KR100935034B1 - Switching mode power supply of controlling multiple output and controlling method thereof - Google Patents

Abstract

PURPOSE: A switching power device and a control method thereof are provided to reduce a ripple noise and a switching noise by performing a PWM(Pulse Width Modulation) control through channel control signals having the same phase difference. CONSTITUTION: A switching power device includes an input part(110), an output part(120), and a control part(130). The input part supplies a DC input power to a plurality of channels(CH1~CHn). The output part converts the DC input power received through the channels into a DC output power(Vout1~Voutn). The control part generates channel control signals based on a target output value and an output value of the DC output power, and performs a PWM control.

Description

Switching power supply controlling a plurality of outputs and a control method thereof {Switching Mode Power Supply of Controlling Multiple Output and Controlling Method}

The present invention relates to a switching power supply for controlling a plurality of outputs and a control method thereof, and more particularly, a target output value in which a DC input is set by a control signal for each channel generated to have the same phase difference with each other according to the number of channels used. A switching power supply for converting to a direct current output having a and a control method thereof.

In general, Switching Mode Power Supply (SMPS) refers to a switching power supply, by switching the DC power voltage applied to the primary winding of the transformer so that induced electromotive force according to the winding ratio is induced in the secondary winding of the transformer, The power supply device generates a DC output voltage having a predetermined magnitude by rectifying induced electromotive force induced in the secondary winding through the rectifying unit.

Such SMPSs are used in power supplies in most electronic products today. However, as electronic products become smaller and more diverse, there is an increasing demand for SMPS that supports a variety of outputs, consumes less power, and has a smaller size.

The problem to be solved by the present invention is to convert a plurality of outputs by converting the DC input power to a DC output power having a set target output value by the control signal for each channel generated to have the same phase difference with each other according to the number of channels used. It is to provide a switching power supply which can be controlled individually and can be miniaturized and reduced in cost, and a control method thereof.

The present invention to solve the above problems, the input unit for supplying a direct current input power to a plurality of channels; An output unit having a plurality of channels for converting the input power into a DC output power having a target output value by switching input power according to a control signal provided for each channel; And a control unit which receives the output value of the output power for each channel and generates a pulse width modulated control signal based on the fed back output value and the target output value, and provides the control signal for each channel to perform pulse width modulation control. The provided control signal is generated to have the same phase difference from each other according to the number of channels, to provide a switching power supply for controlling a plurality of outputs.

On the other hand, the present invention to achieve the above object, (a) setting the number of channels and the target output value for each channel according to the initial value; (b) determining the phase of the control signal for each channel according to the number of channels such that the phase differences of the control signals provided for each channel are equal to each other; (c) generating a control signal for each channel according to the target output value according to the determined phase; (d) converting the input power for each channel into an output power of DC having a target output value by switching based on the generated control signal; And (e) receiving feedback of the output value of the output power for each channel, and controlling pulse width modulation of the control signal for each channel based on the fed back output value and the target output value. Provide a method.

According to the present invention, by performing the PWM control using a control signal having the same phase difference with respect to the plurality of channels, it is possible to control the plurality of channels individually, to balance the phase for the plurality of channels, Switching noise generated at the output stage and ripple noise of the output can be reduced.

In addition, according to the present invention, by implementing each component constituting the control unit by a software algorithm using a processor and a digital PWM signal, etc., it is possible to miniaturize the switching power supply, reduce power consumption, and reduce manufacturing costs.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a block diagram of a switching power supply according to the present invention.

Referring to FIG. 1, the switching power supply 100 according to the present invention includes an input unit 110, an output unit 120, and a controller 130, and further includes a communication unit 140.

The input unit 110 is a component that receives a DC power supply (V _IN ) and supplies it to a plurality of channels (CH ₁ to CH _N ). 112 and an input filter unit 114 for removing noise of power supplied from the outside.

The output unit 120 receives DC input power V _IN through a plurality of channels CH ₁ to CH _N , and outputs DC output power V _{OUT 1} to V _OUTN having a target output value for each channel. It converts to) and outputs it.

The output unit 120 includes a plurality of output units 120_1 to 120_n. Each output unit receives DC input power from the input unit 110 through the corresponding channel, converts the DC output power with the target output value, and outputs the output power to the corresponding channel. For example, the first output unit 120_1 receives the input power V _IN from the input unit 110 through the first channel CH ₁ , and converts the input power V _IN to the output power V _OUT1 . Is output to the first channel CH ₁ .

On the other hand, each output unit includes a switching unit 122 for switching the input power by a control signal, and an output filter 124 to smooth the voltage of the output power and remove noise.

The switching unit 122 switches the input power by the control signal provided by the control unit 130, thereby converting the input power into output power of direct current having a target output value.

The control unit 130 receives the output value of the output power for each channel, generates a control signal that is pulse width modulated (“PWM”) based on the fed back output value and the target output value of the output power, and provides it for each channel. Thereby performing pulse width modulation control.

Meanwhile, as will be described later, the controller 130 may perform setting and changing of the switching power supply 100, determining a phase of a control signal, protecting an output power and monitoring an output value, determining a type of a secondary battery, and various functions. Can be.

The communicator 140 is an interface that enables communication with an external peripheral device. The communicator 140 is used to set the switching power supply 100 or change a set value in cooperation with the controller 130. The interface of the communication unit 140 includes various serial asynchronous communication interfaces (RS232, RS485, USB, IRDA), serial synchronous communication interfaces (SPI, I2C), and asynchronous communication interfaces (LIN, CAN, KW2000, FLEXLAY) used in automobiles. It includes a communication interface.

FIG. 2 is a detailed block diagram illustrating the controller of FIG. 1.

In FIG. 2, for convenience of description, only the first channel CH ₁ is illustrated, but the controller 130 individually performs setting for each channel, and individually monitors and protects the output of each channel. In response to the output value of each channel, the control signal is generated for each channel to perform PWM control for each channel.

Referring to FIG. 2, the controller 130 may include a PWM controller 131 and a phase controller 132, and may further include an output monitor 133, a setting unit 134, and a charging control unit 135. Can be.

The PWM controller 131 is a component that performs PWM control and provides a control signal C ₁ to the switching unit 122_1. Here, the control signal is a pulse width modulated signal, which is a switching signal provided to a switch means (for example, a switch element such as an MOS-FET) included in the switching unit 122_1.

The PWM (pulse width modulation) control method controls the ratio of the output voltage to the input voltage by adjusting the pulse width of a pulse signal having a constant switching frequency.Increasing the pulse width increases the output voltage and decreases the pulse width. To reduce the output voltage.

On the other hand, in relation to the switching frequency, increasing the switching frequency eliminates ripple in the output voltage, thereby clearing the output and reducing the size of the inductor and capacitor used to switch. Reducing the switching frequency, on the other hand, increases the switching losses, thereby reducing the efficiency of the circuit.

Since PWM control is a commonly used control method, other detailed descriptions thereof will be omitted.

The PWM controller 131 receives the output value of the output power for each channel and modulates a pulse width based on the target output value and the fed back output value of the input power and the output power for each channel to generate a control signal according to the set switching frequency. . The control signal generated for each channel is provided to the switching unit of the corresponding channel, thereby controlling each switching unit to generate output power having a corresponding target output value for the input power for each channel.

The phase controller 132 determines phases of the control signals so that the control signals have the same phase difference with each other according to the number of channels. The phase of the control signal is determined according to the number of channels, in particular, the number of channels used among the plurality of channels. For example, when three channels are used, the phases of the three control signals are adjusted so that the phase difference occurs by 120 °. The phase is determined (360 ° / 3 = 120 °).

As such, by performing PWM control using a control signal having the same phase difference with respect to the plurality of channels, the plurality of channels can be individually controlled, the phases of the plurality of channels can be balanced, and generated at the plurality of output stages. The switching noise and the ripple noise of the output can be reduced.

3 is a diagram illustrating a pulse generator according to the number of channels.

The control signal is a pulse signal whose pulse width is adjusted according to the fed back output value, and is generated by adjusting the pulse width of the reference pulse signal. This reference pulse signal is generated by a pulse generator, and FIG. 3 illustrates an algorithm for generating pulse signals having the same phase difference from each other.

In FIG. 3, three channels are used, and the switching frequency is 600 kHz. If three channels are used, three control signals need to be generated, so that the phases of the control signals are 120 ° apart from each other.

The top graph shows a timer that repeats increasing at a constant rate from 0 to 600 over a period of 600 kHz. When three pulse signals P ₁ to P ₃ are generated to generate pulses at the moment of reaching the values of 0, 200, and 400, the phases of the respective pulse signals are different from each other by 120 °. Using a pulse generator using such an algorithm, it is possible to control so that the phase of the control signal is equally different according to the number of channels used. The algorithm for generating a pulse signal according to the number of channels is only one example, and the present invention can generate a pulse signal having the same phase difference according to the number of channels in various ways.

2 will be described again.

The setting unit 134 is provided with the setting information S from the communication unit 140, and according to the setting information S, initial values (switching frequency, number of channels, channels used, and channels for each channel) of the switching power supply device 100. Setting of the target output value, etc.), setting of the switching frequency, setting of the use channel to be used among the plurality of channels, setting of the target output value (target voltage value and / or target current value) for each channel, and setting of the target output value of the charging channel. Perform various setting operations and setting changes. The value set by the setting unit 134 is provided to the phase control unit 132 and the PWM control unit 131.

On the other hand, the setting unit 134 may perform the above operation for each channel as well as start, stop, restart of the entire switching power supply 100 by communication with the communication unit 140.

The output monitoring unit 133 detects whether an overcurrent or a short circuit occurs for each channel by calculating a duty value of the control signal for each channel, and stops providing the control signal to the channel where the overcurrent or short circuit occurs.

Whether an overcurrent or a short circuit occurs is determined according to the calculated duty value. The output monitoring unit 133 determines that the calculated duty value is greater than the first limit value and less than the second limit value as an overcurrent, and the calculated duty value is the second duty value. If it is more than the limit value, a short circuit is determined. Here, the first limit value and the second limit value are preferably determined to be values corresponding to 120% and 200% of the rated current, respectively.

In the conventional switching power supply, a detection circuit connected to an output terminal has to be configured in hardware in order to detect an overcurrent and a short circuit. However, in the present invention, a processor serving as a controller can detect an overcurrent and a short circuit by calculating a duty value. The size and manufacturing cost of the switching power supply can be reduced.

4 is a diagram for explaining a duty value calculation of a control signal.

4 shows an equivalent circuit of a switching power supply for one channel, and the duty value of the control signal C is expressed as follows.

The input voltage V _IN of the input power supply and the voltage drops V _Q1 and V _Q2 at the switch means Q ₁ and Q ₂ are predetermined, and the voltage V _L at the inductor _L is V _Q1. and since the output determined by the output voltage (V _OUT) of the power supply, the duty value of the control signal (C) may be computed by the output voltage (V _OUT) of the output power value.

Values necessary for calculating the duty value of the control signal are provided to the output monitoring unit 133, so that the output monitoring unit 133 can directly calculate the duty value of the control signal for each channel. Meanwhile, the duty value of the control signal may be calculated by the PWM controller 131, or the duty value may be determined according to the pattern of the output power. In this case, the calculated or determined duty value is provided to the output monitor 133.

The charging control unit 135 instructs the PWM control unit 131 to provide a charging control signal for generating a constant voltage and a constant current to the charging channel, and analyzes the output of the charging channel to determine the type of the secondary battery. The impedance of the output terminal in the charging channel may be measured by the duty value of the constant voltage, the constant current, and the charge control signal from the PWM controller, which is supplied to the charging channel, thereby determining the type of the secondary battery.

 In addition, the charging control unit 135 provides the setting unit 134 with the determined type of the secondary battery, so that the setting unit 134 may set a target output value suitable for the type of the secondary battery for the charging channel. To this end, the setting unit 134 stores information on a target output value according to each type of secondary battery.

Here, the charging channel is a channel prepared in advance for charging the secondary battery, and may be provided in any one channel of the output unit 120.

The above-described control unit 130 and each component constituting the control unit are implemented by a software algorithm using a processor having an arithmetic and logic unit (ALU) logic, a digital PWM signaler, and an analog to digital converter (ADC). This makes it possible to miniaturize switching power supplies, reduce power consumption, and reduce manufacturing costs.

Hereinafter, the output control method of the switching power supply according to the present invention will be described in sequence. Since the function of the output control method of the switching power supply according to the present invention is essentially the same as the function and operation of the switching power supply, overlapping portions will be omitted.

5 is a flowchart illustrating an output control method of a switching power supply according to the present invention, FIG. 6 is a flowchart illustrating the initialization step of FIG. 5 in detail, and FIG. 7 is a flowchart illustrating the output monitoring / protection step of FIG. 5 in detail.

First, the controller 130 of the switching power supply apparatus performs an initialization process of setting the number of channels and the target output value for each channel according to the initial value (S10).

The initial value includes information on the number of channels and the target output value for each channel. The initial value may further include information on a switching frequency value and a use channel.

The controller 130 of the switching power supply apparatus sets a number of channels according to the initial value (S11), sets a switching frequency of a control signal (S12), and includes a target voltage value and a target current value for each channel. The output value is set (S13).

After the initialization process, the control unit 130 of the switching power supply device determines the phase of the control signal for each channel according to the set number of channels so that the phase difference of the control signals provided for each channel is equal to each other (S20).

On the other hand, when it is necessary to change the setting value of the switching power supply (S30), the control unit 130 of the switching power supply communicates from the external peripheral through the communication unit 140.

The control unit 130 of the switching power supply unit sets the switching frequency value according to the setting information S provided from the communication unit 140, the setting of the use channel to be used among the plurality of channels, and the target output value for each channel (target voltage value). And / or setting a target current value) and setting a target output value of the charging channel.

Although this setting operation is shown in FIG. 5 as being performed after the initialization of the switching power supply, it is natural that the switching power supply may also be performed during operation.

The controller 130 of the switching power supply device generates a control signal corresponding to the determined phase and the target output value for each channel (S50).

Each output unit 120 of the switching power supply device converts the input power for each channel into a DC output power having a set target output value by switching by the generated control signal (S60).

The control unit 130 of the switching power supply receives the output value of the output power for each channel, and PWM control the control signal for each channel based on the feedback output value and the target output value (S70).

On the other hand, the control unit 130 of the switching device monitors and protects the output of the output power for each channel (S80).

To this end, the controller 130 of the switching device calculates the duty value of the control signal for each channel (S81), detects whether an overcurrent or a short circuit occurs according to the calculation result of the duty value (S83, S84), and overcurrent or a short circuit. If this is detected, the supply of the control signal to the channel in which the overcurrent or short circuit occurs is stopped (S85).

The method of the present invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

In the above described the present invention with reference to the specific embodiment shown in the drawings, but this is only an example, those of ordinary skill in the art to which the present invention pertains various modifications and variations therefrom. Therefore, the protection scope of the present invention should be interpreted by the claims to be described later, and all the technical ideas within the equivalent and equivalent ranges should be construed as being included in the protection scope of the present invention.

1 is a block diagram of a switching power supply according to the present invention.

2 is a block diagram illustrating in detail the control unit of FIG. 1;

3 illustrates a pulse generator according to the number of channels.

4 is a diagram for explaining duty value calculation of a control signal;

5 is a flowchart illustrating an output control method of a switching power supply according to the present invention.

6 is a flow chart showing in detail the initialization step of FIG.

7 is a flowchart detailing the output monitoring / protection step of FIG.

Claims (7)

An input unit for supplying DC input power to a plurality of channels; By switching the input power supplied to the plurality of channels by a control signal provided for each channel, the input power supplied to the plurality of channels is converted into a direct current output power having a target output value for each channel for each channel. An output unit converting each to provide a plurality of output powers; And The output values of the plurality of output powers are fed back for each channel, and the control signals are pulse-modulated based on the output value fed back to each channel and the target output value for each channel, and generated for each channel. By providing a control unit for performing the pulse width modulation control, And the control signal provided for each channel is generated to have the same phase difference with each other according to the number of channels. The method of claim 1, wherein the control unit Computing the duty value of the control signal for each channel to detect the occurrence of overcurrent or short circuit in each channel, and stops providing the control signal to the channel overcurrent or short circuit occurs, a plurality of outputs Switching power supply to control. The switching power supply of claim 1, wherein Further comprising a communication unit for performing communication with an external device, The control unit may set at least one of a number of channels, a channel used, a target output value for each channel, and a switching frequency value of the control signal by communication of the communication unit. The method of claim 1, The output unit includes a charging channel for charging the secondary battery, The controller may be configured to provide a charging control signal for generating a constant voltage and a constant current to the charging channel, analyze the output of the charging channel to determine the type of the secondary battery, and determine the charging according to the type of the secondary battery. A switching power supply for controlling a plurality of outputs, characterized by setting a target output value of the channel. (a) setting a channel number and a target output value for each channel for each channel according to the initial value; (b) determining the phase of the control signal for each channel according to the number of channels such that the phase differences of the control signals provided for each channel are equal to each other; (c) generating a control signal for each channel according to the determined phase and the target output value for each channel; (d) switching input power based on the control signal generated for each channel, thereby converting the input power into output power of direct current having a target output value for each channel, thereby converting a plurality of output powers according to the number of channels. Providing; And (e) receiving feedback of output values of the plurality of output powers for each channel, and performing pulse width modulation control of the control signal for each channel based on the output value fed back for each channel and the target output value for each channel; An output control method of a switching power supply, characterized in that it comprises. The method of claim 5, wherein the method and (f) changing a setting of at least one of a number of channels, a channel used, a target output value for each channel, and a switching frequency value of the control signal by communication with an external device. How to control the output of the device. The method of claim 5 or 6, wherein the method (g) calculating a duty value of the control signal for each channel; (h) detecting whether an overcurrent or a short occurs in each channel according to the calculation result of the duty value; And (i) if the overcurrent or short circuit is detected, stopping the provision of the control signal for the channel in which the overcurrent or short circuit occurs.

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