Power supply control system

Abstract

This invention provides a power supply control system for supplying power to a load and includes a first power supply device, a second power supply device, and a buck converter. The first power supply device has a first output voltage and outputs a first output current to the load. The second power supply device has a second output voltage and outputs a second output current to the load. The buck converter selectively connects to either the first or second power supply device, and then connects in parallel with the unconnected power supply device and the load. Based on the first and second output voltages, the buck converter selectively connects to the power supply device with the higher output voltage, and controls the converter's output voltage to match the voltage of the other power supply device, thereby connecting the two power supply devices in parallel and outputting current to the load. The power supply control system provided by this invention can improve the endurance and power supply efficiency of the power supply device.

Description

Technical Field

[0001] This invention relates to a control system, specifically a power supply control system capable of balancing the voltages of multiple power supply devices. Background Technology

[0002] In recent years, with the rapid development of technology and the increasing awareness of green energy, electric vehicles, which use electric power to replace gasoline power, have gradually emerged. The power supply device for electric vehicles is a battery, and electric vehicles can contain several batteries to maintain their range.

[0003] Generally, electric vehicles require significant kinetic energy for starting, acceleration, and hill climbing. Therefore, their power supply systems typically connect several batteries in parallel to provide sufficient current and energy. However, because each battery has slightly different charging / discharging characteristics and voltage differences, directly connecting them in parallel can cause internal circulating currents that generate heat, reducing the vehicle's range. To address this overheating issue, electric vehicles usually include a battery control switch connecting the two battery banks to control their output and voltage separately.

[0004] In existing battery control methods, when one battery in the power supply system has a higher voltage, the battery control switch will turn on the higher-voltage battery and turn off the lower-voltage battery, allowing the higher-voltage battery to supply power alone, thereby lowering its voltage. Only when the voltage difference among all the batteries in the power supply system is small will the battery control switch turn on all batteries to provide power in parallel. However, when the higher-voltage battery supplies power alone, the battery may experience excessive current output, reducing its lifespan, thus decreasing range and increasing cost. Furthermore, the battery control switch only has a switching function. When all batteries are turned on, the battery control switch cannot control the battery output current. Therefore, batteries may have internal impedance differences due to their different characteristics, and the low-impedance battery will continuously supply power with a high current, making it impossible to distribute the output current among the batteries. In addition, when the battery control switch turns the batteries on or off, the power supply system is prone to surge currents, which may damage other electronic components of the electric vehicle, causing malfunctions or reduced efficiency. Summary of the Invention

[0005] In view of the problems in the prior art, the purpose of this invention is to provide a power supply control system to solve the problems in the prior art.

[0006] This invention provides a power supply control system for supplying power to a load and includes a first power supply device, a second power supply device, and a buck converter. The first power supply device has a first output voltage and is used to output a first output current to the load. The second power supply device has a second output voltage and is used to output a second output current to the load. The buck converter selectively connects the first power supply device, the second power supply device, and the load in parallel. The buck converter is used to selectively adjust the output voltages of the first and second power supply devices according to the first output voltage, the second output voltage, and the load voltage of the load. When the first output voltage is greater than the second output voltage or the second output voltage is greater than the first output voltage, the buck converter controls the first and second output voltages to balance each other.

[0007] The power supply control system of the present invention further includes a controller connected to a buck converter, and the buck converter includes a first adjustment switch, a second adjustment switch, and a third adjustment switch. The controller is used to control the first adjustment switch, the second adjustment switch, and the third adjustment switch of the buck converter to adjust the output voltage of at least one of the first power supply device and the second power supply device.

[0008] Among them, the second adjustment switch and the third adjustment switch are one of the transistor and the diode.

[0009] The controller is a pulse-width modulation controller (PWM controller).

[0010] In one specific embodiment, the buck converter is located between the first power supply device and the second power supply device, and the second power supply device is located between the buck converter and the load. When the first output voltage and the second output voltage are the same, the controller controls the first adjustment switch to be fully turned on, so that the first power supply device, the second power supply device, and the load are connected in parallel.

[0011] Specifically, when the first output voltage of the first power supply device is less than the load voltage of the load, the controller controls the first adjustment switch and the third adjustment switch to open.

[0012] In one specific embodiment, the power supply control system of the present invention further includes a first circuit, a second circuit, a third circuit, and a fourth circuit, and a first switch, a second switch, a third switch, and a fourth switch respectively disposed on the first circuit, the second circuit, the third circuit, and the fourth circuit, and includes a switchgear connecting and controlling the first switch, the second switch, the third switch, and the fourth switch. A step-down converter is located between the first power supply device and the load, and between the second power supply device and the load. The first circuit connects the first power supply device, the step-down converter, and the load; the second circuit connects the second power supply device and the load; the third circuit connects the first power supply device and the load; and the fourth circuit connects the second power supply device, the step-down converter, and the load.

[0013] When the first output voltage is greater than the second output voltage, the switch controls the first switch and the second switch to be turned on, so that the first power supply device outputs the first output current through the first circuit, and the second power supply device outputs the second output current through the second circuit.

[0014] When the second output voltage is greater than the first output voltage, the switch controls the third switch and the third switch is turned on, so that the first power supply device outputs the first output current through the third circuit, and the second power supply device outputs the second output current through the fourth circuit.

[0015] When the first output voltage equals the second output voltage, the switch controls the second switch and the third switch to be turned on, so that the first power supply device outputs the first output current through the third circuit, and the second power supply device outputs the second output current through the second circuit.

[0016] The power supply control system provided by this invention has the following advantages:

[0017] The power supply control system of the invention can convert power supply devices with different voltages into the same output voltage through a controller and a step-down converter, thereby avoiding backflow power loss caused by voltage differences between power supply devices and improving battery life. Furthermore, the power supply control system of the invention can also operate power supply devices with the same voltage in parallel through the controller and step-down converter, thereby increasing power supply capacity. In addition, the power supply control system of the invention can also switch different circuits through a switch and a step-down converter to control and balance the output voltage of multiple power supply devices, thereby improving battery life and power supply efficiency. Attached Figure Description

[0018] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0019] Figure 1 This is a functional block diagram of a power supply control system according to a specific embodiment of the present invention.

[0020] Figure 2 yes Figure 1 The circuit diagram of the power supply control system in a specific embodiment is shown.

[0021] Figure 3 This is a circuit diagram of a power supply control system according to a specific embodiment of the present invention.

[0022] Figure 4 This is a functional block diagram of a power supply control system according to another specific embodiment of the present invention.

[0023] Figure 5 yes Figure 4 The circuit diagram of the power supply control system in a specific embodiment is shown.

[0024] Figure label:

[0025] 1, 2, 3: Power supply control system; 8: Load

[0026] 11, 21, 31: First power supply device P1: First circuit

[0027] 12, 22, 32: Second power supply device P2: Second circuit

[0028] 13, 23, 33: Buck converter; P3: Third circuit

[0029] 131, 231, 331: First adjustment switch; P4: Fourth circuit

[0030] 132, 232, 332: Second adjustment switch; S1: First switch

[0031] 133, 233, 333: Inductor; S2: Second switch

[0032] 134, 234, 334: Capacitors; S3: Third switch

[0033] 135, 235: Third adjustment switch; S4: Fourth switch

[0034] 14, 24, 34: Controller Detailed Implementation

[0035] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted. The words “or” and “or” in the specification may mean “and” or “or”.

[0036] To make the advantages, spirit, and features of the present invention more easily and clearly understood, detailed descriptions and discussions will follow with reference to specific embodiments and the accompanying drawings. It is important to note that these specific embodiments are merely representative examples of the present invention, and the specific methods, apparatuses, conditions, materials, etc., exemplified are not intended to limit the present invention or the corresponding specific embodiments. Furthermore, the devices in the figures are only used to illustrate their relative positions and are not drawn to scale; this is to be understood beforehand.

[0037] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "up," "down," "front," "back," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate that the device or component described must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0038] Please see Figure 1 and Figure 2 . Figure 1 This is a functional block diagram of a power supply control system 1 according to a specific embodiment of the present invention. Figure 2 yes Figure 1 A circuit diagram of a power supply control system 1 according to a specific embodiment. (See diagram below.) Figure 1 As shown, in this specific embodiment, the power supply control system 1 includes a first power supply device 11, a second power supply device 12, and a buck converter 13, and the power supply control system 1 is used to supply power to the load 8. The first power supply device 11 has a first output voltage and is used to output a first output current to the load 8. The second power supply device 12 has a second output voltage and is used to output a second output current to the load 8. The buck converter 13 selectively connects the first power supply device 11, the second power supply device 12, and the load 8 in parallel. Furthermore, the buck converter 13 is used to selectively adjust the output voltages of the first power supply device 11 and the second power supply device 12 according to the first output voltage of the first power supply device 11, the second output voltage of the second power supply device 12, and the load voltage of the load 8, so that the first output voltage and the second output voltage are balanced.

[0039] In practice, the power supply control system 1 of the present invention can be applied to electric vehicles. The first power supply device 11 and the second power supply device 12 can be batteries, the step-down converter 13 can be integrated on the main control board or the power supply module circuit board, and the load 8 can be a power device such as the motor controller of the electric vehicle. Furthermore, the circuit board of the main control board or the power supply module can be connected to the first power supply device 11, the second power supply device 12 and the load 8 to control the first power supply device 11 and the second power supply device 12 to provide electrical energy to the load 8, thereby enabling the load 8 to operate.

[0040] like Figure 1and Figure 2 As shown, in this specific embodiment, the buck converter 13 is located between the first power supply device 11 and the second power supply device 12, and the second power supply device 12 is located between the first power supply device 11 and the load 8. The buck converter 13 is used to adjust the output voltage of the first power supply device 11 according to the first output voltage of the first power supply device 11, the second output voltage of the second power supply device 12, and the load voltage of the load 8. Further, the buck converter 13 includes a first adjustment switch 131, a second adjustment switch 132, and a third adjustment switch 135, and the power supply control system 1 further includes a controller 14 connected to the first adjustment switch 131, the second adjustment switch 132, and the third adjustment switch 135 of the buck converter 13. The controller 14 is used to control the on and off of the first adjustment switch 131, the second adjustment switch 132, and the third adjustment switch 135 of the buck converter to adjust the output voltage of the first power supply device 11. In practice, the first adjustment switch 131, the second adjustment switch 132, and the third adjustment switch 135 can be transistors. More specifically, the first adjustment switch 131 and the second adjustment switch 132 can be metal-oxide-semiconductor field-effect transistors (MOSFETs). The controller 14 can be a pulse-width modulation controller (PWM controller), and the controller 14 can be integrated onto the main control board or the power supply module's circuit board.

[0041] In practice, the power supply control system 1 may further include a voltage detector (not shown) connected to the first power supply device 11, the second power supply device 12, the load 8, and the controller 14. In practice, the voltage detector may also be integrated onto the main control board or the circuit board of the power supply module, and used to detect the first output voltage of the first power supply device 11, the second output voltage of the second power supply device 12, and the load voltage of the load 8. Therefore, the controller 14 can control the first adjustment switch 131 based on the first output voltage and the second output voltage measured by the voltage detector.

[0042] like Figure 2As shown, when the first output voltage of the first power supply device 11 is greater than the second output voltage of the second power supply device 12, the controller 14 can control the first adjustment switch 131, the second adjustment switch 132, and the third adjustment switch 135 of the buck converter 13 to adjust the output voltage of the buck converter 13. In practice, when the controller 14 controls the first adjustment switch 131 and the third adjustment switch 135 to be turned on and controls the second adjustment switch 132 to be turned off, the first power supply device 11 can output a first output current to the buck converter 13. At this time, the buck converter 13 can increase the first output current through the inductor 133 and the capacitor 134 using the power from the power supply device 11, thereby reducing the first output voltage of the first power supply device 11. Furthermore, the controller 14 can control the duty cycle of the first adjustment switch 131 to control the flow rate of the first output current, thereby adjusting the first output voltage of the first power supply device 11 to balance the first output voltage and the second output voltage. Therefore, the power supply control system of the present invention can convert power supply devices with different voltages into the same output voltage through the controller and the step-down converter, so as to avoid backflow caused by voltage differences between power supply devices, resulting in power loss and temperature rise, thereby improving the endurance.

[0043] When the first output voltage of the first power supply device 11 and the second output voltage of the second power supply device 12 are the same, the controller 14 controls the first adjustment switch 131 to be fully turned on, so that the first power supply device 11, the second power supply device 12, and the load 8 are connected in parallel. In practice, when the first output voltage and the second output voltage are the same, the controller 14 can control the first adjustment switch 131 and the third adjustment switch 135 to be fully turned on, so that the first output current of the first power supply device 11 can pass completely through the buck converter 13 and flow to the inductor 133 and the capacitor 134 of the buck converter 13. Furthermore, since the voltages of the first power supply device 11 and the second power supply device 12 are similar, when the inductor 133 is saturated due to a large current, the inductor 133 will be like a short circuit, so that the output current of the first power supply device 11 is connected in parallel with the inductor 133, the second power supply device 12, and the load 8 via the switch 131. In practice, when an electric vehicle is starting, accelerating, or climbing, the first power supply device 11 and the second power supply device 12 can simultaneously supply power to the load 8 to increase the output power. Therefore, the power supply control system of the present invention can also operate power supply devices with the same voltage in parallel through a controller and a step-down converter, thereby improving the power supply capacity and efficiency.

[0044] Furthermore, when the first output voltage of the first power supply device 11 is less than the load voltage of the load 8, the controller 14 controls the first adjustment switch 131, the second adjustment switch 132, and the third adjustment switch 135 to open. In practice, when the first output voltage of the first power supply device 11 is less than the output voltage of the second power supply device 12 and the load 8, it indicates that the first power supply device 11 cannot provide the first output current to the load 8. Therefore, the controller 14 controls the third adjustment switch 135 to open. At this time, only the second power supply device 12 provides current to the load 8. However, once the output voltage of the second power supply device 12 drops to the same level as or below the output voltage of the first power supply device 11 due to the large output current, the buck converter 13 will restart, so that the first power supply device 11 and the second power supply device 12 are connected in parallel to supply power.

[0045] In one specific embodiment, the controller 14 can control the on-duty period of the first adjustment switch 131, while during the off period of the first adjustment switch 131, the controller 14 controls the second adjustment switch 132 to be turned on. In practice, when the inductor 133 and capacitor 134 of the buck converter 13 provide current to the load 8, the controller 14 can control the second adjustment switch 231 to be turned on to provide a discharge circuit for the inductor 133, releasing the energy stored on the inductor 133 to the capacitor 134 and the load 8, so as to avoid the inductor 133 induced by surge voltage and damage to the circuit.

[0046] The second adjustment switch of the buck converter is not limited to the transistor in the aforementioned specific embodiment; the second adjustment switch can also be of other forms. Please refer to [link to relevant documentation]. Figure 3 . Figure 3 This is a circuit diagram of a power supply control system 2 according to a specific embodiment of the present invention. Figure 3 As shown, in this specific embodiment, the second adjustment switch 232 and the third adjustment switch 235 are diodes, and the controller 24 can control the first adjustment switch 231 of the buck converter 23 to adjust the output voltage of the first power supply device 21. In practice, when the first output voltage of the first power supply device 21 is greater than the second output voltage of the second power supply device 22, the controller 24 controls the first adjustment switch 231 to turn on. At this time, the second adjustment switch 232 is reverse biased, while the third adjustment switch 235 is forward biased. Therefore, the first output current of the first power supply device 21 will not flow to the second adjustment switch 232 but will flow through the inductor 233, the third adjustment switch 235, the capacitor 234, and the load 8. The voltage difference between the first power supply device 21 and the second power supply device 22 is borne by the inductor 233, making the output voltage of the buck converter 23 the same as that of the second power supply device 22. When the first output voltage of the first power supply device 21 is less than the voltage of the second power supply device 22 and the load 8, the third adjustment switch is cut off due to reverse bias, and the current of the second power supply device 22 will not flow back to the first power supply device 21 to generate circulating current.

[0047] The power supply control system of the present invention can be in other forms besides the specific embodiments described above. Please refer to [link / reference]. Figure 4 and Figure 5 . Figure 4 This is a functional block diagram of the power supply control system 3 according to another specific embodiment of the present invention. Figure 5 yes Figure 4 The circuit diagram of the power supply control system 3 in a specific embodiment is shown below. Figure 4 and Figure 5 As shown, the difference between this specific embodiment and the previous specific embodiments is that both the first power supply device 31 and the second power supply device 32 are connected to the buck converter 33. That is, the buck converter 33 is located between the first power supply device 31 and the load 8, and also between the second power supply device 32 and the load 8. Therefore, the first power supply device 31 and the second power supply device 32 can output current to the load 8 through the buck converter 33. Please note that the functions of the first adjustment switch 331, the second adjustment switch 332, the inductor 333, the capacitor 334, and the controller 34 of the buck converter 33 in this specific embodiment are roughly the same as the functions of the corresponding components in the previous embodiments, and will not be described again here.

[0048] like Figure 5 As shown, in this specific embodiment, the power supply control system 3 includes a first circuit P1, a second circuit P2, a third circuit P3, and a fourth circuit P4. The first circuit P1 connects to the first power supply device 31, the step-down converter 33, and the load 8; the second circuit P2 connects to the second power supply device 32 and the load 8; the third circuit P3 connects to the first power supply device 31 and the load 8; and the fourth circuit P4 connects to the second power supply device 32, the step-down converter 33, and the load 8. Further, the power supply control system 3 includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4, respectively disposed on the first circuit P1, the second circuit P2, the third circuit P3, and the fourth circuit P4. The power supply control system 3 can adjust the output modes of the first power supply device 31 and the second power supply device 32 by switching the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4. In practice, the power supply control system 3 may further include a switch (not shown) connected to and controlling the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4. The switch can be integrated onto the main control board or the power supply module's circuit board, and can also be connected to a voltage detector.

[0049] In practice, when the first output voltage of the first power supply device 31 is greater than the second output voltage of the second power supply device 32, the switch controls the first switch S1 and the second switch S2 to be turned on, and controls the third switch S3 and the fourth switch S4 to be turned off. At this time, the first power supply device 31 outputs a first output current through the first circuit P1, and the second power supply device 32 outputs a second output current through the second circuit P2. When the first output current of the first power supply device 31 flows through the first circuit P1, the first power supply device 31 can adjust its first output voltage through the buck converter 33 to balance the first output voltage of the first power supply device 31 with the second output voltage of the second power supply device 32. Furthermore, the first power supply device 31, the buck converter 33, the second power supply device 32, and the load 8 are connected in parallel. Therefore, the first power supply device 31 and the second power supply device 32 can simultaneously output current to the load 8 under the same output voltage.

[0050] When the second output voltage of the second power supply device 32 is greater than the first output voltage of the first power supply device 31, the switch controls the third switch S3 and the fourth switch S4 to be turned on, and controls the first switch S1 and the second switch S2 to be turned off. At this time, the first power supply device 31 outputs the first output current through the third circuit P3, and the second power supply device 32 outputs the second output current through the fourth circuit P4. When the second output current of the second power supply device 32 flows through the fourth circuit P4, the second power supply device 32 can adjust the second output voltage through the buck converter 33 to balance the first output voltage of the first power supply device 31 and the second output voltage of the second power supply device 32. Furthermore, the first power supply device 31, the second power supply device 32, the buck converter 33, and the load 8 are connected in parallel. Therefore, the first power supply device 31 and the second power supply device 32 can simultaneously output current to the load 8 under the condition of the same output voltage.

[0051] When the first output voltage of the first power supply device 31 is equal to the second output voltage of the second power supply device 32, it means that neither the first power supply device 31 nor the second power supply device 32 needs to adjust their first and second output voltages. At this time, the switch controls the second switch S2 and the third switch S3 to be turned on, and controls the first switch S1 and the fourth switch S4 to be turned off. Therefore, the first power supply device 31 outputs the first output current through the third circuit P3, and the second power supply device 32 outputs the second output current through the second circuit P2. The first power supply device 31, the second power supply device 32, and the load 8 are connected in parallel, and the first power supply device 31 and the second power supply device 32 can simultaneously output current to the load 8.

[0052] In practice, when the electric vehicle is changing its battery and running, the switch can switch between the first output voltage of the first power supply device 31 and the second output voltage of the second power supply device 32 as measured by the switch, so as to maintain the first and second output voltages in a balanced state. Furthermore, when the voltages of the first and second power supply devices are close, when the electric vehicle is accelerating or climbing, the switch can also control the first power supply device 31 and the second power supply device 32 to directly supply power to the load 8 via the third circuit P3 and the second circuit P2, respectively, to increase the output power. Further, when the electric vehicle is going downhill, the switch can also switch to the second circuit P2 and the third circuit P3, so that the load 8 can control the first power supply device 31 and the second power supply device 32 to recharge current through the step-down converter 33. Therefore, the power supply control system of the present invention can also control the output voltage of multiple power supply devices by switching switches, thereby improving range and power supply efficiency.

[0053] In summary, the power supply control system of the present invention can convert power supply devices with different voltages into the same output voltage through a controller and a step-down converter, thereby avoiding circulating currents caused by voltage differences between power supply devices, resulting in power loss and temperature rise, and thus improving battery life. Furthermore, the power supply control system of the present invention can also operate power supply devices with the same voltage in parallel through the controller and step-down converter, thereby improving power supply efficiency.

[0054] The detailed description of the preferred embodiments above is intended to more clearly illustrate the features and spirit of the present invention, and is not intended to limit the scope of the invention to the preferred embodiments disclosed above. Rather, the aim is to cover various modifications and equivalent arrangements within the scope of the patent claims made by the present invention. Therefore, the scope of the patent claims made by the present invention should be interpreted in the broadest possible sense based on the foregoing description, so as to cover all possible modifications and equivalent arrangements that fall within the protection scope of the present invention.

Claims

1. A power supply control system for supplying power to a load, characterized in that, The power supply control system includes: A first power supply device having a first output voltage and for outputting a first output current to the load; A second power supply device having a second output voltage and for outputting a second output current to the load; and A buck converter, the buck converter being located between the first power supply and the load, and also located between the second power supply and the load; and Switch; The power supply control system further includes: A first circuit is connected between the first power supply device and the input terminal of the buck converter; A second circuit is connected between the first power supply device and the load; A third circuit is connected between the second power supply device and the load; The fourth circuit is connected between the second power supply device and the input terminal of the buck converter; A first switch is provided on the first circuit; The second switch is installed on the second circuit; A third switch is provided on the third circuit; A fourth switch is provided on the fourth circuit; The output terminal of the buck converter is connected to the load. The switch connects to and controls the on and off states of the first switch, the second switch, the third switch, and the fourth switch; The switch is configured to: When the first output voltage is greater than the second output voltage, the first switch and the second switch are turned on, and the third switch and the fourth switch are turned off, so that the first power supply device supplies power to the load through the first circuit and the step-down converter, and the second power supply device supplies power to the load through the second circuit. When the second output voltage is greater than the first output voltage, the third switch and the fourth switch are turned on, and the first switch and the second switch are turned off, so that the second power supply device supplies power to the load through the fourth circuit and the step-down converter, and the first power supply device supplies power to the load through the third circuit. In the configuration where the first switch and the second switch are turned on, or the third switch and the fourth switch are turned on, the buck converter adjusts the output voltage of the higher voltage power supply device according to the first output voltage and the second output voltage to balance the output voltage of the lower voltage power supply device, so that the first power supply device and the second power supply device can supply power to the load in parallel.

2. The power supply control system according to claim 1, characterized in that, It also includes a controller, which is a pulse width modulation controller.

3. The power supply control system according to claim 1, characterized in that, When the first output voltage is equal to the second output voltage, the switch controls the second switch and the third switch to be turned on, so that the first power supply device outputs the first output current through the third circuit, and the second power supply device outputs the second output current through the second circuit.

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