CN-114865721-B - Combined power generation system and power distribution method thereof

CN114865721BCN 114865721 BCN114865721 BCN 114865721BCN-114865721-B

Abstract

The invention provides a combined power generation system and a power distribution method thereof, wherein the method comprises the steps of collecting a voltage feedback signal of a load power supply bus, and obtaining current power availability values of a first power supply device and a second power supply device; the method comprises the steps of generating a total power demand pre-instruction and a total power demand instruction, taking a low-frequency power instruction as a first power supply device power demand pre-instruction, calculating a second power supply device power demand pre-instruction, outputting the first power supply device power demand instruction and the second power supply device power demand instruction according to a current available power value of the second power supply device, outputting the first power supply device power demand instruction to the first power supply device, outputting the second power supply device power demand instruction to the second power supply device, and repeating the steps until a load stops using electricity. The power distribution system and the method can correspond to transient loads of the loads, absorb feedback charges of the loads and ensure stability of the power generation system and normal operation of each load.

Inventors

LI YONG
XU HUIHUI
XIANG LI
LIU CHANGJIN
QU BO
SHI JINGKUI

Assignees

致瞻科技(上海)有限公司
致瞻科技(上海)有限公司

Dates

Publication Date: 20260421
Application Date: 20220225
Priority Date: 20220225

Claims (7)

1. A method of power distribution for a combined power generation system, comprising the steps of: S1, collecting a voltage feedback signal of a load power supply bus, and acquiring a current power available value of a first power supply device and a current power available value of a second power supply device; s2, comparing the voltage feedback signal with a preset voltage command value to generate a total power demand pre-command; s3, generating a total power demand command based on the total power demand pre-command, the current power available value of the first power supply device and the current power available value of the second power supply device; S4, separating a low-frequency power instruction in the total power demand instruction as a first power supply device power demand pre-instruction, and calculating a difference value between the total power demand instruction and the low-frequency power instruction as a second power supply device power demand pre-instruction; s5, generating a first power supply device power demand instruction and a second power supply device power demand instruction based on the current available power value of the second power supply device; S6, outputting a power demand instruction of the first power supply device to the first power supply device, and outputting a power demand instruction of the second power supply device to the second power supply device; S7, repeating the steps S1 to S6 until the load stops consuming electricity; In the step S3, the total power demand instruction generating method comprises the steps of comparing a total power demand pre-instruction with a current total power available value, and forming and outputting an alarm signal if the total power demand pre-instruction is greater than or equal to the current total power available value, wherein the total power demand pre-instruction is the total power demand instruction if the current total power available value is greater than or equal to the total power demand pre-instruction which is greater than or equal to 0; In step S5, the method for generating the power demand command of the first power supply device and the power demand command of the second power supply device includes: s501, comparing the second power supply device power demand pre-instruction with the current available power value of the second power supply device, and executing step S502 when the second power supply device power demand pre-instruction is less than or equal to the second current available power value of the second power supply device, and executing step S503 when the second power supply device power demand pre-instruction is greater than the second current available power value of the second power supply device; s502, a first power supply device power demand pre-instruction is a first power supply device power demand instruction, and a second power supply device power demand pre-instruction is a second power supply device power demand instruction; s503, the current available power value of the second power supply device is a second power supply device power demand instruction, the difference value between the second power supply device power demand pre-instruction and the current available power value of the second power supply device is used as a power overflow compensation value, and the sum of the power overflow compensation value and the first power supply device power demand pre-instruction is used as a first power supply device power demand instruction; the first power supply device is a micro-combustion engine, and the second power supply device is a storage battery.
2. The power distribution method according to claim 1, wherein in step S1, a sum of a current power availability value of the first power supply device and a current power availability value of the second power supply device is equal to or less than a sum of a maximum power of the first power supply device and a maximum power of the second power supply device.
3. The power distribution method according to claim 2, wherein in step S1, the method for obtaining the current power availability value of the second power supply device is that, based on the state of charge of the second power supply device, when the current charge value of the second power supply device is smaller than a lower threshold value, the current power availability value of the second power supply device is zero, and when the upper threshold value is greater than or equal to the current charge value of the second power supply device and greater than or equal to a lower threshold value, the current power availability value of the second power supply device is a maximum power value allowed by the second power supply device.
4. A power distribution method according to claim 3, wherein the second power supply device charging signal is also formed and output when the second power supply device current charge value is less than the lower threshold value.
5. The combined power generation system is used for realizing the power distribution method of any one of claims 1-4, and is characterized by comprising a power distribution system, wherein the input end of the power distribution system is electrically connected with electric equipment, and the output end of the power distribution system is respectively connected with a first power supply subsystem and a second power supply subsystem; The power demand acquisition module is used for acquiring a voltage feedback signal of the power utilization load bus in real time and generating a total power demand pre-instruction; The total power limiting and alarming module is used for judging the total power demand pre-instruction and generating a total power demand instruction; the power distribution module is used for separating a low-frequency power instruction from the total power demand instruction and forming a first power supply device power demand pre-instruction, and is also used for calculating the difference between the total power demand instruction and the low-frequency power instruction as a second power supply device power demand pre-instruction; The second power supply device power limiting module forms a current power available value of the second power supply device according to the state of charge of the second power supply device, controls the state of the second power supply device and outputs a power demand instruction of the second power supply device.
6. The combined power generation system according to claim 5, wherein the power distribution module comprises a slope controller, an input end of the slope controller is electrically connected with the total power limiting and alarming module, an output end of the slope controller is electrically connected with a low-pass filter, and an output end of the low-pass filter is electrically connected with the first power supply device.
7. The power generation system of claim 5, wherein the power distribution system further comprises a power overflow compensation module for calculating a difference between the second power supply device power demand pre-command and the second power supply device current power availability value as a power overflow compensation value when the second power supply device power demand pre-command > the second power supply device current power availability value, outputting the power overflow compensation value and overlapping the power overflow compensation value with the first power supply device power demand pre-command to serve as the first power supply device power demand command.

Description

Combined power generation system and power distribution method thereof Technical Field The invention relates to the technical field of distributed power generation, in particular to a combined power generation system and a power distribution method thereof. Background The power generation device can provide electric energy for the load so as to ensure the normal operation of the load, for example, the fuel engine is used as a small-sized high-efficiency power generation device to provide electric energy for the load, and the power generation device has the advantages of various fuel forms, high power density, low discharge and the like, and has unique advantages in a distributed power generation system and a distributed power system. However, the power generation system of the gas turbine is a process of converting chemical energy into electric energy through combustion, the power change is slow, the transient load of the load cannot be responded, the problems of influencing the normal operation of the load and the service life of the micro gas turbine are easy to occur, meanwhile, the power of the gas turbine flows unidirectionally, the energy fed back by the load cannot be absorbed, and the problem of energy waste is caused. At present, a super capacitor and chemical energy storage are combined to form a composite power generation system, the composite power generation system is mainly applied to new energy power generation such as photovoltaic power generation and wind power generation, the problems of power supply quality and stability of intermittent energy power generation during sudden change of load are solved, electric energy distribution is realized through an energy management and distribution strategy, for example, in energy management research of a small wind power generation system based on hybrid energy storage, an energy distribution strategy combining a low-pass filter and a fuzzy controller is adopted, a complicated fuzzy control rule is required to be designed, the problem of high implementation difficulty exists, for example, in a control strategy of a storage battery and super capacitor hybrid energy storage system, 4 controllers are designed, 2 controllers are used for stabilizing load fluctuation, and in addition, charging control is carried out according to the charge states of the battery and the capacitor, switching logic among different controllers is required to be designed, and the problems of system fluctuation and instability are easy to occur in the process of frequent switching of the controllers. Disclosure of Invention In order to solve the problems of slow transient power response, incapability of recovering regenerated electric power and the like when fuel is adopted to provide electric energy, the invention provides a combined power generation system and a power distribution method thereof, and according to the advantages of the following different power supply devices, and the load and the transient load can be reasonably and quickly distributed according to the actual power consumption requirement of the load, and the problems of complex design, high implementation difficulty, poor system stability and the like of the combined power generation system in the energy distribution process can be avoided. The technical scheme for realizing the aim of the invention is as follows: In a first aspect, the present invention provides a power distribution method of a combined power generation system, including the steps of: S1, collecting a voltage feedback signal of a load power supply bus, and acquiring a current power available value of a first power supply device and a current power available value of a second power supply device; s2, comparing the voltage feedback signal with a preset voltage command value to generate a total power demand pre-command; s3, generating a total power demand command based on the total power demand pre-command, the current power available value of the first power supply device and the current power available value of the second power supply device; S4, separating a low-frequency power instruction in the total power demand instruction as a first power supply device power demand pre-instruction, and calculating a difference value between the total power demand instruction and the low-frequency power instruction as a second power supply device power demand pre-instruction; s5, generating a first power supply device power demand instruction and a second power supply device power demand instruction based on the current available power value of the second power supply device; S6, outputting a power demand instruction of the first power supply device to the first power supply device, and outputting a power demand instruction of the second power supply device to the second power supply device; and S7, repeating the steps S1 to S6 until the load stops consuming electricity. According to the power distribution method of the combined power generation system