Power supply and control method thereof

Abstract

The invention discloses a power supply and a control method thereof. The power supply comprises a power conversion unit used for performing power conversion based on an input power supply and generating an output current; wherein the power conversion unit is provided with a power output end, and the power conversion unit outputs the output current from the power output end; the current sampling circuit is electrically connected with the power output end of the power conversion unit and is used for sampling the transient change of the output current and generating an output voltage difference signal reflecting the amplitude of the transient change according to the transient change; the signal comparison unit is electrically connected with the current sampling circuit, receives the output voltage difference signal and compares the output voltage difference signal according to a preset voltage value; when the output voltage difference signal is greater than or equal to a preset voltage value, the signal comparison unit generates a dynamic compensation instruction.

Description

Technical Field

[0001] This invention discloses a power supply and its control method, particularly a power supply and its control method that uses a current feedback signal as a trigger control command to generate a compensation control command when a rapid change in the output load current of a dynamic response is detected. Background Technology

[0002] Please see Figure 5A , Figure 5A A circuit diagram for detecting the dynamic response of an existing server power supply output. Figure 5A The circuit includes a power converter 21 and an output capacitor. Load resistance The circuit includes voltage divider resistors 22 and an analog / digital proportional-integral controller 23. The power converter 21 is electrically connected to power supply P, and after converting the input signal of power supply P, transmits the signal to the output capacitor. and load resistance load resistance Output voltage The signal, after passing through voltage divider resistor 22, generates a voltage divider voltage. This data is then input to the analog / digital proportional-integral controller 23. Current methods for detecting dynamic load response typically involve monitoring the output voltage. Detection is performed, and when the output voltage... When the load is large, it causes the output voltage at the load terminal to be high. A drop in voltage must be detected immediately in order to adjust the output voltage accordingly. Increase output voltage when it drops .

[0003] In conclusion, Figure 5A Output voltage in the circuit After voltage feedback, that is, after voltage divider resistor 22 generates a voltage divider voltage. Afterwards, a command value is generated and input to the analog / digital proportional-integral controller 23, which can then be used to control the voltage divider. Know the output voltage Voltage compensation is performed after the change. However, due to bandwidth limitations, it is possible to achieve the desired voltage through... Figure 5A The voltage loop controller detects the output voltage. The dynamic response to changes in load current and the improvement of control signals can no longer react in time, rendering existing circuit architectures inadequate. In other words, traditional voltage loop controllers are limited by bandwidth speed, preventing improvements in response speed. However, the current drawdown speed of load current has increased from 0.5A / μs to recently 2.5A / μs, and even to 10A / μs. As the drawdown speed increases, the conventional method of detecting voltage load changes using analog / digital proportional-integral controllers can no longer keep up with the drawdown speed.

[0004] Please see Figure 5B and Figure 5C , Figure 5B for Figure 5A Analog circuit diagram of voltage loop signal. Figure 5C for Figure 5A A schematic diagram of the circuit bandwidth and current pump-load speed. (In...) Figure 5B The simulated circuit diagram uses the current power supply to supply the output capacitor capacity, and the output load is changed from 0A to 100A at a load change rate of 2.5A / μs. Simulation analyses are performed for the line bandwidth (BW), where BW_2k represents the common 2kHz bandwidth signal of a typical voltage loop, and BW_44k is the calculated required loop bandwidth of 44kHz. For example... Figure 5C As shown, since the bandwidth of most current voltage loop controllers is between 2K (e.g., Figure 5C The bandwidth between BW_2k and 4K is insufficient to detect the output voltage in real time. (like Figure 5C In The rate of change of the load response. However, in cases where insufficient bandwidth prevents real-time detection of dynamic load response changes, increasing the bandwidth to real-time detect the output voltage is necessary to address the bandwidth shortage. Due to the changes, the circuit bandwidth must be increased to 44kHz (e.g., Figure 5C The BW_44k in the text is used, but for voltage loop controllers designed with a 44K bandwidth, it is difficult to implement and complete the corresponding power supply, and it is also easy to cause instability of the entire system. Therefore, this approach is impractical and cannot be widely used. Figure 5C Output current in As can be seen from segment Y2, when the output current and output voltage When the load changes over a period of approximately 60μs, a 2kHz bandwidth signal is far from being able to keep up with the speed of the load change.

[0005] Please see Figure 6 It is a circuit diagram that detects the dynamic response of the output through a comparator. Figure 6 The circuit includes a power converter 21 and an output capacitor. Load resistance The voltage divider resistor 22 and comparator 24 are also present. Similarly, the power converter 21 is electrically connected to the power supply P, and after converting the input signal of the power supply P, it transmits the signal to the output capacitor. and load resistance When the output voltage A voltage divider is generated by voltage divider resistor 22. Then, comparator 24 is connected to a reference voltage. With voltage divider Compare to detect the output voltage. The dynamic changes. However, this is achieved through the output voltage. and reference voltage The comparison detection method must wait until the output voltage... Only when the change has occurred can the changed output voltage be utilized. and reference voltage Comparison. Therefore, this method, which uses voltage feedback signals to detect the magnitude of voltage drop and then triggers a change in control commands, will, after a period of time, result in the output signal (output voltage) being compared. Once the voltage has changed, the method of detecting the dynamic response of the output through comparator 24 can no longer achieve the effect of real-time detection, thus causing the output voltage to be lower than the regulation voltage specified by the power supply.

[0006] Therefore, how to provide a power supply and its control method to detect dynamic response changes in real time and compensate the output signal has become an urgent research topic. Summary of the Invention

[0007] This invention discloses a power supply and its control method. The power supply includes a power conversion unit, a current sampling circuit, and a signal comparison unit. The power conversion unit is used to convert power based on an input power supply and generate an output current. The power conversion unit has a power output terminal, and the power conversion unit 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 to sample a transient change in the output current and generate an output voltage difference signal reflecting the amplitude of the transient change. The signal comparison unit is electrically connected to the current sampling circuit, receives the output voltage difference signal, and compares the output voltage difference signal with a preset voltage value. When the output voltage difference signal is greater than or equal to the preset voltage value, the signal comparison unit generates a dynamic compensation command.

[0008] This invention further discloses a power supply control method, comprising the following steps: a power conversion unit performs power conversion based on an input power supply and generates an output current; a current sampling circuit samples a transient change in the output current and generates an output voltage difference signal that reflects the amplitude of the transient change; a signal comparison unit receives the output voltage difference signal and compares it with a preset voltage value; when the output voltage difference signal is greater than or equal to the preset voltage value, the signal comparison unit generates a dynamic compensation command. .

[0009] As described above, the power supply and control method of the present invention use a current feedback signal as a trigger control command, and then, when a rapid change in the output load current is detected during dynamic response, a control command is sent to the converter in advance to compensate the output voltage to the regulated voltage range before it exceeds the voltage regulation range. Attached Figure Description

[0010] Figure 1A This is a block diagram of the power supply of the present invention;

[0011] Figure 1B for Figure 1A A block diagram showing the current sampling circuit in a power supply, which includes a voltage signal conversion unit, a voltage signal amplification unit, a voltage signal processing unit, and a signal differentiation unit.

[0012] Figure 1C for Figure 1B Circuit diagram of the power supply;

[0013] Figure 2 This is a schematic diagram of the waveform changes in dynamic load response;

[0014] Figure 3 This is a flowchart of the steps of the power supply control method of the present invention;

[0015] Figure 4A A schematic diagram for simulating the design using a simulated circuit;

[0016] Figure 4B This is a schematic diagram of the signal simulation line results;

[0017] Figure 5A A circuit diagram for detecting the dynamic response of an existing server power supply output;

[0018] Figure 5B for Figure 5A Analog circuit diagram of voltage loop signal;

[0019] Figure 5C for Figure 5A A schematic diagram of the circuit bandwidth and current pump-load speed; and

[0020] Figure 6 This is a schematic diagram of an existing circuit that detects the dynamic response of the output using a comparator. Detailed Implementation

[0021] Please see Figure 1A This is a block diagram of the power supply 1 of the present invention. The power supply 1 includes a power conversion unit 10, a current sampling circuit 11, and a signal comparison unit 16. The power conversion unit 10 is used to perform power conversion based on an input power supply P and generate an output current. The power conversion unit 10 has a power output terminal, and the power conversion unit 10 outputs the output current from the power output terminal. The current sampling circuit 11 is electrically connected to the power output terminal of the power conversion unit 10 to sample the output current. A transient change, and based on this, an output voltage difference signal that reflects the amplitude of the transient change. The signal comparison unit 16 is electrically connected to the current sampling circuit 11 to receive the output voltage difference signal. and with a preset voltage value Compare output voltage difference signals When the output voltage difference signal Greater than or equal to the preset voltage value At that time, the signal comparison unit 16 generates a dynamic compensation command. In this embodiment of the invention, the input power source P includes mains power, a power outlet, or other power sources.

[0022] Please see Figure 1B , it is Figure 1A A block diagram showing the current sampling circuit 11 in power supply 1 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, power supply 1 includes a power conversion unit 10, a current sampling circuit 11, and a signal comparison unit 16, while 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 power supply P and converts the input signal of power supply P into an output current. The power conversion unit 10 has a power output terminal, and the power conversion unit 10 outputs the output current from the power output terminal. The input signal of power supply P includes either alternating current or direct current. An output capacitor is provided at the power output terminal of power conversion unit 10. The voltage signal conversion unit 12 is electrically connected to the power output terminal and the load terminal of the power conversion unit 10, converting the output current. For output voltage signal A load resistor is set at the load end. 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, amplifying the output voltage signal. To generate an amplified output voltage signal The voltage signal processing unit 14 is electrically connected to the voltage signal amplification unit 13, and delays and amplifies the output voltage signal. The change in voltage to generate a lagging output voltage signal That is, the voltage signal is delayed and amplified by the voltage signal processing unit 14 to output the voltage signal. The change in causes the output voltage signal to lag behind. The phase change lags behind the amplified output voltage signal. 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 receives, compares, amplifies, and outputs the voltage signal. and the lagging output voltage signal To generate an output voltage difference signal The signal comparison unit 16 is electrically connected to the signal difference unit 15 and receives the output voltage difference signal. and with a preset voltage value Compare output voltage difference signals When the output voltage difference signal Greater than or equal to the preset voltage value At that time, the signal comparison unit 16 generates a dynamic compensation command. .

[0023] Please see Figure 1C , it is Figure 1B A circuit diagram of a power supply block diagram. In this embodiment of the invention, the voltage signal conversion unit 12 includes a shunt resistor. Alternatively, a Hall sensor may be used. 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, or a digital filter to filter and amplify the output voltage signal. To generate a lagging output voltage signal Digital filters amplify output voltage signals through filtering. To generate a lagging output voltage signal The steady-state average value. Signal difference unit 15 compares and amplifies the output voltage signal. and lagging output voltage signal The steady-state average value is used to generate the output voltage difference signal. The signal difference unit 15 includes a differential amplifier, an analog comparator, or a digital comparator. The signal comparison unit 16 includes an analog comparator, a Schmitt hysteresis circuit, or a digital comparator.

[0024] In this embodiment of the invention, the voltage signal processing unit 14 includes a storage unit for storing and averaging the output voltage signal. Several amplified output voltage values ​​are used to generate a lagging output voltage signal based on these several amplified output voltage values. The lagging output voltage average value. Signal difference unit 15 compares and amplifies the output voltage signal. and lagging output voltage signal The lagging output voltage average value is used to generate the output voltage difference signal. In this embodiment of the invention, the storage unit is a temporary register, and stores several amplified output voltage values ​​at a preset sampling frequency. For example, storing several amplified output voltage values ​​at a preset sampling frequency per second. .

[0025] Please see Figure 2 This is a schematic diagram of the waveform changes in dynamic load response. For example... Figure 2 As shown, the amplified output voltage signal Without the voltage signal processing unit 14 delaying the signal, when a large amount of load is withdrawn from the load side, the dynamic load response changes drastically. However, after amplifying the output voltage signal... Delaying and amplifying the output voltage signal using filtering or averaging methods After the signal changes, the output voltage signal can be amplified. The change is relatively gradual, resulting in a slower-changing, lagging output voltage signal. Furthermore, through the aforementioned storage unit, the amplified output voltage signal can be captured and stored at different time points T1, T2, and T3. and lagging output voltage signal The values ​​are calculated, and the differences in their signal changes are compared. Taking the first time point T1 and the second time point T2 as examples, due to the amplified output voltage signal... and lagging output voltage signal The difference in the amount of change is the same, that is, the amplified output voltage signal. and lagging output voltage signal There is no difference in the amount of change between them; therefore, the output voltage difference signal generated by the signal difference unit 15 is... It is not greater than or equal to the preset voltage value. At the third time point T3, due to the amplified output voltage signal... and lagging output voltage signal The increase in the amount of difference change results in the output voltage difference signal generated by the signal difference unit 15. The signal comparison unit 16 compares voltage values ​​that are greater than or equal to a preset voltage value. At this time, it can be determined that a large amount of load is being withdrawn from the load side. Therefore, the signal comparison unit 16 generates a dynamic compensation command. Implement a dynamic compensation mechanism.

[0026] As described above, after storing several amplified output voltage values ​​in the storage unit, the signal difference unit 15 compares at least one amplified output voltage value with the lagging output voltage signal among the several amplified output voltage values. To generate at least one output voltage difference signal The signal comparison unit 16 receives at least one output voltage difference signal. and with a preset voltage value Compare at least one output voltage difference signal When at least one output voltage difference signal Greater than or equal to the preset voltage value At that time, the signal comparison unit 16 generates at least one dynamic compensation command. Furthermore, when the signal comparison unit 16 generates multiple dynamic compensation commands based on the results of multiple comparisons, In such cases, multiple compensations can be performed in a segmented manner. For example, when signal comparison unit 16 generates three dynamic compensation commands... Then, it can be divided into 3 stages to output 3 dynamic compensation instructions. Compensation will be provided.

[0027] Please see Figure 3 This is a flowchart illustrating the steps of the power supply control method of the present invention. The power supply control method includes the following steps: In step S11, a power conversion unit performs power conversion based on an input power supply and generates an output current. In step S12, a transient change in the output current is sampled by a current sampling circuit, and an output voltage difference signal reflecting the amplitude of the transient change is generated accordingly. In step S13, the output voltage difference signal is received by a signal comparison unit and compared with a preset voltage value. In step S13, when the output voltage difference signal is greater than or equal to the preset voltage value, step S14 is executed, and the signal comparison unit generates a dynamic compensation command. In step S13, if the output voltage difference signal is not greater than or equal to the preset voltage value, return to step S12.

[0028] Please see Figure 4A and Figure 4B , Figure 4A To simulate the design schematic using a simulated circuit, Figure 4B This is a schematic diagram of the signal simulation line result. In this embodiment of the invention, the use of analog circuits is not limited to; digital control can also be used, such as... Figure 1C The concept was completed. (At) Figure 4A The simulation sets the load to reach 200A with a slope of 2.5A / µs, and triggers dynamic compensation control mode when a negative change of 50A occurs. Figure 4B The solid line shows that a dynamic response is triggered approximately 20 μs after a load change. It has a significantly faster response time than the traditional voltage feedback control method (generally it takes at least 60μs to determine that the load has changed).

[0029] It should be noted here that, Figure 4A and Figure 4B The simulation results mainly demonstrate that the power supply using the embodiments of this application has a significantly faster response time compared to the traditional voltage detection control method, resulting in more stable output current control of the power supply. Figure 4A and Figure 4B The resistors R1~R13, capacitors C1~C4, and voltages V1~V5 mentioned are... , Current The specific time values ​​are merely illustrative examples within the framework of one embodiment of this application, and this application is not limited thereto.

[0030] In summary, the power supply and control method of the present invention use a current feedback signal as a trigger control command. That is, by detecting the voltage response of dynamic current, and then triggering and generating a compensation control command to the converter in advance when a rapid change in the output load current is detected during the dynamic response, so as to compensate the output voltage to the regulated voltage range before it exceeds the voltage regulation range.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A power supply, characterized by, The power conversion unit includes a power output terminal, and the power conversion unit 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, samples a transient change of the output current, and generates an output voltage difference signal corresponding to the amplitude of the transient change. The signal comparison unit is electrically connected to the current sampling circuit, receives the output voltage difference signal, and compares the output voltage difference signal with a preset voltage value. When the output voltage difference signal is greater than or equal to the preset voltage value, the signal comparison unit generates a dynamic compensation instruction. The current sampling circuit includes:

2. The power supply of claim 1, wherein, The 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. The voltage signal amplification unit is electrically connected to the voltage signal conversion unit, amplifies the output voltage signal, and generates an amplified output voltage signal. The voltage signal processing unit is electrically connected to the voltage signal amplification unit, delays the change of the amplified output voltage signal, and generates a lag output voltage signal. The signal difference unit is electrically connected to the voltage signal amplification unit and the voltage signal processing unit, receives and compares the amplified output voltage signal and the lag output voltage signal, and generates the output voltage difference signal provided to the signal comparison unit. The voltage signal conversion unit includes a shunt resistor or a Hall sensing element. The voltage signal amplification unit includes a differential amplifier or a non-inverting amplifier.

3. The power supply of claim 2, wherein The voltage signal processing unit includes a low-pass filter, an active filter, a resistor-capacitor filter, or a digital filter, which filters the amplified output voltage signal to generate the lag output voltage signal.

4. The power supply of claim 2, wherein The digital filter filters the amplified output voltage signal to generate a steady-state average value of the lag output voltage signal.

5. The power supply of claim 2, wherein, The signal difference unit compares the steady-state average values of the amplified output voltage signal and the lag output voltage signal to generate the output voltage difference signal.

6. The power supply of claim 5, wherein, The signal difference unit includes a differential amplifier, an analog comparator, or a digital comparator. The signal comparison unit includes an analog comparator, a Schmitt hysteresis circuit, or a digital comparator.

7. The power supply of claim 2, wherein The voltage signal processing unit includes a storage unit that stores and averages a plurality of amplified output voltage values of the amplified output voltage signal to generate a lag output voltage average value of the lag output voltage signal based on the plurality of amplified output voltage values.

8. The power supply of claim 1, wherein, The signal difference unit receives and compares the lag output voltage average value of the amplified output voltage signal and the lag output voltage signal to generate the output voltage difference signal.

9. The power supply of claim 2, wherein, The storage unit stores the plurality of amplified output voltage values at a preset sampling frequency. The power conversion unit includes a power output terminal, and the power conversion unit outputs the output current from the power output terminal.

10. The power supply of claim 9, wherein, The current sampling circuit is electrically connected to the power output terminal of the power conversion unit, samples a transient change of the output current, and generates an output voltage difference signal corresponding to the amplitude of the transient change.

11. A control method of a power supply, characterized by, ​ ​ ​ And The output voltage difference signal is received by a signal comparison unit, and compared with a preset voltage value; When the output voltage difference signal is greater than or equal to the preset voltage value, the signal comparison unit generates a dynamic compensation instruction.

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