Claims:1. A power system (100) for maintaining uniform current sharing, the system comprising:
a plurality of DC-DC converters (104-1 to 104-N) arranged in parallel, each DC-DC converter converts a variable input voltage to a fixed output voltage with a specified output voltage regulation; and
a microcontroller (224) operatively coupled to the plurality of DC-DC converters, wherein at least one DC-DC converter of the plurality of DC-DC converters automatically acts as a master and other plurality of DC-DC converter act as slaves to facilitate uniform current sharing of the plurality of DC-DC converters.
2. The power system as claimed in claim 1, wherein said plurality of DC-DC converters (104-1 to 104-N) comprises a switching converter (202) and control circuits, wherein the switching converter is any current controlled topology for providing a switched power signal, wherein the control circuits coupled to the microcontroller and comprise analog control circuit and digital control circuit for obtaining uniform current sharing with transient and steady state response, wherein uniform current sharing with a difference of 1% is obtained.
3. The power system as claimed in claim 2, wherein the analog control circuit comprises voltage error amplifier (208) that detects output voltage with variable reference voltage (210) set by digital to analog converter (DAC) of the micro-controller (224), wherein the voltage error amplifier is coupled to ideal zener diode (218) realized using op-amp and diode rectifier circuit (220) for limiting peak power of the plurality of DC-DC converters.
4. The power system as claimed in claim 1, wherein the diode rectifier circuit (220) configured to couple the output of the voltage error amplifier (208) to current sharing bus (108) through a digital switch (226), wherein the digital switch (226) configured to isolate current sharing bus (108) from the plurality of DC-DC converters during off state.
5. The power system as claimed in claim 1, wherein the current sharing bus (108) uniformly coupled to the plurality of DC-DC converters and analog control circuit senses current sharing bus voltage and adder circuit (234) supplies correction factor to compensate the error in shared currents using the DAC.
6. The power system as claimed in claim 1, wherein a diode (236) adapted to couple output current loop and output voltage loop to obtain resultant control voltage, wherein a PWM controller (240) adapted to receive the resultant control voltage to generate pulse width modulated signals, wherein the switching action of switches (246-1 to 246-4) are controlled by the generated pulse width modulated signals to facilitate multi-level protection.
7. The power system as claimed in claim 1, wherein the master calculates and communicates average current to the slaves using controller area network (CAN) communication or any other digital communication and each DC-DC converters correct the unbalance in current sharing using digital compensator and the DAC coupled to the microcontroller.
8. The power system as claimed in claim 1, wherein the microcontroller detects the master and slave DC-DC converters and adjusting slave reference voltage to prevent master-slave oscillation.
9. The power system as claimed in claim 1, wherein the microcontroller performs control scheme applicable for the plurality of DC-DC converters with maximum voltage control, minimum voltage control, isolated, non-isolated topologies designed with peak and average current mode control, wherein the microcontroller shares error current information in any type of digital communication.
10. A method (300) for maintaining uniform current sharing, said method comprising:
arranging (302) a plurality of DC-DC converters in parallel, each DC-DC converter converts a variable input voltage to a fixed output voltage with a specified output voltage regulation; and
coupling (304) a microcontroller to the plurality of DC-DC converters, wherein at least one DC-DC converter of the plurality of DC-DC converters automatically acts as a master and other plurality of DC-DC converter act as slaves to facilitate uniform current sharing of the plurality of DC-DC converters.

, Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to AC-DC and DC-DC switch-mode power supplies, and more specifically, relates to a system and method for an auto-master hybrid current sharing scheme for DC-DC parallelable power supplies.

BACKGROUND
[0002] Paralleling of power supplies to generate higher power has more advantages than designing a single power supply with high current capability. Modularity and parallel-ability help in the easy designing of systems with redundancy, a power supply with a redundant module is more reliable than a power supply with a single converter. When connecting multiple power supplies to a common load, a significant problem is the unequal delivery of current by individual power supplies. Each power supply should operate independently yet contribute an equal amount of current to the load in the presence of different output impedance, component value tolerances, temperature and the like.
[0003] A few existing current-share control schemes are known in the art, each comes with its advantages and disadvantages. One such current sharing scheme with peak current mode control includes a simple current-share paralleling technique for peak-current-mode controlled power supplies. The current-share paralleling technique discloses current sharing between two fly-back converters with peak current mode and single wire sharing bus. The current-share paralleling technique relates to the fly-back converter and brings out the complexity in designing peak current mode current sharing in fly-back converter and proposes a method for increasing the current sharing percentage. With the proposed method, the converter can achieve an output current unbalance of only 6% and it does not discuss a way to compensate component variations with temperature, which can result in a higher percentage of current sharing difference.
[0004] The single wire current sharing control arrangement has been disclosed in which the current sharing scheme is implemented using peak current mode and the auto master couples the current sharing information to bus through a diode. Auto-master with peak-current as inner loop improves the dynamic response of the complete system, but with the fixed stiff voltage reference of an individual dc-dc converter, the system can go to the low-frequency oscillation of current sharing during transients and steady-state, resulting in indefinite exchanges in the master and slave operations. The existing system is tested for low current, but while designing a DC-DC converter with high current output even small variations can result in a large difference in current sharing. The system does not disclose any information on how to compensate variations in system parameters and a way to isolate failed power stage from the bus to prevent from pulling the bus voltage, which can lead to failure of the power system.
[0005] The active current sharing of the parallel DC-DC converters system using BAT algorithm optimized two-degree-of-freedom (DOF) proportional–integral–derivative (PID) control presents the current sharing method to actively balance the output currents of the parallel DC-DC converters system. The high precision and robust ACSC scheme are disclosed to solve the output current imbalance problem. The method used an external controller circuit and bat algorithm to achieve uniform current sharing. The proposed method is complex to design and required an external controller to implement the BAT algorithm.
[0006] There is, therefore, a need in the art to provide an efficient, accurate, precise, and compact solution that obviates above-mentioned limitations.

OBJECTS OF THE PRESENT DISCLOSURE
[0007] An object of the present disclosure relates, in general, to AC-DC and DC-DC switch-mode power supplies, and more specifically, relates to a system and method for an auto-master hybrid current sharing scheme for DC-DC parallelable power supplies.
[0008] Another object of the present disclosure is to provide a system that provides uniform current sharing among the parallel power modules irrespective of variations in the system output impedances, component tolerances, variations in reference voltages and component parameter variations with temperature without degrading the output voltage regulation, transient and steady-state performance
[0009] Another object of the present disclosure is to provide a system that provides multi-level protection against output over-current and output short circuit failures.
[0010] Another object of the present disclosure is to provide a system that provides accurate control of peak power delivered by power modules.
[0011] Another object of the present disclosure is to provide a system that combines both analog circuits and digital controllers to achieve a more robust high current power supply.
[0012] Another object of the present disclosure is to provide a system that achieves both dynamic and steady-state responses.
[0013] Yet another object of the present disclosure is to provide a system that is efficient, accurate, precise, and compact.

SUMMARY
[0014] The present disclosure relates, in general, to AC-DC and DC-DC switch-mode power supplies, and more specifically, relates to a system and method for an auto-master hybrid current sharing scheme for DC-DC parallelable power supplies. The present disclosure relates to an active auto-master hybrid control current sharing method for parallelable power supplies. The method combines both analog and digital control circuits to achieve uniform current sharing with excellent transient and steady state response. The power supply is characterized with output voltage loops, output current loops and programmable ideal Zener diode for programming peak power delivered by the system. The ideal diode circuit couples the voltage error amplifier to current sharing bus through digital controlled switch to isolate failed converter from the bus. Digital compensator is implemented in micro-controller to compensate the unbalance in current sharing when multiple power supplies are connected in parallel. The control method is featured with programmable power limiting and current liming and active current balancing. The present disclosure describes the DC-DC converter with full-bridge topology, single wire current share bus and CAN communication.
[0015] In an aspect, the present disclosure relates to a power system for maintaining uniform current sharing, the system includes a plurality of DC-DC converters arranged in parallel, each DC-DC converter converts a variable input voltage to a fixed output voltage with a specified output voltage regulation and a microcontroller operatively coupled to the plurality of DC-DC converters, wherein at least one DC-DC converter of the plurality of DC-DC converters automatically acts as a master and other plurality of DC-DC converter act as slaves to facilitate uniform current sharing of the plurality of DC-DC converters.
[0016] According to an embodiment, the plurality of DC-DC converters comprises a switching converter and control circuits, wherein the switching converter is any current controlled topology for providing a switched power signal, wherein the control circuits coupled to the microcontroller and comprise analog control circuit and digital control circuit for obtaining uniform current sharing with transient and steady state response, wherein uniform current sharing with a difference of 1% is obtained.
[0017] According to an embodiment, the analog control circuit can include voltage error amplifier that detects output voltage with variable reference voltage set by digital to analog converter (DACs) of the micro-controller, wherein the voltage error amplifier is coupled to ideal zener diode realized using op-amp and diode rectifier circuit for limiting peak power of the plurality of DC-DC converters.
[0018] According to an embodiment, the diode rectifier circuit configured to couple the output of the voltage error amplifier to current sharing bus through a digital switch, wherein the digital switch configured to isolate current sharing bus from the plurality of DC-DC converters during off state.
[0019] According to an embodiment, the current sharing bus uniformly coupled to the plurality of DC-DC converters and analog control circuit senses current sharing bus voltage and adder circuit supplies correction factor to compensate the error in shared currents using the DAC.
[0020] According to an embodiment, a diode adapted to couple output current loop and output voltage loop to obtain resultant control voltage, wherein a PWM controller (204) adapted to receive the resultant control voltage to generate pulse width modulated signals, wherein the switching action of switches are controlled by the generated pulse width modulated signals to facilitate multi-level protection.
[0021] According to an embodiment, the master calculates and communicates average current to the slaves using CAN communication or any other digital communication and each DC-DC converters correct the unbalance in current sharing using digital compensator and the DAC coupled to the microcontroller.
[0022] According to an embodiment, the microcontroller detects the master and slave DC-DC converters and adjusting slave reference voltage to prevent master-slave oscillation.
[0023] According to an embodiment, the microcontroller performs control scheme applicable for the plurality of DC-DC converters with maximum voltage control, minimum voltage control, isolated, non-isolated topologies designed with peak and average current mode control, wherein the microcontroller shares error current information in any type of digital communication.
[0024] In an aspect, the present disclosure relates to a method for maintaining uniform current sharing, the method includes arranging a plurality of DC-DC converters in parallel, each DC-DC converter converts a variable input voltage to a fixed output voltage with a specified output voltage regulation and coupling a microcontroller to the plurality of DC-DC converters, wherein at least one DC-DC converter of the plurality of DC-DC converters automatically acts as a master and other plurality of DC-DC converter act as slaves to facilitate uniform current sharing of the plurality of DC-DC converters.
[0025] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0027] FIG. 1 illustrates an exemplary functional component of power system with N paralleled DC-DC converters, in accordance with an embodiment of the present disclosure.
[0028] FIG. 2A illustrates a schematic circuit arrangement of maximum voltage control peak-current mode with hybrid-current share DC-DC converter, in accordance with an embodiment of the present disclosure.
[0029] FIG. 2B illustrates a schematic circuit arrangement of minimum voltage control peak-current mode with hybrid-current share DC-DC converter, in accordance with an embodiment of the present disclosure.
[0030] FIG. 3 illustrates a flow chart of a method of maintaining uniform current sharing using the power system, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0032] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0033] The present disclosure relates, in general, to AC-DC and DC-DC switch-mode power supplies, and more specifically, relates to a system and method for an auto-master hybrid current sharing scheme for DC-DC parallelable power supplies. The system of the present disclosure enables to overcome the limitations of the prior art by providing analog and digital control techniques to achieve uniform current sharing among the paralleled DC-DC converters. The present disclosure blends the benefits of both analog circuits and digital controllers to achieve more robust high current power supply. The analog control current sharing methods provide good dynamic response, but poor steady state response, and digital current sharing methods provide good steady state response but poor dynamic response. To overcome the above limitations, the proposed system and method combines both digital and analog control schemes that can achieve both dynamic and steady state responses.
[0034] The present disclosure introduces a new control method and control circuit for a DC-DC converter of any topology, which uses peak-current mode control as inner-loop. The proposed control scheme provides uniform current sharing among the parallel power modules irrespective of variations in the system output impedances, component tolerances, variations in reference voltages and component parameter variations with temperature without degrading the output voltage regulation, transient and steady state performance.
[0035] The control scheme also provides an accurate control of peak power delivered by power modules. The control scheme is implemented with a single wire current sharing bus along with CAN communication. A 32-bit floating-point micro-controller is used for implementing CAN, digital compensator for output current loop and fixing the master among the power modules based on auto-master control scheme. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0036] The advantages achieved by the system of the present disclosure can be clear from the embodiments provided herein. The system of the present disclosure enables uniform current sharing among the parallel power modules irrespective of variations in the system output impedances, component tolerances, variations in reference voltages and component parameter variations with temperature without degrading the output voltage regulation, transient and steady state performance. The system enables multi-level protection against output over current and output short circuit failures, obtains an accurate control of peak power delivered by power modules. The system combines both analog circuits and digital controllers to achieve more robust high current power supply, and achieves dynamic and steady state responses. The system is efficient, accurate, precise, and compact. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0037] FIG. 1 illustrates an exemplary functional component of power system with N paralleled DC-DC converters, in accordance with an embodiment of the present disclosure.
[0038] Referring to FIG. 1, power system 100 (also referred to as system 100, herein) configured to maintain uniform current sharing among parallel connected DC-DC converters (104-1 to 104-N). The system 100 can include hybrid current sharing parallel connected DC-DC converters (104-1 to 104-N), the system 100 couples input voltage 102 to a load 104 through one or more DC-DC converters (104-1 to 104-N) (also referred to as DC-DC converters, herein). The power system 100 can be with either peak current mode DC-DC converter with maximum voltage control as shown in FIG.2A, or peak current mode DC-DC converter with minimum voltage control as in FIG.2B. The system 100 converts input voltage 102 to required output voltage level and couples to the load 102, either by providing isolation or without isolation based on requirement of the power system.
[0039] In an exemplary embodiment, the proposed control scheme can be used with any type of topology designed with peak current mode control or average current control. In the present disclosure, full-bridge topology is used for coupling input voltage 102 to load 104. The DC-DC converters (104-1 to 104-N) are connected to common control line 108 (also referred to as sharing bus) and controller area network (CAN) communication 110 for regulating all the peak current-mode DC-DC converters. Both ends of the CAN communication 110 are terminated with resistor 112 of 120 Ohm or any suitable range.
[0040] In an exemplary embodiment, power system 100 as presented in the example can be a 50kW, 28V, 1786A DC-DC power system that can be realized by paralleling DC-DC converters (104-1 to 104-N), where the DC-DC converters (104-1 to 104-N) can be five 10kW DC-DC power supplies. Fast detection and isolation of short circuit protection are important when paralleling high output current DC-DC power supplies. Delay in detection can lead to exceeding the energy level of the switches and results in failure. The proposed control scheme provides multi-level protection to power system 100 against output over-current and output short circuit failures.
[0041] The DC-DC converters (104-1 to 104-N) arranged in parallel, each DC-DC converter (104-1 to 104-N) converts a variable input voltage to a fixed output voltage with a specified output voltage regulation. A microcontroller 224 operatively coupled to the DC-DC converters (104-1 to 104-N), wherein at least one DC-DC converter of the DC-DC converters automatically acts as a master and other DC-DC converter act as slaves to facilitate uniform current sharing of the DC-DC converters. The DC-DC converters (104-1 to 104-N) can include a switching converter and control circuits, wherein the switching converter 202 is any current controlled topology for providing a switched power signal. The control circuits coupled to the microcontroller 224 and comprise analog control circuit and digital control circuit for obtaining uniform current sharing with transient and steady state response as shown in FIG. 2A and 2B respectively.
[0042] The analog control circuit can include voltage error amplifier 208 with variable reference voltage 210 set by digital to analog converter (DACs) of the micro-controller 224. The voltage error amplifier 208 is coupled to ideal zener diode 218 realized using op-amp and diode rectifier circuit 220 for limiting peak power of the DC-DC converters (104-1 to 104-N). The diode rectifier circuit 220 configured to couple the voltage error amplifier 208 to current sharing bus 108 through a digital switch 226. The digital switch 226 configured to isolate current sharing bus 108 from the DC-DC converters during off state. The current sharing bus 108 uniformly coupled to the DC-DC converters and analog control circuit senses current sharing bus voltage and adder circuit 234 supplies correction factor to compensate the error in shared currents using the DAC.
[0043] A diode 236 adapted to couple output current loop and output voltage loop to obtain resultant control voltage, wherein a pulse width modulation (PWM) controller 240 adapted to receive the resultant control voltage to generate pulse width modulated signals, where the switching action of switches (246-1 to 246-4) are controlled by the generated pulse width modulated signals to facilitate multi-level protection.
[0044] The master calculates and communicates average current to the slaves using CAN communication or any other digital communication and each DC-DC converters correct the unbalance in current sharing using digital compensator and the DAC coupled to the microcontroller. The microcontroller 224 detects the master and slave DC-DC converters and adjusting slave reference voltage to prevent master-slave oscillation, wherein uniform current sharing with a difference of 1% is obtained. The microcontroller 224 performs control scheme applicable for the DC-DC converters with maximum voltage control, minimum voltage control, isolated, non-isolated topologies designed with peak and average current mode control, where the microcontroller 224 shares error current information in any type of digital communication.
[0045] In an embodiment, the control scheme can include three loops, where the three loops can be output voltage control loop, output current loop and inner peak current loop. In current mode control, voltage error amplifier 208 output represent the peak power delivered by the DC-DC power supply (also referred to as DC-DC converters). The peak output power delivered by the system 100 can be controlled by saturating the voltage error amplifier 208 output, but the saturation voltage of the error amplifier varies from system to system. In high power systems, a small variation in op-amp saturated value results in a large variation in limiting power level. The proposed control scheme provides an accurate method for peak power limit with programmable Zener diode 218 designed using op-amp and diode 220.
[0046] The peak power delivered by the system can be programmed by changing the clamping level of the ideal Zener diode 218. The peak power limit prevents the failure of the switch by controlling the energy delivered by the switch during the output short circuit. Coupling the voltage error amplifier 208 output to the current sharing bus with ideal diode 220 nullifies the non-linear characteristics of the diode and maintains constant peak power limit in all paralleled DC-DC modules (104-1 to 104-N), irrespective of the load current drawn by slave high frequency filters or damping circuits.
[0047] The output current loops limit the maximum current drawn by the DC-DC power supply. Diode ORing of output voltage loop and output current loop controls the pulse width modulation. The power supply can be in voltage regulation if the output current is within the specified limit and the power supply goes to output current regulation if output current exceeds the specified current limit. By programming voltage regulation reference, and current regulation references, the same control scheme can be used for battery charger applications. The output current loops prevent the system from overloading, but because of its response time, it cannot limit the initial short circuit. Peak-power-limit limits the output power instantly but it cannot control the output current. The control system with both peak power and output current limit makes the system rugged.
[0048] The present disclosure relates to an auto-master hybrid current sharing scheme for both maximum voltage and minimum voltage control. The power system 100 can include one or more DC-DC converters (104-1 to 104-N), where at least one DC-DC converter may automatically become master and the other DC-DC converters may become slaves. In maximum voltage control, the DC-DC converters (104-1 to 104-N) with maximum set voltage reference may become master and in minimum voltage control, the DC-DC converters (104-1 to 104-N) with minimum set voltage reference may become master.
[0049] The master couples the current sharing information to the current sharing bus 108, all slaves including the master may get current sharing information from the current sharing bus 108. In all DC-DC converters (104-1 to 104-N) including the master, the inner current loop can be controlled by a single voltage error amplifier 208, which results in the excellent dynamic response of the overall power system and uniform current sharing among N paralleled converters. Due to component tolerances and temperature variations, a system with only analog control circuit can achieve <10% current sharing error. In N paralleled power system with analog control circuit, if the references are very close, the power system goes into the indefinite exchange of master-slave, resulting in the oscillation of output current.
[0050] In the N paralleled power system, the micro-controller 224 is coupled to the DC-DC converter (104-1 to 104-N) and decides the master DC-DC converter by communicating with other DC-DC converters, and shares the voltage error amplifier output to remaining controllers through digital communication. The frequency at which the voltage error amplifier output is updated in slaves is in the order of 1ms. So digital control current sharing scheme shows poor performance in transient response. To overcome the above limitation, the digital control circuit can be added with analog control circuit, resulting in a hybrid control scheme that results in excellent performance during transient and steady-state responses.
[0051] In auto-master hybrid control scheme, micro-controller 224 can detect the master in N paralleled DC-DC converters by reading the voltage error amplifier output. For example, suppose the DC-DC converter is found to be a slave, the micro-controller slightly reduces the voltage reference so that the control system can prevent output current oscillations. For every 5ms, the micro-controller in the master converter gets the current of the slaves and the master controller calculates the average current and shares it with the slave controller through CAN communication. The average current value is given as a reference to the low bandwidth output current loop digital compensator in the micro-controller. The output of the digital compensator is limited to the correct 10% of maximum output current and given to DAC. Micro-controller compensates the component tolerances and other variations in the circuit. With the proposed auto-master hybrid current sharing scheme, the power system 100 with N parallel DC-DC converter can achieve unbalance <1%.
[0052] The embodiments of the present disclosure described above provide several advantages. The system of the present disclosure enables uniform current sharing among the parallel power modules irrespective of variations in the system output impedances, component tolerances, variations in reference voltages and component parameter variations with temperature without degrading the output voltage regulation, transient and steady-state performance. The system enables multi-level protection against output over-current and output short circuit failures, obtains an accurate control of peak power delivered by power modules. The system combines both analog circuits and digital controllers to achieve a more robust high current power supply and achieves dynamic and steady-state responses. The system is efficient, accurate, precise, and compact.
[0053] FIG. 2A illustrates a schematic circuit arrangement of maximum voltage control peak-current mode with hybrid-current share DC-DC converter, in accordance with an embodiment of the present disclosure. The interconnected circuit blocks for respective peak current mode with maximum voltage control shown in FIG. 2A.
[0054] A full-bridge converter 202 configured to couple the input voltage to load 106. The output voltage 206 of the converter 202 is sensed and conveyed to the voltage error amplifier 208. The voltage error amplifier 208 adapted for providing a voltage error signal scaled to the difference between the output voltage and a voltage reference 210. The voltage sensing point 206 can either be local or remote and sensed voltage gain can be adjusted using voltage divider resistor network or can be amplified using amplifier 208 according to reference requirement. The output regulation point can be set by reference voltage 210.
[0055] The output current 212 of the power converters sensed through given current error amplifier 214. The output current regulation point can be set by current reference voltage 216. The output of the voltage error amplifier 208 is coupled to ideal zener diode 218 realized using opamp and ideal diode rectifier circuit 220. The ideal zener diode 218 limits the maximum error voltage coupling to current sharing bus, in turn limiting the peak output power delivered by the DC-DC converters (104-1 to 104-N). The maximum power limit can be set by power reference voltage 222. The reference voltages (210, 216, 222) can be fixed or variable. In the present disclosure, all reference voltages are variable and set by DACs of the micro-controller 224.
[0056] The ideal diode 220 couples the voltage error amplifier 208 to output current sharing bus 108 through digital switch 226, which is controlled by the micro-controller 224. The jumper 228 couples the current sharing bus to the analog buffer 230 and high-frequency noise filter 232. All the DC-DC converters (104-1 to 104-N) are connected through CAN communication lines CANH and CANL to controller 224. Adder 234 couples the DAC voltage from the controller 224 to the sensed current sharing voltage. The output voltage of the adder 234 applied can be coupled to the diode 236. The minimum voltage Vc 238 of the current error amplifier 214 and output voltage from the adder 235 is coupled to PWM controller 240. Primary current sensor 242 senses the peak current of the converter, and the sensed peak current is added to the slope compensation component according to requirement. Slope compensated peak current 244 is coupled to the PWM controller 240. The PWM controller 240 compares slope compensated peak current and generates a pulse width modulated signals 204-1 and 204-2. The switching action of switches (246-1 to 246-4) is controlled by the pulse width modulated signals 204-1 and 204-2.
[0057] FIG. 2B illustrates a schematic circuit arrangement of minimum voltage control peak-current mode with hybrid-current share DC-DC converter, in accordance with an embodiment of the present disclosure. The interconnected circuit blocks for respective peak current mode with minimum voltage control shown in FIG. 2B.
[0058] FIG. 3 illustrates a flow chart of a method of maintaining uniform current sharing using the power system, in accordance with an embodiment of the present disclosure.
[0059] Referring to FIG. 3, the method 300 for maintaining uniform current sharing, the method includes at block 302, the plurality of DC-DC converters is arranged in parallel, each DC-DC converter converts a variable input voltage to a fixed output voltage with a specified output voltage regulation. At block 304, a microcontroller coupled to the plurality of DC-DC converters, wherein at least one DC-DC converter of the plurality of DC-DC converters automatically acts as a master and other plurality of DC-DC converter act as slaves to facilitate uniform current sharing of the plurality of DC-DC converters.
[0060] It will be apparent to those skilled in the art that the system 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0061] The present disclosure provides a system that enables uniform current sharing among the parallel power modules irrespective of variations in the system output impedances, component tolerances, variations in reference voltages and component parameter variations with temperature without degrading the output voltage regulation, transient and steady-state performance
[0062] The present disclosure provides a system that enables multi-level protection against output over-current and output short circuit failures.
[0063] The present disclosure provides a system that obtains an accurate control of peak power delivered by power modules.
[0064] The present disclosure provides a system that combines both analog circuits and digital controllers to achieve a more robust high current power supply.
[0065] The present disclosure provides a system that achieves both dynamic and steady-state responses.
[0066] The present disclosure provides a system that is efficient, accurate, precise, and compact.