TW201528672A - Power system and DC converter thereof - Google Patents

Abstract

The present invention discloses a power system and its DC converter. The DC converter is mainly composed of a non-isolated converter module and an isolated converter module. The non-isolated converter module is a redundant structure, which includes a first power conversion circuit, a second power conversion circuit and an energy storage element. The first and second non-isolated power conversion modules are connected to and share the energy storage element, and the energy storage element is connected to the input terminal of the isolated converter module; after the first and second power conversion circuits of the non-isolated converter module convert the DC power outputted by two batteries, the result is outputted to the isolated converter module, and then the isolated converter module supplies the DC power to a load. The above design may solve the problem of transformers taking too much space when using two sets of DC isolated converters to assemble a traditional power system.

Description

Power system and its DC converter

The invention relates to a power supply system and a DC converter thereof, in particular to a DC converter composed of a non-isolated conversion module as a front stage and an isolated conversion module as a rear stage, which is used for solving the conventional DC conversion. The problem that the transformer is composed of two or more sets of isolated converters occupies a volume space.

As shown in FIG. 7, a power supply system includes an AC/DC converter 80, a DC converter 70, and two battery packs 73 and 74. The AC/DC converter 80 has an AC power input terminal and a DC power output. The AC power input end is connected to the AC main power, the DC power output end is connected to the DC power input end of the DC converter 70, and the two battery packs 73 and 74 are respectively connected to the DC power input of the DC converter 70. As a backup, when the AC mains supply is abnormal, the DC converter 70 converts the power of the battery packs 73 and 74 into the required voltage, and continues to supply the load.

When the power supply system is used in the communication system, the DC converter 70 has a negative output voltage, and the basic structure of the DC converter 70 having the negative output voltage is as shown in FIG. 8 , and includes a first power conversion module 71 . a second power conversion module 72, the first power conversion module 71 and the second power conversion module 72 respectively have a positive power input terminal Vcom and a negative power input terminal RTN1, RTN2, the first and second power sources The positive power input terminals Vcom of the conversion modules 71, 72 are commonly connected to the positive power terminals of the two battery packs 73, 74, and the negative power input terminals RTN1, RTN2 are independently connected to the negative power terminals of the battery packs 73, 74, respectively. Furthermore, the first and second power conversion modules 71 and 72 respectively have a set of power output terminals and are connected in parallel.

The DC converter described above employs a redundant architecture that can each perform DC power conversion to collectively supply DC power to the load. When one of the battery packs 73, 74 is abnormal or any one of the battery packs 73, 74, the first power conversion module 71 or the second power conversion module 72 is abnormal, the normal first power conversion module 71 or the first The two power conversion modules 72 can still maintain the power supply to the load and achieve the effect of redundant power supply.

The first power conversion module 71 and the second power conversion module 72 of the DC converter are all composed of an isolated converter, and the isolated converter is provided with at least one transformer for a communication system or server that receives power supply. In terms of the system, how to reduce the size and reduce the space occupation has always been an important issue regardless of the power supply system itself or the power supply system used. However, the above-mentioned DC converter has two power conversion modules 71 composed of isolated converters. , 72 has a transformer, and the space-consuming transformer naturally becomes the biggest obstacle to reduce the volume.

As can be seen from the above, it is known that a DC converter having a redundant architecture in a power supply system has a power conversion module composed of two or more isolated converters, and the transformer takes up space and the DC converter cannot reduce the volume. The problem is that there are both DC converters to be further reviewed and to find a viable solution.

Therefore, the main object of the present invention is to provide a DC converter, which is mainly composed of a non-isolated pre-stage conversion module and an isolated post-stage conversion module, which can solve the problem that the conventional DC converter is separated by two or more groups. The converter constitutes the problem of the volume occupied by the transformer derived.

The main technical means for achieving the foregoing objective is that the DC converter includes: a non-isolated conversion module, which is a redundant architecture, and includes a first power conversion circuit, a second power conversion circuit, and a storage. The first component and the second power conversion circuit are connected to and share the energy storage component; and the isolation conversion module has a set of input terminals and a set of output terminals, wherein the input terminals are connected to the energy storage component;

The DC converter described above mainly converts the DC power output of the two battery packs to the isolated conversion module by the first and second power conversion circuits of the non-isolated conversion module, and then supplies the isolated conversion module. The DC power supply is applied to the load; since the first and second power conversion circuits in the non-isolated conversion module do not contain a transformer, the volume can be greatly reduced, and the isolated conversion module with the latter stage has only one transformer, so the phase Compared with the traditional DC converter, the volume has been greatly reduced, and the volume problem of the transformer occupied by the conventional DC converter using two sets of isolated converters is solved.

Another object of the present invention is to provide a power supply system capable of reducing the volume. To achieve the foregoing objective, the power supply system includes: an AC/DC converter having an AC power input end and a DC power output end, and an AC power input thereof. The end is used for connecting AC mains; the DC converter is composed of the aforementioned DC converter, and has a DC power input end and a power output end, and the DC power input end is connected to the DC power output end of the AC/DC converter. Connected; two battery packs, respectively, connected across the DC power input of the DC converter.

The above power supply system includes the aforementioned DC converter, thereby helping to reduce the size of the power supply system.

The basic architecture of a preferred embodiment of the DC converter of the present invention, as shown in FIG. 1, includes a non-isolated conversion module 10, an isolated conversion module 20, and a controller 30;

The non-isolated conversion module 10 is mainly composed of a first power conversion circuit 11 and a second power conversion circuit 12, and the first and second power conversion circuits 11 and 12 respectively have a positive power terminal Vcom and a negative power source. End RTN1, RTN2. In the embodiment, the DC converter of the present invention further includes a first EMI filter 41 and a second EMI filter 42. The first power conversion circuit 11 and the second power conversion circuit of the non-isolated conversion module 10 The first power supply terminal Vcom and the negative power supply terminal RTN1 and RTN2 are connected to the first battery pack 103 and the second battery pack 104 through the first EMI filter 41 and the second EMI filter 42 respectively. The positive terminals V+ of the two battery packs 103 and 104 are connected in common and are respectively connected to the positive power terminals Vcom of the first and second power conversion circuits 11 and 12. The negative terminals of the first and second battery groups 103 and 104 are respectively 1. The negative power terminals RTN1 and RTN2 of the second power conversion circuits 11, 12 are connected.

The controller 30 is connected to the first power conversion circuit 11 , the second power conversion circuit 12 and the isolated conversion module 20 of the non-isolated conversion module 10 to control the non-isolated conversion module 10 and the isolated conversion module. Group 20 power conversion work.

For the specific configuration of the non-isolated conversion module 10, please refer to FIG. 2. In this embodiment, the first and second power conversion circuits 11 and 12 of the non-isolated conversion module 10 respectively Is a buck converter; where:

The first power conversion circuit 11 includes a first diode D1, a first switch Q1, a first inductor L1, and an energy storage component. In this embodiment, the energy storage component is an output capacitor C, and the output is The capacitor C has a first end and a second end. The first end and the cathode of the first diode D1 are connected to the positive power terminal Vcom, and the second end is connected to one end of the first inductor L1. The first inductor L1 The other end is connected to the anode of the first diode D1 and the first switch Q1. In this embodiment, the first switch Q1 is a field effect transistor, and the source and the other end of the first inductor L1 are the first two. The anode of the pole D1 is connected, the drain of the first switch Q1 is connected to the negative power terminal RTN1, and the gate is connected and controlled by the controller 30.

The second power conversion circuit 12 includes a second diode D2, a second switch Q2, a second inductor L2, and an energy storage component. In this embodiment, the energy storage component is shared with the first power conversion circuit 11. The output capacitor C, the first end of the output capacitor C is connected to the cathode of the second diode D2 to the positive power terminal Vcom, the second terminal is connected to one end of the second inductor L2, and the second inductor L2 is The terminal is connected to the anode of the second diode D2 and the second switch Q2. The same as the first power conversion circuit 11 is: the second switch Q2 is a field effect transistor, and the other end of the source and the second inductor L2 The anode of the second diode D2 is connected, the drain of the second switch Q2 is connected to the negative power terminal RTN2, and the gate thereof is connected to the controller 30 and controlled by the controller 30.

The first end and the second end of the output capacitor C respectively constitute a positive power output terminal Vout and a negative power output terminal RTN of the non-isolated conversion module 10, and are connected to the set of input terminals of the isolated conversion module 20.

The first and second power conversion circuits 11 and 12 of the non-isolated conversion module 10 respectively convert the power supplies of the first and second battery packs 103 and 104 into a set voltage DC power supply under the alternate driving of the controller 30. The DC power source that is transmitted to the isolated conversion module 20 and converted to another set voltage is supplied to the load. The working principle of the non-isolated conversion module 10 is as follows:

As for the first power conversion circuit 11, when the first switch Q1 is turned on, current flows through the output capacitor C and the first inductor L1, at which time the voltage of the output capacitor C rises, and the first inductor L1 performs energy storage. The first switch Q1 is turned off, and the energy stored on the first inductor L1 charges the output capacitor C through the first diode D1. On the other hand, when the second switch Q2 of the second power conversion circuit 12 is turned on, current flows through the output capacitor C and the second inductor L2, at which time the voltage of the output capacitor C rises and is stored by the second inductor L2. When the second switch Q2 is turned off, the energy stored in the second inductor L2 charges the output capacitor C through the second diode D2. The alternate driving is performed to output a DC power to the isolated conversion module 20. The DC power output from the isolated conversion module 20 can be a positive voltage or a negative voltage.

Since the first and second power conversion circuits 11 and 12 of the non-isolated conversion module 10 do not use a transformer, the isolation conversion module 20 in the subsequent stage also has only one transformer, so that the space occupied by the transformer can be effectively solved. The volume problem.

For a further preferred embodiment of the non-isolated conversion module 10, referring to FIG. 3, the first and second power conversion circuits 11', 12' are formed by a boost converter, wherein:

The first power conversion circuit 11' includes a first diode D1, a first switch Q1, a first inductor L1, and an output capacitor C. The output capacitor C has a first end and a second end. The first end and the first switch Q1 have a source connected to the positive power terminal Vcom, the second end of which is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the drain of the first switch Q1. The drain is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to the negative power terminal RTN1, and the gate of the first switch Q1 is connected to the controller 30.

The second power conversion circuit 12' includes a second diode D2, a second switch Q2, a second inductor L1, and an output capacitor C. The output capacitor C is shared with the first power conversion circuit 12'. The first terminal and the second switch Q2 have their sources connected to the positive power supply terminal Vcom, the first end of which is connected to the anode of the second diode D2, the cathode of the second diode D2 and the second terminal of the second switch Q2. The drain of the second switch Q2 is connected to one end of the second inductor L2, the other end of the second inductor L2 is connected to the negative power supply terminal RTN2, and the gate of the second switch Q2 is connected to the controller 30.

The difference between the above embodiment and the previous embodiment is that the first and second power conversion circuits 11', 12' of the non-isolated conversion module 10 perform boost conversion on the power supplies of the first and second battery packs 103, 104. Then, the isolated conversion module 20 converts to a DC power source of another set voltage, which may still be a positive voltage or a negative voltage. The working principle of the non-isolated conversion module 10 described above is as follows:

Regarding the operation of the first power conversion circuit 11', when the first switch Q1 is turned on, the first inductor L1 is stored. The first switch Q1 is turned off, and the energy stored on the first inductor L1 discharges the output capacitor C, and the current flows through the output capacitor C and the first diode D1.

The second power conversion circuit 12' operates in such a manner that when the second switch Q2 is turned on, the second inductor L2 is stored. The second switch Q2 is turned off, and the energy stored in the second inductor L2 discharges the output capacitor C, and the current flows through the output capacitor C and the second diode D2. The alternate driving is performed to output a DC power supply to the isolated conversion module 20. Similarly, the DC power output of the isolated conversion module 20 may be a positive voltage or a negative voltage.

For another preferred embodiment of the DC converter of the present invention, referring to FIG. 4, the first and second power conversion circuits 11, 12 of the non-isolated conversion module 10 are divided on their negative power terminals RTN1 and RTN2. A current detecting element 51, 52 is provided, which is connected to the controller 30, respectively, so that the input current of the non-isolated conversion module 10 is sensed by the controller 30. The current detecting elements 51, 52 may be Hall elements, resistors or current comparators (CT).

Since the positive power terminals Vcom of the first and second power conversion circuits 11 and 12 are connected in common, the first and second power conversion circuits 11 and 12 are respectively provided with current detecting elements 51 and 52 at their negative power terminals RTN1 and RTN2. The controller 30 accurately determines the input currents of the first and second power conversion circuits 11, 12, respectively, and controls the first and second power conversion circuits 11, 12 by the controller 30 to perform current sharing, when the non-isolated conversion mode The output current of the group 10 is Iout. When the output currents of the first and second power conversion circuits 11 and 12 are I1 and I2, respectively, Iout=I1+I2, and I1=I2. As for the technique for realizing voltage equalization and current sharing by the controller 30, a master-slave method or an active current sharing method can be used. On the other hand, the foregoing design can also conveniently determine the specifications of the front-stage fuseless switches 105, 106 of the non-isolated conversion module 10 (refer to FIG. 1), and the fuseless switch determined by the manners can be reduced. Specifications can reduce costs.

The foregoing embodiment is described by taking the first and second power conversion circuits 11 and 12 of the step-down type as an example. It is understood by those skilled in the art that it can also be applied to the first and second types of the boost type. Power conversion circuits 11', 12' (as shown in Figure 5).

It can be seen from the above that the DC converter of the present invention is mainly composed of a non-isolated conversion module and an isolated conversion module, and the first and second power conversion circuits in the non-isolated conversion module do not have a transformer. Compared with the isolated conversion module as the latter stage, there is only one transformer, so the conventional DC converter with at least two transformers can greatly reduce the space and solve the volume problem.

Please refer to FIG. 6 , which is a power system 100 including the foregoing DC converter. The power system 100 includes: an AC/DC converter 101 having an AC power input terminal and a DC power output terminal, and an AC power input thereof. The end is used to connect the AC mains; the DC converter 102 can be respectively composed of the DC converters of the foregoing embodiments, the DC converter 102 has a DC power input end and a power output end, and the DC power input end is The first and second power conversion circuits are formed by positive and negative power terminals, and are connected to the DC power output end of the AC/DC converter 101; the two battery groups are respectively connected to the DC power input end of the DC converter 102. More specifically, the two battery packs include a first battery pack 103 and a second battery pack 104. The positive terminals of the first and second battery packs 103 and 104 are common to the first and second converters 102. The positive power terminal of the second power conversion circuit is connected, the negative terminal of the first battery pack 103 is connected to the negative power terminal of the first power conversion circuit of the DC converter 102, and the negative terminal of the second battery pack 104 is Connected to the negative power supply terminal of the second power conversion circuit in the DC converter 102.

The foregoing power supply system adopts the DC converter of the above embodiments, and the DC converter is designed to reduce the use of the transformer, which helps to reduce the volume, and the power supply system uses the DC converter, which also contributes to the volume of the system. The reduction.

10‧‧‧ Non-isolated conversion module
11,11'‧‧‧First power conversion circuit
12, 12'‧‧‧Second power conversion circuit
20‧‧‧Isolated conversion module
30‧‧‧ Controller
41‧‧‧First EMI filter
42‧‧‧Second EMI filter
51, 52‧‧‧ Current sensing components
100‧‧‧Power system
101‧‧‧ AC-DC converter
102‧‧‧DC Converter
103‧‧‧First battery pack
104‧‧‧Second battery pack
105, 106‧‧‧ no fuse switch
70‧‧‧DC Converter
71‧‧‧First power conversion module
72‧‧‧Second power conversion module
73, 74‧‧‧ battery pack

1 is a system block diagram of a preferred embodiment of a DC converter of the present invention. 2 is a circuit diagram of a preferred embodiment of a non-isolated conversion module of the present invention. 3 is a circuit diagram of still another preferred embodiment of the non-isolated conversion module of the present invention. 4 is a circuit diagram of still another preferred embodiment of the non-isolated conversion module of the present invention. FIG. 5 is a circuit diagram of another preferred embodiment of the non-isolated conversion module of the present invention. Figure 6 is a block diagram of a power supply system of the present invention. Figure 7 is a block diagram of a known power supply system. Figure 8 shows a system block diagram of a known DC converter.

10‧‧‧ Non-isolated conversion module

11‧‧‧First power conversion circuit

12‧‧‧Second power conversion circuit

Claims (10)

A DC converter includes: a non-isolated conversion module, which is a redundant architecture, including a first power conversion circuit, a second power conversion circuit, and an energy storage component, the first and second power sources The conversion circuit is connected and shares the energy storage component; an isolated conversion module has a set of inputs and a set of outputs, the set of inputs being connected to the energy storage component. The DC converter according to claim 1, wherein the first and second power conversion circuits of the non-isolated conversion module are respectively a buck converter, and each has a positive power terminal and a negative power terminal, and the storage device The energy component is an output capacitor, the output capacitor has a first end and a second end, wherein: the first power conversion circuit includes a first diode, a first switch, and a first inductor; the output capacitor The first end and the cathode of the first diode are connected to the positive power terminal of the first power conversion loop, and the second end is connected to one end of the first inductor, the other end of the first inductor and the anode of the first diode a first switch is connected, the first switch is a field effect transistor, and the source is connected to the other end of the first inductor and the anode of the first diode, and the drain of the first switch is connected to the first power conversion circuit. a negative power supply terminal, the gate is connected to a controller; the second power conversion circuit includes a second diode, a second switch, and a second inductor, and the first end of the output capacitor is the second diode The cathode of the body is connected in common to the positive of the second power conversion circuit a power terminal, the second end is connected to one end of the second inductor, the other end of the second inductor is connected to the anode of the second diode, and the second switch; the second switch is a field effect transistor, the source and the second The other end of the inductor, the anode of the second diode, the drain of the second switch is connected to the negative power terminal of the second power conversion loop, and the gate is connected to the controller and controlled by the controller; the output capacitor The first end and the second end respectively constitute a positive power output end and a negative power output end of the non-isolated conversion module, and are connected to the set input end of the isolated conversion module. The DC converter according to claim 1, wherein the first and second power conversion circuits of the non-isolated conversion module are respectively a boost converter, and each has a positive power terminal and a negative power terminal, and the storage The energy component is an output capacitor having a first end and a second end. The first power conversion circuit includes a first diode, a first switch and a first inductor. The output capacitor The first end and the first switch have a source connected to the positive power terminal of the first power conversion circuit, the second end of which is connected to the anode of the first diode, the cathode of the first diode and the first switch a pole connection, the drain of which is connected to one end of the first inductor, the other end of the first inductor is connected to the negative power terminal of the first power conversion loop, and the gate of the first switch is connected to a controller; the second power source The switching circuit includes a second diode, a second switch, and a second inductor. The first end of the output capacitor and the source of the second switch are connected to the positive power terminal of the second power conversion circuit, and the second end thereof Connected to the anode of the second diode, the second diode The cathode is connected to the drain of the second switch, the drain of the second switch is connected to one end of the second inductor, the other end of the second inductor is connected to the negative power terminal of the second power conversion loop, and the gate of the second switch The pole is connected to the controller; the first end and the second end of the output capacitor respectively constitute a positive power output end and a negative power output end of the non-isolated conversion module, and are connected to the input end of the isolated conversion module . The DC converter of claim 2 or 3, wherein the first and second power conversion circuits of the non-isolated conversion module are respectively provided with a current detecting component on the negative power terminal thereof, and the two current detecting components are respectively connected to the controller. . The DC converter according to claim 4, wherein the first power conversion circuit of the non-isolated conversion module, the positive power supply terminal and the negative power supply terminal of the second power conversion circuit are respectively connected to a first EMI filter and a second EMI filter. A DC converter as claimed in claim 4, wherein the current detecting element is a Hall element. The DC converter of claim 4, wherein the current detecting component is a resistor. The DC converter of claim 4, wherein the current detecting component is a current comparator. A power supply system comprising: an AC-DC converter having an AC power input end and a DC power output end, wherein an AC power input end is used to connect AC mains; a DC-converter is provided in claims 1 to 8 The DC converter of any one of the preceding claims, comprising: a DC power input end and a power output end, wherein the DC power input end is connected to the DC power output end of the AC/DC converter; the two battery packs are respectively connected On the DC power input of the DC converter. The power supply system of claim 9, wherein the first and second power conversion circuits of the non-isolated conversion module respectively have a positive power terminal and a negative power terminal, and the two battery packs comprise a first battery pack and a second battery. a battery pack, the positive ends of the first and second battery packs are connected in common to the positive power terminals of the first and second power conversion circuits in the DC converter, and the negative terminal of the first battery pack and the first power supply in the DC converter The negative power terminal of the conversion circuit is connected, and the negative terminal of the second battery pack is connected to the negative power terminal of the second power conversion circuit of the DC converter.