EMI filter circuit and DC / DC power supply module based on EMI filter circuit

Abstract

The utility model relates to an EMI filter circuit and a DC / DC power supply module based on the EMI filter circuit, and the EMI filter circuit comprises an EMI filter circuit, an LLC voltage conversion and synchronous rectification output circuit, an auxiliary power supply circuit, a main control circuit and a signal processing circuit, and the EMI filter circuit is connected with the LLC voltage conversion and synchronous rectification output circuit and the auxiliary power supply circuit. The LLC voltage conversion and synchronous rectification output circuit and the auxiliary power supply circuit are connected with the main control circuit and the signal processing circuit; the digitally-controlled multi-module parallel multi-output DC / DC power supply module not only accords with the technical specification of a harmonious locomotive and is compatible with communication and input and output interfaces of an original locomotive power supply cabinet, but also greatly improves the working reliability of a power supply, reduces the probability of equipment overhaul and maintenance, and completes the intelligentization of the power supply cabinet.

Description

Technical Field

[0001] The present invention relates to the field of power supplies, and in particular to an EMI filter circuit and a DC / DC power supply module based on the circuit. Background Art

[0002] The power cabinet on the existing SS4B locomotive adopts analog electronic technology, which can provide precise voltage and current control, and ensure that the power can be stably output to provide appropriate power to various motors and electronic equipment under different load conditions including starting, running and braking. When the power module using analog electronic technology provides stable and reliable power for various electronic equipment, a large number of electronic components are used. Therefore, the locomotive power cabinet cannot work normally after a single device failure, or the power semiconductor generates a lot of heat, resulting in energy loss and low power conversion efficiency. In addition, the low intelligence of the internal component status of the power cabinet cannot be monitored, resulting in unforeseen failures, which requires frequent disassembly and maintenance, consuming huge manpower costs and maintenance costs. Summary of the invention

[0003] In view of this, the utility model provides an EMI filter circuit and a DC / DC power supply module based on the circuit, which effectively solves the technical defects of the existing power cabinet, such as the inability to monitor the status, high failure rate, and frequent manual maintenance.

[0004] To achieve the above purpose, the utility model provides an EMI filter circuit, including an EMC circuit, a buffer circuit, a relay cut-off circuit and a rectifier filter circuit; the EMC circuit is connected to the buffer circuit, and the buffer circuit is connected to the relay cut-off circuit and the rectifier filter circuit.

[0005] As a further improvement of the above solution:

[0006] Preferably, the EMC circuit includes a first capacitor CX1, a second capacitor CX2, a third capacitor CY1, a fourth capacitor CY2, a fuse F1, a varistor RV1, a common mode inductor L1, a first inductor L2 and a second inductor L3; two ends of the first capacitor CX1 are connected to a power input terminal and a ground wire, one end of the fuse F1 is connected to one end of the first capacitor CX1, the other end of the fuse F1 is connected to one end of the varistor RV1, the other end of the varistor RV1 is connected to the ground wire, one end of the first inductor L2 is connected to a connection point between the varistor RV1 and the fuse F1, and the One end of the second inductor L3 is connected to the connection point of the varistor RV1 and the first capacitor CX1, the other end of the first inductor L2 is connected to the contact 1 of the common-mode inductor L1, one end of the third capacitor CY1 is connected to the contact 2 of the common-mode inductor L1, the other end of the second inductor L3 is connected to the contact 3 of the common-mode inductor L1, the connection point of the second capacitor CX2 and the fourth capacitor CY2 is connected to the contact 4 of the common-mode inductor L1, the third capacitor CY1 and the fourth capacitor CY2 are respectively connected to the ground line, and both ends of the second capacitor CX2 are respectively connected to the third capacitor CY1 and the fourth capacitor CY2.

[0007] Preferably, the buffer circuit includes a first varistor RT1, a second varistor RT2, a fifth capacitor C2, and a sixth capacitor C3, the first varistor RT1 is connected in parallel with the fifth capacitor C2 and one end is connected to the connection point of the second capacitor CX2 and the third capacitor CY1, the other connection point of the first varistor RT1 and the fifth capacitor C2 is connected to the sixth capacitor C3, and one end of the second varistor RT2 is connected to the connection point of the first varistor RT1 and the fifth capacitor C2.

[0008] Preferably, the relay cut-off circuit includes a first relay K1, a second relay K2, a first diode D1, a second diode D2, a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4, the first relay K1 is connected in parallel with the first diode D1 and one end is connected to the 12V voltage terminal, the connection point of the first relay K1 and the other end of the first diode D1 is connected to the drain of the first transistor Q1, the source of the first transistor Q1 is connected to the ground terminal, and the gate of the first transistor Q1 is connected to the first resistor R1 and the second resistor R2 , the other end of the first resistor R1 is connected to the ground, the second resistor R2 is connected to the thermal relay NTC-Relay end, the second relay K2 is connected to the second diode D2 in parallel and one end is connected to the 12V voltage end, the connection point of the second relay K2 and the other end of the second diode D2 is connected to the drain of the second transistor Q2, the gate of the second transistor Q2 is connected to the third resistor R3 and the fourth resistor R4, the source of the second transistor Q2 is connected to the ground, the other end of the third resistor R3 is connected to the ground, and the fourth resistor R4 is connected to the pre-relay PRO-Relay end;

[0009] The first relay K1 includes a single-pole double-throw switch relay Relay-SPDT, the switch end of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1 and one end of the fifth capacitor C2, one contact of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1, and the other contact of the single-pole double-throw switch relay Relay-SPDT is disconnected; the second relay K2 includes a double-pole double-throw switch relay Relay-DPDT, the two switch ends of the double-pole double-throw switch relay Relay-DPDT are connected in parallel and connected to one end of the sixth capacitor C3, one contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is connected to one end of the sixth capacitor C3, and the other contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is disconnected.

[0010] Preferably, the rectifier and filter circuit includes a seventh capacitor C4, an eighth capacitor C5, a ninth capacitor C6, a tenth capacitor C7, an eleventh capacitor C8, a twelfth capacitor C9, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 are connected in parallel, a connection point of one end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to one end of the fifth resistor R5 and to the DC voltage end, a connection point of the other end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to the DC ground line, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and to the output end, and the other end of the seventh resistor R7 is connected to the eighth resistor R8 and to the DC ground line;

[0011] The tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 are connected in parallel, a connection point of one end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the auxiliary voltage input terminal, and a connection point of the other end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the ground terminal of the auxiliary voltage.

[0012] Preferably, the EMI circuit also includes two anti-reverse connection and maintenance circuits, and the two ends of the anti-reverse connection and maintenance circuits are respectively connected to the buffer circuit and the rectifier and filter circuit; the anti-reverse connection and maintenance circuit uses a rectifier bridge stack, an AC interface of the rectifier bridge stack is connected to the sixth capacitor C3 of the buffer circuit, and another AC interface of the rectifier bridge stack is connected to the connection point of the second capacitor CX2 and the fourth capacitor CY2 in the buffer circuit, the V+ interface of the rectifier bridge stack is connected to the connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 in the rectifier and filter circuit, and the V- interface of the rectifier bridge stack is connected to another connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6.

[0013] Preferably, the EMI circuit also includes an anti-reverse connection and maintenance circuit, and the two ends of the anti-reverse connection and maintenance circuit are respectively connected to the buffer circuit and the auxiliary power supply circuit; the anti-reverse connection and maintenance circuit uses a rectifier bridge stack, an AC interface of the rectifier bridge stack is connected to the connection point of the second capacitor CX2 and the fourth capacitor CY2 in the buffer circuit, and another AC interface of the rectifier bridge stack is connected to the second varistor RT2 in the buffer circuit, the V+ interface of the rectifier bridge stack is connected to the input end of the auxiliary power supply circuit, and the V- interface of the rectifier bridge stack is connected to the ground end of the auxiliary power supply circuit.

[0014] The utility model also provides a DC / DC power supply module, a DC / DC power supply module having the EMI filter circuit, and also comprising an LLC voltage conversion and output synchronous rectification circuit, an auxiliary power supply circuit, a main control circuit and a signal processing circuit; the EMI filter circuit is connected to the LLC voltage conversion and synchronous rectification output circuit and the auxiliary power supply circuit, and the LLC voltage conversion and synchronous rectification output circuit is connected to the auxiliary power supply circuit, the main control circuit and the signal processing circuit.

[0015] Preferably, the auxiliary power supply circuit includes a thirteenth capacitor C12, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a common-mode inductor L2, and a DC power supply U1; the seventeenth capacitor C17 and the eighteenth capacitor C18 are connected in parallel, and the connection point of one end of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V voltage terminal and connected to the common-mode inductor L2. 2, the other end connection point of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V ground terminal and connected to the contact 4 of the common-mode inductor L2, the fourteenth capacitor C14 is connected in parallel with the nineteenth capacitor C19, the connection point of one end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the contact 2 of the common-mode inductor L2 and the Vi+ interface of the DC power supply U1, the connection point of the other end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the contact 2 of the common-mode inductor L2 and the Vi+ interface of the DC power supply U1, The contact 3 is connected to the Vi- interface of the DC power supply U1, the two ends of the thirteenth capacitor C12 are respectively connected to the Vi+ interface and the Vo+ interface of the DC power supply U1, the two ends of the twentieth capacitor C20 are respectively connected to the Vi- interface and the Vo- interface of the DC power supply, the fifteenth capacitor C15 is connected in parallel with the sixteenth capacitor C16, the connection point of one end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the 24V voltage end and connected to the Vo+ interface of the DC power supply U1, and the connection point of the other end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the ground end and connected to the Vo- interface of the DC power supply U1; the auxiliary power supply has three, namely, the input end MOS drive circuit power supply, the output end current and voltage detection circuit power supply and the MCU control circuit power supply, the input end MOS drive circuit power supply is connected to the EMI circuit, the output end current and voltage detection circuit power supply is connected to the LLC voltage conversion and output synchronous rectification circuit, and the MCU control circuit power supply is connected to the main control circuit and the signal processing circuit.

[0016] Preferably, the LLC voltage conversion and synchronous rectification output circuit internally includes a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, a cooling fan power supply control circuit, a temperature control circuit, an output voltage detection circuit, an output current detection circuit, an output filter circuit, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor Cr, a third inductor Lr, a fourth inductor LM, a fifth inductor Ll, a transformer T1, a first MOS tube S1, a second MOS tube S2, a third MOS tube S3, a fourth MOS tube S4 and a third relay switch The power control circuit is connected to a third relay switch K, the third relay switch K is connected to an input voltage detection circuit, the input voltage detection circuit is connected to an input current detection circuit, the twenty-first capacitor C21 and the twenty-second capacitor C22 are connected in series and connected in parallel to the input voltage detection circuit, the drain of the third MOS tube S3 is connected to the twenty-first capacitor C21, the source of the third MOS tube S3 is connected to the drain of the fourth MOS tube S4, the gate of the third MOS tube S3 and the gate of the fourth MOS tube S4 are connected to a half-bridge drive circuit, and the third The source of the fourth MOS tube S4 is connected to one end of the twenty-second capacitor C22 and connected to the EMI filter circuit, one end of the twenty-third capacitor Cr is connected to the connection point of the third MOS tube S3 and the fourth MOS tube S4, the other end of the twenty-third capacitor Cr is connected to one end of the third inductor Lr, the other end of the third inductor Lr is connected to the output current detection circuit, one end of the fourth inductor LM is connected to the output current detection circuit, the other end of the fourth inductor LM is connected to the connection point of the twenty-first capacitor C21 and the twenty-second capacitor C22, and the primary line of the transformer T1 is connected to the output current detection circuit. Two ends of the coil are connected in parallel with the fourth inductor LM, the drain of the first MOS transistor S1 is connected to one end of the secondary coil of the transformer T1, the source of the first MOS transistor S1 is connected to the source of the second MOS transistor S2, the drain of the second MOS transistor S2 is connected to the other end of the secondary coil of the transformer T1, one end of the fifth inductor L1 is connected to the secondary coil of the transformer T1, the other end of the fifth inductor L1 is connected to the output filter circuit, the other end of the output filter circuit is connected to the output voltage detection circuit and to the user load, and the output current detection circuit is connected to the user load VG end.

[0017] Preferably, the main control circuit and the signal processing circuit include an MCU control circuit, a module address bit setting circuit and an external communication circuit. The MCU control circuit is connected to an auxiliary power supply circuit. The MCU control circuit is connected to a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, an output current detection circuit, and a cooling fan power supply control circuit in an LLC voltage conversion and output synchronous rectification circuit. The MCU control circuit is further connected to a temperature control circuit, an output voltage detection circuit, and an output current detection circuit; the external communication circuit includes a CAN communication interface circuit, and the CAN communication interface circuit and the module address bit setting circuit are connected to the MCU control circuit.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. Digital electronic technology has replaced the existing analog electronic technology. The parameters of each electronic component can be set by programming to reduce the possibility of redundant power supply and high failure rate.

[0020] 2. The digital power supply can integrate monitoring functions to realize real-time monitoring of the operating status of the power supply, including parameters such as temperature, current, and voltage. It can also self-adjust the working mode according to the monitoring parameters to adapt to changes in the external environment or fault conditions, greatly reducing the possibility of machine damage caused by the failure of a single device causing the locomotive power cabinet to fail to work normally.

[0021] 3. Digital power technology has self-diagnosis function, which can detect and report potential problems in time, improve the predictability of faults, improve the intelligence of power modules, and reduce the labor cost of inspection and maintenance.

[0022] 4. Digital power technology uses precise digital control algorithms that dynamically adjust according to load changes to achieve higher power conversion efficiency and more stable voltage output, reducing energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is an electrical principle block diagram of a DC / DC power supply module described in the utility model;

[0025] Figure 2 This is a module system diagram of a DC / DC power supply module described in the utility model;

[0026] Figure 3 This is an EMI filter circuit diagram described in the utility model;

[0027] Figure 4 This is the auxiliary power supply circuit diagram of the utility model. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0029] The utility model provides the following technical solutions:

[0030] like Figure 1-Figure 4 The utility model provides an EMI filter circuit, a DC / DC power supply module has the EMI filter circuit, the EMI filter circuit includes an EMC circuit, a buffer circuit, a relay cut-off circuit and a rectifier filter circuit; the EMC circuit is connected to the buffer circuit, and the buffer circuit is connected to the relay cut-off circuit and the rectifier filter circuit.

[0031] The EMC circuit includes a first capacitor CX1, a second capacitor CX2, a third capacitor CY1, a fourth capacitor CY2, a fuse F1, a varistor RV1, a common mode inductor L1, a first inductor L2 and a second inductor L3; two ends of the first capacitor CX1 are connected to a power input end and a ground line, one end of the fuse F1 is connected to one end of the first capacitor CX1, the other end of the fuse F1 is connected to one end of the varistor RV1, the other end of the varistor RV1 is connected to the ground line, one end of the first inductor L2 is connected to the connection point of the varistor RV1 and the fuse F1, one end of the second inductor L3 is connected to the varistor RV1 and the first capacitor C The connection points of the second and fourth capacitors CY1 and CY2 are connected to the ground line respectively, and the two ends of the second capacitor CX2 are connected to the third capacitor CY1 and the fourth capacitor CY2 respectively; the EMC circuit design passes the line-to-line 1kV and line-to-ground 2kV surge tests and meets the electromagnetic interference standards.

[0032] The buffer circuit includes a first varistor RT1, a second varistor RT2, a fifth capacitor C2, and a sixth capacitor C3. The first varistor RT1 is connected in parallel with the fifth capacitor C2 and one end of the first varistor is connected to the connection point between the second capacitor CX2 and the third capacitor CY1. Another connection point between the first varistor RT1 and the fifth capacitor C2 is connected to the sixth capacitor C3. One end of the second varistor RT2 is connected to the connection point between the first varistor RT1 and the fifth capacitor C2.

[0033] The relay cut-off circuit includes a first relay K1, a second relay K2, a first diode D1, a second diode D2, a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4. The first relay K1 is connected in parallel with the first diode D1 and one end is connected to the 12V voltage terminal. The connection point of the first relay K1 and the other end of the first diode D1 is connected to the drain of the first transistor Q1. The source of the first transistor Q1 is connected to the ground terminal. The gate of the first transistor Q1 is connected to the first resistor R1 and the second resistor R2. The other end of the first resistor R1 is connected to the ground, the second resistor R2 is connected to the thermal relay NTC-Relay, the second relay K2 is connected to the second diode D2 in parallel and one end is connected to the 12V voltage terminal, the connection point between the second relay K2 and the other end of the second diode D2 is connected to the drain of the second transistor Q2, the gate of the second transistor Q2 is connected to the third resistor R3 and the fourth resistor R4, the source of the second transistor Q2 is connected to the ground, the other end of the third resistor R3 is connected to the ground, and the fourth resistor R4 is connected to the pre-relay PRO-Relay.

[0034] The first relay K1 includes a single-pole double-throw switch relay Relay-SPDT, the switch end of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1 and one end of the fifth capacitor C2, one contact of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1, and the other contact of the single-pole double-throw switch relay Relay-SPDT is disconnected; the second relay K2 includes a double-pole double-throw switch relay Relay-DPDT, the two switch ends of the double-pole double-throw switch relay Relay-DPDT are connected in parallel and connected to one end of the sixth capacitor C3, one contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is connected to one end of the sixth capacitor C3, and the other contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is disconnected.

[0035] The buffer circuit limits the initial current through the second varistor RT2. When the fifth capacitor C2 is charged to 80% and the power module has started working, the MCU control circuit controls the first relay K1 and the second relay K2 contacts at both ends of the second varistor RT2 to close by comparing with the auxiliary circuit voltage through AD acquisition; the relay cut-off circuit is mainly used to cut off the connection between the main circuit and the input by cutting off the relay contacts when the power supply fails or the input is over-voltage or under-voltage, so as to prevent machine damage.

[0036] The rectifier and filter circuit includes a seventh capacitor C4, an eighth capacitor C5, a ninth capacitor C6, a tenth capacitor C7, an eleventh capacitor C8, a twelfth capacitor C9, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8. The seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 are connected in parallel. A connection point of one end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to one end of the fifth resistor R5 and to a DC voltage end. A connection point of the other end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to a DC ground line. The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and to the output end. The other end of the seventh resistor R7 is connected to the eighth resistor R8 and to the DC ground line.

[0037] The tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 are connected in parallel, the connection point of one end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the auxiliary voltage input terminal, and the connection point of the other end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the ground terminal of the auxiliary voltage.

[0038] The EMI circuit also includes an anti-reverse connection and maintenance circuit, and the two ends of the anti-reverse connection and maintenance circuit are respectively connected to the buffer circuit and the rectifier filter circuit; the anti-reverse connection and maintenance circuit uses a rectifier bridge stack, an AC interface of the rectifier bridge stack is connected to the sixth capacitor C3 of the buffer circuit, another AC interface of the rectifier bridge stack is connected to the connection point of the second capacitor CX2 and the fourth capacitor CY2 in the buffer circuit, the V+ interface of the rectifier bridge stack is connected to the connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 in the rectifier filter circuit, and the V- interface of the rectifier bridge stack is connected to another connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6; the anti-reverse connection and maintenance circuit provides stable direct current for the main circuit, and the full load current is 6.5A at 77V, which is 7.8A multiplied by a coefficient of 1.2; the rectifier bridge stack uses a GBJ2010 bridge stack, and the GBJ2010 rectifier bridge stack can provide 20A current.

[0039] The DC / DC power supply module includes an EMI filter circuit, an LLC voltage conversion and output synchronous rectification circuit, an auxiliary power supply circuit, a main control circuit and a signal processing circuit; the EMI filter circuit is connected to the LLC voltage conversion and output synchronous rectification circuit and the auxiliary power supply circuit, and the LLC voltage conversion and output synchronous rectification circuit and the auxiliary power supply circuit are connected to the main control circuit and the signal processing circuit.

[0040] The auxiliary power supply circuit includes a thirteenth capacitor C12, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a common-mode inductor L2, and a DC power supply U1; the seventeenth capacitor C17 is connected in parallel with the eighteenth capacitor C18, a connection point of one end of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V voltage terminal and connected to the contact 1 of the common-mode inductor L2, a connection point of the other end of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V ground terminal and connected to the contact 4 of the common-mode inductor L2, the fourteenth capacitor C14 is connected in parallel with the nineteenth capacitor C19, a connection point of one end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the common The contact 2 of the common-mode inductor L2 is connected to the Vi+ interface of the DC power supply U1, the connection point of the other end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the contact 3 of the common-mode inductor L2 and the Vi- interface of the DC power supply U1, the two ends of the thirteenth capacitor C12 are respectively connected to the Vi+ interface and the Vo+ interface of the DC power supply U1, the two ends of the twentieth capacitor C20 are respectively connected to the Vi- interface and the Vo- interface of the DC power supply, the fifteenth capacitor C15 and the sixteenth capacitor C16 are connected in parallel, the connection point of one end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the 24V voltage terminal and connected to the Vo+ interface of the DC power supply U1, and the connection point of the other end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the ground terminal and connected to the Vo- interface of the DC power supply U1.

[0041] The LLC voltage conversion and synchronous rectification output circuit includes a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, a cooling fan power supply control circuit, a temperature control circuit, an output voltage detection circuit, an output current detection circuit, an output filter circuit, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor Cr, a third inductor Lr, a fourth inductor LM, a fifth inductor Ll, a transformer T1, a first MOS tube S1, a second MOS tube S2, a third MOS tube S3, a fourth MOS tube S4 and a third relay switch K. The power control circuit is connected to the third relay switch K, the third relay switch K is connected to the input voltage detection circuit, the input voltage detection circuit is connected to the input current detection circuit, the twenty-first capacitor C21 and the twenty-second capacitor C22 are connected in series and connected in parallel to the input voltage detection circuit, the drain of the third MOS tube S3 is connected to the twenty-first capacitor C21, the source of the third MOS tube S3 is connected to the drain of the fourth MOS tube S4, the gate of the third MOS tube S3 and the gate of the fourth MOS tube S4 are connected to the half-bridge drive circuit, the source of the fourth MOS tube S4 and the twenty-second capacitor C22 are connected in series and connected in parallel to the input voltage detection circuit, the drain of the third MOS tube S3 is connected to the twenty-first capacitor C21, the source of the third MOS tube S3 is connected to the drain of the fourth MOS tube S4, the gate of the third MOS tube S3 and the gate of the fourth MOS tube S4 are connected to the half-bridge drive circuit, and the source of the fourth MOS tube S4 and the twenty-second capacitor C22 are connected in series. One end of the twenty-third capacitor Cr is connected to the connection point of the third MOS tube S3 and the fourth MOS tube S4, the other end of the twenty-third capacitor Cr is connected to one end of the third inductor Lr, the other end of the third inductor Lr is connected to the output current detection circuit, one end of the fourth inductor LM is connected to the output current detection circuit, the other end of the fourth inductor LM is connected to the connection point of the twenty-first capacitor C21 and the twenty-second capacitor C22, both ends of the primary coil of the transformer T1 are connected in parallel with the fourth inductor LM, and the drain of the first MOS tube S1 is connected to the drain of the first MOS tube S1. The first MOS tube S1 is connected to one end of the secondary coil of the transformer T1, the source of the first MOS tube S1 is connected to the source of the second MOS tube S2, the drain of the second MOS tube S2 is connected to the other end of the secondary coil of the transformer T1, one end of the fifth inductor L1 is connected to the secondary coil of the transformer T1, the other end of the fifth inductor L1 is connected to the output filter circuit, the other end of the output filter circuit is connected to the output voltage detection circuit and connected to the user load, and the output current detection circuit is connected to the user load VG end; the DC 110V power supply is converted into an isolated DC 24V power supply to provide power for emergency lights, instruments and other equipment.

[0042] There are three auxiliary power supplies, namely the input MOS drive circuit power supply, the output current and voltage detection circuit power supply and the MCU control circuit power supply. The input MOS drive circuit power supply is connected to the EMI circuit, the output current and voltage detection circuit power supply is connected to the LLC voltage conversion and output synchronous rectification circuit, and the MCU control circuit power supply is connected to the main control circuit and signal processing circuit. Since the main circuit needs to be cut off and the communication signal needs to be sent in case of over-voltage or under-voltage, the auxiliary power supply requires a relatively wide voltage range, ranging from DC60 to 150V±1V.

[0043] The main control circuit and the signal processing circuit include an MCU control circuit, a module address bit setting circuit and an external communication circuit. The MCU control circuit is connected to an auxiliary power supply circuit. The MCU control circuit is connected to a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, an output current detection circuit and a cooling fan power supply control circuit in an LLC voltage conversion and output synchronous rectification circuit. The MCU control circuit is further connected to a temperature control circuit, an output voltage detection circuit and an output current detection circuit. The external communication circuit includes a CAN communication interface circuit. The CAN communication interface circuit and the module address bit setting circuit are connected to the MCU control circuit. The MCU control part adopts a DSP and uses a chip of model TMS320F28027FPTQ (LQFP-48_7x7x05P). The external communication circuit uses chips of model NCP2515 (SCP-18) and TD301DCAN.

[0044] The power of a single DC / DC power module is 500W, with N+1 hot backup, a power cabinet system that complies with the technical specifications of the Harmony AC electric locomotive (HXD1B), and can directly replace modules without changing the locomotive hardware and mechanical structure.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An EMI filter circuit, characterized in that: It comprises an EMC circuit, a buffer circuit, a relay cut-off circuit and a rectifier filter circuit; the EMC circuit is connected to the buffer circuit, and the buffer circuit is connected to the relay cut-off circuit and the rectifier filter circuit.

2. An EMI filter circuit according to claim 1, characterized in that: The EMC circuit includes a first capacitor CX1, a second capacitor CX2, a third capacitor CY1, a fourth capacitor CY2, a fuse F1, a varistor RV1, a common mode inductor L1, a first inductor L2 and a second inductor L3; two ends of the first capacitor CX1 are connected to a power input terminal and a ground wire, one end of the fuse F1 is connected to one end of the first capacitor CX1, the other end of the fuse F1 is connected to one end of the varistor RV1, the other end of the varistor RV1 is connected to the ground wire, one end of the first inductor L2 is connected to a connection point between the varistor RV1 and the fuse F1, and the second One end of the inductor L3 is connected to the connection point of the varistor RV1 and the first capacitor CX1, the other end of the first inductor L2 is connected to the contact 1 of the common-mode inductor L1, one end of the third capacitor CY1 is connected to the contact 2 of the common-mode inductor L1, the other end of the second inductor L3 is connected to the contact 3 of the common-mode inductor L1, the connection point of the second capacitor CX2 and the fourth capacitor CY2 is connected to the contact 4 of the common-mode inductor L1, the third capacitor CY1 and the fourth capacitor CY2 are respectively connected to the ground line, and both ends of the second capacitor CX2 are respectively connected to the third capacitor CY1 and the fourth capacitor CY2.

3. The EMI filter circuit according to claim 1, characterized in that: The buffer circuit includes a first varistor RT1, a second varistor RT2, a fifth capacitor C2, and a sixth capacitor C3. The first varistor RT1 is connected in parallel with the fifth capacitor C2 and one end is connected to the connection point of the second capacitor CX2 and the third capacitor CY1. Another connection point between the first varistor RT1 and the fifth capacitor C2 is connected to the sixth capacitor C3. One end of the second varistor RT2 is connected to the connection point of the first varistor RT1 and the fifth capacitor C2.

4. The EMI filter circuit according to claim 1, characterized in that: The relay cut-off circuit includes a first relay K1, a second relay K2, a first diode D1, a second diode D2, a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4. The first relay K1 is connected in parallel with the first diode D1 and one end is connected to the 12V voltage end. The connection point of the first relay K1 and the other end of the first diode D1 is connected to the drain of the first transistor Q1. The source of the first transistor Q1 is connected to the ground end. The gate of the first transistor Q1 is connected to the first resistor R1 and the second resistor R2. The other end of the first resistor R1 is connected to the ground, the second resistor R2 is connected to the thermal relay NTC-Relay end, the second relay K2 is connected to the second diode D2 in parallel and one end is connected to the 12V voltage end, the connection point between the second relay K2 and the other end of the second diode D2 is connected to the drain of the second transistor Q2, the gate of the second transistor Q2 is connected to the third resistor R3 and the fourth resistor R4, the source of the second transistor Q2 is connected to the ground, the other end of the third resistor R3 is connected to the ground, and the fourth resistor R4 is connected to the pre-relay PRO-Relay end; The first relay K1 includes a single-pole double-throw switch relay Relay-SPDT, the switch end of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1 and one end of the fifth capacitor C2, one contact of the single-pole double-throw switch relay Relay-SPDT is connected to the first varistor RT1, and the other contact of the single-pole double-throw switch relay Relay-SPDT is disconnected; the second relay K2 includes a double-pole double-throw switch relay Relay-DPDT, the two switch ends of the double-pole double-throw switch relay Relay-DPDT are connected in parallel and connected to one end of the sixth capacitor C3, one contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is connected to one end of the sixth capacitor C3, and the other contact of the two switches of the double-pole double-throw switch relay Relay-DPDT is disconnected.

5. The EMI filter circuit according to claim 1, characterized in that: The rectifier and filter circuit includes a seventh capacitor C4, an eighth capacitor C5, a ninth capacitor C6, a tenth capacitor C7, an eleventh capacitor C8, a twelfth capacitor C9, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 are connected in parallel, a connection point of one end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to one end of the fifth resistor R5 and to a DC voltage end, a connection point of the other end of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 is connected to a DC ground line, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and to the output end, and the other end of the seventh resistor R7 is connected to the eighth resistor R8 and to the DC ground line; The tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 are connected in parallel, a connection point of one end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the auxiliary voltage input terminal, and a connection point of the other end of the tenth capacitor C7, the eleventh capacitor C8 and the twelfth capacitor C9 is connected to the ground terminal of the auxiliary voltage.

6. The EMI filter circuit according to claim 1, characterized in that: The EMI filtering circuit also includes two anti-reverse connection and maintenance circuits, and the two ends of the anti-reverse connection and maintenance circuits are respectively connected to the buffer circuit and the rectifier filtering circuit; the anti-reverse connection and maintenance circuit uses a rectifier bridge stack, an AC interface of the rectifier bridge stack is connected to the sixth capacitor C3 of the buffer circuit, and another AC interface of the rectifier bridge stack is connected to the connection point of the second capacitor CX2 and the fourth capacitor CY2 in the buffer circuit, the V+ interface of the rectifier bridge stack is connected to the connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6 in the rectifier filtering circuit, and the V- interface of the rectifier bridge stack is connected to another connection point of the seventh capacitor C4, the eighth capacitor C5 and the ninth capacitor C6.

7. A DC / DC power supply module, comprising the EMI filter circuit according to any one of claims 1 to 6, characterized in that: It also includes an LLC voltage conversion and output synchronous rectification circuit, an auxiliary power supply circuit, a main control circuit and a signal processing circuit; the EMI filter circuit is connected to the LLC voltage conversion and synchronous rectification output circuit and the auxiliary power supply circuit, and the LLC voltage conversion and synchronous rectification output circuit is connected to the auxiliary power supply circuit and the main control circuit and the signal processing circuit.

8. A DC / DC power supply module according to claim 7, characterized in that: The auxiliary power supply circuit includes a thirteenth capacitor C12, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, a twentieth capacitor C20, a common-mode inductor L2, and a DC power supply U1; the seventeenth capacitor C17 is connected in parallel with the eighteenth capacitor C18, the connection point of one end of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V voltage terminal and connected to the contact 1 of the common-mode inductor L2, the connection point of the other end of the seventeenth capacitor C17 and the eighteenth capacitor C18 is connected to the 110V ground terminal and connected to the contact 4 of the common-mode inductor L2, the fourteenth capacitor C14 is connected in parallel with the nineteenth capacitor C19, the connection point of one end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the common The contact 2 of the common-mode inductor L2 is connected to the Vi+ interface of the DC power supply U1, the connection point of the other end of the fourteenth capacitor C14 and the nineteenth capacitor C19 is connected to the contact 3 of the common-mode inductor L2 and the Vi- interface of the DC power supply U1, the two ends of the thirteenth capacitor C12 are respectively connected to the Vi+ interface and the Vo+ interface of the DC power supply U1, the two ends of the twentieth capacitor C20 are respectively connected to the Vi- interface and the Vo- interface of the DC power supply, the fifteenth capacitor C15 is connected in parallel with the sixteenth capacitor C16, the connection point of one end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the 24V voltage terminal and connected to the Vo+ interface of the DC power supply U1, and the connection point of the other end of the fifteenth capacitor C15 and the sixteenth capacitor C16 is connected to the ground terminal and connected to the Vo- interface of the DC power supply U1; The auxiliary power supplies include three: an input MOS drive circuit power supply, an output current and voltage detection circuit power supply, and an MCU control circuit power supply. The input MOS drive circuit power supply is connected to the EMI circuit, the output current and voltage detection circuit power supply is connected to the LLC voltage conversion and output synchronous rectification circuit, and the MCU control circuit power supply is connected to the main control circuit and the signal processing circuit.

9. The DC / DC power supply module according to claim 7, characterized in that: The LLC voltage conversion and synchronous rectification output circuit internally includes a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, a cooling fan power supply control circuit, a temperature control circuit, an output voltage detection circuit, an output current detection circuit, an output filter circuit, a twenty-first capacitor C21, a twenty-second capacitor C22, a twenty-third capacitor Cr, a third inductor Lr, a fourth inductor LM, a fifth inductor Ll, a transformer T1, a first MOS tube S1, a second MOS tube S2, a third MOS tube S3, a fourth MOS tube S4 and a third relay switch K. The power control circuit is connected to the third relay switch K, the third relay switch K is connected to the input voltage detection circuit, the input voltage detection circuit is connected to the input current detection circuit, the twenty-first capacitor C21 and the twenty-second capacitor C22 are connected in series and connected in parallel to the input voltage detection circuit, the drain of the third MOS tube S3 is connected to the twenty-first capacitor C21, the source of the third MOS tube S3 is connected to the drain of the fourth MOS tube S4, the gate of the third MOS tube S3 and the gate of the fourth MOS tube S4 are connected to the half-bridge drive circuit, and the fourth MOS tube S4 is connected to the half-bridge drive circuit. The source of the MOS tube S4 is connected to one end of the 22nd capacitor C22 and connected to the EMI filter circuit, one end of the 23rd capacitor Cr is connected to the connection point of the third MOS tube S3 and the fourth MOS tube S4, the other end of the 23rd capacitor Cr is connected to one end of the third inductor Lr, the other end of the third inductor Lr is connected to the output current detection circuit, one end of the fourth inductor LM is connected to the output current detection circuit, the other end of the fourth inductor LM is connected to the connection point of the 21st capacitor C21 and the 22nd capacitor C22, and the primary coil of the transformer T1 Two ends are connected in parallel with the fourth inductor LM, the drain of the first MOS transistor S1 is connected to one end of the secondary coil of the transformer T1, the source of the first MOS transistor S1 is connected to the source of the second MOS transistor S2, the drain of the second MOS transistor S2 is connected to the other end of the secondary coil of the transformer T1, one end of the fifth inductor L1 is connected to the secondary coil of the transformer T1, the other end of the fifth inductor L1 is connected to the output filter circuit, the other end of the output filter circuit is connected to the output voltage detection circuit and to the user load, and the output current detection circuit is connected to the user load VG end.

10. The DC / DC power supply module according to claim 7, characterized in that: The main control circuit and the signal processing circuit include an MCU control circuit, a module address bit setting circuit and an external communication circuit. The MCU control circuit is connected to an auxiliary power supply circuit. The MCU control circuit is connected to a power control circuit, an input voltage detection circuit, an input current detection circuit, a half-bridge drive circuit, an output current detection circuit, and a cooling fan power supply control circuit in an LLC voltage conversion and output synchronous rectification circuit. The MCU control circuit is further connected to a temperature control circuit, an output voltage detection circuit, and an output current detection circuit. The external communication circuit includes a CAN communication interface circuit. The CAN communication interface circuit and the module address bit setting circuit are connected to the MCU control circuit.

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