Test circuit and test method for multi-phase synchronous generator started by motor mode

Abstract

The invention discloses a multi-phase synchronous generator test circuit and test method for starting in a motor mode, which solves the problem that it is difficult to start a multi-phase synchronous generator in a low-frequency and low-voltage mode during a test. The circuit comprises a multi-phase synchronous generator (1) to be tested, a first DC excitation power supply (3), a second DC excitation power supply (4), a twelve-phase synchronous generator (5), an asynchronous motor (6) and a variable frequency power supply (7), wherein the second DC excitation power supply (4) is electrically connected to the rotor winding of the twelve-phase synchronous generator (5), the asynchronous motor (6) is electrically connected to the variable frequency power supply (7), the stator winding voltage output end of the twelve-phase synchronous generator (5) is connected to the stator winding voltage input end of the multi-phase synchronous generator (1) to be tested, and the first DC excitation power supply (3) is electrically connected to an exciter (2) provided on the multi-phase synchronous generator (1). The starting current is small and there is no loss of step during the starting process.

Description

Technical Field

[0001] The present invention relates to a test circuit of a multi-phase synchronous generator, and in particular to a test circuit and a test method of a multi-phase synchronous generator which is started and operated in a synchronous motor mode. Background Art

[0002] After the multi-phase synchronous generator is assembled, its vibration, noise, efficiency and other parameters need to be tested. Many test items require the tested synchronous generator to run in the state of a synchronous motor. When the synchronous generator runs as a synchronous motor, it has difficulty starting because it does not have the slip characteristics of an asynchronous motor. The prior art is: placing the assembled multi-phase synchronous generator on a test bench, powering the exciter carried by the tested multi-phase synchronous generator through a DC excitation power supply, and powering the stator winding of the multi-phase synchronous generator through a variable frequency power supply to form a stator magnetic field, so that it starts and runs in the operation mode of a motor, and realizes the test and collection of its parameters. In this process, the variable frequency power supply generally supplies power in a low frequency and low voltage manner to start the synchronous generator, so as to avoid a loss of step after the generator is started, resulting in failure to obtain the synchronous test parameters, and then gradually increasing the frequency and voltage of the variable frequency power supply to gradually increase the tested synchronous generator to the rated power. voltage and rated speed; since the variable frequency power supply cannot smoothly provide the starting frequency and voltage to the stator of the synchronous generator, the starting voltage and frequency obtained by the tested multi-phase synchronous generator have a step-jump phenomenon. In the test, the coordination of the stator and rotor frequency and voltage of the tested machine is often invalid. It is often necessary to try to change the starting frequency and voltage of the variable frequency power supply for many times before the tested synchronous generator can be successfully started; at the same time, due to the differences in the assembly of different tested motors, the starting voltage and frequency required in the test are also different, which also brings operational difficulties to the starting motor test of the tested machine; in addition, the existing multi-phase synchronous generators are three-phase, six-phase and twelve-phase, and the existing variable frequency power supply is a three-phase output, which can only provide three-phase power and cannot meet the power input requirements of the multi-phase generator; even if there is a variable frequency power supply that can provide multi-phase power, the quality of the multi-phase power it provides is too low to meet the requirements of the input power of the multi-phase generator and the test requirements of the twelve-phase synchronous generator cannot be met. Summary of the invention

[0003] The present invention provides a test circuit and a test method for a multi-phase synchronous generator started in a motor mode, which solves the technical problem that it is difficult to start the multi-phase synchronous generator in a low-frequency and low-voltage mode when performing a motor test.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] The overall concept of the present invention is: the output end of the stator winding of a twelve-phase AC synchronous generator is electrically connected to the output end of the stator winding of the multi-phase synchronous generator under test, and a DC excitation power supply is used to provide excitation power to the exciter of the multi-phase synchronous generator under test, so that the multi-phase synchronous generator under test works in the state of a synchronous motor; the rotating shaft of the twelve-phase AC synchronous generator is connected to the rotating shaft of an asynchronous motor that drags it through a coupling, and a variable frequency power supply is connected to the asynchronous motor. The variable frequency power supply drives the asynchronous motor to rotate, so that the speed of the asynchronous motor can be continuously increased from 0, so that the twelve-phase AC synchronous generator emits a speed starting from zero. The rotor winding of the twelve-phase AC synchronous generator is electrically connected to the second adjustable DC excitation power supply through a slip ring, and the voltage of the second adjustable DC excitation power supply can be continuously increased from 0, so that the twelve-phase AC synchronous generator emits a smooth and gradually increasing voltage starting from zero. The smooth and gradually increasing voltage and frequency starting from zero are supplied to the tested multi-phase synchronous generator to achieve its reliable and smooth starting, thereby achieving the purpose of reliable starting in a low-frequency and low-voltage manner. In this process, by controlling parameters such as given voltage and frequency, both reliable starting and accurate acquisition of test data are guaranteed.

[0006] A multi-phase synchronous generator test circuit started in an electric motor mode comprises a tested multi-phase synchronous generator, a first DC excitation power supply, a second DC excitation power supply, a twelve-phase synchronous generator, an asynchronous motor and a variable frequency power supply. The tested multi-phase synchronous generator is provided with an exciter. The second DC excitation power supply is electrically connected to the rotor winding of the twelve-phase synchronous generator through a slip ring on the non-driving end of the rotor of the twelve-phase synchronous generator. The rotating shaft of the twelve-phase synchronous generator is mechanically connected to the asynchronous motor through a coupling. The asynchronous motor is electrically connected to the variable frequency power supply. The stator winding voltage output end of the twelve-phase synchronous generator is connected to the stator winding voltage input end of the tested multi-phase synchronous generator. The first DC excitation power supply is electrically connected to the exciter provided on the multi-phase synchronous generator.

[0007] The first DC excitation power supply provides an excitation current for the exciter that is 0.9 times the rated no-load excitation current of the multi-phase synchronous generator; the multi-phase synchronous generator is a three-phase synchronous generator, or a six-phase synchronous generator, or a twelve-phase synchronous generator.

[0008] A test method for a multi-phase synchronous generator test circuit started by a motor comprises the following steps:

[0009] The first step is to set 3%-5% of the rated frequency of the tested multi-phase synchronous generator as the test starting frequency of the variable frequency power supply, set 6%-7% of the rated voltage value of the tested multi-phase synchronous generator as the test starting output voltage of the twelve-phase synchronous generator, and set 0.9 times the rated no-load excitation current of the multi-phase synchronous generator as the excitation current provided by the first DC excitation power supply to the exciter;

[0010] Step 2: According to the setting of the first step, provide excitation current for the exciter of the multi-phase synchronous generator; according to the setting of the first step, start the second DC excitation power supply; by adjusting the output voltage of the second DC excitation power supply, make the test starting output voltage of the twelve-phase synchronous generator reach 6%-7% of the rated voltage value of the tested multi-phase synchronous generator; start the asynchronous motor at low frequency, and at the same time, the twelve-phase synchronous generator provides low-voltage power for the multi-phase synchronous generator, and the multi-phase synchronous generator rotates slowly, so that the speed of the multi-phase synchronous generator reaches a stable state;

[0011] Step 3: Slowly increase the frequency of the variable frequency power supply, and set 20% of the rated frequency of the tested multi-phase synchronous generator as the test frequency of the variable frequency power supply. Under this test frequency, by adjusting the second DC excitation power supply, the twelve-phase synchronous generator provides the multi-phase synchronous generator with a power supply voltage of 20% of the rated voltage value of the tested multi-phase synchronous generator. During the speed increase process, the excitation current provided by the first DC excitation power supply to the exciter is adjusted to keep the power factor of the multi-phase synchronous generator above 0.8. Under this condition, collect the test parameters;

[0012] Step 4. Slowly increase the frequency of the variable frequency power supply, and set 40% of the rated frequency of the tested multi-phase synchronous generator as the test frequency of the variable frequency power supply. Under this test frequency, by adjusting the second DC excitation power supply, the twelve-phase synchronous generator provides the multi-phase synchronous generator with a power supply voltage of 40% of the rated voltage value of the tested multi-phase synchronous generator. During the speed-up process, the excitation current provided by the first DC excitation power supply to the exciter is adjusted to keep the power factor of the multi-phase synchronous generator above 0.8. Under this condition, collect the test parameters;

[0013] Step 5. Slowly increase the frequency of the variable frequency power supply, set 70% of the rated frequency of the tested multi-phase synchronous generator as the test frequency of the variable frequency power supply, and under this test frequency, adjust the second DC excitation power supply so that the twelve-phase synchronous generator provides the multi-phase synchronous generator with a power supply voltage of 70% of the rated voltage value of the tested multi-phase synchronous generator. During the speed-up process, adjust the excitation current provided by the first DC excitation power supply to the exciter so that the power factor of the multi-phase synchronous generator is maintained above 0.8, and collect the test parameters under this condition;

[0014] Step 6. Slowly increase the frequency of the variable frequency power supply, and set 100% of the rated frequency of the tested multi-phase synchronous generator as the test frequency of the variable frequency power supply. Under this test frequency, by adjusting the second DC excitation power supply, the twelve-phase synchronous generator provides the multi-phase synchronous generator with a power supply voltage of 100% of the rated voltage value of the tested multi-phase synchronous generator. During the speed-up process, the excitation current provided by the first DC excitation power supply to the exciter is adjusted to keep the power factor of the multi-phase synchronous generator above 0.8. Under this condition, the test parameters are collected.

[0015] The present invention reliably realizes the low-frequency and low-voltage starting of the multi-phase synchronous generator, has a small starting current, does not lose steps during the starting process, has a simple and standardized operating process, and has scientific and reasonable test data collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the test circuit of the present invention. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with the accompanying drawings:

[0018] A multi-phase synchronous generator test circuit started in an electric motor mode comprises a tested multi-phase synchronous generator 1, a first DC excitation power supply 3, a second DC excitation power supply 4, a twelve-phase synchronous generator 5, an asynchronous motor 6 and a variable frequency power supply 7. The tested multi-phase synchronous generator 1 is provided with an exciter 2, the second DC excitation power supply 4 is electrically connected to the rotor winding of the twelve-phase synchronous generator 5 through a slip ring 8 on the non-driving end of the rotor of the twelve-phase synchronous generator 5, the rotating shaft of the twelve-phase synchronous generator 5 is mechanically connected to the asynchronous motor 6 through a coupling 9, the asynchronous motor 6 is electrically connected to the variable frequency power supply 7, the stator winding voltage output end of the twelve-phase synchronous generator 5 is connected to the stator winding voltage input end of the tested multi-phase synchronous generator 1, and the first DC excitation power supply 3 is electrically connected to the exciter 2 provided on the multi-phase synchronous generator 1.

[0019] The first DC excitation power supply 3 provides the excitation current of the exciter 2 with 0.9 times the rated no-load excitation current of the multi-phase synchronous generator 1; the multi-phase synchronous generator 1 is a three-phase synchronous generator, or a six-phase synchronous generator, or a twelve-phase synchronous generator.

[0020] A test method for a multi-phase synchronous generator test circuit started by a motor comprises the following steps:

[0021] The first step is to set 3%-5% of the rated frequency of the tested multi-phase synchronous generator 1 as the test starting frequency of the variable frequency power supply 7, set 6%-7% of the rated voltage value of the tested multi-phase synchronous generator 1 as the test starting output voltage of the twelve-phase synchronous generator 5, and set 0.9 times the rated no-load excitation current of the multi-phase synchronous generator 1 as the excitation current provided by the first DC excitation power supply 3 to the exciter 2;

[0022] Step 2: According to the setting of the first step, provide excitation current for the exciter 2 of the multi-phase synchronous generator 1; according to the setting of the first step, start the second DC excitation power supply 4; by adjusting the output voltage of the second DC excitation power supply 4, the test start output voltage of the twelve-phase synchronous generator 5 reaches 6%-7% of the rated voltage value of the tested multi-phase synchronous generator 1; start the asynchronous motor 6 at a low frequency, and at the same time, the twelve-phase synchronous generator 5 provides a low-voltage power supply for the multi-phase synchronous generator 1, and the multi-phase synchronous generator 1 rotates slowly, so that the speed of the multi-phase synchronous generator 1 reaches a stable state;

[0023] Step 3: Slowly increase the frequency of the variable frequency power supply 7, set 20% of the rated frequency of the tested multi-phase synchronous generator 1 as the test frequency of the variable frequency power supply 7, under the test frequency, adjust the second DC excitation power supply 4, so that the twelve-phase synchronous generator 5 provides the multi-phase synchronous generator 1 with a power supply voltage of 20% of the rated voltage value of the tested multi-phase synchronous generator 1, and adjust the excitation current provided by the first DC excitation power supply 3 to the exciter 2 during the speed increase process, so that the power factor of the multi-phase synchronous generator 1 is maintained above 0.8, and collect the test parameters under this condition;

[0024] Step 4: Slowly increase the frequency of the variable frequency power supply 7, set 40% of the rated frequency of the tested multi-phase synchronous generator 1 as the test frequency of the variable frequency power supply 7, under the test frequency, adjust the second DC excitation power supply 4, so that the twelve-phase synchronous generator 5 provides the multi-phase synchronous generator 1 with a power supply voltage of 40% of the rated voltage value of the tested multi-phase synchronous generator 1, and adjust the excitation current provided by the first DC excitation power supply 3 to the exciter 2 during the speed increase process, so that the power factor of the multi-phase synchronous generator 1 is maintained above 0.8, and collect the test parameters under this condition;

[0025] Step 5: Slowly increase the frequency of the variable frequency power supply 7, set 70% of the rated frequency of the tested multi-phase synchronous generator 1 as the test frequency of the variable frequency power supply 7, under the test frequency, adjust the second DC excitation power supply 4 so that the twelve-phase synchronous generator 5 provides the multi-phase synchronous generator 1 with a power supply voltage of 70% of the rated voltage value of the tested multi-phase synchronous generator 1, and adjust the excitation current provided by the first DC excitation power supply 3 to the exciter 2 during the speed increase process so that the power factor of the multi-phase synchronous generator 1 is maintained above 0.8, and collect the test parameters under this condition;

[0026] Step 6. Slowly increase the frequency of the variable frequency power supply 7, and set 100% of the rated frequency of the tested multi-phase synchronous generator 1 as the test frequency of the variable frequency power supply 7. Under this test frequency, by adjusting the second DC excitation power supply 4, the twelve-phase synchronous generator 5 provides the multi-phase synchronous generator 1 with a power supply voltage of 100% of the rated voltage value of the tested multi-phase synchronous generator 1. During the speed-up process, the excitation current provided by the first DC excitation power supply 3 to the exciter 2 is adjusted to keep the power factor of the multi-phase synchronous generator 1 above 0.8. Under this condition, the test parameters are collected.

Claims

1. A test method for a multi-phase synchronous generator test circuit started by an electric motor, the test method being carried out by the multi-phase synchronous generator test circuit started by an electric motor, the multi-phase synchronous generator test circuit started by an electric motor comprising a multi-phase synchronous generator to be tested (1), a first DC excitation power supply (3), a second DC excitation power supply (4), a twelve-phase synchronous generator (5), an asynchronous motor (6) and a variable frequency power supply (7), the multi-phase synchronous generator to be tested (1) being provided with an exciter (2), the second DC excitation power supply (4) being electrically connected to a rotor winding of the twelve-phase synchronous generator (5) through a slip ring (8) on a non-driving end of a rotor of the twelve-phase synchronous generator (5), the twelve-phase synchronous generator (5) being electrically connected to a rotor winding of the twelve-phase synchronous generator (5), and the first DC excitation power supply (3), a second DC excitation power supply (4), a twelve-phase synchronous generator (5), an asynchronous motor (6) and a variable frequency power supply (7), the second DC excitation power supply (4) being electrically connected to a rotor winding of the twelve-phase synchronous generator (5) through a slip ring (8) on a non-driving end of a rotor of the twelve-phase synchronous generator (5). The rotating shaft of the generator (5) is mechanically connected to the asynchronous motor (6) through a coupling (9), the asynchronous motor (6) is electrically connected to the variable frequency power supply (7), the stator winding voltage output end of the twelve-phase synchronous generator (5) is connected to the stator winding voltage input end of the tested multi-phase synchronous generator (1), and the first DC excitation power supply (3) is electrically connected to the exciter (2) provided on the multi-phase synchronous generator (1); the excitation current provided by the first DC excitation power supply (3) to the exciter (2) is 0.9 times the rated no-load excitation current of the multi-phase synchronous generator (1); the multi-phase synchronous generator (1) is a three-phase synchronous generator, or a six-phase synchronous generator, or a twelve-phase synchronous generator; Its characteristics include the following steps: The first step is to set 3%-5% of the rated frequency of the tested multi-phase synchronous generator (1) as the test starting frequency of the variable frequency power supply (7), set 6%-7% of the rated voltage value of the tested multi-phase synchronous generator (1) as the test starting output voltage of the twelve-phase synchronous generator (5), and set 0.9 times the rated no-load excitation current of the multi-phase synchronous generator (1) as the excitation current provided by the first DC excitation power supply (3) to the exciter (2); Step 2: According to the setting of the first step, an excitation current is provided to the exciter (2) of the multi-phase synchronous generator (1); according to the setting of the first step, the second DC excitation power supply (4) is started; by adjusting the output voltage of the second DC excitation power supply (4), the test starting output voltage of the twelve-phase synchronous generator (5) reaches 6%-7% of the rated voltage value of the tested multi-phase synchronous generator (1); the asynchronous motor (6) is started at a low frequency, and at the same time, the twelve-phase synchronous generator (5) provides a low-voltage power supply to the multi-phase synchronous generator (1), and the multi-phase synchronous generator (1) rotates slowly, so that the speed of the multi-phase synchronous generator (1) reaches a stable state; Step 3: slowly increase the frequency of the variable frequency power supply (7), and set 20% of the rated frequency of the tested multi-phase synchronous generator (1) as the test frequency of the variable frequency power supply (7). Under the test frequency, the second DC excitation power supply (4) is adjusted so that the twelve-phase synchronous generator (5) provides the multi-phase synchronous generator (1) with a power supply voltage that is 20% of the rated voltage of the tested multi-phase synchronous generator (1). During the speed increase process, the excitation current provided by the first DC excitation power supply (3) to the exciter (2) is adjusted so that the power factor of the multi-phase synchronous generator (1) is maintained above 0.

8. Under this condition, the test parameters are collected; Step 4: slowly increase the frequency of the variable frequency power supply (7), and set 40% of the rated frequency of the tested multi-phase synchronous generator (1) as the test frequency of the variable frequency power supply (7). Under the test frequency, the second DC excitation power supply (4) is adjusted so that the twelve-phase synchronous generator (5) provides the multi-phase synchronous generator (1) with a power supply voltage that is 40% of the rated voltage value of the tested multi-phase synchronous generator (1). During the speed increase process, the excitation current provided by the first DC excitation power supply (3) to the exciter (2) is adjusted so that the power factor of the multi-phase synchronous generator (1) is maintained above 0.

8. Under this condition, the test parameters are collected; Step 5: Slowly increase the frequency of the variable frequency power supply (7), set 70% of the rated frequency of the tested multi-phase synchronous generator (1) as the test frequency of the variable frequency power supply (7), and at this test frequency, adjust the second DC excitation power supply (4) so ​​that the twelve-phase synchronous generator (5) provides the multi-phase synchronous generator (1) with a power supply voltage that is 70% of the rated voltage value of the tested multi-phase synchronous generator (1), and adjust the excitation current provided by the first DC excitation power supply (3) to the exciter (2) during the speed increase process so that the power factor of the multi-phase synchronous generator (1) is maintained above 0.8, and collect the test parameters under this condition; Step 6: Slowly increase the frequency of the variable frequency power supply (7), and set 100% of the rated frequency of the tested multi-phase synchronous generator (1) as the test frequency of the variable frequency power supply (7). Under the test frequency, by adjusting the second DC excitation power supply (4), the twelve-phase synchronous generator (5) provides the multi-phase synchronous generator (1) with a power supply voltage of 100% of the rated voltage value of the tested multi-phase synchronous generator (1). During the speed increase process, the excitation current provided by the first DC excitation power supply (3) to the exciter (2) is adjusted to keep the power factor of the multi-phase synchronous generator (1) above 0.

8. Under this condition, the test parameters are collected.

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