EMS energy management method and energy management system

Abstract

The present invention relates to an EMS energy management method and an energy management system, and relates to the field of photovoltaic new energy. The method comprises: obtaining the power state of multiple batteries and the inverter power of multiple energy storage inverters; judging whether the sum of multiple inverter powers is greater than zero; if the sum of multiple inverter powers is greater than zero, obtaining multiple inverter reference powers when the energy management system is charged and discharged through a first calculation model and multiple power states; obtaining multiple battery reference powers and multiple battery reference currents according to the multiple inverter reference powers. Multiple battery currents of the energy management system are obtained, PID adjustment is performed on the multiple battery currents and multiple battery reference currents, and PWM signals are output to realize energy management. The beneficial effect of the present invention is that when the state of the load unit itself changes, the time required for the SOC to change from inconsistent values ​​to consistent values ​​can be effectively shortened.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic new energy, and in particular to an EMS energy management method and an energy management system. Background Art

[0002] With the rapid development of the photovoltaic new energy industry, the shipment volume of EMS energy management system continues to rise. EMS energy management system is used to achieve effective support for load units through energy management, while minimizing the electricity cost of load units in terms of mains electricity.

[0003] At present, the core issue of EMS energy management system technology upgrade is that users have increasingly higher requirements for energy management of energy storage inverters and batteries. Therefore, the industry needs to develop an EMS energy management method to meet users' increasing energy management requirements. Summary of the invention

[0004] The present invention proposes an EMS energy management method that can meet the increasing energy management requirements of users. The inventor has found through research that the load unit in the photovoltaic new energy scenario includes two states. The first state is composed only of the user's household appliances, and the second state is composed of the inverter grid-connected system and household appliances. When the state of the load unit itself changes (for example, switching between the first state and the second state), the charge / discharge amount of the load unit will also change accordingly, and this scenario will bring technical problems: the inverter grid-connected system will charge, and household appliances will use electricity. This state change is determined by the user at the load end. The state change process will affect the EMS energy management system, and its SOC power redistribution will take a long time.

[0005] In a first aspect, the present invention proposes an EMS energy management method, which is used for an energy management system in a grid-connected state; the EMS energy management method comprises: S10, obtaining the power status of multiple batteries and the inverter power of multiple energy storage inverters; S20, judging whether the sum of the multiple inverter powers is greater than zero; S30, if the sum of the multiple inverter powers is greater than zero, obtaining multiple inverter reference powers during charging and discharging of the energy management system through a first calculation model and multiple power statuses; S40, obtaining multiple battery reference powers and multiple battery reference currents according to the multiple inverter reference powers; S50, obtaining multiple battery currents of the energy management system, performing PID adjustment on the multiple battery currents and multiple battery reference currents, and outputting PWM signals to realize energy management.

[0006] Its further technical solution is that before the S40 obtains multiple battery reference powers and multiple battery reference currents based on multiple inverter reference powers, it includes: S31, if the sum of the multiple inverter powers is not greater than zero, obtain multiple inverter reference powers when the energy management system is charging and discharging through a second calculation model and multiple power states.

[0007] Its further technical solution is that the first module includes battery A and energy storage inverter A, the second module includes battery B and energy storage inverter B, and the third module includes battery C and energy storage inverter C; the S10 obtains the power status of multiple batteries and the inverter power of multiple energy storage inverters, including: obtaining three power statuses of three modules, including the power status SOCA of battery A, the power status SOCB of battery B, and the power status SOCC of battery C; obtaining three inverter powers of three modules, including the inverter power INPA of energy storage inverter A, the inverter power INPB of energy storage inverter B, and the inverter power INPC of energy storage inverter C.

[0008] Its further technical solution is that the total state of charge SOCT is equal to the sum of the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C; if the sum of multiple inverter powers is greater than zero, the S30 obtains multiple inverter reference powers when the energy management system is charged and discharged through the first calculation model and multiple power states, including: if the total inverter power INPT of the sum of the three inverter powers is greater than zero, the inverter discharges to the load, and the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C are substituted into the first calculation model to obtain three inverter reference powers when the energy management system is charged and discharged, including energy storage The inverter reference power INPRA of inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRC of energy storage inverter C; according to the first calculation model, the inverter reference power INPRA of energy storage inverter A is equal to the total inverter power INPT multiplied by the state of charge SOCA of battery A, divided by the total state of charge SOCT; the inverter reference power INPRB of energy storage inverter B is equal to the total inverter power INPT multiplied by the state of charge SOCB of battery B, divided by the total state of charge SOCT; the inverter reference power INPRC of energy storage inverter C is equal to the total inverter power INPT multiplied by the state of charge SOCC of battery C, divided by the total state of charge SOCT.

[0009] Its further technical solution is that, in S31, if the sum of multiple inverter powers is not greater than zero, multiple inverter reference powers are obtained when the energy management system is charged and discharged through a second calculation model and multiple power states, including: if the total inverter power INPT of the sum of the three inverter powers is not greater than zero, the inverter discharges to the load, and the power state SOCA of battery A, the power state SOCB of battery B, and the power state SOCC of battery C are substituted into the second calculation model to obtain three inverter reference powers when the energy management system is charged and discharged, including the inverter reference power INPRA of energy storage inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRB of energy storage inverter C. The inverter reference power INPRC of inverter C; according to the second calculation model, the inverter reference power INPRA of the energy storage inverter A is equal to the difference between 100% and the state of charge SOCA of battery A, multiplied by the total inverter power INPT, and divided by the total state of charge SOCT; the inverter reference power INPRB of the energy storage inverter B is equal to the difference between 100% and the state of charge SOCB of battery B, multiplied by the total inverter power INPT, and divided by the total state of charge SOCT; the inverter reference power INPRC of the energy storage inverter C is equal to the difference between 100% and the state of charge SOCC of battery C, multiplied by the total inverter power INPT, and divided by the total state of charge SOCT.

[0010] Its further technical solution is that the multiple meter powers include the meter power MCA of energy storage inverter A, the meter power MCB of energy storage inverter B, and the meter power MCC of energy storage inverter C; the multiple meter distribution powers include the distribution power MeterA of energy storage inverter A, the distribution power MeterB of energy storage inverter B, and the distribution power MeterC of energy storage inverter C; the port meter of the energy management system corresponds to the port meter power MP; the S40 obtains multiple battery reference powers and multiple battery reference currents according to multiple inverter reference powers, including: according to the inverter reference power INPRA of energy storage inverter A and the inverter power INPA of energy storage inverter A, the difference between the two is obtained to obtain the compensation power ErrA of energy storage inverter A, and then multiply it by the first coefficient for KP Adjust to obtain the meter power MCA of the energy storage inverter A; according to the inverter reference power INPRB of the energy storage inverter B and the inverter power INPB of the energy storage inverter B, the compensation power ErrB of the energy storage inverter B is obtained by the difference between the two, and then multiplied by the first coefficient for KP adjustment to obtain the meter power MCB of the energy storage inverter B; according to the inverter reference power INPRC of the energy storage inverter C and the inverter power INPC of the energy storage inverter C, the compensation power ErrC of the energy storage inverter C is obtained by the difference between the two, and then multiplied by the first coefficient for KP adjustment to obtain the meter power MCC of the energy storage inverter C; according to the meter power MCA of the energy storage inverter A, the meter power MCB of the energy storage inverter B, and the meter power MCC of the energy storage inverter C, the total meter power MCT is obtained by the sum of the three.

[0011] Its further technical solution is that the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCA of the energy storage inverter A is added to obtain the allocated power MeterA of the energy storage inverter A; the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCB of the energy storage inverter A is added to obtain the allocated power MeterB of the energy storage inverter B; the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCC of the energy storage inverter A is added to obtain the allocated power MeterC of the energy storage inverter C; the battery power BPA of battery A is added to the allocated power MeterA of the energy storage inverter A, and then multiplied by the first coefficient to obtain the battery reference power BPRA of battery A; the battery power BPB of battery B is added to the allocated power Meter of the energy storage inverter B rB, and then multiply it by the first coefficient to obtain the battery reference power BPRB of battery B; the battery power BPC of battery C plus the allocated power MeterC of the energy storage inverter C, and then multiply it by the first coefficient to obtain the battery reference power BPRC of battery C; the battery reference power BPRA of battery A is divided by the battery voltage BVA of battery A to obtain the current reference sampling value BCRA of battery A; the battery reference power BPRB of battery B is divided by the battery voltage BVB of battery B to obtain the current reference sampling value BCRB of battery B; the battery reference power BPRC of battery C is divided by the battery voltage BVC of battery C to obtain the current reference sampling value BCRC of battery C; the battery reference power BPRA of battery A, the battery reference power BPRB of battery B, and the battery reference power BPRC of battery C are combined into multiple battery reference powers; the current reference sampling value BCRA of battery A, the current reference sampling value BCRB of battery B, and the current reference sampling value BCRC of battery C are combined into multiple battery reference currents.

[0012] Its further technical solution is that the S50 obtains multiple battery currents of the energy management system, performs PID adjustment on the multiple battery currents and multiple battery reference currents, and outputs a PWM signal to realize energy management, including: obtaining multiple battery currents of the energy management system, including the current sampling value BCA of battery A, the current sampling value BCB of battery B, and the current sampling value BCC of battery C; performing PID adjustment on the current reference sampling value BCRA of battery A, the current reference sampling value BCRB of battery B, the current reference sampling value BCRC of battery C, the current sampling value BCA of battery A, the current sampling value BCB of battery B, and the current sampling value BCC of battery C, and outputting a PWM signal to realize energy management.

[0013] In a second aspect, the present invention proposes an energy management system, which includes a unit for executing the method described in the first aspect. The energy management system also includes a first module, a second module, a third module, an EMS control unit, an electric meter unit, a load unit, and a mains unit; the first module, the second module, the third module, the load unit, and the mains unit are all connected to the electric meter unit; the EMS control unit is connected to the first module, the second module, the third module, and the electric meter unit via a 485 communication line.

[0014] Its further technical solution is that the first module of the energy management system includes a battery A and an energy storage inverter A connected to each other, the second module includes a battery B and an energy storage inverter B connected to each other, and the third module includes a battery C and an energy storage inverter C connected to each other; the energy storage inverter A, the energy storage inverter B, the energy storage inverter C, the load unit, and the AC power unit are all connected to the electric meter unit; the EMS control unit is connected to the energy storage inverter A, the energy storage inverter B, the energy storage inverter C, and the electric meter unit via a 485 communication line.

[0015] After research, the inventor found that the load unit in the photovoltaic new energy scene includes two states. The first state is composed only of the user's household appliances, and the second state is composed of the inverter grid-connected system and household appliances. When the state of the load unit itself changes (for example, switching between the first state and the second state), the charge / discharge amount of the load unit will also change accordingly, and this scenario will bring technical problems: the inverter grid-connected system will charge, and the household appliances will use electricity. This state change is determined by the user at the load end. The state change process will affect the EMS energy management system, and its SOC power redistribution will take a long time. In order to solve the above problems, the solution proposed by the present invention can effectively shorten the time required for SOC to change from inconsistent values ​​to consistent values ​​when the state of the load unit itself changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1A schematic diagram of the flow of an EMS energy management method provided in an embodiment of the present invention.

[0019] Figure 2 Another schematic diagram of the process of the EMS energy management method provided by the embodiment of the present invention.

[0020] Figure 3 A block diagram of an energy management system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of 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.

[0022] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or other features, integers, steps, operations, elements, components and / or combinations thereof.

[0023] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0024] It should be further understood that the term "and / or" used in the present description and the appended claims refers to one or any combination and all possible combinations of the associated listed items, and includes these combinations.

[0025] As used in this specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0026] Example 1

[0027] See also Figure 1-Figure 3 , Figure 1A flowchart of an EMS energy management method provided by an embodiment of the present invention. An embodiment of the present invention proposes an EMS energy management method, which is used in an energy management system in a grid-connected state; the energy management system executes the method as a control unit, and the SOC values ​​of multiple batteries in the energy management system are different from each other; the EMS energy management method includes:

[0028] S10, obtaining the power status of multiple batteries and the inverter power of multiple energy storage inverters.

[0029] S20, determining whether the sum of the multiple inverter powers is greater than zero.

[0030] S30: If the sum of the multiple inverter powers is greater than zero, obtain multiple inverter reference powers during charging and discharging of the energy management system through a first calculation model and multiple power states.

[0031] S40, acquiring multiple battery reference powers and multiple battery reference currents according to multiple inverter reference powers.

[0032] S50, obtaining multiple battery currents of the energy management system, performing PID adjustment on the multiple battery currents and multiple battery reference currents, and outputting PWM signals to realize energy management.

[0033] In one embodiment, before S40 acquires multiple battery reference powers and multiple battery reference currents according to multiple inverter reference powers, it includes:

[0034] S31, if the sum of the multiple inverter powers is not greater than zero, obtain multiple inverter reference powers during charging and discharging of the energy management system through a second calculation model and multiple power states.

[0035] In the above scheme, multiple battery currents of the energy management system are obtained, PID adjustment is performed on the multiple battery currents and multiple battery reference currents, and a PWM signal is output to realize closed-loop control of the battery current. In one embodiment, the SOC values ​​of the multiple batteries in the energy management system are different from each other, and the difference between the maximum SOC value and the minimum SOC value of the multiple batteries is greater than 20%.

[0036] In the prior art, the core issue of the EMS energy management system in terms of technology upgrade is that users have increasingly higher requirements for energy management of energy storage inverters and batteries. The above solution can meet users' increasing energy management requirements.

[0037] In one embodiment, the first module includes a battery A and an energy storage inverter A, the second module includes a battery B and an energy storage inverter B, and the third module includes a battery C and an energy storage inverter C; the S10 obtains the power status of multiple batteries and the inverter power of multiple energy storage inverters, including:

[0038] S101, obtaining three power states of three modules, including the power state SOCA of battery A, the power state SOCB of battery B, and the power state SOCC of battery C.

[0039] S102, obtaining three inverter powers of three modules, including the inverter power INPA of energy storage inverter A, the inverter power INPB of energy storage inverter B, and the inverter power INPC of energy storage inverter C.

[0040] In one embodiment, the step S20 of determining whether the sum of the plurality of inverter powers is greater than zero includes:

[0041] S201, calculate the inverter power INPA of the energy storage inverter A, the inverter power INPB of the energy storage inverter B, and the inverter power INPC of the energy storage inverter C, and obtain the total inverter power INPT by adding the sum of the three.

[0042] S202, determining whether the total inverter power INPT which is the sum of the three inverter powers is greater than zero.

[0043] In one embodiment, the total state of charge SOCT is equal to the sum of the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C; if the sum of the multiple inverter powers is greater than zero, the S30 obtains multiple inverter reference powers when the energy management system is charged and discharged through the first calculation model and the multiple power states, including:

[0044] Furthermore, if the total inverter power INPT of the sum of the three inverter powers is greater than zero, the inverter discharges to the load, and the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C are substituted into the first calculation model to obtain three inverter reference powers during charging and discharging of the energy management system, including the inverter reference power INPRA of energy storage inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRC of energy storage inverter C.

[0045] Further, according to the first calculation model, the inverter reference power INPRA of the energy storage inverter A is equal to the inverter total power INPT multiplied by the state of charge SOCA of the battery A divided by the total state of charge SOCT.

[0046] Further, the inverter reference power INPRB of the energy storage inverter B is equal to the inverter total power INPT multiplied by the power state SOCB of the battery B divided by the total power state SOCT.

[0047] Further, the inverter reference power INPRC of the energy storage inverter C is equal to the inverter total power INPT multiplied by the state of charge SOCC of the battery C divided by the total state of charge SOCT.

[0048] In one embodiment, if the sum of the multiple inverter powers is not greater than zero, the step S31 obtains multiple inverter reference powers during charging and discharging of the energy management system through a second calculation model and multiple power states, including:

[0049] Furthermore, if the total inverter power INPT of the sum of the three inverter powers is not greater than zero, the inverter discharges to the load, and the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C are substituted into the second calculation model to obtain three inverter reference powers during charging and discharging of the energy management system, including the inverter reference power INPRA of energy storage inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRC of energy storage inverter C. Among them, if the total inverter power is not greater than zero, it means that there is an external photovoltaic grid-connected inverter to charge battery A, battery B, and battery C.

[0050] Further, according to the second calculation model, the inverter reference power INPRA of the energy storage inverter A is equal to the difference between 100% and the state of charge SOCA of the battery A, multiplied by the total inverter power INPT, and divided by the total state of charge SOCT. Among them, there are two cases of the total state of charge SOCT: the first case is when the total inverter power is greater than zero, the total power SOCT=SOCA+SOCB+SOCT; the second case is when the total inverter power is less than zero, the total power SOCT=(100%-SOCA)+(100%-SOCB)+(100%-SOCC).

[0051] Furthermore, the inverter reference power INPRB of the energy storage inverter B is equal to the difference between 100% and the state of charge SOCB of the battery B, multiplied by the total inverter power INPT, divided by the total state of charge SOCT.

[0052] Furthermore, the inverter reference power INPRC of the energy storage inverter C is equal to the difference between 100% and the state of charge SOCC of the battery C, multiplied by the total inverter power INPT, divided by the total state of charge SOCT.

[0053] In one embodiment, the multiple meter powers include the meter power MCA of energy storage inverter A, the meter power MCB of energy storage inverter B, and the meter power MCC of energy storage inverter C; the multiple meter allocation powers include the allocation power MeterA of energy storage inverter A, the allocation power MeterB of energy storage inverter B, and the allocation power MeterC of energy storage inverter C; the port meter of the energy management system corresponds to the port meter power MP; the S40 obtains multiple battery reference powers and multiple battery reference currents according to multiple inverter reference powers, including:

[0054] Further, according to the inversion reference power INPRA of energy storage inverter A and the inversion power INPA of energy storage inverter A, the compensation power ErrA of energy storage inverter A is obtained by the difference between the two, and then multiplied by the first coefficient for KP adjustment to obtain the meter power MCA of energy storage inverter A; according to the inversion reference power INPRB of energy storage inverter B and the inversion power INPB of energy storage inverter B, the compensation power ErrB of energy storage inverter B is obtained by the difference between the two, and then multiplied by the first coefficient for KP adjustment to obtain the meter power MCB of energy storage inverter B; according to the inversion reference power INPRC of energy storage inverter C and the inversion power INPC of energy storage inverter C, the compensation power ErrC of energy storage inverter C is obtained by the difference between the two, and then multiplied by the first coefficient for KP adjustment to obtain the meter power MCC of energy storage inverter C. Furthermore, the sum of the meter powers allocated to the first module, ie, module A, the second module, ie, module B, and the third module, ie, module C, must be equal to the value of the total meter power port meter power MP.

[0055] Further, according to the meter power MCA of energy storage inverter A, the meter power MCB of energy storage inverter B, and the meter power MCC of energy storage inverter C, the total meter power MCT is obtained by summing the three; the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCA of energy storage inverter A is added to obtain the allocated power MeterA of energy storage inverter A; the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCB of energy storage inverter A is added to obtain the allocated power MeterB of energy storage inverter B; the difference between the port meter power MP and the total meter power MCT is divided by the value three to obtain the virtual power VP of the energy management system, and then the meter power MCC of energy storage inverter A is added to obtain the allocated power MeterC of energy storage inverter C.

[0056] Furthermore, the three energy storage inverters obtain the battery power and voltage power allocated by the energy management system, including the battery power BPA of battery A, the battery power BPB of battery B, the battery power BPC of battery C, the battery voltage BVA of battery A, the battery voltage BVB of battery B, and the battery voltage BVC of battery C; the battery power BPA of battery A plus the allocated power MeterA of energy storage inverter A are multiplied by the first coefficient to obtain the battery reference power BPRA of battery A; the battery power BPB of battery B plus the allocated power MeterB of energy storage inverter B are multiplied by the first coefficient to obtain the battery reference power BPRA of battery A. The battery reference power BPRB of battery B; the battery power BPC of battery C plus the allocated power MeterC of energy storage inverter C, multiplied by the first coefficient, obtain the battery reference power BPRC of battery C; the battery reference power BPRA of battery A divided by the battery voltage BVA of battery A, obtain the current reference sampling value BCRA of battery A; the battery reference power BPRB of battery B divided by the battery voltage BVB of battery B, obtain the current reference sampling value BCRB of battery B; the battery reference power BPRC of battery C divided by the battery voltage BVC of battery C, obtain the current reference sampling value BCRC of battery C. Among them, the three energy storage inverters obtain the battery power and voltage power allocated by the energy management system, specifically corresponding to the three energy storage inverters obtaining the battery current, battery voltage, and calculated battery power collected by their own Hall sensors.

[0057] Furthermore, the battery reference power BPRA of battery A, the battery reference power BPRB of battery B, and the battery reference power BPRC of battery C are combined into multiple battery reference powers; the current reference sampling value BCRA of battery A, the current reference sampling value BCRB of battery B, and the current reference sampling value BCRC of battery C are combined into multiple battery reference currents. In the above scheme, those skilled in the art can understand that there is a corresponding relationship between the current and the sampling value, and the sampling value can be used to represent the current situation.

[0058] In one embodiment, see Figure 3 The S50 obtains multiple battery currents of the energy management system, performs PID adjustment on the multiple battery currents and multiple battery reference currents, and outputs a PWM signal to achieve energy management, including: obtaining multiple battery currents of the energy management system, including a current sampling value BCA of battery A, a current sampling value BCB of battery B, and a current sampling value BCC of battery C; performing PID adjustment on a current reference sampling value BCRA of battery A, a current reference sampling value BCRB of battery B, a current reference sampling value BCRC of battery C, a current sampling value BCA of battery A, a current sampling value BCB of battery B, and a current sampling value BCC of battery C, and outputting a PWM signal to achieve energy management.

[0059] The above technical effects are: first, multiple energy storage inverters can quickly complete the grid-side forward and reverse power response in a short time; second, the accuracy of the EMS energy management system in controlling the forward and reverse power can be significantly improved; third, only one electric meter is used to realize the virtual reconstruction of the electric meters required for at least three energy storage inverters, thereby improving the efficiency of energy management and scheduling and reducing costs; third, when the SOC of batteries equipped with multiple energy storage inverters is inconsistent, SOC-based power redistribution can be realized to achieve uniform distribution of battery SOC in a shorter time.

[0060] After research, the inventor found that the load unit in the photovoltaic new energy scene includes two states. The first state is composed only of the user's household appliances, and the second state is composed of the inverter grid-connected system and household appliances. When the state of the load unit itself changes (for example, switching between the first state and the second state), the charge / discharge amount of the load unit will also change accordingly, and this scenario will bring technical problems: the inverter grid-connected system will charge, and the household appliances will use electricity. This state change is determined by the user at the load end. The state change process will affect the EMS energy management system, and its SOC power redistribution will take a long time. In order to solve the above problems, the solution proposed by the present invention can effectively shorten the time required for SOC to change from inconsistent values ​​to consistent values ​​when the state of the load unit itself changes.

[0061] In the above scheme, the specific meaning of the inverter power INPA of the energy storage inverter A corresponds to Inverter Power A, the specific meaning of the power state SOCA of the battery A corresponds to SOC A, the specific meaning of the inverter reference power INPRA of the energy storage inverter A corresponds to Inverter Power Ref A, the specific meaning of the allocated power MeterA of the energy storage inverter A corresponds to Meter A, the specific meaning of the compensation power ErrA of the energy storage inverter A corresponds to Error A, the specific meaning of the meter power MCA of the energy storage inverter A corresponds to Meter Comp A, the specific meaning of the battery power BPA of the battery A corresponds to Battery Power A, the specific meaning of the battery voltage BVA of the battery A corresponds to Battery Voltage A, the specific meaning of the battery reference power BPRA of the battery A corresponds to Battery Power Ref A, the specific meaning of the current reference sampling value BCRA of the battery A corresponds to Battery CurrentRef A, the specific meaning of the current sampling value BCA of the battery A corresponds to Battery Current A, and the specific meaning of the port meter power MP corresponds to Meter Power.

[0062] In one embodiment, the EMS energy management method is used for an energy management system in a grid-connected state; the energy management system executes the method as a control unit, and the SOC values ​​of multiple batteries in the energy management system are different from each other. Specifically, the state of charge SOCA of battery A is 80%, the state of charge SOCB of battery B is 30%, and the state of charge SOCC of battery C is 50%. According to the above conditions, it can be calculated that the total state of charge SOCT is 160%.

[0063] In addition, the inverter power INPA of module A, i.e. the first module, is equal to 1500w, the inverter power INPB of module B, i.e. the second module, is equal to 1000w, and the inverter power INPC of module C, i.e. the third module, is equal to 500w. By calculating the sum of the three, it can be found that the total inverter power INPT is 1500w plus 1000w plus 500w, which is equal to 3000w.

[0064] Under this condition, the total inverter power INPT is greater than 0 and is discharged to the load.

[0065] The inverter reference power INPRA of energy storage inverter A = 3000w × 80% ÷ 160% = 1500w.

[0066] The inverter reference power INPRB of energy storage inverter B = 3000w × 30% ÷ 160% = 562.5w.

[0067] The inverter reference power INPRC of the energy storage inverter C = 3000w × 50% ÷ 160% = 937.5w.

[0068] The compensation power of energy storage inverter A is ErrA=1500w–1500W=0w.

[0069] The compensation power of energy storage inverter B is ErrB=562.5w–1000w=-437.5w.

[0070] The compensation power of energy storage inverter C ErrC=937.5w–500w=437.5w.

[0071] When the proportional adjustment parameter Kp=0.5, the meter power MCA of energy storage inverter A=the compensation power ErrA×KP of energy storage inverter A=0w×0.5=0; the meter power MCB of energy storage inverter B=the compensation power ErrB×KP of energy storage inverter B=-437.5w×0.5=-218.75w; the meter power MCC of energy storage inverter C=the compensation power ErrC×KP of energy storage inverter C=-437.5w×0.5=218.75w.

[0072] Assuming that the electric meter is the grid flow load at this time, the port meter power MP = 500w, then since the sum of the meter powers allocated to module A, module B, and module C must be equal to the total meter power port meter power MP obtained, the power given to the three machines of module A, module B, and module C is as follows.

[0073] The meter power allocated to A: the allocated power of energy storage inverter A MeterA = (port meter power MP – meter power of energy storage inverter A MCA – meter power of energy storage inverter B MCB – meter power of energy storage inverter C MCC) ÷ 3 + allocated power of energy storage inverter C MeterCompA. From the above formula, the allocated power of energy storage inverter A MeterA = (500w – 0 + 218.75w – 218.75w) ÷ 3 + 0 = 166.6w.

[0074] The meter power allocated to B: the allocated power MeterB of energy storage inverter B = (port meter power MP – meter power MCA of energy storage inverter A – meter power MCB of energy storage inverter B – meter power MCC of energy storage inverter C) ÷ 3 + meter power MCB of energy storage inverter B. From the above formula, the allocated power MeterB of energy storage inverter B = (500w – 0 + 218.75w – 218.75w) ÷ 3 - 218.75w = -52.15w.

[0075] The meter power allocated to C: the allocated power MeterC of energy storage inverter C = (port meter power MP – meter power MCA of energy storage inverter A – meter power MCB of energy storage inverter B – meter power MCC of energy storage inverter C) ÷ 3 + meter power MCC of energy storage inverter C. From the above formula, the allocated power MeterC of energy storage inverter C = (500w – 0 + 218.75w – 218.75w) ÷ 3 + 218.75w = 385.35w.

[0076] At this time, the allocated power of energy storage inverter A is MeterA=166.6w, the allocated power of energy storage inverter B is MeterB=-52.15w, and the allocated power of energy storage inverter C is MeterC=385.35w; it can be seen that energy storage inverter A still needs to increase the discharge power to the load, energy storage inverter B still needs to reduce the discharge power, and energy storage inverter C needs to increase the discharge power to the load.

[0077] In one embodiment, the embodiment of the present invention further provides an energy management system, the energy management system includes a unit for executing the EMS energy management method as described in any of the above embodiments; the energy management system also includes a first module 10, a second module 20, a third module 30, an EMS control unit 1, an electric meter unit 2, a load unit 3, and a mains unit 4; the first module 10, the second module 20, the third module 30, the load unit 3, and the mains unit 4 are all connected to the electric meter unit 2; the EMS control unit 1 is connected to the first module 10, the second module 20, the third module 30, and the electric meter unit 2 via a 485 communication line. In one embodiment, the load unit 3 includes household appliances of the user and does not include an inverter grid-connected system; in another embodiment, the load unit 3 is composed of an inverter grid-connected system and household appliances.

[0078] The first module 10 of the energy management system includes a battery A and an energy storage inverter A connected to each other, the second module 20 includes a battery B and an energy storage inverter B connected to each other, and the third module 30 includes a battery C and an energy storage inverter C connected to each other; the energy storage inverter A, the energy storage inverter B, the energy storage inverter C, the load unit 3, and the mains unit 4 are all connected to the electric meter unit 2; the EMS control unit 1 is connected to the energy storage inverter A, the energy storage inverter B, the energy storage inverter C, and the electric meter unit 2 via a 485 communication line. The technical effect is that the energy management system can effectively shorten the time required for the SOC to change from inconsistent values ​​to consistent values ​​when the state of the load unit 3 itself changes.

[0079] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions, but such implementation should not be considered to be beyond the scope of the present invention.

[0080] The steps in the method of the embodiment of the present invention can be adjusted in order, combined and deleted according to actual needs. The units in the device of the embodiment of the present invention can be combined, divided and deleted according to actual needs. In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0081] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0082] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0083] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An EMS energy management method, characterized in that: The method is used for an energy management system in a grid-connected state; The energy management system includes a plurality of batteries and a plurality of energy storage inverters corresponding to the batteries one by one; The EMS energy management method comprises: S10, obtaining the power status of multiple batteries and the inverter power of multiple energy storage inverters; S20, determining whether the sum of the multiple inverter powers is greater than zero; S30, if the sum of the multiple inverter powers is greater than zero, obtaining the inverter reference powers of the multiple energy storage inverters during charging and discharging of the energy management system through the first calculation model and the multiple power states; S40, acquiring multiple battery reference powers and multiple battery reference currents according to multiple inverter reference powers; S50, obtaining multiple battery currents of the energy management system, performing PID adjustment on the multiple battery currents and multiple battery reference currents, and outputting PWM signals to realize energy management; Among them, S40 specifically includes: According to the inverter reference power of the energy storage inverter and the inverter power of the energy storage inverter, the difference between the two is used to obtain the compensation power of the energy storage inverter, which is then multiplied by the first coefficient for KP adjustment to obtain the meter power of the energy storage inverter; Obtaining the total power of the electric meter according to the sum of the electric meter powers of multiple energy storage inverters; The difference between the port meter power and the total meter power is divided by the number of energy storage inverters to obtain the virtual power of the energy management system. This is then added to the meter power of the energy storage inverter to obtain the allocated power of the energy storage inverter. Multiple energy storage inverters obtain battery power and battery voltage of multiple batteries; The battery power of the battery is added to the allocated power of the energy storage inverter, and then multiplied by the first coefficient to obtain the battery reference power of the battery; The battery reference power of the battery is divided by the battery voltage of the battery to obtain a current reference sampling value of the battery; and a plurality of current reference sampling values ​​are combined into a plurality of battery reference currents.

2. The EMS energy management method according to claim 1, characterized in that: Before the step S40 obtains a plurality of battery reference powers and a plurality of battery reference currents according to a plurality of inverter reference powers, the step includes: S31, if the sum of the multiple inverter powers is not greater than zero, obtain the inverter reference powers of the multiple energy storage inverters when the energy management system is charging and discharging through the second calculation model and multiple power states.

3. The EMS energy management method according to claim 2, characterized in that: The first module includes a battery A and an energy storage inverter A, the second module includes a battery B and an energy storage inverter B, and the third module includes a battery C and an energy storage inverter C; the S10 obtains the power status of multiple batteries and the inverter power of multiple energy storage inverters, including: Obtain three power states of three modules, including the power state SOCA of battery A, the power state SOCB of battery B, and the power state SOCC of battery C; The three inverter powers of the three modules are obtained, including the inverter power INPA of the energy storage inverter A, the inverter power INPB of the energy storage inverter B, and the inverter power INPC of the energy storage inverter C.

4. The EMS energy management method according to claim 3, characterized in that: The step S20 determines whether the sum of the multiple inverter powers is greater than zero, including: Calculate the inverter power INPA of energy storage inverter A, the inverter power INPB of energy storage inverter B, and the inverter power INPC of energy storage inverter C, and add the sum of the three to obtain the total inverter power INPT; It is determined whether the total inverter power INPT which is the sum of the three inverter powers is greater than zero.

5. The EMS energy management method according to claim 4, characterized in that: The total state of charge SOCT is equal to the sum of the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C; if the sum of the multiple inverter powers is greater than zero, the S30 obtains the inverter reference power of multiple energy storage inverters when the energy management system is charged and discharged through the first calculation model and the multiple power states, including: If the total inverter power INPT of the sum of the three inverter powers is greater than zero, the inverter discharges to the load, and the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C are substituted into the first calculation model to obtain three inverter reference powers when the energy management system is charged and discharged, including the inverter reference power INPRA of energy storage inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRC of energy storage inverter C; According to the first calculation model, the inverter reference power INPRA of the energy storage inverter A is equal to the total inverter power INPT multiplied by the state of charge SOCA of the battery A divided by the total state of charge SOCT; The inverter reference power INPRB of the energy storage inverter B is equal to the total inverter power INPT multiplied by the power state SOCB of the battery B divided by the total power state SOCT; The inverter reference power INPRC of the energy storage inverter C is equal to the total inverter power INPT multiplied by the state of charge SOCC of the battery C divided by the total state of charge SOCT.

6. The EMS energy management method according to claim 5, characterized in that: If the sum of the multiple inverter powers is not greater than zero, the S31 obtains the inverter reference powers of the multiple energy storage inverters during charging and discharging of the energy management system through the second calculation model and the multiple power states, including: If the total inverter power INPT of the sum of the three inverter powers is not greater than zero, the inverter discharges to the load, and the state of charge SOCA of battery A, the state of charge SOCB of battery B, and the state of charge SOCC of battery C are substituted into the second calculation model to obtain three inverter reference powers during charging and discharging of the energy management system, including the inverter reference power INPRA of energy storage inverter A, the inverter reference power INPRB of energy storage inverter B, and the inverter reference power INPRC of energy storage inverter C; According to the second calculation model, the inverter reference power INPRA of the energy storage inverter A is equal to the difference between 100% and the state of charge SOCA of the battery A, multiplied by the total inverter power INPT, divided by the total state of charge SOCT; The inverter reference power INPRB of the energy storage inverter B is equal to the difference between 100% and the state of charge SOCB of the battery B, multiplied by the total inverter power INPT, divided by the total state of charge SOCT; The inverter reference power INPRC of the energy storage inverter C is equal to the difference between 100% and the state of charge SOCC of the battery C, multiplied by the total inverter power INPT, divided by the total state of charge SOCT.

7. The EMS energy management method according to claim 6, characterized in that: The multiple meter powers include the meter power MCA of energy storage inverter A, the meter power MCB of energy storage inverter B, and the meter power MCC of energy storage inverter C; the multiple meter allocation powers include the allocation power MeterA of energy storage inverter A, the allocation power MeterB of energy storage inverter B, and the allocation power MeterC of energy storage inverter C; the port meter of the energy management system corresponds to the port meter power MP; The step S40 acquires a plurality of battery reference powers and a plurality of battery reference currents according to a plurality of inverter reference powers, including: According to the inverter reference power INPRA of the energy storage inverter A and the inverter power INPA of the energy storage inverter A, the difference between the two is used to obtain the compensation power ErrA of the energy storage inverter A, which is then multiplied by the first coefficient for KP adjustment to obtain the meter power MCA of the energy storage inverter A; According to the inverter reference power INPRB of the energy storage inverter B and the inverter power INPB of the energy storage inverter B, the difference between the two is used to obtain the compensation power ErrB of the energy storage inverter B, which is then multiplied by the first coefficient for KP adjustment to obtain the meter power MCB of the energy storage inverter B; According to the inverter reference power INPRC of the energy storage inverter C and the inverter power INPC of the energy storage inverter C, the difference between the two is used to obtain the compensation power ErrC of the energy storage inverter C, which is then multiplied by the first coefficient for KP adjustment to obtain the meter power MCC of the energy storage inverter C; The total meter power MCT is obtained by adding the meter power MCA of energy storage inverter A, the meter power MCB of energy storage inverter B, and the meter power MCC of energy storage inverter C. The difference between the port meter power MP and the meter total power MCT is divided by the value three to obtain the virtual power VP of the energy management system. Add the meter power MCA of the energy storage inverter A to obtain the allocated power MeterA of the energy storage inverter A. The difference between the port meter power MP and the meter total power MCT is divided by the value three to obtain the virtual power VP of the energy management system. Add the meter power MCB of the energy storage inverter A to obtain the allocated power MeterB of the energy storage inverter B. The difference between the port meter power MP and the meter total power MCT is divided by the value three to obtain the virtual power VP of the energy management system. Add the meter power MCC of the energy storage inverter A to obtain the allocated power MeterC of the energy storage inverter C. The three energy storage inverters obtain the battery power and battery voltage of the three batteries, including the battery power BPA of battery A, the battery power BPB of battery B, the battery power BPC of battery C, the battery voltage BVA of battery A, the battery voltage BVB of battery B, and the battery voltage BVC of battery C; The battery power BPA of battery A is added to the allocated power MeterA of energy storage inverter A, and then multiplied by the first coefficient to obtain the battery reference power BPRA of battery A; The battery power BPB of battery B is added to the allocated power MeterB of energy storage inverter B, and then multiplied by the first coefficient to obtain the battery reference power BPRB of battery B; The battery power BPC of battery C is added to the allocated power MeterC of energy storage inverter C, and then multiplied by the first coefficient to obtain the battery reference power BPRC of battery C; The battery reference power BPRA of battery A is divided by the battery voltage BVA of battery A to obtain the current reference sampling value BCRA of battery A; The battery reference power BPRB of the battery B is divided by the battery voltage BVB of the battery B to obtain the current reference sampling value BCRB of the battery B; The battery reference power BPRC of the battery C is divided by the battery voltage BVC of the battery C to obtain the current reference sampling value BCRC of the battery C; The battery reference power BPRA of battery A, the battery reference power BPRB of battery B, and the battery reference power BPRC of battery C are combined into multiple battery reference powers; The current reference sampling value BCRA of battery A, the current reference sampling value BCRB of battery B, and the current reference sampling value BCRC of battery C are combined into multiple battery reference currents.

8. The EMS energy management method according to claim 7, characterized in that: The S50 acquires multiple battery currents of the energy management system, performs PID adjustment on the multiple battery currents and multiple battery reference currents, and outputs PWM signals to realize energy management, including: Acquire multiple battery currents of the energy management system, including a current sampling value BCA of battery A, a current sampling value BCB of battery B, and a current sampling value BCC of battery C; PID adjustment is performed on the current reference sampling value BCRA of battery A, the current reference sampling value BCRB of battery B, the current reference sampling value BCRC of battery C, the current sampling value BCA of battery A, the current sampling value BCB of battery B, and the current sampling value BCC of battery C, and PWM signals are output to achieve energy management.

9. An energy management system, characterized in that: The energy management system comprises a unit for executing the EMS energy management method according to any one of claims 1 to 8; The energy management system further includes a first module, a second module, a third module, an EMS control unit, an electric meter unit, a load unit, and a mains unit; The first module, the second module, the third module, the load unit, and the mains unit are all connected to the electric meter unit; The EMS control unit is connected to the first module, the second module, the third module and the electric meter unit via a 485 communication line.

10. The energy management system according to claim 9, characterized in that: The first module of the energy management system includes a battery A and an energy storage inverter A connected to each other, the second module includes a battery B and an energy storage inverter B connected to each other, and the third module includes a battery C and an energy storage inverter C connected to each other; The energy storage inverter A, the energy storage inverter B, the energy storage inverter C, the load unit, and the mains unit are all connected to the electric meter unit; The EMS control unit is connected to the energy storage inverter A, the energy storage inverter B, the energy storage inverter C, and the electric meter unit via a 485 communication line.

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