The 1140V series of static variable frequency power supplies for electric motor testing is the serialized products of variable frequency power supply developed by our company specially faced with the type tests for electromotors and electric generators and predelivery tests, which is broadly used in all kinds of tests of asynchronous motors, variable frequency motors, synchronous motors and permanent magnet synchronous motors. The products of this series adopt the AFE four-quadrant rectification, common DC buses, three-level inverter double line contravariant and combined sine filter technique, which can not only provide high-quality variable frequency power supply for all kinds of electrical motor tests including 380V, 690V (including 690V) and 1140V directly, but can also provide high-quality variable frequency power supply for all kinds of electrical motor tests including 3000V, 6000V and 10000V through the output transformer. For many years, with the support of vast customers, the 1140V series standardized electrical motor test static variable  frequency power supply products of our company obtained the reputations from customers with the mature technology, advanced property, complete functions, good quality, compact structure, low price, convenient use and good service, etc., and have been broadly used in many fields including type tests of all kinds of electromotors and electric generators, predelivery tests and electrical machinery research and development. 

The input side of 1140V series static variable frequency power supplies for electric motor testing by CenteRole (Dalian) Co., Ltd.  consists of the AFE four-quadrant rectification, 2 sets of AFE four-quadrant rectifications are connected in series connection at the direct current side, and the middle point of junction forms a DC bus voltage with the amount of ±1000V after ground connection and provides a DC supporting voltage of 2000V for the three-level inverter at the exit side. The double AFE four-quadrant rectification makes the harmonic content in the input current of the power grid side little, the current nearly shows a sine wave, the capacitor voltage at the direct current side of the AFE four-quadrant rectification is strictly controlled according to the given voltage of the system, it is not affected by the voltage fluctuation at the power grid side and the change in the load at the contravariant exit side, and provides steady DC voltage source for the contravariant output. Considering the demands of electrical motor tests, it can conduct the unit operation tests as well as the two-shipper driving power assessment, the output of system adopts the output scheme with 2 sets of three-level PWM inverters with the same common DC bus  and structural parameter, when conducting single motor tests, a set of inverter can be used to connect to the power grid as the input rectification, and the other set of inverter is connected to the tested motor, the power flow is from the power grid to the motor, and all the powers consumed by the motor are from the power grid side. When conducting the motor power assessment tests, a set of inverter can be connected to the tested motor, and the other set of inverter is connected to an accompanying motor with the same power, the mechanicals of the 2 motors are connected to the same axis, the tested motor is operated by a set of inverter through driving force, the accompanying motor is operated by the electricity dragged by the tested motor, the inverter connected with the accompanying motor is under the rectification condition, at this time, the power flow is going in a ring between the tested and accompanying motors, the little power at the power grid side is simply used to supplement the “consumption” of the 2 groups of inverters and the 2 motors, then the power assessment test of motors will hardly absorb power from the power grid, namely the micro power dissipation. In addition, there is a sine wave filter set at the inverter of each set of 3-phase PWM, which can guarantee that the output voltage and current index can sufficiently meet the national standard and requirement of the motor tests, and this filter can also be joined up or by-passed through the switch based on the demands of tests. 

• Adopt AFE four-quadrant rectification technical scheme at the input side, the power factor at the grid side is high, the current harmonic on grid side is low, the public DC bus voltage is accurate and steady, and it is not affected by the network voltage and fluctuation of load, and the quality of output electric energy can be guaranteed. 
• Adopting AFE four-quadrant rectification technical scheme at the input side can realize the prompt braking of motor assembling unit. 
• The open-end combined panel design based on the public DC bus and panel can make the dilatation of combined cabinet of the system convenient. 
• Adopt the rupture disc DC supporting capacitor, the work is safe and reliable, and the service life is long. 
• Adopt the annular heat pipe radiator, the efficient of heat dissipation is high, and it is safe and reliable. 
• Adopt the three-level inverter circuit and optimized designed sine wave filter, the electric energy output quality can sufficiently meet the international and national standards and requirements for the motor tests. 
• The power modules are in common use and can change with each other, which is convenient for the maintenance of the system. 
• Adopt colored touch screen, and the human-computer interface is friendly. 
• Have perfect fault diagnosis, failure warning and fault protection function. 
• The technology is mature, the property is advanced, the functions are complete, the quality is good, the structure is compact, the price is low and the use is convenient. 

Environmental conditions 

Main technical specifications

Static variable-frequency power supply system of 1140V and 9400kVA electric machinery tests