Building power distribution system, mains power control method, and mains power controller

Abstract

The present invention discloses a building power distribution system, including a DC bus, an AC / DC converter group, and a mains power controller. The AC / DC converter group is connected to the municipal power grid through an AC branch, the AC / DC converter group is connected to the DC bus through a DC branch, and the AC / DC converter group is connected to the mains power controller for communication via a communication line. The present invention also discloses a mains power control method, including: obtaining a measured voltage value of the DC bus; comparing whether the measured voltage value is between a preset voltage upper limit value and a preset voltage lower limit value; obtaining a mains power target value and a mains power measured value; calculating a power deviation value; calculating a voltage setting value; recording a power deviation value and a voltage setting value; and adjusting the voltage of the DC bus to the voltage setting value. The present invention also discloses a mains power controller, wherein a processor executes the steps in the mains power control method. Compared with the prior art, it does not rely on an additional communication system, and has the advantages of low cost, high reliability, and flexible access.

Description

Technical Field

[0001] The present invention relates to an electric power system, and in particular to a building power distribution system, a mains power control method, and a mains power controller. Background Art

[0002] The electrification of terminal energy consumption and the clean power supply at the source are one of the paths for the low-carbon development of building energy consumption. It has become a consensus to vigorously develop distributed renewable energy around buildings and significantly increase the proportion of non-fossil electricity in the power grid. In order to promote the efficient and full use of renewable electricity, the construction field is developing a new distribution system characterized by "photovoltaic, storage, direct and flexible". Among them, photovoltaic and storage refer to distributed photovoltaic and energy storage in building scenes respectively; direct refers to the low-voltage DC distribution network, which aims to eliminate the AC-DC conversion link in the building, reduce losses, and simplify the grid connection interface; flexible refers to the flexible regulation of loads, which aims to use the flexibility of building loads, actively adjust the load power, and make the load move with the source.

[0003] Most building load flexible adjustment methods are based on platforms such as building automation and the Internet of Things, which require the establishment of wired or wireless physical communication networks and communication protocols between devices and central control. However, the communication network may not cover all building equipment, and the plugging or changing of equipment may involve modifications to the communication protocol or control strategy, and careful maintenance in the later stage is indispensable. For many reasons, the load flexible adjustment method based on the communication system is limited in practical application. The voltage-based load adjustment method does not rely on the communication system, so it has the advantages of reliability and flexibility. Summary of the invention

[0004] The purpose of the present invention is to provide a building power distribution system, a mains power control method and a mains power controller. The technical problem to be solved is to control the mains power without relying on a communication system, improve the reliability of control, and allow plug-and-play of flexible building equipment.

[0005] To solve the above problems, the present invention adopts the following technical solutions: a building power distribution system, including a DC bus, an AC / DC converter group, and a mains power controller, wherein the AC / DC converter group is connected to the municipal power grid through an AC branch, the AC / DC converter group is connected to the DC bus through a DC branch, and the AC / DC converter group is connected to the mains power controller for communication via a communication line;

[0006] The AC / DC converter group is used for the conversion between DC and AC, realizing the power supply from the municipal grid to the DC bus or vice versa, and according to the voltage setting value U set Regulate the voltage of the DC bus;

[0007] The AC power controller obtains the measured voltage value U of the DC bus and the measured AC power value P of the AC branch through the AC / DC converter group, and calculates the voltage setting value U set Then send the voltage setting value U to the AC / DC converter group set , so that the AC / DC converter group can adjust the voltage of the DC bus.

[0008] Furthermore, after obtaining the actual voltage value U, the AC power controller compares whether the actual voltage value U is between the preset voltage upper limit value U max And the preset voltage lower limit U min If the two are equal, then the AC power target value P is obtained. set The power deviation value e=P is calculated after the measured value of the mains power is added set -P and calculated voltage setting value U set ; After the calculation is completed, record the power deviation value e and voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set And set the voltage value U set The AC / DC converter group (2) adjusts the voltage of the DC bus to the voltage setting value U set If yes, then end. If no, then end directly.

[0009] Furthermore, the voltage setting value U set It is calculated by the following formula:

[0010] U set =U set,pre +ΔU set

[0011] Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by an arbitrary monotonically increasing mathematical formula with the power deviation value e as the independent variable.

[0012] Furthermore, the AC / DC converter group includes at least one AC / DC converter module.

[0013] Furthermore, the AC / DC converter group includes at least two AC / DC converter modules, and the AC / DC converter modules are connected in parallel.

[0014] The present invention also discloses a method for controlling mains power, comprising:

[0015] Step S1, preset cycle period;

[0016] Step S2, obtaining a measured voltage value U of the DC bus;

[0017] Step S3: Compare whether the measured voltage value U is within the preset voltage upper limit value U max And the preset voltage lower limit U min If yes, go to step S4, if no, go to step S9 and end;

[0018] Step S4: Obtain the target value of the mains power P set and the measured value of the mains power P;

[0019] Step S5: Calculate the power deviation value e=P set -P;

[0020] Step S6: Calculate the voltage setting value U set ;

[0021] Step S7: Record the power deviation value e and the voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set ;

[0022] Step S8: adjust the voltage of DC bus 1 to the voltage setting value U set ;

[0023] Step S9, end.

[0024] Furthermore, in step S6, the voltage setting value U is calculated. set It is calculated by the following formula:

[0025] U set =U set,pre +ΔU set

[0026] Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by an arbitrary monotonically increasing mathematical formula with the power deviation value e as the independent variable.

[0027] The present invention also discloses a mains power controller, comprising a memory, a processor and a computer program stored in the memory and executable on the processor. The processor reads the computer program in the memory and executes the steps in the mains power control method.

[0028] Compared with the prior art, the present invention uses the voltage of the distribution line as a signal to guide the building equipment to adjust the power, and does not rely on an additional communication system. Therefore, it has the advantages of low cost, high reliability and flexible access. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a building power distribution system of the present invention.

[0030] Figure 2 It is a flow chart of the control method of the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 As shown, the present invention discloses a building power distribution system, including a DC bus 1, an AC / DC converter group 2, and a mains power controller 3, wherein the AC / DC converter group 2 is connected to a municipal power grid 5 through an AC branch 4, the AC / DC converter group 2 is connected to the DC bus 1 through a DC branch 6, and the AC / DC converter group 2 is connected to communicate with the mains power controller 3 via a communication line 7.

[0033] In the present invention, the AC / DC converter group 2 includes at least one AC / DC converter module. When there are more than two AC / DC converter modules, the AC / DC converter modules are connected in parallel to select a corresponding number of AC / DC converter modules according to power requirements.

[0034] The AC / DC converter group 2 is used for converting between direct current and alternating current, realizing that the municipal power grid 4 supplies power to the DC bus 1 or the DC bus 1 supplies power to the municipal power grid. At the same time, according to the voltage setting value U of the municipal power controller 3 set Regulate the voltage of DC bus 1.

[0035] The AC power controller 3 obtains the measured voltage value U of the DC bus 1 and the measured power value P of the AC branch 4 through the AC / DC converter group 2, and calculates the voltage setting value U set Then send the voltage setting value U to AC / DC converter group 2 set , so that the AC / DC converter group 2 adjusts the voltage of the DC bus 1.

[0036] Specifically, the AC power controller 3 obtains the voltage measured value U of the DC bus 1; after obtaining the voltage measured value U, the AC power controller 3 compares whether the voltage measured value U is between the preset voltage upper limit value U max And the preset voltage lower limit U min If the two are equal, then the AC power target value P is obtained. setThe power deviation value e=P is calculated after the measured value of the mains power is added set -P and calculated voltage setting value U set ; After the calculation is completed, record the power deviation value e and voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set And set the voltage value U set The voltage of DC bus 1 is adjusted to the voltage setting value U set If yes, it ends, if no, it ends directly;

[0037] Calculate the voltage setting value U set It is calculated by the following formula:

[0038] U set =U set,pre +ΔU set

[0039] Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by any monotonically increasing mathematical formula with the power deviation value e as the independent variable, such as the existing calculation formula:

[0040] ΔU set =K p ·(ee pre,1 )+K I e+K D ·(e-2e pre,1 +e pre,2 )

[0041] Among them, K p , K I , K D is the preset calculation coefficient.

[0042] The mains power controller 3 performs the above processing once every cycle in a preset cycle.

[0043] like Figure 2 As shown, the present invention also discloses a mains power control method comprising:

[0044] Step S1, preset a cycle period, and execute steps S2-S9 once every cycle period;

[0045] Step S2, obtaining the measured voltage value U of the DC bus 1;

[0046] Step S3: Compare whether the measured voltage value U is within the preset voltage upper limit value U max And the preset voltage lower limit U min If yes, go to step S4, if no, go to step S9 and end;

[0047] Step S4: Obtain the target value of the mains power P set and the measured value of the mains power P;

[0048] Step S5: Calculate the power deviation value e=P set -P;

[0049] Step S6: Calculate the voltage setting value U set ;

[0050] Step S7: Record the power deviation value e and the voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set ;

[0051] Step S8: adjust the voltage of DC bus 1 to the voltage setting value U set ;

[0052] Step S9, end.

[0053] In step S6, the voltage setting value U is calculated. set Calculated by the following formula:

[0054] U set =U set,pre +ΔU set ,

[0055] Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by any monotonically increasing mathematical formula with the power deviation value e as the independent variable, such as the existing calculation formula:

[0056] ΔU set =K p ·(ee pre,1 )+K I e+K D ·(e-2e pre,1 +e pre,2 )

[0057] Among them, K p , K I , K Dis the preset calculation coefficient.

[0058] The following describes the mains power control method in conjunction with the building power distribution system of the present invention:

[0059] Step S1, preset a cycle period through the mains power controller 3, and execute steps S2-S9 once every cycle period;

[0060] Step S2, the mains power controller 3 obtains the measured voltage value U of the DC bus 1 through the AC / DC converter group 2;

[0061] Step S3: The AC power controller 3 compares the measured voltage value U to see whether it is within the preset voltage upper limit value U. max And the preset voltage lower limit U min If yes, go to step S4, if no, go to step S9 and end;

[0062] Step S4: The mains power controller 3 obtains the mains power target value P set and the measured value of the mains power P;

[0063] Step S5: The AC power controller 3 calculates the power deviation value e=P set -P;

[0064] Step S6: The AC power controller 3 calculates the voltage setting value U set ;

[0065] Step S7: The AC power controller 3 records the power deviation value e and the voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set ; and send the voltage setting value Uset to AC / DC converter group 2;

[0066] Step S8: The AC / DC converter group 2 adjusts the voltage of the DC bus 1 to the voltage setting value U set ;

[0067] Step S9, end.

[0068] The present invention also discloses a mains power controller, comprising a memory, a processor and a computer program stored in the memory and executable on the processor. The processor reads the program in the memory and executes the steps in the above-mentioned mains power control method.

[0069] The present invention has the following advantages:

[0070] By obtaining the measured value of the mains power and the measured value of the DC bus voltage, the corresponding voltage setting value is calculated and the voltage of the DC bus is adjusted to the voltage setting value. The voltage of the DC bus is used as a signal to guide the building equipment to actively adjust the power, thereby realizing indirect building mains power control. The mains power controller and AC / DC converter group in the present invention can realize power control of building equipment without relying on the communication system, so it has the advantages of low cost and high reliability; at the same time, the information transmitted by the voltage of the DC bus is not specific to different building equipment, so the building equipment can be plugged in, replaced and plug-and-play, so that it can better adapt to the complex and changeable building scenes in reality, and also reduce the system maintenance cost in actual operation.

Claims

1. A building power distribution system, characterized in that: The invention comprises a DC bus (1), an AC / DC converter group (2), and a mains power controller (3), wherein the AC / DC converter group (2) is connected to a municipal power grid (5) via an AC branch (4), the AC / DC converter group (2) is connected to the DC bus (1) via a DC branch (6), and the AC / DC converter group (2) is connected to the mains power controller (3) for communication via a communication line (7); The AC / DC converter group (2) is used for converting between direct current and alternating current, so as to realize that the municipal power grid (5) supplies power to the direct current bus (1) or the direct current bus (1) supplies power to the municipal power grid, and according to the voltage setting value U set regulating the voltage of the DC bus (1); The mains power controller (3) obtains the measured voltage value U of the DC bus (1) and the measured mains power value P of the AC branch (4) through the AC / DC converter group (2), and calculates the voltage setting value U set Then the voltage setting value U is sent to the AC / DC converter group (2) set so that the AC / DC converter group (2) adjusts the voltage of the DC bus (1); After obtaining the actual voltage value U, the mains power controller (3) compares the actual voltage value U to see whether it is between a preset voltage upper limit value U max And the preset voltage lower limit U min If the two are equal, then the AC power target value P is obtained. set The power deviation value e=P is calculated after the measured value of the mains power is added set -P and calculated voltage setting value U set ; After the calculation is completed, record the power deviation value e and voltage setting value U set , so that w pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set And set the voltage value U set The AC / DC converter group (2) adjusts the voltage of the DC bus (1) to the voltage setting value U set After that, end, if not, end directly; Voltage setting value U set It is calculated by the following formula: U set =U set,pre +ΔU set Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by an arbitrary monotonically increasing mathematical formula with the power deviation value e as the independent variable.

2. The building power distribution system according to claim 1, characterized in that: The AC / DC converter group (2) comprises at least one AC / DC converter module.

3. The building power distribution system according to claim 1, characterized in that: The AC / DC converter group (2) comprises at least two AC / DC converter modules, and the AC / DC converter modules are connected in parallel.

4. A method for controlling the mains power of a building power distribution system using the method of claim 1, characterized in that: include: Step S1, preset cycle period; Step S2, obtaining a measured voltage value U of the DC bus (1); Step S3: Compare whether the measured voltage value U is within the preset voltage upper limit value U max And the preset voltage lower limit U min If yes, go to step S4, if no, go to step S9 and end; Step S4: Obtain the target value of the mains power P set and the measured value of the mains power P; Step S5: Calculate the power deviation value e=P set -P; Step S6: Calculate the voltage setting value U set ; Calculate the voltage setting value U set It is calculated by the following formula: U set =U set,pre +ΔU set Among them, U set is the current voltage setting value, U set,pre is the voltage setting value recorded last time, ΔU set is the voltage correction value; the voltage correction value is calculated by any monotonically increasing mathematical formula with the power deviation value e as the independent variable; Step S7: Record the power deviation value e and the voltage setting value U set , so that pre,2 =e pre,1 , e pre,1 =e,U set,pre =U set ; Step S8: adjust the voltage of the DC bus (1) to the voltage setting value U set ; Step S9, end.

5. A mains power controller, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: The processor reads the computer program in the memory and executes the steps in the mains power control method as claimed in claim 4.

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