Energy storage air conditioning system and control method and control device thereof

Abstract

The present invention discloses an energy storage air conditioning system and a control method and control device thereof. The energy storage air conditioning system includes: a compressor, a first converter, an energy storage battery and a second converter; the energy storage battery and the second converter are located inside the air conditioning outdoor unit, and the energy storage battery is connected to the power grid through the second converter; the compressor is connected to the power grid through the first converter; the energy storage battery is used to charge and discharge according to the current power distribution control strategy of the energy storage air conditioning system, wherein the energy storage battery is discharged to power the air conditioner. The present invention integrates energy storage into the air conditioner to achieve an integrated design of energy storage and air conditioning, reduce floor space, and does not need to set up heat dissipation for the energy storage battery separately, and can be cooled by means of the heat dissipation design of the air conditioner outdoor unit itself. With the energy storage battery, the charging and discharging of the energy storage battery and the air conditioning can be controlled according to the power distribution control strategy, and only interfaces with lower rated power than the air conditioner are opened for external applications, thereby reducing the power distribution capacity of the air conditioner and the current carrying capacity of the cable, and reducing the power consumption of the air conditioner.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an energy storage air conditioning system and a control method and a control device thereof. Background Art

[0002] As a load with a high proportion of energy consumption, air conditioners also account for a high proportion of power distribution capacity and electricity consumption. Air conditioners are generally operated during peak electricity price periods, when air conditioners use the most power, resulting in high electricity consumption and poor economic efficiency.

[0003] At the beginning of the operation of variable frequency air conditioners, they will run at high frequency and use high power to ensure rapid cooling / heating of the air conditioner and ensure user comfort. However, this operation process causes a sudden increase in the power consumption of the air conditioner, and when the demand is met, the power is quickly reduced to save energy, resulting in drastic changes in power consumption, causing large fluctuations in source-load flow, large air conditioner distribution capacity and cable current carrying capacity. The power consumption of fixed frequency air conditioners is relatively constant, but the compressor needs to be frequently turned on or off to adjust the indoor temperature, resulting in unstable power consumption.

[0004] For photovoltaic air conditioners, under the DC system, photovoltaics are generally used as part of the new energy power generation side for overall use within the system, rather than a "point-to-point" internal connection between photovoltaics and air conditioners. Therefore, when photovoltaic power generation is greater than air conditioning power consumption, photovoltaics will not be connected to the AC grid, but will directly drive other DC loads or energy storage for charging and standby. It also cannot solve the problem of large air conditioning distribution capacity.

[0005] With regard to the problems of large power distribution capacity and high power consumption of air conditioners in the prior art, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiment of the present invention provides an energy storage air conditioning system and a control method and a control device thereof, so as to solve the problem of large power distribution capacity and high power consumption of air conditioners in the prior art.

[0007] To solve the above technical problems, an embodiment of the present invention provides an energy storage air conditioning system, comprising: a compressor, a first converter, an energy storage battery and a second converter;

[0008] The energy storage battery and the second converter are located inside the air conditioner outdoor unit, and the energy storage battery is connected to the power grid through the second converter;

[0009] The compressor is connected to the grid via the first converter;

[0010] The energy storage battery is used to charge and discharge according to the current power distribution control strategy of the energy storage air conditioning system, wherein the energy storage battery is discharged to power the air conditioner.

[0011] Optionally, the energy storage air conditioning system further includes: a switch, one end of the switch being connected to the output end of the second inverter, and the other end being connected to the energy storage battery, and the switch being used to stop charging and discharging the energy storage battery when disconnected.

[0012] Optionally, the energy storage air conditioning system further includes: a soft start circuit, wherein the input end of the soft start circuit is connected to the power grid, and the output end of the soft start circuit is connected to the input end of the first converter and the input end of the second converter.

[0013] Optionally, the energy storage air-conditioning system also includes: a main controller, connected to the energy storage battery, the input end of the first inverter and the input end of the second inverter, for determining a current power distribution control strategy of the energy storage air-conditioning system, and under the current power distribution control strategy, controlling the charging and discharging of the energy storage battery and the operation of the air conditioner according to the charge state of the energy storage battery in the energy storage air-conditioning system, the power consumption of the air conditioner and the current power consumption time period.

[0014] Optionally, the energy storage air conditioning system also includes: a battery management system connected to the energy storage battery, used to monitor the status of the energy storage battery and provide protection for the energy storage battery; the battery management system, the first inverter and the second inverter have no main communication connection.

[0015] Optionally, the energy storage air conditioning system also includes: an auxiliary power supply, which is respectively connected to the power grid, the first inverter, the second inverter and the battery management system, and is used to draw power from the power grid to power the first inverter, the second inverter and the battery management system.

[0016] Optionally, if the power grid is a DC microgrid, the first converter is DC / AC and the second converter is DC / DC; if the power grid is an AC microgrid, the first converter is AC / AC and the second converter is AC / DC; if the power grid is an AC / DC hybrid microgrid, the first converter is DC / AC or AC / AC, and the second converter is DC / DC or AC / DC.

[0017] The embodiment of the present invention further provides a control method for an energy storage air conditioning system, which is applied to the above energy storage air conditioning system, and the method includes:

[0018] Determining a current power distribution control strategy of the energy storage air conditioning system;

[0019] Under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period.

[0020] Optionally, under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, including:

[0021] If the current power distribution control strategy is an energy storage economic operation strategy, determining whether the state of charge of the energy storage battery meets the discharge requirements;

[0022] If the discharge requirement is met, determining whether the power consumption of the air conditioner is greater than a power distribution power threshold;

[0023] If it is greater than the distribution power threshold, the charging and discharging of the energy storage battery is controlled according to the current power consumption time period.

[0024] Optionally, controlling the charging and discharging of the energy storage battery according to the current power consumption time period includes:

[0025] If the current power consumption time period is a peak period, controlling the energy storage battery to discharge to supply the air conditioner;

[0026] If the current power consumption time period is a valley period, charging the energy storage battery through the power grid;

[0027] If the current power consumption time period is a normal period, the energy storage battery is controlled to neither be charged nor discharged.

[0028] Optionally, the method further includes: if the power consumption of the air conditioner is not greater than the power distribution power threshold, controlling the energy storage battery to neither charge nor discharge.

[0029] Optionally, the method further includes:

[0030] If the state of charge of the energy storage battery does not meet the discharge requirement, determining the current state of the energy storage battery according to the state of charge of the energy storage battery;

[0031] If the energy storage battery is in an overcharge state or at the calibration time, the energy storage battery is controlled to be neither charged nor discharged, and the process returns to the step of determining whether the state of charge of the energy storage battery meets the discharge requirement;

[0032] If the energy storage battery is in an over-discharge state, the energy storage battery is forcibly charged until the state of charge requirement is met, and the step of returning to determine whether the state of charge of the energy storage battery meets the discharge requirement is performed;

[0033] If the energy storage batteries are not in an overcharge state, calibration time, or over-discharge state, a fault alarm is output.

[0034] Optionally, under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, including:

[0035] If the current power distribution control strategy is a power-limited operation strategy, determining whether the power consumption of the air conditioner is greater than a power distribution power threshold;

[0036] If it is greater than the power distribution power threshold, determining whether the state of charge of the energy storage battery meets the discharge requirement;

[0037] If the discharge requirement is met, the energy storage battery is controlled to discharge to supply the air conditioner.

[0038] Optionally, the method further includes: if the charge state of the energy storage battery does not meet the discharge requirement, reducing the power consumption of the air conditioner so that the power consumption is less than or equal to the distribution power threshold.

[0039] Optionally, the method further includes:

[0040] If the power consumption of the air conditioner is not greater than the power distribution power threshold, determining whether the state of charge of the energy storage battery is fully charged;

[0041] If it is not in full power state, determine whether the current power consumption period is a valley period;

[0042] If it is a valley period, the energy storage battery is charged through the power grid until the state of charge of the energy storage battery meets the state of charge requirement, and the process returns to the step of determining whether the power consumption of the air conditioner is greater than the power distribution power threshold;

[0043] If it is not a valley period, then wait for the valley period to charge the energy storage battery.

[0044] Optionally, the method also includes: if the charge state of the energy storage battery is fully charged, then on the premise of not exceeding the distribution power threshold, increasing the power consumption of the air conditioner, and returning to the step of determining whether the power consumption of the air conditioner is greater than the distribution power threshold.

[0045] Optionally, under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, including:

[0046] If the current power distribution control strategy is a constant power operation strategy, the power consumption of the air conditioner is controlled to be constant at a preset power, and it is determined whether the power consumption of the air conditioner is greater than a power distribution power threshold;

[0047] If it is greater than the power distribution power threshold, determining whether the state of charge of the energy storage battery meets the discharge requirement;

[0048] If the discharge requirement is met, controlling the energy storage battery to discharge to supply the air conditioner;

[0049] If it is not greater than the distribution power threshold, determine whether the charge state of the energy storage battery is fully charged. If it is fully charged, control the energy storage battery to neither charge nor discharge. If it is not fully charged, control the energy storage battery to charge during the valley period.

[0050] The embodiment of the present invention further provides a control device for an energy storage air conditioning system, comprising:

[0051] A determination module, used to determine the current power distribution control strategy of the energy storage air conditioning system;

[0052] The control module is used to control the charging and discharging of the energy storage battery and the operation of the air conditioner under the current power distribution control strategy according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period.

[0053] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the control method of the energy storage air conditioning system as described in the embodiment of the present invention is implemented.

[0054] By applying the technical solution of the present invention, energy storage is integrated into the air conditioner to realize the integrated design of energy storage and air conditioning, which reduces the space occupied. In addition, such an integrated design does not require a separate heat dissipation for the energy storage battery, and heat can be dissipated by means of the heat dissipation design of the air conditioner outdoor unit itself. By using the energy storage battery, the charging and discharging of the energy storage battery and the air conditioner can be controlled according to the power distribution control strategy. Only interfaces with lower rated power than the air conditioner are opened to external applications, which reduces the power distribution capacity of the air conditioner and the current carrying capacity of the cable, reduces the power consumption of the air conditioner, and tries to ensure the economy of the power consumption of the air conditioner, and includes the power consumption of the energy storage air conditioning system into low-consumption products. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a structural schematic diagram of an energy storage air conditioning system provided in Embodiment 1 of the present invention;

[0056] Figure 2 is a schematic diagram of the specific structure of the energy storage air conditioning system under the DC microgrid provided in the first embodiment of the present invention;

[0057] Figure 3 is a flow chart of a control method for an energy storage air conditioning system provided in Embodiment 2 of the present invention;

[0058] Figure 4is a flow chart of a control method of an energy storage air conditioning system under an energy storage economic operation strategy provided in Embodiment 2 of the present invention;

[0059] Figure 5 is a flow chart of a control method of an energy storage air conditioning system under a power-limited operation strategy provided in Embodiment 2 of the present invention;

[0060] Figure 6 is a flow chart of a control method of an energy storage air conditioning system under a constant power operation strategy provided by Embodiment 2 of the present invention;

[0061] Figure 7 It is a structural block diagram of the control device of the energy storage air conditioning system provided in the third embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] Embodiment 1

[0064] This embodiment provides an energy storage air conditioning system that integrates energy storage and air conditioning, and can be applied to a DC microgrid, an AC microgrid, and an AC / DC hybrid microgrid.

[0065] Figure 1 is a schematic diagram of the structure of the energy storage air conditioning system provided in the first embodiment of the present invention. Figure 1 As shown, the energy storage air conditioning system includes: a compressor 11, a first inverter 12, an energy storage battery 13 and a second inverter 14.

[0066] The energy storage battery 13 and the second converter 14 are located inside the air conditioner outdoor unit, and the energy storage battery 13 is connected to the power grid 15 via the second converter 14;

[0067] The compressor 11 is connected to the power grid 15 via a first converter 12;

[0068] The energy storage battery 13 is used to charge and discharge according to the current power distribution control strategy of the energy storage air conditioning system, wherein the energy storage battery is discharged to power the air conditioner.

[0069] This embodiment integrates energy storage into the air conditioner to achieve an integrated design of energy storage and air conditioning, reducing floor space. In addition, such an integrated design does not require a separate heat dissipation for the energy storage battery, and can be used to dissipate heat with the help of the heat dissipation design of the air conditioner's outdoor unit, such as a heat dissipation fan on the air source outdoor unit, a waterway system on the water source outdoor unit, etc. By using energy storage batteries, the charging and discharging of the energy storage batteries and the air conditioner can be controlled according to the power distribution control strategy. Only interfaces with lower rated power than the air conditioner are opened to external applications, reducing the air conditioner's power distribution capacity and cable current carrying capacity, reducing the air conditioner's power consumption, and ensuring the economy of air conditioning electricity use as much as possible, and including the power consumption of the energy storage air conditioning system in low-consumption products.

[0070] According to the difference of the power grid, the first converter and the second converter are also different to achieve the purpose of correct conversion. Specifically, if the power grid is a DC microgrid, the first converter 12 is DC / AC, and the second converter 14 is DC / DC; if the power grid is an AC microgrid, the first converter 12 is AC / AC, and the second converter 14 is AC / DC; if the power grid is an AC / DC hybrid microgrid, the first converter 12 is DC / AC or AC / AC, and the second converter 14 is DC / DC or AC / DC.

[0071] Reference below Figure 2 The structure of the energy storage air conditioning system is described in detail. Figure 2 Taking a DC microgrid as an example, the two wires drawn from the grid 15 are respectively the positive pole and the negative pole. The first converter 12 is a DC / AC converter, and the second converter 14 is a DC / DC converter.

[0072] The energy storage air conditioning system may further include: a switch 16, one end of the switch 16 is connected to the output end of the second converter 14, and the other end is connected to the energy storage battery 13, and the switch 16 is used to stop the charging and discharging of the energy storage battery 13 when disconnected. The switch 16 can cut off the connection between the energy storage battery 13 and the second converter 14, so as to stop or start the charging and discharging of the battery.

[0073] The energy storage air conditioning system may further include: a soft start circuit 17, the input end of the soft start circuit 17 is connected to the power grid 15, and the output end is connected to the input end of the first converter 12 and the input end of the second converter 14. The soft start circuit 17 is located at the front end of the energy storage battery and the air conditioner, and can ensure that the capacitor in the energy storage air conditioning system has no short-circuit current impact to the outside when starting. The embodiment of the present invention does not limit the specific structure of the soft start circuit, as long as soft start can be achieved and short-circuit current impact can be avoided. Figure 2 The structure in the figure is a simple example, and does not reflect the control part of the soft start. The switch below the resistor is closed, and the current shock during startup can be avoided through the resistor. For example, the soft start circuit can also be implemented by using devices such as thermistors and MOS tubes, which are not described in detail in the embodiments of the present invention.

[0074] The energy storage air conditioning system may also include: a main controller (not shown in the figure), connected to the energy storage battery 13, the input end of the first converter 12 and the input end of the second converter 14, for determining the current power distribution control strategy of the energy storage air conditioning system, and under the current power distribution control strategy, according to the state of charge (SOC) of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, controlling the charging and discharging of the energy storage battery and the operation of the air conditioner. The main controller may be set separately from the energy storage and air conditioning, or its function may be integrated into the air conditioning control mainboard, and the air conditioning control mainboard may be used as the main controller. Through the main controller, the power supply control of the energy storage air conditioning system can be realized, the air conditioning distribution capacity and cable current carrying capacity can be reduced, the air conditioning power consumption can be reduced, and the economy of air conditioning power consumption can be guaranteed as much as possible.

[0075] The energy storage air conditioning system may further include: a battery management system 18, connected to the energy storage battery 13, for monitoring the status of the energy storage battery and providing protection for the energy storage battery; the battery management system 18, the first inverter 12 and the second inverter 14 have no main communication connection.

[0076] In this embodiment, the energy storage and air conditioning are designed to be integrated, the internal communication protocol is set, and the communication system of the first inverter 12, the second inverter 14 and the battery management system 18 has no external host connection. While realizing the energy response of the energy storage and air conditioning, the battery status can be monitored through the BMS to realize the integration of communication information of the energy storage and air conditioning. The battery management system 18 is also located inside the air conditioning outdoor unit.

[0077] The energy storage air conditioning system can also be provided with an auxiliary power supply 19, which is respectively connected to the power grid 15, the first converter 12, the second converter 14 and the battery management system 18, and is used to draw power from the power grid 15 to power the first converter 12, the second converter 14 and the battery management system 18. The power supply requirement of the auxiliary power supply is weak electricity, and the auxiliary power supply will start as soon as the power grid has electricity. Using the auxiliary power supply to power the first converter 12, the second converter 14 and the battery management system 18 can ensure the normal operation of the devices, and the auxiliary power supply draws power from the power grid instead of the battery side, which avoids the risk of over-discharge of the battery when not in use and completes the power-on of the control electricity. The auxiliary power supply 19 is located inside the air conditioner outdoor unit.

[0078] Embodiment 2

[0079] This embodiment provides a control method for the energy storage air conditioning system based on the energy storage air conditioning system described in Embodiment 1. Figure 3 is a flow chart of a control method of an energy storage air conditioning system provided in Embodiment 2 of the present invention. Figure 3 As shown, the method comprises the following steps:

[0080] S301, determining a current power distribution control strategy of the energy storage air conditioning system.

[0081] Among them, the power distribution control strategy refers to the strategy for adjusting and controlling the power supply of the energy storage air conditioning system from the power distribution and the power supply from the energy storage battery, that is, controlling the power supply to the air conditioner through the power distribution and / or the power supply to the air conditioner through the energy storage battery. Taking into account the factors of electricity economy and the power required for the air conditioner to meet the temperature control requirements, the power distribution control strategy includes: energy storage economic operation strategy, power limiting operation strategy and constant power operation strategy. The energy storage air conditioning system can be set to automatically select a suitable power distribution control strategy according to current needs. For example, when the user's cooling or heating needs are relatively small, a power limiting operation strategy is selected. For example, in the summer when electricity consumption is at its peak, an energy storage economic operation strategy is selected, thereby realizing adaptive self-optimization control of the energy storage air conditioning system. In addition, users can choose a power distribution control strategy that meets current needs according to actual needs, and can change the strategy at any time later.

[0082] S302, under the current power distribution control strategy, according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, control the charging and discharging of the energy storage battery and the operation of the air conditioner.

[0083] Among them, the state of charge of the energy storage battery can be obtained through the battery management system (Battery Management System, BMS). The power consumption of the air conditioner can be directly collected and monitored, or the power consumption can be calculated by collecting parameters such as power voltage. According to the peak and valley characteristics of electricity consumption, the electricity time period can be divided into peak period, valley period and flat period, and the electricity price is high during the peak period. According to the state of charge of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, the charging and discharging of the energy storage battery and the operation of the air conditioner can be reasonably controlled to reduce the power distribution capacity and electricity consumption of the air conditioner.

[0084] This embodiment integrates energy storage and air conditioning. By utilizing energy storage batteries, the charging and discharging of the energy storage batteries and the operation of the air conditioner can be controlled according to the charge state of the energy storage batteries in the energy storage air conditioning system, the power consumption of the air conditioner, and the current power consumption time period under the power distribution control strategy, thereby realizing power supply control of the air conditioner, thereby reducing the power distribution capacity of the air conditioner and the current carrying capacity of the cables, reducing the power consumption of the air conditioner, and ensuring the economy of the power consumption of the air conditioner as much as possible.

[0085] With respect to S302 , the specific control methods under each power distribution control strategy are described below.

[0086] (1) Energy storage economic operation strategy

[0087] refer to Figure 4When the energy storage air conditioning system is powered on, if the current power distribution control strategy is the energy storage economic operation strategy, determine whether the charge state of the energy storage battery meets the discharge requirements; if it meets the discharge requirements, determine whether the real-time power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, control the charging and discharging of the energy storage battery according to the current power consumption time period.

[0088] The power distribution threshold is a preset limit value of the power distribution capacity of the energy storage air conditioning system, which can be set according to the interface capacity of the energy storage air conditioning system connected to the power grid. For example, if the interface capacity is 5kw, the power distribution threshold can be set to 5kw, or it can be lower than 5kw. The discharge requirement refers to the SOC of the energy storage battery reaching a preset value.

[0089] Furthermore, the charging and discharging of the energy storage battery is controlled according to the current power consumption time period, including: if the current power consumption time period is a peak period, the energy storage battery is controlled to discharge to supply the air conditioner; if the current power consumption time period is a valley period, the energy storage battery is charged through the power grid; if the current power consumption time period is a normal period, the energy storage battery is controlled not to be charged or discharged. This method discharges during the peak period, and the power exceeding the distribution power threshold is supplemented by the discharge of the energy storage battery, reducing the power grid power consumption during the period of high electricity prices, charging during the valley period, and storing energy at a low electricity price, realizing the economy of energy storage and reducing power consumption as much as possible.

[0090] In actual application, the judgment order of time periods can be set. Figure 4 For example, first determine whether the current time is in the peak period. If so, execute energy storage discharge. If not, determine whether the current time is in the valley period. If so, execute energy storage charging. If not (indicating that it is in the normal period), control the energy storage battery to neither charge nor discharge.

[0091] If the power consumption of the air conditioner is not greater than the power distribution threshold, the energy storage battery is controlled to be neither charged nor discharged. If the power consumption of the air conditioner is not greater than the power distribution threshold, it means that the current power distribution can fully meet the power demand of the air conditioner, and there is no need to discharge the energy storage battery. Considering that the energy storage is mainly operated economically, the energy storage battery is controlled to be neither charged nor discharged to ensure economy.

[0092] If the state of charge of the energy storage battery does not meet the discharge requirements, the current state of the energy storage battery is determined according to the state of charge of the energy storage battery; if the energy storage battery is in an overcharge state or at the calibration moment, the energy storage battery is controlled not to be charged or discharged, and the step of judging whether the state of charge of the energy storage battery meets the discharge requirements is returned. Preferably, the step of judging whether the state of charge of the energy storage battery meets the discharge requirements can be returned after a preset delay to avoid frequent judgments and occupying system resources; if the energy storage battery is in an over-discharge state, the energy storage battery is forcibly charged until the state of charge requirements are met, and the step of judging whether the state of charge of the energy storage battery meets the discharge requirements is returned; if the energy storage battery is not in an over-charge state, at the calibration moment, or in an over-discharge state, a fault alarm is output.

[0093] Among them, overcharge means that the battery power reaches 100%, but the voltage level exceeds the rated level, and the voltage of the single cell floats high. The calibration moment refers to the calibration of the actual capacity of the battery and the capacity recorded in the circuit through the process of discharging and then charging after the battery power is charged to 100%. In this embodiment, during the overcharge or calibration moment, the energy storage battery is controlled not to be charged or discharged, and the voltage drops after the calibration is completed to meet the discharge requirements. In the over-discharge state, forced charging is performed until the SOC requirements are met, so as to execute the subsequent processes to ensure that the energy storage battery can be used normally.

[0094] This implementation method gives priority to the economic operation of energy storage, and controls the charging and discharging of the energy storage battery according to the battery charge state, air conditioning power consumption and current power consumption time period, discharges during peak hours, reduces grid power consumption during periods with high electricity prices, charges during valley hours, and stores energy at low electricity prices, thereby ensuring that the energy storage air conditioning system consumes electricity relatively constantly within the set distribution power threshold, saving electricity as much as possible and ensuring economy.

[0095] (2) Power-limited operation strategy

[0096] refer to Figure 5 When the energy storage air conditioning system is powered on, if the current power distribution control strategy is the power limiting operation strategy, it is determined whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, it is determined whether the charge state of the energy storage battery meets the discharge requirements; if it meets the discharge requirements, the energy storage battery is controlled to discharge to supply the air conditioner.

[0097] If the state of charge of the energy storage battery does not meet the discharge requirements, the power consumption of the air conditioner is reduced so that the power consumption is less than or equal to the power distribution power threshold. Specifically, the power consumption of the air conditioner can be reduced by reducing the compressor frequency or modifying the user-set temperature.

[0098] If the power consumption of the air conditioner is not greater than the distribution power threshold, determine whether the charge state of the energy storage battery is fully charged; if not, determine whether the current power consumption period is a valley period; if it is a valley period, charge the energy storage battery through the power grid until the charge state of the energy storage battery meets the charge state requirement, and return to the step of determining whether the power consumption of the air conditioner is greater than the distribution power threshold; if not, wait for the valley period to charge the energy storage battery.

[0099] If the state of charge of the energy storage battery is fully charged, the power consumption of the air conditioner is increased without exceeding the power distribution power threshold, and the process returns to the step of determining whether the power consumption of the air conditioner is greater than the power distribution power threshold.

[0100] This implementation method takes power limitation of the energy storage air conditioning system as the primary goal, and secondly meets the economic operation of energy storage. The energy storage discharge is judged and controlled according to the air conditioning power consumption and battery charge state, and the discharge of the energy storage battery is used to reduce the air conditioning directly drawing power from the grid, ensuring that the energy storage air conditioning system operates below the distribution power threshold. The charging of the energy storage battery is controlled according to the current power consumption time period, and charging is carried out during the off-peak period, storing energy at a low electricity price, and saving electricity consumption.

[0101] (3) Constant power operation strategy

[0102] refer to Figure 6 , when the energy storage air conditioning system is powered on, if the current power distribution control strategy is a constant power operation strategy, the power consumption of the air conditioner is controlled to be constant at the preset power, and it is determined whether the power consumption of the air conditioner is greater than the power distribution power threshold;

[0103] If it is greater than the distribution power threshold, determine whether the charge state of the energy storage battery meets the discharge requirements; if it meets the discharge requirements, control the energy storage battery to discharge to supply the air conditioner; if it does not meet the discharge requirements, consider reducing power operation, for example, by reducing the compressor frequency or modifying the user-set temperature to reduce the power consumption to equal to or below the distribution power threshold.

[0104] If it is not greater than the distribution power threshold, determine whether the charge state of the energy storage battery is fully charged. If it is fully charged, control the energy storage battery to neither charge nor discharge. If it is not fully charged, control the energy storage battery to charge during the valley period.

[0105] This implementation method is based on the constant power operation of the energy storage air conditioning system, and secondly meets the energy storage economic operation. The energy storage air conditioning system operates at a fixed preset power. If the power distribution threshold does not reach the preset power, the energy storage battery is used to make up the difference in power. When the power distribution threshold is greater than or equal to the preset power and is in the valley period, the partially charged energy storage battery is charged, optimizing the air conditioning operation while ensuring energy-saving charging of the energy storage battery.

[0106] Embodiment 3

[0107] Based on the same inventive concept as the control method of the energy storage air conditioning system described in Example 2, this embodiment provides a control device for the energy storage air conditioning system, which can be used to implement the control method of the energy storage air conditioning system described in the above embodiment. The device can be implemented by software and / or hardware, and the device can generally be integrated into a main controller, for example, a main controller separately provided outside the air conditioning control mainboard, or the function can be integrated into the air conditioning control mainboard.

[0108] Figure 7 is a structural block diagram of a control device for an energy storage air conditioning system provided in Embodiment 3 of the present invention. Figure 7 As shown, the device comprises:

[0109] A determination module 71 is used to determine the current power distribution control strategy of the energy storage air conditioning system;

[0110] The control module 72 is used to control the charging and discharging of the energy storage battery and the operation of the air conditioner under the current power distribution control strategy according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period.

[0111] Optionally, the control module 72 includes: a first control unit, used to determine whether the charge state of the energy storage battery meets the discharge requirements when the current power distribution control strategy is the energy storage economic operation strategy; if the discharge requirements are met, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, control the charging and discharging of the energy storage battery according to the current power consumption time period.

[0112] Furthermore, the first control unit is specifically used to: if the current power consumption time period is a peak period, control the energy storage battery to discharge to supply the air conditioner; if the current power consumption time period is a valley period, charge the energy storage battery through the power grid; if the current power consumption time period is a normal period, control the energy storage battery not to charge or discharge.

[0113] Furthermore, the first control unit is also used to: if the power consumption of the air conditioner is not greater than the power distribution power threshold, control the energy storage battery to neither charge nor discharge.

[0114] Furthermore, the first control unit is also used for: if the state of charge of the energy storage battery does not meet the discharge requirement, determining the current state of the energy storage battery according to the state of charge of the energy storage battery; if the energy storage battery is in an overcharge state or at the calibration moment, controlling the energy storage battery to neither charge nor discharge, and returning to the step of determining whether the state of charge of the energy storage battery meets the discharge requirement; if the energy storage battery is in an over-discharge state, forcibly charging the energy storage battery until the state of charge requirement is met, and returning to the step of determining whether the state of charge of the energy storage battery meets the discharge requirement; if the energy storage battery is not in an overcharge state, at the calibration moment, or in an over-discharge state, outputting a fault alarm.

[0115] Optionally, the control module 72 includes: a second control unit, used to determine whether the power consumption of the air conditioner is greater than the power distribution power threshold when the current power distribution control strategy is a limited power operation strategy; if it is greater than the power distribution power threshold, determine whether the charge state of the energy storage battery meets the discharge requirements; if it meets the discharge requirements, control the energy storage battery to discharge to supply the air conditioner.

[0116] Furthermore, the second control unit is also used to: if the charge state of the energy storage battery does not meet the discharge requirement, reduce the power consumption of the air conditioner so that the power consumption is less than or equal to the distribution power threshold.

[0117] Furthermore, the second control unit is also used for: if the power consumption of the air conditioner is not greater than the distribution power threshold, determining whether the charge state of the energy storage battery is fully charged; if it is not fully charged, determining whether the current power consumption period is a valley period; if it is a valley period, charging the energy storage battery through the power grid until the charge state of the energy storage battery meets the charge state requirement, and returning to the step of determining whether the power consumption of the air conditioner is greater than the distribution power threshold; if it is not a valley period, waiting for the valley period to charge the energy storage battery.

[0118] Furthermore, the second control unit is also used to: if the charge state of the energy storage battery is fully charged, then on the premise of not exceeding the distribution power threshold, increase the power consumption of the air conditioner, and return to the step of determining whether the power consumption of the air conditioner is greater than the distribution power threshold.

[0119] Optionally, the control module 72 includes: a third control unit, used for controlling the power consumption of the air conditioner to be constant at a preset power when the current power distribution control strategy is a constant power operation strategy, and determining whether the power consumption of the air conditioner is greater than the power distribution power threshold; if greater than the power distribution power threshold, determining whether the charge state of the energy storage battery meets the discharge requirement; if the discharge requirement is met, controlling the energy storage battery to discharge to supply the air conditioner; if not greater than the power distribution power threshold, determining whether the charge state of the energy storage battery is fully charged, and if it is fully charged, controlling the energy storage battery not to be charged or discharged, and if it is not fully charged, controlling the energy storage battery to be charged during the valley period.

[0120] The above device can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0121] This embodiment further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the control method of the energy storage air conditioning system described in the second embodiment of the present invention is implemented.

[0122] In summary, the energy storage air conditioning system and its control method and control device in the embodiment of the present invention integrate energy storage and air conditioning, electrical connection, and communication information. Through the energy storage battery and the corresponding control method, it is possible to avoid the problem of large source-load flow fluctuations, large air conditioning power distribution capacity and cable current carrying capacity caused by drastic power changes in the air conditioning load, and avoid the uneconomical problem of the maximum air conditioning power consumption at the peak of electricity prices.

[0123] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0124] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0125] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy storage air conditioning system, characterized in that: include: A compressor, a first converter, an energy storage battery and a second converter; The energy storage battery and the second converter are located inside the air conditioner outdoor unit, and the energy storage battery is connected to the power grid through the second converter; The compressor is connected to the grid via the first converter; The energy storage battery is used to charge and discharge according to the current power distribution control strategy of the energy storage air conditioning system, wherein the energy storage battery is discharged to power the air conditioner; The energy storage air conditioning system further includes: a main controller connected to the energy storage battery, the input end of the first converter and the input end of the second converter, and used to determine the current power distribution control strategy of the energy storage air conditioning system, and under the current power distribution control strategy, control the charging and discharging of the energy storage battery and the operation of the air conditioning according to the state of charge of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period; Distribution control strategies include: energy storage economic operation strategy, power-limited operation strategy and constant power operation strategy; The main controller is used for: If the current power distribution control strategy is the energy storage economic operation strategy, determine whether the state of charge of the energy storage battery meets the discharge requirement; if the discharge requirement is met, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, control the charging and discharging of the energy storage battery according to the current power consumption time period; If the current power distribution control strategy is a power-limited operation strategy, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, determine whether the charge state of the energy storage battery meets the discharge requirement; if it meets the discharge requirement, control the energy storage battery to discharge to supply the air conditioner; If the current power distribution control strategy is a constant power operation strategy, the power consumption of the air conditioner is controlled to be constant at a preset power, and it is determined whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, it is determined whether the charge state of the energy storage battery meets the discharge requirement, and if it meets the discharge requirement, the energy storage battery is controlled to discharge to supply the air conditioner; if it is not greater than the power distribution power threshold, it is determined whether the charge state of the energy storage battery is fully charged, and if it is fully charged, the energy storage battery is controlled not to be charged or discharged, and if it is not fully charged, the energy storage battery is controlled to be charged during the valley period.

2. The energy storage air conditioning system according to claim 1, characterized in that: The energy storage air conditioning system also includes: A switch, one end of the switch is connected to the output end of the second converter, and the other end is connected to the energy storage battery, and the switch is used to stop the charging and discharging of the energy storage battery when it is disconnected.

3. The energy storage air conditioning system according to claim 1, characterized in that: The energy storage air conditioning system also includes: A soft start circuit, wherein an input end of the soft start circuit is connected to the power grid, and an output end of the soft start circuit is connected to an input end of the first converter and an input end of the second converter.

4. The energy storage air conditioning system according to claim 1, characterized in that: The energy storage air conditioning system also includes: A battery management system, connected to the energy storage battery, for monitoring the status of the energy storage battery and providing protection for the energy storage battery; The battery management system, the first converter and the second converter have no master communication connection.

5. The energy storage air conditioning system according to claim 4, characterized in that: The energy storage air conditioning system also includes: An auxiliary power supply is respectively connected to the power grid, the first converter, the second converter and the battery management system, and is used to draw power from the power grid to supply power to the first converter, the second converter and the battery management system.

6. The energy storage air conditioning system according to claim 1, characterized in that: If the power grid is a DC microgrid, the first converter is DC / AC and the second converter is DC / DC; If the power grid is an AC microgrid, the first converter is AC / AC and the second converter is AC / DC; If the power grid is an AC / DC hybrid microgrid, the first converter is DC / AC or AC / AC, and the second converter is DC / DC or AC / DC.

7. A control method for an energy storage air conditioning system, applied to the energy storage air conditioning system according to any one of claims 1 to 6, characterized in that: The method comprises: Determining a current power distribution control strategy of the energy storage air conditioning system; Under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period; Distribution control strategies include: energy storage economic operation strategy, power-limited operation strategy and constant power operation strategy; Under the current power distribution control strategy, the charging and discharging of the energy storage battery and the operation of the air conditioner are controlled according to the charge state of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period, including: If the current power distribution control strategy is the energy storage economic operation strategy, determine whether the state of charge of the energy storage battery meets the discharge requirement; if the discharge requirement is met, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, control the charging and discharging of the energy storage battery according to the current power consumption time period; If the current power distribution control strategy is a power-limited operation strategy, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, determine whether the charge state of the energy storage battery meets the discharge requirement; if it meets the discharge requirement, control the energy storage battery to discharge to supply the air conditioner; If the current power distribution control strategy is a constant power operation strategy, the power consumption of the air conditioner is controlled to be constant at a preset power, and it is determined whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, it is determined whether the charge state of the energy storage battery meets the discharge requirement, and if it meets the discharge requirement, the energy storage battery is controlled to discharge to supply the air conditioner; if it is not greater than the power distribution power threshold, it is determined whether the charge state of the energy storage battery is fully charged, and if it is fully charged, the energy storage battery is controlled not to be charged or discharged, and if it is not fully charged, the energy storage battery is controlled to be charged during the valley period.

8. The method according to claim 7, characterized in that When the current power distribution control strategy is an energy storage economic operation strategy, controlling the charging and discharging of the energy storage battery according to the current power consumption time period includes: If the current power consumption time period is a peak period, controlling the energy storage battery to discharge to supply the air conditioner; If the current power consumption time period is a valley period, charging the energy storage battery through the power grid; If the current power consumption time period is a normal period, the energy storage battery is controlled to neither be charged nor discharged.

9. The method according to claim 7, characterized in that: When the current power distribution control strategy is an energy storage economic operation strategy, the method further includes: If the power consumption of the air conditioner is not greater than the power distribution power threshold, the energy storage battery is controlled to neither be charged nor discharged.

10. The method according to claim 7, characterized in that When the current power distribution control strategy is an energy storage economic operation strategy, the method further includes: If the state of charge of the energy storage battery does not meet the discharge requirement, determining the current state of the energy storage battery according to the state of charge of the energy storage battery; If the energy storage battery is in an overcharge state or at the calibration time, the energy storage battery is controlled to be neither charged nor discharged, and the process returns to the step of determining whether the state of charge of the energy storage battery meets the discharge requirement; If the energy storage battery is in an over-discharge state, the energy storage battery is forcibly charged until the state of charge requirement is met, and the step of returning to determine whether the state of charge of the energy storage battery meets the discharge requirement is performed; If the energy storage batteries are not in an overcharge state, calibration time, or over-discharge state, a fault alarm is output.

11. The method according to claim 7, characterized in that In the case where the current power distribution control strategy is a power-limited operation strategy, the method further includes: If the state of charge of the energy storage battery does not meet the discharge requirement, the power consumption of the air conditioner is reduced so that the power consumption is less than or equal to the distribution power threshold.

12. The method according to claim 7, characterized in that In the case where the current power distribution control strategy is a power-limited operation strategy, the method further includes: If the power consumption of the air conditioner is not greater than the power distribution power threshold, determining whether the state of charge of the energy storage battery is fully charged; If it is not in full power state, determine whether the current power consumption period is a valley period; If it is a valley period, the energy storage battery is charged through the power grid until the state of charge of the energy storage battery meets the state of charge requirement, and the process returns to the step of determining whether the power consumption of the air conditioner is greater than the power distribution power threshold; If it is not a valley period, then wait for the valley period to charge the energy storage battery.

13. The method according to claim 7, characterized in that In the case where the current power distribution control strategy is a power-limited operation strategy, the method further includes: If the state of charge of the energy storage battery is fully charged, the power consumption of the air conditioner is increased without exceeding the power distribution power threshold, and the process returns to the step of determining whether the power consumption of the air conditioner is greater than the power distribution power threshold.

14. A control device for an energy storage air conditioning system, characterized in that: include: A determination module, used to determine the current power distribution control strategy of the energy storage air conditioning system; A control module, configured to control the charging and discharging of the energy storage battery and the operation of the air conditioner according to the state of charge of the energy storage battery in the energy storage air conditioning system, the power consumption of the air conditioner and the current power consumption time period under the current power distribution control strategy; Distribution control strategies include: energy storage economic operation strategy, power-limited operation strategy and constant power operation strategy; The control module comprises: The first control unit is used to determine whether the state of charge of the energy storage battery meets the discharge requirement when the current power distribution control strategy is the energy storage economic operation strategy; if the discharge requirement is met, determine whether the power consumption of the air conditioner is greater than the power distribution power threshold; if greater than the power distribution power threshold, control the charging and discharging of the energy storage battery according to the current power consumption time period; A second control unit is used to determine whether the power consumption of the air conditioner is greater than the power distribution power threshold when the current power distribution control strategy is a power-limited operation strategy; if it is greater than the power distribution power threshold, determine whether the charge state of the energy storage battery meets the discharge requirement; if it meets the discharge requirement, control the energy storage battery to discharge to supply the air conditioner; The third control unit is used for controlling the power consumption of the air conditioner to be constant at a preset power when the current power distribution control strategy is a constant power operation strategy, and judging whether the power consumption of the air conditioner is greater than the power distribution power threshold; if it is greater than the power distribution power threshold, judging whether the charge state of the energy storage battery meets the discharge requirement, and if it meets the discharge requirement, controlling the energy storage battery to discharge to supply the air conditioner; if it is not greater than the power distribution power threshold, judging whether the charge state of the energy storage battery is a fully charged state, and if it is a fully charged state, controlling the energy storage battery not to be charged or discharged, and if it is not a fully charged state, controlling the energy storage battery to be charged during a valley period.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by the processor, the control method of the energy storage air conditioning system according to any one of claims 7 to 13 is implemented.

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