Busbar voltage supporting method and terminal equipment for energy-storage-free type photovoltaic-diesel direct-current micro-grid

Abstract

The invention discloses a non-energy-storage type photovoltaic-diesel direct current micro-grid bus voltage supporting method and terminal equipment, and the method comprises the steps: setting voltage-power droop coefficients of a photovoltaic module and a diesel generator module, improving the output ratio of the photovoltaic module in a whole system through virtual power, and improving the utilization rate of the photovoltaic module; meanwhile, in order to improve the supporting capacity of the system for bus voltage during load switching, a bus voltage compensation method is designed, by detecting the bus voltage and the output current of the photovoltaic module and the diesel generator module, through mode judgment and output selection, the state of the system switching on or switching off the load is detected, and the system switching on or switching off the load is achieved. And a bus voltage compensation signal is formed according to the current output states of the photovoltaic module and the diesel generator module, and is superposed on a voltage outer ring of a photovoltaic module and diesel generator module control system, so that the active support capability of the system is improved, and the safe operation level of the system under the switching load is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of micro-source interconnected power supply and control technology, and in particular to a bus voltage support method and terminal equipment for a non-energy storage type photovoltaic-diesel DC microgrid. Background Art

[0002] The DC microgrid composed of photovoltaic power generation, energy storage system and diesel generator provides a reliable solution to the current shortage of traditional fossil energy and environmental pollution. Especially in remote areas, photovoltaic-diesel-storage DC microgrid is widely used due to its high reliability and simple control (compared with AC microgrid). The existing photovoltaic-diesel-storage DC microgrid uses photovoltaic power generation in MPPT mode to maximize benefits, diesel generators as current sources to supplement the system output power shortage, and energy storage batteries as voltage sources to establish bus voltage and use energy storage charging and discharging characteristics to maintain system power balance. However, when the SOC of the energy storage battery is too high to continue charging or the SOC is too low or even damaged to maintain the bus voltage, if the photovoltaic module and the diesel generator module continue to maintain the conventional control mode, the bus voltage will be unstable. The unidirectional source characteristics of the photovoltaic module and the diesel generator module will cause system power imbalance. In severe cases, the converter will be damaged and the system will be disconnected.

[0003] Therefore, a control system is needed for the stable operation of a photovoltaic-diesel DC microgrid in a scenario without energy storage, including a photovoltaic-diesel parallel droop system and a fast compensation method for the drastic changes in bus voltage when the system switches on and off the load, to ensure the stable operation of the system on the one hand and the maximization of photovoltaic benefits on the other. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a bus voltage support method and terminal equipment for a photovoltaic-diesel DC microgrid without energy storage in view of the shortcomings of the existing technology, so as to ensure that the photovoltaic-diesel-storage DC microgrid can still maintain stable operation and maximize photovoltaic benefits in a scenario without energy storage.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a bus voltage support method for a non-storage solar-diesel DC microgrid, wherein the non-storage solar-diesel DC microgrid comprises a photovoltaic module and a diesel generator module, wherein both the photovoltaic module and the diesel generator module are connected to the DC bus; and the method comprises the following steps:

[0006] S1, the sampled bus voltage signal u bus The high-frequency component u of the bus voltage is obtained by high-pass filter H(s) m ;

[0007] The bus voltage signal u bus The sampled photovoltaic module output current i o_pv , Diesel generator module output current io_dg Multiply them together to get the photovoltaic module output power p o_pv The output power of the diesel generator module o_dg ;

[0008] S2. For photovoltaic modules, when u m <x1&&Δu pv <0, in the first stage of loading, compensation coefficient m pv =n pv1 (P pv -p o_pv ), where P pv is the rated capacity of the photovoltaic module, n pv1 is the coefficient constant of the first stage of input load; when u m >0&&Δu pv <0, in the second stage of loading, compensation coefficient m pv =n pv2 (P pv -p o_pv ), where n pv2 is the second stage coefficient constant of the input load; when u m >x2&&Δu pv >0, in the first stage of load shedding, compensation coefficient m pv =n pv3 p o_pv , where n pv3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu pv >0, in the second stage of load shedding, compensation coefficient m pv =n pv4 p o_pv , where n pv4 is the coefficient constant of the second stage of load shedding; x1 and x2 are the lower and upper limits of the high-frequency component of the bus voltage in steady state respectively; Δu pv is the bus voltage control reference value U of the photovoltaic module ref_pv The actual value of busbar u bus difference;

[0009] For the diesel generator module, when u m <x1&&Δu dg <0, in the first stage of loading, compensation coefficient m dg =n dg1 (P dg -p o_dg ), where P dg is the rated capacity of the diesel generator module, n dg1 is the coefficient constant of the first stage of input load; when u m >0&&Δu dg<0, in the second stage of loading, compensation coefficient m dg =n dg2 (P dg -p o_dg ), where n dg2 is the second stage coefficient constant of the input load, when u m >x2&&Δu dg >0, in the first stage of load shedding, compensation coefficient m dg =n dg3 p o_dg , where n dg3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu dg >0, in the second stage of load shedding, compensation coefficient m dg =n dg4 p o_dg , where n pv4 Δu is the coefficient constant of the second stage of load shedding; dg The bus voltage control reference value U of the diesel generator module ref_dg The actual value of busbar u bus difference;

[0010] S3, the high frequency component of bus voltage u m Multiply by the photovoltaic module compensation coefficient m pv Compensation coefficient m dg , respectively obtain the bus voltage compensation component u of the photovoltaic module cpv The bus voltage compensation component u of the diesel generator module cdg , which are superimposed on the voltage outer loop of the photovoltaic module and diesel generator module control system for compensation.

[0011] The present invention supports the bus voltage when the load is switched according to the current output states of the photovoltaic module and the diesel generator module, thereby avoiding over-compensation and under-compensation of the system when the load is switched, thereby reducing the possibility of dynamic instability of the system.

[0012] The method of the present invention further comprises:

[0013] Calculate the reference value U of the PV module bus voltage pv The U of the diesel generator module bus voltage dg ; The reference value U of the photovoltaic module bus voltage pv The bus voltage compensation component u of the photovoltaic module cpv Add them together to get the given value U of the PV module voltage outer loop. ref_pv ; The reference value U of the diesel generator module bus voltage dg The bus voltage compensation component u of the diesel generator module cdg Add them together to get the given value U of the diesel generator module voltage outer loopref_dg ;

[0014] The photovoltaic module voltage outer loop given value U ref_pv With bus voltage signal u bus Make a difference and get the photovoltaic module voltage deviation signal Δu pv ; Set the diesel generator module voltage outer loop given value U ref_dg With bus voltage signal u bus Make a difference and get the voltage deviation signal Δu of the diesel generator module dg ;

[0015] The photovoltaic module voltage deviation signal Δu pv Through the voltage outer loop PI controller G cv_pv , get the photovoltaic module current inner loop given value I ref_pv ; The diesel generator module voltage deviation signal Δu dg Through the voltage outer loop PI controller G cv_dg , to the diesel generator module current inner loop given value I ref_dg ;

[0016] The photovoltaic module current inner loop given value I ref_pv The output current of the photovoltaic module is o_pv Make a difference and get the photovoltaic module current deviation signal Δi pv ; Set the diesel generator module current inner loop given value I ref_dg The input current i in_dg Make a difference and get the current deviation signal Δi of the diesel generator module dg ;

[0017] The photovoltaic module current deviation signal Δi pv , Diesel generator module current deviation signal Δi dg Through the current inner loop PI controller G ci_pv , G ci_dg , corresponding to the PWM modulation signal of the photovoltaic module and the PWM modulation signal of the diesel generator module.

[0018] The above implementation process adopts a control strategy of voltage and current double closed loop and compensation component superposition. By controlling voltage and current at the same time, the superposition of double closed loop control and compensation can effectively cope with load changes and system disturbances, and improve the dynamic response capability and stability of the system. The current loop is usually used to quickly respond to load changes, while the voltage loop is used to stabilize the long-term output voltage, and the compensation is used to quickly respond to load changes.

[0019] In the present invention, V o It is the output voltage of the photovoltaic-diesel DC microgrid without energy storage when both the photovoltaic module and the diesel generator module are running at no load.

[0020] The output ratio of the photovoltaic module and the diesel module is in, where k pv is the photovoltaic droop curve, power coefficient a>>1, P pv is the rated capacity of the photovoltaic module, P dg is the rated capacity of the diesel generator module, V0 and V1 are the rated value and lower limit of the bus voltage respectively, k dg =(V0-V1) / -P dg In the present invention, the line impedance is not considered, and the output ratio of the photovoltaic module and the diesel generator module is determined by the k in the conventional droop curve. dg :k pv , becomes The output ratio of photovoltaic modules in the system is greatly improved.

[0021] As an inventive concept, the present invention also provides a terminal device, which includes:

[0022] one or more processors;

[0023] A memory having one or more programs stored thereon, which, when executed by the one or more processors, enables the one or more processors to implement the steps of the above method.

[0024] As an inventive concept, the present invention also provides a computer-readable storage medium storing a computer program, which implements the steps of the above method when executed by a processor.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) In the case of a solar-diesel DC microgrid without energy storage, the present invention designs a solar-diesel droop control system based on virtual power, so that the photovoltaic module works as a voltage source while maintaining a large output share in the solar-diesel parallel system, thereby ensuring the maximization of the economic benefits of the photovoltaic module and better saving traditional fossil energy;

[0027] 2) Compared with conventional DC microgrids that complete energy scheduling based on communication, the photovoltaic module and the diesel generator module adopt a droop control system, which does not require an additional communication module to complete the energy coordination between the photovoltaic and diesel generator modules. This not only ensures that there is no control stability interference caused by communication delay, but also greatly saves costs.

[0028] 3) The bus voltage compensation coefficient in the present invention is designed based on the current output power and remaining capacity of the photovoltaic module and the diesel generator module. At the same time, the bus voltage is divided into two stage modes according to the state of load switching, which conforms to the actual working characteristics and avoids bus voltage instability caused by over-compensation and under-compensation. At the same time, because the compensation amount is added to the control system voltage outer loop, the compensation amount is zero in steady state, which will not affect the steady-state operation of the drooping system of the photovoltaic module and the diesel generator module, greatly improving the response speed and stable operation level of the photovoltaic-diesel DC microgrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is an overall control block diagram of the bus voltage support method for a photovoltaic-diesel DC microgrid without energy storage implemented in the present invention;

[0030] Figure 2 A graph showing a solar-diesel droop system based on virtual power implemented in the present invention;

[0031] Figure 3 The control block diagram of the bus voltage compensation method for photovoltaic modules and diesel generator modules implemented in the present invention; (a) control block diagram of the bus voltage compensation method for photovoltaic modules; (b) control block diagram of the bus voltage compensation method for diesel generator modules;

[0032] Figure 4 The main simulation waveforms of the bus voltage support method for the non-energy storage photovoltaic-diesel DC microgrid implemented in the present invention; (a) the output current waveforms of the photovoltaic module and the diesel generator module; (b) the load bus voltage waveform when no compensation is added; (c) the load bus voltage waveform when compensation is added. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1As shown, the embodiment of the present invention is based on virtual power and a droop control system and bus voltage compensation method for a photovoltaic-diesel DC microgrid without energy storage. The photovoltaic panel is connected to the DC bus via a DC / DC converter, and the diesel generator is connected to the DC bus via an uncontrolled rectifier and a DC / DC converter. The photovoltaic module and the diesel generator module (diesel generator) both introduce a droop system based on the voltage and current double closed-loop control. In order to increase the output proportion of the photovoltaic module in the system and maximize the photovoltaic benefit, virtual power is introduced to it. At the same time, in order to improve the active support capability of the photovoltaic-diesel system for the bus voltage when switching on and off the load, both introduce bus voltage compensation control to improve the stability of the system under load impact.

[0036] Figure 1 This is a flow chart of a droop control system and bus voltage compensation method for a photovoltaic-diesel DC microgrid without energy storage based on virtual power in an embodiment of the present invention. The specific operation steps include:

[0037] The sampled bus voltage u bus Multiply the sampled output current i of the photovoltaic and diesel generator modules respectively o_pv ,i o_dg Get the output power p of the photovoltaic and diesel modules o_pv , p o_dg , the reference value of bus voltage U is obtained through the droop system of photovoltaic module and diesel generator module pv , U dg , p o_pv , p o_dg Substituting the power-voltage droop curve expressions of the photovoltaic module and the diesel generator module, Get the reference value U of bus voltage pv , U dg , plus the bus voltage compensation u cpv ,u cdg , get the voltage outer loop given value U of the photovoltaic and diesel generator modules ref_pv , U ref_dg , set the voltage external loop of the photovoltaic module and the diesel generator module to the given value U ref_pv , U ref_dg Respectively with the sampled u bus Make a difference and get the voltage deviation signal Δu pv , Δu dg , and then through the voltage outer loop PI controller G cv_pv , G cv_dg Get the inner loop current given value I of the photovoltaic module and diesel generator module ref_pv , I ref_dg ,in Set the current inner loop of the photovoltaic module and the diesel generator module to the given value I ref_pv , I ref_dg The sampled photovoltaic module output current i o_pv , Diesel generator module input current iin_dg Make a difference and get the current deviation signal Δi pv , Δi dg , and then through the current inner loop PI controller G ci_pv , G ci_dg Get the PWM modulation signal of photovoltaic module and diesel generator module

[0038] like Figure 2 As shown, the photovoltaic-diesel droop system based on virtual power in the embodiment of the present invention introduces virtual power on the basis of the conventional droop control method (such as the droop control method in "A Review of Research on Key Technologies of DC Microgrids" published by Li Xialin, Guo Li, Wang Chengshan et al. in "High Voltage Technology" No. 1, 2016, pp. 2-17). The power upper limit of the photovoltaic module voltage-power droop curve is increased by virtual power, and the line impedance is not considered. The output ratio of the photovoltaic module and the diesel generator module is changed from k in the conventional droop curve to k. dg :k pv , becomes Greatly improve the output ratio of photovoltaic modules in the system, among which k pv =(V0-V1) / -P pv , k dg =(V0-V1) / -P dg , Where V0 and V1 are the rated value and lower limit of the bus voltage, a>>1, thereby maximizing the benefit of the photovoltaic module.

[0039] like Figure 3 As shown in the control block diagram of the bus voltage compensation method of the embodiment of the present invention, the specific implementation steps are as follows: Calculate the high-frequency component u of the bus voltage when the photovoltaic module and the diesel generator module are switched on and off m :The sampled bus voltage signal u bus The high-frequency component u of the bus voltage is obtained by high-pass filter H(s) m ,in Where ωC is the cutoff frequency of the high-pass filter, and the sampled bus voltage u bus , and the sampled output current i of the photovoltaic module and the diesel generator module o_pv ,i o_dg Multiply them respectively to get the output power p of the photovoltaic module and the diesel generator module o_pv , p o_dg , set the lower limit of the high-frequency component of the bus voltage in steady state to x1 and the upper limit to x2, and set the high-frequency component of the bus voltage u m The bus voltage control reference value U of the photovoltaic module and the diesel generator module ref_pv , U ref_dg The actual value of busbar u bus The difference Δu pv, Δu dg The voltage judgment function n of the photovoltaic module and the diesel generator module is pv (u m ,Δu),n dg (u m ,Δu), for photovoltaic modules, when u m <x1&&Δu pv <0(&& indicates u m <x1、Δu pv <0, both conditions must be met), the system is in the first stage of loading, the compensation coefficient m pv =n pv1 (P pv -p o_pv ), where P pv is the rated capacity of the photovoltaic module, n pv1 is the first stage coefficient constant of the input load, when u m >0&&Δu pv <0, the system is in the second stage of loading, the compensation coefficient m pv =n pv2 (P pv -p o_pv ), where n pv2 is the second stage coefficient constant of the input load, when u m >x2&&Δu pv >0, the system is in the first stage of load shedding, the compensation coefficient m pv =n pv3 p o_pv , where n pv3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu pv >0, the system is in the second stage of load shedding, the compensation coefficient m pv =n pv4 p o_pv , where n pv4 is the second stage coefficient constant of load shedding. For the diesel generator module, when u m <x1&&Δu dg <0, the system is in the first stage of loading, the compensation coefficient m dg =n dg1 (P dg -p o_dg ), where P dg is the rated capacity of the diesel generator module, n dg1 is the first stage coefficient constant of the input load, when u m >0&&Δu dg <0, the system is in the second stage of loading, the compensation coefficient m dg =n dg2 (Pdg -p o_dg ), where n dg2 is the second stage coefficient constant of the input load, when u m >x2&&Δu dg >0, the system is in the first stage of load shedding, the compensation coefficient m dg =n dg3 p o_dg , where n dg3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu dg >0, the system is in the second stage of load shedding, the compensation coefficient m dg =n dg4 p o_dg , where n pv4 is the coefficient constant of the second stage of load removal; when the photovoltaic module and the diesel generator module enter the compensation, the compensation coefficient m at this time pv , m dg The compensation coefficient is locked to keep unchanged until the high-frequency component of the bus voltage returns to the threshold range and stabilizes for a period of time. m Multiply by the photovoltaic module compensation coefficient m pv Compensation coefficient m dg , forming the bus voltage compensation component u cpv ,u cdg , which are superimposed on the voltage outer loop of the photovoltaic module and diesel generator module control system for compensation.

[0040] like Figure 4 As shown in the figure, the main simulation waveforms of the droop control system and bus voltage compensation method of the photovoltaic-diesel DC microgrid without energy storage based on virtual power in the embodiment of the present invention are shown in the figure. The total power of the photovoltaic system is 6kW, the total power of the diesel system is 10kW, and the photovoltaic converter and the diesel converter work in the droop system based on virtual power. Figure 4 As shown in (a), the system load power is 8kW before 0.8s, and the load is 8kW at 0.8s. It can be seen that after the virtual power droop system is adopted, the photovoltaic output is basically stable at close to the limit power, ensuring the maximum utilization of the photovoltaic system under different load conditions; when the system does not adopt the bus voltage compensation method, such as Figure 4 As shown in (b), the bus voltage drops by 16V when the load is put into operation at 0.8s. After the bus voltage compensation method is added, the bus voltage drop is reduced to 9V. It can be seen that after adopting the bus voltage compensation method, the system bus voltage is better supported and the system stability is greatly improved.

[0041] Example 2

[0042] Embodiment 2 of the present invention provides a terminal device corresponding to the above-mentioned embodiment 1. The terminal device may be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of the above-mentioned embodiment.

[0043] The terminal device of this embodiment includes a memory, a processor, and a computer program stored in the memory; the processor executes the computer program in the memory to implement the steps of the method in the above-mentioned embodiment 1.

[0044] In some implementations, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0045] In some other implementations, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited herein.

[0046] Example 3

[0047] Embodiment 3 of the present invention provides a computer-readable storage medium corresponding to the above embodiment 1, on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps of the method of the above embodiment 1 are implemented.

[0048] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0049] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0050] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0051] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0052] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0053] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for supporting bus voltage of a non-storage solar-diesel DC microgrid, wherein the non-storage solar-diesel DC microgrid comprises a photovoltaic module and a diesel generator module, wherein both the photovoltaic module and the diesel generator module are connected to a DC bus; characterized in that: The following steps are involved: S1, the sampled bus voltage signal u bus The high-frequency component u of the bus voltage is obtained by high-pass filter H(s) m ; The bus voltage signal u bus The sampled photovoltaic module output current i o_pv , Diesel generator module output current i o_dg Multiply them together to get the photovoltaic module output power p o_pv The output power of the diesel generator module o_dg ; S2. For photovoltaic modules, when u m <x1&&Δu pv <0, in the first stage of loading, compensation coefficient m pv =n pv1 (P pv -p o_pv ), where P pv is the rated capacity of the photovoltaic module, n pv1 is the coefficient constant of the first stage of input load; when u m >0&&Δu pv <0, in the second stage of loading, compensation coefficient m pv =n pv2 (P pv -p o_pv ), where n pv2 is the second stage coefficient constant of the input load; when u m >x2&&Δu pv >0, in the first stage of load shedding, compensation coefficient m pv =n pv3 p o_pv , where n pv3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu pv >0, in the second stage of load shedding, compensation coefficient m pv =n pv4 p o_pv , where n pv4 is the coefficient constant of the second stage of load shedding; x1 and x2 are the lower and upper limits of the high-frequency component of the bus voltage in steady state respectively; Δu pv is the bus voltage control reference value U of the photovoltaic module ref_pv The actual value of busbar u bus For the diesel generator module, when u m <x1&&Δu dg <0, in the first stage of loading, compensation coefficient m dg =n dg1 (P dg -p o_dg ), where P dg is the rated capacity of the diesel generator module, n dg1 is the coefficient constant of the first stage of input load; when u m >0&&Δu dg <0, in the second stage of loading, compensation coefficient m dg =n dg2 (P dg -p o_dg ), where n dg2 is the second stage coefficient constant of the input load, when u m >x2&&Δu dg >0, in the first stage of load shedding, compensation coefficient m dg =n dg3 p o_dg , where n dg3 is the coefficient constant of the first stage of load shedding, when u m <0&&Δu dg >0, in the second stage of load shedding, compensation coefficient m dg =n dg4 p o_dg , where n pv4 Δu is the coefficient constant of the second stage of load shedding; dg The bus voltage control reference value U of the diesel generator module ref_dg The actual value of busbar u bus difference; S3, the high frequency component of bus voltage u m Multiply by the photovoltaic module compensation coefficient m pv Compensation coefficient m dg , respectively obtain the bus voltage compensation component u of the photovoltaic module cpv The bus voltage compensation component u of the diesel generator module cdg , which are superimposed on the voltage outer loop of the photovoltaic module and diesel generator module control system for compensation.

2. The bus voltage support method of the non-storage solar-diesel DC microgrid according to claim 1 is characterized in that: Also includes: Calculate the reference value U of the PV module bus voltage pv The U of the diesel generator module bus voltage dg ; The reference value U of the photovoltaic module bus voltage pv The bus voltage compensation component u of the photovoltaic module cpv Add them together to get the given value U of the PV module voltage outer loop ref_pv ; The reference value U of the diesel generator module bus voltage dg The bus voltage compensation component u of the diesel generator module cdg Add them together to get the given value U of the diesel generator module voltage outer loop ref_dg ; The photovoltaic module voltage outer loop given value U ref_pv With bus voltage signal u bus Make a difference and get the photovoltaic module voltage deviation signal Δu pv ; Set the diesel generator module voltage outer loop given value U ref_dg With bus voltage signal u bus Make a difference and get the voltage deviation signal Δu of the diesel generator module dg ; The photovoltaic module voltage deviation signal Δu pv Through the voltage outer loop PI controller G cv_pv , get the photovoltaic module current inner loop given value I ref_pv ; The diesel generator module voltage deviation signal Δu dg Through the voltage outer loop PI controller G cv_dg , to the diesel generator module current inner loop given value I ref_dg ; The photovoltaic module current inner loop given value I ref_pv The photovoltaic module output current i o_pv Make a difference and get the photovoltaic module current deviation signal Δi pv ; Set the diesel generator module current inner loop given value I ref_dg The input current i in_dg Make a difference and get the current deviation signal Δi of the diesel generator module dg ; The photovoltaic module current deviation signal Δi pv , Diesel generator module current deviation signal Δi dg Through the current inner loop PI controller G ci_pv , G ci_dg , corresponding to the PWM modulation signal of the photovoltaic module and the PWM modulation signal of the diesel generator module.

3. The busbar voltage support method of the non-storage solar-diesel DC microgrid according to claim 2 is characterized in that: V o It is the output voltage of the photovoltaic-diesel DC microgrid without energy storage when both the photovoltaic module and the diesel generator module are running at no load.

4. The bus voltage support method of the non-storage solar-diesel DC microgrid according to claim 1 is characterized in that: The output ratio of the photovoltaic module and the diesel generator module is k dg :k * pv ;in, where k pv is the photovoltaic droop curve, power coefficient a>>1, P pv is the rated capacity of the photovoltaic module, P dg is the rated capacity of the diesel generator module, V0 and V1 are the rated value and lower limit of the bus voltage respectively, k dg =(V0-V1) / -P dg .

5. A terminal device, characterized in that: include: one or more processors; A memory having one or more programs stored thereon, which, when the one or more programs are executed by the one or more processors, enables the one or more processors to implement the steps of the method according to any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that: The computer program is stored therein, and when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

Images