A power balancing method for multi-machine grid-connected marine diesel generators

Abstract

The present invention discloses a power balancing method for the grid-connected multi-machine marine diesel generator. The method is based on a digital power balancing matrix module connected to the diesel generator set. The digital power balancing matrix module is composed of a grid-connected controller, a switch state diagnostic device, a grid-connected matrix generator and a power given distributor connected in sequence. The method of the present invention can realize the digitalization and intelligence of the grid-connected multi-machine diesel generator. Compared with the traditional distributed solution, the hard-wired connection between the diesel generators can be eliminated. The grid connection no longer relies on the complex diesel generator circuit breaker linkage logic, which reduces the complexity of the diesel power generation grid-connected system and improves the reliability and scalability of the system.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronic equipment and control thereof, and particularly relates to a power balancing method for grid-connected multiple marine diesel generators. Background Art

[0002] New energy ships have garnered widespread attention within the industry, experiencing significant development and widespread adoption in recent years. This has placed higher demands on the stability and economic efficiency of marine power plants. To achieve this, most current marine power plants utilize multiple units in parallel and are developing towards digital and intelligent control.

[0003] Traditional distributed control solutions require hard-wiring of diesel generator circuit breakers for power distribution, and complex logic linkage is required between each diesel generator circuit breaker. This results in a complex system, low reliability, and inconvenient expansion.

[0004] Therefore, adopting digital matrix control is a way to solve the problems of complexity, low reliability and inconvenient expansion of diesel power generation grid-connected systems. Summary of the Invention

[0005] In order to realize digital and intelligent control of diesel generator grid connection, the present invention provides a power balancing method for multiple marine diesel generator grid connection, so as to realize digital and intelligent control of diesel generator grid connection, reduce hardware cost and improve system reliability.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a power balancing method for multiple marine diesel generators connected to the grid, based on a digital power balancing matrix module connected to the diesel generator set, the digital power balancing matrix module being composed of a grid controller, a switch state diagnostic device, a grid matrix generator, and a power setting distributor connected in sequence, including the following steps:

[0007] S1 first receives the current running diesel generator power and switch status through the grid-connected controller and inputs them into the switch status diagnostic device;

[0008] S2, then generates networking matrix elements through the switch status diagnostics device and inputs them into the grid-connected matrix generator;

[0009] S3, the grid-connected matrix generator generates a networking matrix based on the input networking matrix elements and inputs a power given distributor;

[0010] S4, the power reference distributor of the digital power sharing matrix module solves the current system power average value according to the networking matrix and the output elements provided by the grid-connected controller as the power reference value of the grid-connected diesel generator.

[0011] In the power sharing method for connecting multiple marine diesel generators to the grid, in step S2, the switch state diagnostic device uses a grid logic algorithm to generate a diesel generator parallel state based on the diesel generator breaker switch state collected by the grid controller.

[0012] Furthermore, the grid-connected logic algorithm is developed by disassembling a typical power grid relationship diagram and classifying diesel generator circuit breakers. Diesel generator circuit breakers can be divided into branch circuit breakers, main bus tie circuit breakers, and auxiliary bus tie circuit breakers. The grid-connected logic algorithm is formed based on the characteristics of the diesel generator circuit breakers. The algorithm logic is as follows:

[0013] a) Branch circuit breaker makes judgment on and;

[0014] b) Judgment of branch circuit breaker and bus tie circuit breaker;

[0015] c) Make judgment between the main bus tie circuit breaker and the auxiliary bus tie circuit breaker.

[0016] The power sharing method for connecting multiple marine diesel generators to the grid is described. In step S3, the grid connection matrix generator takes the grid connection status of the diesel generator as input and generates a multi-dimensional network matrix by a multi-dimensional matrix operation method: assuming that there are m diesel generators, an M*M dimensional matrix Z is established, Z XY 1 means that the diesel generator numbered X and the diesel generator numbered Y are connected in parallel, then a multi-dimensional network matrix Z is generated = [Z X1 Z x2 … Z XM ], the multi-dimensional networking matrix and the output elements of the grid-connected controller input power given distributor.

[0017] In the power balancing method for connecting multiple marine diesel generators to the grid, in step S4, the power setting distributor uses a power balancing algorithm to solve the power setting of the pre-grid-connected diesel generator: the pre-grid-connected diesel generator power setting = the current total operating power / (the number of currently operating diesel generators + the number of pre-grid-connected diesel generators).

[0018] The beneficial effects of the present invention are as follows: the control method of the present invention is based on the power droop control of the marine diesel generator, and adopts a method combining a digital power balancing matrix module with the power droop control to realize the power balancing of multiple marine diesel generators connected to the grid. The method of the present invention can eliminate the hard-wired connection between the diesel generators, and the grid connection no longer relies on the complex diesel generator circuit breaker linkage logic, thereby reducing the complexity of the diesel power generation grid-connected system, improving the reliability and scalability of the system, and improving the digitization and intelligence of the diesel generator grid-connected system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A power droop control system for a diesel generator of the present invention;

[0020] Figure 2 This is a structural diagram of the digital power sharing matrix module of the present invention.

[0021] The reference numerals of the figures are: 1—diesel generator set, 2—digital power sharing matrix module, 21—grid controller, 22—switch state diagnostic device, 23—grid matrix generator, 24—power setting distributor. DETAILED DESCRIPTION

[0022] The following further describes the implementation of the present invention with reference to specific examples and drawings.

[0023] Reference Figure 1 、 Figure 2 As shown, the present invention discloses a power sharing method for connecting multiple marine diesel generators to the grid. The method is based on a digital power sharing matrix module 2 connected to a diesel generator set 1. The method uses a control method combining the digital power sharing matrix module 2 with power droop control. The digital power sharing matrix module 2 is composed of a grid connection controller 21, a switch state diagnostic device 22, a grid connection matrix generator 23, and a power setting distributor 24. The method specifically includes the following steps.

[0024] S1, first receive the current running diesel generator power and switch status through the grid controller 21, and input them into the switch status diagnostic device 22.

[0025] S2: The switch state diagnostic device 22 then generates a network matrix element and inputs it into the grid matrix generator 23. The network matrix element in this step is implemented using a grid logic algorithm. The switch state diagnostic device 22 uses the grid logic algorithm to generate the diesel generator parallel state based on the diesel generator circuit breaker switch state collected by the grid controller 21.

[0026] The grid-connected logic algorithm is based on the typical power grid relationship diagram and classifies the diesel generator circuit breakers. The diesel generator circuit breakers can be divided into branch circuit breakers, main bus tie circuit breakers, and auxiliary bus tie circuit breakers. The grid-connected logic algorithm is formed based on the characteristics of the diesel generator circuit breakers. The algorithm logic is as follows:

[0027] a) Branch circuit breaker makes judgment on and;

[0028] b) Judgment of branch circuit breaker and bus tie circuit breaker;

[0029] c) Make judgment between the main bus tie circuit breaker and the auxiliary bus tie circuit breaker.

[0030] S3, the grid matrix generator 23 generates a network matrix based on the input network matrix elements and inputs the power given distributor 24. In this step, the grid matrix generator 23 takes the grid connection status of the diesel generator as input and generates a multi-dimensional network matrix through a multi-dimensional matrix operation method. Assuming that there are m diesel generators in the system, an M*M dimensional matrix Z is established, Z xY If it is 1, it means that the diesel generator numbered X and the diesel generator numbered Y are connected in parallel, and a multi-dimensional network matrix is ​​generated:

[0031] Z=[Z X1 Z X2 … Z XM ],

[0032] The output elements of the multi-dimensional networking matrix and the grid-connected controller 21 are fed into the power setting distributor 24 as input.

[0033] In step S4, the power reference allocator 24 of the digital power balancing matrix module 2 calculates the current system power mean based on the networking matrix and the output elements provided by the grid connection controller 21. This is used as the grid-connected diesel generator power reference. In this step, the power reference allocator 24 uses a power balancing algorithm to calculate the pre-grid-connected diesel generator power reference: the core principle of the power balancing algorithm is "pre-grid-connected diesel generator power reference = current operating total power / (number of currently operating diesel generators + number of pre-grid-connected diesel generators)."

[0034] Assuming that each diesel generator is given active power as P and reactive power as Q, the power given matrix is:

[0035] P X =[P1 P2 … P3][Z X1 Z X2 … Z XM ] T / (Z X1 +Z X2 …+Z XM )

[0036] Q X =[Q1 Q2 … Q3][Z X1 Z X2 … Z XM ] T / (Z X1 +Z X2 …+Z XM ).

[0037] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some embodiments of its application. A person skilled in the art may make several modifications and improvements without departing from the inventive concept of the present invention, and all of these modifications and improvements fall within the scope of protection of the present invention.

Claims

1. A power sharing method for connecting multiple marine diesel generators to the grid, based on a digital power sharing matrix module (2) connected to a diesel generator set (1), wherein the digital power sharing matrix module (2) is composed of a grid connection controller (21), a switch state diagnostic device (22), a grid connection matrix generator (23) and a power setting distributor (24) connected in sequence, and characterized in that: Includes the following steps S1, first the grid-connected controller (21) receives the current operating diesel generator power and switch status, and inputs them into the switch status diagnostic device (22); S2, then the switch state diagnostic device (22) generates a network matrix element and inputs it into the grid matrix generator (23), wherein the switch state diagnostic device (22) uses the grid logic algorithm to generate the diesel generator parallel state based on the switch state of the diesel generator circuit breaker collected by the grid controller (21). The grid logic algorithm classifies the diesel generator circuit breaker into branch circuit breakers, main bus tie circuit breakers and auxiliary bus tie circuit breakers by disassembling the typical power grid relationship diagram, and forms a grid logic algorithm based on the characteristics of the diesel generator circuit breaker. The algorithm logic is as follows: a) Branch circuit breaker makes judgment on and; b) Judgment of branch circuit breaker and bus tie circuit breaker; c) Make judgment between the main bus tie circuit breaker and the auxiliary bus tie circuit breaker; S3, the grid-connected matrix generator (23) generates a network matrix according to the network matrix elements and inputs the power given distributor (24), wherein the grid-connected matrix generator (23) takes the grid-connected state of the diesel generator as input, and assumes that there are m diesel generators, and establishes an M*M dimensional matrix, Z XY If it is 1, it means that the diesel generator numbered X and the diesel generator numbered Y are connected in parallel, then a multi-dimensional network matrix is ​​generated. , the output elements of the multi-dimensional networking matrix and the grid-connected controller (21) are input to a power given distributor (24); S4, the power setting distributor (24) calculates the current system power mean value based on the network matrix and the output elements, and uses it as the power setting value of the grid-connected diesel generator.

2. A power sharing method for multi-machine grid-connected marine diesel generators according to claim 1, characterized in that: In step S4, the power setting distributor (24) uses a power sharing algorithm to solve the power setting of the pre-grid-connected diesel generator: The power setting of pre-grid-connected diesel generators = current operating total power / (number of currently operating diesel generators + number of pre-grid-connected diesel generators).

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