Anti-condensation control device for intelligent electrical cabinet

Abstract

The utility model discloses an anti-condensation control device for an intelligent electrical cabinet, and the device comprises a PT1000 thermal resistor which is fixed on a housing of the intelligent electrical cabinet; one side of the bridge circuit is connected with a first terminal of the PT1000 thermal resistor; a first input end of the operational amplifier is connected with the other side of the bridge circuit, and a second input end of the operational amplifier is connected with a second terminal of the PT1000 thermal resistor; wherein a second terminal of the PT1000 thermal resistor is a sampling end; and the input end of the AD sampling circuit is connected with the output end of the operational amplifier, and the AD sampling circuit is used for outputting a temperature measurement result. The analog detection quantity of the PT1000 thermal resistor is amplified through the operational amplifier, and the analog detection quantity is output as a digital temperature value through the AD sampling circuit, so that the sensitivity of the anti-condensation control device for the intelligent electrical cabinet is improved from a temperature detection link, and the anti-condensation effect of the anti-condensation control device for the intelligent electrical cabinet is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to an intelligent electrical cabinet anti-condensation control device. Background Art

[0002] The existing anti-condensation solution adopts mechanical ventilation, air conditioning cooling, dehumidifiers and other methods to meet the requirements of electrical cabinets during most periods of the year. However, during certain special periods, due to sudden changes in outdoor climate (mainly changes in air temperature, humidity and dust concentration), condensation will occur on electrical components in cable trenches and switch cabinets or electrical panel cabinet structures, causing the insulation performance of the equipment to be greatly reduced or even broken down, causing equipment corrosion and accelerating equipment aging. At the same time, partial discharge may also occur, damaging components, making equipment more prone to failure, increasing repair costs, and reducing the probability of safe operation of the power grid.

[0003] According to the main causes of condensation, the condensation in the cable trench can be effectively prevented from occurring from two aspects: reducing moisture ingress and preventing temperature differences. The existing anti-condensation solution for intelligent electrical cabinets still has deficiencies in temperature detection sensitivity, which in turn affects the static characteristics of the sensor, so measures must be taken to reduce or eliminate the interference caused by temperature changes. Utility Model Content

[0004] In view of this, an embodiment of the utility model provides an anti-condensation control device for an intelligent electrical cabinet to solve the problem that the temperature detection of the anti-condensation solution for the intelligent electrical cabinet in the prior art is not sensitive enough.

[0005] The present invention provides an intelligent electrical cabinet anti-condensation control device, comprising:

[0006] PT1000 thermal resistor, fixed on the casing of the intelligent electrical cabinet;

[0007] A bridge circuit, one side of which is connected to the first terminal of the PT1000 thermal resistor;

[0008] An operational amplifier, wherein a first input terminal thereof is connected to the other side of the bridge circuit, and a second input terminal thereof is connected to a second terminal of the PT1000 thermal resistor; wherein the second terminal of the PT1000 thermal resistor is a sampling terminal;

[0009] The AD sampling circuit has an input end connected to the output end of the operational amplifier, and the AD sampling circuit is used to output the temperature measurement result.

[0010] Optionally, the PT1000 thermal resistor is connected to the bridge circuit via a three-wire connection; wherein the third terminal of the PT1000 thermal resistor is grounded.

[0011] Optionally, the bridge circuit comprises:

[0012] A first resistor, one end of which is connected to the second terminal of the PT1000 thermal resistor;

[0013] a second resistor, one end of which is connected to the other end of the first resistor;

[0014] A third resistor, one end of which is grounded with the third terminal of the PT1000 thermal resistor;

[0015] A 3V voltage source is connected between the first resistor and the second resistor; the other end of the second resistor and the other end of the third resistor are connected to the first input end of the operational amplifier.

[0016] Optionally, it also includes:

[0017] A first capacitor has one end connected between the other end of the second resistor / the other end of the third resistor and the first input end of the operational amplifier, and the other end of the first capacitor is grounded; wherein the first capacitor is used for filtering.

[0018] Optionally, the operational amplifier uses an instrumentation amplifier of model INA826AIDR.

[0019] Optionally, it also includes:

[0020] A second capacitor has one end connected between the second terminal of the PT1000 thermal resistor and the second input terminal of the operational amplifier, and the other end of the second capacitor is grounded; the second capacitor is used for filtering.

[0021] Optionally, it also includes:

[0022] The adjustment resistor is connected between pins 2 and 3 of the operational amplifier to adjust the op amp multiple.

[0023] Optionally, it also includes:

[0024] 3.3V voltage source, connected to pin 8 of the operational amplifier;

[0025] A third capacitor has one end connected between pin 8 of the operational amplifier and the 3.3V voltage source, and the other end connected to the ground.

[0026] Optionally, the input end of the AD sampling circuit is connected to pin 7 of the operational amplifier.

[0027] Beneficial effects of the utility model:

[0028] The embodiment of the utility model provides an intelligent electrical cabinet anti-condensation control device, which adopts a PT1000 thermal resistor, a bridge circuit and an operational amplifier. The analog detection quantity of the PT1000 thermal resistor is amplified by the operational amplifier, and the temperature value is output as a digital quantity through an AD sampling circuit. Then, logic control is performed for a specific sampling temperature through a controller, thereby improving the sensitivity of the intelligent electrical cabinet anti-condensation control device from the link of temperature detection, thereby improving the anti-condensation effect of the intelligent electrical cabinet anti-condensation control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0030] Figure 1 A circuit diagram of an intelligent electrical cabinet anti-condensation control device in an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0032] like Figure 1 As shown, an embodiment of the utility model provides an anti-condensation control device for an intelligent electrical cabinet, including a PT1000 thermal resistor, a bridge circuit, an operational amplifier and an AD sampling circuit, wherein the PT1000 thermal resistor is fixed on the housing of the intelligent electrical cabinet; one side of the bridge circuit is connected to the first terminal of the PT1000 thermal resistor; the first input end of the operational amplifier is connected to the other side of the bridge circuit, and the second input end thereof is connected to the second terminal of the PT1000 thermal resistor; wherein the second terminal of the PT1000 thermal resistor is a sampling end; the input end of the AD sampling circuit is connected to the output end of the operational amplifier, and the AD sampling circuit is used to output the temperature measurement result.

[0033] As an optional implementation, the PT1000 thermal resistor is connected to the bridge circuit via a three-wire connection; wherein the third terminal of the PT1000 thermal resistor is grounded.

[0034] In this embodiment, the PT1000 thermal resistor is connected to the bridge circuit via a jumper J12. Pin 1 of the jumper J12 is connected to the sampling end of the PT1000 thermal resistor, pin 2 of the jumper J12 is connected to the bridge circuit, and pin 3 of the jumper J12 is grounded.

[0035] As an optional implementation, the bridge circuit includes:

[0036] A first resistor R21, one end of which is connected to the second terminal of the PT1000 thermal resistor;

[0037] A second resistor R53, one end of which is connected to the other end of the first resistor;

[0038] A third resistor R55, one end of which is grounded with the third terminal of the PT1000 thermal resistor;

[0039] A 3V voltage source is connected between the first resistor R21 and the second resistor R53; the other end of the second resistor R53 and the other end of the third resistor R55 are connected to the first input end of the operational amplifier.

[0040] As an optional implementation, it also includes:

[0041] The first capacitor C55 has one end connected between the other end of the second resistor R53 / the other end of the third resistor R55 and the first input terminal (IN-pin) of the operational amplifier, and the other end of the first capacitor C55 is grounded; wherein the first capacitor C55 is used for filtering.

[0042] As an optional implementation, the operational amplifier uses an instrumentation amplifier of model INA826AIDR.

[0043] As an optional implementation, it also includes:

[0044] The second capacitor C56 has one end connected between the second terminal of the PT1000 thermal resistor and the second input terminal (IN+ pin) of the operational amplifier, and the other end of the second capacitor C56 is grounded; the second capacitor C56 is used for filtering.

[0045] As an optional implementation, it also includes:

[0046] The adjusting resistor R54 is connected between pin 2 (RG pin) and pin 3 (PG pin) of the operational amplifier to adjust the operational amplifier multiple.

[0047] In this embodiment, the voltage difference output by the bridge is amplified proportionally by adjusting the resistance value of resistor R54 of the operational amplifier, so that the amplified voltage is just within the full scale of AD sampling.

[0048] As an optional implementation, it also includes:

[0049] 3.3V voltage source, connected to pin 8 (V+ pin) of the operational amplifier;

[0050] The third capacitor C53 has one end connected between the pin 8 of the operational amplifier and the 3.3V voltage source, and the other end connected to the ground.

[0051] As an optional implementation, the fourth resistor R56 between the second input terminal (pin 4, IN+ pin) and pin 7 of the operational amplifier is not mounted.

[0052] As an optional implementation, the input end of the AD sampling circuit is connected to the pin 7 of the operational amplifier. The REF pin of the operational amplifier is grounded.

[0053] As an optional implementation, the pin 7 of the operational amplifier is also connected to one end of a fifth resistor R62, and the other end of the fifth resistor R62 is connected to an AD sampling port of the MCU.

[0054] In a specific embodiment, the test point TP is set between the pin 7 of the operational amplifier and the resistor R62.

[0055] The embodiment of the utility model provides an intelligent electrical cabinet anti-condensation control device, which adopts a PT1000 thermal resistor, a bridge circuit and an operational amplifier. The analog detection quantity of the PT1000 thermal resistor is amplified by the operational amplifier, and the temperature value is output as a digital quantity through an AD sampling circuit. Then, logic control is performed for a specific sampling temperature through a controller, thereby improving the sensitivity of the intelligent electrical cabinet anti-condensation control device from the link of temperature detection, thereby improving the anti-condensation effect of the intelligent electrical cabinet anti-condensation control device.

[0056] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An intelligent electrical cabinet anti-condensation control device, characterized in that: include: PT1000 thermal resistor, fixed on the casing of the intelligent electrical cabinet; A bridge circuit, one side of which is connected to the first terminal of the PT1000 thermal resistor; An operational amplifier, wherein a first input terminal thereof is connected to the other side of the bridge circuit, and a second input terminal thereof is connected to a second terminal of the PT1000 thermal resistor; wherein the second terminal of the PT1000 thermal resistor is a sampling terminal; The AD sampling circuit has an input end connected to the output end of the operational amplifier, and the AD sampling circuit is used to output the temperature measurement result.

2. The intelligent electrical cabinet anti-condensation control device according to claim 1, characterized in that: The PT1000 thermal resistor is connected to the bridge circuit via a three-wire connection; wherein the third terminal of the PT1000 thermal resistor is grounded.

3. The intelligent electrical cabinet anti-condensation control device according to claim 2, characterized in that: The bridge circuit comprises: A first resistor, one end of which is connected to the second terminal of the PT1000 thermal resistor; a second resistor, one end of which is connected to the other end of the first resistor; a third resistor, one end of which is grounded with the third terminal of the PT1000 thermal resistor; A 3V voltage source is connected between the first resistor and the second resistor; the other end of the second resistor and the other end of the third resistor are connected to the first input end of the operational amplifier.

4. The intelligent electrical cabinet anti-condensation control device according to claim 3, characterized in that: Also includes: A first capacitor, one end of which is connected between the other end of the second resistor / the other end of the third resistor and the first input end of the operational amplifier, and the other end of the first capacitor is grounded; wherein the first capacitor is used for filtering.

5. The intelligent electrical cabinet anti-condensation control device according to claim 1, characterized in that: The operational amplifier is an instrument amplifier of model INA826AIDR.

6. The intelligent electrical cabinet anti-condensation control device according to claim 1, characterized in that: Also includes: A second capacitor, one end of which is connected between the second terminal of the PT1000 thermal resistor and the second input terminal of the operational amplifier, and the other end of the second capacitor is grounded; The second capacitor is used for filtering.

7. The intelligent electrical cabinet anti-condensation control device according to claim 5, characterized in that: Also includes: The adjusting resistor is connected between the pin 2 and the pin 3 of the operational amplifier and is used to adjust the operational amplifier multiple.

8. The intelligent electrical cabinet anti-condensation control device according to claim 5, characterized in that: Also includes: A 3.3V voltage source is connected to pin 8 of the operational amplifier; A third capacitor has one end connected between pin 8 of the operational amplifier and the 3.3V voltage source, and the other end connected to the ground.

9. The intelligent electrical cabinet anti-condensation control device according to claim 1, characterized in that: The input end of the AD sampling circuit is connected to the pin 7 of the operational amplifier.

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