A power module and a power system

Abstract

The present invention discloses a power supply module and a power supply system, wherein the power supply module comprises: an output current feedback control circuit; the first output of the output rectifying and filtering unit serves as the first output (DC+) of the power supply module, the second output (VS) of the output rectifying and filtering unit is connected to one end of a current sampling resistor (R101) and is connected to the input of the output current feedback unit, and the other end of the current sampling resistor (R101) serves as the second output (DC-) of the power supply module; the second output (VS) of the output rectifying and filtering unit is connected to the input of the output current feedback unit, the first output (VC) of the output current feedback unit is connected to the input of the output voltage feedback unit, and the second output (VA) of the output current feedback unit serves as the third output (VA) of the power supply module. The present invention not only realizes the parallel current sharing function, but also makes the fluctuation of the output voltage within a controllable range.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a power supply module and a power supply system. Background Art

[0002] In the prior art, the power module with automatic current balancing function has its output voltage feedback unit and output current feedback unit connected to the feedback optocoupler at the same time. The disadvantage of this connection is that at any time, only one of the two feedback loops takes over the feedback optocoupler. When the output current of the output current feedback unit passes through the feedback optocoupler, the output voltage feedback unit has no current flowing to the feedback optocoupler. At this time, the output voltage is in an uncontrollable state; when the load is a non-constant voltage load (battery, etc.), it may cause the output voltage of the power module to fluctuate too much. Therefore, this circuit can only be applied to intelligent fields such as communications, electricity, servers with central monitors and industries with energy storage batteries, and cannot be applied to ordinary industrial fields.

[0003] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a power supply module and a power supply system to address the above-mentioned defects of the prior art, so that the output voltage thereof is controllable and reliable and is widely used in various industrial fields.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0006] A power module, comprising:

[0007] An input rectifying and filtering unit, a voltage conversion and isolation unit, an output rectifying and filtering unit, an output voltage feedback unit, a feedback isolation unit and a power control and drive unit are sequentially connected, and the output of the power control and drive unit is connected to the voltage conversion and isolation unit;

[0008] It also includes an output current feedback unit;

[0009] The first output of the output rectifying and filtering unit serves as the first output (DC+) of the power module, the second output (VS) of the output rectifying and filtering unit is connected to one end of a current sampling resistor (R101) and is connected to the input of the output current feedback unit, and the other end of the current sampling resistor (R101) serves as the second output (DC-) of the power module;

[0010] The second output (VS) of the output rectifying and filtering unit is connected to the input of the output current feedback unit, the first output (VC) of the output current feedback unit is connected to the input of the output voltage feedback unit, and the second output (VA) of the output current feedback unit serves as the third output (VA) of the power module.

[0011] Preferably, the output current feedback unit comprises a current signal sampling circuit and a comparison and regulation circuit;

[0012] The current signal sampling circuit is used to invert and amplify the value of the second output (VS) of the output rectification and filtering unit to obtain the second output (VA) of the output current feedback unit and the output (VB) of the current signal sampling circuit;

[0013] The comparison and regulation circuit is used to compare and proportionally regulate the second output (VA) of the output current feedback unit and the output (VB) of the current signal sampling circuit to obtain the first output (VC) of the output current feedback unit, and obtain a feedback voltage (VFB) by serially connecting a third resistor (R3), and the feedback voltage (VFB) is connected to the input of the output voltage feedback unit.

[0014] Preferably, the current signal sampling circuit includes a first operational amplifier (IC1A), and the comparison and regulation circuit includes a second operational amplifier (IC1B).

[0015] Preferably, the output current feedback unit further comprises a maximum current limiting circuit, which is used to limit the maximum value of the second output (VA) of the output current feedback unit;

[0016] The maximum current limiting circuit comprises a third operational amplifier (IC3) with a built-in reference voltage and two resistors, the second output (VA) of the output current feedback unit is connected to the ground through two series-connected eighteenth resistors (R18) and nineteenth resistors (R19), and the reference voltage end output by the third operational amplifier (IC3) with a built-in reference voltage is connected to the upper end of the nineteenth resistor (R19).

[0017] Preferably, the feedback isolation unit comprises an optocoupler, the output of the output voltage feedback unit is connected to the light-emitting side (OP1A) of the optocoupler, and the light-receiving side (OP1B) of the optocoupler is connected to the power control and driving unit.

[0018] Preferably, the output voltage feedback unit comprises an operational amplifier (IC2) with a second built-in reference voltage and three resistors, the first output (DC+) of the power module is connected to the ground through a sixth resistor (R6), a variable resistor (RV1) and a fifth resistor (R5), and the reference voltage output by the operational amplifier (IC2) with a second built-in reference voltage is connected to the upper end of the variable resistor (RV1).

[0019] Preferably, another output of the second operational amplifier (IC2) with a built-in reference voltage is used as the output of the output voltage feedback unit and is connected to the light-emitting side (OP1A) of the optocoupler.

[0020] Preferably, the output voltage feedback unit has three inputs, the first output (DC+) of the power module and the second output (DC-) of the power module serve as two inputs of the output voltage feedback unit; the feedback voltage (VFB) serves as the third input of the output voltage feedback unit and is connected to the upper end of the variable resistor (RV1) of the output voltage feedback unit.

[0021] The present invention also provides a power supply system, which includes a plurality of power supply modules as described above connected in parallel, wherein the first outputs (DC+) of all the power supply modules are connected together, the second outputs (DC-) of all the power supply modules are connected together, and the third outputs (VA) of all the power supply modules are connected together.

[0022] Preferably, the first output (DC+) of the power module and the second output (DC-) of the power module are used to provide direct current power to the load.

[0023] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0024] In the present application, the output end of the output current feedback unit is connected to the input end of the output voltage feedback unit, and the output end of the output voltage feedback unit is connected to the feedback isolation unit. Thus, when the power supply is working, since only the output voltage feedback unit directly acts on the isolation unit, the output current feedback unit indirectly controls the output voltage of the power supply by controlling the output voltage feedback unit, so that the output voltage of the power supply can be adjusted within a certain range. This not only realizes the parallel current sharing function, but also makes the fluctuation of the output voltage of the power supply within a controllable range. At the same time, it can be applied to high-frequency switching industrial power supplies with fixed wiring terminals, and is widely used. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the scheme of the present application, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a module schematic diagram of a preferred embodiment of the power module in the present invention.

[0027] Figure 2 It is a current signal sampling circuit diagram of an output current feedback unit in a preferred embodiment of the power module in the present invention.

[0028] Figure 3 It is a comparison adjustment circuit diagram of the output current feedback unit in a preferred embodiment of the power module in the present invention.

[0029] Figure 4 It is a maximum current limiting circuit diagram of the output current feedback unit in a preferred embodiment of the power module in the present invention.

[0030] Figure 5 4 is a circuit diagram of an output voltage feedback unit in a preferred embodiment of the power module of the present invention.

[0031] Figure 6 It is a module schematic diagram of a preferred embodiment of the power supply system in the present invention. DETAILED DESCRIPTION

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] like Figure 1As shown, a power module provided by a preferred embodiment of the present invention comprises: an input rectifying and filtering unit 10, a voltage conversion and isolation unit 20, an output rectifying and filtering unit 40, an output voltage feedback unit 50, a feedback isolation unit, a power control and drive unit 30 and an output current feedback unit 60 connected in sequence, wherein the output of the power control and drive unit 30 is connected to the voltage conversion and isolation unit 20; the first output of the output rectifying and filtering unit 40 serves as the first output (DC+) of the power module, the second output (VS) of the output rectifying and filtering unit 40 is connected to one end of a current sampling resistor (R101) and is connected to the input of the output current feedback unit 60, and the other end of the current sampling resistor (R101) serves as the second output (DC-) of the power module; the second output (VS) of the output rectifying and filtering unit 40 is connected to the input of the output current feedback unit 60, the first output (VC) of the output current feedback unit 60 is connected to the input of the output voltage feedback unit 50, and the second output (VA) of the output current feedback unit 60 serves as the third output (VA) of the power module.

[0035] The working principle of the power module is: when the output voltage of a certain power module detected is less than the maximum output voltage of the current sharing signal of all parallel power modules, the first output (VC) of the output current feedback unit 60 also decreases, and the first output (VC) is adjusted by the PID of the output voltage feedback unit 50, thereby controlling the feedback isolation unit and the power control and drive unit 30, and finally increasing the output voltage of the single power module and the output current, thereby achieving the purpose of adjusting the current of the single power module.

[0036] In a further preferred embodiment of the present invention, the output current feedback unit 60 includes a current signal sampling circuit (such as Figure 2 as shown) and the comparison adjustment circuit (as Figure 3 As shown); the current signal sampling circuit is used to invert and amplify the value of the second output (VS) of the output rectifying and filtering unit 40 to obtain the second output (VA) of the output current feedback unit 60 and the output (VB) of the current signal sampling circuit; the comparison and regulation circuit is used to compare and proportionally regulate the second output (VA) of the output current feedback unit 60 (which is the maximum value of the current sharing signal of all parallel power modules) and the output (VB) of the current signal sampling circuit (the output voltage of a single power module) to obtain the first output (VC) of the output current feedback unit, and obtain the feedback voltage (VFB) by serially connecting the third resistor (R3), and the feedback voltage (VFB) is connected to the input of the output voltage feedback unit.

[0037] When a current sampling resistor (R101) is connected between the first output (DC+) of the power module and the second output (VS) of the output rectifier filter unit 40, the output current generates a voltage drop on the resistor R101, and this voltage drop is proportional to the output current. Due to the power limitation of the current sampling resistor (R101), the voltage value between the second output (VS) and the ground (SGND) is a weak negative voltage. The weak negative voltage between the second output (VS) and the ground is proportionally amplified and reversed through the current signal sampling circuit. The output voltage of the current signal sampling circuit generates a "VA" signal after passing through the diode D11 and the resistor R13, and generates a "VB" signal after passing through the diode D12 and the resistor R14.

[0038] The output voltage "VB" signal of the single power module and the maximum output voltage "VA" signal of the parallel power modules are compared and PID-regulated by the second operational amplifier (IC1B), and the output signal (VC) of the second operational amplifier (IC1B) is connected to the VFB node of the output voltage feedback unit through the third resistor R3.

[0039] PID regulating is a basic regulation method of control systems in classical control theory. It is a linear regulation law with proportional, integral and differential effects.

[0040] Proportional regulation: It is to respond to the deviation of the system in proportion. Once the system has a deviation, the proportional regulation will immediately produce a regulating effect to reduce the deviation. A large proportional effect can speed up the regulation and reduce the error, but a too large proportion will reduce the stability of the system and even cause instability.

[0041] Integral regulation: It is to eliminate the steady-state error of the system and improve the degree of error-free. Because there is an error, the integral regulation is carried out until there is no error, the integral regulation stops, and the integral regulation outputs a constant value. The strength of the integral action depends on the integral time constant T. The smaller T is, the stronger the integral action is. On the contrary, the larger T is, the weaker the integral action is. Adding integral regulation can reduce the stability of the system and slow down the dynamic response. The integral action is often combined with the other two regulation rules to form a PI regulator or a PID regulator.

[0042] Differential regulation: The differential action reflects the rate of change of the system deviation signal, and is predictive. It can predict the trend of deviation change, so it can produce advanced control. Before the deviation is formed, it has been eliminated by the differential regulation. Therefore, the dynamic performance of the system can be improved. When the differential time is properly selected, overshoot can be reduced and the adjustment time can be reduced. The differential action has an amplifying effect on noise interference, so too strong differential regulation is not conducive to the system's anti-interference. In addition, the differential reflects the rate of change, and when the input does not change, the differential action output is zero. The differential action cannot be used alone, and needs to be combined with the other two regulation laws to form a PD or PID controller.

[0043] In a further preferred embodiment of the present invention, the output current feedback unit 60 further includes a maximum current limiting circuit (such as Figure 4 As shown), it is used to limit the maximum value of the second output (VA) of the output current feedback unit; the maximum current limiting circuit includes a third operational amplifier (IC3) with a built-in reference voltage and two resistors, the second output (VA) of the output current feedback unit is connected to the ground through two series-connected eighteenth resistors (R18) and nineteenth resistors (R19), and the reference voltage end output by the third operational amplifier (IC3) with a built-in reference voltage is connected to the upper end of the nineteenth resistor (R19).

[0044] like Figure 4 As shown, a maximum current limiting circuit is added between the second output (VA) of the output current feedback unit 60 and the ground. The circuit limits the maximum voltage value between the second output (VA) and the ground through an operational amplifier (IC3). When the voltage value between the second output (VA) and the ground is greater than a set value, the operational amplifier (IC3) limits its voltage value to the set value through the impedance between the second output (VA) and the ground. An example is as follows:

[0045] when Figure 4 The built-in reference voltage of the operational amplifier (IC3) in the power supply module is 2.5V, and the maximum value of the output current "I_OUT" of a single power module is calculated as follows:

[0046]

[0047]

[0048]

[0049] Because the voltage value between the second output (VA) and the ground is proportional to the output current of the power module, this limits the maximum output current of the power module, so that each power module in the parallel system of multiple power modules works below the safe power value.

[0050] The maximum current limiting circuit samples, adjusts and limits the maximum value of the VA voltage through a third operational amplifier (IC3) with a built-in reference voltage, thereby limiting the maximum value of the VS voltage. Since the VS voltage value is proportional to the output current of the power module, the maximum output current of the power module is ultimately limited.

[0051] In a further preferred embodiment of the present invention, Figure 1 As shown, the feedback isolation unit includes an optocoupler, the output of the output voltage feedback unit 50 is connected to the light-emitting side (OP1A) of the optocoupler, and the light-receiving side (OP1B) of the optocoupler is connected to the power control and driving unit 30 .

[0052] In a further preferred embodiment of the present invention, Figure 5 As shown, the output voltage feedback unit 50 includes a second operational amplifier (IC2) with a built-in reference voltage and three resistors. The first output (DC+) of the power module is connected to the ground through a sixth resistor (R6), a variable resistor (RV1) and a fifth resistor (R5). The reference voltage output by the second operational amplifier (IC2) with a built-in reference voltage is connected to the upper end of the variable resistor (RV1). The other output of the second operational amplifier (IC2) with a built-in reference voltage is used as the output (VD) of the output voltage feedback unit 50 and is connected to the light-emitting side (OP1A) of the optocoupler.

[0053] The output voltage feedback unit has three inputs, the first output (DC+) of the power module and the second output (DC-) of the power module serve as two inputs of the output voltage feedback unit; the feedback voltage (VFB) serves as the third input of the output voltage feedback unit and is connected to the upper end of the variable resistor (RV1) of the output voltage feedback unit.

[0054] The first output (VC) of the output current feedback unit 60 is connected to the input terminal (VFB) of the output voltage feedback unit 50 through the third resistor (R3), and the influence depth of the output current feedback unit 60 on the output voltage feedback unit 50 is controlled by adjusting the third resistor (R3). An example is given below:

[0055] like Figure 3 As shown in the figure, when "VCCS" = 12V, the maximum output voltage of the 7th pin of the second operational amplifier (IC1B) is 11.7V when not in parallel (working alone); Figure 5 As shown, the built-in reference voltage of the second built-in reference voltage operational amplifier (IC2) is 2.5V. According to the principle that the current flowing into the VFB node is always equal to the current flowing out of the VFB node, the calculation formula of the "DC+" voltage of the power module is:

[0056]

[0057] The preferred embodiment of the present invention also provides a power supply system, such as Figure 6 As shown, the power supply system includes a plurality of the power supply modules described above connected in parallel, the first outputs (DC+) of all the power supply modules are connected together, the second outputs (DC-) of all the power supply modules are connected together, and the third outputs (VA) of all the power supply modules are connected together, and the first output (DC+) of the power supply module and the second output (DC-) of the power supply module are used to provide DC power to the load.

[0058] When the first output (DC+), the second output (DC-), and the third output (VA) of multiple identical power modules are connected together, due to the effect of diode D11, after the multiple identical power modules are connected in parallel, the voltage value between the "VA" of one of the power modules and the ground becomes larger, then the "VA" of the power module is the maximum value of the "VA" output by the power system.

[0059] When multiple power modules are connected in parallel to form a power system, if the output voltage VB of other single power modules in the power system is less than the maximum output voltage VA in the power system, the voltage of the 7th pin of the second operational amplifier (IC1B) reaches the minimum value of 0.3V. At this time, the "DC+" of the other single power module will rise, and finally the output voltage VB and VA of the other single power module will be equal. The calculation formula of the "DC+" of the power module is as follows:

[0060]

[0061] The calculation formula for the maximum adjustable voltage of a single power module in this power system is as follows:

[0062]

[0063]

[0064] According to this formula, the maximum adjustable voltage of a single power module in the power system can be set by the sixth resistor R6 and the third resistor R3, so the output voltage is controllable, and the risk of power output voltage being out of control in the parallel current sharing circuit of the prior art will not occur.

[0065] When the total load is less than 1100W, 10 100W power modules are connected in parallel and tested at full load and half load. The test results show that the current imbalance is less than ±5%, which meets the use requirements. When the power system is tested for dynamic load and power on / off, the output voltage fluctuation is also less than ±5%, which meets the specification requirements.

[0066] The present invention does not need to be connected to a central controller, and does not need to be connected to an energy storage battery at the secondary DC voltage output terminal. It can be applied to a wider range of general industrial fields such as large-scale mechanical equipment, LED display, and self-service vending equipment.

[0067] In addition, the power module and power system provided by the present invention can be applied to high-frequency switching power supplies with any appearance and structural form, and can also be implemented in any printed circuit board layout connection method.

[0068] The components in the power module can be components of the same principle and performance in any package, and their series and parallel combinations.

[0069] In summary, the power supply module and power supply system provided by the present invention connect the output end of the output current feedback unit to the input end of the output voltage feedback unit, and the output end of the output voltage feedback unit to the feedback isolation unit. When the power supply is working, since only the output voltage feedback unit directly acts on the isolation unit, the output current feedback unit indirectly controls the output voltage of the power supply by controlling the output voltage feedback unit, so that the output voltage of the power supply can be adjusted within a certain range. This not only realizes the parallel current sharing function, but also makes the fluctuation of the power supply output voltage within a controllable range. At the same time, since a maximum current limiting circuit is added to the output current feedback unit, the maximum output current of the power supply module can be displayed. In addition, the power supply module can be used in high-frequency switching industrial power supplies with fixed wiring terminals, and is widely used.

[0070] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A power module, comprising: An input rectifying and filtering unit, a voltage conversion and isolation unit, an output rectifying and filtering unit, an output voltage feedback unit, a feedback isolation unit and a power control and drive unit are sequentially connected, and the output of the power control and drive unit is connected to the voltage conversion and isolation unit, characterized in that the power module also includes an output current feedback unit; The first output of the output rectifying and filtering unit serves as the first output (DC+) of the power module, the second output (VS) of the output rectifying and filtering unit is connected to one end of a current sampling resistor (R101) and is connected to the input of the output current feedback unit, and the other end of the current sampling resistor (R101) serves as the second output (DC-) of the power module; The second output (VS) of the output rectifying and filtering unit is connected to the input of the output current feedback unit, the first output (VC) of the output current feedback unit is connected to the input of the output voltage feedback unit, the second output (VA) of the output current feedback unit serves as the third output (VA) of the power module, and the output (VD) of the output voltage feedback unit (50) is connected to the feedback isolation unit; The output current feedback unit includes a current signal sampling circuit and a comparison and regulation circuit; The current signal sampling circuit is used to invert and amplify the value of the second output (VS) of the output rectification and filtering unit to obtain the second output (VA) of the output current feedback unit and the output (VB) of the current signal sampling circuit; The comparison and regulation circuit is used to compare and proportionally regulate the second output (VA) of the output current feedback unit and the output (VB) of the current signal sampling circuit to obtain the first output (VC) of the output current feedback unit, and obtain a feedback voltage (VFB) by connecting a third resistor (R3) in series, and the feedback voltage (VFB) is connected to the input of the output voltage feedback unit; the current signal sampling circuit includes a first operational amplifier (IC1A), and the comparison and regulation circuit includes a second operational amplifier (IC1B); The output current feedback unit further comprises a maximum current limiting circuit, which is used to limit the maximum value of the second output (VA) of the output current feedback unit; The maximum current limiting circuit comprises a third operational amplifier (IC3) with a built-in reference voltage and two resistors, the second output (VA) of the output current feedback unit is connected to the ground through two series-connected eighteenth resistors (R18) and nineteenth resistors (R19), and the reference voltage end output by the third operational amplifier (IC3) with a built-in reference voltage is connected to the upper end of the nineteenth resistor (R19).

2. The power module according to claim 1, characterized in that: The feedback isolation unit comprises an optocoupler, the output of the output voltage feedback unit is connected to the light-emitting side (OP1A) of the optocoupler, and the light-receiving side (OP1B) of the optocoupler is connected to the power control and driving unit.

3. The power module according to claim 2, characterized in that: The output voltage feedback unit includes a second operational amplifier (IC2) with a built-in reference voltage and three resistors. The first output (DC+) of the power module is connected to the ground through a sixth resistor (R6), a variable resistor (RV1) and a fifth resistor (R5). The reference voltage output by the second operational amplifier (IC2) with a built-in reference voltage is connected to the upper end of the variable resistor (RV1).

4. The power module according to claim 3, characterized in that: Another output of the second operational amplifier (IC2) with a built-in reference voltage is used as the output of the output voltage feedback unit and is connected to the light-emitting side (OP1A) of the optical coupler.

5. The power module according to claim 3, characterized in that: The output voltage feedback unit has three inputs, the first output (DC+) of the power module and the second output (DC-) of the power module serve as two inputs of the output voltage feedback unit; the feedback voltage (VFB) serves as the third input of the output voltage feedback unit and is connected to the upper end of the variable resistor (RV1) of the output voltage feedback unit.

6. A power supply system, characterized in that: The invention comprises a plurality of power modules as claimed in any one of claims 1 to 5 connected in parallel, wherein the first outputs (DC+) of all the power modules are connected together, the second outputs (DC-) of all the power modules are connected together, and the third outputs (VA) of all the power modules are connected together.

7. The power supply system according to claim 6, characterized in that: The first output (DC+) of the power module and the second output (DC-) of the power module are used to provide direct current power to the load.

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