Distributed micro-grid energy management system

Abstract

The utility model aims to provide a distributed micro-grid energy management system. The distributed micro-grid energy management system comprises an energy storage battery unit, a direct current load unit, an alternating current load unit, a control management unit, a photovoltaic unit and a grid interface unit, the energy storage battery unit, the power grid interface unit, the photovoltaic unit and the alternating current load unit are connected with the direct current bus; the control management unit comprises a detection module, a control module and a signal conditioning module; the detection module is used for detecting current and voltage signals of the energy storage battery, the direct-current load, the power grid, the photovoltaic battery and the alternating-current load, the output end of the detection module is connected to the input end of the signal conditioning module, the output end of the signal conditioning module is connected with the input end of the control module, and the control module is in communication connection with the dispatching server. The control module outputs PWM control signals to the energy storage battery unit, the DC load unit, the power grid interface unit, the photovoltaic unit and the AC load unit.

Description

TECHNICAL FIELD

[0001] The utility model relates to a power management system especially relates to a kind of distributed microgrid energy management system. BACKGROUND

[0002] New energy such as photovoltaic, wind power is paid more and more attention as clean energy, and is more widely applied, and the output proportion in power system is also increasing day by day.

[0003] New energy forms such as photovoltaic, wind power have the characteristics of intermittency, instability and difficulty in prediction, so the output of new energy inevitably has the characteristics of disturbance; how to realize the balance between the power generation of disturbance and the power consumption of disturbance, to achieve the stable grid connection of new energy, has become an important problem to be solved for large-scale grid connection of new energy.

[0004] In the prior art, the energy management system structure of microgrid composed of wind power, photovoltaic and the like is generally complex and has poor stability, so it is difficult to accurately manage the microgrid.

[0005] Therefore, in order to solve the above technical problems, a new technical means is urgently needed. UTILITY MODEL CONTENT

[0006] Therefore, the utility model aims at providing a kind of distributed microgrid energy management system, can be based on the accurate management of the distributed microgrid composed of wind power, photovoltaic and the like, to effectively ensure the reasonable use and reasonable grid connection of distributed energy, effectively reduce the occurrence of wind curtailment and light curtailment, and the whole system is more simple.

[0007] The utility model aims at providing a kind of distributed microgrid energy management system, comprising energy storage battery unit, direct current load unit, alternating current load unit, control management unit, photovoltaic unit and grid interface unit;

[0008] The energy storage battery unit is connected with direct current bus, the grid interface unit is connected with direct current bus, the photovoltaic unit is connected with direct current bus, and the alternating current load unit is connected with direct current bus;

[0009] The control management unit comprises detection module, control module and signal conditioning module;

[0010] The detection module is used to detect the current and voltage signals of energy storage battery, direct current load, grid, photovoltaic cell and alternating current load, the output end of the detection module is connected to the input end of signal conditioning module, the output end of signal conditioning module is connected with the input end of control module, the control module is communicated and connected with dispatch server, and the control module outputs PWM control signal to energy storage battery unit, direct current load unit, grid interface unit, photovoltaic unit and alternating current load unit.

[0011] Furthermore, the detection module includes a current sensor and a voltage sensor, the output ends of the voltage sensor and the current sensor are connected to the input end of the signal conditioning circuit, and the detection module corresponds one-to-one to the energy storage battery unit, the DC load unit, the AC load unit, the photovoltaic unit and the grid interface unit.

[0012] Furthermore, the signal conditioning circuit includes a voltage conditioning circuit and a current conditioning circuit;

[0013] The voltage conditioning circuit includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2 and a capacitor C3;

[0014] The non-inverting terminal of the operational amplifier U1 is connected to the positive output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected to the negative output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected in parallel through a resistor R3 and a capacitor C2 and then grounded, the non-inverting terminal of the operational amplifier U1 is connected in parallel through a capacitor C1 and a resistor R1 and then connected to the output terminal of the operational amplifier U1, the output terminal of the operational amplifier U1 is connected to one end of the capacitor C3 through the resistor R2, the other end of the capacitor C3 is grounded, and the common connection point between the resistor R2 and the capacitor C3 serves as the output terminal of the voltage conditioning circuit;

[0015] The current conditioning circuit includes an operational amplifier U2, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a capacitor C4;

[0016] The non-inverting terminal of the operational amplifier U2 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the output end of the current sensor as the input end of the current conditioning circuit. The inverting terminal of the operational amplifier U2 is grounded through the resistor R5, and the non-inverting terminal of the operational amplifier U2 is grounded through the capacitor C4. The inverting terminal of the operational amplifier U2 is connected to the output end of the operational amplifier U2 through the resistor R6. The output end of the operational amplifier U2 is connected to one end of the capacitor C5 through the resistor R7, and the other end of the capacitor C5 is grounded. The common connection point between the resistor R7 and the capacitor C5 serves as the output end of the current conditioning circuit.

[0017] Furthermore, the control management unit includes a first controller, a second controller, an AD conversion circuit, a driving circuit, a memory and a clock circuit;

[0018] The first controller is communicatively connected to the second controller, the memory and the clock circuit are communicatively connected to the first controller, the second controller is connected to the output end of the AD conversion circuit, the input end of the AD conversion circuit is connected to the output ends of the voltage conditioning circuit and the current conditioning circuit, the second controller outputs PWM control signals to the energy storage battery unit, the DC load unit, the photovoltaic unit, and the AC load unit, and the first controller is communicatively connected to the scheduling server; the control input end of the drive circuit is connected to the control output end of the second controller, the number of drive circuits is 5, corresponding to the energy storage battery unit, the DC load unit, the photovoltaic unit, the grid interface unit, and the AC load unit, and the drive circuit outputs PWM control signals;

[0019] The first controller is a TMS320C6747 chip and its peripheral circuits;

[0020] The second controller is an EP3C5E14417N chip and its peripheral circuits;

[0021] The AD conversion circuit is an AD7606 chip and its peripheral circuits.

[0022] Furthermore, the energy storage battery unit includes an energy storage battery and a bidirectional DC / DC conversion circuit;

[0023] The positive electrode of the energy storage battery is connected to the first terminal of the bidirectional DC / DC conversion circuit, the second terminal of the bidirectional DC / DC conversion circuit is connected to the DC bus, and the control input end of the bidirectional DC / DC conversion circuit is connected to the control output end of the corresponding drive circuit.

[0024] Furthermore, the grid interface unit includes a bidirectional DC / AC circuit and a grid interface, the DC side of the bidirectional DC / AC circuit is connected to the DC bus, and the AC side of the bidirectional DC / AC circuit is connected to the grid interface. The grid interface is used to inject power into the grid or obtain power from the grid, and the control input end of the bidirectional DC / AC circuit is connected to the control output end of the corresponding drive circuit.

[0025] Furthermore, the DC load unit includes a DC load and a BUCK circuit, wherein the input end of the BUCK circuit is connected to the DC bus, the output end of the BUCK circuit is connected to the DC load, and the control end of the BUCK is connected to the control output end of the corresponding drive circuit.

[0026] Furthermore, the photovoltaic unit includes a photovoltaic power generation unit and a BOOST circuit; the output end of the photovoltaic power generation unit is connected to the input end of the BOOST circuit, the output end of the BOOST circuit is connected to the DC bus, and the control end of the BOOST circuit is connected to the control output end of the corresponding drive circuit.

[0027] Further, the alternating current load unit comprises a unidirectional inverter, an input side of the unidirectional inverter is connected with the direct current bus, an output side of the unidirectional inverter is connected with the alternating current load, and a control end of the unidirectional inverter is connected with a control output end of the corresponding driving circuit.

[0028] Further, the five driving circuits are of the same structure, and each of the driving circuits adopts a 2EDO20I12FA chip and a peripheral circuit thereof.

[0029] The utility model discloses a beneficial effect: through the utility model, can realize accurate management to the distributed microgrid based on wind power, photovoltaic etc. composition, thereby effectively ensure the reasonable utilization of distributed energy and reasonable grid connection, effectively reduce the occurrence of the phenomenon of wind, light, and the whole system is more simple. BRIEF DESCRIPTION OF DRAWINGS

[0030] The utility model will be further described in connection with the drawings and examples:

[0031] Figure 1 It is the structural schematic diagram of the utility model.

[0032] Figure 2 It is the voltage regulation circuit principle diagram of the utility model.

[0033] Figure 3 It is the current regulation circuit principle diagram of the utility model. DETAILED DESCRIPTION

[0034] The utility model will be further described in connection with the drawings and examples:

[0035] The utility model discloses a kind of distributed microgrid energy management systems, including energy storage battery unit, direct current load unit, alternating current load unit, control management unit, photovoltaic unit and grid interface unit;

[0036] The energy storage battery unit is connected with the direct current bus, the grid interface unit is connected with the direct current bus, the photovoltaic unit is connected with the direct current bus, and the alternating current load unit is connected with the direct current bus.

[0037] The control management unit includes detection module, control module and signal conditioning module.

[0038] The detection module is used to detect the current and voltage signals of the energy storage battery, DC load, power grid, photovoltaic cell and AC load. The output end of the detection module is connected to the input end of the signal conditioning module, and the output end of the signal conditioning module is connected to the input end of the control module. The control module is communicatively connected to the dispatching server. The control module outputs PWM control signals to the energy storage battery unit, DC load unit, power grid interface unit, photovoltaic unit and AC load unit. Through the above structure, it is possible to accurately manage the distributed microgrid composed of wind power, photovoltaic power, etc., thereby effectively ensuring the rational utilization and rational grid connection of distributed energy, effectively reducing the occurrence of wind and solar power abandonment, and making the entire system more concise.

[0039] In the examples in this book, the detection module includes a current sensor and a voltage sensor. The output ends of the voltage sensor and the current sensor are connected to the input end of the signal conditioning circuit. The detection module corresponds one-to-one to the energy storage battery unit, the DC load unit, the AC load unit, the photovoltaic unit and the grid interface unit. That is to say, each unit is provided with a detection module, the voltage sensor adopts the existing voltage sensor, and the current sensor adopts the existing Hall sensor.

[0040] In this embodiment, the signal conditioning circuit includes a voltage conditioning circuit and a current conditioning circuit;

[0041] The voltage conditioning circuit includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2 and a capacitor C3;

[0042] The non-inverting terminal of the operational amplifier U1 is connected to the positive output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected to the negative output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected in parallel through a resistor R3 and a capacitor C2 and then grounded, the non-inverting terminal of the operational amplifier U1 is connected in parallel through a capacitor C1 and a resistor R1 and then connected to the output terminal of the operational amplifier U1, the output terminal of the operational amplifier U1 is connected to one end of the capacitor C3 through the resistor R2, the other end of the capacitor C3 is grounded, and the common connection point between the resistor R2 and the capacitor C3 serves as the output terminal of the voltage conditioning circuit;

[0043] The current conditioning circuit includes an operational amplifier U2, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a capacitor C4;

[0044] The non-inverting terminal of op amp U2 is connected to one end of resistor R4. The other end of resistor R4 serves as the input of the current conditioning circuit and is connected to the output of the current sensor. The inverting terminal of op amp U2 is grounded via resistor R5. The non-inverting terminal of op amp U2 is grounded via capacitor C4. The inverting terminal of op amp U2 is connected to the output of op amp U2 via resistor R6. The output of op amp U2 is connected to one end of capacitor C5 via resistor R7. The other end of capacitor C5 is grounded. The common connection point between resistor R7 and capacitor C5 serves as the output of the current conditioning circuit. This structure provides a stable and reliable detection signal to the AD conversion circuit, facilitating subsequent analysis and processing.

[0045] In this embodiment, the control management unit includes a first controller, a second controller, an AD conversion circuit, a driving circuit, a memory and a clock circuit;

[0046] The first controller is communicatively connected to the second controller, the memory and the clock circuit are communicatively connected to the first controller, the second controller is connected to the output end of the AD conversion circuit, the input end of the AD conversion circuit is connected to the output ends of the voltage conditioning circuit and the current conditioning circuit, the second controller outputs PWM control signals to the energy storage battery unit, the DC load unit, the photovoltaic unit, and the AC load unit, and the first controller is communicatively connected to the scheduling server; the control input end of the drive circuit is connected to the control output end of the second controller, the number of drive circuits is 5, corresponding to the energy storage battery unit, the DC load unit, the photovoltaic unit, the grid interface unit, and the AC load unit, and the drive circuit outputs PWM control signals;

[0047] The first controller is a TMS320C6747 chip and its peripheral circuits;

[0048] The second controller is an EP3C5E14417N chip and its peripheral circuits;

[0049] The AD conversion circuit is an AD7606 chip and its peripheral circuits. Through the above structure, the first controller and the second controller respectively perform different functions. The second controller uploads the acquired information to the first controller, which analyzes it according to a pre-set algorithm, such as power flow calculation, and then feeds the calculation results back to the second controller. The second controller controls the drive circuit to generate a corresponding PWM control signal based on the calculation results, thereby allowing the first and second controllers to divide the work and cooperate, which can improve processing and control efficiency and reduce load. The first controller uploads the analysis results to the scheduling server. Of course, the first controller also loads and issues control instructions output by the scheduling server.

[0050] In this embodiment, the energy storage battery unit includes an energy storage battery and a bidirectional DC / DC conversion circuit;

[0051] The positive electrode of the energy storage battery is connected to the first terminal of the bidirectional DC / DC conversion circuit, the second terminal of the bidirectional DC / DC conversion circuit is connected to the DC bus, and the control input end of the bidirectional DC / DC conversion circuit is connected to the control output end of the corresponding drive circuit. The bidirectional DC / DC conversion circuit adopts an existing circuit, such as two bridge circuits composed of IGBTs, which are coupled and connected by a transformer in the middle to achieve isolation; the gate of the IGBT serves as the control input end of the bidirectional DC / DC conversion circuit.

[0052] In this embodiment, the grid interface unit includes a bidirectional DC / AC circuit and a grid interface. The DC side of the bidirectional DC / AC circuit is connected to the DC bus, and the AC side of the bidirectional DC / AC circuit is connected to the grid interface. The grid interface is used to inject power into the grid or obtain power from the grid. The control input end of the bidirectional DC / AC circuit is connected to the control output end of the corresponding drive circuit. The bidirectional DC / AC circuit can use an existing circuit and is not described in detail here.

[0053] In this embodiment, the DC load unit includes a DC load and a BUCK circuit, wherein the input end of the BUCK circuit is connected to the DC bus, the output end of the BUCK circuit is connected to the DC load, and the control end of the BUCK is connected to the control output end of the corresponding drive circuit.

[0054] The photovoltaic unit includes a photovoltaic power generation unit and a BOOST circuit; the output end of the photovoltaic power generation unit is connected to the input end of the BOOST circuit, the output end of the BOOST circuit is connected to the DC bus, and the control end of the BOOST circuit is connected to the control output end of the corresponding drive circuit. Among them, the BUCK circuit and the BOOST circuit are both existing technologies and will not be described in detail here. Among them, the photovoltaic power generation unit includes a photovoltaic cell and a photovoltaic controller, which are existing technologies.

[0055] In this embodiment, the AC load unit includes a unidirectional inverter, the input side of the unidirectional inverter is connected to the DC bus, the output side of the unidirectional inverter is connected to the AC load, and the control end of the unidirectional inverter is connected to the control output end of the corresponding drive circuit.

[0056] In this embodiment, the five driving circuits have the same structure, and all of the driving circuits use a 2EDO20I12FA chip and its peripheral circuits.

[0057] Finally, it is explained that the above embodiments are only used to illustrate the technical solutions of the present application and are not limited. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application. The technical solutions of the present application should be covered in the scope of the claims of the present application.

Claims

1. A distributed microgrid energy management system, characterized by: Including energy storage battery unit, DC load unit, AC load unit, control management unit, photovoltaic unit and grid interface unit; The energy storage battery unit is connected to the DC bus, the grid interface unit is connected to the DC bus, the photovoltaic unit is connected to the DC bus, and the AC load unit is connected to the DC bus; The control management unit includes a detection module, a control module and a signal conditioning module; The detection module is used to detect the current and voltage signals of the energy storage battery, DC load, power grid, photovoltaic cell and AC load. The output end of the detection module is connected to the input end of the signal conditioning module, and the output end of the signal conditioning module is connected to the input end of the control module. The control module is communicatively connected to the scheduling server, and the control module outputs PWM control signals to the energy storage battery unit, DC load unit, power grid interface unit, photovoltaic unit and AC load unit.

2. The distributed microgrid energy management system according to claim 1, characterized in that: The detection module includes a current sensor and a voltage sensor, the output ends of the voltage sensor and the current sensor are connected to the input end of the signal conditioning circuit, and the detection module corresponds one-to-one to the energy storage battery unit, the DC load unit, the AC load unit, the photovoltaic unit and the grid interface unit.

3. The distributed microgrid energy management system according to claim 2, characterized in that: The signal conditioning circuit includes a voltage conditioning circuit and a current conditioning circuit; The voltage conditioning circuit includes an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2 and a capacitor C3; The non-inverting terminal of the operational amplifier U1 is connected to the positive output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected to the negative output terminal of the voltage sensor, the inverting terminal of the operational amplifier U1 is connected in parallel through a resistor R3 and a capacitor C2 and then grounded, the non-inverting terminal of the operational amplifier U1 is connected in parallel through a capacitor C1 and a resistor R1 and then connected to the output terminal of the operational amplifier U1, the output terminal of the operational amplifier U1 is connected to one end of the capacitor C3 through the resistor R2, the other end of the capacitor C3 is grounded, and the common connection point between the resistor R2 and the capacitor C3 serves as the output terminal of the voltage conditioning circuit; The current conditioning circuit includes an operational amplifier U2, a resistor R4, a resistor R5, a resistor R6, a resistor R7 and a capacitor C4; The non-inverting terminal of the operational amplifier U2 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the output end of the current sensor as the input end of the current conditioning circuit. The inverting terminal of the operational amplifier U2 is grounded through the resistor R5, and the non-inverting terminal of the operational amplifier U2 is grounded through the capacitor C4. The inverting terminal of the operational amplifier U2 is connected to the output end of the operational amplifier U2 through the resistor R6. The output end of the operational amplifier U2 is connected to one end of the capacitor C5 through the resistor R7, and the other end of the capacitor C5 is grounded. The common connection point between the resistor R7 and the capacitor C5 serves as the output end of the current conditioning circuit.

4. The distributed microgrid energy management system according to claim 3, characterized in that: The control management unit includes a first controller, a second controller, an AD conversion circuit, a driving circuit, a memory and a clock circuit; The first controller is communicatively connected to the second controller, the memory and the clock circuit are communicatively connected to the first controller, the second controller is connected to the output end of the AD conversion circuit, the input end of the AD conversion circuit is connected to the output ends of the voltage conditioning circuit and the current conditioning circuit, the second controller outputs PWM control signals to the energy storage battery unit, the DC load unit, the photovoltaic unit, and the AC load unit, and the first controller is communicatively connected to the scheduling server; the control input end of the drive circuit is connected to the control output end of the second controller, the number of drive circuits is 5, corresponding to the energy storage battery unit, the DC load unit, the photovoltaic unit, the grid interface unit, and the AC load unit, and the drive circuit outputs PWM control signals; The first controller is a TMS320C6747 chip and its peripheral circuits; The second controller is an EP3C5E14417N chip and its peripheral circuits; The AD conversion circuit is an AD7606 chip and its peripheral circuits.

5. The distributed microgrid energy management system according to claim 4, characterized in that: The energy storage battery unit includes an energy storage battery and a bidirectional DC / DC conversion circuit; The positive electrode of the energy storage battery is connected to the first terminal of the bidirectional DC / DC conversion circuit, the second terminal of the bidirectional DC / DC conversion circuit is connected to the DC bus, and the control input end of the bidirectional DC / DC conversion circuit is connected to the control output end of the corresponding drive circuit.

6. The distributed microgrid energy management system according to claim 4, characterized in that: The grid interface unit includes a bidirectional DC / AC circuit and a grid interface. The DC side of the bidirectional DC / AC circuit is connected to the DC bus, and the AC side of the bidirectional DC / AC circuit is connected to the grid interface. The grid interface is used to inject power into the grid or obtain power from the grid. The control input end of the bidirectional DC / AC circuit is connected to the control output end of the corresponding drive circuit.

7. The distributed microgrid energy management system according to claim 4, characterized in that: The DC load unit includes a DC load and a BUCK circuit. The input end of the BUCK circuit is connected to the DC bus, the output end of the BUCK circuit is connected to the DC load, and the control end of the BUCK is connected to the control output end of the corresponding drive circuit.

8. The distributed microgrid energy management system according to claim 4, characterized in that: The photovoltaic unit includes a photovoltaic power generation unit and a BOOST circuit; the output end of the photovoltaic power generation unit is connected to the input end of the BOOST circuit, the output end of the BOOST circuit is connected to the DC bus, and the control end of the BOOST circuit is connected to the control output end of the corresponding drive circuit.

9. The distributed microgrid energy management system according to claim 4, characterized in that: The AC load unit includes a unidirectional inverter, the input side of the unidirectional inverter is connected to the DC bus, the output side of the unidirectional inverter is connected to the AC load, and the control end of the unidirectional inverter is connected to the control output end of the corresponding drive circuit.

10. The distributed microgrid energy management system according to claim 4, characterized in that: The five drive circuits have the same structure, and all drive circuits use the 2EDO20I12FA chip and its peripheral circuits.

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