Frequency converter capacitor bank pre-charging device

Abstract

The utility model belongs to the field of electric control equipment, particularly relates to a frequency converter capacitor bank pre-charging device, and aims to solve the problem that the conventional capacitor bank pre-charging device is poor in protection effect and portability in use. The pre-charging device comprises a shell and a pre-charging circuit, the shell comprises an operation interface; the pre-charging circuit comprises a three-phase rectification voltage regulation module, a potentiometer, a resistance-capacitance absorption plate, an output end, a switching power supply voltage regulation module, a fan, an alternating current contactor and a current limiting resistor. According to the utility model, alternating current is converted into adjustable direct current to charge the capacitor bank of the frequency converter, the sensitive adjustment of current can be realized, the precision and the reliability are improved, the working temperature can be controlled within 40 DEG C, the reliable operation of the device is ensured, the circuit structure is simple, the size of the device is small, the use is convenient, and the device is safe and reliable.

Description

Background Art

[0002] With the continuous development of drilling equipment, high-power inverters have been widely used in the oil drilling industry. The capacitor group inside the inverter is an important energy storage component. According to the characteristics of the capacitor group, the capacitor group is prone to be in a power-deficient state if it is out of use for a long time. When the capacitor group is in a power-deficient state, the moment the power is turned on again and the circuit is closed, the charging current of the capacitor in the circuit will surge instantly, causing an overcurrent phenomenon. In severe cases, it will cause the capacitor to explode, which will not only cause direct damage to equipment and personnel, but also delay the normal drilling progress and have a certain impact on underground safety. Taking Siemens capacitor group 6SY7000-0AD88 as an example, the unit price of a group is more than 40,000 yuan, causing certain economic losses. In order to avoid this phenomenon, it is necessary to develop a portable capacitor group pre-charging device. Utility Model Content

[0003] In order to solve the above-mentioned problems in the prior art, that is, the problems that the existing capacitor bank pre-charging device has poor protection effect and portability when used, the utility model provides a frequency converter capacitor bank pre-charging device, the device comprising:

[0004] housing and pre-charge circuit;

[0005] The housing comprises: an operation interface;

[0006] The pre-charging circuit comprises: a three-phase rectifier voltage regulating module, a potentiometer, a resistor-capacitor absorption board, an output end, a switch power supply to the voltage regulating module, a fan, an AC contactor and a current limiting resistor.

[0007] In some preferred implementations, the specific structure of the pre-charging circuit is:

[0008] The three-phase rectifier and voltage regulator module comprises an L1 terminal, an L2 terminal and an L3 terminal, wherein the L1 terminal, the L2 terminal and the L3 terminal are respectively connected to the R phase, the S phase and the T phase of the potentiometer through the corresponding first contactor, the first fuse and the second contactor; wherein the L1 terminal is also connected to the first terminal of the switching power supply through the first fuse;

[0009] The switching power supply to the voltage regulating module comprises a first end of the switching power supply to the voltage regulating module, a second end of the switching power supply to the voltage regulating module, a third end of the switching power supply to the voltage regulating module and a fourth end of the switching power supply to the voltage regulating module; the second end of the switching power supply to the voltage regulating module is connected to the N line; the third end of the switching power supply to the voltage regulating module and the fourth end of the switching power supply to the voltage regulating module are connected to the potentiometer;

[0010] The potentiometer, including the R phase, S phase and T phase of the potentiometer, is connected to the RC absorption board;

[0011] The output end includes an output positive electrode and an output negative electrode, the output positive electrode and the output negative electrode are connected to the RC absorption plate; the output positive electrode is connected to the positive electrode of the potentiometer through an ammeter and a second fuse in sequence; the output negative electrode is connected to the negative electrode of the potentiometer through the second fuse and a current limiting resistor; wherein a diode is connected between the positive electrode of the potentiometer and the current limiting resistor and the second fuse, and the positive electrode of the diode is one end close to the current limiting resistor; a voltmeter is connected between the output positive electrode and the output negative electrode;

[0012] The first end of the switch power supply to the voltage regulating module is connected to the positive pole of the fan through a contactor, and the negative pole of the fan is connected to the N line through a contactor;

[0013] The first end of the switch power supply to the voltage regulating module is also connected to the N line through a first branch and a second branch connected in parallel.

[0014] In some preferred embodiments, the first branch and the second branch have the same structure;

[0015] The first branch includes: a current transformer TA, a start button QA and an AC contactor connected in sequence from the first end of the switch power supply to the voltage regulating module in the direction of the N line;

[0016] The start button QA is connected in parallel with a contactor; the AC contactor is connected in parallel with an indicator light HL.

[0017] In some preferred embodiments, the first fuse is a 10A fuse, and the second fuse is a 6A fuse.

[0018] In some preferred embodiments, the device further comprises a heat dissipation fan disposed on two sides of the operating interface of the housing.

[0019] In some preferred embodiments, thermal conductive silicone grease is provided between the heat dissipation fan and the three-phase rectification and voltage regulation module.

[0020] In some preferred implementations, the potentiometer is a SXTY-ZL-30A thyristor module from CAXW.

[0021] Beneficial effects of the utility model:

[0022] (1) The inverter capacitor group pre-charging device of the utility model is controlled by a circuit breaker and connected to a fuse to prevent equipment overload and short circuit, and can convert 220V AC power into 24V DC power to achieve adjustable voltage and safe charging. The real-time voltage can be displayed through a voltmeter and an ammeter. A current-limiting resistor is connected in series to the DC output end to limit the maximum output current of the device, thereby protecting the safety of the inverter capacitor group during charging. A resistor-capacitor absorption board is installed between the rectifier input power supply and the DC output power supply to effectively suppress the voltage oscillation and impact current generated at the moment of high-voltage operation, so that the high-frequency oscillation impact current is rapidly attenuated, reducing the impact on the load equipment. The KM1 AC contactor controls the start and stop of the cooling fan. The internal heat of the device is discharged in time to ensure that the pre-charging device works stably and has reliable performance.

[0023] (2) The inverter capacitor group pre-charging device of the utility model realizes the conversion of alternating current into adjustable direct current to charge the inverter capacitor group, and can realize sensitive adjustment of current, with improved accuracy and reliability, and can ensure that the working temperature is controlled within 40°C, ensuring reliable operation of the device, with a simple circuit structure, small device size, easy use, safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0025] Figure 1 It is a connection diagram of a pre-charging circuit in an embodiment of the utility model. DETAILED DESCRIPTION

[0026] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It is also necessary to explain that, for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings.

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] In order to more clearly explain the utility model inverter capacitor bank pre-charging device, the following is combined with Figure 1 Each part in the embodiment of the utility model is described in detail.

[0029] The inverter capacitor bank pre-charging device of the first embodiment of the utility model comprises a housing and a pre-charging circuit; each component is described in detail as follows:

[0030] The housing comprises: an operation interface; the operation interface comprises an ammeter, a voltmeter and an indicator light HL.

[0031] The pre-charging circuit comprises: a three-phase rectifier voltage regulating module, a potentiometer, a resistor-capacitor absorption board, an output end, a switch power supply to the voltage regulating module, a fan, an AC contactor and a current limiting resistor.

[0032] In this embodiment, the specific structure of the pre-charging circuit is:

[0033] The three-phase rectifier and voltage regulator module comprises an L1 terminal, an L2 terminal and an L3 terminal, wherein the L1 terminal, the L2 terminal and the L3 terminal are respectively connected to the R phase, the S phase and the T phase of the potentiometer through the corresponding first contactor, the first fuse and the second contactor; wherein the L1 terminal is also connected to the first terminal of the switching power supply through the first fuse;

[0034] The potentiometer is a SXTY-ZL-30A thyristor module from caxw.

[0035] The switching power supply to the voltage regulating module comprises a first end of the switching power supply to the voltage regulating module, a second end of the switching power supply to the voltage regulating module, a third end of the switching power supply to the voltage regulating module and a fourth end of the switching power supply to the voltage regulating module; the second end of the switching power supply to the voltage regulating module is connected to the N line; the third end of the switching power supply to the voltage regulating module and the fourth end of the switching power supply to the voltage regulating module are connected to the potentiometer;

[0036] A switching power supply is used to provide DC control power to the device.

[0037] The potentiometer, including the R phase, S phase and T phase of the potentiometer, is connected to the RC absorption board;

[0038] The output end includes a positive electrode and a negative electrode, and the positive electrode and the negative electrode are connected to a resistor-capacitor absorption plate; the positive electrode of the output end is connected to the positive electrode of the potentiometer through an ammeter and a second fuse in sequence; the negative electrode of the output end is connected to the negative electrode of the potentiometer through the second fuse and a current limiting resistor; wherein a diode is connected between the positive electrode of the potentiometer and the current limiting resistor and the second fuse, and the positive electrode of the diode is one end close to the current limiting resistor; a voltmeter is connected between the positive electrode of the output end and the negative electrode of the output end.

[0039] In this embodiment, thermal conductive silicone grease is provided between the heat dissipation fan and the three-phase rectification and voltage regulation module.

[0040] In this embodiment, the first fuse is a 10A fuse, and the second fuse is a 6A fuse.

[0041] The first end of the switch power supply to the voltage regulating module is connected to the positive pole of the fan through a contactor, and the negative pole of the fan is connected to the N line through a contactor;

[0042] The first end of the switch power supply to the voltage regulating module is also connected to the N line through a first branch and a second branch connected in parallel.

[0043] In this embodiment, the first branch and the second branch have the same structure;

[0044] The first branch includes: a current transformer TA, a start button QA and an AC contactor connected in sequence from the first end of the switch power supply to the voltage regulating module in the direction of the N line;

[0045] The start button QA is connected in parallel with a contactor; the AC contactor is connected in parallel with an indicator light HL.

[0046] In this embodiment, the device further includes a heat dissipation fan disposed on two sides of the operating interface of the housing.

[0047] Thermal conductive silicone grease is arranged between the heat dissipation fan and the three-phase rectifying and voltage regulating module.

[0048] The cooling fan and thermal grease are used to ensure that the temperature of the three-phase rectifier module does not exceed 75°C during operation;

[0049] The working principle of a pre-charging device for a frequency converter capacitor bank according to the second embodiment of the utility model includes:

[0050] The three-phase rectifier and voltage regulator module in this embodiment converts the AC power supply into DC power for input. The utility model can connect 380V voltage, and the DC can reach 537V, which meets the requirements of the site. Under normal circumstances, a 220V switching power supply is used as the switching power supply to provide control current to the voltage regulator module.

[0051] A resistor-capacitor absorption board is also installed between the three-phase rectifier and the potentiometer, which can effectively suppress the voltage oscillation and impact current generated at the moment of high-voltage operation, make the high-frequency oscillation impact current decay rapidly, and reduce the impact on the load equipment.

[0052] The switch power supply connected between the three-phase rectifier module and the potentiometer provides control power to the voltage regulator module, and the potentiometer is used to control the voltage output of the rectifier module to achieve the function of voltage adjustment. The connection and disconnection of the three-phase rectifier and voltage regulator module are controlled by the AC contactor.

[0053] At work, the AC contactor controls the on and off of the equipment power supply, and is equipped with a fuse inside to prevent the equipment from overload and short circuit.

[0054] After the potentiometer completes the conversion from AC to DC, the maximum output current is also limited by the current limiting resistor, thereby protecting the safety of the inverter capacitor bank during charging and preventing misoperation.

[0055] An ammeter and a voltmeter are set at the output end to observe the working voltage and current in real time.

[0056] The power supply of the device is controlled by a circuit breaker, and a fuse is connected to the bottom to prevent the equipment from overloading and short circuiting to ensure the safety of electricity use. The switching power supply converts 220V AC into 24V DC, provides control power to the voltage regulating module, uses a potentiometer to control the voltage output of the rectifier module, realizes the function of adjustable voltage, and displays the real-time voltage through a voltmeter. The AC contactor KM controls the on and off of the power supply of the equipment. A current limiting resistor is connected in series to the DC output end to limit the maximum output current of the device, thereby protecting the safety of the inverter capacitor group during charging. Between the rectifier input power supply and the DC output power supply, a resistor-capacitor absorption board is installed to effectively suppress the voltage oscillation and impact current generated at the moment of high-voltage operation, so that the high-frequency oscillation impact current is rapidly attenuated, reducing the impact on the load equipment. The KM1 AC contactor controls the start and stop of the cooling fan. The internal heat of the device is discharged in time to ensure that the pre-charging device works stably and has reliable performance.

[0057] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the system described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0058] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the storage device and processing device described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0059] The terms "first", "second", etc. are used to distinguish similar objects rather than to describe or indicate a particular order or sequence.

[0060] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0061] So far, the technical solution of the utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the utility model is obviously not limited to these specific embodiments. Without departing from the principle of the utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the utility model.

Claims

1. A pre-charging device for a frequency converter capacitor bank, characterized in that: The device comprises: housing and pre-charge circuit; The housing comprises: an operation interface; The pre-charging circuit comprises: a three-phase rectifier voltage regulating module, a potentiometer, a resistor-capacitor absorption board, an output end, a switch power supply to the voltage regulating module, a fan, an AC contactor and a current limiting resistor.

2. A frequency converter capacitor bank pre-charging device according to claim 1, characterized in that: The specific structure of the pre-charge circuit is: The three-phase rectifier and voltage regulator module comprises an L1 terminal, an L2 terminal and an L3 terminal, wherein the L1 terminal, the L2 terminal and the L3 terminal are respectively connected to the R phase, the S phase and the T phase of the potentiometer through the corresponding first contactor, the first fuse and the second contactor; wherein the L1 terminal is also connected to the first terminal of the switching power supply through the first fuse; The switching power supply to the voltage regulating module comprises a first end of the switching power supply to the voltage regulating module, a second end of the switching power supply to the voltage regulating module, a third end of the switching power supply to the voltage regulating module and a fourth end of the switching power supply to the voltage regulating module; the second end of the switching power supply to the voltage regulating module is connected to the N line; the third end of the switching power supply to the voltage regulating module and the fourth end of the switching power supply to the voltage regulating module are connected to the potentiometer; The potentiometer, including the R phase, S phase and T phase of the potentiometer, is connected to the RC absorption board; The output end includes an output positive electrode and an output negative electrode, the output positive electrode and the output negative electrode are connected to the RC absorption plate; the output positive electrode is connected to the positive electrode of the potentiometer through an ammeter and a second fuse in sequence; the output negative electrode is connected to the negative electrode of the potentiometer through the second fuse and a current limiting resistor; wherein a diode is connected between the positive electrode of the potentiometer and the current limiting resistor and the second fuse, and the positive electrode of the diode is one end close to the current limiting resistor; a voltmeter is connected between the output positive electrode and the output negative electrode; The first end of the switch power supply to the voltage regulating module is connected to the positive pole of the fan through a contactor, and the negative pole of the fan is connected to the N line through a contactor; The first end of the switch power supply to the voltage regulating module is also connected to the N line through a first branch and a second branch connected in parallel.

3. A pre-charging device for a frequency converter capacitor bank according to claim 2, characterized in that: The first branch and the second branch have the same structure; The first branch includes: a current transformer TA, a start button QA and an AC contactor connected in sequence from the first end of the switch power supply to the voltage regulating module in the direction of the N line; The start button QA is connected in parallel with a contactor; the AC contactor is connected in parallel with an indicator light HL.

4. A pre-charging device for a frequency converter capacitor bank according to claim 3, characterized in that: The first fuse is a 10A fuse, and the second fuse is a 6A fuse.

5. The inverter capacitor bank pre-charging device according to claim 1, characterized in that: The device also includes a heat dissipation fan, which is arranged on two sides of the operating interface of the shell.

6. A pre-charging device for a frequency converter capacitor bank according to claim 5, characterized in that: Thermal conductive silicone grease is arranged between the heat dissipation fan and the three-phase rectifying and voltage regulating module.

7. The inverter capacitor bank pre-charging device according to claim 1, characterized in that: The potentiometer is a SXTY-ZL-30A thyristor module from caxw.

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