CN-118641943-B - High-power synchronous motor test system

CN118641943BCN 118641943 BCN118641943 BCN 118641943BCN-118641943-B

Abstract

The application discloses a high-power synchronous motor testing system which comprises a tested motor M1, a test accompanying motor M2, an auxiliary test motor M3, a three-phase transformer, a first variable frequency power supply, a second variable frequency power supply and a voltage sensor, wherein the tested motor M1 is coaxially connected with the test accompanying motor M2, the auxiliary test motor M3 is coaxially connected with the tested motor M1, the first variable frequency power supply is connected with the auxiliary test motor M3 through a circuit, the auxiliary test motor M3 drives the tested motor M1 to synchronously rotate with the test accompanying motor M2, the output end of the second variable frequency power supply is connected with a primary side circuit of the three-phase transformer, the alternating-current end of the tested motor M1 is connected with one end circuit of a secondary side open winding of the three-phase transformer, the other ends of the secondary side three open windings of the three-phase transformer are connected with the alternating-current end circuit of the test accompanying motor M2, and the second variable frequency power supply acquires a three-phase voltage signal of the alternating-current end of the tested motor M1 through the voltage sensor. The application reduces the test cost and the harmonic wave influence.

Inventors

YUAN KAINAN
XUN QINGLAI
YUAN TAO
LUO HUA

Assignees

中机国际工程设计研究院有限责任公司

Dates

Publication Date: 20260512
Application Date: 20240528

Claims (8)

1. The utility model provides a high-power synchronous motor test system which characterized in that, including test motor M1, accompany test motor M2, auxiliary test motor M3, three-phase transformer, first variable frequency power supply, second variable frequency power supply, voltage and current's sampling circuit, wherein: the test motor M1 is coaxially connected with the test accompanying motor M2, the auxiliary test motor M3 is coaxially connected with the test motor M1, the first variable frequency power supply is in circuit connection with the auxiliary test motor M3 and is used for providing no-load rotation energy for the test motor M1 and the test accompanying motor M2, the auxiliary test motor M3 drives the test motor M1 and the test accompanying motor M2 to synchronously rotate, the output end of the second variable frequency power supply is in circuit connection with the primary side of the three-phase transformer, the alternating current end of the test motor M1 is respectively in circuit connection with one end of three open windings on the secondary side of the three-phase transformer, and the other ends of the three open windings on the secondary side of the three-phase transformer are respectively in circuit connection with the alternating current end of the test accompanying motor M2; The second variable frequency power supply injects a voltage vector into the primary side of the three-phase transformer, the voltage vector of the secondary side of the three-phase transformer and the output voltage of the alternating-current end of the tested motor M1 are overlapped to form a new output voltage vector, the amplitude and the phase of the new output voltage vector are adjusted within the allowable range of the capacity of the second variable frequency power supply and the capacity of the three-phase transformer, the output voltage of the alternating-current end of the tested motor M1 and the output voltage of the three-phase transformer are overlapped to be converged with the output voltage of the alternating-current end of the accompanying motor M2, and the loading of the tested motor M1 and the accompanying motor M2 is realized by adjusting the output of the second variable frequency power supply.
2. The high-power synchronous motor testing system according to claim 1, wherein, The maximum capacity of the three-phase transformer is less than or equal to 25% of the capacity of the tested motor M1.
3. The high-power synchronous motor testing system according to claim 1, wherein, The capacity of the first variable frequency power supply is 25% -30% of the capacity of the tested motor M1.
4. The high-power synchronous motor testing system according to claim 1, wherein, The second variable frequency power supply is used for providing a superposition vector for deflecting the alternating-current end voltage of the tested motor M1, and the capacity of the second variable frequency power supply is 25% -35% of the capacity of the tested motor M1.
5. The high-power synchronous motor testing system according to claim 1, wherein, The test motor M1 and the accompanying motor M2 are synchronous motors connected with respective excitation devices.
6. The high-power synchronous motor testing system according to claim 1, wherein, The tested motor M1 and the accompanying motor M2 are permanent magnet synchronous motors.
7. The high-power synchronous motor testing system according to claim 1, wherein, The second variable frequency power supply comprises a vector injection control module, and the vector injection control module comprises: The system comprises an active closed loop module, a reactive closed loop module, a power calculation module, a machine end voltage PLL module and an SPWM module, wherein: The power calculation module is used for calculating feedback reactive power Q back and feedback active power P back output by the synchronous motor for current i abc and voltage u abc acquired by the voltage and current sampling circuit; The machine end voltage PLL module is used for detecting and locking the amplitude u and the phase angle theta of the output voltage of the tested motor M1; The active closed loop module calculates an output correction angle delta theta through the given active power P ref and the feedback active power P back , the correction angle delta theta is limited to obtain delta theta 'and the phase angle theta output by the machine end voltage PLL module is added to obtain a modulation angle theta'; The reactive closed loop module calculates and outputs a correction voltage Deltau through giving a reference reactive power Q ref and a feedback reactive power Q back , and the correction voltage Deltau is limited to obtain a modulation voltage amplitude u 'by adding Deltau' and the amplitude u of the voltage output by the machine side voltage PLL module; the SPWM module generates three-phase voltage by using a modulation angle theta 'and a modulation voltage amplitude u' and injects the three-phase voltage into the primary side of the three-phase transformer to provide a superposition vector for deflecting the voltage of the alternating-current end of the tested motor M1.
8. The high-power synchronous motor testing system according to any one of claims 1 to 7, wherein a first gear box GBX1 and a second gear box GBX2 are further arranged between the tested motor M1 and the accompanying motor M2, the input end of the first gear box GBX1 is connected with the output end of the tested motor M1, the output end of the first gear box GBX1 is connected with the input point of the second gear box GBX2, and the output end of the second gear box GBX2 is connected with the input point of the accompanying motor M2 for forming a test for the gear box.

Description

High-power synchronous motor test system Technical Field The application relates to the technical field of synchronous motor testing, in particular to a high-power synchronous motor testing system. Background The motor test requires normal operation and requires a power supply. The power supply can use a common power grid or a variable frequency power supply with a control algorithm. The full-voltage starting motor of the power grid can generate great impact at the starting moment, the small motor with the power level of hundreds of kilowatts or below can be tested, the impact on the power grid can be accepted, if the motor with the power level of hundreds of megawatts is directly started, the great impact is brought to the power grid and a testing system (a wire inlet switch, a ferromagnetic original piece and the like), therefore, the testing of the large synchronous motor mostly needs to use a variable-frequency power supply, and the motor is driven by the variable-frequency power supply to carry out the testing. Early common ac line motors and gearbox test systems were shown in fig. 1 and 2. The tested motors M1 and M2 are coaxial and driven by the variable frequency power supply 1 and the variable frequency power supply 2, one power supply operates in a rotating speed mode to control the rotating speed of the corresponding motor, and the other power supply operates in a torque mode to control the torque of the corresponding motor. The rectifier provides a direct current bus needed by the variable frequency power supply, and the tested and accompanying test branches are converged at an alternating current inlet wire, wherein the tested motor is mainly used for feeding electric energy generated by the tested motor back to the power grid to form an energy loop. The energy transfer process is that a power grid- > rectifier x- > variable frequency power supply x- > tested motor- > coupling- > accompanying motor- > variable frequency power supply x- > rectifier x- > power grid, and convergence is formed on the power grid. This test topology has several drawbacks: a) The rectifier needs to provide the power of the tested motor or the power of the same level as the accompanying motor, full-power rectification needs to be used, for example, the tested motor is 10MW, the accompanying motor needs to be more than 10MW, the rectifier needs to have the power level of 10MW, and the price is high; b) The operation of two full power rectifiers in the system can cause harmonic distortion of the power grid. Disclosure of Invention The application provides a high-power synchronous motor testing system which aims to solve the technical problems that an existing motor testing topological structure is high in cost and harmonic distortion is easy to occur in a power grid. The technical scheme adopted by the application is as follows: The utility model provides a high-power synchronous motor test system, includes test motor M1, accompany test motor M2, auxiliary test motor M3, three-phase transformer, first variable frequency power supply, second variable frequency power supply, voltage sensor, wherein: The test motor M1 is coaxially connected with the test accompanying motor M2, the auxiliary test motor M3 is coaxially connected with the test motor M1, the first variable frequency power supply is in circuit connection with the auxiliary test motor M3 and is used for providing no-load rotation energy for the test motor M1 and the test accompanying motor M2, the auxiliary test motor M3 drives the test motor M1 and the test accompanying motor M2 to synchronously rotate, the output end of the second variable frequency power supply is in circuit connection with the primary side of the three-phase transformer, the alternating current end of the test motor M1 is respectively in circuit connection with one end of three open windings on the secondary side of the three-phase transformer, and the other ends of the three open windings on the secondary side of the three-phase transformer are respectively in circuit connection with the alternating current end of the test accompanying motor M2; The second variable frequency power supply injects a voltage vector into the primary side of the three-phase transformer, the voltage vector of the secondary side of the three-phase transformer and the output voltage of the alternating-current end of the tested motor M1 are overlapped to form a new output voltage vector, the amplitude and the phase of the new output voltage vector are operated in the capacity allowable range of the second variable frequency power supply and the three-phase transformer to be adjusted, the output voltage of the alternating-current end of the tested motor M1 and the output voltage of the alternating-current end of the accompanying motor M2 are overlapped to be converged, and the loading of the tested motor M1 and the accompanying motor M2 is realized by adjusting the output of the second variable frequency power supply.