedwater pump set, which passed the on-site nuclear power industry expert group appraisal. This destructive test is the first of its kind in any international water pump factory.

Ltd - the appraisal meeting of the main feed pump set prototype interconnection test and test circuit system of megawatt-class nuclear power plant was held in Shanghai on November 1, 2014, entrusted by the National Energy Administration and hosted by China Machinery Industry Federation, and the project was successfully passed!


Through the cooperation with Apollo Machinery Co., Ltd, we deeply appreciate that all industries are trying their best to create Chinese creation with independent intellectual property rights. As a national key support high-tech enterprise, Xinshi Delta takes national industry revitalization as its responsibility, independent innovation in electrical transmission and motion control industry, focus on transcendence, launch a series of high-quality products and technology with independent intellectual property rights, contribute to the strength of Made in China.