Mine underground drill jumbo power supply phase sequence automatic switching control system

Abstract

The utility model discloses a mine underground drill jumbo power supply phase sequence automatic switching control system which comprises a main circuit used for supplying power to a motor, and the main circuit further comprises a phase sequence relay, a contactor KM1, a contactor KM2, a contactor KM3 and a contactor KM4. The pressure sensor PS is mounted on a water outlet pipeline of the water supply system controlled by the motor. The control loop comprises a start button SB1, a stop button SB2, a relay KA1 and a time relay KT. According to the utility model, the current phase sequence is detected through the phase sequence relay, and if the phase sequence is wrong, the contactor is triggered to act, so that the connection relation between the power supply and the motor is automatically switched, and the reverse starting of the motor is avoided; when the phase sequence relay cannot work normally, forced power-off and alarm can be carried out in time, and the reliability of the system is improved.

Description

Technical Field

[0001] This utility model relates to a power conversion control system. Background Technology

[0002] Trackless drilling equipment used in underground mining operations operates for extended periods in a damp, high-chlorine-ion environment. This harsh environment severely restricts the reliability and stability of the electrical control systems of any equipment. Taking the DD311 rock drilling rig as an example, its water pump motor has a power of 4KW, uses a direct-start method, and operates at 380V. To ensure normal equipment operation, the phase sequence of the motor must be correct to guarantee the correct motor rotation direction.

[0003] In actual operation, phase sequence tests and adjustments are required every time power is connected. The distance from the operator's cab to the cable connection point is 80-100 meters, which not only severely impacts work efficiency but also increases the workload of workers. Furthermore, the phase sequence indicator lights underground frequently malfunction, making it impossible for operators to accurately determine the correct phase sequence. If the phase sequence is incorrect, the motor will rotate in reverse, causing the water supply system to circulate in reverse, leading to accidents and significant economic losses. Utility Model Content

[0004] This utility model proposes an automatic phase sequence switching control system for the power supply of underground drilling rigs in mines. Its purpose is to solve the problems of phase sequence adjustment affecting work efficiency and phase sequence errors causing accidents.

[0005] The technical solution of this utility model is as follows:

[0006] An automatic phase sequence switching control system for power supply of a rock drilling rig in a mine includes a main circuit for powering the motor. In the main circuit, the three-phase power supply is connected to the motor in sequence through a main switch Q100 and a circuit breaker 1F100. The main circuit also includes a phase sequence relay, contactor KM1, contactor KM2, contactor KM3 and contactor KM4.

[0007] The three-phase power supply is connected to a phase sequence relay, which has normally open and normally closed contacts that operate synchronously according to the phase sequence of the power supply. The normally open contacts of the phase sequence relay are connected in series with the coil of contactor KM2 to form a reverse sequence first control branch, and the normally closed contacts of the phase sequence relay are connected in series with the coil of contactor KM1 to form a positive sequence first control branch. The reverse sequence first control branch and the positive sequence first control branch are connected in parallel between two phases of the three-phase power supply.

[0008] The normally open contact of contactor KM3 is connected in parallel with the normally open contact of contactor KM4. The normally open contact of contactor KM3 is used to realize the positive sequence connection between the three-phase power supply and the motor, and the normally open contact of contactor KM4 is used to realize the reverse sequence connection between the three-phase power supply and the motor.

[0009] The automatic phase sequence switching control system for the power supply of the underground rock drilling rig also includes a pressure sensor PS installed on the outlet pipeline of the water supply system controlled by the motor.

[0010] The automatic phase sequence switching control system for the power supply of the underground drilling rig in the mine also includes a control circuit; the control circuit includes a start button SB1, a stop button SB2, a relay KA1, and a time relay KT;

[0011] The normally open start button SB1, the normally closed stop button SB2, and the coil of the relay KA1 are connected in series between the positive and negative terminals of the DC power supply; the first normally open contact of the relay KA1 is also connected in parallel with the start button SB1.

[0012] The second normally open contact of relay KA1 is connected in series with time relay KT between the positive and negative terminals of the DC power supply.

[0013] The normally open contact of contactor KM1 is connected in series with the coil of contactor KM3 to form the positive sequence second control branch. The normally open contact of contactor KM2 is connected in series with the coil of contactor KM4 to form the reverse sequence second control branch. The positive sequence second control branch and the reverse sequence second control branch are connected in parallel, and then connected in series with the normally closed contact of pressure sensor PS between the positive and negative terminals of the DC power supply. The normally closed contact of time relay KT is connected in parallel with the normally closed contact of pressure sensor PS.

[0014] As a further improvement to the automatic phase sequence switching control system for the underground drilling rig power supply, the control circuit also includes an alarm branch, in which the light alarm and the sound alarm are connected in parallel and then connected in series between the positive and negative terminals of the DC power supply with the normally open contact of the time relay KT and the normally open contact of the pressure sensor PS.

[0015] As a further improvement to the automatic phase sequence switching control system for the underground drilling rig in the mine, the normally closed contact of contactor KM1 is also connected in series in the first control branch of the reverse sequence.

[0016] As a further improvement to the automatic phase sequence switching control system for the underground drilling rig in the mine, the normally closed contact of contactor KM2 is also connected in series in the first control branch of the positive sequence.

[0017] Compared with the prior art, the present invention has the following positive effects:

[0018] 1. This utility model detects the current phase sequence through a phase sequence relay. If the phase sequence is incorrect, it will trigger contactor KM3 to open and KM4 to close, thereby automatically switching the connection relationship between the power supply and the motor to prevent the motor from starting in reverse.

[0019] 2. This utility model also uses a pressure sensor to determine whether the pipeline pressure is normal after the motor starts, and introduces a forced power-off mechanism. If the pressure is abnormal, it indicates that there may be a problem with the current phase sequence relay and it cannot correctly identify the phase sequence. The contactors KM3 and KM4 will be automatically disconnected to achieve forced power-off and prevent the accident from escalating.

[0020] 3. This utility model uses a time relay KT to control the intervention timing of the pressure sensor. Upon initial startup, the normally closed contact of the time relay KT short-circuits the normally closed contact of the pressure sensor, preventing a forced power-off mechanism from being triggered incorrectly due to low pressure during startup. After a preset time, the normally closed contact of the time relay KT opens, and the normally closed contact of the pressure sensor engages. If the pressure is still within a low range at this point, a forced power-off is then initiated. Attached Figure Description

[0021] Figure 1 This is the electrical schematic diagram of the main circuit in this utility model;

[0022] Figure 2 This is the electrical schematic diagram of the control circuit in this utility model. Detailed Implementation

[0023] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0024] An automatic phase sequence switching control system for power supply of a rock drilling rig in a mine includes a main circuit for supplying power to the motor.

[0025] like Figure 1 In the main circuit, the three-phase power supply is connected to the motor sequentially through the main switch Q100 (model W23-X1A1G-10) and circuit breaker 1F100 (model W23-X1A1G-25). In this embodiment, the motor is the water pump motor of the water supply system in the rock drilling rig. The main circuit also includes a phase sequence relay, contactors KM1, KM2, KM3, and KM4.

[0026] The three-phase power supply is connected to a phase sequence relay, which (model XJ12) has normally open and normally closed contacts that operate synchronously according to the phase sequence of the power supply. The normally open contact of the phase sequence relay is connected in series with the coil of contactor KM2 to form a reverse-sequence first control branch, and the normally closed contact of the phase sequence relay is connected in series with the coil of contactor KM1 to form a positive-sequence first control branch. The reverse-sequence and positive-sequence first control branches are connected in parallel between two phases of the three-phase power supply. The phase sequence relay is used to detect the phase sequence of the power supply. When the phase sequence is correct, the normally open and normally closed contacts remain in their original states, contactor KM1 is energized, and contactor KM2 is de-energized.

[0027] Furthermore, to improve reliability, the normally closed contact of contactor KM1 is connected in series in the first control branch of the reverse sequence, and the normally closed contact of contactor KM2 is connected in series in the first control branch of the forward sequence, thereby realizing the interlocking of contactors KM1 and KM2.

[0028] Furthermore, the normally open contacts of contactor KM3 and contactor KM4 are connected in parallel. The normally open contacts of contactor KM3 are used to realize the positive sequence connection between the three-phase power supply and the motor, and the normally open contacts of contactor KM4 are used to realize the reverse sequence connection between the three-phase power supply and the motor.

[0029] The automatic phase sequence switching control system for the power supply of the underground rock drilling rig also includes a pressure sensor PS installed on the outlet pipe of the water supply system controlled by the motor. The pressure sensor controls the action of its internal contacts based on the relationship between the detected pressure and a preset threshold.

[0030] like Figure 2 The automatic phase sequence switching control system for the power supply of the underground drilling rig in the mine also includes a control circuit. The control circuit includes a start button SB1, a stop button SB2, a relay KA1, and a time relay KT.

[0031] The normally open start button SB1, the normally closed stop button SB2, and the coil of the relay KA1 are connected in series between the positive and negative terminals of the DC power supply; the first normally open contact of the relay KA1 is also connected in parallel with the start button SB1.

[0032] The second normally open contact of relay KA1 is connected in series with time relay KT between the positive and negative terminals of the DC power supply.

[0033] The normally open contact of contactor KM1 is connected in series with the coil of contactor KM3 to form the positive sequence second control branch. The normally open contact of contactor KM2 is connected in series with the coil of contactor KM4 to form the reverse sequence second control branch. The positive sequence second control branch and the reverse sequence second control branch are connected in parallel, and then connected in series with the normally closed contact of pressure sensor PS between the positive and negative terminals of the DC power supply. The normally closed contact of time relay KT is connected in parallel with the normally closed contact of pressure sensor PS.

[0034] The contactor is model NXC-65.

[0035] Furthermore, the control circuit also includes an alarm branch, in which the light alarm and the sound alarm are connected in parallel and then connected in series between the positive and negative terminals of the DC power supply with the normally open contact of the time relay KT and the normally open contact of the pressure sensor PS.

[0036] The working process of this system is as follows:

[0037] When the operator presses the start button SB1, relay KA1 is energized. Simultaneously, its first normally open contact completes the start-up self-locking, and its second normally open contact energizes time relay KT. Time relay KT begins timing, and its normally closed contact remains closed while its normally open contact remains open. Therefore, the normally closed contact of pressure sensor PS is short-circuited, and the alarm branch does not operate. Simultaneously, if the phase sequence relay determines the phase sequence is correct, contactor KM1 is energized, which in turn energizes contactor KM3 through the control circuit, closing its normally open contact, thus achieving a positive sequence connection between the three-phase power supply and the motor, and the motor begins normal operation. If the phase sequence relay determines the phase sequence is incorrect, contactor KM2 is energized, which in turn energizes contactor KM4 through the control circuit, closing its normally open contact, achieving a reverse sequence connection between the three-phase power supply and the motor. Since the power phase sequence is also incorrect in this case, the motor can still operate normally in the forward direction.

[0038] However, if the phase sequence relay itself is faulty and cannot correctly identify the phase sequence, it will cause the motor to operate in reverse after starting, resulting in no pressure in the outlet pipe. The addition of a time relay KT and a pressure sensor PS can solve this problem: after the time relay KT finishes timing, its normally closed contact opens and its normally open contact closes. At this time, the normally closed contact of the pressure sensor PS is no longer short-circuited, and the alarm branch will trigger an alarm based on the state of the normally open contact of the pressure sensor PS. If the motor is in reverse at this time, the pressure in the outlet pipe will inevitably be lower than the preset threshold, causing the normally closed contact of the pressure sensor PS to open and its normally open contact to close. Both the forward and reverse sequence second control branches will lose power, and consequently, the control contactors KM3 and KM4 will be de-energized, completing the forced power cut-off of the main circuit. Furthermore, the closing of the normally open contact of the pressure sensor PS will trigger the light and sound alarms, prompting the operator to check.

[0039] It should be noted that, as will be apparent to those skilled in the art, this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. The scope of this utility model is defined by the claims rather than the foregoing description.

Claims

1. An automatic phase sequence switching control system for power supply of a mining underground drilling rig, comprising a main circuit for supplying power to the motor, wherein the three-phase power supply in the main circuit is connected to the motor sequentially through a main switch Q100 and a circuit breaker 1F100, characterized in that: The main circuit also includes phase sequence relays, contactors KM1, KM2, KM3, and KM4; The three-phase power supply is connected to a phase sequence relay, which has normally open and normally closed contacts that operate synchronously according to the phase sequence of the power supply. The normally open contacts of the phase sequence relay are connected in series with the coil of contactor KM2 to form a reverse sequence first control branch, and the normally closed contacts of the phase sequence relay are connected in series with the coil of contactor KM1 to form a positive sequence first control branch. The reverse sequence first control branch and the positive sequence first control branch are connected in parallel between two phases of the three-phase power supply. The normally open contact of contactor KM3 is connected in parallel with the normally open contact of contactor KM4. The normally open contact of contactor KM3 is used to realize the positive sequence connection between the three-phase power supply and the motor, and the normally open contact of contactor KM4 is used to realize the reverse sequence connection between the three-phase power supply and the motor. The automatic phase sequence switching control system for the power supply of the underground rock drilling rig also includes a pressure sensor PS installed on the outlet pipeline of the water supply system controlled by the motor. The automatic phase sequence switching control system for the power supply of the underground drilling rig in the mine also includes a control circuit; the control circuit includes a start button SB1, a stop button SB2, a relay KA1, and a time relay KT; The normally open start button SB1, the normally closed stop button SB2, and the coil of the relay KA1 are connected in series between the positive and negative terminals of the DC power supply; the first normally open contact of the relay KA1 is also connected in parallel with the start button SB1. The second normally open contact of relay KA1 is connected in series with time relay KT between the positive and negative terminals of the DC power supply. The normally open contact of contactor KM1 is connected in series with the coil of contactor KM3 to form the positive sequence second control branch. The normally open contact of contactor KM2 is connected in series with the coil of contactor KM4 to form the reverse sequence second control branch. The positive sequence second control branch and the reverse sequence second control branch are connected in parallel, and then connected in series with the normally closed contact of pressure sensor PS between the positive and negative terminals of the DC power supply. The normally closed contact of time relay KT is connected in parallel with the normally closed contact of pressure sensor PS.

2. The automatic phase sequence switching control system for underground rock drilling rigs in mines as described in claim 1, characterized in that: The control circuit also includes an alarm branch, in which the light alarm and the sound alarm are connected in parallel and then connected in series between the positive and negative terminals of the DC power supply, along with the normally open contact of the time relay KT and the normally open contact of the pressure sensor PS.

3. The automatic phase sequence switching control system for underground rock drilling rigs in mines as described in claim 1 or 2, characterized in that: The normally closed contact of contactor KM1 is also connected in series in the first control branch of the reverse sequence.

4. The automatic phase sequence switching control system for underground rock drilling rigs in mines as described in claim 1 or 2, characterized in that: The normally closed contact of contactor KM2 is also connected in series in the first control branch of the positive sequence.

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