CN220271531U

CN220271531U - Intelligent alternating current insulation monitor

Info

Publication number: CN220271531U
Application number: CN202321617127.9U
Authority: CN
Inventors: 徐学桂; 夏新根
Original assignee: Jiangsu Shangziyi Electrical Equipment Co ltd
Current assignee: Jiangsu Shangziyi Electrical Equipment Co ltd
Priority date: 2023-06-25
Filing date: 2023-06-25
Publication date: 2023-12-29
Anticipated expiration: 2033-06-25

Abstract

The utility model discloses an intelligent alternating current insulation monitor, which belongs to the technical field of intelligent instruments and meters, and comprises an instrument shell, wherein the front surface of the instrument shell is provided with a working mode setting knob, the front surface of the instrument shell is positioned on the upper side of the working mode setting knob and is provided with a working mode indicating LED, and a circuit board is arranged in the inner cavity of the instrument shell.

Description

Intelligent alternating current insulation monitor

Technical Field

The utility model relates to the technical field of intelligent instruments and meters, in particular to an intelligent alternating current insulation monitor.

Background

The marine non-grounding alternating current power grid generally needs to be provided with an alternating current insulation monitor, but the technology used by the traditional products in the market at present generally adopts a fixed direct current detection source to be injected between a terminal to be detected and a grounding terminal so as to monitor the leakage current between a power grid phase line and the ground, thereby monitoring the current power grid insulation resistance value to the ground, and outputting an alarm once the insulation resistance value is lower than a set value.

With the rapid development of electronic technology, a large amount of high-power electric equipment such as a frequency converter is used in a power grid system, a large amount of direct current components and clutter components are arranged in the power grid voltage, the direct current components are not fixed in amplitude, the measurement accuracy of a traditional monitor is directly affected, and the monitor cannot work normally when serious, so that the intelligent alternating current insulation monitor is provided.

Disclosure of Invention

1. Technical problem to be solved

Aiming at the problems existing in the prior art, the utility model aims to provide an intelligent alternating current insulation monitor, which can adopt an adjustable detection source in the process of detecting leakage current between a phase line of a power grid and the ground by utilizing the alternating current insulation monitor, can adapt to various power grids with serious interference, improves the measurement accuracy of the monitor, fully utilizes the resources such as ADC, PWM and the like in a microprocessor, has a simple circuit structure, can judge the positive and negative polarities of the received direct current components once the power grid is interfered by the direct current components, is convenient for a user to optimize the power grid, and can also work in a common mode and meet the requirements of traditional users.

2. Technical proposal

In order to solve the problems, the utility model adopts the following technical scheme.

The utility model provides an intelligent alternating current insulation monitor, includes the instrument shell, the front of instrument shell is equipped with the operating mode setting knob, the instrument shell openly is located the upside of operating mode setting knob and is equipped with operating mode instruction LED, the circuit board is installed to the inner chamber of instrument shell, MCU microprocessor is installed in the front of circuit board, the front of circuit board is equipped with DAC circuit A and DAC circuit B, DAC circuit A and DAC circuit B are located MCU microprocessor's downside, the front of circuit board is equipped with adjustable direct current detection source and sampling circuit, adjustable direct current detection source and sampling circuit are located DAC circuit A and DAC circuit B's left side respectively, electric connection between sampling circuit, adjustable direct current detection source, DAC circuit B, DAC circuit A, operating mode instruction LED, the operating mode setting knob and the MCU microprocessor.

Furthermore, an ADC sampling, a PWM port A and a PWM port B are arranged in the MCU microprocessor, and the PWM port A is positioned between the ADC sampling and the PWM port B.

Further, an indication scale is arranged on the front surface of the instrument shell, and the indication scale is positioned on the lower side of the working mode indication LED.

Further, the upper side that instrument shell inner chamber is located sampling circuit is equipped with alarm relay, the instrument shell openly is equipped with the alarm setting knob in the left side that the mode set up the knob, the instrument shell openly is equipped with alarm LED in the upside that mode indicates LED, electric connection between alarm LED, alarm setting knob, alarm relay and the MCU microprocessor.

Further, the alarm setting knob is provided with an alarm elimination gear.

3. Advantageous effects

Compared with the prior art, the utility model has the advantages that:

in the process of detecting the leakage current between the phase line of the power grid and the ground by using the alternating current insulation monitor, the utility model adopts the adjustable detection source, can adapt to various power grids with serious interference, improves the measurement accuracy of the monitor, fully utilizes the ADC, PWM and other resources in the microprocessor, has simple circuit structure, can judge the positive and negative polarities of the received direct current component once the power grid is interfered by the direct current component, is convenient for users to optimize the power grid, and simultaneously can work in a common mode, and meets the requirements of traditional users.

Drawings

FIG. 1 is a schematic view of the appearance structure of the present utility model;

FIG. 2 is a schematic view of the internal structure of the present utility model;

FIG. 3 is a block diagram of the hardware principles of the present utility model;

FIG. 4 is a block diagram of the main software flow of the present utility model;

fig. 5 is a schematic diagram of the intelligent ac insulation monitor according to the present utility model.

The reference numerals in the figures illustrate:

1. an instrument housing; 2. a working mode setting knob; 3. an operating mode indicating LED; 4. a circuit board; 5. an MCU microprocessor; 501. ADC sampling; 502. a PWM port A; 503. a PWM port B; 6. a DAC circuit A; 7. a DAC circuit B; 8. an adjustable DC detection source; 9. a sampling circuit; 10. pointer header; 11. an indication scale; 12. an alarm relay; 13. an alarm setting knob; 14. and an alarm LED.

Detailed Description

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model; it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments, and that all other embodiments obtained by persons of ordinary skill in the art without making creative efforts based on the embodiments in the present utility model are within the protection scope of the present utility model.

Example 1:

the utility model provides a high-adaptability and high-reliability alternating current insulation monitoring technology which can be applied to marine power grid insulation monitoring instruments, and provides the following detailed technical scheme for achieving the purposes: referring to figure 5 of the drawings in which,

formulas 1 to 3

Equation 4

The conventional technical scheme generally measures the detection current I according to the formula 4 _{Inspection and detection} Size, and R is combined again _{Inspection and detection} Calculating to obtain the leakage resistance value R _{Leakage device} ；

It can be seen that the conventional technical scheme does not consider U ₀ Has great influence on the actual measurement accuracy. In practice, this effect is significant and, in severe cases, even causes the detector to fail.

The proposal provided by the patent considers that in the actual application process of the monitor, the field side is an alternating current power grid, the circuit model of the object to be detected is series connection of a capacitor, an inductor and a voltage source, the circuit diagram is shown in the above diagram, and 3 inspection current values I can be obtained by adjusting the mode of detecting the source voltage _{Check 0} 、I _{Inspection 1} 、I _{Inspection 2} Then according to I _{Check 0} The positive and negative polarities of the values from I _{Inspection 1} 、I _{Inspection 2} In the method, 1 value is selected again and substituted into a corresponding formula, I _{Check 0} The value of (2) is substituted into formula 1, R _{Inspection and detection} The insulation resistance value R to be detected by the detector can be calculated by two formulas for known values _{Leakage device} And outputting an alarm after the value is lower than the set value of the user.

Example 2:

in order to eliminate the influence of the direct current component and the clutter component on the alternating current insulation monitor in the prior art power grid,

referring to fig. 1-4, an intelligent ac insulation monitor, including instrument shell 1, the front of instrument shell 1 is equipped with operating mode setting knob 2, instrument shell 1 openly is located the upside of operating mode setting knob 2 and is equipped with operating mode instruction LED3, circuit board 4 is installed to the inner chamber of instrument shell 1, MCU microprocessor 5 is installed in the front of circuit board 4, the front of circuit board 4 is equipped with DAC circuit A6 and DAC circuit B7, DAC circuit A6 and DAC circuit B7 are located the downside of MCU microprocessor 5, the front of circuit board 4 is equipped with adjustable direct current detection source 8 and sampling circuit 9, adjustable direct current detection source 8 and sampling circuit 9 are located the left side of DAC circuit A6 and DAC circuit B7 respectively, sampling circuit 9, adjustable direct current detection source 8, DAC circuit B7, DAC circuit A6, operating mode instructs LED3, be electrically connected between operating mode setting knob 2 and the MCU microprocessor 5, this scheme can realize utilizing ac insulation monitor to detect the in-process of electric wire netting between phase line and the earth, adopt adjustable detection source can improve each kind of electric netting, the electric netting can receive the electric netting, the electric netting can be easily carried out by the noise of the measuring instrument, the PWM component is fully has been satisfied, the PWM signal level sensor is well-down carried out to the power grid, the user has been judged in the conventional power netting has been reached, the user has measured the user has carried out, the high accuracy has been satisfied, the user has been judged the user has well, and has been convenient, the user has well monitored the user has measured.

Referring to fig. 2-3, an ADC sample 501, a PWM port a502 and a PWM port B503 are provided in the MCU microprocessor 5, the PWM port a502 is located between the ADC sample 501 and the PWM port B503, and by providing the MCU microprocessor 5, the model configuration of the MCU microprocessor 5 preferably adopts the model configuration of STC8H, which makes the overall intelligentization degree of the detector higher, and the circuit structure is simpler.

Referring to fig. 1-3, an indication scale 11 is installed on the front surface of the instrument housing 1, the indication scale 11 is located at the lower side of the working mode indication LED3, and after the leakage current is measured by the monitor, the pointer head 10 can rotate to the corresponding indication scale 11 by setting the pointer head 10 and the indication scale 11, so that the leakage current can be visually displayed.

Referring to fig. 1-3, an alarm relay 12 is disposed on the upper side of the sampling circuit 9 in the inner cavity of the instrument housing 1, an alarm setting knob 13 is disposed on the left side of the operating mode setting knob 2 in the front of the instrument housing 1, an alarm LED14 is disposed on the upper side of the operating mode indicating LED3 in the front of the instrument housing 1, the alarm LED14, the alarm setting knob 13, the alarm relay 12 and the MCU microprocessor 5 are electrically connected, when the calculated insulation resistance is lower than the user set value, the alarm relay 12 works to trigger the alarm LED14 to send out an alarm, the alarm setting knob 13 is provided with an alarm stop, and when the shore power system is a grounding system, the detector will send out false alarm, so that the knob should be adjusted to the stop.

In the utility model, the power supply part of the monitor adopts a transformer step-down mode, two paths of secondary outputs are adopted, one path of secondary outputs passes through two paths of half-bridge rectifying and filtering circuits to form a group of positive and negative power supplies for supplying power to the adjustable voltage source circuit, and the other group of secondary outputs is used as a main working power supply of the whole circuit after passing through a voltage stabilizing chip after passing through full-bridge filtering. The mode of using the transformer is high in reliability and low in cost, isolation between primary and secondary can be achieved, a macro-crystal STC8H series microprocessor is selected as a main control chip by the monitor, internal resources of the chip are fully utilized, the internal 12-bit ADC can meet the sampling of leakage current, DAC output is achieved by utilizing the internal PWM port A502 and the PWM port B503 to match with the DAC circuit A6 and the DAC circuit B7, the control of the adjustable direct current detection source 8 and the output of the pointer gauge outfit 10 are achieved, the working mode setting knob 2 and the alarm value setting knob 13 are read firstly after the monitor is electrified, the software flow chart is shown in fig. 3, and when the self-detection mode is TEST, if a calibration plate is connected, a full scale calibration subroutine is entered, otherwise, the alarm relay 12 is attracted, and the alarm LED14 is lightened. In the intelligent mode, different detection source voltages are sequentially output to measure different leakage currents, and U can be eliminated by referring to formulas 1-3 ₀ And (3) calculating the insulation resistance value of the power grid, and outputting a relay dry contact alarm signal and an LED indication signal once the insulation resistance is lower than a user set value. In the normal mode, the detecting source outputs a fixed detecting voltage, measures the leakage current, calculates the insulation resistance value, judges whether the insulation resistance value is lower than the set value, the monitor alarm setting knob 13 is also provided with an alarm stop, when the ship uses shore power, the shore power system is a grounding system, and the detector can give out false alarm, so the ship uses shore powerThe knob should be transferred to this shelves, compare with prior art, this scheme can be realized utilizing exchanging insulating monitor to carry out the in-process that detects to the electric wire netting phase line between with the earth leakage current, adopt adjustable detection source, can adapt to various electric wire netting that receive the interference seriously, the measurement accuracy of monitor has been improved, the inside ADC of make full use of microprocessor, resources such as PWM, circuit structure is simple, once the electric wire netting has received the interference of direct current component, the positive and negative polarity of direct current component that receives can be judged to the monitor, convenience of customers optimizes the electric wire netting, the monitor can also work in ordinary mode simultaneously, traditional user's demand has been considered.

The above description is only of the preferred embodiments of the present utility model; the scope of the utility model is not limited in this respect. Any person skilled in the art, within the technical scope of the present disclosure, may apply to the present utility model, and the technical solution and the improvement thereof are all covered by the protection scope of the present utility model.

Claims

1. The utility model provides an intelligent alternating current insulation monitor, includes instrument housing (1), its characterized in that: the utility model discloses a portable electronic device, including instrument shell (1), circuit board (4), MCU microprocessor (5), DAC circuit A (6) and DAC circuit B (7) are equipped with in the front of instrument shell (1), instrument shell (1) openly is located the upside of operating mode setting knob (2) and is equipped with operating mode instruction LED (3), circuit board (4) are installed in the inner chamber of instrument shell (1), MCU microprocessor (5) are installed in the front of circuit board (4), DAC circuit A (6) and DAC circuit B (7) are located the downside of MCU microprocessor (5), adjustable direct current detection source (8) and sampling circuit (9) are equipped with in the front of circuit board (4), adjustable direct current detection source (8) and sampling circuit (9) are located the left side of DAC circuit A (6) and DAC circuit B (7) respectively, sampling circuit (9), adjustable direct current detection source (8), DAC circuit A (6), operating mode instruction LED (3), operating mode are set for between electric connection between knob (2) and the MCU microprocessor (5).

2. The intelligent ac insulation monitor as set forth in claim 1, wherein: an ADC sample (501), a PWM port A (502) and a PWM port B (503) are arranged in the MCU microprocessor (5), and the PWM port A (502) is positioned between the ADC sample (501) and the PWM port B (503).

3. The intelligent ac insulation monitor as set forth in claim 1, wherein: an indicating scale (11) is arranged on the front surface of the instrument shell (1), and the indicating scale (11) is positioned on the lower side of the working mode indicating LED (3).

4. The intelligent ac insulation monitor as set forth in claim 1, wherein: the utility model discloses a measuring instrument, including instrument shell (1), operating mode instruction LED (3), instrument shell (1), alarm relay (12) are equipped with in the upside that inner chamber of instrument shell (1) is located sampling circuit (9), instrument shell (1) openly is equipped with alarm setting knob (13) in the left side that operating mode set up knob (2), instrument shell (1) openly is equipped with alarm LED (14) in the upside that operating mode instructs LED (3), electric connection between alarm LED (14), alarm setting knob (13), alarm relay (12) and MCU microprocessor (5).

5. The intelligent ac insulation monitor as set forth in claim 4, wherein: the alarm setting knob (13) is provided with an alarm elimination gear.