Circuit for avoiding breakdown of synchronous motor thyristor of coke-oven gas compressor

Abstract

According to the circuit for avoiding breakdown of the synchronous motor thyristor of the coke-oven gas compressor, the resistance-capacitance circuit is arranged on the rectifier of the synchronous motor; the rectifier bridge comprises three phases of branches, each phase of branch comprises a thyristor and a diode which are connected in series, specifically, the thyristor K1 and the diode G2 in the A-phase branch are connected in series, the thyristor K3 and the diode G4 in the B-phase branch are connected in series, and the thyristor K5 and the diode G6 in the C-phase branch are connected in series. The midpoint of a branch circuit where the thyristor K1 and the diode G2 are connected in series is connected with the A phase of the coaxial power generation rotor of the alternating-current exciter, the midpoint of a branch circuit where the thyristor K3 and the diode G4 are connected in series is connected with the B phase of the coaxial power generation rotor of the alternating-current exciter, and the midpoint of a branch circuit where the thyristor K5 and the diode G6 are connected in series is connected with the C phase of the coaxial power generation rotor of the alternating-current exciter. The technology can effectively prevent a synchronous motor thyristor from breaking down a rectifier to be burnt out and prevent a unit from being shut down, thereby avoiding non-planned shutdown of the ammonia synthesis device due to motor jump stop.

Description

Technical Field

[0001] The utility model belongs to the technical field of circuits and relates to a circuit for preventing the thyristors of a synchronous motor of a coke oven gas compressor from being broken down. Background Art

[0002] Since the ammonia synthesis plant was put into use, the synchronous motor of the coke oven gas compressor has stopped running 12 times due to the breakdown of thyristors and the burning out of rectifiers, 2 times due to the burning out of the field discharge resistors, and 1 time due to the burning out of the stator coils, resulting in the shutdown and production reduction of the ammonia synthesis plant. Each time, the normal production of the ammonia synthesis plant was affected for 8 - 12 hours, and the maintenance cost was more than a hundred thousand yuan. Although measures such as strengthening personnel inspection and supervision have been taken, the fundamental problem of the breakdown of thyristors and the burning out of rectifiers of the synchronous motor of the coke oven gas compressor cannot be solved fundamentally. Summary of the Invention

[0003] The utility model aims to make up for the deficiencies of the prior art and provides a circuit for preventing the thyristors of a synchronous motor of a coke oven gas compressor from being broken down. The problem to be solved is the breakdown of the thyristors of the synchronous motor.

[0004] The utility model is realized through the following technical solutions:

[0005] A circuit for preventing the thyristors of a synchronous motor of a coke oven gas compressor from being broken down, characterized in that a resistor - capacitor circuit is installed on the rectifier of the synchronous motor;

[0006] The rectifier bridge includes three - phase branches. Each phase branch includes a thyristor and a diode in series. Specifically, in the A - phase branch, the thyristor K1 and the diode G2 are in series. In the B - phase branch, the thyristor K3 and the diode G4 are in series. In the C - phase branch, the thyristor K5 and the diode G6 are in series. The mid - point of the branch where the thyristor K1 and the diode G2 are in series is connected to the A - phase of the co - axial generator rotor of the AC exciter. The mid - point of the branch where the thyristor K3 and the diode G4 are in series is connected to the B - phase of the co - axial generator rotor of the AC exciter. The mid - point of the branch where the thyristor K5 and the diode G6 are in series is connected to the C - phase of the co - axial generator rotor of the AC exciter.

[0007] A resistor - capacitor protection circuit is connected in parallel with the thyristor of each phase branch, and a resistor - capacitor protection circuit is also connected in parallel with the diode of each phase branch. In the A - phase, the two ends of the thyristor K1 are connected with a resistor R1 and a capacitor C1 in series, and the resistor R1 and the capacitor C1 form a resistor - capacitor protection circuit; the two ends of the diode G2 are connected with a resistor R2 and a capacitor C2 in series, and the resistor R2 and the capacitor C2 form a resistor - capacitor protection circuit;

[0008] In the B - phase, the two ends of the thyristor K3 are connected with a resistor R3 and a capacitor C3 in series, and the two ends of the diode G4 are connected with a resistor R4 and a capacitor C4 in series;

[0009] In phase C, a resistor R5 and a capacitor C5 connected in series are connected across the thyristor K5, and a resistor R6 and a capacitor C6 connected in series are connected across the diode G6.

[0010] Two sets of endpoints of the three-phase branch are respectively connected to both ends of the rotor excitation winding, and the stator winding is connected to a 10KV three-phase power supply.

[0011] The control electrode of each thyristor is connected to a control module device for driving the thyristor to operate.

[0012] In the present utility model, by adding a resistor-capacitor device to the rotating disc rectifier of the synchronous motor, the power supply system fluctuations generated during the starting process of the synchronous motor soft starter are induced into three-phase alternating current through the rotating disc, and then regulated into direct current by the rectifier to prevent the thyristor from being broken down due to the power grid fluctuations generated by the soft starter during the rectification process. Using the resistor-capacitor principle, the induced voltage generated by the rotation of the synchronous motor forms an induced current for rectification through the thyristor. Since the stator winding of the motor inevitably generates power grid fluctuations during starting, it may cause the thyristor or diode to be broken down, resulting in equipment shutdown. The resistor-capacitor device includes a resistor with a specific resistance value and a capacitor with a specific capacitance value calculated. The resistor and capacitor are connected in series, and the capacitor and resistor are connected in parallel with the thyristor and diode to absorb the fluctuations during the rectification process of the exciter, avoid the thyristor and diode from being broken down, so that the motor starts smoothly and operates safely, ensuring the continuous production of the ammonia synthesis plant.

[0013] The advantages of this technology are as follows: By absorbing technology with a resistor-capacitor device, the structure is simple and the installation is convenient. It effectively solves the problem of breakdown of thyristors and diodes in synchronous motors, ensures the smooth operation of synchronous motors, the continuous production of ammonia synthesis plants, reduces shutdown losses, and improves the production efficiency of ammonia synthesis products. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 , Schematic diagram of the circuit after the transformation of the rectifier of the synchronous motor of the coke oven gas compressor.

[0015] In the figure, K1, K3, and K5 are three thyristors; G2, G4, and G6 are three diodes; L1 and L2 are the rectified power supplies;

[0016] In the three dashed boxes, R1, R2, R3, R4, R5, and R6 are resistors, C1, C2, C3, C4, C5, and C6 are capacitors, and the resistors, capacitors, and connecting wires form a resistor-capacitor device circuit. DETAILED DESCRIPTION OF THE INVENTION

[0017] The attached drawing is an embodiment of the present utility model.

[0018] The circuit for preventing breakdown of the thyristor of the synchronous motor of the coke oven gas compressor in the present utility model installs a resistor-capacitor circuit on the rectifier of the synchronous motor;

[0019] The rectifier bridge includes three-phase branches, and each phase branch includes a thyristor and a diode connected in series. Specifically, in the A-phase branch, thyristor K1 and diode G2 are connected in series; in the B-phase branch, thyristor K3 and diode G4 are connected in series; in the C-phase branch, thyristor K5 and diode G6 are connected in series. The midpoint of the branch where thyristor K1 and diode G2 are connected in series is connected to the A-phase of the coaxial generator rotor of the AC exciter; the midpoint of the branch where thyristor K3 and diode G4 are connected in series is connected to the B-phase of the coaxial generator rotor of the AC exciter; the midpoint of the branch where thyristor K5 and diode G6 are connected in series is connected to the C-phase of the coaxial generator rotor of the AC exciter.

[0020] A resistive-capacitive protection circuit is connected in parallel with the thyristor of each phase branch, and a resistive-capacitive protection circuit is also connected in parallel with the diode of each phase branch. In the A-phase, a resistor R1 and a capacitor C1 connected in series are connected across the two ends of thyristor K1, and resistor R1 and capacitor C1 form a resistive-capacitive protection circuit; a resistor R2 and a capacitor C2 connected in series are connected across the two ends of diode G2, and resistor R2 and capacitor C2 form a resistive-capacitive protection circuit.

[0021] In the B-phase, a resistor R3 and a capacitor C3 connected in series are connected across the two ends of thyristor K3, and a resistor R4 and a capacitor C4 connected in series are connected across the two ends of diode G4.

[0022] In the C-phase, a resistor R5 and a capacitor C5 connected in series are connected across the two ends of thyristor K5, and a resistor R6 and a capacitor C6 connected in series are connected across the two ends of diode G6.

[0023] The two sets of endpoints of the three-phase branches are respectively connected to the two ends of the rotor excitation winding, and the stator winding is connected to a 10KV three-phase power supply; after rectification, the power supply powers the rotor coil, making the rotor form a permanent magnet.

[0024] The control electrode of each thyristor is connected to a control module device for driving the thyristor to work.

[0025] The coaxial generator rotor of the AC exciter, the rectifier bridge circuit, the resistive-capacitive protection circuit, and the rotor excitation winding are all installed on the rotor of the synchronous motor, and the stator winding is installed on the stator of the synchronous motor.

[0026] A resistive-capacitive device is installed inside the rotating disc rectifier device of the synchronous motor. The influence of the power grid startup fluctuation and the induced voltage fluctuation generated on the rotor of the synchronous motor are prevented from breaking down the thyristor and diode and causing electric shock injury and damaging the rectifier by the resistive-capacitive device connected in parallel with the rectifier device; the resistive-capacitive device has specific resistance values and capacitance values according to the actual needs of the rotating disc. It effectively protects the thyristor and diode and ensures the stable operation of the synchronous motor.

[0027] After the transformation, all electrical personnel will be trained, and the capacitive-resistive device will be regularly inspected.

[0028] After implementation, through the capacitive-resistive device absorption technology, it effectively solves the breakdown of thyristors and diodes during the use of the synchronous motor of the coke oven gas compressor, ensuring the continuous production of the ammonia synthesis plant; through this electrical technology, the thyristors of the synchronous motor were burned out three times a year due to breakdown, and it is solved to the normal use of thyristors and diodes for five years, improving product quality and output, meeting the requirements of normal production and maintenance, and reducing the production cost of ammonia synthesis.

[0029] After the transformation of the rectifier device, according to the on-site operation conditions, the operation effect proves that the technology is reliable and has obvious advantages.

Claims

1. A thyristor breakdown avoidance circuit for a synchronous motor of a coke oven gas compressor, characterized in that: Install a resistor-capacitor device circuit on the rectifier of the synchronous motor; The rectifier bridge includes three-phase branches. Each phase branch includes a thyristor and a diode in series. Specifically, in the A-phase branch, thyristor K1 and diode G2 are in series. In the B-phase branch, thyristor K3 and diode G4 are in series. In the C-phase branch, thyristor K5 and diode G6 are in series. The midpoint of the branch where thyristor K1 and diode G2 are in series is connected to the A-phase of the AC exciter coaxial generator rotor. The midpoint of the branch where thyristor K3 and diode G4 are in series is connected to the B-phase of the AC exciter coaxial generator rotor. The midpoint of the branch where thyristor K5 and diode G6 are in series is connected to the C-phase of the AC exciter coaxial generator rotor.

2. The thyristor breakdown avoidance circuit of the synchronous motor of the coke oven gas compressor according to claim 1, wherein: A resistor-capacitor protection circuit is connected in parallel with each thyristor in each phase branch, and a resistor-capacitor protection circuit is also connected in parallel with each diode in each phase branch. In the A-phase, a resistor R1 and a capacitor C1 connected in series are connected across the two ends of thyristor K1, and resistor R1 and capacitor C1 form the resistor-capacitor protection circuit; a resistor R2 and a capacitor C2 connected in series are connected across the two ends of diode G2, and resistor R2 and capacitor C2 form the resistor-capacitor protection circuit; In the B-phase, a resistor R3 and a capacitor C3 connected in series are connected across the two ends of thyristor K3, and a resistor R4 and a capacitor C4 connected in series are connected across the two ends of diode G4; In the C-phase, a resistor R5 and a capacitor C5 connected in series are connected across the two ends of thyristor K5, and a resistor R6 and a capacitor C6 connected in series are connected across the two ends of diode G6.

3. The thyristor breakdown avoidance circuit for the synchronous motor of the coke oven gas compressor according to claim 1, wherein: The two sets of endpoints of the three-phase branches are respectively connected to the two ends of the rotor excitation winding, and the stator winding is connected to the 10KV three-phase power supply.

4. The thyristor breakdown avoidance circuit for the synchronous motor of the coke oven gas compressor according to claim 1, characterized in that: The control electrode of each thyristor is connected to a control module device for driving the thyristor to work.

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