Scheduling direct current power supply system energy management strategy considering time delay correction
By designing an energy management strategy for a dispatchable DC power supply system that considers time delay correction, the problems of sudden bus voltage drop and power distribution deviation caused by sudden increase in time delay in the dispatchable DC power supply system are solved, thereby improving the stability and robustness of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-08
AI Technical Summary
Sudden increases in time delay between units in a dispatchable DC power supply system can lead to a sharp drop in bus voltage and power distribution deviation. Existing methods are not robust enough to deal with sudden changes in time delay and load fluctuations, making it difficult to achieve multi-objective collaborative optimization.
Design an energy management strategy for a schedulable DC power supply system that considers time delay correction. By combining precise power allocation control, a consensus algorithm for time delay correction, and bus voltage drop recovery control with voltage and current dual closed-loop control, the system achieves time delay correction, average power allocation factor solution, and bus voltage recovery.
Simultaneous time delay correction, precise power distribution, and bus voltage recovery are achieved on the same time scale, enhancing system stability, suppressing the effects of time delay abrupt changes, and improving system robustness and dynamic response capabilities.
Smart Images
Figure CN122000854A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of distributed energy storage systems for DC microgrids, and in particular to energy management strategies for dispatchable DC power systems that consider time delay correction. Background Technology
[0002] With the rapid development and widespread application of new energy power generation technologies, dispatchable DC power systems are playing an increasingly prominent role in supporting microgrids and smart distribution networks. They typically need to achieve multiple control objectives, such as precise power allocation and stable bus voltage, to meet the power system's diverse demands for power quality and operational economy. However, the units in dispatchable DC power systems are often deployed in a distributed manner. When these units interact and transmit control commands through communication networks, sudden increases in time delays can easily occur. If this time delay is not effectively corrected in a timely manner, it may lead to a sudden drop in bus voltage and a surge in power allocation deviations. In severe cases, it may induce control failure and ultimately cause system instability. Furthermore, existing methods often rely on traditional droop control in the power allocation stage. This inherently creates a coupling contradiction between voltage drop and power allocation, limiting power allocation accuracy and voltage recovery capability. Moreover, due to the fixed droop coefficient, it lacks robustness and dynamic response in complex operating conditions such as sudden time delays and load fluctuations, making it difficult to simultaneously meet the needs of multi-objective collaborative optimization.
[0003] To address this, the present invention proposes an energy management strategy for a schedulable DC power supply system that considers time delay correction. This strategy can simultaneously achieve the control objectives of time delay correction, average power allocation factor calculation, precise output power allocation, and bus voltage drop recovery of the schedulable DC power supply system on the same time scale. The strategy proposed in this invention can effectively suppress the adverse effects of time delay abrupt changes on the system and enhance the system's operational stability. Summary of the Invention
[0004] To achieve the above objectives, the technical solution provided by this invention is as follows:
[0005] Step 1: After the schedulable DC power supply system starts up, collect the inductor current of the nth schedulable DC power supply. Output voltage Output current n=1,2,3,4…; Step 2: In the coordinated control module of the schedulable DC power supply system, the inductor current of the schedulable DC power supply is... Output voltage Rated voltage As input, after processing by precise power allocation control, a consistency algorithm considering time delay correction, and bus voltage drop recovery control, the output is the bus voltage drop recovery amount. This includes the following steps: Step 2-1: In precise power distribution control, the scalable DC power supply inductor current... Divide by the maximum rated inductor current of the switchable DC power supply Obtain the per-unit value of the inductor current of the schedulable DC power supply. , output voltage Divide by the maximum rated voltage The per-unit value of the output voltage can be obtained. , the rated voltage Divide by the maximum rated voltage The per-unit value of the rated voltage can be obtained. The specific expression is: (1) Per-unit value of the inductor current of the scalable DC power supply With inductor current adjustment coefficient Multiply by each other, then divide the result by the per-unit value of the output voltage. With output voltage regulation coefficient The power allocation factor can be calculated by multiplying the product of the two factors. The rated voltage per unit value; With rated voltage regulation coefficient Multiply them, then subtract the per-unit value of the inductor current from the result. With inductor current adjustment coefficient The power allocation error can be calculated by multiplying the product of the two factors. Power allocation factor and power distribution error The specific expression is: (2) Step 2-2: Apply the power allocation factor generated in Step 2-1 As input, after processing by a consensus algorithm that takes time delay correction into account, the average power allocation factor of the nth schedulable DC power source can be calculated. The specific expression is: (3) In equation (3), For consistency weight, The summation index represents any adjacent schedulable DC power source of the nth schedulable DC power source. Let be the set of adjacent nodes of the nth schedulable DC power supply. Let be the average power allocation factor of the j-th dispatchable DC power supply. For the Laplace operator, For the time delay between schedulable DC power sources, For the time delay correction stage, the specific expression is: (4) In equation (4), This is the time delay correction factor. The correlation coefficient of the average power allocation factor. It is a time constant. The time delay is the response time. Steps 2-3: In the bus voltage drop recovery control, adjust the average power distribution factor of the nth dispatchable DC power supply. Subtract power distribution error The sine value is obtained, and the result is then processed by the PI controller in the bus voltage drop recovery stage to obtain the bus voltage drop recovery amount. The specific expression is: (5) In equation (5), and These are the proportional and integral coefficients of the PI controller in the bus voltage drop recovery circuit, respectively. Step 3: In the voltage and current dual closed-loop control module, the bus voltage drop recovery amount is... Adjustable DC power supply inductor current Output voltage Rated voltage and output current As input, after voltage and current dual closed-loop control and PWM modulation, a modulated signal can be output. To control the switching on and off of the schedulable DC power supply.
[0006] Furthermore, in step 2, the inductor current adjustment coefficient The range of values is 0 < <3, Output voltage regulation coefficient The range of values is 0 < <1, rated voltage regulation coefficient The value range is 0.4 < <1.2, time delay correction factor The value range is 20< <40, average power allocation factor correlation coefficient The value range is 0.5 < <2.5, time constant The value range is 0.003 < <0.03, time delay response time The value range is 0.0005 < <0.005, the proportional coefficient of the PI controller in the bus voltage drop recovery circuit. The value range is 0.5 < <2, Integral coefficient of the PI controller in the bus voltage drop recovery circuit The value range is 12< <25.
[0007] Compared with existing technologies, the principles and advantages of this solution are as follows: This invention discloses an energy management strategy for a dispatchable DC power supply system that considers time delay correction. It mainly includes a dispatchable DC power supply system collaborative control module and a voltage and current dual closed-loop module. Through a single dispatchable DC power supply system collaborative control module, which integrates precise power allocation control, a consensus algorithm considering time delay correction, and bus voltage drop recovery control, the control objectives of time delay correction, average power allocation factor calculation, precise output power allocation, and bus voltage drop recovery can be achieved simultaneously on the same time scale. This invention can effectively suppress the adverse effects of sudden changes in system time delay and enhance system operational stability. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the topology of the schedulable DC power supply system and the energy management strategy of the schedulable DC power supply system with time delay correction in an embodiment of the present invention. Figure 2 This is a block diagram of the coordinated control of the schedulable DC power supply system in an embodiment of the present invention; Figure 3 The conventional method in the embodiments of the present invention addresses the following: Waveform of DC bus voltage during a sudden increase; Figure 4 The method of the present invention in the embodiments of the present invention should be adapted to Waveform of DC bus voltage during a sudden increase; Figure 5 The conventional method in the embodiments of the present invention addresses the following: Output power waveform during a sudden increase; Figure 6 The method of the present invention in the embodiments of the present invention should be adapted to Output power waveform during a sudden increase; Figure 7 The waveform diagram shows the time delay correction effect in an embodiment of the present invention. Detailed Implementation
[0009] The present invention will be further described below with reference to specific embodiments: Figure 1 The diagram shows the topology of a schedulable DC power supply system and a schematic diagram of coordinated control of a schedulable DC power supply system with time delay correction. Figure 2 The diagram shown is a block diagram of the coordinated control of a dispatchable DC power supply system, including the following steps: Step 1: After the schedulable DC power supply system starts up, collect the inductor current of the nth schedulable DC power supply. Output voltage Output current n=1,2,3,4…; Step 2: In the coordinated control module of the schedulable DC power supply system, the inductor current of the schedulable DC power supply is... Output voltage Rated voltage As input, after processing by precise power allocation control, a consistency algorithm considering time delay correction, and bus voltage drop recovery control, the output is the bus voltage drop recovery amount. This includes the following steps: Step 2-1: In precise power distribution control, the scalable DC power supply inductor current... Divide by the maximum rated inductor current of the switchable DC power supply Obtain the per-unit value of the inductor current of the schedulable DC power supply. , output voltage Divide by the maximum rated voltage The per-unit value of the output voltage can be obtained. , the rated voltage Divide by the maximum rated voltage The per-unit value of the rated voltage can be obtained. The specific expression is: (6) Per-unit value of the inductor current of the scalable DC power supply With inductor current adjustment coefficient Multiply by each other, then divide the result by the per-unit value of the output voltage. With output voltage regulation coefficient The power allocation factor can be calculated by multiplying the product of the two factors. The rated voltage per unit value; With rated voltage regulation coefficient Multiply them, then subtract the per-unit value of the inductor current from the result. With inductor current adjustment coefficient The power allocation error can be calculated by multiplying the product of the two factors. Power allocation factor and power distribution error The specific expression is: (7) Step 2-2: Apply the power allocation factor generated in Step 2-1 As input, after processing by a consensus algorithm that takes time delay correction into account, the average power allocation factor of the nth schedulable DC power source can be calculated. The specific expression is: (8) In equation (8), For consistency weight, The summation index represents any adjacent schedulable DC power source of the nth schedulable DC power source. Let be the set of adjacent nodes of the nth schedulable DC power supply. Let be the average power allocation factor of the j-th dispatchable DC power supply. For the Laplace operator, For the time delay between schedulable DC power sources, For the time delay correction stage, the specific expression is: (9) In equation (9), This is the time delay correction factor. The correlation coefficient of the average power allocation factor. It is a time constant. The time delay is the response time. Steps 2-3: In the bus voltage drop recovery control, adjust the average power distribution factor of the nth dispatchable DC power supply. Subtract power distribution error The sine value is obtained, and the result is then processed by the PI controller in the bus voltage drop recovery stage to obtain the bus voltage drop recovery amount. The specific expression is: (10) In equation (10), and These are the proportional and integral coefficients of the PI controller in the bus voltage drop recovery circuit, respectively. Step 3: In the voltage and current dual closed-loop control module, the bus voltage drop recovery amount is... Adjustable DC power supply inductor current Output voltage Rated voltage and output current As input, after voltage and current dual closed-loop control and PWM modulation, a modulated signal can be output. To control the switching on and off of the schedulable DC power supply.
[0010] Furthermore, in step 2, the inductor current adjustment coefficient The range of values is 0 < <3, Output voltage regulation coefficient The range of values is 0 < <1, rated voltage regulation coefficient The value range is 0.4 < <1.2, time delay correction factor The value range is 20< <40, average power allocation factor correlation coefficient The value range is 0.5 < <2.5, time constant The value range is 0.003 < <0.03, time delay response time The value range is 0.0005 < <0.005, the proportional coefficient of the PI controller in the bus voltage drop recovery circuit. The value range is 0.5 < <2, Integral coefficient of the PI controller in the bus voltage drop recovery circuit The value range is 12< <25.
[0011] Figure 3 and Figure 4 The traditional method and the method of the present invention are respectively used to address the problem. The waveform of the DC bus voltage during a sudden increase. Four dispatchable DC power supplies are connected in parallel via a DC / DC converter to form a dispatchable DC power supply system, and simulation analysis is performed. The topology parameters of the dispatchable DC power supply system are set as follows: filter inductor... All are set to 0.0025H, the line resistance of the four adjustable DC power supplies. The interconnection line resistances between the four adjustable DC power supplies are set to 0.2Ω, 0.25Ω, 0.3Ω, and 0.35Ω respectively. , , , The resistance values were set to 0.2Ω, 0.23Ω, 0.26Ω, and 0.3Ω respectively, with loads... to Set to 12.75kW, rated voltage Set to 400V; regarding control parameters, the inductor current adjustment coefficient... Set to 2, output voltage regulation coefficient Set to 0.5, rated voltage regulation coefficient Set to 1, the proportional coefficient of the PI controller in the bus voltage drop recovery circuit. Set to 0.8, the integral coefficient of the PI controller in the bus voltage drop recovery circuit. Set to 22; in terms of simulation conditions, when the system is set to 8 seconds, the time delay is... The initial value was suddenly increased from 1ms to 100ms, and the simulation continued until its end. The control parameters after incorporating the method of this invention are as follows: =0.8, =0.6, = 1.1, =30, =1.5, =0.008, =0.001. Figure 3 and Figure 4 The adjustments and parameter settings for both simulations were kept consistent. Figure 3 It can be seen that when using the existing traditional control strategy, there is a drop in bus voltage at the beginning of the system startup, which recovers to around the rated voltage of 400V in about 6 seconds. After the system has been running for 8 seconds, The sudden increase in voltage caused the system's bus voltage drop recovery capability to gradually deteriorate, leading to a voltage drop. At 12.4 seconds, the bus voltage dropped to 250V, at which point the system became unstable, with the bus voltage experiencing violent oscillations and unable to recover to near its rated value. (Comparison) Figure 4 After adopting the method of this invention, there is a certain voltage fluctuation when the system is first started, but it recovers to the rated voltage of around 400V within 0.6s, and when the system runs for 8s, T m In the event of a sudden voltage spike, the method described in this invention resulted in only a minor fluctuation of 0.8V in the bus voltage, which recovered to the rated value within 0.8 seconds and subsequently maintained stable operation near the rated voltage of 400V. Figure 3 and Figure 4 In a direct comparison, compared with existing traditional methods, the method proposed in this invention has superior performance and faster response rate in the bus voltage recovery stage; more importantly, this invention can effectively suppress the sudden drop in bus voltage caused by time delay, thereby avoiding the risk of system instability caused by it.
[0012] Figure 5 and Figure 6 The traditional method and the method of the present invention are respectively used to address the problem. Output power waveform during a sudden increase. Figure 3 , Figure 4 The bus voltage variation shown is related to Figure 5 , Figure 6 The output power variation shown corresponds to the same simulation conditions and parameters. Figure 5 It can be seen that when using the existing traditional control strategy, there is a significant deviation in the output power distribution at the beginning of the system startup, which gradually begins to converge. When the system has been running for 8 seconds, T mThe sudden increase in power distribution caused the system's ability to precisely allocate power to gradually deteriorate, leading to a rapid increase in output power distribution deviation. After 12.4 seconds, the output power distribution deviation experienced a sudden surge, causing system instability. The output power of each schedulable DC power source oscillated violently and could no longer achieve precise distribution. (Comparison) Figure 6 After adopting the method of this invention, although there was a certain deviation in the output power distribution at the beginning of the system startup, precise output power distribution was achieved in about 5 seconds. The output power of the four schedulable DC power supplies was maintained at around 12.75kW, and when the system ran for 8 seconds, Even with a sudden increase, the output power of each schedulable DC power source remains precisely allocated after adopting the method of this invention until the system runs to the end of the simulation. Figure 5 and Figure 6 In a direct comparison, the method of the present invention has a faster and more accurate power allocation capability than existing traditional methods. More importantly, the method proposed in this invention can effectively suppress the instantaneous surge in output power allocation deviation caused by time delay, thereby avoiding the risk of system instability caused by it.
[0013] Figure 7 This is a waveform diagram showing the effect of time delay correction. Figure 7 As can be seen, compared with the prior art, the method proposed in this invention can not only more accurately track the dynamic process of sudden increase in time delay and respond to compensation more quickly, but also produce better waveforms of bus voltage and output power after compensation, which fully demonstrates the effectiveness of this method in suppressing time delay. Effectiveness in terms of the effects of mutations.
[0014] As can be seen from the above analysis, the present invention designs an energy management strategy for a dispatchable DC power supply system that considers time delay correction. By designing a coordinated control of the dispatchable DC power supply system, the control objectives of time delay correction, average power allocation factor solution, accurate output power allocation, and bus voltage drop recovery of the dispatchable DC power supply system can be achieved synchronously on the same time scale. The strategy proposed in this invention can effectively suppress the adverse effects of time delay mutations on the system and enhance the system's operational stability.
[0015] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any changes made in accordance with the shape and principle of the present invention should be covered within the protection scope of the present invention.
Claims
1. An energy management strategy for a schedulable DC power supply system considering time delay correction, characterized in that, Includes the following steps: Step 1: After the schedulable DC power supply system starts up, collect the inductor current of the nth schedulable DC power supply. Output voltage Output current n=1,2,3,4…; Step 2: In the coordinated control module of the schedulable DC power supply system, the inductor current of the schedulable DC power supply is... Output voltage Rated voltage As input, after processing by precise power allocation control, a consistency algorithm considering time delay correction, and bus voltage drop recovery control, the output is the bus voltage drop recovery amount. This includes the following steps: Step 2-1: In precise power distribution control, the scalable DC power supply inductor current... Divide by the maximum rated inductor current of the switchable DC power supply Obtain the per-unit value of the inductor current of the schedulable DC power supply. , output voltage Divide by the maximum rated voltage The per-unit value of the output voltage can be obtained. , the rated voltage Divide by the maximum rated voltage The per-unit value of the rated voltage can be obtained. The specific expression is: (1) Per-unit value of the inductor current of the scalable DC power supply With inductor current adjustment coefficient Multiply by each other, then divide the result by the per-unit value of the output voltage. With output voltage regulation coefficient The power allocation factor can be calculated by multiplying the product of the two factors. The rated voltage per unit value; With rated voltage regulation coefficient Multiply them, then subtract the per-unit value of the inductor current from the result. With inductor current adjustment coefficient The power allocation error can be calculated by multiplying the product of the two factors. Power allocation factor and power distribution error The specific expression is: (2) Step 2-2: Apply the power allocation factor generated in Step 2-1 As input, after processing by a consensus algorithm that takes time delay correction into account, the average power allocation factor of the nth schedulable DC power source can be calculated. The specific expression is: (3) In equation (3), For consistency weight, The summation index represents the sum of any adjacent schedulable DC power sources of the nth schedulable DC power source. Let n be the set of adjacent nodes of the nth schedulable DC power supply. Let be the average power allocation factor of the j-th dispatchable DC power supply. For the Laplace operator, For the time delay between schedulable DC power sources, For the time delay correction stage, the specific expression is: (4) In equation (4), This is the time delay correction factor. The correlation coefficient of the average power allocation factor. It is a time constant. The time delay is the response time. Steps 2-3: In the bus voltage drop recovery control, adjust the average power distribution factor of the nth dispatchable DC power supply. Subtract power distribution error The sine value is obtained, and the result is then processed by the PI controller in the bus voltage drop recovery stage to obtain the bus voltage drop recovery amount. The specific expression is: (5) In equation (5), and These are the proportional and integral coefficients of the PI controller in the bus voltage drop recovery circuit, respectively. Step 3: In the voltage and current dual closed-loop control module, the bus voltage drop recovery amount is... Adjustable DC power supply inductor current Output voltage Rated voltage and output current As input, after voltage and current dual closed-loop control and PWM modulation, a modulated signal can be output. To control the switching on and off of the schedulable DC power supply.
2. The energy management strategy for a schedulable DC power supply system considering time delay correction according to claim 1, characterized in that, In step 2, the inductor current adjustment coefficient The range of values is 0 < <3, Output voltage regulation coefficient The range of values is 0 < <1, rated voltage regulation coefficient The value range is 0.4 < <1.2, time delay correction factor The value range is 20< <40, average power allocation factor correlation coefficient The value range is 0.5 < <2.5, time constant The value range is 0.003 < <0.03, time delay response time The value range is 0.0005 < <0.005, the proportional coefficient of the PI controller in the bus voltage drop recovery circuit. The value range is 0.5 < <2, Integral coefficient of the PI controller in the bus voltage drop recovery circuit The value range is 12< <25.