Parallel diode detection circuit

Abstract

The invention discloses a parallel diode detection circuit, which is suitable for detecting a diode circuit connected in parallel with a battery charging and discharging system. A Mid port is electrically connected between a first diode D1 and a second diode D2. The Mid port is also electrically connected to a C contact of a first relay RLY1. An A contact of the first relay RLY1 is electrically connected to an anode of a light-emitting diode in a first photoelectric coupler U1. A B contact is electrically connected to a cathode of a light-emitting diode in a second photoelectric coupler U2. A positive electrode of an auxiliary power supply is electrically connected to a first control end of the first relay RLY1, so that the C contact and the A contact of the first relay RLY1 are in a normally closed state. A switch unit is electrically connected to a Test_control port and a second control end of the first relay RLY1, respectively, so that the C contact and the A contact of the first relay RLY1 are controlled to be disconnected, and the C contact and the B contact are electrically connected. The invention can locally / remotely start the detection of the diode without stopping the equipment. The detection is short in time and high in efficiency, and will not affect the normal operation of the overall system.

Description

Technical Field

[0001] The invention relates to the technical field of quality detection of parallel diodes of battery charging and discharging equipment, and in particular to a parallel diode detection circuit. Background Art

[0002] In the prior art, in order to ensure that the critical loads can maintain long-term uninterrupted working conditions, corresponding auxiliary power supply equipment is configured to deal with short-term power outages of the mains. Commonly used auxiliary power supply equipment is realized in the form of chemical energy storage, hydraulic energy storage, etc. In view of the diversity of auxiliary power supply equipment use sites and the difficulty of installing auxiliary power supply equipment, the industry mainly uses chemical energy storage as auxiliary power supply equipment. Common chemical energy storage types include lead-acid batteries and lithium batteries.

[0003] Lead-acid batteries are the most widely used due to their low price. However, if they are not charged or discharged for a long time, the capacity of the battery will decay significantly. The battery needs to be charged and discharged at regular intervals, which requires charging and discharging equipment to be placed between the battery and the load. Adding charging and discharging equipment will undoubtedly increase system variables in the entire system.

[0004] Therefore, in order to ensure the stability of the system's load power supply, one or a group of diodes must be connected in parallel to the battery charging and discharging equipment. When the battery charging and discharging equipment has problems, the lead-acid battery can directly power the load. However, when the load and the power supply are in a normal connection state, the detection of the diodes connected in parallel to the battery charging and discharging equipment usually requires manual inspection after the system is shut down, which has low work efficiency and high cost. Summary of the invention

[0005] The purpose of the present invention is to provide a parallel diode detection circuit, which can locally / remotely start the detection of the quality of the diode without stopping the equipment. The detection is time-saving and efficient, and the detection process will not affect the normal operation of the overall system.

[0006] In order to achieve the above purpose, the present invention discloses a parallel diode detection circuit, which is suitable for detecting a diode circuit connected in parallel with a battery charging and discharging system. The negative electrode of the backup battery of the battery charging and discharging system is electrically connected to the negative electrode of the load to form a negative electrode main path. The diode circuit is arranged in parallel with the negative electrode main path. The diode circuit includes a first diode D1 and a second diode D2 arranged in series. The parallel diode detection circuit includes a Test_control port, a Normal port, a Test port, a Mid port, a first relay RLY1, a first photoelectric coupler U1, a second photoelectric coupler U2 and a switch unit. The Test_control port, the Normal port and the Test port are electrically connected to a control chip respectively. The Mid port is electrically connected between the first diode D1 and the second diode D2. The Mid port is also electrically connected to the C contact of the first relay RLY1, and the A contact of the first relay RLY1 is electrically connected to the light-emitting diode in the first photoelectric coupler U1. The anode of the light-emitting diode in the first photocoupler U1 is electrically connected to the cathode of the light-emitting diode in the second photocoupler U2, the cathode of the light-emitting diode in the first photocoupler U1 is electrically connected to the negative electrode of an auxiliary power supply, the anode of the light-emitting diode in the second photocoupler U2 is electrically connected to the positive electrode of the backup battery, the emitter of the photosensitive transistor in the first photocoupler U1 is electrically connected to the negative electrode main circuit, and the collector is electrically connected to the Normal port, the emitter of the photosensitive transistor in the second photocoupler U2 is grounded, and the collector is electrically connected to the Test port, the positive electrode of the auxiliary power supply is electrically connected to the first control end of the first relay RLY1, so that the C contact and the A contact of the first relay RLY1 are in a normally closed state, the switch unit is electrically connected to the Test_control port and the second control end of the first relay RLY1 respectively, and the switch unit controls the C contact of the first relay RLY1 to be disconnected from the A contact according to the level change of the Test_control port, and makes the C contact electrically connected to the B contact.

[0007] Compared with the prior art, the present invention controls the level change of the Test_control port to control the electrical connection between the C contact and the A contact of the first relay RLY1 to be converted into the electrical connection between the C contact and the B contact, thereby realizing the switching of the conduction circuit of the first diode D1 and the second diode D2 by remote / locally controlling the level change of the Test_control port without stopping the equipment, so as to test the quality of the first diode D1 and the second diode D2.

[0008] Preferably, by switching the state of the first relay RLY1 to switch the test circuit where the first diode D1 and the second diode D2 are located, the quality of the second diode D2 is judged according to the level state of the Normal port, and the quality of the first diode D1 is judged according to the level state of the Test port.

[0009] Preferably, the switching unit includes a transistor Q1, a base of the transistor Q1 being electrically connected to the Test_control port, an emitter being grounded, and a collector being electrically connected to the second control end of the first relay RLY1. The transistor Q1 controls the C contact and the A contact of the first relay RLY1 to be disconnected and the C contact and the B contact to be electrically connected according to the level change of the Test_control port.

[0010] Preferably, the parallel diode detection circuit also includes a transistor protection circuit, which includes a voltage regulator diode ZD1 and a first resistor R1, wherein the cathode of the voltage regulator diode ZD1 is electrically connected to the Test_control port, and the anode is electrically connected to the base of the transistor Q1 through the first resistor R1.

[0011] Specifically, the parallel diode detection circuit also includes a second resistor R2 and a first capacitor C1. After the second resistor R2 and the first capacitor C1 are connected in parallel, one end is electrically connected between the first resistor R1 and the base of the transistor Q1, and the other end is connected between the emitter of the transistor Q1 and the ground.

[0012] Preferably, the parallel diode detection circuit also includes a peak absorption circuit, which includes two third diodes D3, the cathodes of the two third diodes D3 connected in parallel are electrically connected to the first control end of the first relay RLY1, and the anodes are electrically connected to the second control end of the first relay RLY1.

[0013] Preferably, the parallel diode detection circuit further includes an energy storage circuit, which includes a second capacitor C2, one end of which is electrically connected between the positive electrode of the auxiliary power supply and the first control end of the first relay RLY1, and the other end of which is grounded.

[0014] Preferably, the parallel diode detection circuit also includes a first current limiting circuit, which includes a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The third resistor R3 and the fourth resistor R4 are connected in parallel and in series between the cathode of the light-emitting diode in the first photocoupler U1 and the negative electrode of the auxiliary power supply.

[0015] Preferably, the parallel diode detection circuit also includes a second current limiting circuit, which includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. The sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are connected in parallel and in series between the anode of the light-emitting diode in the second photocoupler U2 and the positive electrode of the backup battery.

[0016] Preferably, the positive electrode of the auxiliary power supply provides a voltage of +12V, and the negative electrode provides a voltage of -12V.

[0017] Preferably, the electrical connection point between the emitter of the phototransistor in the first photocoupler U1 and the negative electrode main circuit is grounded. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a circuit diagram of the parallel diode detection circuit of the present invention connected to a battery charging and discharging system;

[0019] Figure 2 1 is a circuit diagram of a parallel diode detection circuit of the present invention. DETAILED DESCRIPTION

[0020] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0021] See also Figure 1 and Figure 2 As shown, the parallel diode detection circuit of this embodiment is suitable for detecting a diode circuit connected in parallel with a battery charging and discharging system. The negative electrode of the backup battery of the battery charging and discharging system is electrically connected to the negative electrode of the load to form a negative electrode main circuit. Preferably, the backup battery and the load of the battery charging and discharging system are constructed by fuses, relay switching circuits, bus capacitors, power inductors and bypass relays. The circuit structure of the backup battery and the load of the battery charging and discharging system is a common circuit construction method, which will not be described in detail here.

[0022] The diode circuit is arranged in parallel with the negative main circuit, and the diode circuit includes a first diode D1 and a second diode D2 arranged in series. The parallel diode detection circuit includes a Test_control port, a Normal port, a Test port, a Mid port, a first relay RLY1, a first photocoupler U1, a second photocoupler U2 and a switch unit. The Test_control port, the Normal port, and the Test port are respectively electrically connected to a control chip (not shown in the figure). The control chip is preferably a DSP control chip, which can send test instructions to the Test_control port on-site or remotely, and detect the level changes of the Normal port and the Test port in real time. The output of the control chip is connected to a +12V pull-up voltage.

[0023] The Mid port is electrically connected between the first diode D1 and the second diode D2, and is also electrically connected to the C contact of the first relay RLY1. The A contact of the first relay RLY1 is electrically connected to the anode of the light-emitting diode in the first photocoupler U1, and the B contact is electrically connected to the cathode of the light-emitting diode in the second photocoupler U2. The cathode of the light-emitting diode in the first photocoupler U1 is electrically connected to the negative electrode of an auxiliary power supply, and the anode of the light-emitting diode in the second photocoupler U2 is electrically connected to the positive electrode of the backup battery. The emitter of the phototransistor in the first photocoupler U1 is electrically connected to the negative main circuit, and the collector The Normal port is electrically connected, the emitter of the phototransistor in the second photocoupler U2 is grounded, the collector is electrically connected to the Test port, the positive electrode of the auxiliary power supply is electrically connected to the first control end of the first relay RLY1, so that the C contact and the A contact of the first relay RLY1 are in a normally closed state, the switch unit is electrically connected to the Test_control port and the second control end of the first relay RLY1 respectively, and the switch unit controls the C contact and the A contact of the first relay RLY1 to be disconnected and the C contact and the B contact according to the level change of the Test_control port. By switching the state of the first relay RLY1, the test circuit where the first diode D1 and the second diode D2 are located is switched, and the quality of the second diode D2 is judged according to the level state of the Normal port, and the quality of the first diode D1 is judged according to the level state of the Test port.

[0024] Preferably, the switching unit includes a transistor Q1, a base of the transistor Q1 being electrically connected to the Test_control port, an emitter being grounded, and a collector being electrically connected to the second control end of the first relay RLY1. The transistor Q1 controls the C contact and the A contact of the first relay RLY1 to be disconnected and the C contact and the B contact to be electrically connected according to the level change of the Test_control port.

[0025] Preferably, the parallel diode detection circuit also includes a transistor protection circuit, which includes a voltage-stabilizing diode ZD1 and a first resistor R1, the cathode of the voltage-stabilizing diode ZD1 is electrically connected to the Test_control port, and the anode is electrically connected to the base of the transistor Q1 through the first resistor R1, and the voltage-stabilizing diode ZD1 stabilizes the base voltage of the transistor Q1 at 3.3V after being turned on.

[0026] Specifically, the parallel diode detection circuit also includes a second resistor R2 and a first capacitor C1. After the second resistor R2 and the first capacitor C1 are connected in parallel, one end is electrically connected between the first resistor R1 and the base of the transistor Q1, and the other end is connected between the emitter of the transistor Q1 and the ground.

[0027] Preferably, the parallel diode detection circuit also includes a peak absorption circuit, which includes two third diodes D3, the cathodes of the two third diodes D3 connected in parallel are electrically connected to the first control end of the first relay RLY1, and the anodes are electrically connected to the second control end of the first relay RLY1.

[0028] Preferably, the parallel diode detection circuit further includes an energy storage circuit, which includes a second capacitor C2, one end of which is electrically connected between the positive electrode of the auxiliary power supply and the first control end of the first relay RLY1, and the other end of which is grounded.

[0029] Preferably, the parallel diode detection circuit also includes a first current limiting circuit, which includes a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The third resistor R3 and the fourth resistor R4 are connected in parallel and in series between the cathode of the light-emitting diode in the first photocoupler U1 and the negative electrode of the auxiliary power supply.

[0030] Preferably, the parallel diode detection circuit also includes a second current limiting circuit, which includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. The sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are connected in parallel and in series between the anode of the light-emitting diode in the second photocoupler U2 and the positive electrode of the backup battery.

[0031] Preferably, the positive electrode of the auxiliary power supply provides a voltage of +12V, and the negative electrode provides a voltage of -12V.

[0032] Preferably, the electrical connection point between the emitter of the phototransistor in the first photocoupler U1 and the negative electrode main circuit is grounded, so that the ground voltage of the parallel diode detection circuit is equal to the negative electrode voltage of the backup battery.

[0033] The detection process of the parallel diode detection circuit of this embodiment is described in detail below:

[0034] When the battery charging and discharging system is powered on, the level of the Test_control port has two states: low level and high level:

[0035] 1. When the level of the Test_control port is low, the voltage regulator diode ZD1 is not conducting, the transistor Q1 is not conducting, the C contact and the A contact of the first relay RLY1 remain normally closed, and the Mid port is electrically connected to the light-emitting diode in the first photocoupler U1 through the C contact and the A contact of the first relay RLY1, and then connected to the negative electrode (VCC-12V) of the auxiliary power supply through the third resistor R3 and the fourth resistor R4 connected in parallel. At this time, if the second diode D2 is normal, because the potential of the Mid port is equal to GND (-0.7V), the potential of the Mid port is higher than the potential of the negative electrode of the auxiliary power supply (VCC-12V), and the current flows from GND through the second diode D2, the C contact and the A contact of the first relay RLY1, the third resistor R3 and the fourth resistor R4 in parallel, and then flows into the negative electrode of the auxiliary power supply (VCC-12V). At this time, the phototransistor in the first photocoupler U1 is turned on, and the level of the Normal port is clamped to GND, that is, the level of the Normal port is low; if the second diode D2 fails or is damaged, this current loop does not exist, and the phototransistor in the first photocoupler U1 is not turned on, that is, the level of the Normal port is high;

[0036] 2. When the level of the Test_control port is high, the voltage regulator diode ZD1 is turned on, the transistor Q1 is turned on, the C contact and the A contact of the first relay RLY1 are disconnected and the C contact and the B contact are closed, the Mid port is electrically connected to the light-emitting diode in the second photocoupler U2 through the C contact and the B contact of the first relay RLY1, the first diode D1 is connected to the negative electrode BAT- of the backup battery, and the positive electrode BAT+ of the backup battery is electrically connected to the light-emitting diode in the second photocoupler U2 through the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 connected in parallel. Because the potential of the positive electrode BAT+ of the backup battery is higher than that of the negative electrode BAT- of the backup battery, the current passes through the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 connected in parallel, and then flows through the light-emitting diode in the second photocoupler U2, and then passes through the first diode D1 to the negative electrode BAT- of the backup battery. The light-emitting diode in the second photocoupler U2 is turned on. At this time, the Test port is clamped to GND. If the control chip detects that the Test port is at a low level at this time, the first diode D1 is intact; if the control chip detects that the Test port is at a high level at this time, there is a problem with the first diode D1, and further inspection and replacement are required.

[0037] Combination Figure 1 and Figure 2 The present invention controls the level change of the Test_control port to control the electrical connection between the C contact and the A contact of the first relay RLY1 to be converted into the electrical connection between the C contact and the B contact, thereby realizing the switching of the conduction circuit of the first diode D1 and the second diode D2 by remotely / locally controlling the level change of the Test_control port without stopping the equipment, so as to test the quality of the first diode D1 and the second diode D2.

[0038] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A parallel diode detection circuit, suitable for detecting a diode circuit connected in parallel with a battery charging and discharging system, wherein the negative electrode of a backup battery of the battery charging and discharging system is electrically connected to the negative electrode of a load to form a negative electrode main path, and the diode circuit is arranged in parallel with the negative electrode main path, and the diode circuit comprises a first diode D1 and a second diode D2 arranged in series, characterized in that: The parallel diode detection circuit includes a Test_control port, a Normal port, a Test port, a Mid port, a first relay RLY1, a first photocoupler U1, a second photocoupler U2 and a switch unit, wherein the Test_control port, the Normal port and the Test port are electrically connected to a control chip respectively, the Mid port is electrically connected between the first diode D1 and the second diode D2, the Mid port is also electrically connected to the C contact of the first relay RLY1, the A contact of the first relay RLY1 is electrically connected to the anode of the light-emitting diode in the first photocoupler U1, the B contact is electrically connected to the cathode of the light-emitting diode in the second photocoupler U2, the cathode of the light-emitting diode in the first photocoupler U1 is electrically connected to the negative electrode of an auxiliary power supply, and the The anode of the light-emitting diode in the second photocoupler U2 is electrically connected to the positive electrode of the backup battery, the emitter of the phototransistor in the first photocoupler U1 is electrically connected to the negative main circuit, and the collector is electrically connected to the Normal port, the emitter of the phototransistor in the second photocoupler U2 is grounded, and the collector is electrically connected to the Test port, the positive electrode of the auxiliary power supply is electrically connected to the first control end of the first relay RLY1, so that the C contact and the A contact of the first relay RLY1 are in a normally closed state, the switch unit is electrically connected to the Test_control port and the second control end of the first relay RLY1, respectively, and the switch unit controls the C contact of the first relay RLY1 to be disconnected from the A contact according to the level change of the Test_control port, and electrically connects the C contact to the B contact.

2. The parallel diode detection circuit as claimed in claim 1, characterized in that: The switch unit includes a transistor Q1, a base of which is electrically connected to the Test_control port, an emitter is grounded, and a collector is electrically connected to the second control end of the first relay RLY1. The transistor Q1 controls the C contact and the A contact of the first relay RLY1 to be disconnected and the C contact and the B contact to be electrically connected according to the level change of the Test_control port.

3. The parallel diode detection circuit as claimed in claim 2, characterized in that: The parallel diode detection circuit also includes a transistor protection circuit, which includes a voltage stabilizing diode ZD1 and a first resistor R1. The cathode of the voltage stabilizing diode ZD1 is electrically connected to the Test_control port, and the anode is electrically connected to the base of the transistor Q1 through the first resistor R1.

4. The parallel diode detection circuit as claimed in claim 3, characterized in that: The parallel diode detection circuit also includes a second resistor R2 and a first capacitor C1. After the second resistor R2 and the first capacitor C1 are connected in parallel, one end is electrically connected between the first resistor R1 and the base of the transistor Q1, and the other end is connected between the emitter of the transistor Q1 and the ground.

5. The parallel diode detection circuit as claimed in claim 1, characterized in that: The parallel diode detection circuit also includes a peak absorption circuit, which includes two third diodes D3, the cathodes of the two third diodes D3 connected in parallel are electrically connected to the first control end of the first relay RLY1, and the anodes are electrically connected to the second control end of the first relay RLY1.

6. The parallel diode detection circuit as claimed in claim 1, characterized in that: The parallel diode detection circuit also includes an energy storage circuit, which includes a second capacitor C2, one end of which is electrically connected between the positive electrode of the auxiliary power supply and the first control end of the first relay RLY1, and the other end of which is grounded.

7. The parallel diode detection circuit as claimed in claim 1, characterized in that: The parallel diode detection circuit also includes a first current limiting circuit, which includes a third resistor R3, a fourth resistor R4 and a fifth resistor R5. The third resistor R3 and the fourth resistor R4 are connected in parallel and connected in series between the cathode of the light-emitting diode in the first photocoupler U1 and the negative electrode of the auxiliary power supply; the fifth resistor R5 is connected in series between the collector of the photosensitive transistor in the first photocoupler U1 and the Normal port.

8. The parallel diode detection circuit as claimed in claim 1, characterized in that: The parallel diode detection circuit also includes a second current limiting circuit, which includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9. The sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are connected in parallel and connected in series between the anode of the light-emitting diode in the second photocoupler U2 and the positive electrode of the backup battery; the ninth resistor R9 is connected in series between the collector of the phototransistor in the second photocoupler U2 and the Test port.

9. The parallel diode detection circuit as claimed in claim 1, characterized in that: The positive electrode of the auxiliary power supply provides a voltage of +12V, and the negative electrode provides a voltage of -12V.

10. The parallel diode detection circuit as claimed in claim 1, characterized in that: The electrical connection point between the emitter of the phototransistor in the first photocoupler U1 and the negative electrode main circuit is grounded.

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