Energy control system, energy control method and related device

Abstract

The invention discloses an energy control system, an energy control method and a related device, and relates to the field of water heater power supply. According to the water heater, the energy storage unit can store the electric energy which is generated by the photovoltaic module and is not used by the water heater, and / or store the electric energy obtained from the power grid, so that when the water heater needs to be heated, the alternating current output by the power grid is converted into the first electric energy through the alternating current conversion unit; the power optimization unit is used for converting electric energy output by the photovoltaic module into second electric energy, the energy storage unit is used for outputting third electric energy, at least two of the second electric energy and the third electric energy are selected for providing electric energy for the water heater, and therefore in different scenes, a proper water heater power supply mode can be selected; electric energy stored in the energy storage unit and electric energy provided by the power grid can be used for heating the water heater, heating reliability of the water heater is improved, electric energy obtained from the power grid is reduced, and cost is saved.

Description

Technical Field

[0001] The present application relates to the field of power supply, and more specifically, to an energy control system, an energy control method and related devices. Background Art

[0002] In actual scenarios, grid power is generally used to power electrical equipment, such as providing power for water heaters. However, with the development of photovoltaic modules, photovoltaic modules can use solar energy to generate electricity, which can also be used to provide power for electrical equipment.

[0003] Then, when both photovoltaic modules and power grids are able to provide electrical energy to electrical equipment, how to improve the reliability of power supply is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In view of this, the present application provides an energy control system, an energy control method and related devices to solve the problem of urgently needing to improve power supply reliability.

[0005] In order to solve the above technical problems, this application adopts the following technical solutions:

[0006] An energy control system, comprising:

[0007] An AC conversion unit, a power optimization unit, an energy storage unit, a coupling unit and a controller; the AC conversion unit and the power optimization unit are directly connected to the coupling unit respectively, the energy storage unit is directly or indirectly connected to the coupling unit, and the controller is communicatively connected to the AC conversion unit, the power optimization unit, the coupling unit and the energy storage unit respectively;

[0008] The controller is used to control at least two units among the AC conversion unit, the power optimization unit and the energy storage unit to perform electric energy output operation;

[0009] The AC conversion unit is used to convert the AC power output by the power grid into the first electric energy based on the control instruction of the controller;

[0010] The power optimization unit is used to convert the electric energy output by the photovoltaic assembly into second electric energy based on the control instruction of the controller;

[0011] The energy storage unit is used to output the third electric energy based on the control instruction of the controller; the electric energy stored in the energy storage unit includes: the electric energy generated by the photovoltaic assembly and not used by the electric device, and / or the electric energy obtained from the power grid;

[0012] The coupling unit is used to couple the electric energy output by the at least two units to obtain and output the total electric energy to the electric device.

[0013] Optionally, the energy storage unit is arranged between the photovoltaic component and the power optimization unit.

[0014] Optionally, when the energy storage unit is directly connected to the coupling unit, or the energy storage unit is arranged between the photovoltaic assembly and the power optimization unit, the energy storage unit includes a power conversion topology structure and an energy storage battery pack;

[0015] The power conversion topology is used to implement the charging and discharging operations of the energy storage battery pack.

[0016] Optionally, the energy storage unit is disposed between the power optimization unit and the coupling unit, and is connected to the coupling unit via an electrical isolation unit.

[0017] Optionally, the energy storage unit includes an energy storage battery pack;

[0018] Alternatively, the energy storage unit includes both a power conversion topology structure and an energy storage battery pack; the power conversion topology structure is used to implement charging and discharging operations of the energy storage battery pack.

[0019] Optionally, the energy control system further includes:

[0020] An active heating regulating unit located between the coupling unit and the electrical device;

[0021] The active heating regulation unit is used to regulate the voltage value outputted from the coupling unit to the electrical device, so as to achieve stepless heating regulation of the electrical device.

[0022] An energy system comprises the above energy control system and electrical equipment.

[0023] An energy control method is applied to a controller in the above energy control system, and the energy control method comprises:

[0024] Control at least two of the AC conversion unit, the power optimization unit and the energy storage unit to perform electric energy output operation.

[0025] Optionally, controlling at least two of the AC conversion unit, the power optimization unit, and the energy storage unit to perform an electric energy output operation includes:

[0026] Controlling the AC conversion unit to operate so that the AC conversion unit converts the AC power output by the power grid into the first electric energy;

[0027] After the voltage of the coupling unit is stabilized, controlling the power optimization unit to operate so that the power optimization unit converts the electric energy output by the photovoltaic assembly into the second electric energy;

[0028] Obtaining the output power of the power optimization unit;

[0029] When the output power of the power optimization unit is less than a first threshold, controlling the power optimization unit to stop running, and controlling the energy storage unit to output a third electric energy;

[0030] When the output power of the power optimization unit is greater than the first threshold and less than the second threshold, controlling the energy storage unit to output a third electric energy;

[0031] Adjust the operating state of at least one unit that outputs electric energy among the AC conversion unit, the power optimization unit and the energy storage unit.

[0032] Optionally, controlling the energy storage unit to output a third electric energy includes:

[0033] Obtaining the remaining power of the energy storage unit;

[0034] When the remaining power is greater than the power threshold and the difference between the current parameter and the first parameter threshold is greater than the difference threshold, the energy storage unit is controlled to output the third electric energy according to the maximum power of the energy storage unit.

[0035] Optionally, after controlling the energy storage unit to output the third electric energy, the method further includes:

[0036] If the remaining power of the energy storage unit is less than the power threshold, the energy storage unit is controlled to stop running.

[0037] Optionally, adjusting the operating state of at least one unit outputting electric energy among the AC conversion unit, the power optimization unit, and the energy storage unit comprises:

[0038] If only the AC conversion unit and the power optimization unit output electric energy, obtain the operating parameters of the electric equipment during operation, and adjust the operating power of the power optimization unit according to the operating parameters until the power of the photovoltaic module reaches the maximum power point;

[0039] If the AC conversion unit, the power optimization unit and the energy storage unit all output electrical energy, the output power of the energy storage unit is adjusted to a set power.

[0040] Optionally, the set power is the maximum output power of the energy storage unit, the power that makes the grid output power a specified value, the difference between the rated output power of the power optimization unit and the actual power generated by the photovoltaic component, or the difference between the rated output power of the electrical isolation unit and the actual output power of the power optimization unit.

[0041] Optionally, it also includes:

[0042] When the electric device does not need electric energy and the current time is in the energy storage charging time period, the power grid is controlled to provide electric energy to the energy storage unit.

[0043] An energy conversion device is used to execute the above energy control method.

[0044] The present application discloses an energy control system, an energy control method and related devices. In the present application, the energy storage unit can store the electric energy generated by the photovoltaic module that is not used by the electrical equipment, and / or store the electric energy obtained from the power grid, so that when the water heater needs to be heated, at least two items are selected from using the AC conversion unit to convert the AC power output by the power grid into the first electric energy, using the power optimization unit to convert the electric energy output by the photovoltaic module into the second electric energy, and using the energy storage unit to output the third electric energy to provide electric energy for the electrical equipment, so that in different scenarios, a suitable power supply method can be selected. For example, when there is insufficient light, the electric energy stored in the energy storage unit and the electric energy provided by the power grid can be used to power the electrical equipment, thereby improving the power supply reliability, reducing the electric energy obtained from the power grid, and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0046] Figure 1 It is a structural schematic diagram of an energy system in the related art;

[0047] Figure 2 A schematic diagram of the structure of an energy control system provided in an embodiment of the present application;

[0048] Figure 3 A schematic diagram of the structure of another energy control system provided in an embodiment of the present application;

[0049] Figure 4 A control logic diagram of an energy control system provided in an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the structure of another energy control system provided in an embodiment of the present application;

[0051] Figure 6 A schematic diagram of the structure of another energy control system provided in an embodiment of the present application;

[0052] Figure 7 A control logic diagram of another energy control system provided in an embodiment of the present application;

[0053] Figure 8 A flow chart of an energy control method provided in an embodiment of the present application;

[0054] Fig. 9 A waveform diagram of a heating control process provided in an embodiment of the present application;

[0055] Fig.10 A waveform diagram of another heating control process provided in an embodiment of the present application;

[0056] Fig.11 A flow chart of a heating control process provided in an embodiment of the present application;

[0057] Fig.12 Another heating control process flow chart provided for an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] In actual scenarios, grid power is generally used to power electrical equipment, such as providing power for water heaters. However, with the development of photovoltaic modules, photovoltaic modules can use solar energy to generate electricity, which can also be used to provide power for electrical equipment.

[0060] Then, when both photovoltaic modules and power grids are able to provide electrical energy to electrical equipment, how to improve the reliability of power supply is a technical problem that technical personnel in this field urgently need to solve.

[0061] In the related technology, taking the electrical equipment as a water heater as an example, the current photovoltaic water heater architecture is a dual heating structure with separate power supply and operation on the photovoltaic DC side and the grid AC side, and the photovoltaic module does not control the output and is not in the best working state. The specific implementation can be achieved by Figure 1 The structure shown utilizes both the electricity generated by the photovoltaic modules and the electricity from the grid to perform water heater heating operations.

[0062] Figure 1In the example, the water heater is provided with two heating bodies, namely the DC heating body and the AC heating body. On the DC heating body side, the photovoltaic modules are connected in series, and the electric energy generated by the photovoltaic modules in the photovoltaic panels is collected together through the junction box and then output to the DC heating body for heating. On the AC heating body side, the electric energy generated by the power grid is output to the AC heating body through the control switch. At this time, the DC heating body and the AC heating body heat the water heater at the same time, realizing the dual heating of cold water.

[0063] against Figure 1 The heating structure has the following technical defects:

[0064] 1. The DC side and AC side are completely separated, and two sets of heating elements need to be configured. The heating elements are redundant, which increases the system cost;

[0065] 2. The photovoltaic panels on the DC side must be connected in series to form high-voltage DC. The photovoltaic panels are uncontrolled power generation, and the combiner box only controls the on-off of the high-voltage DC. Therefore, the power generation efficiency of the photovoltaic panels is not maximized, the photovoltaic efficiency is low, and the maximum performance of the photovoltaic components cannot be brought into play;

[0066] 3. The DC side is directly connected to the heating element without isolation. Long-term operation may cause the risk of DC and AC short circuit, which may lead to high safety risk of electricity use.

[0067] 4. There is no direct coupling between the DC side and the AC side, which cannot effectively regulate the power consumption of the grid and has low economic benefits;

[0068] 5. When the water temperature reaches the set maximum temperature, the photovoltaic components are idle and the solar energy is not fully utilized. In addition, solar energy cannot be used for heating during the peak period of hot water use at night. Heating can only be done through the AC power of the power grid. The proportion of solar green electricity used is low and the economic efficiency is poor.

[0069] To this end, the embodiment of the present application proposes a single heating body architecture with flexible AC-DC coupling with energy storage, which couples photovoltaic power and grid power to achieve direct coupling output of DC and AC in a single heating body, and the two coordinate power output to improve economic efficiency. In addition, by adding an energy storage unit to store the excess power output by the photovoltaic module and the power obtained from the grid during the valley power phase, the power in the energy storage unit can be used to power the water heater when there is insufficient light or at night, or during the peak power phase, so that solar energy can be stored during non-heating time periods for heating the water heater in poor light or at night, which can reduce the power obtained from the grid and improve economic efficiency.

[0070] In addition, after the photovoltaic panels and the power grid are coupled, the number of heating bodies is reduced, which improves the cost advantage of the system.

[0071] In addition, the embodiments of the present invention can actively optimize the output power of the photovoltaic module, ensure that the photovoltaic module operates at the maximum power point, greatly improve the utilization rate of the photovoltaic module, and achieve maximum energy output on the photovoltaic module side.

[0072] In addition, electrical isolation is achieved between the photovoltaic DC low voltage and the grid AC high voltage, which improves the safety of equipment operation.

[0073] In addition, according to the thermal energy demand, the power on the DC side and AC side is adjusted to achieve optimal thermal energy control.

[0074] Based on the above content, an embodiment of the present application provides an energy control system, which can be called a heat energy management system (Heart Energy Management Systerm, HEMS). Figure 2 , the energy control system may include:

[0075] An AC conversion unit 11, a power optimization unit 12, an energy storage unit 15, a coupling unit 13 and a controller 14; the AC conversion unit 11 and the power optimization unit 12 are directly connected to the coupling unit 13 respectively, and the energy storage unit 15 is directly or indirectly connected to the coupling unit 13. Figure 2 In the embodiment, the energy storage unit 15 is directly connected to the coupling unit 13, and the embodiment in which the energy storage unit 15 is indirectly connected to the coupling unit 13 refers to other embodiments.

[0076] In addition, the controller 14 is communicatively connected with the AC conversion unit 11 , the power optimization unit 12 , the coupling unit 13 , and the energy storage unit 15 , respectively. Figure 2 The communication connection structure is not shown. Through the communication connection, the controller 14 can obtain the operating data of the AC conversion unit 11, the power optimization unit 12, the coupling unit 13, and the energy storage unit 15, so as to adjust the operating status of the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15.

[0077] In actual scenarios, the AC conversion unit 11 is connected to the power grid, and based on the control instructions of the controller, converts the AC power output from the power grid into the first electric energy. More specifically, the AC conversion unit 11 converts the AC power of the power grid into DC power through a power electronic converter and outputs it to the coupling unit 13.

[0078] In one implementation, the AC conversion unit 11 includes: a controllable conversion unit or an uncontrollable conversion unit.

[0079] The controllable conversion unit includes an industrial frequency rectifier conversion circuit or a high frequency chopper conversion circuit constructed by active switching devices; the uncontrollable conversion unit includes a rectifier or a rectifier circuit constructed by discrete devices. In one implementation, an uncontrollable conversion unit can be selected for cost considerations. If cost is not considered, one of the controllable conversion unit and the uncontrollable conversion unit can be selected.

[0080] The power optimization unit 12 is connected to the photovoltaic modules (PV+ and PV- represent the positive and negative poles respectively). The photovoltaic modules mainly convert solar energy into electrical energy, and the number of photovoltaic modules is configured according to actual needs. In actual scenarios, if the photovoltaic modules are connected in series, the voltage of the photovoltaic modules after series connection is higher. If there is a risk of electric shock later, it will have a greater impact on human safety. Therefore, in one implementation of the present application, the photovoltaic modules are connected in parallel and connected to the power optimization unit 12. After the photovoltaic modules are connected in parallel, the parallel current is larger and the parallel voltage does not change. Therefore, the impact on human safety in the event of subsequent electric shock can be avoided. In addition, the parallel connection of photovoltaic modules is also more suitable for low-power application scenarios such as homes.

[0081] In one implementation, the power electronic converter in the power optimization unit 12 adopts an isolated topology or a non-isolated topology. Specifically, the power optimization unit 12 adjusts the working state of the photovoltaic module through the power electronic converter to keep the photovoltaic module at the maximum power point. The power electronic converter can be an isolated topology to ensure the electrical isolation of the photovoltaic module and the HEMS and the product contactable shell, and achieve safer electrical contact. Its conventional topologies mainly include flyback converter Flyback, LLC (LLC resonant converter), DAB (Dual Active Bridge, dual active bridge converter), CLLLC (CLLC resonant converter), dual-tube forward, etc. At the same time, the power electronic converter can also be a non-isolated topology. Common topologies mainly include boost chopper Boost, buck Buck, FSBB (Four Switching BuckBoost four-tube Buck Boost), etc. Which structure to choose specifically can be based on actual configuration.

[0082] After the photovoltaic modules are connected in parallel, the AC power is output to the power optimization unit 12. The power optimization unit 12 converts the power output by the photovoltaic modules into the second power based on the control instruction of the controller. At the same time, the AC conversion unit 11 converts the AC power output by the power grid into the first power.

[0083] With respect to the energy storage unit 15, when an electrical device, such as a water heater, does not need to be heated, if the photovoltaic module can generate excess electrical energy, the electrical energy can be stored in the energy storage unit 15. In addition to storing the excess solar energy generated by the photovoltaic module, the energy storage unit 15 can also draw electricity from the power grid when the electricity price is at a valley price, and discharge it for heating the water heater when the electricity price is at a peak price, thereby achieving peak shaving and valley filling of the power grid electricity price. Therefore, in the embodiment of the present invention, the electrical energy stored in the energy storage unit 15 includes: the electrical energy generated by the photovoltaic module that is not used by the electrical device, and / or the electrical energy obtained from the power grid.

[0084] Taking the water heater as an example, when electric energy is stored in the energy storage unit 15, the electric energy in the energy storage unit 15 can be used to heat the water heater later. At this time, the energy storage unit 15 outputs the third electric energy based on the control instruction of the controller. For example, at night or when there is insufficient light during the day, the photovoltaic module generates less electric energy. At this time, the electric energy in the energy storage unit 15 can be used to heat the water heater to reduce the amount of electricity obtained from the power grid and reduce costs.

[0085] When the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15 can all provide electric energy, the controller 14 can select at least two of the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15 based on actual needs, such as the current electricity price, the current light conditions, whether it is night, etc., to control at least two of the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15 to perform electric energy output operations.

[0086] Since the AC conversion unit 11 and the power optimization unit 12 are connected to the coupling unit 13, and the energy storage unit 15 is directly or indirectly connected to the coupling unit 13, the AC conversion unit 11 outputs the first electric energy to the coupling unit 13, the power optimization unit 12 outputs the second electric energy to the coupling unit 13, and the energy storage unit 15 also outputs the third electric energy to the coupling unit 13. However, in actual applications, only at least two of the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15 may output electric energy. At this time, the coupling unit 13 couples the electric energy output by the at least two units to obtain and output the total electric energy to the electrical equipment, such as a water heater. For example, only the AC conversion unit 11 and the power optimization unit 12 may be running. At this time, the coupling unit 13 couples the first electric energy and the second electric energy to obtain the total electric energy. In addition, if the AC conversion unit 11, the power optimization unit 12, and the energy storage unit 15 are all running, the coupling unit 13 couples the first electric energy, the second electric energy, and the third electric energy to obtain the total electric energy. In addition, if only the power optimization unit 12 and the energy storage unit 15 are in operation, the coupling unit only couples the second electric energy and the third electric energy to obtain the total electric energy. In addition, if only the AC conversion unit 11 and the energy storage unit 15 are in operation, the coupling unit 13 only couples the first electric energy and the third electric energy to obtain the total electric energy.

[0087] In one implementation, the coupling unit 13 includes a capacitor, and specifically couples the energy output by each unit of the output electric energy through a device such as a capacitor, that is, at least two of the photovoltaic solar energy, the power grid electric energy, and the power storage unit 15 electric energy are combined together for unified allocation and management. The coupling unit 13 has active adaptability, and can achieve mutual compensation of photovoltaic output energy, power grid output energy, and energy storage unit output energy, and can meet all-weather heating, without the need for human intervention in the heating mode and automatically executes in a mode of giving priority to photovoltaic output heating.

[0088] The coupling unit 13 outputs the total electric energy to an electrical device, such as a water heater. In one implementation, the water heater is a water storage device including a heating body. Electricity is taken from the coupling unit 13 and output to the heating body, so that the heating body in the water heater uses the total electric energy for heating operation, thereby heating the cold water. During the heating process of the heating body, the water temperature will be transmitted to the controller 14 in the HEMS.

[0089] In this embodiment, the energy storage unit is capable of storing the electric energy generated by the photovoltaic module that is not used by the electrical equipment, and / or storing the electric energy obtained from the power grid, so that when the water heater needs to be heated, at least two items are selected from the following: using the AC conversion unit to convert the AC power output by the power grid into the first electric energy, using the power optimization unit to convert the electric energy output by the photovoltaic module into the second electric energy, and using the energy storage unit to output the third electric energy to provide electric energy for the electrical equipment. In this way, a suitable power supply method can be selected in different scenarios. For example, when there is insufficient light, the electric energy stored in the energy storage unit and the electric energy provided by the power grid can be used to power the electrical equipment, thereby improving the power supply reliability, reducing the electric energy obtained from the power grid, and saving costs.

[0090] In addition, an energy storage unit is added, which can store excess solar energy in the energy storage unit and discharge it to heat the heating body when there is no solar energy, thereby making full use of solar energy.

[0091] In addition, through the electrical isolation design of the power optimization unit, electrical isolation between the photovoltaic DC low voltage and the grid AC high voltage is achieved, which improves the safety of equipment operation and reduces the risk of electric shock to the equipment.

[0092] In addition, photovoltaic heating and AC heating share the same heating body through a coupling unit, which reduces the number of heating bodies and improves the cost advantage of the system.

[0093] In one implementation, based on the structure of the above energy control system, Figure 3 As shown, the energy control system may further include a heating active regulation unit 16 located between the coupling unit and the electrical equipment.

[0094] In actual scenarios, taking the water heater as an example, the heating element in the water heater is a passive resistive heating element. That is, when electrical energy (voltage, current and power) is input to the heating element, the heating element performs heating operation according to the electrical energy and does not have an active adjustment function. In order to perform heating operation more flexibly, Figure 2 On the basis of the active heating regulating unit 16, the active heating regulating unit 16 is added. The input end of the active heating regulating unit 16 is connected to the output end of the coupling unit 13, and the output end of the active heating regulating unit 16 is connected to the heating body, so that electric energy can be input into the heating body.

[0095] In actual scenarios, the active heating adjustment unit 16 is used to adjust the voltage value output by the coupling unit 13 to the electrical device, such as a water heater, to achieve stepless heating adjustment of the electrical device, such as the heating body in the water heater.

[0096] To elaborate, the active heating regulating unit 16 is controlled by the HEMS control program in the controller 14, which requires the HEMS control program to have more energy-saving considerations for the heating of the heating body. When the water temperature is close to the set temperature, the temperature of the heating body is changed by the active heating regulating unit 16, thereby saving the electric energy obtained from the power grid, and the temperature of the heating body can also be infinitely regulated. In addition, the HEMS algorithm can also be used to achieve that the energy of the coupling unit in certain cases comes from the solar energy of the photovoltaic module, saving electricity bills for users.

[0097] Specifically, the HEMS control program can send an initial voltage value and a voltage change gradient. For example, if the voltage output by the coupling unit 13 to the heating active adjustment unit 16 is 300V, at this time, the current water temperature is close to the temperature value set by the user. Therefore, if 300V is used to heat the heating body, the temperature will rise rapidly and it is easy to exceed the temperature value set by the user. Therefore, the HEMS control program can calculate an initial voltage value and a voltage change gradient according to the difference between the current temperature and the temperature value set by the user. For example, the initial voltage value can be 100V, and the voltage change gradient is -0.1V. At this time, after receiving the 300V voltage output by the coupling unit 13, the heating active adjustment unit 16 does not output all the 300V voltage to the heating body, but only outputs 100V of the voltage to the heating body, and the voltage output to the heating body gradually decreases according to the gradient of -0.1V, such as 99.9V in the next cycle, 99.8V in the next cycle..., as the voltage continues to decrease, the heating temperature of the heating body increases slowly, and then it can gradually approach the temperature value set by the user when it is close to the temperature value set by the user, so as to avoid the situation where the temperature exceeds the set value. In addition, since the voltage change gradient set in the present application is small, the temperature of the heating body can be slowly increased to achieve stepless temperature regulation, and avoid the situation where the temperature exceeds the set value due to large temperature changes.

[0098] When the heating active regulation unit 16 is used to regulate the voltage of the heating body, since the voltage required by the heating body is reduced, the electric energy from the grid side can be reduced, that is, the output electric energy of the AC conversion unit 11 can be reduced. At this time, the theoretical voltage value of the first electric energy output by the AC conversion unit 11 can be calculated using the grid voltage, the output current of the power optimization unit 12, the output current of the AC conversion unit 11, the voltage of the coupling unit 13, the output voltage of the energy storage unit 15, the voltage at both ends of the heating body, the current flowing through the heating body, the temperature of the heating body, the water temperature, the water volume and other data, and the voltage of the first electric energy output by the AC conversion unit 11 can be adjusted according to the theoretical voltage value.

[0099] exist Figure 3Based on the architecture, the operation process of the power optimization unit 12, the AC conversion unit 11, the energy storage unit 15, and the heating active adjustment unit 16 needs to be controlled by the controller 14. The specific control logic can refer to Figure 4 shown.

[0100] The controller 14 has a built-in HEMS control program as a core computing and scheduling unit. The HEMS control program integrates data and instruction collection, control and protection of each unit, and energy allocation to comprehensively realize hybrid heating of the water heater by photovoltaic, power grid and energy storage units.

[0101] The HEMS control program can obtain a thermal energy reference value. In one implementation, the thermal energy reference value is the maximum water temperature value set by the user, such as 50°C, 60°C, etc. In addition, during the process of the heating body heating to generate thermal energy, the HEMS control program can also collect the heat of the thermal energy and the water temperature of the water in the current water heater.

[0102] In addition, the HEMS control program can also collect the voltage and current of the photovoltaic module, the grid voltage, the output current of the power optimization unit 12, the output current of the AC conversion unit 11, the voltage of the coupling unit 13, the output voltage of the energy storage unit 15, the voltage at both ends of the heating body, the current flowing through the heating body, the temperature of the heating body, the water temperature, the water volume and other data, and use the above data to intelligently determine the optimal power output of the power optimization unit 12, and perform power control on the power optimization unit 12 to achieve the maximum power output of the photovoltaic module. At the same time, the output of the AC conversion unit 11 is automatically adjusted according to the required heat to change the energy obtained from the grid, so as to ensure that the electric energy required for electric heating mainly comes from solar energy, so as to achieve better economic benefits. In addition, the HEMS control program can also control the output of electric energy in the energy storage unit 15. When the sunlight is insufficient or the peak electricity price is high, the electric energy in the energy storage unit 15 is used to supply power to achieve the best economic benefits.

[0103] The heating active regulation unit 16 is arranged between the coupling unit and the heating body, and regulates the voltage outputted from the coupling unit 13 to the heating body, thereby realizing stepless regulation of temperature. The heating active regulation unit 16 can communicate with the HEMS control program, so that the HEMS control program controls the voltage regulation process of the heating active regulation unit 16. The rest of the control logic refers to the corresponding description above.

[0104] Based on the structure of the energy control system described above, the internal structure and connection relationship of the energy storage unit 15 may be different depending on the location of the energy storage unit 15. The details are as follows:

[0105] 1. The energy storage unit is directly connected to the coupling unit.

[0106] When the energy storage unit is directly connected to the coupling unit, its specific implementation refers to Figure 2 As shown. By placing the energy storage unit in different positions, different requirements are generated for the energy storage unit. When the energy storage unit is directly connected to the coupling unit, the voltage of the coupling unit is high voltage, and the energy storage unit needs to achieve a large range of high and low voltage conversion while having electrical isolation power. At this time, the energy storage unit includes a power conversion topology and an energy storage battery pack. Among them, the power conversion topology can be FSBB and SR Boost (Synchronous Rectification Boost Converter).

[0107] In addition, the energy storage unit may also include a BMS (BATTERY MANAGEMENT SYSTEM).

[0108] The power conversion topology is used to realize the charging and discharging operation of the energy storage battery pack, and the BMS is used to control the charging and discharging process of the energy storage battery pack, such as controlling the power during charging and discharging.

[0109] In this embodiment, since the voltage of the coupling unit is high voltage, the power conversion topology of the energy storage unit has electrical isolation power while achieving a wide range of high and low voltage conversion, and the efficiency of the topology conversion will be low.

[0110] 2. The energy storage unit is arranged between the photovoltaic module and the power optimization unit.

[0111] Specifically, when the energy storage unit is arranged between the photovoltaic module and the power optimization unit, the specific structure is as follows: Figure 5 At this time, the photovoltaic modules are connected in parallel to the power optimization unit, and the energy storage unit is set on the low-voltage side of the photovoltaic modules.

[0112] Likewise, the energy storage unit includes a power conversion topology structure and an energy storage battery pack, wherein the power conversion topology structure is used to implement the charge and discharge operations of the energy storage battery pack.

[0113] To elaborate, the power conversion topology of the energy storage unit is the conversion between photovoltaic low voltage and battery low voltage, which does not require electrical isolation. The topology has high conversion efficiency and low material cost, and can also adjust the photovoltaic components to the maximum output power when charging the batteries in the energy storage battery pack. However, the system requires the power optimization unit to be a bidirectional conversion topology similar to CLLLC to support peak load shaving and valley filling of the power grid.

[0114] 3. The energy storage unit is arranged between the power optimization unit and the coupling unit, and is connected to the coupling unit via an electrical isolation unit.

[0115] Above Figure 3 and Figure 5 In the structure, the power electronic converter in the power optimization unit can be an isolated topology to ensure the electrical isolation of the photovoltaic module and the HEMS and the product contactable shell, and achieve safer electrical contact. Figure 6 As shown, when the energy storage unit is arranged between the power optimization unit and the coupling unit, the power optimization unit no longer has the electrical isolation function, but the electrical isolation function is implemented using a separate electrical isolation unit. At this time, the power electronic converter in the power optimization unit can adopt a non-isolated topology structure, and the electrical isolation unit adopts an isolation topology to achieve electrical isolation.

[0116] During the specific connection, the photovoltaic modules are connected in parallel to the power optimization unit, the power optimization unit and the energy storage unit are respectively connected to one end of the electrical isolation unit, and the other end of the electrical isolation unit is connected to one end of the coupling unit.

[0117] The power optimization unit can simultaneously realize MPPT (Maximum power point tracking) of the photovoltaic module and charge the energy storage battery pack. The electrical isolation unit can not only transfer solar energy to the coupling unit, but also discharge the energy storage unit to the coupling unit, and also provide electrical isolation for the system. In this case, the power conversion topology of the energy storage unit can be cancelled, that is, the energy storage unit only includes the energy storage battery pack and BMS, which can save the overall hardware cost of the system. At this time, charging and discharging can be realized by the power optimization unit and the electrical isolation unit respectively.

[0118] In addition, the energy storage unit may also include a power conversion topology and an energy storage battery pack; the power conversion topology is used to realize the charging and discharging operation of the energy storage battery pack. This structural method makes the control of the HEMS simpler.

[0119] against Figure 5 and Figure 6 The structure of the control logic is as follows Figure 7 For the specific implementation process, please refer to the above corresponding instructions.

[0120] In this embodiment, a variety of setting positions and corresponding internal structures of the energy storage unit are provided, so that a suitable setting position can be selected according to actual needs, thereby improving the selectivity of the solution and the adaptability to different scenarios.

[0121] Another embodiment of the present application provides an energy system, including the above energy control system and electrical equipment, the specific structure of which is as follows Figure 2 , 3 , 5 and 6 as shown.

[0122] Based on the structure of the above energy control system, another embodiment of the present application provides an energy control method, which is applied to the controller in the above energy control system. The energy control method may include:

[0123] Control at least two of the AC conversion unit, the power optimization unit and the energy storage unit to perform electric energy output operation.

[0124] The controller in the embodiment of the present application, specifically the specific implementation of the HEMS control program in the controller, refers to the above corresponding instructions.

[0125] In one implementation of the present application, refer to Figure 6 , controlling at least two of the AC conversion unit, the power optimization unit, and the energy storage unit to perform an electric energy output operation may include:

[0126] S11. Control the operation of the AC conversion unit so that the AC conversion unit converts the AC power output by the power grid into first electric energy.

[0127] In actual scenarios, the current water temperature of the water heater is the temperature of the water in the water heater when the heating body starts heating.

[0128] Generally, the water heater can be set to automatic heating or manual heating. In automatic heating, when the water temperature of the water heater is lower than a lower water temperature threshold (which can be set, such as 20°C), the water heater can automatically heat up. In addition, if the user manually clicks the heating button, it is considered that the heating instruction has been received, and the water heater also starts heating.

[0129] Therefore, when the current water temperature is less than a lower water temperature threshold or a heating instruction is received, the current water temperature of the water heater can be obtained.

[0130] In addition, when the water heater is heating, the user may also set a higher water temperature threshold, such as a first water temperature threshold, which is the highest temperature value. If the temperature of the water in the water heater reaches the first water temperature threshold, heating may be stopped.

[0131] Specifically, when the water heater starts to heat, the coupling unit needs to provide a fixed voltage value to the heating body. This voltage value is the DC voltage value obtained by the coupling unit from the power grid. Therefore, when the water heater starts to heat, the AC conversion unit is first controlled to start working. The AC conversion unit converts the sinusoidal voltage of the power grid into DC (i.e., the first electrical energy) and converts it into DC voltage in the coupling unit. The DC voltage is output to the heating body. After the voltage of the coupling unit is stabilized, the output waveform of the AC conversion unit is shown in FIG. Fig. 9 .

[0132] After the voltage of the coupling unit is established, the HEMS control program starts to instruct the coupling unit and the heating body to heat. At this time, the energy of the heating body all comes from the power grid, and the voltage of the coupling unit remains stable.

[0133] S12. After the voltage of the coupling unit is stabilized, control the power optimization unit to operate so that the power optimization unit converts the electric energy output by the photovoltaic assembly into second electric energy.

[0134] After the voltage of the coupling unit is stabilized, the electric energy generated by the photovoltaic module is used to provide electric energy for the water heater, because solar energy is green energy and has a low cost. At this time, the HEMS control program instructs the power optimization unit to start working, and the photovoltaic module starts to output energy to the power optimization unit. The power optimization unit converts the electric energy output by the photovoltaic module into a second electric energy and outputs it to the coupling unit.

[0135] S13. Obtain the output power of the power optimization unit.

[0136] In actual scenarios, there may be insufficient light due to environmental factors such as cloudy days, rain, snow, or there may be no light at night. In these two cases, the photovoltaic modules output less electricity, especially at night, because there is no light. At this time, the photovoltaic modules do not output electricity. If the photovoltaic modules continue to be used, the photovoltaic modules and power optimization units will need to operate, but the production capacity will be low and the utilization rate of the power optimization unit will be low.

[0137] To this end, the embodiment of the present invention can set two power thresholds, namely a first power threshold and a second power threshold. The first power threshold is less than the second power threshold. For example, the first power threshold can be a power value close to zero and slightly greater than zero, such as 10W, and the second power threshold is a larger threshold, such as 2kw.

[0138] Therefore, the output power of the power optimization unit can be obtained, and based on the comparison with the first power threshold and the second power threshold, the current operation scenario is determined, and the corresponding unit output power is selected.

[0139] S14. When the output power of the power optimization unit is less than a first threshold, control the power optimization unit to stop running, and control the energy storage unit to output a third electric energy.

[0140] Specifically, when the power output of the photovoltaic module is less than the first power threshold, it means that the current photovoltaic module has a low production capacity, which is probably a scene without light at night. At this time, in order to avoid the low utilization rate of the power optimization unit, the power optimization unit can be controlled to stop running. In addition, the energy storage unit can also be controlled to start outputting the third electric energy to avoid the problem that all the electric energy comes from the power grid, which makes the cost higher.

[0141] In one implementation, the electric energy of the energy storage unit comes from the electric energy generated by the photovoltaic assembly that is not used by electrical devices, such as water heaters, and / or the electric energy obtained from the power grid.

[0142] For example, when the water temperature in the water heater reaches the highest water temperature threshold updated in real time, that is, the first water temperature threshold, the photovoltaic module can still output a large power at this time. If the power optimization unit is turned off, it will cause a waste of solar energy of the photovoltaic module. Therefore, the HEMS of the present invention will determine whether the energy storage unit is fully charged at this time. If the energy storage unit is not fully charged, the HEMS controls the energy storage unit to start charging, and the photovoltaic module stores solar energy in the energy storage unit at maximum power until it is fully charged, and then turns off the energy storage unit and the power optimization unit, and the two units enter the standby state.

[0143] If the water temperature is determined to be lower than a smaller water temperature threshold during the process of charging the energy storage unit, the HEMS controls to stop charging the energy storage unit.

[0144] In addition, when the energy storage unit obtains electric energy from the power grid, if the electric device does not need electric energy and the current time is in the energy storage charging time period, the power grid is controlled to provide electric energy to the energy storage unit. For example, if the water heater does not need heating and the current time is in the energy storage charging time period, the power grid can be controlled to provide electric energy to the energy storage unit.

[0145] Among them, the energy storage charging time period is the time period when the electricity price is at the valley price. Generally, the electricity price may be at the valley price in the middle of the night. Therefore, when the water heater does not need to heat in the middle of the night, the AC conversion unit and the energy storage unit can be controlled to operate so that the grid electricity is transmitted to the energy storage unit.

[0146] Generally speaking, the electricity price is higher in the evening, and the water heater is used more frequently during this period. At this time, the electricity in the energy storage unit can be used to supply power, which can reduce the amount of electricity obtained from the power grid, reduce costs, and achieve peak shaving and valley filling for the power grid.

[0147] When there is electricity in the energy storage unit, the energy storage unit can be used to power the water heater. Specifically, when it is necessary to control the energy storage unit to output the third electric energy, the remaining electricity of the energy storage unit can be obtained, and when the remaining electricity is greater than the electricity threshold, and the difference between the current parameter, such as the current water temperature and the first parameter threshold, such as the first water temperature threshold, is greater than the difference threshold, the energy storage unit is controlled to output the third electric energy according to the maximum power of the energy storage unit.

[0148] Specifically, the power threshold can be a power level that allows the energy storage unit to discharge. When the remaining power of the energy storage unit is less than the power threshold, if the discharge continues, the energy storage unit will be damaged and the life of the energy storage unit will be affected. Therefore, the energy storage unit is allowed to discharge only when the remaining power is greater than the power threshold. In actual scenarios, HEMS will determine whether the power of the energy storage unit is exhausted (that is, whether it is less than the power threshold). If the energy storage unit still has power (that is, the remaining power is greater than the power threshold), HEMS controls the energy storage unit to start discharging, and the energy storage unit discharges to the coupling unit.

[0149] More specifically, in the embodiment of the present invention, since the active heating adjustment unit is provided, when the water temperature approaches the first water temperature threshold, the voltage outputted by the coupling unit to the heating body will be adjusted. Since the voltage outputted to the heating body decreases, the output power of the energy storage unit will be limited at this time. However, when the water temperature is not close to the first water temperature threshold, that is, the difference between the current water temperature and the first water temperature threshold is greater than the difference threshold, the active heating adjustment unit does not need to be used to perform voltage adjustment operation. At this time, the energy storage unit can output at the maximum power, and the maximum power is generally the rated power of the energy storage unit.

[0150] That is, when the remaining power is greater than the power threshold and the difference between the current water temperature and the first water temperature threshold is greater than the difference threshold, the energy storage unit is controlled to output the third electric energy according to the maximum power of the energy storage unit.

[0151] After controlling the energy storage unit to output the third electric energy, as the energy storage unit outputs electricity, the remaining electricity in the energy storage unit becomes smaller and smaller. If the remaining electricity of the energy storage unit is less than the electricity threshold, it is not appropriate to continue using the energy storage unit to discharge. The energy storage unit should be controlled to stop running to avoid the problem of reduced life of the energy storage unit due to excessive discharge.

[0152] S15. When the output power of the power optimization unit is greater than a first threshold and less than a second threshold, control the energy storage unit to output a third electric energy.

[0153] When the output power of the power optimization unit is greater than the first threshold and less than the second threshold, it means that the photovoltaic component generates electric energy, but the generated electric energy is average. At this time, it may be a scene with insufficient light such as cloudy, rainy, snowy, etc. At this time, the photovoltaic capacity can continue to be used. Since the photovoltaic capacity is average, the energy storage unit can be controlled to output the third electric energy to reduce the electric energy obtained from the power grid and reduce costs.

[0154] In addition, when the output power of the power optimization unit is greater than the second threshold, it indicates that the photovoltaic module has a high production capacity, and the power supply demand of the water heater may be met by using only the photovoltaic module, or a small amount of grid power may be used to meet the power supply demand of the water heater. Therefore, at this time, only the power generated by the photovoltaic module and the grid power supply are used, and there is no need to use the energy storage unit for power supply.

[0155] In addition, when the output power of the power optimization unit is greater than the second threshold, it means that the photovoltaic module has a high production capacity, and the power supply demand of the water heater may be met by using only the photovoltaic module, or a small amount of energy storage unit power may be used to meet the power supply demand of the water heater. Therefore, at this time, only the power generated by the photovoltaic module and the energy storage unit can be used for power supply, and there is no need to use the power of the grid for power supply.

[0156] S16. Adjust the operating state of at least one unit that outputs electric energy among the AC conversion unit, the power optimization unit and the energy storage unit.

[0157] In the embodiment of the present invention, when the units outputting electric energy in the AC conversion unit, the power optimization unit and the energy storage unit are different, the process of adjusting the operating state of the units outputting electric energy is also different, which are now introduced separately.

[0158] 1. Only the AC conversion unit and the power optimization unit output electrical energy.

[0159] In actual scenarios, when the water heater needs to be heated, the HEMS instructs the AC conversion unit to start working. The AC conversion unit converts the sinusoidal voltage of the grid into DC and converts it into DC voltage in the coupling unit. After the voltage of the coupling unit is stabilized, the output waveform of the AC conversion unit is shown in Figure 1. Fig. 9 After the voltage of the coupling unit is established, the HEMS starts to instruct the coupling unit and the heating body to heat. At this time, the energy of the heating body comes entirely from the power grid, and the voltage of the coupling unit remains stable.

[0160] Then the HEMS instructs the power optimization unit to start working, and the photovoltaic module starts to output energy to the coupling unit, causing the voltage of the coupling unit to rise. When the photovoltaic module starts to generate electricity, it does not reach the maximum power point, and the power generation energy is not optimal at this time. In order to optimize the power generation capacity of the photovoltaic module, the photovoltaic module will be controlled to reach the maximum power point in the embodiment of the present application.

[0161] The HEMS control program will adjust the operating state of the power optimization unit to adjust the power of the photovoltaic module. In addition, in order to ensure the voltage stability of the coupling unit, the output power of the AC conversion unit will also be adjusted.

[0162] In one implementation, when adjusting the operating state of the power optimization unit, it may be:

[0163] The operating parameters of the electrical equipment during operation, such as the operating parameters of the water heater during heating, are obtained, and the operating power of the power optimization unit is adjusted according to the operating parameters until the power of the photovoltaic module reaches the maximum power point (MPP).

[0164] Among them, the operating parameters of the electrical equipment during operation, such as the operating parameters of the water heater during heating, can be as follows:

[0165] Data such as voltage and current of photovoltaic modules.

[0166] After the above operating parameters are collected through the communication architecture, the above data can be used to adopt a preset algorithm to intelligently determine the optimal power output of the power optimization unit and perform power control on the power optimization unit until the power of the photovoltaic module reaches the maximum power point.

[0167] In the process of continuously adjusting the operating state of the power optimization unit, the power optimization unit converts the electric energy output by the photovoltaic module into the second electric energy. The voltage of the second electric energy output by the power optimization unit will change, generally gradually increasing. At this time, outputting the second electric energy to the coupling unit will cause the voltage of the coupling unit to rise and cannot be stabilized at a fixed value. At this time, it is necessary to control the AC conversion unit so that the voltage of the coupling unit is stabilized at a fixed value.

[0168] In actual scenarios, if the AC conversion unit is a non-controllable conversion unit, its output energy will automatically decrease due to the increase in the coupling unit voltage, so that the coupling unit voltage remains stable. The current flowing through the AC conversion unit changes before and after. Figure 8 .

[0169] If the AC conversion unit is a controllable industrial frequency rectifier conversion circuit, the change trend of its output energy is consistent with the change trend of the uncontrollable conversion unit. If the AC conversion unit is a controllable high-frequency chopper conversion circuit, the AC conversion unit can be controlled by HEMS to actively reduce the output energy to keep the coupling unit voltage stable.

[0170] Then in an implementation of the present application, after adjusting the operating power of the power optimization unit according to the operating parameter, the method further includes:

[0171] According to the voltage value of the second electric energy output by the power optimization unit, the current value of the first electric energy output by the AC conversion unit is adjusted so that the voltage of the coupling unit is a fixed value.

[0172] Specifically, since the fixed voltage value of the coupling unit when it is stable is known, the voltage value of the second electric energy output by the power optimization unit can be obtained through communication collection. Since the voltage value of the coupling unit is determined by the voltage value of the first electric energy and the voltage value of the second electric energy, the fixed voltage value of the coupling unit and the actual voltage value of the second electric energy are directly used to obtain the theoretical voltage value of the first electric energy, and then the theoretical voltage value of the first electric energy is used to adjust the current value of the first electric energy output by the AC conversion unit, so that the voltage of the coupling unit is stabilized at a fixed value, and then the voltage output by the coupling unit to the heating body is stabilized, thereby improving the reliability of heating of the heating body.

[0173] As the energy output by the photovoltaic module increases, the power optimization unit outputs more and more energy to the coupling unit. Since the voltage of the coupling unit is fixed, the energy given to the coupling unit by the AC conversion unit becomes less and less, until the photovoltaic module reaches the maximum power point, the energy output by the power optimization unit is fixed, and the energy output by the AC conversion unit no longer changes. During this process, the voltage of the coupling unit is always maintained in a dynamic balance. At this time, the photovoltaic module is fully utilized and the electricity obtained from the power grid is the least, further increasing the proportion of green electricity used in the system. In some cases, HEMS is used to adjust and only the energy emitted by the photovoltaic module is used to provide electricity for the heating body.

[0174] In this embodiment, the adaptability of the coupling unit ensures that the heating body uses the energy of photovoltaic power generation as much as possible, thereby increasing the proportion of green electricity used in the system and making the system more low-carbon and environmentally friendly. In addition, the HEMS control function makes the energy allocation of the energy control system more intelligent and efficient, saving users more electricity costs and bringing users more convenient interaction and experience.

[0175] On the basis of the above embodiment, as the heating body is continuously heated, the temperature of the water in the water heater becomes higher and higher, gradually approaching the first water temperature threshold set by the user. At this time, in order to make the water temperature gradually approach the first water temperature threshold and not exceed the first water temperature threshold, in an implementation of the present application, after controlling the AC conversion unit to convert the AC power output by the power grid into the first electric energy, and controlling the power optimization unit to convert the electric energy output by the photovoltaic module into the second electric energy, it also includes:

[0176] The active heating adjustment unit is controlled to adjust the voltage value outputted from the coupling unit to the water heater, so as to realize the stepless heating adjustment of the heating body. The specific implementation process refers to the corresponding description above.

[0177] It should be noted that when the heating active adjustment unit is not used, the current of the first electric energy output by the AC conversion unit is adjusted in accordance with the above-mentioned method of "using the fixed voltage value of the coupling unit and the actual voltage value of the second electric energy to obtain the theoretical voltage value of the first electric energy, and then using the theoretical voltage value of the first electric energy to adjust the current value of the first electric energy output by the AC conversion unit". When the heating active adjustment unit is used to control the voltage of the heating body, the theoretical voltage value of the first electric energy output by the AC conversion unit can be calculated using the grid voltage, the output current of the power optimization unit, the output current of the AC conversion unit, the voltage of the coupling unit, the voltage at both ends of the heating body, the current flowing through the heating body, the temperature of the heating body, the water temperature, the water volume and other data, and the current of the first electric energy output by the AC conversion unit can be adjusted according to the theoretical voltage value.

[0178] In this embodiment, the active heating adjustment unit can realize the intelligence of the heating process and achieve stepless adjustment of the heating through built-in logic and algorithms.

[0179] In another implementation of the present application, as the heating body is continuously heated, the temperature of the water in the water heater reaches a first water temperature threshold set by the user. At this time, the AC conversion unit and the power optimization unit can be controlled to stop running and enter a standby state to save resources.

[0180] Specifically, when the water temperature reaches the first water temperature threshold that is updated in real time, the photovoltaic module can still output a large power. If the power optimization unit is turned off, it will cause a waste of solar energy of the photovoltaic module. Therefore, the HEMS control program of the present invention will determine whether the energy storage unit is fully charged at this time. If the energy storage unit is not fully charged, the HEMS control program controls the energy storage unit to start charging, and the photovoltaic module stores solar energy in the energy storage unit at maximum power until it is fully charged and then turns off each unit and enters standby mode. If the water temperature is judged to be lower than the set value during the process of charging the energy storage unit, the HEMS control program controls to stop charging the energy storage unit, and the HEMS control program re-acquires the set temperature and re-heats the heating body according to the above process. For its specific implementation, please refer to Fig.11 shown.

[0181] In this embodiment, the output power of the photovoltaic module is actively optimized to ensure that the photovoltaic module works at the maximum power point, which greatly improves the utilization rate of the photovoltaic module. In addition, the adaptability of the coupling unit ensures that the heating body uses the energy of photovoltaic power generation as much as possible, which increases the proportion of green electricity used in the system and makes the system more low-carbon and environmentally friendly.

[0182] 2. Only the AC conversion unit and the energy storage unit output electrical energy.

[0183] At night, the HEMS control program obtains the set water temperature and then instructs the AC conversion unit to start working. The AC conversion unit converts the sinusoidal voltage of the grid into DC and converts it into DC voltage in the coupling unit. After the voltage of the coupling unit is stabilized, the output waveform of the AC conversion unit is shown in Figure 1. Fig. 9 After the voltage of the coupling unit is established, the HEMS starts to instruct the coupling unit and the heating body to heat. At this time, the energy of the heating body comes entirely from the power grid, and the voltage of the coupling unit remains stable.

[0184] Since there is no light at night, the output power of the power optimization unit is less than the first threshold value, and the power optimization unit is controlled to stop running. In addition, the HEMS control program will determine whether the power of the energy storage unit is exhausted. If the energy storage unit still has power, the HEMS controls the energy storage unit to start discharging. As the energy storage unit discharges to the coupling unit, the voltage of the coupling unit rises. If the AC conversion unit is a non-controllable conversion unit, the energy it outputs will be reduced due to the increase in the voltage of the coupling unit, so that the voltage of the coupling unit remains stable until the energy storage unit outputs at maximum power. At this time, the energy output from the AC conversion unit to the coupling unit reaches a minimum or even 0, and then maintains this stable state to continue heating the heating body until the water temperature reaches the latest set temperature obtained. If the HEMS determines that the energy storage unit is exhausted during the heating process of this energy storage unit, the HEMS controls to shut down the energy storage unit, the output energy of the AC conversion unit increases, and the energy of the heating body comes entirely from the power grid until the water temperature reaches the latest set temperature obtained.

[0185] If the AC conversion unit is a controllable high-frequency chopper conversion circuit, the HEMS can be used to control the AC conversion unit to actively reduce the output energy to keep the coupling unit voltage stable.

[0186] When the water temperature reaches the latest temperature, the energy storage unit and AC conversion unit are turned off and enter standby mode. When the water temperature drops to a certain difference from the set temperature, the system restarts heating according to the above process. Fig.11 .

[0187] 3. Only the power optimization unit and the energy storage unit output electrical energy.

[0188] HEMS obtains the water temperature and then instructs the AC conversion unit to start working. The AC conversion unit converts the sinusoidal voltage of the power grid into DC and converts it into DC voltage in the coupling unit. After the voltage of the coupling unit is established, HEMS starts to instruct the coupling unit and the heating body to heat. At this time, the energy of the heating body comes entirely from the power grid, and the voltage of the coupling unit remains stable. Then HEMS instructs the power optimization unit to start working, and the photovoltaic module begins to output energy to the coupling unit, causing the voltage of the coupling unit to rise. During the charging process, as the energy output of the photovoltaic module increases, the energy given to the coupling unit by the AC conversion unit decreases, until the photovoltaic module reaches the maximum power point and the energy output by the AC converter no longer changes. At this time, the HEMS control program will determine whether the energy storage unit is exhausted. If the energy storage unit still has power and the remaining power is greater than the power output of the power grid, the energy storage unit can be introduced to control the power output of the energy storage unit to be the same as the power of the power grid, so as to achieve voltage stability of the coupling unit.

[0189] The subsequent implementation process refers to the above corresponding instructions.

[0190] 4. The AC conversion unit, the power optimization unit and the energy storage unit all output electrical energy.

[0191] When the sunlight is insufficient during the day, HEMS obtains the water temperature and then instructs the AC conversion unit to start working. The AC conversion unit converts the sinusoidal voltage of the power grid into DC and converts it into DC voltage in the coupling unit. After the voltage of the coupling unit is established, HEMS starts to instruct the coupling unit and the heating body to heat. At this time, the energy of the heating body comes entirely from the power grid, and the voltage of the coupling unit remains stable. Then HEMS instructs the power optimization unit to start working, and the photovoltaic module starts to output energy to the coupling unit, causing the voltage of the coupling unit to rise. During the charging process, as the energy output of the photovoltaic module increases, the energy given to the coupling unit by the AC conversion unit decreases, until the photovoltaic module reaches the maximum power point, the energy output by the AC converter no longer changes. At this time, the HEMS control program will determine whether the power of the energy storage unit is exhausted. If the energy storage unit still has power and the remaining power is less than the power output of the power grid, the energy storage unit can be introduced to adjust the output power of the energy storage unit to the set power, that is, the energy storage unit is controlled to output electrical energy according to the set power. The insufficient sum of the power output of the photovoltaic module and the energy storage unit is supplemented by the power grid to achieve voltage stability of the coupling unit.

[0192] There are multiple ways to set the power, which are introduced below.

[0193] 1. The set power is the maximum output power of the energy storage unit, that is, the energy storage unit output is maximum at this time.

[0194] 2. Set the power to make the grid output power reach the specified value.

[0195] Specifically, the designated value is zero or a value close to zero, so that the power grid outputs the least amount of electric energy. If the designated value is zero, it is the above-mentioned situation of "only the power optimization unit and the energy storage unit output electric energy".

[0196] 3. The set power is the difference between the rated output power of the power optimization unit and the actual power generated by the photovoltaic module.

[0197] like Figure 5 As shown, when the energy storage unit is arranged between the photovoltaic module and the power optimization unit, the power output of the power optimization unit cannot exceed its own maximum power limit because the power optimization unit has its own maximum power limit, wherein its own maximum power refers to the rated output power. Therefore, the sum of the power output of the energy storage unit and the power output of the photovoltaic module should not exceed the rated output power of the power optimization unit. Therefore, the power of the energy storage unit at this time is the difference between the rated output power of the power optimization unit and the actual power generated by the photovoltaic module.

[0198] 4. The set power is the difference between the rated output power of the electrical isolation unit and the actual output power of the power optimization unit.

[0199] like Figure 6 As shown, the energy storage unit is arranged between the power optimization unit and the coupling unit, and is connected to the coupling unit via an electrical isolation unit.

[0200] Since the electrical isolation unit has its own maximum power limit, its output power cannot exceed its own maximum power (rated output power) limit. Therefore, the sum of the power output by the energy storage unit and the power output by the power optimization unit should not exceed the maximum power (rated output power) limit of the electrical isolation unit itself. Therefore, the power of the energy storage unit at this time is the difference between the rated output power of the electrical isolation unit and the actual output power of the power optimization unit.

[0201] In this embodiment, when there is light during the day but the light is insufficient, the power optimization unit, the energy storage unit and the AC conversion unit are controlled to heat the heating body at the same time. It can even be decided whether to use the energy storage unit for heating or the grid AC for heating by comprehensively considering the electricity cost and the peak-to-valley difference. The relevant algorithms can be integrated in the HEMS.

[0202] As can be seen from the above, the embodiment of the present invention has several parts, including a power optimization unit, an energy storage unit, an AC conversion unit, and a heating active adjustment unit. The power optimization unit, the energy storage unit, and the AC conversion unit can all be used as input ports of the system, and the energy storage unit and the AC conversion unit can be used as output ports of the system energy. The system has the characteristics of multiple inputs and multiple outputs. Therefore, by centralizing the adaptive algorithm in the HEMS, the autonomous adjustment of each port can be realized, the autonomous optimal allocation of energy can be realized, and the user's use efficiency can be maximized.

[0203] In this embodiment, compared with the existing photovoltaic heating water heater, a thermal energy management system (HEMS) is introduced, and a power conversion unit with complete isolation of the DC side and the AC side and flexible AC-DC coupling is established, and the maximum power tracking of the photovoltaic panel power generation can be achieved, so that the output power of the photovoltaic module is maintained at the maximum power point. By introducing an energy storage unit, the solar energy converted by the photovoltaic module is stored in the energy storage unit when heating is not required, so as to store the multiple solar green electricity. When there is no light and the photovoltaic module cannot generate electricity, the electric energy of the energy storage unit is released for heating the water heater, so as to ensure that the amount of electricity obtained from the power grid is minimized, provide users with the best economic efficiency, and greatly improve the utilization rate of the photovoltaic module. At the same time, the photovoltaic panels do not need to be connected in series, which is more suitable for home application scenarios. The optimal power output is intelligently judged based on data such as water temperature, heating body voltage and current, and the amount of electricity in the energy storage unit, so as to achieve better economic benefits. In addition, the present invention realizes the isolation between the grid side and the photovoltaic side through topological electrical isolation, improves the safety of the water heater, and reduces the risk of electric shock of the equipment.

[0204] In addition, the heating active adjustment unit can realize the intelligentization of the heating process, and the built-in logic and algorithm can realize stepless adjustment of the heating. At the same time, by adjusting the voltage of the coupling unit, it is ensured that the heating energy comes from the photovoltaic components as much as possible, saving the user's electricity consumption as much as possible and realizing efficient green electricity use.

[0205] In addition, the built-in algorithm can be used to smooth out the peaks and fill the valleys of electricity prices, reasonably balance the use of solar energy and grid energy, and provide users with the most economical energy consumption.

[0206] In addition, due to the HEMS, the system's energy allocation is more intelligent and efficient, saving users more electricity costs and bringing users more convenient interaction and experience.

[0207] On the basis of the above-mentioned embodiment, another embodiment of the present application provides an energy conversion device, such as the above-mentioned controller, which is used to execute the above-mentioned energy control method.

[0208] Also provided in an embodiment of the present application is a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an energy conversion device, the energy conversion device implements any one of the energy control methods provided in the embodiments of the present application.

[0209] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an energy conversion device, the energy conversion device can implement any energy control method provided in the embodiment of the present application.

[0210] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An energy control system, characterized in that: include: An AC conversion unit, a power optimization unit, an energy storage unit, a coupling unit and a controller; the AC conversion unit and the power optimization unit are directly connected to the coupling unit respectively, the energy storage unit is directly or indirectly connected to the coupling unit, and the controller is communicatively connected to the AC conversion unit, the power optimization unit, the coupling unit and the energy storage unit respectively; The controller is used to control at least two units among the AC conversion unit, the power optimization unit and the energy storage unit to perform electric energy output operation; The AC conversion unit is used to convert the AC power output by the power grid into the first electric energy based on the control instruction of the controller; The power optimization unit is used to convert the electric energy output by the photovoltaic assembly into second electric energy based on the control instruction of the controller; The energy storage unit is used to output the third electric energy based on the control instruction of the controller; The electric energy stored in the energy storage unit includes: the electric energy generated by the photovoltaic assembly but not used by the electric equipment, and / or the electric energy obtained from the power grid; The coupling unit is used to couple the electric energy output by the at least two units to obtain and output the total electric energy to the electric device.

2. The energy control system according to claim 1, characterized in that: The energy storage unit is arranged between the photovoltaic assembly and the power optimization unit.

3. The energy control system according to claim 2, characterized in that: In the case where the energy storage unit is directly connected to the coupling unit, or the energy storage unit is arranged between the photovoltaic assembly and the power optimization unit, the energy storage unit includes a power conversion topology and an energy storage battery pack; The power conversion topology is used to implement the charging and discharging operations of the energy storage battery pack.

4. The energy control system according to claim 1, characterized in that: The energy storage unit is arranged between the power optimization unit and the coupling unit, and is connected to the coupling unit via an electrical isolation unit.

5. The energy control system according to claim 4, characterized in that: The energy storage unit includes an energy storage battery pack; Alternatively, the energy storage unit includes both a power conversion topology structure and an energy storage battery pack; the power conversion topology structure is used to implement charging and discharging operations of the energy storage battery pack.

6. The energy control system according to claim 1, characterized in that: The energy control system further comprises: An active heating regulating unit located between the coupling unit and the electrical device; The active heating regulation unit is used to regulate the voltage value outputted from the coupling unit to the electrical device, so as to achieve stepless heating regulation of the electrical device.

7. An energy system, characterized in that: It comprises an energy control system and electrical equipment as described in any one of claims 1 to 6.

8. An energy control method, characterized in that: A controller applied to an energy control system according to any one of claims 1 to 6, wherein the energy control method comprises: Control at least two of the AC conversion unit, the power optimization unit and the energy storage unit to perform electric energy output operation.

9. The energy control method according to claim 8, characterized in that: Controlling at least two of the AC conversion unit, the power optimization unit, and the energy storage unit to perform an electric energy output operation, comprising: Controlling the AC conversion unit to operate so that the AC conversion unit converts the AC power output by the power grid into the first electric energy; After the voltage of the coupling unit is stabilized, controlling the power optimization unit to operate so that the power optimization unit converts the electric energy output by the photovoltaic assembly into the second electric energy; Obtaining the output power of the power optimization unit; When the output power of the power optimization unit is less than a first threshold, controlling the power optimization unit to stop running, and controlling the energy storage unit to output a third electric energy; When the output power of the power optimization unit is greater than the first threshold and less than the second threshold, controlling the energy storage unit to output a third electric energy; Adjust the operating state of at least one unit that outputs electric energy among the AC conversion unit, the power optimization unit and the energy storage unit.

10. The energy control method according to claim 9, characterized in that: Controlling the energy storage unit to output a third electric energy comprises: Obtaining the remaining power of the energy storage unit; When the remaining power is greater than the power threshold and the difference between the current parameter and the first parameter threshold is greater than the difference threshold, the energy storage unit is controlled to output the third electric energy according to the maximum power of the energy storage unit.

11. The energy control method according to claim 9, characterized in that: After controlling the energy storage unit to output the third electric energy, the method further includes: If the remaining power of the energy storage unit is less than the power threshold, the energy storage unit is controlled to stop running.

12. The energy control method according to claim 9, characterized in that: Adjusting the operating state of at least one unit outputting electric energy among the AC conversion unit, the power optimization unit, and the energy storage unit comprises: If only the AC conversion unit and the power optimization unit output electric energy, obtain the operating parameters of the electric equipment during operation, and adjust the operating power of the power optimization unit according to the operating parameters until the power of the photovoltaic module reaches the maximum power point; If the AC conversion unit, the power optimization unit and the energy storage unit all output electrical energy, the output power of the energy storage unit is adjusted to a set power.

13. The energy control method according to claim 12, characterized in that: The set power is the maximum output power of the energy storage unit, the power that makes the grid output power a specified value, the difference between the rated output power of the power optimization unit and the actual power generated by the photovoltaic component, or the difference between the rated output power of the electrical isolation unit and the actual output power of the power optimization unit.

14. The energy control method according to claim 8, characterized in that: Also includes: When the electric device does not need electric energy and the current time is in the energy storage charging time period, the power grid is controlled to provide electric energy to the energy storage unit.

15. An energy conversion device, characterized in that: Used to execute the energy control method as claimed in any one of claims 8 to 14.

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