Low-ripple high-power hybrid power supply

Abstract

An input power supply is respectively connected with a bidirectional direct-current power supply and a direct-current switching power supply, the bidirectional direct-current power supply is respectively connected with a user load and a linear voltage-stabilized power supply, the output end of the direct-current switching power supply is connected with the linear voltage-stabilized power supply, and the output end of the linear voltage-stabilized power supply is connected with the user load. The linear voltage-stabilized power supply comprises an operational amplifier and a field-effect tube, the positive-phase input end of the operational amplifier is connected with external reference voltage, the drain electrode of the field-effect tube is connected with the direct-current switching power supply, the grid electrode of the field-effect tube is connected with the vertex angle output end of the operational amplifier, and the source electrode of the field-effect tube is connected with a user load. The output end of the linear voltage-stabilized power supply is connected with a user load, the output end of the bidirectional direct-current power supply is connected with the inverted input end of an operational amplifier of the linear voltage-stabilized power supply, the bidirectional direct-current power supply is connected with the user load, the output end of the direct-current switching power supply is connected with the drain electrode of a field-effect tube of the linear voltage-stabilized power supply, and the direct-current switching power supply is grounded.

Description

Technical Field

[0001] The present invention relates to the technical field of high-performance intelligent instrumentation, and more specifically, to a low-ripple high-power hybrid power supply. Background Art

[0002] Traditional switching power supplies can provide high power output. Switching power supplies adjust the output voltage or current through high-frequency switching. This process introduces rapidly changing current and voltage, resulting in ripples at the output. Although ripples can be reduced by adding filtering components, this will increase cost, volume and weight, and have limited effect on reducing electromagnetic interference (EMI).

[0003] On the other hand, linear power supplies are known for their extremely low output ripple and are suitable for applications that require high precision and stability. However, the way linear power supplies work is to dissipate a lot of energy in the adjustment element to accurately control the output voltage, which is not only inefficient, but also causes significant heating problems when handling high power. Therefore, when faced with high power requirements, linear power supplies often seem to be unable to cope with high power demands due to excessive power consumption and difficulty in heat dissipation.

[0004] As a solution to the above problems, multi-phase interleaving technology attempts to minimize output ripple while maintaining high-efficiency and high-power output. This technology disperses the load current, smoothes the output current waveform, reduces the total output ripple amplitude, and reduces the pressure on the input filter by running multiple independent switching converters in parallel and making them work in different phases. Nevertheless, multi-phase interleaving technology still cannot completely eliminate output ripple, especially in extreme high-power application scenarios. It is still a challenge to achieve ideal low ripple performance at the same time.

[0005] Therefore, when pursuing high power output, existing power supply technology often has to sacrifice output ripple performance to a certain extent, and vice versa. This trade-off reflects a core contradiction in current power supply design: it is difficult to achieve efficient high power output and extremely low output ripple in the same power supply system. Summary of the invention

[0006] In order to solve the problem of achieving both efficient high-power output and extremely low output ripple, the present invention provides a low-ripple high-power hybrid power supply.

[0007] The technical solution of the present invention is as follows:

[0008] A low-ripple high-power hybrid power supply includes a bidirectional DC power supply, a DC switching power supply and a linear voltage-regulated power supply. The input power supply is connected to the bidirectional DC power supply and the DC switching power supply respectively.

[0009] The bidirectional DC power supply is connected to the user load and the linear regulated power supply respectively, the output end of the DC switching power supply is connected to the linear regulated power supply, and the output end of the linear regulated power supply is connected to the user load.

[0010] The linear regulated power supply includes an operational amplifier and a field effect transistor.

[0011] The non-inverting input terminal of the operational amplifier is connected to the external reference voltage, the drain of the field effect tube is connected to the DC switching power supply, the gate of the field effect tube is connected to the top corner output terminal of the operational amplifier, the source of the field effect tube is connected to the user load, and the output terminal of the linear voltage regulator is connected to the user load.

[0012] The output end of the bidirectional DC power supply is connected to the inverting input end of the operational amplifier of the linear voltage regulated power supply, and the bidirectional DC power supply is connected to the user load.

[0013] The output end of the DC switching power supply is connected to the drain of the field effect tube of the linear voltage-stabilized power supply, and the DC switching power supply is grounded.

[0014] In the above-mentioned low-ripple high-power hybrid power supply, when the hybrid power supply circuit works normally, the output terminal voltage of the DC switching power supply is greater than the output terminal voltage of the linear regulated power supply.

[0015] Furthermore, the factors to be considered for the voltage difference between the output voltage of the DC switching power supply and the output voltage of the linear regulated power supply include:

[0016] (1) Minimum voltage difference, based on the minimum voltage difference required for the normal operation of the linear regulated power supply;

[0017] (2) Ripple: voltage margin based on expected ripple amplitude;

[0018] (3) Dynamic load, adding additional pressure difference according to the changes in user load;

[0019] (4) Thermal management: reasonably control the thermal energy consumption of the linear regulated power supply.

[0020] Furthermore, the voltage difference between the dynamic load of the linear regulated power supply and the thermal management is a preset value, satisfying

[0021] [(output voltage of DC switching power supply - output voltage of linear regulated power supply) / output voltage of linear regulated power supply]∈[1%,5%].

[0022] In the above-mentioned low-ripple high-power hybrid power supply, when the hybrid power supply circuit works normally, the output voltage of the bidirectional DC power supply is lower than the output voltage of the linear regulated power supply, the reference voltage is lower than the output voltage of the linear regulated power supply, and the bidirectional DC power supply is in a constant current load state.

[0023] Furthermore, when the state of the DC switching power supply or the user load state causes the output voltage of the linear regulated power supply to be less than the set target value, the linear regulated power supply increases the conduction degree or suspends the regulation action, and the bidirectional DC power supply supplies power to the user load, so that the output voltage of the linear regulated power supply recovers.

[0024] Furthermore, when the DC switching power supply state or the user load state causes the output voltage of the linear regulated power supply to be higher than the set target value, the linear regulated power supply reduces the conduction degree, the bidirectional DC power supply increases the supply current to the user load, and reduces the output voltage of the linear regulated power supply.

[0025] According to the present invention of the above scheme, its beneficial effect is that the switching power supply provides high-efficiency high-power output, the linear voltage-stabilized power supply ensures low ripple and stability of the output voltage, and the bidirectional DC power supply consumes almost no power in normal state, and as a backup power supply, provides adjustment in emergency state. When the user load suddenly increases and causes the output voltage of the linear voltage-stabilized power supply to drop, the bidirectional DC power supply quickly switches to the source state, supplements the user load with additional current, and makes the output voltage of the linear voltage-stabilized power supply quickly recover to the set value. At the same time, the linear voltage-stabilized power supply continues to absorb the ripple from the DC switching power supply to ensure the output quality. When the user load suddenly decreases or other reasons cause the output voltage of the linear voltage-stabilized power supply to rise, the bidirectional DC power supply will increase the feedback current, quickly pull down the output voltage of the linear voltage-stabilized power supply, maintain the stability of the output voltage of the hybrid power supply, and protect the circuit connected to the hybrid power supply from the influence of excessive voltage. If the voltage difference between the linear voltage-stabilized power supply and the bidirectional DC power supply is too large (for example, due to a sharp change in the user load), the bidirectional DC power supply can control the linear voltage-stabilized power supply to shut down to prevent it from being damaged due to overheating or overload. Through the design of coordinated control and mutual cooperation among the three power supplies, the hybrid power supply can not only efficiently provide high-power output, ensuring that the output voltage has extremely low ripple while having high stability and smoothness, but also can quickly respond to changes in user loads, enhancing the transient response capability of the hybrid power supply, thereby improving the reliability and performance of the entire power supply system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of the hybrid power supply of the present invention. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] A low ripple high power hybrid power supply, such as Figure 1 As shown, it includes a bidirectional DC power supply, a DC switching power supply and a linear regulated power supply, the input power supply is respectively connected to the bidirectional DC power supply and the DC switching power supply, the bidirectional DC power supply is respectively connected to the user load and the linear regulated power supply, the output end of the DC switching power supply is connected to the linear regulated power supply, the output end of the linear regulated power supply is connected to the user load, the linear regulated power supply includes an operational amplifier and a field effect transistor, the non-inverting input end of the operational amplifier is connected to an external reference voltage, the drain of the field effect transistor is connected to the DC switching power supply, the gate of the field effect transistor is connected to the top corner output end of the operational amplifier, the source of the field effect transistor is connected to the user load, the output end of the linear regulated power supply is connected to the user load, the output end of the bidirectional DC power supply is connected to the inverting input end of the operational amplifier of the linear regulated power supply, the bidirectional DC power supply is connected to the user load, the output end of the DC switching power supply is connected to the drain of the field effect transistor of the linear regulated power supply, and the DC switching power supply is grounded.

[0030] When the hybrid power supply circuit operates normally, the output terminal voltage of the DC switching power supply is greater than the output terminal voltage of the linear regulated power supply.

[0031] Factors to consider for the voltage difference between the output voltage of a DC switching power supply and the output voltage of a linear regulated power supply include:

[0032] (1) Minimum voltage difference, based on the minimum voltage difference required for the normal operation of the linear regulated power supply;

[0033] (2) Ripple: voltage margin based on expected ripple amplitude;

[0034] (3) Dynamic load, adding additional pressure difference according to the changes in user load;

[0035] (4) Thermal management: reasonably control the thermal energy consumption of the linear regulated power supply.

[0036] The output voltage of the linear regulated power supply is also the output voltage of the entire circuit of the hybrid power supply. The output voltage of the linear regulated power supply is also the user voltage.

[0037] The output voltage of the DC switching power supply is greater than the output voltage of the linear regulated power supply. Since the linear regulated power supply maintains the stability of the output voltage by adjusting the conduction degree of the internal transistor, the input voltage of the linear regulated power supply (i.e., the output voltage of the DC switching power supply) needs to be higher than the output voltage of the linear regulated power supply to provide sufficient voltage difference for the linear regulated power supply to work normally. There is a minimum voltage difference between the two. Different linear regulated power supplies have different working state requirements. For example, the minimum voltage difference required by the LDO regulator is usually between tens of millivolts and hundreds of millivolts. The minimum voltage difference of some high-performance LDO regulators only requires 50 millivolts. In order to ensure the normal operation of the linear regulated power supply, the voltage difference between the output voltage of the DC switching power supply and the output voltage of the linear regulated power supply must be at least greater than 50 millivolts.

[0038] There is a ripple component in the output voltage of the DC switching power supply. In order to ensure that the linear regulated power supply can effectively absorb these ripples and maintain the stability of the output, the voltage difference between the output voltage of the hybrid power supply (i.e. the output voltage of the linear regulated power supply) and the output voltage of the DC power supply should be greater than the minimum voltage difference requirement, and room should be left. The specific voltage difference amount for the ripple should take into account the ripple amplitude. This part of the voltage difference consideration should at least meet the following formula: ripple amplitude / output voltage of the linear regulated power supply = output voltage of the DC switching power supply / output voltage of the linear regulated power supply.

[0039] In actual applications, the user load may change. In order to ensure that the hybrid power supply can work normally under any user load state, it is necessary to appropriately increase the voltage difference between the linear regulated power supply and the DC switching power supply. In addition, the linear regulated power supply works by dissipating excess voltage in the form of heat through transistors. Therefore, the greater the voltage difference between the input voltage and the output voltage of the linear regulated power supply, the more energy the linear regulated power supply needs to consume, which will result in more heat generation and higher power consumption. The voltage difference for the dynamic load and thermal management of the linear regulated power supply is a preset value to meet

[0040] [(output voltage of DC switching power supply - output voltage of linear regulated power supply) / output voltage of linear regulated power supply]∈[1%,5%].

[0041] When the hybrid power supply circuit works normally, the output voltage of the bidirectional DC power supply is lower than the output voltage of the linear regulated power supply, the reference voltage is lower than the output voltage of the linear regulated power supply, and the bidirectional DC power supply is in a constant current load state.

[0042] When the reference voltage is lower than the output voltage of the linear regulated power supply, the bidirectional DC power supply is in a load state, and the bidirectional DC power supply absorbs current from the user load instead of providing current to the user load, so that the bidirectional DC power supply can respond quickly to load changes when needed, without causing additional burden on the hybrid power supply as a whole under normal working conditions, and almost no power consumption. When the user load changes, the bidirectional DC power supply can quickly remove the excess charge of the user load, and can also quickly provide charge to the user load.

[0043] When the user load is in a normal state, the bidirectional DC power supply is in a stable voltage and constant current load state. The normal state of the bidirectional DC power supply is a small stable voltage and constant current load state, so that the bidirectional DC power supply is always in a ready state, ready to respond to the dynamic changes of the user load at any time to quickly move the charge. Regardless of whether the user load increases or decreases, the bidirectional DC power supply can also quickly mobilize the charge and pass the user load status to the linear regulated power supply to maintain the stability of the output voltage of the linear regulated power supply.

[0044] When the state of the DC switching power supply or the user load state causes the output voltage of the linear regulated power supply to be less than the set target value, the linear regulated power supply increases the conduction degree or suspends the regulation action, and the bidirectional DC power supply supplies power to the user load, causing the output voltage of the linear regulated power supply to rise.

[0045] When the status of the DC switching power supply and the user load is abnormal, such as the output voltage of the DC switching power supply suddenly drops or the user load suddenly increases, the output voltage of the linear regulated power supply decreases, even lower than the reference voltage.

[0046] When the output voltage of the linear regulated power supply drops below the set target value (the linear regulated power supply adjusts the output voltage by adjusting the internal transistor, i.e., the field effect tube, to keep it near the set value, which is the set target value and has upper and lower limits), the linear regulated power supply quickly changes the regulation action, increases the degree of conduction, and increases the output current, helping the output voltage of the linear regulated power supply to recover above the set target value. Since the bidirectional DC power supply is in a dynamic voltage stabilization and constant current load state for a long time, it can change quickly and quickly provide electrical energy to the user load (voltage increase), and the charge flows quickly to the user load. In this process, the user voltage (the voltage at the user load) increases rapidly, preventing the output voltage of the linear regulated power supply from decreasing for a long time and stabilizing the output voltage of the linear regulated power supply.

[0047] When the output voltage of the linear regulated power supply is lower than the reference voltage, the voltage difference between the output voltage of the DC switching power supply and the output voltage of the linear regulated power supply becomes very small, and may even be close to zero or negative, causing the linear regulated power supply to fail to work properly because it does not have enough voltage drop to maintain the stability of the output voltage. The linear regulated power supply starts the voltage difference protection (to avoid entering an unstable state), automatically shuts down the internal regulating element, stops the current regulating function, reduces the power consumption of the linear regulated power supply, and prevents the linear regulated power supply from being damaged due to excessive power consumption or overheating. At the same time, it also avoids the equipment connected to the hybrid power supply from entering an unstable state, protecting the equipment components from damage. The linear regulated power supply suspends the regulation action, while the bidirectional DC power supply absorbs current from the large user load and directly provides power to the user load, helping the output voltage of the linear regulated power supply to rise. In a relatively short period of time, the rapid increase in the user voltage makes the voltage difference of the linear regulated power supply return to normal, and the linear regulated power supply will restart the regulation action and work normally again.

[0048] When the DC switching power supply state or the user load state causes the output voltage of the linear regulated power supply to be higher than the set target value, the linear regulated power supply reduces the conduction degree, the bidirectional DC power supply increases the supply current to the user load, and reduces the output voltage of the linear regulated power supply.

[0049] When the DC switching power supply state or user load state is abnormal, such as the output voltage of the DC switching power supply suddenly drops or the user load suddenly decreases, the output voltage of the linear regulated power supply will be higher than the set target value (the linear regulated power supply adjusts the output voltage by adjusting the internal transistor, that is, the field effect tube, to keep it near the set value, which is the set target value and has upper and lower limits), thereby causing damage to sensitive electronic components connected to the power supply (that is, the user load). Especially in precision instruments, communication equipment or audio equipment, excessive voltage may cause performance degradation or hardware failure.

[0050] At this time, the bidirectional DC power supply is in a dynamic voltage-stabilized and constant-current load state for a long time, so it can change quickly and increase the power supply current to the user load. By increasing the current output, the bidirectional DC power supply can effectively absorb the excess charge at the user load, thereby quickly reducing the output voltage of the linear voltage-stabilized power supply and returning it to the set target value. Through the rapid response of the bidirectional DC power supply, the output voltage of the linear voltage-stabilized power supply will drop rapidly and return to a value close to the set target value, which helps to prevent the output voltage of the linear voltage-stabilized power supply from exceeding the set value for a long time, ensuring the stability and reliability of the hybrid power supply as a whole and the system or equipment connected to it. If the output voltage of the linear voltage-stabilized power supply is higher than the set target value for a period of time, the voltage difference between the input voltage and the output voltage of the linear voltage-stabilized power supply is too large (that is, the voltage difference between the output voltage of the DC switching power supply and the output voltage of the linear voltage-stabilized power supply is too large), and the linear voltage-stabilized power supply may enter an overheating or overload state. Through the intervention of the bidirectional DC power supply, the output voltage of the linear voltage-stabilized power supply can be effectively reduced to prevent the linear voltage-stabilized power supply from being damaged due to excessive voltage difference. At the same time, the linear voltage-stabilized power supply will adjust its own conduction degree, reduce the conduction degree, and reduce its own output voltage. The coordinated operation of the bidirectional DC power supply and the linear regulated power supply can ensure the stability and reliability of the output voltage of the hybrid power supply even in the event of sudden changes in user load or external interference.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low ripple high power hybrid power supply, characterized in that: It includes a bidirectional DC power supply, a DC switching power supply and a linear voltage-regulated power supply. The input power supply is connected to the bidirectional DC power supply and the DC switching power supply respectively. The bidirectional DC power supply is connected to the user load and the linear regulated power supply respectively, the output end of the DC switching power supply is connected to the linear regulated power supply, and the output end of the linear regulated power supply is connected to the user load. The linear regulated power supply includes an operational amplifier and a field effect transistor. The non-inverting input terminal of the operational amplifier is connected to the external reference voltage, the drain of the field effect tube is connected to the DC switching power supply, the gate of the field effect tube is connected to the top corner output terminal of the operational amplifier, the source of the field effect tube is connected to the user load, and the output terminal of the linear voltage regulator is connected to the user load. The output end of the bidirectional DC power supply is connected to the inverting input end of the operational amplifier of the linear voltage regulated power supply, and the bidirectional DC power supply is connected to the user load. The output end of the DC switching power supply is connected to the drain of the field effect tube of the linear voltage-stabilized power supply, and the DC switching power supply is grounded.

2. A low ripple high power hybrid power supply according to claim 1, characterized in that: When the hybrid power supply circuit operates normally, the output terminal voltage of the DC switching power supply is greater than the output terminal voltage of the linear voltage-regulated power supply.

3. A low ripple high power hybrid power supply according to claim 2, characterized in that: Factors to consider for the voltage difference between the output voltage of a DC switching power supply and the output voltage of a linear regulated power supply include: (1) Minimum voltage difference, based on the minimum voltage difference required for the normal operation of the linear regulated power supply; (2) Ripple: voltage margin based on expected ripple amplitude; (3) Dynamic load: adding additional pressure difference according to the changes in user load; (4) Thermal management: reasonably control the thermal energy consumption of the linear regulated power supply.

4. A low ripple high power hybrid power supply according to claim 3, characterized in that: The dynamic load and thermal management voltage difference of the linear regulated power supply is a preset value, which meets the [(output voltage of DC switching power supply - output voltage of linear regulated power supply) / output voltage of linear regulated power supply]∈[1%,5%].

5. A low ripple high power hybrid power supply according to claim 1, characterized in that: When the hybrid power supply circuit works normally, the output voltage of the bidirectional DC power supply is lower than the output voltage of the linear regulated power supply, the reference voltage is lower than the output voltage of the linear regulated power supply, and the bidirectional DC power supply is in a constant current load state.

6. A low ripple high power hybrid power supply according to claim 5, characterized in that: When the state of the DC switching power supply or the user load state causes the output voltage of the linear regulated power supply to be less than the set target value, the linear regulated power supply increases the conduction degree or suspends the regulation action, and the bidirectional DC power supply supplies power to the user load, causing the output voltage of the linear regulated power supply to rise.

7. A low ripple high power hybrid power supply according to claim 5, characterized in that: When the DC switching power supply state or the user load state causes the output voltage of the linear regulated power supply to be higher than the set target value, the linear regulated power supply reduces the conduction degree, the bidirectional DC power supply increases the supply current to the user load, and reduces the output voltage of the linear regulated power supply.

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