TW201436409A - Power parallel-connection system using current-limiting control - Google Patents

Abstract

The present invention relates to a power parallel-connection system using current-limiting control, primarily performs the output current distribution for multiple parallel power supply module so that each of the power modules provides power to load according to the distributive output current, while controlling the output voltage of the load; thereby only a portion of the power supply module supply power to the load under light-loadfor improving system efficiency; and power supply modules with the same voltage but different current may be implemented by using the above techniques . There is no limitation for number of power source module may be connected in parallel.

Description

Power supply parallel system with current limiting control

The invention relates to a power supply parallel system using current limiting control, in particular to an output current limiting control of a power module in a power parallel system to improve system efficiency and support parallel connection of power modules of the same voltage and different currents. Related technology.

In order to ensure the stability and reliability of the power supply system, most power supply systems modularize the power supply and connect the power modules of the same specification series in parallel to improve the output capability. There are two main types of parallel technology, one is the Active Current-Sharing Method, and the other is the Droop Method. The active current sharing method includes the average current method (Average current). Method), Dedicated Master Method and Automatic Master Method. The above two types of parallel technology are aimed at achieving current sharing.

However, as mentioned above, the parallel connection of multiple power modules is mainly to improve the output capability, while the voltage drop method can achieve the purpose of current sharing, but the output voltage must be sacrificed due to the reduced output voltage. The purpose of the output capability is opposite. Moreover, if the power modules reach a current sharing, the load must be working regardless of whether it is light or heavy, and each power module in the parallel system must work, and each power module outputs the same The current, therefore, under light load conditions, the system operating efficiency is significantly lower.

Furthermore, for the purpose of current sharing, it means that all power modules connected in parallel must have the same voltage and the same current. If the user has the same voltage but different current power modules, under the premise of achieving current sharing, different The current power module cannot be added to the parallel system, creating a waste of available resources.

It can be seen from the above that the parallel system is powered by multiple power modules connected in parallel, mainly to improve the output capability. However, although the voltage drop method can achieve the current sharing purpose, the output capability is reduced, so how to ensure the stability of the system does not affect the output capability. It is still subject to further review and seeking a viable solution.

Therefore, the main purpose of the present invention is to provide a power supply parallel system using current limiting control, which mainly performs output current distribution on each power module in a power parallel system, so that each power module supplies power according to the distributed output current, and according to the load. The status determines the number of power modules that are powered, to improve system efficiency. Since the output currents are distributed to the respective power modules, the power modules can be different currents, and the power modules that support the same voltage but different currents are connected in parallel, and the number of power modules connected in parallel is not limited.

A main technical means for achieving the foregoing objective is that the power supply parallel system adopting the current limiting control includes: a plurality of servant modules, each of the servant modules respectively having a converter and a current limiting control unit, the converter having a The output terminal is connected to an output bus; the current limiting control unit is configured to have a maximum output current, and is connected to the output bus to obtain a load current, and accordingly generates a current limiting command The output current is fixed, and the output current is limited by the converter to the output bus; a main module is connected in parallel with the foregoing servant modules, and is connected to the output bus to output voltage according to the load voltage fed back by the output bus. The constant voltage control is adopted; the power parallel system adopting the current limiting control mainly distributes the load on the output bus by the main and the servant components, but not the average sharing, but the servant module and the main module according to the current limiting control unit. The set maximum output current and load current are sequentially loaded onto the output bus, that is, each servant module and main module sequentially load the output current to the output bus with the maximum output current until the load current is satisfied. Under this condition, the number of power modules loaded to the output bus depends on the light and heavy load conditions of the load. If it is in the heavy load state, the number of power modules added in parallel is too large. If it is in the light load state, it is added in parallel. The number of power modules can be relatively reduced, that is, the power modules need not be operated, thereby improving operational efficiency. According to the current limiting control technology of the foregoing system, a power module capable of allowing different currents (capacity) can be added to the parallel system to fully utilize resources and improve system integration flexibility.

Another main technique for achieving the foregoing objective is that the power supply parallel system using the current limiting control includes: a main module including a converter, a current limiting control unit and a voltage controller, the converter having an output end And connected in common to an output bus; the current limiting control unit has an output end and an output current control end, the output end of which is connected to the converter; the voltage controller has a control signal output end, and a current limiting control unit Output current control terminal connection; a plurality of servant modules each having a converter and a current limiting control unit, the converter having an output and being commonly connected to an output bus; the current limiting control unit having an output and a The output current control end is connected to the converter, and the output current control end is connected to the output end of the current limiting control unit of the adjacent servant module or the main module through an arithmetic unit; the foregoing adopting The power supply parallel system of the current limiting control still distributes the load on the bus by the main and servant components. The distribution mode is controlled by the main module itself and the output current of each servant module, and is sequentially loaded onto the output bus. In this case, the number of power modules loaded to the output bus can be determined by the load condition. Since the output current of the current limiting power module is controlled by the main module, it is possible to allow power modules of different currents (capacity) to be added to the parallel system to fully utilize resources and improve system integration flexibility.

10A, 10B, 10C‧‧‧ servant module

10D‧‧‧ main module

11‧‧‧ converter

12‧‧‧ Current limiting control unit

121, 121A~121D‧‧‧ Current Limit Command Generator

122,122A~122D‧‧‧ Current controller

13‧‧‧Voltage controller

14A~14C‧‧‧Operator

1 is a block diagram of a system architecture of the present invention.

2 is a block diagram of a system in accordance with a preferred embodiment of the present invention.

3 is a block diagram of a system in accordance with still another preferred embodiment of the present invention.

The technical means adopted by the present invention for achieving the intended purpose of the invention are further described below in conjunction with the drawings and preferred embodiments of the invention.

For a basic architecture and working principle of a system according to a preferred embodiment of the present invention, please refer to FIG. 1 , which is mainly to enable a plurality of power modules 10A, 10B, 10C, and 10D to be connected to an output bus L by their outputs. And connected through the output bus L and the load (the number of power modules in the figure is only shown Just then).

The working principle of the present invention is that each power module 10A, 10B, 10C, 10D determines whether the output current I _O1 is loaded and loaded according to a set maximum output current I _OM and a load current I _L on the output bus L. , I _O2 , I _O3 , I _O4 , for example, when the load current is 10 amps, if the maximum output current I _{OM of} each power module 10A, 10B, 10C, 10D is set to 4 amps respectively, then under full load, The output currents I _O1 and I _{O2 of the} two power modules 10A and 10B are the maximum output current I _OM , and the output current I _{O3 of the} other power module 10C only needs 2 amps, and the output current I _{O4 of the} last power module 10D Then it is 0. In the light load state, when the load current is 4 amps, only one power module 10A needs to be loaded onto the output bus L with the maximum output current, while the output currents I _O2 , I of the other power modules 10B, 10C, and 10D are _O3 and I _O4 are both 0.

For the specific configuration of each of the power modules 10A, 10B, 10C, and 10D, please refer to FIG. 2: the power modules 10A, 10B, and 10C have the same basic structure, and are respectively used as a servant module and another power source. The module 10C includes a voltage controller 13 in addition to the same basic structure as the servant modules 10A, 10B, and 10C. The structure of the servant modules 10A, 10B, and 10C is described by one of the servant modules 10A. The structure comprises: a converter 11 having an output end and a control end, the output end of which is connected with the output bus L; a current limiting control unit 12 having an output end, a local current input terminal io1 and a bus The current input terminal i _L1 has an output terminal connected to the control terminal of the converter 11 and a local current input terminal io1 connected to the output terminal of the converter 11 to obtain its own output current; and its bus current input terminal i _L1 is The output bus L is connected; the current limiting control unit 12 is configured to have a maximum output current I _OM , and feedback the input load current according to the bus current input terminal i _L1 to generate a current limiting command, so that the converter 11 controls its output current Io1.

In this embodiment, the current limiting control unit 12 includes a current limiting command generator 121 and a current controller 122. The input terminal of the current limiting command generator 121 constitutes the bus current input terminal i _L1 , and outputs The bus L is connected to obtain the feedback load current, and accordingly generates a current limiting command, which is sent to the current controller 122, and the current controller 122 controls the output current Io1 of the converter 11.

In addition to the converter 11 and the current limiting control unit 12, the main module 10D further includes a voltage controller 13 having an input terminal, an output terminal, and a voltage command input terminal. The terminal is connected to the output bus L to feedback the output voltage, and the output terminal is connected to the current limiting command generator 121 of the current limiting control unit 12, the voltage controller 13 is based on a voltage command input voltage command and a self-output bus L. The feedback output voltage is generated to generate a control signal and sent to the current limit command generator 121 to perform voltage control on the load.

Each of the above-mentioned servant modules 10A, 10B, 10C and the main module 10D will control its output current piece by piece. The following is an example: please refer to FIG. 1 and FIG. 2, when the load current I _L is 10 When the ampere, the servant modules 10A, 10B, 10C and the main module 10D are respectively input to the output bus L with the maximum output current, and the load current I _L1 obtained by the first servant module 10A from the output bus L is 10 amps, and Maintaining the maximum output current; the load current I _L2 obtained by the second slave module 10B from the output bus L is 6 amps (I _L2 = I _{L1 -} I _O1 ), so the maximum output current is also maintained; the third mode The load current I _L3 obtained by the group 10C from the output bus L feedback is 2 amps (I _L3 = I _{L2 -} I _{O 2} ), so the third power supply module 10C will adjust its output current I _O3 to 2 amps. Since the output current of the first three servant modules 10A, 10B, and 10C input to the output bus L satisfies the demand of the load current I _L , the load current I _L4 obtained by the main module 10D from the output bus L is 0, so The output current I _O4 is also zero.

The current limit control (CC) is performed by each of the slave modules 10A, 10B, and 10C and the main module 10D. In order to ensure stable power supply, the main module 10D performs constant voltage control (CV) on the output voltage of the parallel system. Therefore, the servant modules 10A, 10B, and 10C are current limiting power modules, and the main module 10D is a voltage limiting power module.

Referring to FIG. 3, the basic architecture of the present invention is substantially the same as that of the previous embodiment, except that the output current of each of the servant modules 10A, 10B, and 10C is not based on itself. The feedback current is determined by the feedback, but is directly or indirectly controlled by the main module 10D. The specific configuration is as follows: the current limiting command generators 121A-121C of the servant modules 10A, 10B, and 10C are not connected to the output bus L, but are respectively transmitted through an arithmetic unit 14A-14C and the adjacent servant module 10B. 10C, the current limiting command generator 121 of the main module 10D is connected; the current limiting command generators 121A-121D of the servant modules 10A, 10B, 10C and the main module 10D respectively have an output current control terminal ioA~ioD, The output current control terminal ioD of the current limiting command generator 121D of the main module 10D is connected to the control signal output terminal of the voltage controller 13, The current limiting command output terminal and the output current control terminal ioD of the stream command generator 121D are respectively connected to the current controller 122D and the voltage controller 13, and are respectively connected to the arithmetic unit 14C of an adjacent servant module 10C.

Each of the computing units 14A-14C has an output terminal and two parameter terminals, and the output terminals thereof are connected to the output current control terminals ioA to ioC of the current limiting command generators 121A to 121C of the servant modules 10A, 10B, and 10C, respectively. The parameter terminals are respectively connected to the current limit command output terminals of the current limit command generators 121B, 121C, and 121D of the adjacent servant modules 10B and 10C or the main module 10D, and the output current control terminals ioB to ioD.

That is, the output currents Io1, Io2, and Io3 of the respective servant modules 10A, 10B, and 10C are respectively controlled by the adjacent servant modules 10B, 10C or the current limiting command generators 121B, 121C, 121D of the main module 10D.

The specific working mode is as follows: when the current limiting command generator 121D of the main module 10D obtains the load current demand of 10 amps from the voltage controller 13, the current limiting command generator 121D will send the current limiting current limit current. A command (for example, 4 amps) is applied to the current controller 122D to cause the converter 11D to output a maximum current of 4 amps. Since the load current demand is 10 amps, the current limiting command generator 121D has a current limiting command of 4 amps, which is operated by the arithmetic unit 14C. The difference, the load current demand of the current limiting command generator 121C provided to the adjacent servant module 10C is 6 amps; at this time, the current limiting command generator 121C still sends the current limiting command of the maximum output current to the current controller. 122C, the converter 11C outputs a maximum current of 4 amps, and thus, the current on the output bus L is 8 amps. The main module 10D sends a load current requirement of 6 amps to the servant module 10C, and the current limiting command generator 121C has a current limiting command of 4 amps, and the difference is calculated by the arithmetic unit 14B to provide another The current limit command generator 121B of the adjacent servant module 10B has a load current requirement of 2 amps. At this time, the current limit command generator 121B of the servant module 10B only needs to send a current limit command of 2 amps to load the converter 11B. Ampere outputs current to the output bus L. At this point, the current on the output bus L has reached 10 amps, and the load current requirement of the servant module 10B to the adjacent servant module 10A will be 0, that is, the current limiting command generator 121A of the servant module 10A sends the converter to the converter. The current limit command of 11A is 0, so there is no need to load current onto the output bus L.

It can be seen from the above that the power parallel system of the present invention mainly distributes the load on the output bus by each current limiting power mode component, but not the average sharing, but the maximum output set by each current limiting power module according to its current limiting control unit. The current and load current magnitude or control of the main module is loaded onto the output bus. Under this condition, the number of current limiting power modules loaded to the output bus may depend on the light and heavy load conditions of the load. If it is in the heavy load state, the number of parallel current limiting power supply modules is increased, and if it is in a light load state, The number of parallel current limiting power supply modules can be relatively reduced, that is, the current limiting power supply modules do not necessarily need to be operated, thereby improving the operating efficiency.

Regardless of whether the maximum output current is set or controlled by the main module, the current limiting control technology of the present invention according to the foregoing system can allow a power module of the same voltage and different current (capacity) to be added to the parallel system, thereby improving the system. The flexibility of integration and the full use of resources.

Furthermore, each of the foregoing power modules may be a DC power supply or an AC power supply. Therefore, it can be applied to a parallel system of DC power supply or a parallel system of AC power.

Number and number of servant modules in the above embodiments and figures It is not intended to limit the amount of actual use for convenience of explanation and ease of understanding.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention. A person skilled in the art can make some modifications or modifications to equivalent embodiments by using the above-disclosed technical contents without departing from the technical scope of the present invention. It is still within the scope of the technical solution of the present invention to make any simple modifications, equivalent changes and modifications to the above embodiments.

10A, 10B, 10C‧‧‧ servant module

10D‧‧‧ main module

11‧‧‧ converter

12‧‧‧ Current limiting control unit

121‧‧‧ Current Limit Command Generator

122‧‧‧ Current controller

Claims (11)

A power parallel system using current limiting control includes: a plurality of servant modules, each servant module having a converter and a current limiting control unit, the converter having an output terminal and being commonly connected to an output bus The current limiting control unit is configured to have a maximum output current, and is connected to the output bus to obtain a load current, and accordingly generates a current limiting command to limit the output current, and the converter loads the defined output current onto the output bus; A main module is connected in parallel with the foregoing servant modules and connected to the output bus to control the output voltage according to the load voltage fed back by the output bus. The power supply parallel system adopting current limiting control as claimed in claim 1, the main module has a converter and a current limiting control unit, the converter has an output end and is connected to the output bus; the current limiting control unit is provided with a The maximum output current is coupled to the output bus to obtain the load current, and a current limit command is generated to define the output current, and the converter outputs the defined output current to the output bus. The power supply parallel system adopting current limiting control as described in claim 2, the main and slave modules are DC power supplies. The power supply parallel system adopting current limiting control as described in claim 2, the main and servant modules are AC power supplies. The power supply parallel system using current limiting control according to any one of claims 1 to 4, wherein the current limiting control unit of the main and servant module comprises a current limiting command generator and a current controller, and the current limiting command is generated. The input of the device is connected to the output bus to obtain the feedback load current, and the current limiting command generator A current limiting command is generated and sent to the current controller, and the current controller controls the output current of the converter. The power supply parallel system adopting the current limiting control as described in claim 5, the voltage controller of the main module has an input end, an output end and a voltage command input end, and the input end is connected with the output bus, and the output end is limited. The current limiting command generator of the flow control unit is connected. A power supply parallel system using current limiting control, comprising: a main module comprising a converter, a current limiting control unit and a voltage controller, the converter having an output and being commonly connected to an output bus; The current limiting control unit has an output end and an output current control end, the output end of which is connected to the converter; the voltage controller has a control signal output end connected to the output current control end of the current limiting control unit; Each servant module has a converter and a current limiting control unit, the converter has an output terminal and is commonly connected to an output bus; the current limiting control unit has an output terminal and an output current control terminal The output end is connected to the converter, and the output current control end is connected to the output end of the current limiting control unit of the adjacent servant module or the main module through an arithmetic unit and the output current control end. The power limiting parallel system of the current limiting control is used in the seventh embodiment, and the current limiting control units of the servant and main modules 10D, 10A, 10B, and 10C respectively have a current controller 122A-122D and a current limiting command generator 121A. ~121D, the current controllers 122A-122D are respectively connected to the converters 122A-122D of the servant, main modules 10A, 10B, 10C, 10D; the current limiting commands of the servant, main modules 10A, 10B, 10C, 10D are generated The switches 121A-121D respectively have an output current control terminal ioA~ioD, the main The output current control terminal ioD of the current limiting command generator 121D of the module 10D is connected to the control signal output terminal of the voltage controller, and the current limiting command output terminal of the current limiting command generator 121D, the output current control terminal ioD and the current controller respectively 122D, voltage controller connection; each of the computing units 14A~14C has an output terminal and two parameter terminals, and the output terminal and the output current control terminal ioA of the current limiting command generators 121A-121C of the servant modules 10A, 10B, 10C The ~ioC connection is connected to the current limit command output of the current limit command generators 121B, 121C, 121D of the adjacent servant modules 10B, 10C or the main module 10D, and the output current control terminals ioB to ioD. The power supply parallel system adopting current limiting control as described in claim 8 is a DC power supply. The power supply parallel system using current limiting control as described in claim 8 is an AC power supply. The power supply parallel system using current limiting control according to any one of claims 8 to 10, wherein the main module simultaneously performs constant voltage control on the output voltage.