Direct-current power supply bipolar grounding protection circuit and method

Abstract

The embodiment of the invention discloses a bipolar grounding protection circuit and method for a direct-current power supply. The direct-current power supply bipolar grounding protection circuit comprises a voltage dividing module, a sampling module, a data processing module and a protection module, the first end of the voltage dividing module is connected with the positive electrode of the direct-current power source, the second end of the voltage dividing module and the first end of the sampling module are both connected with the first end of the data processing module, the second end of the sampling module and the third end of the voltage dividing module are both connected with the second end of the data processing module, and the fourth end of the voltage dividing module is connected with the negative electrode of the direct-current power source. The output end of the data processing module is connected with the protection module; the protection module is connected with the direct-current power supply; the connection point of the second end of the voltage dividing module and the first end of the sampling module is a grounding detection point; the data processing module is used for collecting voltages at two ends of the sampling module, determining whether the DC power supply is grounded according to the voltages at two ends of the sampling module, and controlling the protection module to give an alarm or cut off power supply of the DC power supply when the DC power supply is grounded.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the direct current power supply protection technical field, in particular to a direct current power supply bipolarity ground protection circuit and method. BACKGROUND

[0002] At present, the positive and negative poles of the direct current power supply ground protection generally adopts the leakage current detection method, that is, the leakage current detection meter is erected between the positive and negative poles of the direct current power supply and the external ground potential, when the leakage current detection meter detects the leakage current, the positive pole of the direct current power supply is determined to be grounded, so as to inform the related device of protecting the direct current power supply to execute the protection action. However, the leakage current detection of the positive and negative poles of the direct current power supply has the problems of low detection precision, low detection reliability, poor detection coverage, poor universality and poor detection foresight. SUMMARY

[0003] The embodiment of the present application provides a direct current power supply bipolarity ground protection circuit and method, so as to improve the detection precision, detection reliability, detection coverage, detection universality and detection foresight of the direct current power supply bipolarity ground, and timely and effectively realize the protection of the direct current power supply bipolarity ground.

[0004] In a first aspect, the embodiment of the present application provides a direct current power supply bipolarity ground protection circuit, which comprises a voltage division module, a sampling module, a data processing module and a protection module.

[0005] The first end of the voltage division module is connected with the positive pole of the direct current power supply, the second end of the voltage division module and the first end of the sampling module are connected with the first end of the data processing module, the second end of the sampling module and the third end of the voltage division module are connected with the second end of the data processing module, the fourth end of the voltage division module is connected with the negative pole of the direct current power supply, the output end of the data processing module is connected with the protection module, and the protection module is connected with the direct current power supply.

[0006] The connection point of the second end of the voltage division module and the first end of the sampling module is a ground detection point.

[0007] The data processing module is used for collecting the voltage between the two ends of the sampling module, confirming whether the direct current power supply is grounded according to the voltage between the two ends of the sampling module, and controlling the protection module to alarm or cut off the power supply of the direct current power supply when the direct current power supply is grounded.

[0008] Optionally, the voltage division module comprises a first voltage division resistor and a second voltage division resistor.

[0009] The first end of the first voltage dividing resistor is the first end of the voltage dividing module, the second end of the first voltage dividing resistor is the second end of the voltage dividing module, the first end of the second voltage dividing resistor is the third end of the voltage dividing module, and the second end of the second voltage dividing resistor is the fourth end of the voltage dividing module.

[0010] Optionally, the sampling module comprises a sampling resistor and a voltage stabilizing capacitor.

[0011] The first end of the sampling resistor and the first end of the voltage stabilizing capacitor are connected and serve as the first end of the sampling module, and the second end of the sampling resistor and the second end of the voltage stabilizing capacitor are connected and serve as the second end of the sampling module.

[0012] Optionally, the data processing module comprises a signal conditioning unit and a data processing unit.

[0013] The first end of the signal conditioning unit serves as the first end of the data processing module, the second end of the signal conditioning unit serves as the second end of the data processing module, the first output end of the signal conditioning unit is connected to the input end of the data processing unit, and the output end of the data processing unit serves as the output end of the data processing module.

[0014] Optionally, the protection module comprises an alarm unit, a display alarm unit, and a direct current power supply control unit.

[0015] The alarm unit, the display alarm unit, and the direct current power supply control unit are connected to the data processing module, and the direct current power supply control unit is connected to the direct current power supply.

[0016] In a second aspect, an embodiment of the present application further provides a direct current power supply bipolarity grounding protection method applied to the direct current power supply bipolarity grounding protection circuit provided by any of the embodiments of the present application.

[0017] The method comprises:

[0018] The data processing module collects the voltage across the sampling module.

[0019] The data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module.

[0020] The data processing module controls the protection module to alarm or cut off the direct current power supply when the direct current power supply is grounded.

[0021] Optionally, the data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module, and the confirming comprises:

[0022] If the voltage across the sampling module equals a first sampling voltage threshold, the DC power supply is not grounded;

[0023] If the voltage across the sampling module is greater than or equal to a second sampling voltage threshold, the positive pole of the DC power supply is grounded;

[0024] If the voltage across the sampling module is less than or equal to a third sampling voltage threshold, the negative pole of the DC power supply is grounded.

[0025] Optionally, the voltage dividing module comprises a first voltage dividing resistor and a second voltage dividing resistor;

[0026] The first end of the first voltage dividing resistor is the first end of the voltage dividing module, the second end of the first voltage dividing resistor is the second end of the voltage dividing module, the first end of the second voltage dividing resistor is the third end of the voltage dividing module, and the second end of the second voltage dividing resistor is the fourth end of the voltage dividing module;

[0027] The sampling module comprises a sampling resistor; the first end of the sampling resistor is the first end of the sampling module, and the second end of the sampling resistor is the second end of the sampling module;

[0028] The first sampling voltage threshold U s is:

[0029]

[0030] wherein R1 is the resistance of the first voltage dividing resistor, R2 is the resistance of the second voltage dividing resistor, voltage dividing resistor, R s is the resistance of the sampling resistor, and U P is the voltage of the DC power supply.

[0031] Optionally, the second sampling voltage threshold U′ S is:

[0032]

[0033] wherein R P is the equivalent insulation resistance of the positive pole of the DC power supply to ground.

[0034] Optionally, the second sampling voltage threshold U′ s is:

[0035]

[0036] wherein R g is the equivalent insulation resistance of the negative pole of the DC power supply to ground.

[0037] The embodiment of the present application divides the voltage of the direct current power supply through the voltage dividing module, so that the voltage between the sampling module is within the voltage range that can be collected by the data processing module. The data processing module confirms whether the direct current power supply is grounded based on the voltage between the sampling module, judges the degree of decline of insulation between the direct current power supply and the external ground potential, and controls the protection module to alarm or cut off the direct current power supply according to the degree of decline of insulation between the direct current power supply and the external ground potential. Therefore, the detection accuracy, detection reliability, detection coverage, detection universality and detection foresight of the bipolar grounding of the direct current power supply can be improved, so as to realize the protection of the bipolar grounding of the direct current power supply in time. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Figure 1 A structure diagram of a leakage current detection direct current power supply positive electrode grounding provided by the prior art;

[0040] Figure 2 A structure diagram of a direct current power supply bipolar grounding protection circuit provided by the embodiment of the present application;

[0041] Figure 3 A structure diagram of a direct current power supply bipolar grounding protection equivalent circuit when the positive electrode of the direct current power supply is grounded provided by the embodiment of the present application;

[0042] Figure 4 A structure diagram of a direct current power supply bipolar grounding protection equivalent circuit when the negative electrode of the direct current power supply is grounded provided by the embodiment of the present application;

[0043] Figure 5 Another structure diagram of a direct current power supply bipolar grounding protection circuit provided by the embodiment of the present application;

[0044] Figure 6 A flowchart of a direct current power supply bipolar grounding protection method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts should fall within the scope of the present application.

[0046] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0047] The safety protection focus of the DC power supply circuit is the external electrical isolation, that is, the insulation of the positive terminal and the negative terminal of the DC power supply circuit to the external ground potential. When the insulation resistance of any one of the two poles of the DC power supply circuit to the ground tends to infinity, the DC power supply circuit is in an external electrical isolation state. When the insulation resistance of any one of the two poles of the DC power supply circuit to the ground decreases and is lower than a certain critical value, the external electrical isolation of the DC power supply circuit is no longer reliable. At this time, if the insulation failure (direct grounding) of the DC power supply circuit to the ground cannot be found in time, the DC power supply circuit will malfunction, be damaged, or even cause an accident.

[0048] At present, the ground protection of the positive terminal and the negative terminal of the DC power supply circuit generally adopts a leakage current detection method. Figure 1 A structure diagram for detecting the ground of the positive terminal of the DC power supply by the leakage current detection method provided by the prior art is shown in FIG. 1. Figure 1 As shown in FIG. 1, the resistance R' is the equivalent insulation resistance of the positive terminal of the DC power supply to the external ground potential. When the equivalent insulation resistance of the positive terminal of the DC power supply to the external ground potential decreases, the leakage current detector can detect a larger leakage current, and then trigger the ground protection action of the positive terminal of the DC power supply. Alternatively, the leakage current detector detects the leakage current in the normal state. When the positive terminal of the DC power supply is grounded short-circuited, the current detected by the leakage current detector will decrease, so that it is inferred that the abnormal grounding of the DC power supply occurs, and then the ground protection action of the positive terminal of the DC power supply is triggered.

[0049] However, the above leakage current detection method has the problems of low detection accuracy, low detection reliability, poor detection coverage, poor detection universality and poor detection foresight, and the following will be described in detail the problems of low detection accuracy, low detection reliability, poor detection coverage, poor detection universality and poor detection foresight of the above leakage current detection method:

[0050] 1) Low detection accuracy and low detection reliability. The detection of leakage current itself is relatively difficult, and the weaker the current, the more difficult it is to ensure the detection accuracy. Weak current detection is easily affected by the environment and electrical life, so that the detection accuracy cannot be kept stable for a long time and needs to be calibrated and calibrated regularly. In addition, the leakage current of the positive and negative poles of the DC power supply to the external ground potential is weak current. If the leakage current of the positive and negative poles of the DC power supply to the external ground potential becomes strong, it means that the positive and negative poles of the DC power supply have been grounded and have caused a major failure, and the detection reliability is low.

[0051] 2. Poor detection coverage. The detection effect of the leakage current detection method is good at the central grounding point or near the ground potential position. Therefore, the leakage current detection method has poor overall coverage for long straight DC power supply circuits. If the insulation of the DC power supply circuit is damaged far from the leakage current detection point, effective detection cannot be achieved, so multiple leakage current monitoring points need to be set for long straight and multiple grounding insulation weak points of the DC power supply circuit.

[0052] 3. Poor universality. The leakage current detection method has certain threshold requirements for the voltage level of the DC power supply circuit. The leakage current detected by the leakage current detection method is more weak in the case of low DC power supply voltage, and it is difficult to adapt to detection, so only DC power supply circuits higher than a certain voltage level can use the leakage current detection method. However, there is a great risk in detecting the leakage current of high-voltage DC power supply, and complex isolation and protection must be carried out.

[0053] 4. Poor foresight. As described above, the leakage current itself can only be effectively detected when it reaches a certain magnitude, but when the leakage current changes are detected, the insulation resistance of the DC power supply circuit problem polarity to the external ground potential is already very low or even grounded. Since the reaction time of the positive or negative pole grounding fault of the DC power supply circuit is very short, it is impossible to avoid the occurrence of the fault in time.

[0054] In view of the above problems, the embodiment of the present application provides a DC power supply bipolar grounding protection circuit, which can improve the detection accuracy, detection reliability, detection coverage, detection universality and detection foresight of the DC power supply bipolar grounding, and protect the DC power supply bipolar grounding in time. Figure 2 The structure diagram of the DC power supply bipolar grounding protection circuit provided by the embodiment of the present application is shown in the figure, Figure 2As shown, the direct current power supply bipolarity ground protection circuit includes a voltage division module 110, a sampling module 120, a data processing module 130, and a protection module 140.

[0055] A first end of the voltage division module 110 is connected with a positive pole POWER+ of the direct current power supply, a second end of the voltage division module 110 and a first end of the sampling module 120 are both connected with a first end of the data processing module 130, a second end of the sampling module 120 and a third end of the voltage division module 110 are both connected with a second end of the data processing module 130, a fourth end of the voltage division module 110 is connected with a negative pole POWER- of the direct current power supply, an output end of the data processing module 130 is connected with the protection module 140, and the protection module 140 is connected with the direct current power supply.

[0056] A connection point of the second end of the voltage division module 110 and the first end of the sampling module 120 is a ground detection point.

[0057] The data processing module 130 is configured to collect a voltage between the sampling module 120, and confirm whether the direct current power supply is grounded according to the voltage between the sampling module 120, and control the protection module 140 to alarm or cut off the direct current power supply when the direct current power supply is grounded.

[0058] The voltage division module 110 can divide the voltage of the direct current power supply, so that the voltage between the sampling module 120 is within a voltage range that can be collected by the data processing module 130, to ensure the accuracy of the data processing module 130 collecting the voltage between the sampling module 120. The data processing module 130 can process the collected voltage between the sampling module 120 (for example, signal conditioning, amplification, analog-to-digital conversion, etc.), and analyze the voltage between the sampling module 120, to deduce the insulation state between the current direct current power supply and the external ground potential, and then confirm whether the direct current power supply will be grounded. If the data processing module 130 determines that the direct current power supply will be grounded, the protection module 140 will be controlled to alarm or cut off the direct current power supply according to the degree of insulation between the direct current power supply and the external ground potential.

[0059] Specifically, when the positive or negative pole of the direct current power supply is grounded, the insulation resistance of the positive or negative pole of the direct current power supply equivalent to ground changes, thereby causing the proportion of the voltage division module 110 to divide the voltage of the direct current voltage to change, and further causing the voltage across the sampling module 120 to change. Thus, the present scheme is simpler and more reliable than the existing leakage current detection technology, improves the detection accuracy and detection reliability of the direct current power supply bipolar grounding, improves the detection coverage of the direct current power supply bipolar grounding, improves the universality of the direct current power supply bipolar grounding detection, and improves the foresight of the direct current power supply bipolar grounding protection.

[0060] The voltage across the sampling module 120 is within the voltage range that can be collected by the data processing module 130, the data processing module 130 confirms whether the direct current power supply is grounded based on the voltage across the sampling module 120, judges the degree of decline of the insulation between the direct current power supply and the external ground potential, and controls the protection module 140 to alarm or cut off the direct current power supply according to the degree of decline of the insulation between the direct current power supply and the external ground potential. Thus, the detection accuracy, detection reliability, detection coverage, detection universality and detection foresight of the direct current power supply bipolar grounding can be improved to realize timely protection of the direct current power supply bipolar grounding.

[0061] On the basis of the above-mentioned embodiments, optionally, with reference to Figure 2 The voltage division module 110 includes a first voltage division resistor R1 and a second voltage division resistor R2; a first end of the first voltage division resistor R1 is a first end of the voltage division module 110, a second end of the first voltage division resistor R1 is a second end of the voltage division module 110, a first end of the second voltage division resistor R2 is a third end of the voltage division module 110, and a second end of the second voltage division resistor R2 is a fourth end of the voltage division module 110.

[0062] The sampling module includes a sampling resistor R s and a voltage stabilizing capacitor C;

[0063] The first end of the sampling resistor R s and the first end of the voltage stabilizing capacitor C are connected and serve as a first end of the sampling module 120, and the second end of the sampling resistor R sThe second end of the sampling resistor R and the second end of the voltage stabilizing capacitor C are connected and serve as the second end of the sampling module 120.

[0064] Specifically, the first end of the first voltage dividing resistor R1 is connected with the positive pole POWER+ of the direct current power supply, the second end of the first voltage dividing resistor R1 is connected with the sampling resistor R s The first end of the sampling resistor R and the first end of the voltage stabilizing capacitor C are connected, and the sampling resistor R s The second end of the sampling resistor R and the second end of the voltage stabilizing capacitor C are both connected with the first end of the second voltage dividing resistor R2, and the second end of the second voltage dividing resistor R2 is connected with the negative pole POWER- of the direct current power supply. The connection point of the second end of the first voltage dividing resistor R1 and the first end of the sampling resistor R s is the sampling point T of the external ground potential.

[0065] When the direct current power supply is not grounded, the first voltage dividing resistor R1, the sampling resistor R s and the second voltage dividing resistor R2 are connected in series, at this time, the voltage U s across the sampling resistor R s is:

[0066] It should be noted that: in order to adapt to different direct current power supply voltage level occasions, by designing and adjusting the first voltage dividing resistor R1, the sampling resistor R s and the second voltage dividing resistor R2, it can be ensured that no matter what the voltage level of the direct current power supply loop is, the sampling voltage U s on the sampling resistor R s is within the reliable and safe sampling requirement range of the data processing module 130.

[0067] Figure 3 The structure of the equivalent circuit of the direct current power supply bipolarity ground protection when the positive pole of the direct current power supply is grounded is provided for the embodiment of the application, as shown in Figure 3 When the positive pole POWER+ of the direct current power supply is grounded, that is, the equivalent insulation resistance of the positive pole of the direct current power supply to the external ground potential decreases, the equivalent insulation resistance R p of the positive pole POWER+ of the direct current power supply to the ground is connected in parallel with the first voltage dividing resistor R1, and then connected in series with the sampling resistor R s and the second voltage dividing resistor R2, at this time, the voltage U s across the sampling resistor R s is:

[0068] The data processing module 130 monitors the voltage across the sampling resistor R sThe voltage across the sampling resistor R1 can be used to calculate the decrease of the equivalent insulation resistance between the positive pole of the DC power supply and the external ground potential. Thus, the preset equivalent insulation resistance between the positive pole of the DC power supply and the external ground potential can be used to obtain the alarm threshold sampling voltage U' according to the above formula s As long as the actual sampling voltage Us≥U' s , the positive pole of the DC power supply is grounded, and the data processing module 130 controls the protection module 140 to alarm or cut off the power supply of the DC power supply.

[0069] In summary, as long as the insulation resistance between the positive pole of the DC power supply and the ground is lower than R p , an alarm can be given. Thus, the direct grounding of the positive pole of the DC power supply can be avoided, and the direct grounding fault of the positive pole of the DC power supply is predicted, which reserves sufficient time to solve the impending grounding fault of the positive pole of the DC power supply.

[0070] Figure 4 The equivalent circuit structure of the bipolar grounding protection of the DC power supply when the negative pole of the DC power supply is grounded is provided for the embodiment of the application, as shown in Figure 4 When the negative pole POWER- of the DC power supply is grounded, that is, the equivalent insulation resistance between the negative pole of the DC power supply and the external ground potential decreases, the equivalent insulation resistance R g between the negative pole POWER- of the DC power supply and the ground is connected in parallel with the series circuit of the sampling resistor R s and the second voltage dividing resistor R2 and is connected in series with the first voltage dividing resistor R1. At this time, the voltage U s across the sampling resistor R1 is: s

[0071] The data processing module 130 can monitor the voltage across the sampling resistor R s when the negative pole of the DC power supply is grounded. Thus, the decrease of the equivalent insulation resistance between the negative pole of the DC power supply and the external ground potential can be calculated. Thus, the preset equivalent insulation resistance R g between the negative pole of the DC power supply and the external ground potential can be used to obtain the alarm threshold sampling voltage U' s ′ according to the above formula. As long as the actual sampling voltage Us≤U' s ′, the negative pole of the DC power supply is grounded, and the data processing module 130 controls the protection module 140 to alarm or cut off the power supply of the DC power supply.

[0072] In summary, as long as the insulation resistance between the negative pole of the DC power supply and the ground is lower than R g , an alarm is given. Thus, the direct grounding of the negative pole of the DC power supply can be avoided, and the direct grounding fault of the negative pole of the DC power supply is predicted, which reserves sufficient time to solve the impending grounding fault of the negative pole of the DC power supply.

[0073] ​On the basis of the above-mentioned embodiments, optionally, Figure 5 Another structure schematic diagram of a direct current power supply bipolarity grounding protection circuit provided by the embodiment of the present application is shown in the figure. Figure 5 As shown in the figure, the data processing module 130 comprises a signal conditioning unit 131 and a data processing unit 132; the first end of the signal conditioning unit 131 is the first end of the data processing module 130, the second end of the signal conditioning unit 131 is the second end of the data processing module 130, the output end of the signal conditioning unit 131 is connected with the input end of the data processing unit 132, and the output end of the data processing unit 132 is the output end of the data processing module 130.

[0074] The protection module 140 comprises an alarm unit 141, a display alarm unit 142 and a direct current power supply control unit 143; the alarm unit 141, the display alarm unit 142 and the direct current power supply control unit 143 are connected with the data processing module 130, and the direct current power supply control unit 143 is connected with the direct current power supply.

[0075] The signal conditioning unit 131 can perform conditioning, amplification and digital-analog conversion on the voltage across the sampling resistor R s to improve the accuracy of the collected voltage data. The data processing unit 132 can analyze the voltage data across the sampling resistor R s processed by the signal conditioning unit 131 to deduce the insulation state between the current power supply and the external ground potential, and then confirm whether the direct current power supply will be grounded. The data processing unit 132 is used to determine whether the direct current power supply is grounded, which will control the alarm unit 141 to alarm, the display alarm unit 142 to alarm and the direct current power supply control unit 143 to cut off the direct current power supply according to the degree of decline of the insulation between the direct current power supply and the external ground potential. For example, when the degree of decline of the insulation between the direct current power supply and the external ground potential is relatively small, the data processing unit 132 will control the alarm unit 141 to alarm, and the voltage across the sampling resistor R s is transmitted to the display alarm unit 142 for alarm display; when the degree of decline of the insulation between the direct current power supply and the external ground potential is relatively large, the data processing unit 132 will control the alarm unit 141 to alarm, the voltage across the sampling resistor R s is transmitted to the display alarm unit 142 for alarm display, and the direct current power supply control unit 143 is controlled to cut off the direct current power supply quickly.

[0076] The embodiment of the present application also provides a direct current power supply bipolarity grounding protection method, Figure 6 A flowchart of a direct current power supply bipolarity grounding protection method provided by the embodiment of the present application is shown in the figure. Figure 6As shown, the direct current power supply bipolarity grounding protection method is applied to the direct current power supply bipolarity grounding protection circuit provided by any embodiment of the application.

[0077] The method specifically comprises:

[0078] S110, the data processing module collects the voltage across the sampling module.

[0079] S120, the data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module.

[0080] S130, the data processing module controls the protection module to alarm or cut off the direct current power supply when the direct current power supply is grounded.

[0081] The embodiment of the application confirms whether the direct current power supply is grounded based on the voltage across the sampling module by the data processing module, judges the degree of decline of insulation between the direct current power supply and the external ground potential, and controls the protection module to alarm or cut off the direct current power supply according to the degree of decline of insulation between the direct current power supply and the external ground potential. Therefore, the detection precision, detection reliability, detection coverage, detection universality and detection foresight of the direct current power supply bipolarity grounding can be improved, and the protection of the direct current power supply bipolarity grounding can be realized in time.

[0082] On the basis of the above embodiment, optionally, the voltage dividing module comprises a first voltage dividing resistor and a second voltage dividing resistor; a first end of the first voltage dividing resistor serves as a first end of the voltage dividing module, a second end of the first voltage dividing resistor serves as a second end of the voltage dividing module, a first end of the second voltage dividing resistor serves as a third end of the voltage dividing module, and a second end of the second voltage dividing resistor serves as a fourth end of the voltage dividing module; the sampling module comprises a sampling resistor; a first end of the sampling resistor serves as a first end of the sampling module, and a second end of the sampling resistor serves as a second end of the sampling module.

[0083] The data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module, and comprises:

[0084] If the voltage across the sampling module is equal to the first sampling voltage threshold, the direct current power supply is not grounded.

[0085] The first sampling voltage threshold U s is:

[0086]

[0087] The first voltage dividing resistor R1 has a resistance value, the second voltage dividing resistor R2 has a resistance value, the voltage dividing resistor R has a resistance value, the sampling resistor R has a resistance value, the first sampling voltage threshold U s is the voltage of the direct current power supply. P

[0088] ​If the voltage across the sampling module is greater than or equal to the second sampling voltage threshold, the positive pole of the DC power supply is grounded.

[0089] wherein the second sampling voltage threshold U' S ′ is:

[0090]

[0091] wherein R P is the equivalent insulation resistance value of the positive pole of the DC power supply to ground.

[0092] If the voltage across the sampling module is less than or equal to the third sampling voltage threshold, the negative pole of the DC power supply is grounded.

[0093] wherein the second sampling voltage threshold U' s is:

[0094]

[0095] wherein R g is the equivalent insulation resistance value of the negative pole of the DC power supply to ground.

[0096] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, the steps described in the present application can be performed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

[0097] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A direct current power supply bipolar ground protection circuit, characterized by, The direct current power supply bipolarity grounding protection circuit comprises a voltage dividing module, a sampling module, a data processing module and a protection module. The first end of the voltage dividing module is connected with the positive pole of a direct current power supply, the second end of the voltage dividing module and the first end of the sampling module are both connected with the first end of the data processing module, the second end of the sampling module and the third end of the voltage dividing module are both connected with the second end of the data processing module, the fourth end of the voltage dividing module is connected with the negative pole of the direct current power supply, the output end of the data processing module is connected with the protection module, and the protection module is connected with the direct current power supply. The connection point of the second end of the voltage dividing module and the first end of the sampling module is a grounding detection point. The data processing module is used for collecting the voltage across the sampling module, and confirming whether the direct current power supply is grounded according to the voltage across the sampling module, and controlling the protection module to alarm or cut off the power supply of the direct current power supply when the direct current power supply is grounded.

2. The DC power supply bipolar ground protection circuit of claim 1, wherein, The voltage dividing module comprises a first voltage dividing resistor and a second voltage dividing resistor. The first end of the first voltage dividing resistor serves as the first end of the voltage dividing module, the second end of the first voltage dividing resistor serves as the second end of the voltage dividing module, the first end of the second voltage dividing resistor serves as the third end of the voltage dividing module, and the second end of the second voltage dividing resistor serves as the fourth end of the voltage dividing module.

3. The DC power supply bipolar ground protection circuit of claim 1, wherein, The sampling module comprises a sampling resistor and a voltage stabilizing capacitor. The first end of the sampling resistor and the first end of the voltage stabilizing capacitor are connected and serve as the first end of the sampling module, and the second end of the sampling resistor and the second end of the voltage stabilizing capacitor are connected and serve as the second end of the sampling module.

4. The DC power supply bipolar ground protection circuit of claim 1, wherein, The data processing module comprises a signal conditioning unit and a data processing unit. The first end of the signal conditioning unit serves as the first end of the data processing module, the second end of the signal conditioning unit serves as the second end of the data processing module, the first output end of the signal conditioning unit is connected with the input end of the data processing unit, and the output end of the data processing unit serves as the output end of the data processing module.

5. The DC power supply bipolar ground protection circuit of claim 1, wherein, The protection module comprises an alarm unit, a display alarm unit and a direct current power supply control unit. The alarm unit, the display alarm unit and the direct current power supply control unit are all connected with the data processing module, and the direct current power supply control unit is connected with the direct current power supply.

6. A direct current power supply bipolar ground protection method, characterized by, The direct current power supply bipolarity grounding protection circuit is applied to any one of claims 1-5. The method comprises: The data processing module collects the voltage across the sampling module. The data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module. The data processing module controls the protection module to alarm or cut off the power supply of the direct current power supply when the direct current power supply is grounded.

7. The method of claim 6, wherein the DC power supply bipolar ground protection method is characterized by, The data processing module confirms whether the direct current power supply is grounded according to the voltage across the sampling module, which comprises: If the voltage across the sampling module is equal to a first sampling voltage threshold, the direct current power supply is not grounded. If the voltage across the sampling module is greater than or equal to a second sampling voltage threshold, the positive pole of the direct current power supply is grounded. If the voltage across the sampling module is less than or equal to a third sampling voltage threshold, the negative pole of the direct current power supply is grounded.

8. The method of claim 7, wherein the DC power supply bipolar ground protection method is characterized by, The voltage dividing module comprises a first voltage dividing resistor and a second voltage dividing resistor. The first end of the first voltage dividing resistor is the first end of the voltage dividing module, the second end of the first voltage dividing resistor is the second end of the voltage dividing module, the first end of the second voltage dividing resistor is the third end of the voltage dividing module, and the second end of the second voltage dividing resistor is the fourth end of the voltage dividing module. The sampling module comprises a sampling resistor, the first end of the sampling resistor is the first end of the sampling module, and the second end of the sampling resistor is the second end of the sampling module. The first sampling voltage threshold U s is: Wherein, R1 is the resistance of the first voltage dividing resistor, R2 is the resistance of the second voltage dividing resistor, voltage dividing resistor, R s is the resistance of the sampling resistor, U P is the voltage of the direct current power supply.

9. The method of claim 8, wherein the DC power supply bipolar ground protection method is characterized by, The second sampling voltage threshold U' S ′ is: wherein R P is the equivalent insulation resistance value of the positive terminal of the DC power supply to ground.

10. The method of claim 8, wherein the DC power supply bipolar ground protection method is characterized by, The second sampling voltage threshold U' s is: wherein R g is the equivalent insulation resistance value of the negative pole of the DC power supply to ground potential.

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