Ship system insulation resistance detection circuit

Abstract

The application relates to a ship system insulation resistance detection circuit, which comprises a main control board, a first collection module, a first detection circuit, a second detection circuit, a second collection module, the input end of the first detection circuit is adapted to be electrically connected with the output end of a positive high-voltage line, the output end of the first detection circuit is grounded, the input end of the second detection circuit is adapted to be electrically connected with the output end of a negative high-voltage line, and the output end of the second detection circuit is grounded; the first detection circuit comprises a first equivalent resistor, a first relay and a first voltage division resistor which are connected in series; the collection end of the first collection module is connected with the input end and the output end of the first voltage division resistor respectively; the second detection circuit comprises a second equivalent resistor, a second relay and a second voltage division resistor which are connected in series; the collection end of the second collection module is connected with the input end and the output end of the second voltage division resistor respectively; and the output ends of the first collection module and the second collection module are connected with the input end of the main control board.

Description

Technical Field

[0001] This application relates to the field of ship system computing, and in particular to a ship system insulation resistance detection circuit. Background Technology

[0002] Shipboard electrical systems are a collective term for all equipment and devices that ensure the normal navigation, operation, and crew life of a vessel. They primarily encompass core components such as power distribution systems, propulsion control systems, and auxiliary power supply devices. Shipboard electrical equipment is constantly exposed to the humid, salty marine environment. This harsh environment causes the insulation layers of electrical equipment to age and deteriorate, ultimately leading to a decrease in insulation resistance and posing a risk of leakage and short circuits. Currently, the insulation resistance testing of shipboard systems commonly uses a hand-cranked megohmmeter as the core tool. However, this testing method requires first disconnecting the main power supply to the electrical circuit being tested. Only after the circuit is completely de-energized can the megohmmeter be connected for measurement. This power-off operation directly forces the interruption of the corresponding work process, resulting in the ship being unable to operate normally during the testing period, seriously affecting navigation safety and operational efficiency. Summary of the Invention

[0003] In view of this, this application proposes a ship system insulation resistance detection circuit for parallel connection with the positive high voltage line and negative high voltage line of the ship's DC system, comprising: a main control board, a first acquisition module, a first detection circuit, a second detection circuit, and a second acquisition module; The input terminal of the first detection circuit is suitable for connecting the output terminal of the positive high voltage line, and the output terminal of the first detection circuit is grounded. The input terminal of the second detection circuit is suitable for connecting the output terminal of the negative high voltage line, and the output terminal of the second detection circuit is grounded. The first detection circuit includes: a first equivalent resistor, a first relay, and a first voltage divider resistor connected in series; the acquisition terminal of the first acquisition module is connected to the input terminal and the output terminal of the first voltage divider resistor, respectively. The second detection circuit includes: a second equivalent resistor, a second relay, and a second voltage divider resistor connected in series; the acquisition terminal of the second acquisition module is connected to the input terminal and the output terminal of the second voltage divider resistor, respectively. The output terminals of the first and second acquisition modules are both connected to the input terminals of the main control board. The output terminals of the main control board are connected to the control terminals of the first and second relays, respectively. The main control board is suitable for time-sharing control of their on / off states. Specifically, the main control board controls the second relay to open while closing the first relay, so that the first acquisition module can acquire the first voltage value on the first voltage divider resistor; after receiving the first voltage value, the main control board disconnects the first relay and closes the second relay, so that the second acquisition module can acquire the second voltage value on the second voltage divider resistor; the main control board calculates the insulation resistance of the positive high voltage line grounding and the insulation resistance of the negative high voltage line grounding based on the first voltage value and the second voltage value.

[0004] In one possible implementation, the first acquisition module includes: an isolation amplifier and an operational amplifier; The first acquisition terminal of the isolation amplifier is connected to the input terminal of the first voltage divider resistor, and the second acquisition terminal of the isolation amplifier is connected to the output terminal of the first voltage divider resistor; The first output terminal of the isolation amplifier is connected to the first input terminal of the operational amplifier, the second output terminal of the isolation amplifier is connected to the second input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the input terminal of the main control board.

[0005] In one possible implementation, a first isolated power supply module is also included; the input of the first isolated power supply module is adapted to be electrically connected to the output of the ship's DC system, and the output of the first isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the first acquisition module, respectively.

[0006] In one possible implementation, it further includes: a second isolated power supply module; the input of the second isolated power supply module is adapted to be electrically connected to the output of the ship's DC system, and the output of the second isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the second acquisition module, respectively.

[0007] In one possible implementation, a first control circuit is also included; the output of the first control circuit is electrically connected to the control terminal of the first relay, and the input of the first control circuit is electrically connected to the output of the main control board, the main control board being adapted to output control signals to the first relay through the first control circuit.

[0008] In one possible implementation, the first control circuit further includes a first NMOS transistor; the gate (G) of the first NMOS transistor is electrically connected to the output terminal of the main control board, and the drain (D) of the first NMOS transistor is electrically connected to the control terminal of the first relay.

[0009] In one possible implementation, a second control circuit is also included; the output of the second control circuit is electrically connected to the control terminal of the second relay, and the input of the second control circuit is electrically connected to the main control board.

[0010] In one possible implementation, the second control circuit further includes a second NMOS transistor; the gate (G) of the second NMOS transistor is electrically connected to the output terminal of the main control board, and the drain (D) of the second NMOS transistor is electrically connected to the control terminal of the second relay.

[0011] In one possible implementation, a filter capacitor is also included; one end of the filter capacitor is connected to the first input terminal of the operational amplifier, and the other end of the filter capacitor is connected to the output terminal of the operational amplifier.

[0012] Beneficial effects of this application When the insulation resistance of the positive high-voltage line needs to be tested, the main control board controls the first relay U39 to close while keeping the second relay U44 open. At this time, the current of the positive high-voltage line of the ship's DC system forms a circuit through the first equivalent resistor, the first relay U39, and the first voltage divider resistor R256. The first acquisition module acquires the first voltage value of the first voltage divider resistor R256 and transmits it to the main control board. When the insulation resistance of the negative high-voltage line needs to be tested, the main control board controls the second relay U44 to close while opening the first relay U39. At this time, the current of the negative high-voltage line of the ship's DC system forms a circuit through the second equivalent resistor, the second relay U44, and the second voltage divider resistor R265. The second acquisition module acquires the second voltage value of the second voltage divider resistor R265 and transmits it to the main control board.

[0013] Based on the acquired first and second voltage values, and combined with the known parameters of the first equivalent resistance, the first voltage divider resistor R256, the second equivalent resistance, and the second voltage divider resistor R265, the main control board can calculate the grounding insulation resistance of the positive high-voltage line (i.e., the insulation resistance of the +750V busbar to the ground) and the grounding insulation resistance of the negative high-voltage line (i.e., the insulation resistance of the -750V busbar to the ground) by combining Ohm's law and the law of conservation of current.

[0014] The main control board determines whether the insulation performance of the positive high-voltage line (i.e., +750V single-line voltage) to ground and the negative high-voltage line (i.e., -750V single-line voltage) to ground meets the safety requirements based on the calculated insulation resistance Rx and insulation resistance Ry. When both insulation resistance Rx and insulation resistance Ry are greater than the preset safety threshold, the insulation state of the ship's electrical system is stable and there is no risk of leakage, which is considered a normal and safe state. When either insulation resistance Rx or Ry is less than the preset safety threshold, it indicates that there is a risk of leakage in the insulation layer of the corresponding single line. In this case, manual inspection and maintenance should be arranged to replace aging insulation components to avoid safety accidents.

[0015] The ship system insulation resistance detection circuit of this application, through its design of being connected in parallel with the positive and negative high-voltage lines of the ship's DC system, allows for testing without disconnecting the main power supply. Compared with existing offline megohmmeter testing, this insulation resistance detection circuit eliminates the need for manual power disconnection and wire disconnection, reducing labor costs, avoiding operational interruptions due to power outages, and ensuring that testing can be performed even during normal navigation or operation, thus guaranteeing navigation safety and operational efficiency. During operation, the main control board controls the switching on and off of the first relay U39 and the second relay U44 in a time-division manner, thereby enabling separate detection of the insulation resistance to ground of the positive and negative high-voltage lines. The crew or ship monitoring system can use the insulation resistance value calculated by the main control board to effectively prevent leakage, short circuits, and electric shock accidents, improving the safety and reliability of the ship's electrical system.

[0016] Other features and aspects of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this application together with the specification and serve to explain the principles of this application.

[0018] Figure 1 A circuit diagram showing a ship system insulation resistance detection circuit according to an embodiment of this application is provided. Figure 2 Show Figure 1 A simplified circuit diagram; Figure 3 This paper shows a circuit diagram of a first isolated power supply module according to an embodiment of this application; Figure 4 The circuit diagram of the second isolated power supply module according to an embodiment of this application is shown. Detailed Implementation

[0019] Various exemplary embodiments, features, and aspects of this application will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0020] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0023] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented without certain specific details. In some instances, methods, means, components, and circuits well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.

[0024] This application proposes a ship system insulation resistance detection circuit, suitable for parallel connection with the positive and negative high-voltage lines of a ship's DC system, comprising: a main control board, a first acquisition module, a first detection circuit, a second detection circuit, and a second acquisition module; the input terminal of the first detection circuit is electrically connected to the output terminal of the positive high-voltage line, and the output terminal of the first detection circuit is grounded; the input terminal of the second detection circuit is electrically connected to the output terminal of the negative high-voltage line, and the output terminal of the second detection circuit is grounded; the first detection circuit includes: a first equivalent resistor, a first relay U39, and a first voltage divider resistor R256 connected in series; the acquisition terminal of the first acquisition module is connected to the input terminal and the output terminal of the first voltage divider resistor R256, respectively; the second detection circuit includes: a second equivalent resistor, a second relay U44, and a second voltage divider resistor R265 connected in series; the second acquisition module... The acquisition terminals are connected to the input and output terminals of the second voltage divider resistor R265, respectively. The output terminals of the first acquisition module and the second acquisition module are both connected to the input terminals of the main control board. The output terminals of the main control board are connected to the control terminals of the first relay U39 and the second relay U44, respectively. The main control board is suitable for time-division control of their on / off states. When the main control board controls the on / off state of the relays, it controls the second relay U44 to open while closing the first relay U39, so that the first acquisition module acquires the first voltage value of the first voltage divider resistor R256. After receiving the first voltage value, the main control board disconnects the first relay U39 and closes the second relay U44, so that the second acquisition module acquires the second voltage value of the second voltage divider resistor R265. The main control board calculates the insulation resistance of the positive high-voltage line grounding and the insulation resistance of the negative high-voltage line grounding based on the first voltage value and the second voltage value.

[0025] It should be noted that the first detection circuit is connected in parallel with the positive high-voltage line (i.e., +750V single-line voltage) of the ship system. Without disconnecting the power supply to the positive high-voltage line, it directionally detects the insulation state of the positive high-voltage line (i.e., +750V single-line voltage) to the ground, thus providing a basis for calculating the grounding insulation resistance of the positive high-voltage line. The second detection circuit is connected in parallel with the negative high-voltage line (i.e., -750V single-line voltage) of the ship system. Without disconnecting the power supply to the negative high-voltage line, it directionally detects the insulation state of the negative high-voltage line (i.e., -750V single-line voltage) to the ground, thus providing a basis for calculating the grounding insulation resistance of the negative high-voltage line. The first and second detection circuits can independently detect the insulation resistance of the positive and negative high-voltage lines (i.e., ±750V single-line voltage) to ground.

[0026] The input terminal of the first equivalent resistor is connected to the output terminal of the positive high voltage line (i.e., +750V single-line voltage). The output terminal of the first equivalent resistor is connected to the LOAD_AC_A pin of the first relay U39. The LOAD_AC_B pin of the first relay U39 is connected to the input terminal of the first voltage divider resistor R256. The output terminal of the first voltage divider resistor R256 is grounded. The first acquisition module is used to acquire the voltage (i.e., the first voltage value) across the first voltage divider resistor R256. The output terminal of the first acquisition module is connected to the input terminal of the main control board. The first acquisition module transmits the acquired first voltage value to the main control board, thereby providing a basis for calculating the grounding insulation resistance of the positive high voltage line. The input terminal of the second equivalent resistor is connected to the output terminal of the negative high-voltage line (i.e., -750V single-line voltage). The output terminal of the second equivalent resistor is connected to the LOAD_AC_A pin of the second relay U44. The LOAD_AC_B pin of the second relay U44 is connected to the input terminal of the second voltage divider resistor R265. The output terminal of the second voltage divider resistor R265 is grounded. The second acquisition module is used to acquire the voltage (second voltage value) across the second voltage divider resistor R265. The output terminal of the second acquisition module is connected to the input terminal of the main control board. The second acquisition module transmits the acquired second voltage value to the main control board, thereby providing a basis for calculating the grounding insulation resistance of the negative high-voltage line.

[0027] The main control board is connected to the LED pins of the first relay U39 and the second relay U44 respectively. The main control board controls the on / off state of the first relay U39 and the second relay U44 by outputting control signals, and receives and processes the voltage data from the first acquisition module and the second acquisition module to calculate the insulation resistance of the positive high voltage line grounding and the insulation resistance of the negative high voltage line grounding. The time-division control design avoids the signal superposition of the two detection circuits working at the same time, which would cause cross-interference of the positive and negative high voltage line detection signals.

[0028] When the ship's system starts up, both the first relay U39 and the second relay U44 are in the open state, and there is no current in the first and second detection circuits. The ship's DC system normally supplies power to the electrical equipment. When it is necessary to detect the insulation resistance of the positive high-voltage line, the main control board controls the first relay U39 to close while keeping the second relay U44 open. At this time, the current of the positive high-voltage line of the ship's DC system forms a loop through the first equivalent resistor, the first relay U39, and the first voltage divider resistor R256. The first acquisition module acquires the first voltage value of the first voltage divider resistor R256 and transmits it to the main control board. When it is necessary to detect the insulation resistance of the negative high-voltage line, the main control board controls the second relay U44 to close while opening the first relay U39. At this time, the current of the negative high-voltage line of the ship's DC system forms a loop through the second equivalent resistor, the second relay U44, and the second voltage divider resistor R265. The second acquisition module acquires the second voltage value of the second voltage divider resistor R265 and transmits it to the main control board.

[0029] Based on the acquired first and second voltage values, and combined with the known parameters of the first equivalent resistance, the first voltage divider resistor R256, the second equivalent resistance, and the second voltage divider resistor R265, the main control board calculates the grounding insulation resistance of the positive high-voltage line (i.e., the insulation resistance of the +750V busbar to the ground) and the grounding insulation resistance of the negative high-voltage line (i.e., the insulation resistance of the -750V busbar to the ground) by applying Ohm's law and the law of conservation of current. The specific derivation is as follows: When the main control board controls the first relay U39 to close while keeping the second relay U44 open, the following derivation is based on the first voltage value: S110: I1=U1 / R1, where I1 is the current flowing through the first voltage divider resistor R256, U1 is the voltage across the first voltage divider resistor R256, and R1 is the resistance of the first voltage divider resistor R256, which is a known fixed resistance. The current I1 flowing through the first voltage divider resistor R256 can be obtained using Ohm's law.

[0030] S120: Among them, the voltage of the insulation resistance of the positive high voltage line (i.e., +750V single line voltage) is Ux, the insulation resistance of the positive high voltage line (i.e., +750V single line voltage) is Rx, and the current flowing through the insulation resistance of the positive high voltage line (i.e., +750V single line voltage) is Ix.

[0031] S130: Since the first detection circuit is connected in parallel with the insulation resistance of the positive high voltage line (i.e., +750V single-line voltage), according to the basic principle of parallel circuits, the voltages of the two circuits are the same in the parallel circuit. Therefore, the voltage of the insulation resistance of the positive high voltage line (i.e., +750V single-line voltage) can be derived as Ux: Ux=I1×(Ra+R1), where Ra is the sum of the first equivalent resistance and the internal resistance of the first relay U39, and Ra is a known fixed resistance value.

[0032] S140: I1+Ix is the inflow current, and the outflow current is: According to the law of conservation of current, the inflow current equals the outflowing current, therefore: .

[0033] S150: By rearranging the above formulas, we can obtain the correlation equation 1: When the main control board controls the second relay U44 to close while keeping the first relay U39 open, the following derivation is based on the second voltage value: S210: I2=U2 / R2, where I2 is the current flowing through the second voltage divider resistor R265, U2 is the voltage across the second voltage divider resistor R265, and R2 is the resistance of the second voltage divider resistor R265, which is a known fixed resistance. The current I2 flowing through the second voltage divider resistor R265 can be obtained using Ohm's law.

[0034] S220: Among them, the voltage of the insulation resistance of the negative high voltage line (i.e., -750V single line voltage) is Uy, the insulation resistance of the negative high voltage line (i.e., -750V single line voltage) is Ry, and the current flowing through the insulation resistance of the negative high voltage line (i.e., -750V single line voltage) is Iy.

[0035] S230: Since the second detection circuit is connected in parallel with the insulation resistance of the negative high-voltage line (i.e., -750V single-line voltage), according to the basic principle of parallel circuits, the voltages of the two circuits are the same in the parallel circuit. Therefore, the voltage of the insulation resistance of the negative high-voltage line (i.e., -750V single-line voltage) can be derived as Uy: Uy=I2×(Rb+R2), where Rb is the sum of the second equivalent resistance and the internal resistance of the second relay U44, and Rb is a known fixed resistance value.

[0036] S240: I2+Iy is the inflow current, and the outflow current is: According to the law of conservation of current, the inflow current equals the outflowing current, therefore: .

[0037] S260: By rearranging the above formulas, we can obtain equation 2: Solving equations 1 and 2 simultaneously yields the insulation resistances Rx and Ry.

[0038] The main control board determines whether the insulation performance of the positive high-voltage line (i.e., +750V single-line voltage) and the negative high-voltage line (i.e., -750V single-line voltage) meets safety requirements based on the calculated insulation resistances Rx and Ry. When both insulation resistances Rx and Ry are greater than the preset safety threshold, the insulation state of the ship's electrical system is stable and there is no risk of leakage, thus it is considered a normal and safe state. When either insulation resistance Rx or Ry is less than the preset safety threshold, it indicates that there is a risk of leakage in the insulation layer of the corresponding single line. In this case, manual inspection and repair should be arranged, and aging insulation components should be replaced to avoid safety accidents. The preset safety threshold is 1MΩ.

[0039] The ship system insulation resistance detection circuit of this application, through its design of being connected in parallel with the positive and negative high-voltage lines of the ship's DC system, allows for testing without disconnecting the main power supply. Compared with existing offline megohmmeter testing, this insulation resistance detection circuit eliminates the need for manual power disconnection and wire disconnection, reducing labor costs, avoiding operational interruptions due to power outages, and ensuring that testing can be performed even during normal navigation or operation, thus guaranteeing navigation safety and operational efficiency. During operation, the main control board controls the switching on and off of the first relay U39 and the second relay U44 in a time-division manner, thereby enabling separate detection of the insulation resistance to ground of the positive and negative high-voltage lines. The crew or ship monitoring system can use the insulation resistance value calculated by the main control board to effectively prevent leakage, short circuits, and electric shock accidents, improving the safety and reliability of the ship's electrical system.

[0040] In one possible implementation, the first equivalent resistance includes resistors R248, R249, and R251 connected in series; the second equivalent resistance includes resistors R268, R269, and R271, wherein the sum of the resistance values ​​of resistors R248, R249, and R251 is equal to the sum of the resistance values ​​of resistors R268, R269, and R271.

[0041] In one possible implementation, the first acquisition module includes: an isolation amplifier and an operational amplifier; the first acquisition terminal of the isolation amplifier U40 is connected to the input terminal of the first voltage divider resistor R256, and the second acquisition terminal of the isolation amplifier U40 is connected to the output terminal of the first voltage divider resistor R256; the first output terminal of the isolation amplifier U40 is connected to the first input terminal of the operational amplifier U41A, the second output terminal of the isolation amplifier U40 is connected to the second input terminal of the operational amplifier U41A, and the output terminal of the operational amplifier U41A is connected to the input terminal of the main control board.

[0042] It should be noted that the VIN+ pin of isolation amplifier U40 is electrically connected to the input terminal of the first voltage divider resistor R256, and the VIN- pin of isolation amplifier U40 is electrically connected to the output terminal of the first voltage divider resistor R256. The two ends of resistor R254 are connected to the VIN+ pin of isolation amplifier U40 and the input terminal of the first voltage divider resistor R256, respectively. The VOUT- pin of isolation amplifier U40 is electrically connected to the negative input terminal of operational amplifier U41A, and the VOUT+ pin of isolation amplifier U40 is electrically connected to the positive input terminal of operational amplifier U41A. The output terminal of operational amplifier U41A is connected to the input terminal of the main control board.

[0043] Furthermore, it also includes capacitor C178, one end of which is electrically connected to GND1 of isolation amplifier U40, and the other end of which is electrically connected between resistor R254 and VIN+ pin of isolation amplifier U40.

[0044] In one possible implementation, the second acquisition module includes an isolation amplifier U42 and an operational amplifier U41B. The VIN+ pin of the isolation amplifier U42 is electrically connected to the input terminal of the second voltage divider resistor R265, and the VIN- pin of the isolation amplifier U42 is electrically connected to the output terminal of the second voltage divider resistor R265. The two ends of the resistor R263 are respectively connected to the VIN+ pin of the isolation amplifier U42 and the input terminal of the second voltage divider resistor R265. The VOUT- pin of the isolation amplifier U42 is electrically connected to the negative input terminal of the operational amplifier U41B, and the VOUT+ pin of the isolation amplifier U42 is electrically connected to the positive input terminal of the operational amplifier U41B. The output terminal of the operational amplifier U41B is connected to the input terminal of the main control board.

[0045] Furthermore, it also includes capacitor C181, one end of which is electrically connected to GND1 of isolation amplifier U42, and the other end of which is electrically connected between resistor R263 and VIN+ pin of isolation amplifier U42.

[0046] In one possible implementation, a first isolated power supply module is also included; the input of the first isolated power supply module is adapted to be electrically connected to the output of the ship's DC system, and the output of the first isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the first acquisition module, respectively.

[0047] It should be noted that the first isolated power supply module is used to construct an isolated power network ISO_VCC_5V_750V+_Detection and GND_EARTH_750V+ for the first detection circuit; the +VOUT pin of the first isolated power supply module U38 is connected to ISO_VCC_5V_750V+_Detection, and ISO_VCC_5V_750V+_Detection is connected to the VDD1 pin of the isolated amplifier U40, thereby providing a 5V operating power supply for the isolated amplifier U40; the -VOUT pin of the first isolated power supply module U38 is connected to GND_EARTH. The power supply is connected to DSP_AVCC_5V, and GND_EARTH_750V+ is electrically connected to the GND1 pin of the isolation amplifier U40 to form an isolation-side power supply loop; the +VIN pin of the first isolation power supply module is electrically connected to DSP_AVCC_5V, and the -VIN pin of the first isolation module is electrically connected to DSP_AGND; the VDD2 pin of the isolation amplifier U40 is connected to DSP_AVCC_5V, the GND2 pin of the isolation amplifier U40 is connected to DSP_AGND, the positive power supply pin 4 of the operational amplifier U41A is connected to DSP_AVCC_5V, and the negative power supply pin 11 of the operational amplifier U41A is connected to DSP_AGND.

[0048] Furthermore, it also includes capacitors C174 and C173; one end of capacitor C174 is connected to the +VOUT pin of the first isolated power supply module U38, and the other end of capacitor C174 is connected to the -VOUT pin of the first isolated power supply module U38; one end of capacitor C173 is connected to the -VIN pin of the first isolated power supply module, and the other end of capacitor C173 is connected to the +VIN pin of the first isolated power supply module.

[0049] In one possible implementation, a second isolated power supply module is also included; the input of the second isolated power supply module is adapted to be electrically connected to the output of the ship's DC system, and the output of the second isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the second acquisition module, respectively.

[0050] It should be noted here that the second isolated power supply module is used to construct an isolated power network ISO_VCC_5V_750V-_Detection and GND_EARTH_750V- for the second detection circuit; the +VOUT pin of the second isolated power supply module U39 is connected to ISO_VCC_5V_750V-_Detection, and ISO_VCC_5V_750V-_Detection is connected to the VDD1 pin of the isolated amplifier U42, thereby providing a 5V operating power supply for the isolated amplifier U42; the -VOUT pin of the first isolated power supply module U39 is connected to GND_EARTH. The GND_EARTH_750V- pin is electrically connected to the GND1 pin of the isolation amplifier U42 to form an isolation-side power supply loop; the +VIN pin of the second isolation power supply module U3 is electrically connected to DSP_AVCC_5V, and the -VIN pin of the second isolation module is electrically connected to DSP_AGND; the VDD2 pin of the isolation amplifier U42 is connected to DSP_AVCC_5V, the GND2 pin of the isolation amplifier U42 is connected to DSP_AGND, the positive power supply pin 4 of the operational amplifier U41B is connected to DSP_AVCC_5V, and the negative power supply pin 11 of the operational amplifier U41B is connected to DSP_AGND.

[0051] Furthermore, it also includes: capacitor C185 and capacitor C184. One end of capacitor C185 is connected to the +VOUT pin of the second isolated power supply module U39, and the other end of capacitor C185 is connected to the -VOUT pin of the second isolated power supply module U39; one end of capacitor C184 is connected to the -VIN pin of the second isolated power supply module U39, and the other end of capacitor C184 is connected to the +VIN pin of the second isolated power supply module U39.

[0052] In one possible implementation, a first control circuit is also included; the output of the first control circuit is electrically connected to the control terminal of the first relay U39, and the input of the first control circuit is electrically connected to the output of the main control board. The main control board is adapted to output control signals to the first relay U39 through the first control circuit.

[0053] It should be noted that the output terminal of the first control circuit is connected to the LED-pin of the first relay U39, and the input terminal of the first control circuit is electrically connected to the output terminal of the main control board. The main control board sends corresponding control signals to the input terminal of the first control circuit, and the first control circuit receives the control signals from the main control board and transmits them to the first relay U39, thereby controlling the on / off state of the first relay U39 and realizing precise control of the high-voltage line insulation resistance detection process.

[0054] In one possible implementation, the first control circuit further includes a first NMOS transistor; the gate (G) of the first NMOS transistor is electrically connected to the output terminal of the main control board, the drain (D) of the first NMOS transistor is electrically connected to the control terminal of the first relay U39; and the source (S) of the first NMOS transistor Q1 is grounded.

[0055] Furthermore, the first control circuit also includes a resistor R260 and a capacitor C456. The resistor R260 and the capacitor C456 are connected in parallel, and one end of both the resistor R260 and the capacitor C456 are electrically connected to the output terminal of the main control board, while the other end is grounded.

[0056] In one possible implementation, a second control circuit is also included; the output of the second control circuit is electrically connected to the control terminal of the second relay U44, and the input of the second control circuit is electrically connected to the main control board.

[0057] It should be noted that the output of the second control circuit is connected to the LED pin of the second relay U44, and the input of the second control circuit is electrically connected to the output of the main control board. The main control board sends corresponding control signals to the input of the second control circuit, and the second control circuit receives the control signals from the main control board and transmits them to the second relay U44, thereby controlling the on / off state of the second relay U44 and realizing precise control of the insulation resistance detection process of the negative high voltage line.

[0058] In one possible implementation, the second control circuit further includes a second NMOS transistor; the gate of the second NMOS transistor is electrically connected to the output terminal of the main control board, the drain of the second NMOS transistor is electrically connected to the control terminal of the second relay U44, and the source of the second NMOS transistor Q1 is grounded.

[0059] Furthermore, the second control circuit also includes a resistor R272 and a capacitor C457. The resistor R272 and the capacitor C457 are connected in parallel, and one end of the resistor R272 and the capacitor C457 are electrically connected to the output terminal of the main control board, while the other end is grounded.

[0060] In one possible implementation, resistors R255 and R257 are also included. One end of resistor R255 is connected to the first output terminal of the isolation amplifier, and the other end of resistor R255 is connected to the first input terminal of the operational amplifier. One end of resistor R257 is connected to the second output terminal of the isolation amplifier, and the other end of resistor R257 is connected to the second input terminal of the operational amplifier.

[0061] It should be noted that in the first acquisition module, one end of resistor R255 is connected to the VOUT- pin of isolation amplifier U40, and the other end of resistor R255 is electrically connected to the negative input terminal (pin 2) of operational amplifier U41A. One end of resistor R257 is connected to the VOUT+ pin of isolation amplifier U40, and the other end of resistor R257 is electrically connected to the positive input terminal (pin 3) of operational amplifier U41A.

[0062] Furthermore, it also includes resistors 264 and 266; in the second acquisition module, one end of resistor 264 is connected to the VOUT- pin of isolation amplifier U42, and the other end of resistor 264 is electrically connected to the negative input terminal (pin 6) of operational amplifier U41B; one end of resistor 266 is connected to the VOUT+ pin of isolation amplifier U42, and the other end of resistor 266 is electrically connected to the positive input terminal (pin 5) of operational amplifier U41B.

[0063] Furthermore, resistors R255, R257, 264, and 266 are 10K resistors.

[0064] In one possible implementation, capacitor C179 is also included, with one end of capacitor C179 electrically connected to the positive input terminal (pin 3) of operational amplifier U41A and the other end grounded.

[0065] Furthermore, it also includes capacitor C182, one end of which is electrically connected to the positive input terminal (pin 5) of operational amplifier U41B, and the other end is grounded.

[0066] In one possible implementation, a filter capacitor C177 is also included; one end of the filter capacitor C177 is connected to the first input terminal (pin 2) of the operational amplifier, and the other end of the filter capacitor C177 is connected to the output terminal of the operational amplifier.

[0067] Furthermore, it also includes resistor R252, which is connected in parallel with filter capacitor C177.

[0068] Furthermore, it also includes a filter capacitor C180, one end of which is connected to the first input terminal (pin 6) of the operational amplifier U41B, and the other end of which is connected to the output terminal of the operational amplifier U41B.

[0069] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A ship system insulation resistance detection circuit, used in parallel with the positive and negative high-voltage lines of the ship's DC system, characterized in that, include: Main control board, first acquisition module, first detection circuit, second detection circuit, second acquisition module; The input terminal of the first detection circuit is adapted to be electrically connected to the output terminal of the positive high voltage line, and the output terminal of the first detection circuit is grounded. The input terminal of the second detection circuit is adapted to be electrically connected to the output terminal of the negative high voltage line, and the output terminal of the second detection circuit is grounded. The first detection circuit includes: a first equivalent resistor, a first relay, and a first voltage divider resistor connected in series; the acquisition terminal of the first acquisition module is connected to the input terminal and the output terminal of the first voltage divider resistor, respectively. The second detection circuit includes: a second equivalent resistor, a second relay, and a second voltage divider resistor connected in series; the acquisition terminal of the second acquisition module is connected to the input terminal and the output terminal of the second voltage divider resistor, respectively. The output terminals of the first acquisition module and the second acquisition module are both connected to the input terminal of the main control board. The output terminal of the main control board is connected to the control terminal of the first relay and the second relay respectively. The main control board is suitable for time-division control of their on / off states. Wherein, the main control board controls the second relay to open while closing the first relay, so that the first acquisition module can acquire the first voltage value on the first voltage divider resistor; after receiving the first voltage value, the main control board disconnects the first relay and closes the second relay, so that the second acquisition module can acquire the second voltage value on the second voltage divider resistor; the main control board calculates the insulation resistance of the positive high voltage line grounding and the insulation resistance of the negative high voltage line grounding based on the first voltage value and the second voltage value.

2. The ship system insulation resistance detection circuit according to claim 1, characterized in that, The first acquisition module includes: an isolation amplifier and an operational amplifier; The first acquisition terminal of the isolation amplifier is connected to the input terminal of the first voltage divider resistor, and the second acquisition terminal of the isolation amplifier is connected to the output terminal of the first voltage divider resistor; The first output terminal of the isolation amplifier is connected to the first input terminal of the operational amplifier, the second output terminal of the isolation amplifier is connected to the second input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the input terminal of the main control board.

3. The ship system insulation resistance detection circuit according to claim 2, characterized in that, It also includes a first isolated power supply module; The input terminal of the first isolated power supply module is adapted to be electrically connected to the output terminal of the ship's DC system, and the output terminal of the first isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the first acquisition module, respectively.

4. The ship system insulation resistance detection circuit according to claim 3, characterized in that, Also includes: Second isolation power supply module; The input terminal of the second isolated power supply module is adapted to be electrically connected to the output terminal of the ship's DC system, and the output terminal of the second isolated power supply module is electrically connected to the positive power supply pin and the ground power supply pin of the second acquisition module, respectively.

5. The ship system insulation resistance detection circuit according to claim 1, characterized in that, It also includes a first control circuit; The output terminal of the first control circuit is electrically connected to the control terminal of the first relay, and the input terminal of the first control circuit is electrically connected to the output terminal of the main control board. The main control board is adapted to output control signals to the first relay through the first control circuit.

6. The ship system insulation resistance detection circuit according to claim 5, characterized in that, The first control circuit also includes a first NMOS transistor; The gate (G) of the first NMOS transistor is electrically connected to the output terminal of the main control board, and the drain (D) of the first NMOS transistor is electrically connected to the control terminal of the first relay.

7. The ship system insulation resistance detection circuit according to claim 1, characterized in that, It also includes a second control circuit; The output terminal of the second control circuit is electrically connected to the control terminal of the second relay, and the input terminal of the second control circuit is electrically connected to the main control board.

8. The ship system insulation resistance detection circuit according to claim 7, characterized in that, The second control circuit also includes a second NMOS transistor; The gate (G) of the second NMOS transistor is electrically connected to the output terminal of the main control board, and the drain (D) of the second NMOS transistor is electrically connected to the control terminal of the second relay.

9. The ship system insulation resistance detection circuit according to claim 2, characterized in that, It also includes filter capacitors; One end of the filter capacitor is connected to the first input terminal of the operational amplifier, and the other end of the filter capacitor is connected to the output terminal of the operational amplifier.

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