A RLC comprehensive high voltage impedance leakage locking protection device for mines

Abstract

The present invention proposes a RLC comprehensive high-voltage impedance leakage locking protection device for mining, comprising a reversible contactor KM, a motor M, a current transformer T, a controller PLC, a current detection module CA, a comprehensive protection module EL, a leakage locking detection module GG, a leakage transmission module DA and a grounding terminal GND; the present invention has the beneficial effects of isolating through an A / D circuit after filtering, voltage reduction and voltage stabilization, setting dual relays and dual power supplies, enhancing the reliability and safety of the device, preventing leakage faults from occurring, and effectively protecting the safe operation of the system.

Description

Technical Field

[0001] The invention relates to the field of electromechanics, and in particular to an RLC comprehensive high-voltage impedance leakage locking protection device for mining. Background Art

[0002] In my country's primary energy structure, coal will be the main energy source for a long time. Advanced coal production process depends on advanced coal mining machinery and equipment. Mining explosion-proof electrical appliances, as special coal mining machinery and equipment involving personal and equipment safety, occupy an important position in the national economy. With the continuous development of modern mines, mining explosion-proof electrical equipment products are gradually developing towards intelligence, large capacity and combination, and microelectronics technology has also begun to be applied in mining explosion-proof electrical equipment products.

[0003] The following are the common types of leakage faults in coal mine motors and their power supply lines: First, the insulation resistance of the motor and its power supply line decreases due to moisture, and the ground leakage current increases, making the motor casing and the electrical casing charged; second, the insulation of the motor and its power supply line is grounded (metallic grounding or arc grounding) due to aging, mechanical damage or voltage breakdown; third, the exposed part of the live body of the motor and its power supply line (such as mechanical damage or maintenance) is directly touched by personnel or through conductive objects such as tools, resulting in an electric shock accident (accidental and temporary) with one phase being grounded.

[0004] If leakage faults are not promptly protected, especially in coal mines, there will be serious consequences. It may lead to danger to human life, explosion of gas and coal dust, premature ignition of detonators, and burning of one-phase winding of the motor in neutral point grounding systems and neutral point ungrounding systems with large distributed capacitance. Therefore, leakage protection must be carried out for coal mine motors and their power supply lines, especially underground.

[0005] In my country's coal mine underground power supply system, the neutral point of the transformer is strictly prohibited from being grounded. Usually, in each independent system, a leakage relay is uniformly set up to achieve leakage protection. However, this method will inevitably cause a power outage in the entire system if leakage occurs at any point. In order to better identify the leakage point and shorten the time to deal with the accident, a common practice is to add a leakage lock in the switch. From a safety perspective, the importance of leakage lock is no less than leakage protection.

[0006] The leakage lockout detection circuit is connected when the switch is not working. Usually, it is put into operation at the same time as the main contacts of the switch are disconnected. However, since there is still an arc connected when the main contacts are disconnected, or the motor will have residual magnetic potential within 1-3 seconds due to continued rotation, if the leakage lockout detection circuit is put into operation at the same time, then the above-mentioned high voltage will enter the detection circuit, causing unnecessary damage. For this reason, a delay relay is usually added to delay the input of the leakage detection circuit, usually with a delay time of 2-3 seconds; or the detection circuit is designed with a self-protection function, which can suppress or block the high voltage when the high voltage enters, thereby protecting its own circuit components from damage. Both methods are used, and the latter can save a delay relay, but has higher requirements for circuit design. Therefore, the leakage of the high-voltage switch has always been in an imperfect state. When encountering various faults, when high voltage and high current enter, many related accessories are damaged. Once such a fault occurs, the switch will be paralyzed and unable to operate, affecting the underground production and personal equipment safety. Summary of the invention

[0007] The present invention proposes a method to solve the above-mentioned problems in the prior art.

[0008] The technical solution of the present invention is achieved in this way:

[0009] A RLC comprehensive high-voltage impedance leakage locking protection device for mines, a RLC comprehensive high-voltage impedance leakage locking protection device for mines, comprising a reversible contactor KM, a motor M, a current transformer T, a controller PLC, a current detection module CA, a comprehensive protection module EL, a leakage locking detection module GG, a leakage transmission module DA and a grounding terminal GND;

[0010] The leakage lock detection module GG, the leakage transmission module DA, the grounding terminal GND and the three-phase power line form a leakage detection circuit;

[0011] The leakage lockout detection module GG includes an inductor L, a relay J1, a relay J2, a resistor R1, a capacitor C, a resistor R2 and a voltage regulator tube D;

[0012] The relay J1 and the relay J2 have coils and contacts;

[0013] The coils of relay J1 and relay J2 are connected in parallel and electrically connected to the controller PLC;

[0014] The first end of the inductor L is connected to one phase of the three-phase power line, and the tail end of the inductor L is connected to the first end of the contact of the relay J1;

[0015] The tail end of the relay J1 contact is connected to the head end of the relay J2 contact;

[0016] The tail end of relay J2 is connected to the head end of resistor R1;

[0017] The tail end of the resistor R1 is connected to the head end of the resistor R2;

[0018] The tail end of the resistor R1 is connected to the head end of the capacitor C;

[0019] The tail end of the capacitor C is connected to the ground terminal GND;

[0020] The tail end of the resistor R2 is connected to the head end of the voltage regulator tube D, and the tail end of the voltage regulator tube D is connected to the ground terminal GND;

[0021] The tail end of the resistor R2 is connected to the leakage current transmitter module DA;

[0022] The leakage current transmission module DA is electrically connected to the comprehensive protection module EL;

[0023] The integrated protection module EL is electrically connected to the controller PLC;

[0024] Preferably, in the RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention, the three-phase power line in the main circuit is connected to the motor M through the reversible contactor KM and the current transformer T;

[0025] The controller PLC is electrically connected to the reversible contactor KM to control the start and stop of the motor M;

[0026] The current transformer T is electrically connected to the current detection module CA, and is used to detect whether there is current in the circuit and the current magnitude, and then feed back the signal to the current detection module CA;

[0027] The current detection module CA is electrically connected to the integrated protection module EL, and the signal is sent to the integrated protection module EL after being processed by the current detection module CA;

[0028] Furthermore, the RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention further includes a power supply AD1 and a power supply AD2, and the power supplies AD1 and AD2 are used to supply power to the leakage transmission module DA;

[0029] Preferably, in the RLC comprehensive high-voltage impedance leakage locking protection device for mining described in the present invention, both the current detection module CA and the leakage transmission module DA adopt A / D conversion circuits.

[0030] The beneficial effects of the present invention are:

[0031] The RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention is isolated by an A / D circuit after filtering, voltage reduction and voltage stabilization, and is provided with double relays and double power supplies, so as to enhance the reliability and safety of the device, prevent leakage faults from occurring, and effectively protect the safe operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

[0033] Figure 1 The present invention is a circuit diagram of an embodiment of the RLC comprehensive high-voltage impedance leakage locking protection device for mining. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Embodiment 1 is used in a 3.3kv system for mining;

[0036] like Figure 1 As shown, the RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention comprises a reversible contactor KM, a motor M, a current transformer T, a controller PLC, a current detection module CA, a comprehensive protection module EL, a leakage locking detection module GG, a leakage transmission module DA and a grounding terminal GND;

[0037] The three-phase power line in the main circuit passes through the reversible contactor KM, through the current transformer T and is connected to the motor M;

[0038] The controller PLC is electrically connected to the reversible contactor KM to control the start and stop of the motor M;

[0039] The current transformer T is electrically connected to the current detection module CA, and is used to detect whether there is current in the circuit and the current magnitude, and then feed back the signal to the current detection module CA;

[0040] The current detection module CA is electrically connected to the integrated protection module EL, and the signal is sent to the integrated protection module EL after being processed by the current detection module CA;

[0041] The leakage lock detection module GG, the leakage transmission module DA, the grounding terminal GND and the three-phase power line form a leakage detection circuit;

[0042] The leakage lockout detection module GG includes an inductor L, a relay J1, a relay J2, a resistor R1, a capacitor C, a resistor R2 and a voltage regulator tube D;

[0043] The relay J1 and the relay J2 have coils and contacts;

[0044] The coils of relay J1 and relay J2 are connected in parallel and electrically connected to the controller PLC;

[0045] The first end of the inductor L is connected to one phase of the three-phase power line, and the tail end of the inductor L is connected to the first end of the contact of the relay J1;

[0046] The tail end of the relay J1 contact is connected to the head end of the relay J2 contact;

[0047] The tail end of relay J2 is connected to the head end of resistor R1;

[0048] The tail end of the resistor R1 is connected to the head end of the resistor R2;

[0049] The tail end of the resistor R1 is connected to the head end of the capacitor C;

[0050] The tail end of the capacitor C is connected to the ground terminal GND;

[0051] The tail end of the resistor R2 is connected to the head end of the voltage regulator tube D, and the tail end of the voltage regulator tube D is connected to the ground terminal GND;

[0052] The tail end of the resistor R2 is connected to the leakage current transmitter module DA;

[0053] The leakage current transmission module DA is electrically connected to the comprehensive protection module EL;

[0054] The integrated protection module EL is electrically connected to the controller PLC;

[0055] The working principle of the RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention is as follows:

[0056] Because the detected object of the RLC comprehensive high-voltage impedance leakage lockout protection device for mining of the present invention includes a three-phase motor M, and the three phases through the stator winding are connected, there is no need for three-phase detection, and only one phase is required; for the leakage lockout installed in the feeder switch, three-phase detection should still be considered;

[0057] Before the motor M starts, the current transformer T senses the three-phase power line to detect whether there is current and the current size in the line, and then feeds back the analog signal to the current detection module CA. The analog signal is processed by the current detection module CA and converted into a digital signal, which is sent to the integrated protection module EL.

[0058] When there is no current in the three-phase power line, the integrated protection module EL sends a signal to the controller PLC, and the controller PLC energizes the coils of relays J1 and J2, and the contacts of J1 and J2 are closed, connecting the leakage lockout detection module GG and the leakage transmission module DA. The leakage lockout detection module GG inputs the analog signal into the leakage transmission module DA, measures the insulation resistance value of the main circuit to the ground, and then converts it into a digital signal and sends it to the integrated protection module EL; if the insulation resistance value to the ground is greater than the specified value, it means that the insulation of the main circuit is good, and the integrated protection module EL sends a signal The controller PLC is supplied with power to the coils of relays J1 and J2, thereby cutting off the leakage lockout detection function before the motor M starts, and then controlling the reversible contactor KM to be turned on, and the motor M starts; after the motor M stops, the leakage lockout detection function is put back into operation, and the cycle continues; if the insulation resistance to ground is less than the specified value, it means that the insulation of the main circuit does not meet the standard, and at this time the comprehensive protection module EL sends a signal to the controller PLC, and the controller PLC controls the contactor KM to prohibit closing, thereby prohibiting the motor M from starting again, and realizing leakage lockout to ensure production safety;

[0059] If AC high voltage enters the leakage detection circuit, the inductor L, resistor R1, resistor R2 and capacitor C in the leakage lock detection module GG will reduce the AC high voltage through filtering and voltage reduction functions to ensure safety; the voltage regulator D will further limit the reduced AC high voltage signal to below the specified voltage value, thereby further ensuring the safety of each device in the leakage detection circuit;

[0060] The purpose of setting two relays in the leakage lockout detection module GG is to further ensure that the leakage detection circuit can be reliably disconnected when the motor M starts running, to prevent AC high voltage from entering the leakage detection circuit and damaging the device;

[0061] Furthermore, the RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention further comprises a power supply AD1 and a power supply AD2, and the power supplies AD1 and AD2 are used to supply power to the leakage transmitter module DA; the use of dual power supplies is to further ensure the working reliability of the leakage transmitter module DA;

[0062] The current detection module CA and the leakage transmission module DA both adopt A / D conversion circuits, which have good stability, are not susceptible to noise interference like analog circuits, and have high reliability.

[0063] The RLC comprehensive high-voltage impedance leakage locking protection device for mining of the present invention is isolated by an A / D circuit after filtering, voltage reduction and voltage stabilization, and is provided with double relays and double power supplies, so as to enhance the reliability and safety of the device, prevent leakage faults from occurring, and effectively protect the safe operation of the system.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A RLC comprehensive high-voltage impedance leakage locking protection device for mining, characterized in that: It includes a reversible contactor KM, a motor M, a current transformer T, a controller PLC, a current detection module CA, a comprehensive protection module EL, a leakage lock detection module GG, a leakage transmission module DA, a grounding terminal GND, a power supply AD1 and a power supply AD2; The leakage lock detection module GG, the leakage transmission module DA, the grounding terminal GND and the three-phase power line form a leakage detection circuit; The leakage lockout detection module GG includes an inductor L, a relay J1, a relay J2, a resistor R1, a capacitor C, a resistor R2 and a voltage regulator tube D; The relay J1 and the relay J2 have coils and contacts; The coils of relay J1 and relay J2 are connected in parallel and electrically connected to the controller PLC; The first end of the inductor L is connected to one phase of the three-phase power line, and the tail end of the inductor L is connected to the first end of the contact of the relay J1; The tail end of the relay J1 contact is connected to the head end of the relay J2 contact; The tail end of relay J2 is connected to the head end of resistor R1; The tail end of the resistor R1 is connected to the head end of the resistor R2; The tail end of the resistor R1 is connected to the head end of the capacitor C; The tail end of the capacitor C is connected to the ground terminal GND; The tail end of the resistor R2 is connected to the head end of the voltage regulator tube D, and the tail end of the voltage regulator tube D is connected to the ground terminal GND; The tail end of the resistor R2 is connected to the leakage current transmitter module DA; The leakage current transmission module DA is electrically connected to the comprehensive protection module EL; The integrated protection module EL is electrically connected to the controller PLC; The three-phase power line in the main circuit passes through the reversible contactor KM, through the current transformer T and is connected to the motor M; The controller PLC is electrically connected to the reversible contactor KM to control the start and stop of the motor M; The current transformer T is electrically connected to the current detection module CA, and is used to detect whether there is current in the circuit and the current magnitude, and then feed back the signal to the current detection module CA; The current detection module CA is electrically connected to the integrated protection module EL, and the signal is sent to the integrated protection module EL after being processed by the current detection module CA; Power supplies AD1 and AD2 are used to supply power to the leakage transmitter module DA; The current detection module CA and the leakage transmission module DA both adopt A / D conversion circuits.

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