Parallel power supply system power scheduling method and device, medium, controller and product

Abstract

The invention provides a parallel power supply system power scheduling method and device, a medium, a controller and a product, the parallel power supply system comprises more than two power supply modules which are connected in parallel, and the power scheduling method comprises the following steps: after the parallel power supply system reaches a steady state, starting the medium; based on the approximate efficiency characteristic curve of each power supply module in the more than two power supply modules, calculating expected output power of each power supply module by adopting a heuristic optimization algorithm; calculating a second load error adjustment amount of each power supply module according to the calculated expected output power of each power supply module and the calculated actual output power of each power supply module; and carrying out load distribution control on each power supply module of the parallel power supply system according to the determined second load error adjustment amount of each power supply module. According to the scheme provided by the invention, load distribution with optimal efficiency can be realized in a steady state.

Description

Technical Field

[0001] The present invention relates to the field of control, and in particular to a power scheduling method, device, medium, controller and product for a parallel power supply system, and specifically to a power scheduling method, device, computer-readable medium, controller and computer program product for a parallel power supply system. Background Art

[0002] As more and more electrical devices require more power, the requirements for the output power of switching power supplies are also getting higher and higher. Considering that the output power of a single power module is often limited, parallel power supply systems have come into being. While parallel DC power supplies increase system capacity, they also have the advantages of redundant power supply, greater reliability, and high cost performance.

[0003] However, there are differences in the parameter design of the components in each power module in the parallel system. If the power modules are directly operated in parallel without power scheduling control, the output current of the power modules may be very different. The modules with large output currents are also subject to greater electrical and thermal stresses, which will affect the service life of the power modules. Summary of the invention

[0004] The main purpose of the present invention is to overcome the defects of the above-mentioned related technologies and to provide a power scheduling method, device, medium, controller and product for a parallel power supply system to solve the problem in the related technology that the power modules are directly operated in parallel without power scheduling control, which may result in large differences in the output currents of the power modules.

[0005] On the one hand, the present invention provides a power scheduling method for a parallel power supply system, wherein the parallel power supply system includes more than two power supply modules connected in parallel, and the power scheduling method includes: after the parallel power supply system reaches a steady state, based on the approximate efficiency characteristic curve of each of the more than two power supply modules, using a heuristic optimization algorithm to calculate the expected output power of each of the power supply modules; according to the calculated expected output power of each of the power supply modules and the actual output power of each of the power supply modules, calculating the second load error adjustment amount of each of the power supply modules; and according to the determined second load error adjustment amount of each of the power supply modules, performing load distribution control of each of the power supply modules in the parallel power supply system.

[0006] Optionally, it also includes: when the parallel power supply system has not reached a steady state, using current sharing control to perform load distribution on the parallel power supply system to obtain a first load error adjustment amount for each of the power supply modules; and performing load distribution control on each of the power supply modules in the parallel power supply system based on the obtained first load error adjustment amount for each of the power supply modules.

[0007] Optionally, it also includes: determining whether the parallel power supply system has reached a steady state based on the amplitude change of the total load power of the parallel power supply system; wherein, when the amplitude change of the total float power of the parallel power supply system is less than a preset threshold value for N consecutive cycles, the parallel power supply system has reached a steady state.

[0008] Optionally, based on the approximate efficiency characteristic curve of each of the more than two power modules, a heuristic optimization algorithm is used to calculate the expected output power of each of the power modules, including: establishing a system efficiency optimization objective function based on the approximate efficiency characteristic curve of each of the more than two power modules; using a heuristic optimization algorithm to optimize the established system efficiency optimization objective function to obtain the expected output power of each of the power modules; the heuristic algorithm includes: at least one of a simulated annealing algorithm, a particle swarm algorithm, an ant colony algorithm, and a genetic algorithm.

[0009] Optionally, calculating the second load error adjustment amount of each power module according to the calculated expected output power of each power module and the actual output power of each power module includes: the second load error adjustment amount of each power module is calculated according to the following formula using a PI control algorithm:

[0010] Δ U2i =k p e oi +k i ∫e oi dt

[0011] Δ U2i is the second load error adjustment of the ith power module, kp and ki are proportional gain and integral gain respectively, e oi is the output power error between the expected output power and the actual output power of the i-th power module.

[0012] Optionally, the load distribution control of each power module in the parallel power system is performed according to the determined second load error adjustment amount of each power module, including: according to a preset control logic, and according to the first load error adjustment amount of each power module and the second load error adjustment amount of each power module obtained by performing load distribution of the parallel power system using current sharing control, the load distribution control of each power module in the parallel power system is performed; the preset control logic includes: determining the load distribution output control amount Δ of each power module according to the following formula Ui :

[0013] Δ Ui =KΔ U2i +(1-K)Δ U1i

[0014] Among them, Δ U1i is the first load error adjustment amount of each power module obtained by using current sharing control to distribute the load of the parallel power system, Δ U2i is the second load error adjustment amount for each power module, K is the switching coefficient, and when the parallel power supply system reaches a steady state, it is determined whether K is equal to 1 at a first preset time interval, and if K is not equal to 1, then K=K+Kstep, until K=1, where Kstep is a preset step length.

[0015] On the other hand, the present invention provides a power scheduling device for a parallel power supply system, wherein the parallel power supply system includes more than two power supply modules connected in parallel, and the power scheduling device includes: a first calculation unit, which is used to calculate the expected output power of each power supply module based on the approximate efficiency characteristic curve of each of the more than two power supply modules and using a heuristic optimization algorithm after the parallel power supply system reaches a steady state; a second calculation unit, which is used to calculate the second load error adjustment amount of each power supply module according to the expected output power of each power supply module calculated by the first calculation unit and the actual output power of each power supply module; and a control unit, which is used to perform load distribution control of each power supply module in the parallel power supply system according to the second load error adjustment amount of each power supply module determined by the second calculation unit.

[0016] Optionally, the control unit is also used to: when the parallel power supply system has not reached a steady state, use current sharing control to perform load distribution on the parallel power supply system to obtain a first load error adjustment amount for each of the power supply modules; and perform load distribution control on each of the power supply modules in the parallel power supply system based on the obtained first load error adjustment amount for each of the power supply modules.

[0017] Optionally, it also includes: a determination unit, used to determine whether the parallel power supply system has reached a steady state based on the amplitude change of the total load power of the parallel power supply system; wherein, when the amplitude change of the total float power of the parallel power supply system is less than a preset threshold value for N consecutive cycles, the parallel power supply system has reached a steady state.

[0018] Optionally, the first calculation unit uses a heuristic optimization algorithm to calculate the expected output power of each of the two or more power modules based on the approximate efficiency characteristic curve of each of the two or more power modules, including: establishing a system efficiency optimization objective function based on the approximate efficiency characteristic curve of each of the two or more power modules; using a heuristic optimization algorithm to optimize the established system efficiency optimization objective function to obtain the expected output power of each of the power modules; the heuristic algorithm includes: at least one of a simulated annealing algorithm, a particle swarm algorithm, an ant colony algorithm, and a genetic algorithm.

[0019] Optionally, the second calculation unit calculates the second load error adjustment amount of each power module according to the expected output power of each power module and the actual output power of each power module calculated by the first calculation unit, including: the second load error adjustment amount of each power module is calculated according to the following formula using a PI control algorithm:

[0020] Δ U2i =k p e oi +k i ∫e oi dt

[0021] Δ U2i is the second load error adjustment of the ith power module, kp and ki are proportional gain and integral gain respectively, e oi is the output power error between the expected output power and the actual output power of the i-th power module.

[0022] Optionally, the control unit performs load distribution control of each power module of the parallel power supply system according to the determined second load error adjustment amount of each power module, including: the preset control logic includes: determining the load distribution output control amount Δ of each power module according to the following formula Ui :

[0023] Δ Ui =KΔ U2i +(1-K)Δ U1i

[0024] According to the load distribution of each power module, the output control quantity Δ Ui Perform load distribution control on each power module of the parallel power supply system; wherein Δ U1i is the first load error adjustment amount of each power module obtained by using current sharing control to distribute the load of the parallel power system, Δ U2i is the second load error adjustment amount for each power module, K is the switching coefficient, and when the parallel power supply system reaches a steady state, it is determined whether K is equal to 1 at a first preset time interval, and if K is not equal to 1, then K=K+Kstep, until K=1, where Kstep is a preset step length.

[0025] Another aspect of the present invention provides a storage medium having a computer program stored thereon, wherein the program implements the steps of any of the aforementioned methods when executed by a processor.

[0026] In another aspect, the present invention provides a controller, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the aforementioned methods when executing the program.

[0027] In another aspect, the present invention provides a controller, comprising any of the aforementioned power scheduling devices for parallel power supply systems.

[0028] In yet another aspect, the present invention provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0029] According to the technical solution of the present invention, the power distribution scheme with the best overall efficiency is calculated in real time through the efficiency curve of the single power supply module, which can greatly improve the overall efficiency of the parallel power supply.

[0030] According to the technical solution of the present invention, power scheduling and allocation based on optimal efficiency in steady state is added, and a composite control logic of current equalization and optimal efficiency is implemented based on steady-state judgment, so as to achieve the use of current equalization control scheme in dynamic process and load distribution with optimal efficiency in steady state. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 It is a method schematic diagram of an embodiment of a power scheduling method for a parallel power supply system provided by the present invention;

[0033] Figure 2 A control schematic diagram of a specific embodiment of the power dispatching method for a parallel power supply system provided by the present invention is shown;

[0034] Figure 3 A schematic flow chart of the steps of calculating the expected output power of each of the two or more power modules using a heuristic optimization algorithm based on the approximate efficiency characteristic curve of each of the two or more power modules according to the present invention is shown;

[0035] Figure 4 shows the approximate efficiency characteristic curve of a single power module;

[0036] Figure 5 A flowchart showing the efficiency optimization solution process of the simulated annealing algorithm is shown;

[0037] Figure 6 A schematic diagram of steady-state changes in the preset control logic is shown;

[0038] Figure 7 It is a structural block diagram of an embodiment of a power dispatching device for a parallel power supply system provided by the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] In the research on power dispatching of parallel power supply systems in related technologies, current sharing control technology is mainly used. Common current sharing methods include passive current sharing method, average current sharing method, designated master-slave current sharing method, maximum current sharing method, etc. However, parallel current sharing control does not take into account the overall efficiency of the system. If the parallel DC power supply system is composed of DC power supplies of different power levels, then the efficiency characteristics of DC power supply systems of different power levels must be different. Even if the power levels of each power supply module in parallel are the same, due to the differences in components and parasitic parameters in the power supply circuit and the differences in control parameters, the efficiency characteristics of each power supply module will be different. The load distribution of each power supply module will affect the overall efficiency of the system. If only the traditional current sharing load distribution is adopted for the parallel power supply system, then the efficiency of the entire parallel DC power supply system cannot be maximized. Therefore, the present invention proposes a control strategy for non-uniform power dispatching of parallel voltage systems with optimal comprehensive efficiency.

[0042] The present invention provides a power dispatching method for a parallel power supply system. The parallel power supply system comprises more than two power supply modules connected in parallel. Figure 2 FIG. 2 is a control schematic diagram of a specific embodiment of the power dispatching method for a parallel power supply system provided by the present invention. Figure 2As shown, taking the parallel power supply system including two parallel power modules (power module 1, power module 2) as an example, each power module adopts voltage and current dual closed-loop control and PWM control. The voltage controller and current controller of each power module adopt PID controller. The voltage loop achieves the purpose of stabilizing the output voltage, and the current loop introduces current negative feedback (such as Figure 2 As shown in I L1 and I L2 ), improve the anti-interference ability and response speed of the switching power supply system, and limit the maximum current of the power switch. Due to the introduction of current negative feedback, it is easy to realize the load distribution control of the parallel power supply system. Uref is the reference voltage and Uout is the output voltage. The parallel power supply system also includes a current sharing controller for current sharing control of the parallel power supply system. The current sharing controller can use the maximum current sharing method to perform current sharing control.

[0043] Figure 1 It is a method schematic diagram of an embodiment of a power scheduling method for a parallel power supply system provided by the present invention.

[0044] like Figure 1 As shown, according to an embodiment of the present invention, the power dispatching method of the parallel power supply system at least includes step S130, step S140 and step S150. Preferably, before step S130, it also includes step S110 and step S120.

[0045] Step S110, when the parallel power supply system has not reached a steady state, current sharing control is used to distribute the load of the parallel power supply system to obtain a first load error adjustment amount of each of the power modules.

[0046] Specifically, the power module with the largest output power is selected from all power modules as the main module, and the power of all power modules follows the maximum power Pmax, that is, the expected power of all power modules is Pmax. Then, the first load error adjustment amount can be obtained according to the PI controller.

[0047] Step S120 , performing load distribution control on each power module of the parallel power supply system according to the obtained first load error adjustment amount of each power module.

[0048] The situation in which the parallel power supply system has not reached a steady state includes, for example, the startup process of the parallel power supply system or the load mutation process of the parallel power supply system, that is, during the startup process of the parallel power supply system or the load mutation process of the parallel power supply system, current equalization control is used to distribute the load of the parallel power supply system. Specifically, the parallel power supply system includes a current equalization controller for performing current equalization control on the parallel power supply system. The current equalization controller uses the maximum current equalization method to perform current equalization control. The maximum current equalization method is used to select the power supply module with the largest current from all the power supply modules in the parallel power supply system as the main power supply module, and perform current equalization control on the entire parallel power supply system. Compared with other current equalization control methods, the maximum current equalization method has good reliability. The load distribution of the parallel power supply system is performed using current equalization control, and the load error adjustment amount of each power supply module is obtained, which is recorded as the first load error adjustment amount Δ of each power supply module. U1i .For example, Figure 2 The first load error adjustment amounts of the two power modules connected in parallel are Δ U11 and Δ U12 .

[0049] Step S130, after the parallel power supply system reaches a steady state, based on the approximate efficiency characteristic curve of each of the two or more power modules, a heuristic optimization algorithm is used to calculate the expected output power of each of the power modules.

[0050] refer to Figure 2 As shown, the parallel power supply system also includes an optimal efficiency power scheduler for determining the expected output power of each of the power modules. The power efficiency is considered for steady-state operation conditions, and the current sharing control scheme is used to achieve load distribution during dynamic processes such as power startup or load mutation. When the system reaches a steady state, it gradually transitions to power scheduling control based on optimal efficiency.

[0051] Specifically, based on the amplitude change of the total load power of the parallel power supply system, it is determined whether the parallel power supply system has reached a steady state, wherein when the amplitude change of the total load power of the parallel power supply system is less than a preset threshold value for N consecutive cycles, the parallel power supply system has reached a steady state.

[0052] For example, if N consecutive cycles are judged, and the total load power at the current moment minus the total load power at the previous moment is less than the preset threshold, it is determined that the parallel power system has reached a steady state. (Optimal efficiency power scheduler) starts calculating the efficiency allocation and outputs the expected output power p of each power module. oi,ref .

[0053] Figure 3The flowchart of the steps of calculating the expected output power of each power module using a heuristic optimization algorithm based on the approximate efficiency characteristic curve of each of the two or more power modules according to the present invention is shown. Figure 3 As shown, in a specific implementation, step S130 includes step S131 and step S132.

[0054] Step S131 : establishing a system efficiency optimization objective function based on the approximate efficiency characteristic curve of each of the two or more power modules.

[0055] Specifically, obtain the approximate efficiency characteristic curve of a single power module Since most parasitic parameters are unmeasurable, it is impossible to directly draw the actual efficiency characteristic curve of the power supply using the formula. Therefore, based on the experiment, the approximate efficiency characteristic curve of a single power supply module can be obtained by fitting the data points. like Figure 4 shown. Figure 4 The figure shows the approximate efficiency characteristic curve of a single power module. The horizontal axis represents the output power and the vertical axis represents the efficiency of the power module.

[0056] According to the approximate efficiency characteristic curve of a single power module, the system efficiency optimization objective function is established. Approximate efficiency characteristic curve of the i-th single power module The total efficiency η of the system can be determined by the output power of each power module and the efficiency characteristic curve of each power module:

[0057]

[0058] in, is the output power of the ith power module, p load is the total load power of the parallel power system. Therefore, the efficiency optimization problem can be transformed into the problem of solving the maximum system efficiency, that is,

[0059]

[0060] Where i = 1, 2, ..., n, maxη represents the maximum efficiency of the parallel power supply system. Considering that the sum of the output power of each power module is equal to the total load power of the parallel power supply system, and the rated power value constrains the power upper limit, the optimization problem is to solve the maximum efficiency with constraints, that is,

[0061]

[0062] Where i=1,2,...,n. is the preset minimum output power of the ith power module, is the preset maximum output power of the i-th power module, and eliminating the equality constraint, the system efficiency optimization objective function of the parallel power system can be obtained as follows:

[0063]

[0064] Among them, i = 1, 2, ..., n-1. Therefore, the role of the optimal efficiency power scheduler is to solve the maximum value of the constrained n-1 variable function.

[0065] Step S132: using a heuristic optimization algorithm to optimize the established system efficiency optimization objective function to obtain the expected output power of each of the power modules.

[0066] Specifically, the established system efficiency optimization objective function is optimized to obtain the expected output power of each power module that makes the efficiency of the parallel power supply system the highest. The heuristic algorithm may adopt at least one of a simulated annealing algorithm, a particle swarm algorithm, an ant colony algorithm, and a genetic algorithm. In a specific embodiment, a simulated annealing algorithm is used to optimize the established system efficiency optimization objective function to obtain the expected output power of each power module. Specifically, a simulated annealing algorithm is used to optimize the efficiency to obtain an n-1 dimensional vector composed of the expected values ​​of the output power of each power module in the parallel power supply system.

[0067] The solution vector in the efficiency optimization process using the simulated annealing algorithm is an n-1 dimensional vector composed of the expected value of the output power of the power module. The optimization process of the simulated annealing algorithm may include the following steps:

[0068] Step 1, set the algorithm parameters, including the initial temperature T, the minimum temperature Tmin, the temperature drop rate a, and the number of iterations L at each temperature;

[0069] Step 2, randomly generate an initial solution S0, and set the current solution S = S0;

[0070] Step 3, let the current temperature t = T, when t>Tmin, loop steps 4 to 9, otherwise, output the current solution S;

[0071] Step 4, set the iteration counter k=1, when k≤L, loop steps 5 to 8, otherwise, execute step 9;

[0072] Step 5, apply random perturbation to the current solution S to transform it into a new solution S`;

[0073] Step 6, calculate the increment △ = f(S`)-f(S);

[0074] Step 7, if △<0, then take S` as the new current solution, otherwise accept S` as the new current solution with probability exp(-△ / t);

[0075] Step 8, the iteration counter is incremented, k=k+1;

[0076] Step 9, reduce the current temperature, T = a*T;

[0077] The optimization process of the above simulated annealing algorithm can be specifically referred to Figure 5 , Figure 5 The flowchart of the efficiency optimization solution process of the simulated annealing algorithm is shown. The above algorithm can be used to calculate the expected output power p of each power module. oi,ref For example, Figure 2 As shown in the figure, the expected output powers of the two power modules in parallel are p o1,ref ,p o2,ref .

[0078] Step S140: Calculate a second load error adjustment amount of each of the power modules according to the calculated expected output power of each of the power modules and the actual output power of each of the power modules.

[0079] Preferably, the parallel power supply system further comprises a load distribution controller (reference Figure 2 The load distribution controller is used to determine the second load error adjustment amount of each power module according to the expected output power of each power module and the actual output power of each power module, so as to perform load distribution control on the two or more parallel power modules. The load distribution controller can adopt a proportional controller, and the second load error adjustment amount of each power module is calculated by the PI control algorithm according to the following formula:

[0080] Δ U2i =k p e oi +k i ∫e oi dt

[0081] Among them, Δ U2i is the second load error adjustment value of each power module (the second load error adjustment value of the i-th power module, i represents the i-th power module), kp and ki are proportional gain and integral gain respectively, e oi is the output power error between the expected output power and the actual output power of the i-th power module.

[0082] For example, Figure 2 As shown in , the output power errors between the expected output power and the actual output power of the two power modules connected in parallel are calculated as eo1 and e o2 , the load error adjustment of the two power modules in parallel is calculated by PI control algorithm and is Δ U21 and Δ U22 .

[0083] Step S150: performing load distribution control of each power module of the parallel power supply system according to the determined second load error adjustment amount of each power module.

[0084] In a specific embodiment, load distribution control of each power module in the parallel power supply system is performed according to a preset control logic and based on the first load error adjustment amount of each power module and the second load error adjustment amount of each power module obtained by load distribution of the parallel power supply system using current equalization control.

[0085] For example, Figure 2 As shown in the figure, the expected output power of the two power modules connected in parallel is calculated to be p o1,rdf ,p o2,ref After that, the output power errors between the expected output power and the actual output power of the two power modules in parallel are calculated as e o1 and e o2 , the second load error adjustment values ​​of the two power modules in parallel are obtained by using the PI control algorithm: U21 and Δ U22 The first load error adjustment values ​​of the two parallel power modules obtained by the current sharing control algorithm are Δ U11 and Δ U12 According to the preset control logic (composite control logic), the first load error adjustment value Δ of the two power modules connected in parallel is U11 and Δ U12 and the second load error adjustment Δ U21 and Δ U22 Get the load sharing output control quantity Δ of the two power modules in parallel U1 and Δ U2 .

[0086] In a specific implementation, the preset control logic includes: determining the load distribution Δ of each power module according to the following formula: Ui Output control quantity:

[0087] Δ Ui =KΔ U2i +(1-K)Δ U1i

[0088] According to the load distribution of each power module, the output control quantity Δ UiPerform load distribution control on each power module of the parallel power supply system.

[0089] Among them, Δ Ui The output control amount for each power module load distribution is the load error adjustment amount, Δ U1i is the first load error adjustment amount of each power module, the first load error adjustment amount of each power module is the load error adjustment amount of each power module obtained by using current sharing control to distribute the load of the parallel power system, Δ U2i is the second load error adjustment amount of each power module, K is the switching coefficient, and when the parallel power supply system reaches a steady state, whether K is equal to 1 is determined every first preset time, and if K is not equal to 1, K=K+Kstep, until K=1.

[0090] Specifically, the load distribution control of each power module of the parallel power system is performed according to the value of the switching coefficient K at every second preset time. That is, the load distribution Δ of each power module is determined according to the above formula. Ui Output control amount: the first preset time and the second preset time may be the same or different.

[0091] The change logic of K can be as follows Figure 6 As shown, when the system has not reached a steady state, K = 0. When the system changes to a steady state, the switching coefficient K slowly changes to 1, and the change speed is determined by the preset step length K. step The load distribution result is determined by the efficiency optimization scheduler; when the parallel power system reaches a steady state, it is determined whether K is equal to 1. If K is not equal to 1, then K = K + Kstep, and continue to determine whether K is equal to 1 until K = 1, and then it ends. When the system exits the steady state, the switching coefficient immediately becomes 0, and the load distribution result is determined by the current sharing controller.

[0092] To clearly illustrate the technical solution of the present invention, Figure 2 The execution process of the power scheduling method for the parallel power supply system provided by the present invention is described.

[0093] like Figure 2 As shown, the total load power Pload of the parallel power supply system is calculated based on the actual output power of the two parallel power supply modules, and a steady-state judgment is performed. When it is determined that the parallel power supply system has reached a steady state, the expected output powers of the two parallel power supply modules are calculated to be p o1,ref ,p o2,Ref After that, the output power errors between the expected output power and the actual output power of the two power modules in parallel are calculated as e o1 and e o2 ,, the second load error adjustment values ​​of the two power modules in parallel are obtained by using the PI control algorithm:U21 and Δ U22 The first load error adjustment values ​​of the two parallel power modules obtained by the current sharing control algorithm are Δ U11 and Δ U12 , according to the preset control logic (composite control logic), according to the first load error adjustment amount Δ of the two power modules connected in parallel U11 and Δ U12 and the second load error adjustment Δ U21 and Δ U22 Get the load sharing output control quantity Δ of the two power modules in parallel U1 and Δ U2 .

[0094] The present invention also provides a power dispatching device for a parallel power supply system. The parallel power supply system comprises more than two power supply modules connected in parallel. Figure 2 FIG. 2 is a control schematic diagram of a specific embodiment of the power dispatching method for a parallel power supply system provided by the present invention. Figure 2 As shown, taking the parallel power supply system including two parallel power modules (power module 1, power module 2) as an example, each power module adopts voltage and current dual closed-loop control and PWM control. The voltage controller and current controller of each power module adopt PID controller. The voltage loop achieves the purpose of stabilizing the output voltage, and the current loop introduces current negative feedback (such as Figure 2 As shown in I L1 and I L2 ), improve the anti-interference ability and response speed of the switching power supply system, and limit the maximum current of the power switch. Due to the introduction of current negative feedback, it is easy to realize the load distribution control of the parallel power supply system.

[0095] The parallel power supply system further includes a current sharing controller for performing current sharing control on the parallel power supply system. The current sharing controller can perform current sharing control using a maximum current sharing method.

[0096] Figure 7 FIG. 1 is a structural block diagram of an embodiment of a power dispatching device for a parallel power supply system provided by the present invention. Figure 7 As shown, the parallel power supply system power dispatching device 100 includes: a first calculation unit 110, a second calculation unit 120 and a control unit 130.

[0097] The first calculation unit 110 is used to calculate the expected output power of each of the two or more power modules by using a heuristic optimization algorithm based on the approximate efficiency characteristic curve of each of the two or more power modules after the parallel power supply system reaches a steady state.

[0098] refer to Figure 2As shown, the parallel power supply system also includes an optimal efficiency power scheduler for determining the expected output power of each of the power modules. The power efficiency is considered for steady-state operation conditions, and the current sharing control scheme is used to achieve load distribution during dynamic processes such as power startup or load mutation. When the system reaches a steady state, it gradually transitions to power scheduling control based on optimal efficiency.

[0099] The device 100 may further include: a determination unit (not shown). The determination unit is used to determine whether the parallel power system has reached a steady state according to the amplitude change of the total load power of the parallel power system; wherein, when the amplitude change of the total float power of the parallel power system is less than a preset threshold value in N consecutive cycles, the parallel power system has reached a steady state.

[0100] For example, if N consecutive cycles are judged, and the total load power at the current moment minus the total load power at the previous moment is less than the preset threshold, it is determined that the parallel power system has reached a steady state. (Optimal efficiency power scheduler) starts calculating the efficiency allocation and outputs the expected output power p of each power module. oi,ref .

[0101] In a specific embodiment, the first calculation unit 110 uses a heuristic optimization algorithm to calculate the expected output power of each of the two or more power modules based on the approximate efficiency characteristic curve of each of the two or more power modules, including: establishing a system efficiency optimization objective function based on the approximate efficiency characteristic curve of each of the two or more power modules; and using a heuristic optimization algorithm to optimize the established system efficiency optimization objective function to obtain the expected output power of each of the power modules.

[0102] Specifically, obtain the approximate efficiency characteristic curve of a single power module Since most parasitic parameters are unmeasurable, it is impossible to directly draw the actual efficiency characteristic curve of the power supply using the formula. Therefore, based on the experiment, the approximate efficiency characteristic curve of a single power supply module can be obtained by fitting the data points. like Figure 4 shown. Figure 4 The figure shows the approximate efficiency characteristic curve of a single power module. The horizontal axis represents the output power and the vertical axis represents the efficiency of the power module.

[0103] According to the approximate efficiency characteristic curve of a single power module, the system efficiency optimization objective function is established. Approximate efficiency characteristic curve of the i-th single power module The total efficiency η of the system can be determined by the output power of each power module and the efficiency characteristic curve of each power module:

[0104]

[0105] in, is the output power of the ith power module, p load is the total load power of the parallel power system. Therefore, the efficiency optimization problem can be transformed into the problem of solving the maximum system efficiency, that is,

[0106]

[0107] Where i = 1, 2, ..., n, maxη represents the maximum efficiency of the parallel power supply system. Considering that the sum of the output power of each power module is equal to the total load power of the parallel power supply system, and the rated power value constrains the power upper limit, the optimization problem is to solve the maximum efficiency with constraints, that is,

[0108]

[0109] Where i=1,2,...,n. is the preset minimum output power of the ith power module, is the preset maximum output power of the i-th power module, and eliminating the equality constraint, the system efficiency optimization objective function of the parallel power system can be obtained as follows:

[0110]

[0111] Among them, i = 1, 2, ..., n-1. Therefore, the role of the optimal efficiency power scheduler is to solve the maximum value of the constrained n-1 variable function.

[0112] The established system efficiency optimization objective function is optimized to obtain the expected output power of each power module that makes the efficiency of the parallel power supply system the highest. The heuristic algorithm may adopt at least one of a simulated annealing algorithm, a particle swarm algorithm, an ant colony algorithm, and a genetic algorithm. In a specific embodiment, a simulated annealing algorithm is used to optimize the established system efficiency optimization objective function to obtain the expected output power of each power module. Specifically, a simulated annealing algorithm is used to optimize the efficiency to obtain an n-1 dimensional vector composed of the expected values ​​of the output power of each power module in the parallel power supply system.

[0113] The solution vector in the efficiency optimization process using the simulated annealing algorithm is an n-1 dimensional vector composed of the expected value of the output power of the power module. The optimization process of the simulated annealing algorithm may include the following steps:

[0114] Step 1, set the algorithm parameters, including the initial temperature T, the minimum temperature Tmin, the temperature drop rate a, and the number of iterations L at each temperature;

[0115] Step 2, randomly generate an initial solution S0, and set the current solution S = S0;

[0116] Step 3, let the current temperature t = T, when t>Tmin, loop steps 4 to 9, otherwise, output the current solution S;

[0117] Step 4, set the iteration counter k=1, when k≤L, loop steps 5 to 8, otherwise, execute step 9;

[0118] Step 5, apply random perturbation to the current solution S to transform it into a new solution S`;

[0119] Step 6, calculate the increment △ = f(S`)-f(S);

[0120] Step 7, if △<0, then take S` as the new current solution, otherwise accept S` as the new current solution with probability exp(-△ / t);

[0121] Step 8, the iteration counter is incremented, k=k+1;

[0122] Step 9, reduce the current temperature, T = a*T;

[0123] The optimization process of the above simulated annealing algorithm can be specifically referred to Figure 5 , Figure 5 The flowchart of the efficiency optimization solution process of the simulated annealing algorithm is shown. The above algorithm can be used to calculate the expected output power p of each power module. oi,ref For example, Figure 2 As shown in the figure, the expected output powers of the two power modules in parallel are p o1,ref ,p o2,ref .

[0124] The second calculation unit 120 is used to calculate a second load error adjustment amount for each of the power modules according to the expected output power of each of the power modules and the actual output power of each of the power modules calculated by the first calculation unit.

[0125] Preferably, the parallel power supply system further includes a load distribution controller. The load distribution controller is used to determine the second load error adjustment amount of each power module according to the expected output power of each power module and the actual output power of each power module, so as to perform load distribution control on the two or more parallel power modules. The load distribution controller can adopt a proportional controller, and the second load error adjustment amount of each power module is calculated by the PI control algorithm according to the following formula:

[0126] Δ U2i =k p e oi+k i ∫e oi dt

[0127] Among them, Δ U2i is the second load error adjustment of each power module (the second load error adjustment of the i-th power module, i represents the i-th power module), kp and ki are proportional gain and integral gain respectively, e oi is the output power error between the expected output power and the actual output power of the i-th power module.

[0128] For example, Figure 2 As shown in , the output power errors between the expected output power and the actual output power of the two power modules connected in parallel are calculated as e o1 and e o2 , the load error adjustment of the two power modules in parallel is calculated by PI control algorithm and is Δ U21 and Δ U22 .

[0129] The control unit 130 is used to perform load distribution control of each power module in the parallel power supply system according to the second load error adjustment amount of each power module determined by the second calculation unit.

[0130] In a specific embodiment, load distribution control of each power module in the parallel power supply system is performed according to a preset control logic and based on the first load error adjustment amount of each power module and the second load error adjustment amount of each power module obtained by load distribution of the parallel power supply system using current equalization control.

[0131] For example, Figure 2 As shown in the figure, the expected output power of the two power modules connected in parallel is calculated to be p o1,ref ,p o2,ref After that, the output power errors between the expected output power and the actual output power of the two power modules in parallel are calculated as e o1 and e o2 ,, the second load error adjustment values ​​of the two power modules in parallel are obtained by using the PI control algorithm: U21 and Δ U22 The first load error adjustment values ​​of the two parallel power modules obtained by the current sharing control algorithm are Δ U11 and Δ U12 According to the preset control logic (composite control logic), the first load error adjustment value Δ of the two power modules connected in parallel is U11 and Δ U12 and the second load error adjustment Δ U21 and Δ U22Get the load sharing output control quantity Δ of the two power modules in parallel U1 and Δ U2 .

[0132] In a specific implementation, the preset control logic includes: determining the load distribution Δ of each power module according to the following formula: Ui Output control quantity:

[0133] Δ Ui =KΔ U2i +(1-K)Δ U1i

[0134] According to the load distribution of each power module, the output control quantity Δ Ui Perform load distribution control on each power module of the parallel power supply system.

[0135] Among them, Δ Ui The output control amount for each power module load distribution is the load error adjustment amount, Δ U1i is the first load error adjustment amount of each power module, the first load error adjustment amount of each power module is the load error adjustment amount of each power module obtained by using current sharing control to distribute the load of the parallel power system, Δ U2i is the second load error adjustment amount of each power module, K is the switching coefficient, and when the parallel power supply system reaches a steady state, whether K is equal to 1 is determined every first preset time, and if K is not equal to 1, K=K+Kstep, until K=1.

[0136] Specifically, the load distribution control of each power module of the parallel power system is performed according to the value of the switching coefficient K at every second preset time. That is, the load distribution Δ of each power module is determined according to the above formula. Ui Output control amount: the first preset time and the second preset time may be the same or different.

[0137] The change logic of K can be as follows Figure 6 As shown, when the system has not reached a steady state, K = 0. When the system changes to a steady state, the switching coefficient K slowly changes to 1, and the change speed is determined by the preset step length K. step The load distribution result is determined by the efficiency optimization scheduler; when the parallel power system reaches a steady state, it is determined whether K is equal to 1. If K is not equal to 1, then K = K + Kstep, and continue to determine whether K is equal to 1 until K = 1, and then it ends. When the system exits the steady state, the switching coefficient immediately becomes 0, and the load distribution result is determined by the current sharing controller.

[0138] Optionally, the control unit 130 is further used to: when the parallel power supply system has not reached a steady state, use current sharing control to perform load distribution of the parallel power supply system to obtain a first load error adjustment amount for each of the power supply modules; and perform load distribution control of each of the power supply modules in the parallel power supply system based on the obtained first load error adjustment amount for each of the power supply modules.

[0139] Specifically, the power module with the largest output power is selected from all power modules as the main module, and the power of all power modules follows the maximum power Pmax, that is, the expected power of all power modules is Pmax. Then, the first load error adjustment amount can be obtained according to the PI controller.

[0140] The situation in which the parallel power supply system has not reached a steady state includes, for example, the startup process of the parallel power supply system or the load mutation process of the parallel power supply system, that is, during the startup process of the parallel power supply system or the load mutation process of the parallel power supply system, current equalization control is used to distribute the load of the parallel power supply system. Specifically, the parallel power supply system includes a current equalization controller for performing current equalization control on the parallel power supply system. The current equalization controller uses the maximum current equalization method to perform current equalization control. The maximum current equalization method is used to select the power supply module with the largest current from all the power supply modules in the parallel power supply system as the main power supply module, and perform current equalization control on the entire parallel power supply system. Compared with other current equalization control methods, the maximum current equalization method has good reliability. The load distribution of the parallel power supply system is performed using current equalization control, and the load error adjustment amount of each power supply module is obtained, which is recorded as the first load error adjustment amount Δ of each power supply module. U1i .For example, Figure 2 The first load error adjustment amounts of the two power modules connected in parallel are Δ U11 and Δ U12 .

[0141] The present invention also provides a storage medium corresponding to the power scheduling method of the parallel power supply system, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0142] The present invention also provides a controller corresponding to the power scheduling method of the parallel power supply system, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the aforementioned methods when executing the computer program.

[0143] The present invention also provides a controller corresponding to the power dispatching device of the parallel power supply system, including any of the power dispatching devices of the parallel power supply system described above.

[0144] The present invention also provides a computer program product corresponding to the power scheduling method of the parallel power supply system, including a computer program, and when the computer program is executed by a processor, the steps of any of the aforementioned methods are implemented.

[0145] Based on this, the solution provided by the present invention can greatly improve the overall efficiency of parallel power supplies by calculating the power distribution solution with the best overall efficiency in real time through the efficiency curve of the single power supply module.

[0146] The solution provided by the present invention obtains the efficiency curve of the power module by sampling the efficiency of a single power module, and then solves the load distribution solution with the best parallel power efficiency according to the intelligent heuristic algorithm. The preset composite control logic is adopted to ensure the safety of the dynamic process of the parallel power system and the high efficiency of the steady-state process.

[0147] According to the technical solution of the present invention, power scheduling and allocation based on optimal efficiency in steady state is added, and a composite control logic of current equalization and optimal efficiency is implemented based on steady-state judgment, so as to achieve the use of current equalization control scheme in dynamic process and load distribution with optimal efficiency in steady state.

[0148] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium or transmitted via a computer-readable medium. Other examples and implementations are within the scope and spirit of the present invention and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. In addition, each functional unit may be integrated into a processing unit, each unit may exist physically separately, or two or more units may be integrated into one unit.

[0149] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0150] The units described as separate components may or may not be physically separated, and the components of the control device may or may not be physical units, that is, they may be located in one place or distributed in multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0151] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the relevant technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0152] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A power dispatching method for a parallel power supply system, characterized in that: The parallel power supply system includes more than two power supply modules connected in parallel, and the power scheduling method includes: After the parallel power supply system reaches a steady state, based on the approximate efficiency characteristic curve of each of the two or more power modules, a heuristic optimization algorithm is used to calculate the expected output power of each of the power modules; Calculating a second load error adjustment amount for each of the power modules according to the calculated expected output power of each of the power modules and the actual output power of each of the power modules; According to the determined second load error adjustment amount of each power module, load distribution control of each power module of the parallel power supply system is performed.

2. The method according to claim 1, characterized in that: Also includes: When the parallel power supply system has not reached a steady state, current sharing control is used to distribute the load of the parallel power supply system to obtain a first load error adjustment amount for each of the power supply modules; The load distribution control of each power module in the parallel power supply system is performed according to the obtained first load error adjustment amount of each power module.

3. The method according to claim 1, characterized in that Also includes: Determining whether the parallel power supply system has reached a steady state according to a change in the amplitude of the total load power of the parallel power supply system; When the amplitude change of the total float power of the parallel power system is less than a preset threshold value in N consecutive cycles, the parallel power system reaches a steady state.

4. The method according to any one of claims 1 to 3, characterized in that: Based on the approximate efficiency characteristic curve of each of the two or more power modules, a heuristic optimization algorithm is used to calculate the expected output power of each of the power modules, including: Establishing a system efficiency optimization objective function based on an approximate efficiency characteristic curve of each of the two or more power modules; Using a heuristic optimization algorithm to optimize the established system efficiency optimization objective function to obtain the expected output power of each power module; The heuristic algorithm includes: at least one of a simulated annealing algorithm, a particle swarm algorithm, an ant colony algorithm, and a genetic algorithm.

5. The method according to any one of claims 1 to 3, characterized in that: Calculating a second load error adjustment amount of each power module according to the calculated expected output power of each power module and the actual output power of each power module, including: The second load error adjustment amount of each power module is calculated using the PI control algorithm according to the following formula: Δ U2i =k p e oi +k i ∫e oi dt Δ U2i is the second load error adjustment of the ith power module, kp and ki are proportional gain and integral gain respectively, e oi is the output power error between the expected output power and the actual output power of the i-th power module.

6. The method according to any one of claims 1 to 3, characterized in that: According to the determined second load error adjustment amount of each power module, load distribution control of each power module of the parallel power supply system is performed, including: According to the preset control logic and based on the first load error adjustment amount of each power module and the second load error adjustment amount of each power module obtained by performing load distribution of the parallel power system using current sharing control, load distribution control of each power module of the parallel power system is performed; The preset control logic includes: determining the load distribution output control amount Δ of each power module according to the following formula: Ui : D Ui =KD U2i +(1-K)D U1i Among them, Δ u1i is the first load error adjustment amount of each power module obtained by using current sharing control to distribute the load of the parallel power system, Δ U2i is the second load error adjustment amount for each power module, K is the switching coefficient, and when the parallel power supply system reaches a steady state, it is determined whether K is equal to 1 at a first preset time interval, and if K is not equal to 1, then K=K+Kstep, until K=1, where Kstep is a preset step length.

7. A power dispatching device for a parallel power supply system, characterized in that: The parallel power supply system includes more than two power supply modules connected in parallel, and the power dispatching device includes: A first calculation unit, configured to calculate the expected output power of each of the two or more power modules by using a heuristic optimization algorithm based on an approximate efficiency characteristic curve of each of the two or more power modules after the parallel power supply system reaches a steady state; A second calculation unit, configured to calculate a second load error adjustment amount for each of the power modules according to the expected output power of each of the power modules and the actual output power of each of the power modules calculated by the first calculation unit; A control unit is used to perform load distribution control of each power module in the parallel power supply system according to the second load error adjustment amount of each power module determined by the second calculation unit.

8. A storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the steps of any method described in claims 1-6 are implemented.

9. A controller, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any method described in claims 1 to 6 when executing the program, or comprises the power dispatching device described in claim 7.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the steps of any one of the methods of claims 1 to 6 when executed by a processor.

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