Output voltage control circuit of a DC power supply module and a DC power supply system

Abstract

The present invention discloses an output voltage control circuit of a DC power supply module, including an optocoupler U1; the first pin of the optocoupler U1 is connected to the power supply module state input port V0; the second pin and the third pin of U1 intersect at the endpoint M; M is respectively connected to the source S of R2, C1 and the field effect tube V1; the endpoint M is connected to the signal ground; the fourth pin of U1 is respectively connected to the gate G of R1, R2, C1 and V1; R1 is connected to the first pin of the relay JK1; the second pin of JK1 is connected to the drain D of V1; the third pin of JK1 is connected to the positive output end of the original current sharing circuit in the power supply module; the fourth pin of JK1 is connected to the positive current sharing bus of the DC power supply system. The present invention discloses a DC power supply system. By applying the present invention, when a fault occurs in the DC power supply module or a newly replaced power supply module is started, the abnormal situation of pulling down or raising the module output voltage can be avoided, thereby improving the system reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit design, and in particular to an output voltage control circuit of a direct current power supply module and a direct current power supply system. Background Art

[0002] At present, in the DC power supply system, it is necessary to use an N+1 redundant structure to increase the reliability of the system power supply, where N is a natural number greater than 0. Figure 1 As shown, for N power modules (i.e., multiple power modules) in a DC power supply system, in order to avoid a large difference in the output power of each power module and increase the service life of the power module, a current balancing circuit is added to the power module to exert the current balancing function to ensure the balance of the output power of each power module.

[0003] exist Figure 1 In the example, the positive output terminal a+ and the negative output terminal a- of each power module are connected in parallel to supply power to the load. Each power module is provided with a positive current sharing control interface b+ and a negative current sharing control interface b-, and the internal current sharing circuit of the power module is connected to the positive current sharing control bus B+ and the negative current sharing control bus B- in the DC power supply system through the interfaces b+ and b-.

[0004] However, due to the increase of the current sharing circuit, when an online power module X fails or a newly replaced power module Y starts, at this time, the power module X or Y needs to temporarily exit the current sharing function. Otherwise, when the power module fails or the newly replaced power module starts, since these power modules X or Y have no power output, but the current sharing function of the power module X or Y is still working, it will cause an abnormal situation of lowering or raising the actual output voltage of the original online power modules except X or Y, thereby affecting the power supply reliability of the entire DC power supply system. Summary of the invention

[0005] The purpose of the present invention is to provide an output voltage control circuit of a DC power supply module and a DC power supply system in view of the technical defects in the prior art.

[0006] To this end, the present invention provides an output voltage control circuit of a DC power supply module, which is used in a power supply module in a DC power supply system. The circuit includes an optical coupler U1;

[0007] The first pin of the optocoupler U1 is connected to the power module status input port V0;

[0008] The second pin and the third pin of the optocoupler U1 intersect at the terminal M at the confluence;

[0009] The terminal M is respectively connected to one end of the resistor R2, one end of the capacitor C1 and the source S of the field effect transistor V1;

[0010] Terminal M is also connected to the signal ground;

[0011] The fourth pin of the optocoupler U1 is respectively connected to one end of the resistor R1, the other end of the resistor R2, the other end of the capacitor C1 and the gate G of the field effect transistor V1;

[0012] The other end of resistor R1 is connected to pin 1 of relay JK1 and to a 12V DC power supply;

[0013] The second pin of relay JK1 is connected to the drain D of field effect transistor V1;

[0014] The third pin of relay JK1 is connected to the original positive current sharing control interface b+ in the power module;

[0015] The 4th pin of relay JK1 is connected to the positive current sharing control bus B+ in the DC power supply system.

[0016] Preferably, the field effect transistor V1 is an NMOS field effect transistor.

[0017] Preferably, the relay JK1 is a normally open relay.

[0018] In addition, the present invention also discloses a DC power supply system, which includes a plurality of power supply modules connected in parallel;

[0019] The negative current sharing control interface b- of each power module is respectively connected to the negative current sharing control bus B- in the DC power supply system;

[0020] Each power module is used to provide working power for the connected load;

[0021] The output voltage control circuit of the DC power supply module as described above is connected between the positive current sharing control interface b+ of each power supply module and the positive current sharing control bus B+ in the DC power supply system.

[0022] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides an output voltage control circuit of a DC power supply module and a DC power supply system, which have a scientific structural design and are applied to a DC power supply system. When a power supply module fails or a newly replaced power supply module is started, it can avoid the abnormal situation of lowering or raising the actual output voltage of these online power modules, thereby improving the power supply reliability of the entire DC power supply system, which has great production practice significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1It is a structural block diagram of an existing DC power supply system;

[0024] Figure 2 A schematic diagram of an output voltage control circuit of a DC power supply module provided by the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0027] See also Figure 2 , the present invention provides an output voltage control circuit of a DC power supply module, which is used in a power supply module in a DC power supply system, and the circuit includes an optical coupler U1;

[0028] The first pin of the optocoupler U1 is connected to the power module status input port V0;

[0029] The 2nd and 4th pins of the optocoupler U1 intersect at the terminal M at the confluence;

[0030] The terminal M is respectively connected to one end of the resistor R2, one end of the capacitor C1 and the source S of the field effect transistor V1;

[0031] Terminal M is also connected to the signal ground;

[0032] The third pin of the optocoupler U1 is respectively connected to one end of the resistor R1, the other end of the resistor R2, the other end of the capacitor C1 and the gate G of the field effect transistor V1;

[0033] The other end of resistor R1 is connected to pin 1 of relay JK1 and to a 12V DC power supply;

[0034] The second pin of relay JK1 is connected to the drain D of field effect transistor V1;

[0035] The third pin of the relay JK1 is connected to the original positive current sharing control interface b+ in the power module (that is, the positive current sharing control interface b+ of the positive output end of the original current sharing circuit in the power module);

[0036] The 4th pin of relay JK1 is connected to the positive current sharing control bus B+ in the DC power supply system.

[0037] In the present invention, for specific implementation, see Figure 1As shown, for an existing DC power supply system, the positive current sharing control bus B+ in the DC power supply system is connected to the positive current sharing control interface b+ of each other power module in the external parallel system, which is used to adjust the output current of each power module to achieve a balanced power supply effect for each power module. By applying the present invention, a circuit designed by the present invention is added between the positive current sharing control bus B+ of the DC power supply system and the positive current sharing control interface b+ of each power module, specifically, the two pins of the relay JK1 are connected to the positive current sharing control bus B+ and the positive current sharing control interface b+, respectively.

[0038] It should be noted that after applying the circuit of the present invention, the original negative current sharing control interface b- in each power module (i.e., the negative current sharing control interface b- of the current sharing circuit in the power module for realizing the current sharing function) is directly connected to the negative current sharing control bus B- in the DC power supply system, and is used as the reference ground of the current sharing control circuit inside the power module. In other words, it is still the same as Figure 1 The same connection method is used to connect the original negative current sharing control interface b- in each power module and the negative current sharing control bus B- in the DC power supply system.

[0039] That is to say, the present invention does not adjust the connection method between the negative current sharing control interface b- of the power module and the negative current sharing control bus B- in the DC power supply system, but only adjusts the connection method between the positive current sharing control bus B+ of the DC power supply system and the positive current sharing control interface b+ of each power module, and the circuit structure of the present invention is added in between.

[0040] In the present invention, in a specific implementation, the field effect transistor V1 is an insulated gate field effect transistor (MOS transistor), specifically an NMOS field effect transistor.

[0041] In the present invention, in specific implementation, the relay JK1 is a four-pin relay, which is the most common single-pole single-throw relay and a normally open relay. Among them, the 1st and 2nd pins are coil terminals, and the 3rd and 4th pins are contact terminals. If the 1st and 2nd pins are energized, the coil in the relay is energized, the internal mechanical transmission is performed, and the 3rd and 4th pins (i.e., the contacts) are closed; if the 1st and 2nd pins are de-energized, the coil is de-energized, the internal mechanical transmission is performed, and the 3rd and 4th pins (i.e., the contacts) are opened.

[0042] In specific implementation, it should be noted that the optocoupler U1 is a common optocoupler, such as TLP521, TLP621 and other models produced by Toshiba, British Advanced Optical, and Youtai Semiconductor. Optocouplers not limited to the above companies and models can be applied to this technical solution. The optocoupler U1 mainly plays an isolation role in the present invention, so there is no special requirement for the manufacturer and model.

[0043] For the optocoupler U1, its first pin is the anode of the light-emitting diode inside the optocoupler, its second pin is the cathode of the light-emitting diode inside the optocoupler, its third pin is the emitter of the phototransistor inside the optocoupler, and its fourth pin is the collector of the phototransistor inside the optocoupler.

[0044] In terms of specific implementation, it should be noted that for relay JK1, it is an ordinary DC relay, such as the HF115F series of Xiamen Hongfa, which meets the voltage requirements in the circuit and has at least one set of normally open contacts, which can be applied to the present invention. Therefore, there are no special requirements for manufacturers and models.

[0045] For relay JK1, its first pin is the relay coil power supply + terminal, its second pin is the relay coil power supply - terminal, its third pin is one end of the relay normally open contact, and its fourth pin is the other end of the relay normally open contact.

[0046] In the present invention, in a specific implementation, the power module state input port V0 is connected to the original state output port on the power module to receive the state level signal output by the power module. When the power module is in a normal state, the state level signal is a low level, and when the power module is in a fault state, the state level signal is a high level.

[0047] For the present invention, it should be noted that the power module status input port V0 is specifically connected to an indication port on an existing power module for indicating whether the power module is in a normal state or a fault state. Among them, the fault state includes module overtemperature, input abnormality, output overvoltage and other faults.

[0048] In the present invention, the power module status input port V0 signal is the input end of the circuit of the present invention. When the power module is normal, the signal received by the power module status input port V0 is low level, and the current sharing function is involved in the work. When the power module is abnormal, the signal received by the power module status input port V0 is high level, and the current sharing part circuit is separated from the parallel current sharing control system.

[0049] It should be noted that for the original power module, the fault detection submodule inside the power module can realize the logic or function of the module over-temperature, input abnormality, output over-voltage and other faults existing in the power module. In the event of a fault, a high level is output to V0. In normal conditions, a low level is output.

[0050] In specific implementation, the fault detection submodule or the power module with fault detection function is an existing power module, for example, the power module model MW1-Z24 / 60 produced by Tianjin Railway Signal Co., Ltd. (i.e., a 24 volt, 60 ampere power module) can be used. Of course, it can also be a power module produced by other companies, as long as the power module can output a high-level signal to the outside (for example, output to the power module status input port V0 in the circuit of the present invention) when a fault occurs, and output a low-level signal to the outside (for example, output to the power module status input port V0 in the circuit of the present invention) when it is normal.

[0051] In the present invention, the original current balancing circuit in the power module can be realized by an integrated circuit, for example, it can be realized by using TI's UCC39002, UCC29002, UC3902, UC2902, UC3907, UC2907 series current balancing chips and simple peripheral circuits; the current balancing function can also be realized by digital control chip software, and the circuit of the patent of the present invention can be applied.

[0052] In the present invention, in a specific implementation, in the circuit, the resistor R2 is the ground resistance of the gate G of the field effect tube V1, which prevents the field effect tube V1 from malfunctioning in the air. The values ​​of the resistor R1 and the capacitor C1 need to be slowly charged according to the slow start time of the power module itself to achieve startup delay current sharing. When the power module fails, the optocoupler U1 is turned on to quickly discharge the capacitor C1, and the field effect tube V1 is turned off, so that the relay coil loses power and the electric contact is disconnected, thereby achieving rapid isolation of the faulty power module, thereby ensuring the normal operation of the entire DC power supply system.

[0053] Based on the output voltage control circuit of a DC power supply module provided by the present invention, the present invention further provides a DC power supply system, which includes a plurality of power supply modules connected in parallel;

[0054] Among them, see also Figure 1 , the negative current sharing control interface b- of each power module is respectively connected to the negative current sharing control bus B- in the DC power supply system;

[0055] Each power module is used to provide working power for the connected load;

[0056] It should be noted that the positive output terminal a+ and the negative output terminal a- of each power module are connected to the two ends (i.e., the positive terminal and the negative terminal) of the load respectively;

[0057] The positive current sharing control interface b+ of each power module is connected to the positive current sharing control bus B+ in the DC power supply system. Figure 2The output voltage control circuit of the DC power supply module is shown.

[0058] In order to more clearly understand the technical solution of the present invention, the working principle of the present invention is explained below.

[0059] For each power module in the DC power supply system, the positive current sharing control interface b+ (such as Figure 2 shown) and the positive current sharing control bus B+ (i.e. Figure 2 The current-sharing bus B+ in the power module is isolated by relay JK1. When the power module is normal, the power module status input port V0 receives the low level output by the power module, and when the power module fails, it receives the high level output by the power module.

[0060] 1. When a power module fails, the status output port on the power module outputs a high level to the status input port V0 of the power module, the optocoupler U1 is turned on, the secondary of the optocoupler U1 pulls down the voltage divided by the resistors R1 and R2, the capacitor C1 voltage is 0V, the field effect tube V1 is turned off, and the relay JK1 is disconnected. The positive current sharing control interface b+ of the original current sharing circuit (i.e., the circuit that realizes the balancing function) in the power module is isolated from the positive current sharing control bus B+ signal in the DC power supply system. The faulty power module is disconnected from the current sharing function, that is, the current sharing circuit interrupts the output.

[0061] 2. When the online power supply module is working, when the newly replaced power supply module participates in the startup, the status output port on the power supply module outputs a low level to the power supply module status input port V0, the secondary of the optocoupler U1 is not conducting, and the capacitor C1 starts to charge through the resistor R1. The charging time of the capacitor C1 needs to be greater than the working time from the slow start to the normal output of the power supply module. After the output voltage of the power supply module has reached the set value, the voltage of the capacitor C1 reaches the conduction voltage of the field effect tube V1, V1 is turned on, the relay JK1 is turned on, and the positive current sharing control interface b+ of the original current sharing circuit (that is, the circuit that realizes the balancing function) in the power supply module is connected to the positive current sharing control bus B+ in the DC power supply system. At this time, the original balancing circuit in the power supply module works normally and participates in the current sharing function.

[0062] To sum up, compared with the prior art, the output voltage control circuit of a DC power supply module and a DC power supply system provided by the present invention have a scientific structural design. When applied to a DC power supply system, when a power module fails or a newly replaced power module is started, it can avoid the abnormal situation of lowering or raising the actual output voltage of these online power modules, thereby improving the power supply reliability of the entire DC power supply system, which has great production practice significance.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An output voltage control circuit of a DC power supply module, characterized in that: Used on the power module in the DC power supply system, the circuit is arranged between the positive current sharing control interface b+ of the power module and the positive current sharing control bus B+ in the DC power supply system, and is used to control whether the current sharing circuit in the power module continues to play the current sharing function according to the working state of the power module, and the circuit includes an optical coupler U1; The first pin of the optocoupler U1 is connected to the power module status input port V0; The second pin and the third pin of the optocoupler U1 intersect at the terminal M at the confluence; The terminal M is respectively connected to one end of the resistor R2, one end of the capacitor C1 and the source S of the field effect transistor V1; Terminal M is also connected to the signal ground; The fourth pin of the optocoupler U1 is respectively connected to one end of the resistor R1, the other end of the resistor R2, the other end of the capacitor C1 and the gate G of the field effect transistor V1; The other end of resistor R1 is connected to pin 1 of relay JK1 and to a 12V DC power supply; The second pin of relay JK1 is connected to the drain D of field effect transistor V1; The third pin of relay JK1 is connected to the original positive current sharing control interface b+ in the power module; The 4th pin of relay JK1 is connected to the positive current sharing control bus B+ in the DC power supply system; The power module state input port V0 is connected to the original state output port on the power module, and is used to receive the state level signal output by the fault detection submodule inside the power module. When the power module is in a normal state, the state level signal is a low level, and when the power module is in a fault state, the state level signal is a high level; The power module status input port V0 is also used to output a high-level status level signal to the optocoupler U1 when a power module fails, so that the optocoupler U1 is turned on, and the capacitor C1 is discharged by turning on the optocoupler U1. The voltage of the capacitor C1 is 0V, so that the field effect tube V1 is turned off, and then the relay coil is de-energized and the contacts are disconnected, thereby isolating the faulty power module and causing the current sharing circuit in the power module to stop continuing to perform the current sharing function, thereby ensuring the normal operation of the entire DC power supply system.

2. The output voltage control circuit of the DC power supply module according to claim 1, characterized in that: The field effect transistor V1 is an NMOS field effect transistor.

3. The output voltage control circuit of the DC power supply module according to claim 1, characterized in that: Relay JK1 is a normally open relay.

4. A DC power supply system, characterized in that: It includes a plurality of power modules connected in parallel with each other; The negative current sharing control interface b- of each power module is respectively connected to the negative current sharing control bus B- in the DC power supply system; Each power module is used to provide working power for the connected load; An output voltage control circuit of a DC power supply module according to any one of claims 1 to 3 is connected between the positive current sharing control interface b+ of each power supply module and the positive current sharing control bus B+ in the DC power supply system.

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