Power supply unit and its control method

Abstract

This invention discloses a power supply device and a control method thereof. [Solution] The power supply device is a power conversion unit that performs power conversion based on an input power supply and generates an output current, and includes a power conversion unit having a power output terminal and outputting the output current from the power output terminal; a sampling circuit electrically connected to the power output terminal of the power conversion unit and used to sample transient changes in the output current and generate an output voltage difference signal corresponding to the width of the transient change based on this sampling circuit; and a signal comparison unit electrically connected to the current sampling circuit and receiving the output voltage difference signal and comparing the output voltage difference signal with a predetermined voltage value, wherein when the output voltage difference signal is greater than or equal to the predetermined voltage value, the signal comparison unit generates a dynamic correction command.

Description

Technical Field

[0001] The present invention discloses a power supply device and a control method thereof, and particularly relates to a power supply device that generates a correction control command when detecting that the output load current with a dynamically responsive abrupt change using a current feedback signal as a trigger control command, and a control method thereof.

Background Art

[0002] Please refer to FIG. 5A. FIG. 5A is a circuit schematic diagram of a conventional server power supply device for detecting dynamic response of an output. The circuit of FIG. 5A includes a power converter 21, an output capacitor C out and a load resistor R L and a voltage divider 22 and an analog / digital proportional integral controller 23. The power converter 21 is electrically connected to a power supply P, and after converting an input signal of the power supply P, the signal is provided for transmission to the output capacitor C out and the load resistor R L The output voltage V L signal on the load resistor R out generates a divided voltage V FB after passing through the voltage divider 2, and is input to the analog / digital proportional integral controller 23. Regarding the detection of dynamic load response, in the current method, usually, detection is performed on the output voltage V out When the pumping of the output voltage V out is large, it will cause a drop in the output voltage V out at the load end. When the voltage drops, it must be detected in real time to raise the output voltage V out at the time of the drop of the output voltage V out For this reason, after the output voltage V

[0003] in the circuit of FIG. 5A is fed back by voltage, that is, after generating a divided voltage V out through the voltage divider 22, and after generating a command value to be input to the analog / digital proportional integral controller 23, the divided voltage V FB can be obtained. FBOutput voltage V out It is not possible to perform voltage correction after the change in the output voltage V is known. However, since it is limited by the size of the bandwidth, the voltage loop controller in Figure 5A can correct the output voltage V out To detect changes in the dynamic response and improve the fact that control signals can no longer react in real time, conventional circuit configurations are no longer suitable. In other words, conventional voltage loop controllers are limited by bandwidth speed and cannot improve response speed. However, the pumping speed of load current has already improved from 0.5 A / μs to 2.5 A / μs and even to 10 A / μs, and as the pumping speed increases further, methods of detecting voltage load fluctuations via general analog / digital proportional-integral controllers can no longer keep up with the pumping speed.

[0004] Please refer to Figures 5B and 5C. Figure 5B is a simulation circuit diagram of the voltage loop signal in Figure 5A, and Figure 5C is a schematic diagram of the bandwidth and current pumping speed of the circuit in Figure 5A. In the simulation circuit diagram of Figure 5B, the simulation circuit uses the current server power supply to provide the output capacitor and analyzes simulations performed at the circuit bandwidth (BW) for output loads from 0A to 100A with a load change rate of 2.5A / μs. Of these, BW_2k represents a typical bandwidth signal of 2kHz in a general voltage loop, and BW_44k is the calculated required loop bandwidth of 44kHz. As shown in Figure 5C, since most of the bandwidth of the current voltage loop controller is in the range of 2K (BW_2k in Figure 5C) to 4K, the output voltage V out (V in Figure 5C) out It is not possible to detect the rate of change of the output voltage V in real time. However, if the bandwidth is insufficient and the change in the dynamic load response cannot be detected in real time, then by solving the problem of insufficient bandwidth and increasing the bandwidth, the output voltage V outTo detect changes in real time, the circuit bandwidth must be increased to 44K (BW_44k in Figure 5C). However, designing a voltage cycle controller with a 44K bandwidth is difficult, as it requires realizing and completing a corresponding power supply, and is prone to causing instability in the entire system. Therefore, this type of approach is not practical and cannot be widely used. Among these, the output current I in Figure 5C out As can be seen from line Y2, the output current I out and output voltage V out When fluctuations occur over a time period of approximately 60 μs, using a 2 kHz bandwidth signal is simply not enough to keep up with the speed of load fluctuations.

[0005] Please refer to Figure 6, a schematic circuit diagram showing the detection of the dynamic response of the output using a comparator. The circuit in Figure 6 consists of a power converter 21 and an output capacitor C. out And the load resistor R L This includes a voltage divider resistor 22 and a comparator 24. Similarly, the power converter 21 is electrically connected to the power supply P and, after converting the input signal of the power supply P, outputs the signal to the output capacitor C out and load resistance R L Used for transmission, output voltage V out The divided voltage V passes through the voltage divider resistor 22. FB After generating the voltage, comparator 24 uses one reference voltage V REF and divided voltage V FB By comparing it with the output voltage V out It detects the dynamic change of this output voltage V. out and reference voltage V REF In a detection method that compares the output voltage V out If no change has already occurred, then the output voltage V has already changed. out and reference voltage V REF It is not possible to compare them. Therefore, by using this type of voltage feedback signal to detect the voltage drop, and thereby changing the trigger control command, after a certain period of time has elapsed, the output signal (output voltage V outEven with a method that detects the dynamic response of the output using comparator 24 after a change has already occurred, the effect of real-time detection cannot be achieved, and the output voltage falls below the adjustment voltage specified by the power supply.

[0006] Therefore, providing a power supply device and control method that can detect changes in dynamic response in real time and correct the output signal is currently an urgent research topic. [Overview of the project] [Means for solving the problem]

[0007] The present invention discloses a power supply device including a power conversion unit, a current sampling circuit, and a signal comparison unit, as well as a control method thereof. The power conversion unit is used to perform power conversion based on an input power supply and generate an output current, and has a power output terminal and outputs the output current from the power output terminal. The current sampling circuit is electrically connected to the power output terminal of the power conversion unit and is used to sample transient changes in the output current and generate an output voltage difference signal corresponding to the width of the transient change based on this sampling. The signal comparison unit is electrically connected to the current sampling circuit and receives the output voltage difference signal, compares the output voltage difference signal with a predetermined voltage value, and when the output voltage difference signal is greater than or equal to the predetermined voltage value, the signal comparison unit generates a dynamic correction command.

[0008] Therefore, in the power supply device and control method of the present invention, a current feedback signal is used as a trigger control command to detect a sudden change in the output load current during dynamic response, and the control command for the converter is corrected in advance, thereby facilitating the adjustment of the voltage within the adjustment voltage range before the output voltage exceeds the voltage adjustment range. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a schematic block diagram of the power supply device of the present invention. [Figure 1B] Figure 1A is a schematic block diagram of the current sampling circuit in the power supply unit, which includes a voltage signal conversion unit, a voltage signal amplification unit, a voltage signal processing unit, and a signal difference unit. [Figure 1C] Figure 1B is a schematic circuit diagram of the power supply unit. [Figure 2] This is a schematic diagram of the waveform change in the dynamic load response. [Figure 3] This is a flowchart of the steps for the control method of the power supply device of the present invention. [Figure 4A] This is a schematic diagram of a simulation design using analog circuits. [Figure 4B] This is a schematic diagram of the signal simulation results. [Figure 5A] This is a schematic diagram of a conventional server power supply that detects the dynamic response of its output. [Figure 5B] Figure 5A is a simulation circuit diagram of a voltage loop signal. [Figure 5C] Figure 5A is a schematic diagram of the circuit bandwidth and current pumping speed. [Figure 6] This is a schematic diagram of a circuit that detects the dynamic response of the output using a conventional comparator. [Modes for carrying out the invention]

[0010] Please refer to Figure 1A, a schematic block diagram of the power supply device of the present invention. The power supply device 1 includes a power conversion unit 10, a current sampling circuit 11, and a signal comparison unit 16. The power conversion unit 10 performs power conversion based on the input power supply P and outputs current I out It is used to generate the output current I, and the power conversion unit 10 has a power output terminal, and the power conversion unit 10 receives the output current I from the power output terminal. out The current sampling circuit 11 is electrically connected to the power output terminal of the power conversion unit 10, and outputs the output current I out The transient changes are sampled, and based on this, an output voltage difference signal V corresponding to the width of the transient change is generated. diffIt is used to generate the output voltage difference signal V. The signal comparison unit 16 is electrically connected to the current sampling circuit 11 and is used to generate the output voltage difference signal V. diff It receives the output voltage difference signal V diff set to a predetermined voltage value V th Compare with the output voltage difference signal V. diff The predetermined voltage value V th When the above conditions are met, the signal comparison unit 16 will issue the dynamic correction command V cmd This generates [the following]. In embodiments of the present invention, the input power supply P includes a commercial power supply, a socket, or other power source.

[0011] Please refer to Figure 1B, which is a schematic block diagram of the current sampling circuit 11 in the power supply unit 1 of Figure 1A, including a voltage signal conversion unit 12, a voltage signal amplification unit 13, a voltage signal processing unit 14, and a signal difference unit 15. In this embodiment, the power supply unit 1 includes a power conversion unit 10, a current sampling circuit 11, and a signal comparison unit 16, and the current sampling circuit 11 includes a voltage signal conversion unit 12, a voltage signal amplification unit 13, a voltage signal processing unit 14, and a signal difference unit 15. The power conversion unit 10 is electrically connected to the power supply P and outputs the input signal of the converted power supply P as an output current I out The power conversion unit 10 is used for this purpose, and the power conversion unit 10 has a power output terminal, and the power conversion unit 10 receives the output current I from the power output terminal. out The output is such that the input signal to power supply P includes either AC or DC current. Output capacitor C is connected to the power output terminal of power conversion unit 10. out A voltage signal conversion unit 12 is electrically connected to the power output terminal and load terminal of the power conversion unit 10, and the output current I out output voltage signal V out It is converted to a load resistor R at the load end. L A voltage signal amplification unit 13 is provided. The voltage signal amplification unit 13 is electrically connected to the voltage signal conversion unit 12, the load terminal and the power supply output terminal, and the output voltage signal V out By amplifying the output voltage signal V i1The voltage signal processing unit 14 is electrically connected to the voltage signal amplification unit 13 to generate the amplified output voltage signal V. i1 By delaying the change, the delayed output voltage signal V i2 This generates the amplified output voltage signal V by the voltage signal processing unit 14. i1 By delaying the change, the delayed output voltage signal V i2 The phase change is amplified into the output voltage signal V i1 It is delayed compared to the phase change. The signal difference unit 15 is electrically connected to the voltage signal amplification unit 13 and the voltage signal processing unit 14, and the amplified output voltage signal V i1 and delayed output voltage signal V i2 By receiving and comparing the output voltage difference signal V diff The signal comparison unit 16 generates the output voltage difference signal V. The signal comparison unit 16 is electrically connected to the signal difference unit 15 and outputs the output voltage difference signal V. diff It receives the output voltage difference signal V diff set to a predetermined voltage value V th Compare with the output voltage difference signal V. diff The predetermined voltage value V th When the above conditions are met, the signal comparison unit 16 will issue the dynamic correction command V cmd Generates.

[0012] Please refer to Figure 1C, which is a schematic circuit diagram and a schematic power supply block diagram in Figure 1B. In this embodiment of the present invention, the voltage signal conversion unit 12 is a shunt resistor R shunt or includes a Hall sensor. The voltage signal amplification unit 13 includes a differential amplifier or a non-inverting amplifier. The voltage signal processing unit 14 includes a low-pass filter, an active filter, an RC filter, and a digital filter, and amplifies the output voltage signal V i1 By filtering, the delayed output voltage signal V i2 The digital filter generates the output voltage signal V. i1 By filtering, the delayed output voltage signal V i2generates the steady-state average value. The signal difference unit 15 compares the steady-state average value of the amplified output voltage signal V i1 with the steady-state average value of the delayed output voltage signal V i2 to generate an output voltage difference signal V diff . The signal difference unit 15 includes a differential amplifier and an analog comparator or a digital comparator. The signal comparison unit 16 includes an analog comparator, a Schmitt hysteresis circuit, or a digital comparator.

[0013] In an embodiment of the present invention, the voltage signal processing unit 14 includes a storage unit that stores and averages a plurality of amplified output voltage values in the amplified output voltage signal V i1 to generate a delayed output voltage average value of the delayed output voltage signal V i2 based on the plurality of amplified output voltage values. The signal difference unit 15 compares the amplified output voltage signal V i1 with the delayed output voltage average value of the delayed output voltage signal V i2 to generate an output voltage difference signal V diff . In an embodiment of the present invention, the storage unit is a register that stores a plurality of amplified output voltage values V i1 at a predetermined sampling period, for example, stores a plurality of amplified output voltage values V i1 at a predetermined sampling period per second.

[0014] Please refer to FIG. 2, which is a schematic diagram of the waveform change of the dynamic load response. As shown in FIG. 2, when a large amount of pumping occurs at the load end in a situation where the signal delay processing by the voltage signal processing unit 14 is not performed on the amplified output voltage signal V i1 , a rapid change occurs in the dynamic load response. After delaying the signal change of the amplified output voltage signal V i1 by filtering or averaging the amplified output voltage signal V i1 , the change of the amplified output voltage signal V i1 becomes gentle, thereby generating a delayed output voltage signal V i2 with a slow change speed. Further, by the above-described storage unit, at different first time point T1, second time point T2, and third time point T3, the amplified output voltage signal V i1and the delayed output voltage signal V i2 Extract and save the numerical values of, and compare the difference in the signal changes. Taking the first time point T1 and the second time point T2 as an example, for the amplified output voltage signal V i1 and the delayed output voltage signal V i2 the amount of change in the difference between them is the same. That is, there is no change in the amount of difference between the amplified output voltage signal V i1 and the delayed output voltage signal V i2 Therefore, the output voltage difference signal V diff [[ID=1Z]]generated by the signal difference unit 15 is not equal to or greater than the predetermined voltage value V th On the other hand, at the third time point T3, the amount of change in the difference between the amplified output voltage signal V i1 and the delayed output voltage signal V i2 increases, and when the output voltage difference signal V diff generated by the signal difference unit 15 is equal to or greater than the predetermined voltage value V th through comparison by the signal comparison unit 16, it can be seen that a large amount of pumping is occurring exactly at the load end at the current stage. Therefore, the signal comparison unit 16 generates a dynamic correction command V cmd and executes the dynamic correction mechanism.

[0015] For this reason, after the storage unit stores a plurality of amplified output voltage values, at least one amplified output voltage value among the plurality of amplified output voltage values and the delayed output voltage signal V i2 are compared by the signal difference unit 15 to generate at least one output voltage difference signal V diff The signal comparison unit 16 receives at least one output voltage difference signal V diff and compares at least one output voltage difference signal V diff with a predetermined voltage value V th When at least one output voltage difference signal V diff is equal to or greater than the predetermined voltage value V th the signal comparison unit 16 generates at least one dynamic correction command V cmd Furthermore, the signal comparison unit 16 generates a plurality of dynamic correction commands V cmd ] based on the comparison results of the signal comparison unit 16 for multiple times.When generating, multiple corrections can be performed in separate steps. For example, the signal comparison unit 16 can perform three dynamic correction commands V cmd When generating this, three dynamic correction commands V cmd The output can be divided into three stages for correction.

[0016] Please refer to Figure 3, which is a flowchart of the steps of the power supply control method of the present invention. The power supply control method includes the following steps. In step S11, the power conversion unit performs power conversion based on the input power supply and generates an output current. In step S12, the current sampling circuit samples the transient change of the output current and generates an output voltage difference signal corresponding to the width of the transient change based on this sample. In step S13, the signal comparison unit receives the output voltage difference signal and compares the output voltage difference signal with a predetermined voltage value. In step S13, if the output voltage difference signal is greater than or equal to the predetermined voltage value, step S14 is executed and the signal comparison unit issues a dynamic correction command V cmd This generates the following. In step S13, if the output voltage difference signal is not equal to or greater than a predetermined voltage value, the process returns to step S12.

[0017] Please refer to Figures 4A and 4B. Figure 4A is a schematic diagram of a simulation design using an analog circuit, and Figure 4B is a schematic diagram of the signal simulation results. In the embodiments of the present invention, the use of analog circuits is not limited, and even with digital control, it can be completed using the concept in Figure 1C. In Figure 4A, the load is simulated and set to reach 200A with a gradient of 2.5A / us, and a control mode is set that triggers dynamic correction when there is a negative fluctuation of 50A. From the solid line in Figure 4B, the dynamic response V occurs approximately 20μs after the load fluctuation occurs. T It can be triggered, and the response time is significantly shorter than that of conventional voltage feedback control methods (generally, it takes at least 60 μs to determine that a change has occurred in the load).

[0018] It should be noted here that the simulation results in Figures 4A and 4B mainly show that by adopting the power supply device of the embodiment of this application, the response time is significantly shorter than that of the conventional voltage detection control method, and the control of the output current of the power supply device becomes even more stable. The resistors R1 to R13, capacitors C1 to C4, voltages V1 to V5, and V are all mentioned in Figures 4A and 4B. d1 , V d2 , V out , V T , current I out The specific numerical values ​​of time are merely illustrative of an example in one embodiment of the present application, and the application is not limited thereto.

[0019] In summary, the power supply device and its control method of the present invention use a current feedback signal as a trigger control command to detect the voltage response of the dynamic current, and thereby detect when the output load current changes rapidly during the dynamic response. By pre-triggering and generating a control command for the converter, it is made easier to adjust the voltage to the adjustment voltage range before the output voltage exceeds the voltage adjustment range. [Explanation of Symbols]

[0020] 1 Power supply P power supply 10 Power Conversion Units 11 Current sampling circuit 12 Voltage signal conversion unit 13 Voltage signal amplification unit 14 Voltage signal processing unit 15 Signal Difference Unit 16 Signal Comparison Unit 21 Power Converters 22 Voltage divider resistors 23 Analog / Digital Proportional-Integral Controllers 24 Comparator S11~S14 Step I out Output current C out Output capacitor V outOutput voltage signal R L Load resistance R shunt Shunt resistor V i1 Amplified output voltage signal V i2 Delayed output voltage signal V diff Output voltage difference signal V th predetermined voltage value V cmd Dynamic correction command V T Dynamic response V d1 First voltage terminal V d2 Second voltage terminal

Claims

1. A power conversion unit that performs power conversion based on an input power supply and generates an output current, the power conversion unit having a power output terminal and outputting the output current from the power output terminal, A current sampling circuit is electrically connected to the power output terminal of the power conversion unit described above, which samples the transient change of the output current and generates an output voltage difference signal corresponding to the width of the transient change based on this sampling circuit. A signal comparison unit is electrically connected to the above current sampling circuit to receive the above output voltage difference signal and to compare the above output voltage difference signal with a predetermined voltage value. A power supply device including, A power supply device characterized in that when the above output voltage difference signal is greater than or equal to the above predetermined voltage value, the above signal comparison unit generates a dynamic correction command.

2. The above current sampling circuit is, A voltage signal conversion unit is electrically connected to the power output terminal of the power conversion unit and converts the output current into an output voltage signal. A voltage signal amplification unit is electrically connected to the above voltage signal conversion unit and generates an amplified output voltage signal by amplifying the above output voltage signal, A voltage signal processing unit is electrically connected to the above voltage signal amplification unit and generates a delayed output voltage signal by delaying the change in the amplified output voltage signal. A signal difference unit is electrically connected to the above-mentioned voltage signal amplification unit and the above-mentioned voltage signal processing unit, and receives and compares the amplified output voltage signal and the delayed output voltage signal to generate the output voltage difference signal and supply it to the signal comparison unit. The power supply device according to claim 1, including the following:

3. The power supply device according to claim 2, wherein the voltage signal conversion unit includes a shunt resistor or a Hall sensor.

4. The power supply device according to claim 2, wherein the voltage signal amplification unit includes a differential amplifier or a non-inverting amplifier.

5. The power supply device according to claim 2, wherein the voltage signal processing unit includes a low-pass filter, an active filter, and an RC filter or a digital filter, and generates the delayed output voltage signal by filtering the amplified output voltage signal.

6. The above digital filter generates the steady-state average value of the delayed output voltage signal by filtering the above amplified output voltage signal. The power supply device according to claim 5, wherein the signal difference unit generates the output voltage difference signal by comparing the amplified output voltage signal and the delayed output voltage signal with the steady-state average value.

7. The power supply device according to claim 2, wherein the above-mentioned signal difference unit includes a differential amplifier and an analog comparator or a digital comparator.

8. The power supply device according to claim 1, wherein the signal comparison unit includes an analog comparator and a Schmidt hysteresis circuit or a digital comparator.

9. The above voltage signal processing unit includes a storage unit that stores and averages multiple amplified output voltage values ​​of the amplified output voltage signal to generate the average delayed output voltage value of the delayed output voltage signal based on the multiple amplified output voltage values. The power supply device according to claim 2, wherein the signal difference unit generates the output voltage difference signal by receiving and comparing the amplified output voltage signal and the average value of the delayed output voltage of the delayed output voltage signal.

10. The power supply device according to claim 9, wherein the storage unit stores the plurality of amplified output voltage values ​​at a predetermined sampling period.

11. The power conversion unit performs power conversion based on the input power supply and generates an output current; The process involves sampling the transient change of the output current using a current sampling circuit, and generating an output voltage difference signal corresponding to the width of the transient change based on this sampling. The signal comparison unit receives the above output voltage difference signal and compares the above output voltage difference signal with a predetermined voltage value. A method for controlling a power supply device, including, A control method for a power supply device, characterized in that when the output voltage difference signal is greater than or equal to the predetermined voltage value, the signal comparison unit generates a dynamic correction command.

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