Safety detection device and method for mining frequency converter

Abstract

The invention discloses a mining frequency converter safety detection device and method, and the device directly controls the on-off of a main loop contactor through a frequency converter control chip, obtains the control power state of the main contactor and the contact closing state of an internal onboard relay through the frequency converter control chip, improves the fault diagnosis information, saves the troubleshooting time, and improves the detection efficiency. In addition, the safety detection circuit provided by the invention can also automatically and quickly cut off a main loop contactor to protect the mining frequency converter under the condition that the frequency converter control power supply is powered down, and a PLC system does not need to carry out additional processing. According to the mining frequency converter protection method and device, PLC system resources are saved, the problem that the mining frequency converter is damaged due to the fact that the mining frequency converter is not protected in time at present is solved, fault diagnosis information is perfected, and the power failure protection function of a control power source of the mining frequency converter is added.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine frequency converters, and in particular relates to a safety detection device and method for mine frequency converters. Background Art

[0002] Mining-grade VFDs are explosion-proof inverters designed for special operations. Currently, mining-grade VFDs are widely used in coal mining. Due to their excellent performance and significant energy-saving benefits, they are widely used across various industries. Furthermore, as energy conservation, consumption reduction, and low carbon emissions become the fundamental needs of social development, the explosion-proof industry is rapidly developing, and the use of mining-grade VFDs is also becoming increasingly widespread. Mining-grade VFDs have rated voltages ranging from 660 to 1140V and rated powers ranging from 5.5 to 630kW.

[0003] At present, the main circuit of the common mining inverter generally adopts Figure 1 In the structure shown, after the main circuit power enters the explosion-proof electric control box, it first passes through the circuit breaker QF1. The circuit breaker is used for short-circuit protection of the main circuit. The circuit breaker can also be replaced by an isolating switch in series with a fuse. The circuit breaker is divided into multiple circuits, one of which is connected to the contactor KM1. When an emergency such as a line short circuit occurs, the inverter is mainly protected by promptly cutting off KM1.

[0004] like Figure 1 In the prior art shown, power supply 1 is the KM1 coil power supply, and power supply 2 is the inverter control power supply. During normal operation, the relay KA1 coil remains energized. When the inverter detects an emergency fault such as a short circuit fault, it notifies the PLC module in the form of a switch node or communication. The PLC module stops powering the relay KA1 coil, the KA1-1 normally open contact is disconnected, the KM1 coil loses power, and the KM1-1 contact is disconnected, thereby achieving the purpose of protecting the inverter. However, this technology has the problem of untimely protection, because the emergency fault is detected by the inverter, and the inverter needs to inform the PLC module of the fault signal before the PLC module drives the relay KA1 to turn off the main contactor contact KM1-1. The execution cycle of the PLC module is in the ms level, and the delay during this period may cause the inverter to be damaged due to untimely protection.

[0005] Patent publication number CN104967088B discloses a protection system for a mining inverter. This technology uses a PLC system to monitor the main circuit. For general faults, the PLC system only controls the inverter to lock or shut down without disconnecting the main contactor. For major faults, the PLC system disconnects contactor KM1, cutting off the inverter's power supply. While this technology reduces damage to the inverter's internal components caused by frequent activation of the main contactor, the entire protection operation is performed by the PLC, which still poses the problem of untimely inverter protection. Summary of the Invention

[0006] The present invention aims to provide a simple and feasible protection method and safety detection device for a mine frequency converter, which uses a frequency converter control chip to directly control the on and off of the main circuit contactor, thereby eliminating the time delay of disconnecting the contactor through the PLC system in the prior art, and solving the problem of frequency converter damage caused by untimely protection of the current mine frequency converter.

[0007] The first object of the present invention is to provide the following technical solution: a mine frequency converter safety detection device, comprising:

[0008] A first connector J1, a second connector J2, a switch control unit, a first state feedback unit and a second state feedback unit; wherein,

[0009] The front end of the first connector J1 is connected to the main circuit contactor coil power supply, and the rear end of the first connector J1 is connected to the first state feedback unit; the front end of the second connector J2 is connected to the main circuit contactor coil, and the rear end of the second connector J2 is connected to the second state feedback unit;

[0010] The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected in parallel at both ends of the switch control unit; the second pin J1-2 of the first connector J1 and the second pin J2-2 of the second connector J2 are short-circuited.

[0011] Furthermore, the switch control unit includes: an onboard relay K1, a first control power supply VCC1, a first resistor R1, an N-channel MOS transistor Q1, a second resistor R2 and a first I / O port Port1; wherein,

[0012] The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected to both ends of the normally open contact of the onboard relay K1; the first control power supply VCC1, the first resistor R1, the coil K1-1 of the onboard relay K1, and the N-channel MOS transistor Q1 are connected in series in sequence, the D pole of the N-channel MOS transistor Q1 is connected to the coil K1-1 of the onboard relay K1, and the S pole of the N-channel MOS transistor Q1 is grounded; the second resistor R2 is connected in parallel to the G pole and S pole of the N-channel MOS transistor Q1; the first I / O port Port1 is connected to the G pole of the N-channel MOS transistor Q1, and the high and low level signals of the first I / O port Port1 are controlled by the mining inverter control chip.

[0013] Furthermore, the first state feedback unit includes: a third resistor R3, a fourth resistor R4, a first jumper Jumper1, a second jumper Jumper2, a first rectifier bridge D1, a first optocoupler U-1, a second control power supply VCC2, a fifth resistor R5 and a second I / O port Port2; wherein,

[0014] The two ends of the rear electrode of the first connector J1 are respectively connected to the third resistor R3, the third resistor R3 is connected to the first jumper Jumper1, and the fourth resistor R4 is connected to the second jumper Jumper2;

[0015] When the power supply signal at both ends of the rear stage of the first connector J1 is AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1.

[0016] When the power supply signal at both ends of the rear stage of the first connector J1 is DC, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2;

[0017] The second control power supply VCC2 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to the collector of the output end of the first optocoupler U-1, and the emitter of the output end of the first optocoupler U-1 is grounded; the second I / O port Prot2 is connected to the collector of the output end of the first optocoupler U-1, and the high and low level signals of the second I / O port Port2 are used to feed back the status information of whether the relay coil power supply is powered to the mining inverter control chip.

[0018] Furthermore, the second state feedback unit includes: a sixth resistor R6, a seventh resistor R7, a third jumper Jumper3, a fourth jumper Jumper4, a second rectifier bridge D2, a second optocoupler U-2, a second control power supply VCC2, an eighth resistor R8 and a third I / O port Port3; wherein,

[0019] The second connector J2 has two rear ends connected to a sixth resistor R6, the sixth resistor R6 is connected to a third jumper Jumper3, and the seventh resistor R7 is connected to a fourth jumper Jumper4.

[0020] When the power signal at both ends of the second connector J2 is AC power, the third jumper Jumper 3 connects the rear end of the sixth resistor R6 to one end of the AC side of the second rectifier bridge D2, and the fourth jumper Jumper 4 connects the rear end of the seventh resistor R7 to the other end of the AC side of the second rectifier bridge D2. The DC side positive electrode of the second rectifier bridge D2 is connected to the anode of the input end of the second optocoupler U-2, and the DC side negative electrode of the second rectifier bridge D2 is connected to the cathode of the input end of the second optocoupler U-2.

[0021] If the power signal at both ends of the second connector J2 is direct current, the rear end of the sixth resistor R6 is connected to the anode of the input end of the second optocoupler U-2 through the third jumper Jumper3, and the rear end of the seventh resistor R7 is connected to the cathode of the input end of the second optocoupler U-2 through the fourth jumper Jumper4;

[0022] The second control power supply VCC2 is connected to the eighth resistor R8, the eighth resistor R8 is connected to the collector of the output end of the second optocoupler U-2, and the emitter of the output end of the second optocoupler U-2 is grounded; the third I / O port Prot3 is connected to the collector of the output end of the second optocoupler U-2, and the high and low level signals of the third I / O port Port3 are used to feedback the status information of whether the normally open contact of the on-board relay K1 is closed to the mining inverter control chip.

[0023] Furthermore, the main circuit of the mine frequency converter includes a circuit breaker QF1, a main circuit contactor KM1, an incoming line filter Z1, an incoming line reactor L1 and a mine frequency converter U1; wherein,

[0024] The main circuit contactor KM1 is used to control the on and off of the high-voltage power supply of the mining inverter U1; the mining inverter U1 is powered by the inverter control power supply.

[0025] The second object of the present invention is to provide a mine frequency converter safety detection method, which uses the mine frequency converter safety detection device of the above technical solution for detection, including:

[0026] S1. Before the contactor of the main circuit contactor of the mine inverter is closed, the mine inverter self-test is performed. If the self-test is normal, step S2 is executed. If the self-test of the mine inverter is abnormal, the process returns to step S1.

[0027] S2. The switch between the power supply of the main circuit contactor coil of the mine inverter and the main circuit contactor coil of the mine inverter is closed through the mine inverter safety detection device. After the main circuit contactor coil of the mine inverter is energized, the main circuit contactor contacts of the mine inverter are closed.

[0028] S3. After the contacts of the main circuit contactor of the mine inverter are closed, if an emergency occurs in the mine inverter, the switch between the power supply of the main circuit contactor coil of the mine inverter and the main circuit contactor coil of the mine inverter is disconnected, and then the contacts of the main circuit contactor of the mine inverter are disconnected, so as to play a role in timely protection of the mine inverter.

[0029] Furthermore, the method further includes the step of detecting whether the main circuit contactor coil power supply is energized;

[0030] According to the AC and DC conditions of the main circuit contactor coil power supply, determine the short circuit status of the first jumper Jumper1 and the second jumper Jumper2;

[0031] When the power supply signal at both ends of the rear stage of the first connector J1 is AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1.

[0032] When the power supply signal at both ends of the rear stage of the first connector J1 is DC, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2;

[0033] If the main circuit contactor coil power supply is powered, the second I / O port Port2 outputs a low-level signal; if the main circuit contactor coil power supply is de-energized, the second I / O port Port2 outputs a high-level signal. The mining inverter control chip obtains the status of the main circuit contactor coil power supply through the level signal output by the second I / O port Port2, so as to accurately locate the fault diagnosis.

[0034] Furthermore, the method further includes the step of detecting whether the onboard relay K1 is closed;

[0035] If the normally open contact of the onboard relay K1 is closed, the third I / O port Prot3 outputs a low-level signal; if the normally open contact of the onboard relay K1 is not closed, the third I / O port Prot3 outputs a high-level signal; the mining inverter control chip obtains the opening and closing status of the normally open contact of the onboard relay K1 through the level signal output by the third I / O port Prot3, so as to accurately locate the fault diagnosis.

[0036] Compared with the prior art, the advantages of the present invention are:

[0037] The mine frequency converter safety detection device of the present invention directly controls the on and off of the main circuit contactor through the frequency converter control chip, saving the time delay of cutting off the contactor through the PLC system in the prior art, solving the problem of damage to the current mine frequency converter caused by untimely protection. The safety detection circuit provided by the present invention can obtain the main contactor control power supply status and the internal onboard relay contact closure status through the frequency converter control chip, improving fault diagnosis information and saving troubleshooting time. In addition, the safety detection circuit provided by the present invention can also automatically and quickly cut off the main circuit contactor to protect the mine frequency converter when the frequency converter control power is cut off, without the need for additional processing by the PLC system. Therefore, the mine frequency converter protection method and safety detection circuit provided by the present invention save PLC system resources while solving the problem of damage to the mine frequency converter caused by untimely protection of the mine frequency converter, while improving fault diagnosis information and adding a power-off protection function for the mine frequency converter control power. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the electrical principle used in the main circuit of a mine frequency converter in the prior art;

[0039] Figure 2 A schematic structural diagram of a mine frequency converter safety detection device provided by the present invention;

[0040] Figure 3 A schematic diagram of the electrical principle of a mine frequency converter safety detection device provided by the present invention;

[0041] Figure 4 A schematic flow chart of a mine frequency converter safety detection method provided by the present invention. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] like Figure 2 and Figure 3 Shown: A mine frequency converter safety detection device, comprising:

[0044] A first connector J1, a second connector J2, a switch control unit, a first state feedback unit and a second state feedback unit; wherein,

[0045] The front end of the first connector J1 is connected to the main circuit contactor coil power supply, and the rear end of the first connector J1 is connected to the first state feedback unit; the front end of the second connector J2 is connected to the main circuit contactor coil, and the rear end of the second connector J2 is connected to the second state feedback unit;

[0046] The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected in parallel at both ends of the switch control unit; the second pin J1-2 of the first connector J1 and the second pin J2-2 of the second connector J2 are short-circuited.

[0047] Figure 2 In the figure, power supply 1 is the power supply for the contactor coil of the main circuit of the mining inverter, and power supply 2 is the control power supply of the mining inverter.

[0048] The switch control unit includes: an onboard relay K1, a first control power supply VCC1, a first resistor R1, an N-channel MOS transistor Q1, a second resistor R2 and a first I / O port Port1;

[0049] The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected to both ends of the normally open contact of the onboard relay K1; the first control power supply VCC1, the first resistor R1, the coil K1-1 of the onboard relay K1, and the N-channel MOS transistor Q1 are connected in series in sequence, the D pole of the N-channel MOS transistor Q1 is connected to the coil K1-1 of the onboard relay K1, and the S pole of the N-channel MOS transistor Q1 is grounded; the second resistor R2 is connected in parallel to the G pole and S pole of the N-channel MOS transistor Q1; the first I / O port Port1 is connected to the G pole of the N-channel MOS transistor Q1, and the high and low level signals of the first I / O port Port1 are controlled by the mining inverter control chip.

[0050] The first state feedback unit includes: a third resistor R3, a fourth resistor R4, a first jumper Jumper1, a second jumper Jumper2, a first rectifier bridge D1, a first optical coupler U-1, a second control power supply VCC2, a fifth resistor R5 and a second I / O port Port2; wherein,

[0051] The two ends of the rear electrode of the first connector J1 are respectively connected to the third resistor R3, the third resistor R3 is connected to the first jumper Jumper1, and the fourth resistor R4 is connected to the second jumper Jumper2;

[0052] When the power supply signal at both ends of the rear stage of the first connector J1 is AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1.

[0053] When the power supply signal at both ends of the rear stage of the first connector J1 is DC, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2;

[0054] The second control power supply VCC2 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to the collector of the output end of the first optocoupler U-1, and the emitter of the output end of the first optocoupler U-1 is grounded; the second I / O port Prot2 is connected to the collector of the output end of the first optocoupler U-1, and the high and low level signals of the second I / O port Port2 are used to feed back the status information of whether the relay coil power supply is powered to the mining inverter control chip.

[0055] The second state feedback unit includes: a sixth resistor R6, a seventh resistor R7, a third jumper Jumper3, a fourth jumper Jumper4, a second rectifier bridge D2, a second optical coupler U-2, a second control power supply VCC2, an eighth resistor R8 and a third I / O port Port3; wherein,

[0056] The second connector J2 has two rear ends connected to a sixth resistor R6, the sixth resistor R6 is connected to a third jumper Jumper3, and the seventh resistor R7 is connected to a fourth jumper Jumper4.

[0057] When the power signal at both ends of the second connector J2 is AC power, the third jumper Jumper 3 connects the rear end of the sixth resistor R6 to one end of the AC side of the second rectifier bridge D2, and the fourth jumper Jumper 4 connects the rear end of the seventh resistor R7 to the other end of the AC side of the second rectifier bridge D2. The DC side positive electrode of the second rectifier bridge D2 is connected to the anode of the input end of the second optocoupler U-2, and the DC side negative electrode of the second rectifier bridge D2 is connected to the cathode of the input end of the second optocoupler U-2.

[0058] If the power signal at both ends of the second connector J2 is direct current, the rear end of the sixth resistor R6 is connected to the anode of the input end of the second optocoupler U-2 through the third jumper Jumper3, and the rear end of the seventh resistor R7 is connected to the cathode of the input end of the second optocoupler U-2 through the fourth jumper Jumper4;

[0059] The second control power supply VCC2 is connected to the eighth resistor R8, the eighth resistor R8 is connected to the collector of the output end of the second optocoupler U-2, and the emitter of the output end of the second optocoupler U-2 is grounded; the third I / O port Prot3 is connected to the collector of the output end of the second optocoupler U-2, and the high and low level signals of the third I / O port Port3 are used to feedback the status information of whether the normally open contact of the on-board relay K1 is closed to the mining inverter control chip.

[0060] The main circuit of the mine frequency converter includes circuit breaker QF1, main circuit contactor KM1, incoming line filter Z1, incoming line reactor L1 and mine frequency converter U1; among them,

[0061] The main circuit contactor KM1 is used to control the on and off of the high-voltage power supply of the mining inverter U1; the mining inverter U1 is powered by the inverter control power supply.

[0062] like Figure 4 As shown, the present invention provides a mine frequency converter safety detection method, which uses the mine frequency converter safety detection device of the above technical solution for detection, including:

[0063] S1. Before the contactor of the main circuit contactor of the mine inverter is closed, the mine inverter self-test is performed. If the self-test is normal, step S2 is executed. If the self-test of the mine inverter is abnormal, the process returns to step S1.

[0064] S2. Through the mine inverter safety detection device, close the switch between the mine inverter main circuit contactor coil power supply and the mine inverter main circuit contactor coil. After the mine inverter main circuit contactor coil is energized, the mine inverter main circuit contactor contacts are closed.

[0065] Because the inverter has self-checked normally in step S1, the mining inverter control chip sends a high-level signal to port Port1, the N-channel MOS tube Q1 is turned on, the onboard relay K1 coil is energized, the K1 normally open contact is closed, the contactor KM1 coil is energized, the contactor contact KM1-1 is closed, and the main circuit of the mining inverter U1 is powered on. Among them, the resistor R1 is used for current limiting, and the resistor R2 is used for level clamping to prevent the MOS tube Q1 from malfunctioning.

[0066] S3. After the contacts of the main circuit contactor of the mine inverter are closed, if an emergency occurs in the mine inverter, the switch between the power supply of the main circuit contactor coil of the mine inverter and the main circuit contactor coil of the mine inverter is disconnected, and then the contacts of the main circuit contactor of the mine inverter are disconnected, so as to play a role in timely protection of the mine inverter.

[0067] When the main circuit of the mining inverter U1 is energized, if an emergency such as a main circuit short circuit occurs, the inverter DSP control chip can set the port Port1 level signal from high level "1" to low level "0" through the internal safety detection circuit. The GS level voltage of the N-channel MOS tube is turned off because it is lower than the threshold, thereby disconnecting the normally open contact of the on-board relay K1, de-energizing the contactor KM1 coil, and disconnecting the contactor contact KM1-1, thus timely protecting the mining inverter.

[0068] Furthermore, the method further includes the step of detecting whether the main circuit contactor coil power supply is energized;

[0069] According to the AC and DC conditions of the main circuit contactor coil power supply, determine the short circuit status of the first jumper Jumper1 and the second jumper Jumper2;

[0070] When the power supply signal at both ends of the rear stage of the first connector J1 is AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1.

[0071] When the power supply signal at both ends of the rear stage of the first connector J1 is DC, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2;

[0072] If the main circuit contactor coil power supply is powered, the second I / O port Port2 outputs a low-level signal; if the main circuit contactor coil power supply is de-energized, the second I / O port Port2 outputs a high-level signal. The mining inverter control chip obtains the status of the main circuit contactor coil power supply through the level signal output by the second I / O port Port2, so as to accurately locate the fault diagnosis.

[0073] Furthermore, the method further includes the step of detecting whether the onboard relay K1 is closed;

[0074] If the normally open contact of the onboard relay K1 is closed, the third I / O port Prot3 outputs a low-level signal; if the normally open contact of the onboard relay K1 is not closed, the third I / O port Prot3 outputs a high-level signal; the mining inverter control chip obtains the opening and closing status of the normally open contact of the onboard relay K1 through the level signal output by the third I / O port Prot3, so as to accurately locate the fault diagnosis.

[0075] When the control power supply 2 of the mining inverter U1 loses power, the internal power supply VCC1 of the inverter loses power, the coil of the onboard relay K1 loses power, the normally open contact of the onboard relay K1 is disconnected, the coil of the contactor KM1 loses power, and the contactor KM1-1 is disconnected, which timely protects the mining inverter.

[0076] Compared with the prior art, the advantages of the present invention are:

[0077] The mine frequency converter safety detection device of the present invention directly controls the on and off of the main circuit contactor through the frequency converter control chip, saving the time delay of cutting off the contactor through the PLC system in the prior art, solving the problem of damage to the current mine frequency converter caused by untimely protection. The safety detection circuit provided by the present invention can obtain the main contactor control power supply status and the internal onboard relay contact closure status through the frequency converter control chip, improving fault diagnosis information and saving troubleshooting time. In addition, the safety detection circuit provided by the present invention can also automatically and quickly cut off the main circuit contactor to protect the mine frequency converter when the frequency converter control power is cut off, without the need for additional processing by the PLC system. Therefore, the mine frequency converter protection method and safety detection circuit provided by the present invention save PLC system resources while solving the problem of damage to the mine frequency converter caused by untimely protection of the mine frequency converter, while improving fault diagnosis information and adding a power-off protection function for the mine frequency converter control power.

[0078] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0080] Although embodiments of the present invention have been shown and described above, it will be understood that the embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace, and vary the embodiments within the scope of the present invention.

Claims

1. A mine frequency converter safety detection device, characterized in that: include: A first connector J1, a second connector J2, a switch control unit, a first state feedback unit and a second state feedback unit; wherein, The front end of the first connector J1 is connected to the main circuit contactor coil power supply, and the rear end of the first connector J1 is connected to the first state feedback unit; the front end of the second connector J2 is connected to the main circuit contactor coil, and the rear end of the second connector J2 is connected to the second state feedback unit; The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected in parallel at both ends of the switch control unit; the second pin J1-2 of the first connector J1 and the second pin J2-2 of the second connector J2 are short-circuited.

2. A mine frequency converter safety detection device according to claim 1, characterized in that: The switch control unit includes: an onboard relay K1, a first control power supply VCC1, a first resistor R1, an N-channel MOS transistor Q1, a second resistor R2 and a first I / O port Port1; wherein, The first pin J1-1 of the first connector J1 and the first pin J2-1 of the second connector J2 are connected to both ends of the normally open contact of the onboard relay K1; the first control power supply VCC1, the first resistor R1, the coil K1-1 of the onboard relay K1, and the N-channel MOS transistor Q1 are connected in series in sequence, the D pole of the N-channel MOS transistor Q1 is connected to the coil K1-1 of the onboard relay K1, and the S pole of the N-channel MOS transistor Q1 is grounded; the second resistor R2 is connected in parallel to the G pole and the S pole of the N-channel MOS transistor Q1; the first I / O port Port1 is connected to the G pole of the N-channel MOS transistor Q1, and the high and low level signals of the first I / O port Port1 are controlled by the mining inverter control chip.

3. A mine frequency converter safety detection device according to claim 1, characterized in that: The first state feedback unit includes: a third resistor R3, a fourth resistor R4, a first jumper Jumper1, a second jumper Jumper2, a first rectifier bridge D1, a first optical coupler U-1, a second control power supply VCC2, a fifth resistor R5 and a second I / O port Port2; wherein, Two ends of the rear electrode of the first connector J1 are respectively connected to the third resistor R3, the third resistor R3 is connected to the first jumper Jumper1, and the fourth resistor R4 is connected to the second jumper Jumper2; When the power supply signals at both ends of the rear stage of the first connector J1 are AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1. When the power supply signals at both ends of the rear stage of the first connector J1 are direct current, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2; The second control power supply VCC2 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to the collector of the output end of the first optocoupler U-1, and the emitter of the output end of the first optocoupler U-1 is grounded; the second I / O port Prot2 is connected to the collector of the output end of the first optocoupler U-1, and the high and low level signals of the second I / O port Port2 are used to feed back the status information of whether the relay coil power supply is powered to the mining inverter control chip.

4. A mine frequency converter safety detection device according to claim 1, characterized in that: The second state feedback unit includes: a sixth resistor R6, a seventh resistor R7, a third jumper Jumper3, a fourth jumper Jumper4, a second rectifier bridge D2, a second optical coupler U-2, a second control power supply VCC2, an eighth resistor R8 and a third I / O port Port3; wherein, The rear ends of the second connector J2 are respectively connected to the sixth resistor R6, the sixth resistor R6 is connected to the third jumper Jumper3, and the seventh resistor R7 is connected to the fourth jumper Jumper4; When the power supply signal at both ends of the second connector J2 is AC power, the third jumper Jumper3 connects the rear stage of the sixth resistor R6 to one end of the AC side of the second rectifier bridge D2, and the fourth jumper Jumper4 connects the rear stage of the seventh resistor R7 to the other end of the AC side of the second rectifier bridge D2. The DC side positive electrode of the second rectifier bridge D2 is connected to the anode of the input end of the second optocoupler U-2, and the DC side negative electrode of the second rectifier bridge D2 is connected to the cathode of the input end of the second optocoupler U-2; If the power supply signal at both ends of the second connector J2 is direct current, the rear end of the sixth resistor R6 is connected to the anode of the input end of the second optical coupler U-2 through the third jumper Jumper3, and the rear end of the seventh resistor R7 is connected to the cathode of the input end of the second optical coupler U-2 through the fourth jumper Jumper4; The second control power supply VCC2 is connected to the eighth resistor R8, the eighth resistor R8 is connected to the collector of the output end of the second optocoupler U-2, and the emitter of the output end of the second optocoupler U-2 is grounded; the third I / O port Prot3 is connected to the collector of the output end of the second optocoupler U-2, and the high and low level signals of the third I / O port Port3 are used to feedback the status information of whether the normally open contact of the on-board relay K1 is closed to the mining inverter control chip.

5. A mine frequency converter safety detection device according to claim 1, characterized in that: The main circuit of the mine frequency converter includes a circuit breaker QF1, a main circuit contactor KM1, an incoming line filter Z1, an incoming line reactor L1 and a mine frequency converter U1; wherein, The main circuit contactor KM1 is used to control the on and off of the high-voltage power supply of the mining frequency converter U1; the mining frequency converter U1 is powered by the frequency converter control power supply.

6. A method for detecting safety of a mine frequency converter, using the mine frequency converter safety detection device according to any one of claims 1 to 5 for detection, characterized in that: include: S1. Before the contactor of the main circuit contactor of the mining inverter is closed, the mining inverter is self-checked. If the self-check is normal, step S2 is executed. If the self-check of the mining inverter is abnormal, the process returns to step S1. S2. The switch between the power supply of the main circuit contactor coil of the mine inverter and the main circuit contactor coil of the mine inverter is closed by the mine inverter safety detection device. After the main circuit contactor coil of the mine inverter is energized, the main circuit contactor contacts of the mine inverter are closed. S3. After the contacts of the main circuit contactor of the mine inverter are closed, if an emergency occurs in the mine inverter, the switch between the power supply of the main circuit contactor coil of the mine inverter and the main circuit contactor coil of the mine inverter is disconnected, and then the contacts of the main circuit contactor of the mine inverter are disconnected, so as to play a role in timely protection of the mine inverter.

7. The mine frequency converter safety detection method according to claim 6 is characterized in that: The step of detecting whether the main circuit contactor coil power supply is energized is also included; Determine the short circuit status of the first jumper Jumper1 and the second jumper Jumper2 according to the AC and DC status of the main circuit contactor coil power supply; When the power supply signals at both ends of the rear stage of the first connector J1 are AC, the first jumper Jumper1 connects the rear stage of the third resistor R3 to one end of the AC side of the first rectifier bridge D1, and the second jumper Jumper2 connects the rear stage of the fourth resistor R4 to the other end of the AC side of the first rectifier bridge D1. The DC side positive electrode of the first rectifier bridge D1 is connected to the anode of the input end of the first optocoupler U-1, and the DC side negative electrode of the first rectifier bridge D1 is connected to the cathode of the input end of the first optocoupler U-1. When the power supply signals at both ends of the rear stage of the first connector J1 are direct current, the rear stage of the third resistor R3 is connected to the anode of the input end of the first optocoupler U-1 through the first jumper Jumper1, and the rear stage of the fourth resistor R4 is connected to the cathode of the input end of the first optocoupler U-1 through the second jumper Jumper2; If the main circuit contactor coil power supply has power, the second I / O port Port2 outputs a low-level signal; if the main circuit contactor coil power supply has no power, the second I / O port Port2 outputs a high-level signal. The mining inverter control chip obtains the status of the main circuit contactor coil power supply through the level signal output by the second I / O port Port2, so as to accurately locate the fault diagnosis.

8. The mine frequency converter safety detection method according to claim 6 is characterized in that: It also includes the step of detecting whether the onboard relay K1 is closed; If the normally open contact of the onboard relay K1 is closed, the third I / O port Prot3 outputs a low-level signal; If the normally open contact of the onboard relay K1 is not closed, the third I / O port Prot3 outputs a high-level signal; The mining inverter control chip obtains the open and closed state of the normally open contact of the onboard relay K1 through the level signal output by the third I / O port Prot3, so as to accurately locate the fault diagnosis.

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