Power conversion energy-saving dispatching device and dispatching control method for coupling biogas power generation with photovoltaic power generation

Abstract

The invention discloses an electric power conversion energy-saving dispatching device and dispatching control method for coupling biogas power generation with photovoltaic power generation, the dispatching device comprises a photovoltaic module, biogas power generation equipment, a multi-port DC-DC converter and a micro-processing controller, a first input port Vin1 of the multi-port DC-DC converter is connected with the photovoltaic module, a second input port Vin2 of the multi-port DC-DC converter is connected with the micro-processing controller, and a third input port Vin3 of the multi-port DC-DC converter is connected with the micro-processing controller. The first input port Vin1 is connected with the biogas power generation equipment, the second input port Vin2 is connected with the biogas power generation equipment, the third input port Vin3 is connected with an external power grid, the first output port Vout is connected with an inverter or a direct-current bus, and the second output port VBpattern is connected with a storage battery; the micro-processing controller is used for outputting PWM waves to control the on and off states of electronic elements in the multi-port DC-DC converter, multi-energy cooperative energy supply is achieved, the disadvantages that a traditional multi-energy complementary system is large in control difficulty, large in device usage amount and insufficient in boost gain are overcome, and compared with a traditional multi-energy cooperative energy supply system, the multi-energy cooperative energy supply system is more integrated and more stable in performance. The system has the advantages of flexibility, less component usage amount, higher efficiency and simpler control.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a power conversion energy-saving dispatching device and dispatching control method for biogas power generation coupled with photovoltaic power generation. Background Technology

[0002] Photovoltaic agriculture, as a modern agricultural development model that combines economic and environmental benefits, is constantly expanding its innovative paths. When deeply integrated with biogas power generation technology, this model not only achieves a qualitative leap in energy supply stability, economic benefits, and environmental benefits, but also creates a new landscape of synergistic development between clean energy power supply and efficient agricultural production. By constructing an agricultural production system that couples biogas power generation and photovoltaic power generation, solar power generation is organically integrated with modern agricultural practices, and organic waste generated during agricultural production is creatively converted into biogas energy to provide auxiliary power support for agricultural production, thereby constructing a closed-loop resource cycle throughout the entire agricultural production process. This model not only outputs clean electricity but also significantly improves the comprehensive utilization efficiency of land.

[0003] However, traditional biogas and photovoltaic (PV) power generation coupled with agricultural energy supply systems require a large number of converters connected in parallel and cascaded to simultaneously input power from multiple sources such as biogas and PV power and achieve the required voltage levels. The extensive use of converters and components increases system losses. Therefore, optimizing the number of components, reducing energy losses, improving voltage boosting capabilities, and addressing multi-source input and power distribution are issues that need to be addressed in the application of converters for biogas and PV power generation coupled with agricultural energy supply. Summary of the Invention

[0004] In view of the above-mentioned prior art, the present invention provides a power conversion energy-saving dispatching device and dispatching control method for biogas power generation coupled with photovoltaic power generation, which mainly solves the technical problems existing in the above-mentioned background art.

[0005] To achieve the above objectives, the technical solution of this invention is implemented as follows: The first aspect of this invention discloses a power conversion energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation. The dispatching device includes: photovoltaic modules, biogas power generation equipment, a multi-port DC-DC converter, and a microprocessor controller, wherein... The first input port V of the multi-port DC-DC converter in1 Connected to photovoltaic modules; second input port V in2 Connect the biogas power generation equipment, third input port V in3 Connect to external power grid, first output port V out Connect to the inverter or DC bus, second output port V Battery Connect the battery; The microprocessor controller is used to output PWM waves to control the on and off states of electronic components in the multi-port DC-DC converter.

[0006] Optionally, the multi-port DC-DC converter includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a first diode D1, a second diode D2, a third diode D3, a first power switch S1, a second power switch S2, a third power switch S3, a fourth power switch S4, a fifth power switch S5, and a first output port V. out Second output port V Bttery and relay K; The first input port V in1 The first inductor L1 is connected to the positive terminal, and the negative terminal of the first inductor L1 is connected to the cathode of the third diode D3. The anode of the third diode D3 is connected to the negative terminal of the fourth inductor L4, the positive terminal of the fourth inductor L4 is connected to the positive terminal of the third capacitor C3, the negative terminal of the third capacitor C3 is connected to the anode of the first diode D1, the anode of the first diode D1 is connected to the emitter of the first power switch S1, and the collector of the first power switch S1 is connected to the negative terminal of the first inductor L1. Third input port V in3 The positive terminal of the second capacitor C2 is connected to the negative terminal of the first inductor L1, the negative terminal of the second capacitor C3 is connected to the negative terminal of the third capacitor C3, the emitter of the fifth power switch S5 is connected to the negative terminal of the third capacitor C3, and the collector of the fifth power switch S5 is connected to the negative terminal of the fourth inductor L4. Second input port V in2 The positive terminal of the first inductor is connected to the positive terminal of the second inductor L2, and the second input port V... in2 The negative terminal of the first inductor L2 is connected to the cathode of the second diode D1; the negative terminal of the second inductor L2 is connected to the anode of the second diode D2; the cathode of the second diode D2 is connected to the positive terminal of the fourth capacitor C4; and the negative terminal of the fourth capacitor C4 is connected to the anode of the first diode D1. The collector of the second power switch S2 is connected to the negative terminal of the second inductor L2; the emitter of the second power switch S2 is connected to the anode of the first diode D1; and the first capacitor C1 is connected to the second input port V. in2 Parallel connection, first output port V out It is connected in parallel with the fourth capacitor C4; the collector of the third power switch S3 is connected to the positive terminal of the fourth capacitor C4, the emitter of the third power switch S3 is connected to the negative terminal of the third inductor L3, and the positive terminal of the third inductor L3 is connected to the second output port V. Battery The positive terminal is connected, and the second output port VBattery The negative terminal of the transistor S4 is connected to the negative terminal of the fourth capacitor; the collector of the fourth power switch S4 is connected to the negative terminal of the third inductor L3; and the emitter of the fourth power switch S4 is connected to the negative terminal of the fourth capacitor C4. The relay K is connected to the second input port V. in2 in parallel.

[0007] Optionally, the scheduling device further includes a voltage and current transmitter connected to the microprocessor controller, the voltage and current transmitter being used to acquire data from the first input port V. in1 Second input port V in2 Third input port V in3 First output port V out Second output port V Battery The voltage and current values.

[0008] A second aspect of this invention discloses a power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation, wherein the control method is applied in any of the aforementioned devices, and the control method includes: When the photovoltaic module supplies power alone, the stable output of electrical energy from the photovoltaic module is achieved by controlling the PWM duty cycle of the first power switch S1 and the second power switch S2. When the biogas power generation equipment supplies power alone, the PWM duty cycle of the second power switch S2 and the on / off state of the relay K are controlled to achieve a stable output of electrical energy from the biogas power generation equipment. When the external power grid supplies power alone, control the PWM duty cycle of the fifth power switch S5; When photovoltaic modules, biogas power generation equipment, and external power grid work together to supply energy, the PWM duty cycle of the first power switch S1, the second power switch S2, and the fifth power switch S5 are controlled synchronously.

[0009] Optionally, the control method further includes: when the first output port V out When the voltage is higher than the set value, the third power switch S3 is turned on, allowing the battery to charge and absorb excess current; when the voltage at the first output port V... out When the voltage is lower than the set value, the third power switch S4 is turned on, causing the battery to discharge and replenish the current.

[0010] Optionally, when the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1 and the second power switch S2 are closed, the relay K and the fifth power switch S5 are turned off, and the photovoltaic module is powered through the first input port V. in The first inductor L1 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, the relay K is closed, and the photovoltaic module is powered through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

[0011] Optionally, when the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the second power switch S2 closes, and the first power switch S1, the fifth power switch S5, and the relay K turn off. The biogas power generation equipment then outputs power through the second input port V. in2 The second inductor L2 is charged, and the fourth capacitor C4 supplies power to the first output port V. out Energy supply; When the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the biogas power generation equipment outputs power through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

[0012] Optionally, when the external power grid supplies power independently and the PWM wave output by the microprocessor controller is at a high potential, the fifth power switch S5, the first power switch S1, the second power switch S2, and the relay K are closed, and the external power grid is connected through the third input port V. in3 The fourth inductor L4 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 has its first output port V. out Energy supply; When the external power grid supplies power alone, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the relay K is closed. The external power grid supplies power through the third input port V. in3 The series inductor L4 charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

[0013] Optionally, when the photovoltaic module, biogas power generation equipment, and external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1, the fifth power switch S5, and the second power switch S2 close, and the relay K turns off. The photovoltaic module connects to the first input port V. in1The inductor L1 is charged, and the biogas generator outputs power through the second input port V. in2 The second capacitor C2, connected in series, charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic modules, biogas power generation equipment, and external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, the fifth power switch S5, and the relay K are turned off. The photovoltaic modules connect through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2. The external power grid is connected through the third input port V. in3 The second capacitor is charged by connecting the fourth inductor L4 in series. The biogas generator charges through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

[0014] The beneficial effects of this invention are as follows: The multi-port DC-DC converter proposed in this application combines photovoltaic module power generation, biogas power generation, battery storage, and external power grid. Three input ports are respectively connected to the photovoltaic module, biogas power generation equipment, and external power grid. One bidirectional output port is connected to the battery, and one unidirectional output port is connected to the DC bus or inverter to supply power to the load. The converter uses maximum power point control combined with PI control to improve energy utilization, solving the problem of high complexity in multi-source input coupling power supply and reducing the problem of large energy losses. Compared with traditional DC-DC converters, this invention has three input ports, one bidirectional output port, and one unidirectional output port. It reduces the power losses caused by cascaded and parallel converters and reduces the number of components used. It has a very wide voltage output range, strong environmental adaptability, high power supply stability, and can meet the coupling input of multiple energy sources. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the application system of the present invention, in which multiple ports realize energy scheduling between biogas power generation, photovoltaic power generation, storage battery, external power grid and output; Figure 2 This is a schematic diagram of the port input DC-DC converter circuit topology of the present invention; Figure 3 This is a schematic diagram of the system of the present invention; Figure 4 A schematic diagram showing that photovoltaic modules and biogas power generation supply energy to the load, with batteries providing auxiliary power, and the PWM wave is at a high potential. Figure 5 A schematic diagram showing that photovoltaic modules and biogas power generation supply energy to the load, with batteries providing auxiliary power, and the PWM wave is at a low potential. Figure 6A schematic diagram showing that photovoltaic modules and biogas power generation supply energy to the load, and battery storage provides energy, with the PWM wave at a high potential. Figure 7 A schematic diagram showing that photovoltaic modules and biogas power generation supply energy to the load, and battery storage provides energy, with the PWM wave at a high potential. Figure 8 A schematic diagram showing that biogas power generation supplies energy to the load, with battery as an auxiliary power source, and the PWM wave is at a high potential. Figure 9 A schematic diagram showing that biogas power generation supplies energy to the load, with battery as an auxiliary power source, and the PWM wave is at a low potential. Figure 10 A schematic diagram showing that the photovoltaic modules supply power to the load, the battery provides auxiliary power, and the PWM wave is at a high potential. Figure 11 A schematic diagram showing that the photovoltaic modules supply power to the load, the battery provides auxiliary power, and the PWM wave is at a low potential. Figure 12 A schematic diagram showing the external power grid supplying power to the load, the battery storing energy, and the PWM wave being at a high potential. Figure 13 A schematic diagram showing the external power grid supplying power to the load, the battery storing energy, and the PWM wave being at a low potential. Figure 14 This is the control block diagram for power switch S1; Figure 15 This is a block diagram of the power balance control at the battery port, which mainly controls the third power switch S3 and the fourth power switch S4. Figure 16 This is a schematic diagram of dual closed-loop voltage and current PI control, which mainly controls the second power switch S2; where Kp is 0.6 and Ki is 5, the output voltage can be stable with small fluctuations. Figure 17 The control block diagram for supplying power to the external power grid mainly controls the fifth power switch S5. Figure 18 The efficiency curves are for output power ranging from 1000W to 17000W. Figure 19 The efficiency curves are for output power ranging from 30,000W to 300,000W. Detailed Implementation

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. In the following description, the expression "some embodiments" refers to a subset of all possible embodiments; however, it should be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0017] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0018] It should be understood that the present invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Furthermore, the terminology used herein is intended only to describe particular embodiments and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0019] It should also be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0021] Please refer to the attached document. Figures 1 to 19 The first aspect of this invention discloses a power conversion energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation. The dispatching device includes: photovoltaic modules, biogas power generation equipment, a multi-port DC-DC converter, and a microprocessor controller. The first input port V of the multi-port DC-DC converter in1 Connected to photovoltaic modules; second input port V in2 Connect the biogas power generation equipment, third input port V in3 Connect to external power grid, first output port V out Connect to the inverter or DC bus, second output port V Battery Connect the battery; The microprocessor controller is used to output PWM waves to control the on and off states of electronic components in the multi-port DC-DC converter.

[0022] Specifically, the energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation disclosed in this application integrates the energy inputs of photovoltaic modules, biogas power generation equipment, and the external power grid through a multi-port DC-DC converter, achieving multi-source coordinated power supply and stable output under the control of a microprocessor controller. The microprocessor controller outputs a PWM wave, controlling the on / off states of electronic components such as power switches in the multi-port DC-DC converter to achieve individual or coordinated power supply to the photovoltaic modules, biogas power generation equipment, and the external power grid; simultaneously, it utilizes the second output port V... Battery The connected battery, through complementary control of corresponding switching transistors, outputs power at the first output port V. out When the voltage is higher than the set value, it shunts and stores energy; when it is lower than the set value, it compensates for the discharge to stabilize the output voltage. It realizes dynamic coordinated scheduling of multiple energy sources, solving the problems of high control difficulty, large number of components, and insufficient boost gain in traditional multi-energy complementary systems. Through integrated design, it reduces the number of components, improves energy utilization efficiency and power supply stability, and is suitable for smart agriculture, agricultural-solar complementary systems, etc. It takes into account both clean energy utilization and power supply reliability, and improves the overall system's economic and environmental benefits.

[0023] Furthermore, the scheduling device also includes a voltage and current transmitter, which is connected to the microprocessor controller and is used to acquire data from the first input port V. in1 Second input port V in2 Third input port V in3 First output port V out Second output port V Battery The voltage and current values.

[0024] Furthermore, the scheduling device also includes an auxiliary power supply, which is connected to the first output port V. out Connected to ensure the stability of the control system operation, the auxiliary power supply adopts a 24V output power module, which converts the voltage level of other power supplies to 24V to power low-voltage, low-power control and monitoring equipment such as microprocessor controllers, voltage and current transmitters, and display devices.

[0025] In some optional embodiments, the multi-port DC-DC converter includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a first diode D1, a second diode D2, a third diode D3, a first power switch S1, a second power switch S2, a third power switch S3, a fourth power switch S4, a fifth power switch S5, and a first output port V. out Second output port V Bttery and relay K; This invention specifies that the direction of inductor charging is positive, and the first input port V in1 The first inductor L1 is connected to the positive terminal, and the negative terminal of the first inductor L1 is connected to the cathode of the third diode D3. The anode of the third diode D3 is connected to the negative terminal of the fourth inductor L4, the positive terminal of the fourth inductor L4 is connected to the positive terminal of the third capacitor C3, the negative terminal of the third capacitor C3 is connected to the anode of the first diode D1, the anode of the first diode D1 is connected to the emitter of the first power switch S1, and the collector of the first power switch S1 is connected to the negative terminal of the first inductor L1. Third input port V in3 The positive terminal of the second capacitor C2 is connected to the negative terminal of the first inductor L1, the negative terminal of the second capacitor C3 is connected to the negative terminal of the third capacitor C3, the emitter of the fifth power switch S5 is connected to the negative terminal of the third capacitor C3, and the collector of the fifth power switch S5 is connected to the negative terminal of the fourth inductor L4. Second input port V in2 The positive terminal of the first inductor is connected to the positive terminal of the second inductor L2, and the second input port V... in2 The negative terminal of the first inductor L2 is connected to the cathode of the second diode D1; the negative terminal of the second inductor L2 is connected to the anode of the second diode D2; the cathode of the second diode D2 is connected to the positive terminal of the fourth capacitor C4; and the negative terminal of the fourth capacitor C4 is connected to the anode of the first diode D1. The collector of the second power switch S2 is connected to the negative terminal of the second inductor L2; the emitter of the second power switch S2 is connected to the anode of the first diode D1; and the first capacitor C1 is connected to the second input port V. in2 Parallel connection, first output port V outIt is connected in parallel with the fourth capacitor C4; the collector of the third power switch S3 is connected to the positive terminal of the fourth capacitor C4, the emitter of the third power switch S3 is connected to the negative terminal of the third inductor L3, and the positive terminal of the third inductor L3 is connected to the second output port V. Battery The positive terminal is connected, and the second output port V Battery The negative terminal of the transistor S4 is connected to the negative terminal of the fourth capacitor; the collector of the fourth power switch S4 is connected to the negative terminal of the third inductor L3; and the emitter of the fourth power switch S4 is connected to the negative terminal of the fourth capacitor C4. The relay K is connected to the second input port V. in2 in parallel.

[0026] In a multi-port DC-DC converter, the first capacitor C1, the third capacitor C3 and the fourth capacitor C4 play the role of filtering and voltage regulation, while the second capacitor C2 serves as an intermediate capacitor for energy transfer. The microprocessor controller primarily uses PI control, MPPT control, and power balance control algorithms to adjust the PWM duty cycle of each power switch. Voltage and current feedback, as well as PWM wave generation, are all calculated and output by the microprocessor controller. After initialization, the microprocessor controller uses a rising-falling waveform and controls the PWM duty cycle by changing the comparison values ​​of CMP1 and CMP2 at different PWM output ports, thereby altering the input power at each input port of the multi-port DC-DC converter.

[0027] A PI controller is a controller with proportional and integral functions. Its main function is to adjust the control system's operation based on the error between the output value and the reference value, gradually reducing the error until a steady state is reached. It can also provide rapid response and achieve steady-state control. In this system, the PI control is mainly used to control the voltage and current at the output port. The outer loop of the dual-loop control is a voltage detection loop, and the inner loop is a current detection loop. By detecting both current and voltage data, it can achieve steady-state control of both voltage and current.

[0028] The first input port V of this system in1 Connecting to photovoltaic modules, the control primarily employs maximum power point control, while grid-supplied and battery-supplied power utilizes power balance control. The second input port V is connected to the biogas power generation equipment. in2 PI control is used to stabilize the output voltage.

[0029] Since the multi-port DC-DC converter designed in this application needs to carry a large amount of current during operation, the components used in it need to be specially selected. Since the system withstands the largest voltage and current when all sources supply power at the same time, the calculation mode is to use photovoltaic modules, biogas power generation, external power grid and battery power supply at the same time.

[0030] The voltage and current stresses that the first power switch S1, the second power switch S2, the third power switch S3, the fourth power switch S4, and the fifth power switch S5 need to withstand are calculated using the following formulas:

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] Where, d S1 It is the duty cycle of the first power switch S1, d S2 It is the duty cycle of the second power switch S2, d S3 It is the duty cycle of the second power switch S3, d S4 It is the duty cycle of the second power switch S4, V i1 It is the first input port V in1 The input voltage, V i2 It is the second input port V in2 The input voltage, V i3 It is the second input port V in3 The input voltage, R is the first output port V out The load. V S1max I is the maximum voltage stress of the first power switch S1. S1max This represents the maximum current stress of the first power switch S1. V S2max I is the maximum voltage stress of the second power switch S2. S2max This represents the maximum current stress of the second power switch S2. S3max For the maximum voltage stress of the third power switch S3, I S3max This represents the maximum current stress of the third power switch S3. S4max For the maximum voltage stress of the fourth power switch S4, I S4maxThis represents the maximum current stress of the fourth power switch, S4. S5max For the maximum voltage stress of the fifth power switch S5, I S5max This represents the maximum current stress of the fifth power switch S5. o It is the first output port V out The output power required, V o It is the first output port V out The output voltage, Io is the first output port V. out The output current, V B It is the second output port V Battery voltage, I B It is the second output port V Battery The current.

[0041] The selection results of the first power switch S1, the second power switch S2, and the fifth power switch S5 are shown in Table 1 below.

[0042] Table 1 Calculated values ​​for power switching transistors

[0043] The voltage and current stresses that the first diode D1, the second diode D2, and the third diode D3 need to withstand are calculated using the following formulas:

[0044]

[0045]

[0046]

[0047]

[0048]

[0049] Among them, V D1 It is the maximum voltage stress of the first diode D1, I D1 This is the current stress of the first diode, D1. V D2 It is the maximum voltage stress of the second diode D2, I. D2 This is the current stress of the second diode, D2. V D3 It is the maximum voltage stress of the third diode D3, I. D3 This refers to the current stress of the third diode, D3. V i1 It is the first input port V in1 voltage, V i3 It is the third input port V in3 voltage, d S1It is the duty cycle of the first power switch S1, d S5 It is the duty cycle of the fifth power switch S5, and Io is the first output port V. out The current, V o It is the first output port V out The voltage is R, and R is the output resistance value of the first output port.

[0050] The first diode D1, the second diode D2, and the third diode D3 were selected according to the calculation results as shown in Table 2.

[0051] Table 2 Diode Calculation Values

[0052] The voltage stress on the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 is the same as that on the parallel-connected ports or power switching transistors. The minimum capacitance that they need to withstand is calculated using the following formula. In the calculation, the ripple rate is taken as 0.05, and the frequency is taken as 20kHz.

[0053]

[0054]

[0055]

[0056]

[0057] In the formula d S2 It is the duty cycle of the second power switch S2, d S1 It is the duty cycle of the first power switch S1, d S5 It is the duty cycle of the fifth power switch S5, P o It is the first output port V out power, V i1 It is the first input port V in1 voltage, V i2 It is the second input port V in2 voltage, V i3 It is the third input port V in3 voltage, V o It is the first output port V out The voltage is R, where R is the resistance of the load at the first output port. C F is the voltage ripple factor, and f is the switching frequency. C1 It is the capacitance value of the first capacitor C1, F. C2 It is the capacitance value of the second capacitor C2, F. C3 It is the capacitance value of the first capacitor C3, F. C4 It is the capacitance value of the first capacitor C1.

[0058] The calculation results for the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are shown in Table 3.

[0059] Table 3 Calculated Capacitance Values

[0060] The currents of the first inductor L1, the second inductor L2, the third inductor L3, and the fourth inductor L4 are consistent with the current stress of the power switch transistors connected in series. The minimum inductance value that needs to be withstood is calculated using the following formula. The inductance ripple factor is taken as 0.4, the frequency as 20kHz, and the selection based on the calculation results is shown in Table 4.

[0061]

[0062]

[0063]

[0064]

[0065] Among them, H L1 H is the inductance value of the first inductor L1. L2 This is the inductance value of the second inductor L2, H. L3 H is the inductance value of the third inductor L3. L4 This is the inductance value of the fourth inductor, L4. V i1 It is the first input port V in1 voltage, V i2 It is the second input port V in2 voltage, V i3 It is the third input port V in3 voltage, V B It is the second output port V Battery voltage, V o It is the first output port V out The voltage. d S1 It is the duty cycle of the first power switch S1, d S2 It is the duty cycle of the second power switch S2, d S3 It is the duty cycle of the second power switch S3, d S5 It is the duty cycle of the second power switch S5. L It is the inductor current ripple factor, T S It is the period of the PWM wave.

[0066] The calculation results for the first inductor L1, the second inductor L2, the third inductor L3, and the fourth inductor L4 are shown in Table 4.

[0067] Table 4 Calculated Inductance Values

[0068] Based on the minimum value calculated above, and considering safety margin, long-term reliability, and future scalability, the specific value should be at least 1.3 times larger than the calculated value when selecting a model. The specific selection is shown in Table 5.

[0069] Table 5 Component Selection

[0070] After selecting the components, the converter was tested. The input voltage of the photovoltaic module was 160V, the input voltage of the biogas generator was 200V, the input voltage of the battery was 200V, and the input voltage of the external power grid was 200V. During testing, different inputs were tested separately. The efficiency and voltage gain when the biogas generator was the sole power source are shown in Table 6; the converter efficiency when the photovoltaic module was the sole power source is shown in Table 7; the converter efficiency and voltage gain when the external power source was the sole power source for the load are shown in Table 8; the converter efficiency and voltage gain when the battery was the sole power source for the load are shown in Table 9; and the converter efficiency and voltage gain when the battery was storing energy are shown in Table 10.

[0071] Table 6. Converter efficiency and voltage gain when biogas is the sole power source.

[0072] Table 7 Converter efficiency and voltage gain when photovoltaic modules are powered alone.

[0073] Table 8 Efficiency and Voltage Gain When Powered Independently by an External Power Grid

[0074] Table 9. Converter efficiency and voltage gain when powered solely by battery

[0075] Table 10 Efficiency and Voltage Gain of Battery Energy Storage

[0076] When the input power supply is stable and there is no power limit, the first output port V can be changed by altering the running time or duty cycle of the two phases within a PWM wave cycle. out Second output port V Battery The voltage between the input and output ports of the converter can be derived by using the inductor volt-second balance equation and the capacitor ampere-second balance equation and by establishing a small-signal model, as shown in the following equation.

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086] In the formula, M1 represents the first input port V. in1 For the first output port V out The gain, M2 represents the gain of the second input port V. in2 For the first output port V out The gain, M3 represents the third input port V in3 For the first output port V out The gain, M4 represents the first output port V out For the second output port V Battery The gain, M5 represents the gain of the second output port V. Battery For the first output port V out The gain, M6 represents the first input port V in1 Second input port V in2 For the first output port V out The gain, M7 represents the third input port V in3 Second input port V in2 For the first output port V out The gain, M8 represents the first input port V in1 and the third input port V in3 For the first output port V out The gain, M9 represents the first input port V in1 Second input port V in2 and the third input port V in3 For the first output port V out The gain. V i1 It is the first input port V in1 The input voltage, V i2 It is the second input port V in2 The input voltage, V i3 It is the second input port Vin3 The input voltage, V o It is the first output port V out voltage, V B It is the second output port V Battery Voltage. d S1 It is the duty cycle of the first power switch S1, d S2 It is the duty cycle of the second power switch S2, d S3 It is the duty cycle of the second power switch S3, d S4 It is the duty cycle of the second power switch S4, d S5 It is the duty cycle of the second power switch S5.

[0087] When the PWM duty cycle controlling the first power switch S1, the second power switch S2, the third power switch S3, the fourth power switch S4, and the fifth power switch S5 is between 10% and 90%, assuming all input port voltages are consistent, the output voltage of the multi-port DC-DC converter is between 1.12x and 100x boost. The second aspect of this invention discloses a power conversion dispatch control method for a biogas power generation meter combined with photovoltaic power generation, the control method being applied to any of the aforementioned devices, the control method comprising: When the photovoltaic module supplies power alone, the stable output of electrical energy from the photovoltaic module is achieved by controlling the PWM duty cycle of the first power switch S1 and the second power switch S2. When the biogas power generation equipment supplies power alone, the PWM duty cycle of the second power switch S2 and the on / off state of the relay K are controlled to achieve a stable output of electrical energy from the biogas power generation equipment. When the external power grid supplies power alone, control the PWM duty cycle of the fifth power switch S5; When photovoltaic modules, biogas power generation equipment, and external power grid work together to supply energy, the PWM duty cycle of the first power switch S1, the second power switch S2, and the fifth power switch S5 are controlled synchronously.

[0088] When the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1 and the second power switch S2 are closed, the relay K and the fifth power switch S5 are turned off, and the photovoltaic module is powered through the first input port V. in The first inductor L1 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, the relay K is closed, and the photovoltaic module is powered through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

[0089] When the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the second power switch S2 closes, while the first power switch S1, the fifth power switch S5, and the relay K turn off. The biogas power generation equipment then outputs power through the second input port V. in2 The second inductor L2 is charged, and the fourth capacitor C4 supplies power to the first output port V. out Energy supply; When the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the biogas power generation equipment outputs power through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

[0090] When the external power grid supplies power alone, and the PWM wave output by the microprocessor controller is at a high level, the fifth power switch S5, the first power switch S1, the second power switch S2, and the relay K are closed, and the external power grid flows through the third input port V. in3 The fourth inductor L4 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 has its first output port V. out Energy supply; When the external power grid supplies power alone, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the relay K is closed. The external power grid supplies power through the third input port V. in3 The series inductor L4 charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

[0091] When photovoltaic modules, biogas power generation equipment, and the external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1, the fifth power switch S5, and the second power switch S2 close, and the relay K turns off. The photovoltaic module connects to the first input port V... in1 The inductor L1 is charged, and the biogas generator outputs power through the second input port V. in2The second capacitor C2, connected in series, charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic modules, biogas power generation equipment, and external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, the fifth power switch S5, and the relay K are turned off. The photovoltaic modules connect through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2. The external power grid is connected through the third input port V. in3 The second capacitor is charged by connecting the fourth inductor L4 in series. The biogas generator charges through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

[0092] In some embodiments, the control method further includes: when the first output port V out When the voltage is higher than the set value, the third power switch S3 is turned on, allowing the battery to charge and absorb excess current; when the voltage at the first output port V... out When the voltage is lower than the set value, the third power switch S4 is turned on, causing the battery to discharge and replenish the current.

[0093] Specifically, when the first output port V out When the voltage is higher than the set value, the battery is used to power the first output port V. out The current is shunted to reduce the voltage at the first output port V. out The output current is adjusted to ensure that the output voltage reaches the set value. During this stage, the third power switch S3 acts as a step-down switch, and the fourth power switch S4 acts as a freewheeling switch for the third inductor. When the first output port V out When the voltage is lower than the set value, the battery is used to power the first output port V. out Supplement current to increase V at the first output port out The output current is adjusted to ensure that the output voltage reaches the set value. During this stage, the fourth power switch S4 acts as a boost switch, and the third power switch S3 acts as an output switch.

[0094] By changing the time ratio of the two stages of each switching transistor within a cycle, the boost output of the converter and the energy distribution between different ports are achieved. Since components have withstand voltage and current values, the voltage stress, current stress, capacitance value of capacitors, and inductance value of each component are calculated based on the input and output voltages and currents of the converter, facilitating the selection and matching of different requirements.

[0095] In summary, the multi-port DC-DC converter designed in this application serves as an energy dispatching and energy-saving device. The first power switch S1, second power switch S2, third power switch S3, fourth power switch S4, and fifth power switch S5 are all controlled using different control strategies. However, to simplify control, all switches can be synchronously controlled during implementation. The photovoltaic module connects to the first input port V... in1 Give the first output port V out When supplying energy, the existing maximum power point control is used, and the biogas power generation equipment is connected through the second input port V. in2 Give the first output port V out PI control is used for power supply, and the external power grid is connected through the third input port V. in3 Give the first output port V out A power balance control strategy is used when supplying power, and the battery is connected to the second output port V. Battery Give the first output port V out Power balance control is used for power supply or voltage regulation. All control voltage and current feedback includes the first input port V. in1 Second input port V in2 Third input port V in3 First output port V out1 Second output port V Battery The voltage and current transmitters collect and transmit data to the microprocessor controller for calculation and control.

[0096] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power conversion and energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation, characterized in that, The scheduling device includes: photovoltaic modules, biogas power generation equipment, a multi-port DC-DC converter, and a microprocessor controller, wherein... The first input port V of the multi-port DC-DC converter in1 Connected to photovoltaic modules; second input port V in2 Connect the biogas power generation equipment, third input port V in3 Connect to external power grid, first output port V out Connect to the inverter or DC bus, second output port V Battery Connect the battery; The microprocessor controller is used to output PWM waves to control the on and off states of electronic components in the multi-port DC-DC converter.

2. The power conversion and energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation according to claim 1, characterized in that, The multi-port DC-DC converter includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a first diode D1, a second diode D2, a third diode D3, a first power switch S1, a second power switch S2, a third power switch S3, a fourth power switch S4, a fifth power switch S5, and a first output port V. out Second output port V Bttery and relay K; The first input port V in1 The first inductor L1 is connected to the positive terminal, and the negative terminal of the first inductor L1 is connected to the cathode of the third diode D3. The anode of the third diode D3 is connected to the negative terminal of the fourth inductor L4, the positive terminal of the fourth inductor L4 is connected to the positive terminal of the third capacitor C3, the negative terminal of the third capacitor C3 is connected to the anode of the first diode D1, the anode of the first diode D1 is connected to the emitter of the first power switch S1, and the collector of the first power switch S1 is connected to the negative terminal of the first inductor L1. Third input port V in3 The positive terminal of the second capacitor C2 is connected to the negative terminal of the first inductor L1, the negative terminal of the second capacitor C3 is connected to the negative terminal of the third capacitor C3, the emitter of the fifth power switch S5 is connected to the negative terminal of the third capacitor C3, and the collector of the fifth power switch S5 is connected to the negative terminal of the fourth inductor L4. Second input port V in2 The positive terminal of the first inductor is connected to the positive terminal of the second inductor L2, and the second input port V... in2 The negative terminal of the first inductor L2 is connected to the cathode of the second diode D1; the negative terminal of the second inductor L2 is connected to the anode of the second diode D2; the cathode of the second diode D2 is connected to the positive terminal of the fourth capacitor C4; and the negative terminal of the fourth capacitor C4 is connected to the anode of the first diode D1. The collector of the second power switch S2 is connected to the negative terminal of the second inductor L2; the emitter of the second power switch S2 is connected to the anode of the first diode D1; and the first capacitor C1 is connected to the second input port V. in2 Parallel connection, first output port V out It is connected in parallel with the fourth capacitor C4; the collector of the third power switch S3 is connected to the positive terminal of the fourth capacitor C4, the emitter of the third power switch S3 is connected to the negative terminal of the third inductor L3, and the positive terminal of the third inductor L3 is connected to the second output port V. Battery The positive terminal is connected, and the second output port V Battery The negative terminal of the transistor S4 is connected to the negative terminal of the fourth capacitor; the collector of the fourth power switch S4 is connected to the negative terminal of the third inductor L3; and the emitter of the fourth power switch S4 is connected to the negative terminal of the fourth capacitor C4. The relay K is connected to the second input port V. in2 in parallel.

3. The power conversion and energy-saving dispatching device for biogas power generation coupled with photovoltaic power generation according to claim 2, characterized in that, The scheduling device further includes a voltage and current transmitter, which is connected to the microprocessor controller. The voltage and current transmitter is used to acquire data from the first input port V. in1 Second input port V in2 Third input port V in3 First output port V out Second output port V Battery The voltage and current values.

4. A power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation, characterized in that, The control method is applied to the apparatus according to any one of claims 1-3, and the control method includes: When the photovoltaic module supplies power alone, the stable output of electrical energy from the photovoltaic module is achieved by controlling the PWM duty cycle of the first power switch S1 and the second power switch S2. When the biogas power generation equipment supplies power alone, the PWM duty cycle of the second power switch S2 and the on / off state of the relay K are controlled to achieve a stable output of electrical energy from the biogas power generation equipment. When the external power grid supplies power alone, control the PWM duty cycle of the fifth power switch S5; When photovoltaic modules, biogas power generation equipment, and external power grid work together to supply energy, the PWM duty cycle of the first power switch S1, the second power switch S2, and the fifth power switch S5 are controlled synchronously.

5. The power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation according to claim 4, characterized in that, The control method further includes: when the first output port V out When the voltage is higher than the set value, the third power switch S3 is turned on, allowing the battery to charge and absorb excess current; when the voltage at the first output port V... out When the voltage is lower than the set value, the third power switch S4 is turned on, causing the battery to discharge and replenish the current.

6. The power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation according to claim 4, characterized in that, When the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1 and the second power switch S2 are closed, the relay K and the fifth power switch S5 are turned off, and the photovoltaic module is powered through the first input port V. in The first inductor L1 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic module is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, the relay K is closed, and the photovoltaic module is powered through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

7. The power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation according to claim 4, characterized in that, When the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a high potential, the second power switch S2 closes, while the first power switch S1, the fifth power switch S5, and the relay K turn off. The biogas power generation equipment then outputs power through the second input port V. in2 The second inductor L2 is charged, and the fourth capacitor C4 supplies power to the first output port V. out Energy supply; When the biogas power generation equipment is powered independently and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the biogas power generation equipment outputs power through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

8. The power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation according to claim 4, characterized in that, When the external power grid supplies power alone, and the PWM wave output by the microprocessor controller is at a high level, the fifth power switch S5, the first power switch S1, the second power switch S2, and the relay K are closed, and the external power grid flows through the third input port V. in3 The fourth inductor L4 is charged, the second capacitor C2 charges the second inductor L2, and the fourth capacitor C4 has its first output port V. out Energy supply; When the external power grid supplies power alone, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, and the fifth power switch S5 are turned off, and the relay K is closed. The external power grid supplies power through the third input port V. in3 The series inductor L4 charges the second capacitor C2, and the second inductor L2 charges the fourth capacitor C4 and the first output port V. out Energy supply.

9. A power conversion dispatch control method for biogas power generation coupled with photovoltaic power generation according to claim 4, characterized in that, When photovoltaic modules, biogas power generation equipment, and the external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a high potential, the first power switch S1, the fifth power switch S5, and the second power switch S2 close, and the relay K turns off. The photovoltaic module connects to the first input port V... in1 The inductor L1 is charged, and the biogas generator outputs power through the second input port V. in2 The second capacitor C2, connected in series, charges the second inductor L2, and the fourth capacitor C4 charges the first output port V. out Energy supply; When the photovoltaic modules, biogas power generation equipment, and external power grid work together to provide energy, and the PWM wave output by the microprocessor controller is at a low potential, the first power switch S1, the second power switch S2, the fifth power switch S5, and the relay K are turned off. The photovoltaic modules connect through the first input port V. in1 The first inductor L1, connected in series, charges the second capacitor C2. The external power grid is connected through the third input port V. in3 The second capacitor is charged by connecting the fourth inductor L4 in series. The biogas generator charges through the second input port V. in2 The second inductor L2 is connected in series with the fourth capacitor C4 and the first output port V. out Energy supply.

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