Adjustable power supply for synchronous motor synchronous machine start-stop test

Abstract

The utility model discloses a kind of adjustable power supply for synchronous motor synchronous machine start-stop test, and the adjustable power supply includes main circuit and control circuit;Main circuit includes single-phase ac power supply, power switch, power indicator, voltage regulator, first and second current transformers, voltmeter, first and second ammeter, current regulator and overcurrent relay, for adjusting and monitoring the voltage and current of output;Control circuit includes main relay, closing and opening button, normally open zero position switch, closing indicator, fault relay, reset button, fault indicator and fault buzzer, for according to the voltage and current of monitoring control the opening and closing of main circuit.This adjustable power supply overcomes the defect of traditional test operation, integrates external voltage regulation and current regulation part in one, convenient to carry, reduce field wiring amount, eliminate wiring error, improve test operation efficiency, effectively solve the problem of uncontrollable voltage and current monitoring in test process.

Description

Technical Field

[0001] This utility model relates to the field of motor testing technology, and in particular to an adjustable power supply for synchronous motor start-stop testing. Background Technology

[0002] In a certain type of small and medium-sized synchronous motor, the rotor contains thyristors for starting and stopping the synchronous motor, as well as a triggering module (ignition device) to trigger the thyristors. To ensure that the synchronous motor can start and stop normally, the start-stop circuit needs to be tested and inspected.

[0003] During the test, the rectifier circuit in the rotor must be completely disconnected from the three-phase coils (i.e., the power supply part of the rotating commutator) of the exciter rotor and the main motor excitation coils (i.e., the power receiving part of the rotating commutator) in the rotor. Then, the AC adjustable power supply, the variable resistor for current limiting and the oscilloscope are connected to the rectifier circuit to conduct the start-stop circuit test.

[0004] During actual testing, the external AC adjustable power supply exhibited the following problems: 1) The test devices are scattered and independent, making them inconvenient to move and requiring multiple people to handle them.

[0005] 2) On-site wiring is labor-intensive, inefficient, and prone to incorrect wiring.

[0006] 3) On-site testing lacks overcurrent and overvoltage protection, requiring dedicated personnel to monitor voltage and current and be ready to cut off the power supply at any time. This results in low testing efficiency and certain safety risks. Summary of the Invention

[0007] The technical problem to be solved by this utility model is to provide an adjustable power supply for the start-stop test of synchronous motor. This adjustable power supply overcomes the defects of traditional test operations, integrates external voltage regulation and current regulation into one unit, is easy to transport, reduces the amount of on-site wiring, eliminates wiring errors, improves the efficiency of test operations, and effectively solves the problem of uncontrollable voltage and current monitoring during the test process.

[0008] To solve the above-mentioned technical problems, the adjustable power supply for the start-stop test of the synchronous motor of this utility model includes a main circuit and a control circuit. The main circuit includes a single-phase AC power supply, a power switch, a power indicator light, a voltage regulator, a first current transformer, a second current transformer, a voltmeter, a first ammeter, a second ammeter, a current regulator, and an overcurrent relay with a normally open contact. The power switch is connected in series with the first normally open contact of the main relay and is located between the single-phase AC power supply and the voltage regulator. The power indicator light is connected to the output terminal of the power switch. The voltmeter is connected to the output terminal of the voltage regulator. The first and second current transformers are located on the output neutral line of the voltage regulator. The coils of the first ammeter and the overcurrent relay are connected in series with the output terminal of the first current transformer. The second ammeter is connected in series with the output terminal of the second current transformer. The current regulator is connected in series with the output neutral line of the voltage regulator. The voltmeter outputs an overvoltage switch signal. The first ammeter outputs a high-current overcurrent switch signal. The second ammeter outputs a low-current overcurrent switch signal. The output terminal of the voltage regulator is an adjustable power supply output terminal. The control circuit includes a main relay with a first normally open contact and a second normally open contact, a closing button, a tripping button, a normally open zero-position switch, a closing indicator light, a fault relay with normally closed contacts and normally open contacts, a reset button, a fault indicator light, and a fault buzzer. The normally open zero-position switch, the closing button, the tripping button, the normally closed contact of the fault relay, and the main relay coil are connected in series and then connected to the output terminal of the power switch. The second normally open contact of the main relay is connected in parallel across the normally open zero-position switch and the closing button. The closing indicator light is connected in parallel across the main relay coil. The normally open contact of the overcurrent relay, the normally open contact of the fault relay, the overvoltage switch signal, the high current overcurrent switch signal, and the low current overcurrent switch signal are connected in parallel and then connected in series across the reset button and the fault relay coil, with both ends connected to the output terminal of the power switch. The fault indicator light and the fault buzzer are connected in parallel across the fault relay coil.

[0009] Furthermore, this adjustable power supply also includes a first cooling fan and a second cooling fan, which are respectively connected to the output terminal of the power switch and provide forced air cooling to the main circuit and the control circuit respectively.

[0010] Furthermore, the neutral wire output by the voltage regulator is provided with a floating terminal between the first current transformer and the second current transformer and at the neutral wire output end, and is connected by a shorting wire.

[0011] Furthermore, the output end of the voltage regulator is provided with two sets of external terminals.

[0012] Furthermore, this adjustable power supply also includes a housing, with the main circuit and control circuit located inside the housing. A single-phase AC power socket, power switch, power indicator light, voltage regulator, voltmeter, first ammeter, second ammeter, current regulator, closing button, opening button, closing indicator light, reset button, fault indicator light, fault buzzer, and two sets of external terminals are respectively located on the housing panel.

[0013] Furthermore, the enclosure includes an outer shell and a mounting frame that is inserted into the outer shell. The main circuit and the control circuit are located within the mounting frame. The enclosure panel is located on the top surface of the mounting frame. The first cooling fan and the second cooling fan are respectively located on the side wall of the outer shell.

[0014] Because this adjustable power supply for synchronous motor start-stop testing adopts the above-mentioned technical solution, namely, the adjustable power supply includes a main circuit and a control circuit; the main circuit includes a single-phase AC power supply, a power switch, a power indicator light, a voltage regulator, first and second current transformers, a voltmeter, first and second ammeters, a current regulator, and an overcurrent relay, used to regulate and monitor the output voltage and current; the control circuit includes a main relay, closing and opening buttons, a normally open zero-position switch, a closing indicator light, a fault relay, a reset button, a fault indicator light, and a fault buzzer, used to control the opening and closing of the main circuit according to the monitored voltage and current. This adjustable power supply overcomes the defects of traditional testing operations, integrating external voltage and current regulation into one unit, facilitating transportation, reducing on-site wiring, eliminating wiring errors, improving testing efficiency, and effectively solving the problem of uncontrollable voltage and current monitoring during the testing process. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the main circuit of the adjustable power supply of this utility model; Figure 2 This is a schematic diagram of the control circuit of the adjustable power supply of this utility model; Figure 3 This is a schematic diagram of the cabinet panel layout of the adjustable power supply of this utility model. Figure 4 This is a schematic diagram of the housing of the adjustable power supply of this utility model; Figure 5 This is a schematic diagram illustrating the application of the adjustable power supply of this utility model. Detailed Implementation

[0016] Implementation, for example Figure 1 and Figure 2 As shown, the adjustable power supply for the start-stop test of a synchronous motor includes a main circuit and a control circuit. The main circuit includes a single-phase AC power supply D, a power switch Q, a power indicator light H1, a voltage regulator T, a first current transformer CT1, a second current transformer CT2, a voltmeter V, a first ammeter A1, a second ammeter A2, a current regulator R, and an overcurrent relay KA with a normally open contact KA1. The power switch Q is connected in series with the first normally open contact K1 of the main relay K and is located between the single-phase AC power supply D and the voltage regulator T. The power indicator light H1 is connected to the output terminal of the power switch Q, and the voltmeter V is connected to the output terminal of the voltage regulator T. The first current transformer CT1 and the second current transformer CT2 are connected in series with the main current transformer T. Two current transformers CT2 are connected to the output neutral line of the voltage regulator T. The first ammeter A1 and the overcurrent relay KA coil are connected in series to the output terminal of the first current transformer CT1. The second ammeter A2 is connected in series to the output terminal of the second current transformer CT2. The current regulator R is connected in series to the output neutral line of the voltage regulator T. The voltmeter V outputs an overvoltage switch signal V1. The first ammeter A1 outputs a large current overcurrent switch signal A11. The second ammeter A2 outputs a small current overcurrent switch signal A21. The output terminal of the voltage regulator T is an adjustable power supply output terminal. The control circuit includes a main relay K with a first normally open contact K1 and a second normally open contact K2, a closing button SB1, a tripping button SB2, a normally open zero-position switch SL, a closing indicator light H2, a fault relay J with a normally closed contact J1 and a normally open contact J2, a reset button SB3, a fault indicator light H3, and a fault buzzer H4. The normally open zero-position switch SL, the closing button SB1, the tripping button SB2, the normally closed contact J1 of the fault relay J, and the coil of the main relay K are connected in series and then connected to the output terminal of the power switch Q. The second normally open contact of the main relay K... Point K2 is connected in parallel to the normally open zero-position switch SL and the closing button SB1. The closing indicator light H2 is connected in parallel to the coil of the main relay K. The normally open contact KA1 of the overcurrent relay KA, the normally open contact J2 of the fault relay J, the overvoltage switch signal V1, the high current overcurrent switch signal A11, and the low current overcurrent switch signal A21 are connected in parallel and then connected in series with the reset button SB3 and the coil of the fault relay J. The two ends are connected to the output terminal of the power switch Q. The fault indicator light H3 and the fault buzzer H4 are connected in parallel to the coil of the fault relay J.

[0017] Preferably, the adjustable power supply further includes a first cooling fan M1 and a second cooling fan M2, which are respectively connected to the output terminal of the power switch Q and provide forced air cooling for the main circuit and the control circuit respectively.

[0018] Preferably, the output neutral wire of the voltage regulator T is provided with floating terminals R1 and R2 between the first current transformer CT1 and the second current transformer CT2 and at the neutral wire output end, and is connected by a shorting wire R3.

[0019] Preferably, the output terminal of the voltage regulator T is provided with two sets of external terminals a1 / x1 and a2 / x2.

[0020] Preferred, such as Figure 3 As shown, this adjustable power supply also includes a housing B. The main circuit and control circuit are located inside the housing B. The single-phase AC power socket D1, power switch Q, power indicator H1, voltage regulator T, voltmeter V, first ammeter A1, second ammeter A2, current regulator R, closing button SB1, opening button SB2, closing indicator H2, reset button SB3, fault indicator H3, fault buzzer H4, and two sets of external terminals a1 / x1 and a2 / x2 are respectively located on the housing panel B1.

[0021] Preferred, such as Figure 4 As shown, the housing B includes a housing shell B2 and a mounting frame B3 that is inserted into the housing shell B2. The main circuit and the control circuit are located in the mounting frame B3. The housing panel B1 is located on the top surface of the mounting frame B3. The first cooling fan M1 and the second cooling fan M2 are respectively located on the side wall of the housing shell B2.

[0022] This adjustable power supply features an integrated design, housing all components within a single enclosure for convenient and easy transport and operation. Forced air cooling via two fans ensures stable operation over extended periods.

[0023] This adjustable power supply connects to a single-phase AC power supply D via a single-phase AC220V / 50Hz socket D1, and externally connects to the required power supply equipment via two sets of parallel ports a1, x1 and a2, x2. All operations, including switching the single-phase AC power supply D on and off; switching the output voltage; adjusting the output voltage and current; automatic disconnection and reset in case of fault; and external circuit expansion functions via expansion ports R1 and R2, are integrated on the enclosure panel B1, ensuring convenience, reliability, and safety during use.

[0024] When the power switch Q is in the off state, the adjustable power supply is in cold standby mode, and the main circuit is not energized. When the power switch Q is closed, the power indicator light H1 stays on, and the two cooling fans start running immediately upon power-up. Adjust the voltage regulator T to zero, and the normally open zero-position switch SL closes (before each closing operation, the voltage regulator must be checked to return to the zero position so that the normally open zero-position switch SL closes). At this time, press the normally open closing button SB1. The main relay K coil is energized, the normally open contact K1 closes, the main circuit is energized, the normally open contact K2 closes for self-locking, and the closing indicator light H2 stays on. If only the power indicator light H1 and the closing indicator light H2 are on at this time, it indicates that the circuit is normal and in hot standby mode, and the adjustable power supply can be put into use. When the normally closed trip button SB2 is pressed, or a fault signal is generated, the normally closed contact J1 of the fault relay J opens, causing the main relay K coil to de-energize, the normally open contact K1 to open and de-energize the main circuit, the normally open contact K2 to open, and the self-locking is released.

[0025] In the fault circuit, the generation of any fault signal—namely, the closure of any normally open contact among the overvoltage switch signal V1, the high-current overcurrent switch signal A11, the low-current overcurrent switch signal A21, and the overcurrent relay KA's energizing output signal (KA1)—will cause the fault relay J coil to energize, its normally open contact J2 to close, the circuit to self-lock, the fault indicator H3 to remain illuminated, and the fault buzzer H4 to sound continuously. The normally open contact J1 of the fault relay J will then open, cutting off the closing circuit. Although the main circuit is de-energized at this time, and the fault signal will disappear, the fault indication will only disappear when the normally closed reset button SB3 is pressed. At this point, the fault should be checked and rectified before the next energization can be performed.

[0026] like Figure 5 As shown, in practical applications, the external terminals a1 / x1 of this adjustable power supply are connected to an oscilloscope, and a2 / x2 are connected to the thyristor E of the motor under test. When the main relay K coil is energized and the normally open contact K1 is closed, the voltage regulator T can adjust the output voltage. The output voltage is displayed and monitored in real time by the voltmeter V. When the output voltage is greater than 250V, the voltmeter V will generate an overvoltage switch signal V1, which energizes the fault relay J coil and simultaneously disconnects the closing circuit through its normally closed contact J1, thereby disconnecting the main circuit and triggering a fault alarm until the normally closed reset button SB3 is pressed.

[0027] The main circuit has floating terminals R1 and R2, which are usually left floating. In this case, the main circuit's current is limited by the second current transformer CT2 (i.e., current is monitored by the second ammeter A2, with a maximum setting of 500mA). When the current exceeds the limit, the small overcurrent switch signal A21 will activate the fault circuit and disconnect the closing circuit and the main circuit. When the thyristor E of the tested motor requires a larger current, R1 and R2 can be shorted using the shorting wire R3. In this case, the main circuit is monitored by the first ammeter A1 in the first current transformer CT1 circuit, and the maximum main circuit current is set to 4A. When the current exceeds the limit, the large overcurrent switch signal A11 will activate the fault circuit and disconnect the closing circuit and the main circuit.

[0028] Since the switching signals of voltmeter V and ammeters A1 and A2 are not normally open contacts in the physical sense, in order to ensure safety, an overcurrent relay KA is connected in series in the first current transformer CT1, with a set value of 4A, to form a double protection with the first ammeter A1.

[0029] The specific experimental procedure is as follows: 1. Close the power switch Q, the power indicator light H1 will light up, the voltage and current meters will complete initialization, and the two cooling fans will start running. At this time, the switch can be adjusted from cold standby to hot standby. 2. Check and adjust the voltage regulator to zero (i.e., the normally open zero-position switch SL must be in the zero position), press the closing button SB1, the main contactor K closes, the closing indicator light H2 lights up, and the voltage and current can be adjusted. 3. Adjust the voltage regulator and current regulator as required, adjust the current and voltage until the oscilloscope records an accurate waveform, adjust the voltage to zero, press the trip button SB2, the closing indicator H2 will go out, and the test is over.

[0030] The AC output of this adjustable power supply is a sinusoidal AC wave, free from harmonic effects. It eliminates the need to consider factors such as harmonic suppression, interference, and waveform distortion. It is more economical and practical than power supplies that utilize analog-digital control, electronic regulation, or inverter technology. The generated waveform is more suitable for testing and experimentation where waveform requirements are specific, including but not limited to synchronous motor rotor start-stop modules.

[0031] The voltage regulator uses a 1KVA, 250V / 4A AC single-phase regulator, leaving sufficient capacity margin for test expansion. This adjustable power supply is suitable for most test environments, especially when temporary non-standard voltages are required on-site.

[0032] The voltmeter and ammeter in this adjustable power supply are digital display instruments, which facilitates monitoring and setting of voltage and current limiting functions. When the current or voltage reaches the set value, an alarm is immediately triggered and the main circuit is cut off to ensure the safety of the test.

[0033] Two sets of external terminals are provided, allowing the oscilloscope to sample directly from the output point, thus shielding the field environment and making wiring more flexible and convenient. Floating terminals are provided at both ends of the current regulator, allowing for the output of larger currents by connecting shorting wires, expanding output power and adding more functionalities.

[0034] Market research indicates that most adjustable power supplies typically employ IGBT / PWM technology, controlled via a DSP platform, and utilize impedance simulation or harmonic injection modules for current control. These power supplies exhibit waveform hysteresis and distortion during response, leading to deviations in data collected from repeated testing. Conversely, purely resistive current regulation methods are bulky, inconvenient to transport, and expensive.

[0035] This adjustable power supply is primarily used for testing the rotor start-stop device of a synchronous motor. The power requirements are linearly adjustable voltage and controllable current. Each test requires 3 to 5 repeated power supply cycles, each lasting approximately 10 to 20 minutes. These tests typically follow long-cycle repairs of the synchronous motor, hence their low usage frequency. Considering the rapid response required by the rotor start-stop device, an autotransformer is used to regulate the output voltage, and a purely resistive load is used to refine the current regulation, enabling rapid and accurate acquisition of test waveform data. Manual adjustment replaces automatic closed-loop control using various electronic components, significantly reducing costs. Given the relatively low usage of this adjustable power supply in this type of testing, and the forced cooling by two fans, the power supply stability is highly guaranteed.

Claims

1. An adjustable power supply for starting and stopping tests of synchronous motors, characterized in that: Includes the main circuit and the control circuit; The main circuit includes a single-phase AC power supply, a power switch, a power indicator light, a voltage regulator, a first current transformer, a second current transformer, a voltmeter, a first ammeter, a second ammeter, a current regulator, and an overcurrent relay with a normally open contact. The power switch is connected in series with the first normally open contact of the main relay and is located between the single-phase AC power supply and the voltage regulator. The power indicator light is connected to the output terminal of the power switch. The voltmeter is connected to the output terminal of the voltage regulator. The first and second current transformers are located on the output neutral line of the voltage regulator. The coils of the first ammeter and the overcurrent relay are connected in series with the output terminal of the first current transformer. The second ammeter is connected in series with the output terminal of the second current transformer. The current regulator is connected in series with the output neutral line of the voltage regulator. The voltmeter outputs an overvoltage switch signal. The first ammeter outputs a high-current overcurrent switch signal. The second ammeter outputs a low-current overcurrent switch signal. The output terminal of the voltage regulator is an adjustable power supply output terminal. The control circuit includes a main relay with a first normally open contact and a second normally open contact, a closing button, a tripping button, a normally open zero-position switch, a closing indicator light, a fault relay with normally closed contacts and normally open contacts, a reset button, a fault indicator light, and a fault buzzer. The normally open zero-position switch, the closing button, the tripping button, the normally closed contact of the fault relay, and the main relay coil are connected in series and then connected to the output terminal of the power switch. The second normally open contact of the main relay is connected in parallel across the normally open zero-position switch and the closing button. The closing indicator light is connected in parallel across the main relay coil. The normally open contact of the overcurrent relay, the normally open contact of the fault relay, the overvoltage switch signal, the high current overcurrent switch signal, and the low current overcurrent switch signal are connected in parallel and then connected in series across the reset button and the fault relay coil, with both ends connected to the output terminal of the power switch. The fault indicator light and the fault buzzer are connected in parallel across the fault relay coil.

2. The adjustable power supply for synchronous motor start-stop testing according to claim 1, characterized in that: It also includes a first cooling fan and a second cooling fan, which are respectively connected to the output terminal of the power switch and provide forced air cooling to the main circuit and the control circuit respectively.

3. The adjustable power supply for synchronous motor start-stop testing according to claim 1 or 2, characterized in that: The neutral wire output of the voltage regulator is provided with a floating terminal between the first current transformer and the second current transformer and at the neutral wire output end, and is connected by a short wire.

4. The adjustable power supply for synchronous motor start-stop testing according to claim 3, characterized in that: The output end of the voltage regulator is equipped with two sets of external terminals.

5. The adjustable power supply for synchronous motor start-stop testing according to claim 4, characterized in that: It also includes a housing, in which the main circuit and control circuit are located. A single-phase AC power socket, power switch, power indicator light, voltage regulator, voltmeter, first ammeter, second ammeter, current regulator, closing button, opening button, closing indicator light, reset button, fault indicator light, fault buzzer, and two sets of external terminals are respectively located on the housing panel.

6. The adjustable power supply for synchronous motor start-stop testing according to claim 5, characterized in that: The enclosure includes an outer shell and a mounting frame that is inserted into the outer shell. The main circuit and control circuit are located within the mounting frame. The enclosure panel is located on the top surface of the mounting frame. The first cooling fan and the second cooling fan are respectively located on the side wall of the outer shell.

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