On-load control method of split-phase converter with single-phase bypass input

Abstract

The invention discloses an on-load control method for a split-phase converter with single-phase bypass input, and the method comprises the steps: carrying out the adjustment of the AC output voltage of a first inversion module based on the commercial power voltage, the actual DC bus voltage, and the first AC output voltage and first AC output current of the first inversion module in the split-phase converter, the first alternating-current output voltage of the first inversion module is kept at the split-phase voltage; and based on the commercial power phase angle, the actual DC bus voltage, and a second AC output voltage and a second AC output current of a second inversion module in the split-phase converter, the AC output current of the second inversion module is adjusted, so that the power of the second split-phase load is balanced with the power of the first split-phase load. The split-phase voltage is constructed under the condition that the single-phase mains supply is input into the split-phase converter, and the split-phase two-phase voltage balance can be maintained even under the working condition of unbalanced split-phase load.

Description

Technical Field

[0001] The present invention relates to the technical field of split-phase converters, and in particular to a load control method for a split-phase converter with a single-phase bypass input. Background Art

[0002] The energy storage converter is the core component of the energy storage system. It can realize the charging and discharging process of the energy storage system and perform AC-DC conversion. Specifically, the energy storage converter can convert the DC power of the energy storage system into AC power and transmit it to the power grid or use it for AC loads; it can also rectify the AC power of the power grid into DC power to charge the energy storage system. This equipment is widely used in many fields.

[0003] Household energy storage converters can optimize household electricity management and improve household power supply reliability. They have become increasingly popular in recent years. Split-phase converters are a common type of household energy storage converters. They use a split-phase topology to split the AC signal into two signals with a phase difference of 180 degrees. The separated signals are connected to the loads separately. Figure 1 This type of topology usually encounters problems: when the system mains is input in single-phase, split-phase loads, especially unbalanced loads, cannot be connected. Since two loads are equivalently connected in series in a single-phase mains circuit, if the power of the two-phase loads is unbalanced, it will lead to uneven voltage division between the two phases. When the power is seriously unbalanced, it will cause overvoltage damage or undervoltage damage to the load. The solution at this time is usually:

[0004] 1. Detect the voltage at the split-phase port. When overvoltage or undervoltage is detected, the system protection disconnects the AC power supply.

[0005] 2. Application requirements stipulate that when single-phase AC power is connected, split-phase loads are not allowed.

[0006] In summary, the split-phase converter cannot achieve single-phase mains access during use and carries an unbalanced split-phase load. Summary of the invention

[0007] In view of this, the present invention provides a load control method for a split-phase converter with a single-phase bypass input, the main purpose of which is to solve the problem that the existing split-phase converter cannot achieve single-phase mains access when in use and carries an unbalanced split-phase load.

[0008] According to one aspect of the present application, a method for controlling a split-phase converter with a single-phase bypass input is provided, which is applied to a load circuit of the split-phase converter. The method comprises:

[0009] Obtain the mains voltage, mains phase angle, actual DC bus voltage of the DC power supply connected to the split-phase converter, and the first AC output voltage, first AC output current, second AC output voltage and second AC output current of the first inverter module in the split-phase converter, wherein both ends of the first AC output voltage are connected to a first split-phase load, and both ends of the second AC output voltage are connected to a second split-phase load;

[0010] Based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current, adjusting the first AC output voltage of the first inverter module so that the first AC output voltage of the first inverter module is maintained at a split-phase voltage;

[0011] Based on the AC power phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current, the second AC output current of the second inverter module is adjusted so that the power of the second split-phase load is balanced with the power of the first split-phase load.

[0012] Optionally, the adjusting the AC output voltage of the first inverter module based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current includes:

[0013] Based on the mains voltage and the first AC output voltage, adjusting a first voltage loop corresponding to the first inverter module to obtain a first regulated voltage;

[0014] Based on the first regulating voltage and the first AC output current, regulating a first current loop corresponding to the first inverter module to obtain a first regulating current;

[0015] taking the sum of the first regulated current and the first AC output voltage as a first intermediate regulated value;

[0016] Based on the ratio of the first intermediate adjustment value to the actual DC bus voltage, a first PWM signal corresponding to the first inverter module is determined, wherein the first inverter module adjusts the first AC output voltage according to the first PWM signal.

[0017] Optionally, the adjusting a first voltage loop corresponding to the first inverter module based on the mains voltage and the first AC output voltage to obtain a first regulated voltage includes:

[0018] Using half of the mains voltage as a given value of a first voltage loop corresponding to the first inverter module, and using the first AC output voltage as a feedback value of the first voltage loop;

[0019] Taking the difference between the given value and the feedback value of the first voltage loop as the first voltage deviation;

[0020] The first voltage deviation is input into a voltage controller in the first voltage loop to obtain a first regulated voltage.

[0021] Optionally, the adjusting a first current loop corresponding to the first inverter module based on the first adjustment voltage and the first AC output current to obtain a first adjustment current includes:

[0022] Using the first regulating voltage as a given value of a first current loop corresponding to the first inverter module, and using the first AC output current as a feedback value of the first current loop;

[0023] Taking the difference between the given value and the feedback value of the first current loop as the first current deviation;

[0024] The first current deviation is input into a current controller in the first current loop to obtain a first regulating current.

[0025] Optionally, the adjusting the AC output current of the second inverter module based on the mains phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current includes:

[0026] Based on a preset DC bus voltage and the actual DC bus voltage, adjusting a second voltage loop corresponding to the second inverter module to obtain a second regulated voltage;

[0027] Based on the second regulated voltage, the mains phase angle and the second AC output current, regulating the second current loop corresponding to the second inverter module to obtain a second regulated current;

[0028] taking the sum of the second regulated current and the second AC output voltage as a second intermediate regulated value;

[0029] Based on the ratio of the second intermediate adjustment value to the actual DC bus voltage, a second PWM signal corresponding to the second inverter module is determined, wherein the second inverter module adjusts the second AC output current according to the second PWM signal.

[0030] Optionally, the adjusting a second voltage loop corresponding to the second inverter module based on a preset DC bus voltage and the actual DC bus voltage to obtain a second regulated voltage includes:

[0031] Using the preset DC bus voltage as a given value of a second voltage loop corresponding to the second inverter module, and using the actual DC bus voltage as a feedback value of the second voltage loop;

[0032] Taking the difference between the given value and the feedback value of the second voltage loop as the second voltage deviation;

[0033] The second voltage deviation is input into a voltage controller in the second voltage loop to obtain a second regulated voltage.

[0034] Optionally, based on the second regulated voltage, the mains phase angle and the second AC output current, regulating the second current loop corresponding to the second inverter module to obtain the second regulated current includes:

[0035] Using the product of the second regulated voltage and the sine value of the mains phase angle as a given value of a second current loop corresponding to the second inverter module, and using the second AC output current as a feedback value of the second current loop;

[0036] Taking the difference between the given value and the feedback value of the second current loop as the second current deviation;

[0037] The second current deviation is input into a current controller in the second current loop to obtain a second regulating current.

[0038] Optionally, the current controller of the first inverter module, the current controller of the second inverter module and the voltage controller of the first inverter module are PID controllers, PI controllers or PR controllers.

[0039] Optionally, the voltage controller of the second inverter module is a PID controller or a PI controller.

[0040] By means of the above technical solution, the technical solution provided by the embodiment of the present invention has at least the following advantages:

[0041] The present application provides a load control method for a split-phase converter with a single-phase bypass input, which adjusts the AC output voltage of the first inverter module of the split-phase converter so that the first inverter module serves as a voltage source and the AC output voltage of the first inverter module is maintained at the split-phase voltage, and adjusts the AC output current of the second inverter module of the split-phase converter so that the second inverter module inputs current to or extracts current from the second load, thereby balancing the power of the first load and the power of the second load, thereby achieving a split-phase voltage when the split-phase converter is input with a single-phase mains power supply, and maintaining a split-phase two-phase voltage balance even under the condition of an unbalanced split-phase load.

[0042] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0044] Figure 1 A load circuit connection diagram of a split-phase converter with a single-phase bypass input provided in an embodiment of the present application is shown;

[0045] Figure 2 A flow chart showing a method for load control of a split-phase converter with a single-phase bypass input provided in an embodiment of the present application is shown;

[0046] Figure 3 A topological diagram of an inverter module of a split-phase converter provided in an embodiment of the present application is shown;

[0047] Figure 4 A schematic diagram showing the AC output voltage regulation of the first inverter module of a load control method for a split-phase converter with a single-phase bypass input provided in an embodiment of the present application is shown;

[0048] Figure 5 A schematic diagram showing the AC output current regulation by the second inverter module of a load control method for a split-phase converter with a single-phase bypass input provided by an embodiment of the present application is shown;

[0049] in,

[0050] In the figure: Vbus-actual DC bus voltage; Vo1-first AC output voltage; IL1-first AC output current; Vo2-second AC output voltage; IL2-second AC output current; Vg-mains voltage; θ-mains phase angle; Load1-first load; Load2-second load; MCU-controller; Module1-first inverter module; Module2-second inverter module; Vo1Ref-given value of the first voltage loop; Vo1fdb-feedback value of the first voltage loop; Gv1-voltage controller in the first voltage loop; iL1fdb-feedback value of the first current loop; Gi1-current controller in the first current loop; VbusRef-given value of the second voltage loop; Vbusfdb-feedback value of the second voltage loop; Gv2-voltage controller in the second voltage loop; iL2fdb-feedback value of the second current loop; Gi2-current controller in the second current loop. DETAILED DESCRIPTION

[0051] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0052] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0053] In view of the problem that the existing split-phase converter cannot realize single-phase mains access when in use and has unbalanced split-phase load, the embodiment of the present application provides a load control method for a split-phase converter with a single-phase bypass input, such as Figure 2 As shown, the method includes:

[0054] 102: Obtain the mains voltage, mains phase angle, actual DC bus voltage of the DC power supply connected to the split-phase converter, and the first AC output voltage, first AC output current of the first inverter module, and the second AC output voltage and second AC output current of the second inverter module in the split-phase converter, wherein both ends of the first AC output voltage are connected to a first split-phase load, and both ends of the second AC output voltage are connected to a second split-phase load;

[0055] 104: adjusting the AC output voltage of the first inverter module based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current, so that the first AC output voltage of the first inverter module is maintained at the split-phase voltage;

[0056] 106: Based on the AC phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current, the AC output current of the second inverter module is adjusted so that the power of the second split-phase load is balanced with the power of the first split-phase load.

[0057] Split-phase inverter is also called split-phase converter. Figure 1 As shown, the first load Load1 and the second load Load1 are connected in series in the single-phase power grid of the AC power supply. At the same time, the output ends L1 and N of an inverter module in the split-phase converter are connected at both ends of the first load, and the output ends L2 and N of another inverter module in the split-phase converter are connected at both ends of the second load.

[0058] The split-phase converter includes a DC / DC energy storage battery, two inverter modules and a controller MCU, one of which is called the first inverter module Module 1 and the other is called the second inverter module Module 2. The topology of the inverter module can be a half-bridge, such as Figure 3 As shown, it can also be a common DC / AC bidirectional conversion topology such as full bridge, three-level, etc. The DC buses of the DC input ports of the inverter modules are connected in parallel.

[0059] The input port connection of the DC / DC direct current energy storage battery can be connected in various forms: 1) the battery is directly connected to the DC bus; 2) the battery is connected to the DC bus through a DCDC module.

[0060] The output end of the energy storage battery is connected to the DC bus, which is respectively connected to the DC input end of the first inverter module and the DC input end of the second inverter module. The first output end of the controller is connected to the PWM signal input end of the first inverter module, and the second output end of the controller MCU is connected to the PWM signal input end of the second inverter module. A bus voltage acquisition module is arranged between the two output ends BUS+ and BUS- of the DC bus to collect the DC bus voltage Vbus; a first AC output voltage acquisition module is arranged between the L1 output end and the N output end of the first inverter module to collect the first AC output voltage of the first inverter module; a first AC current acquisition module is arranged between the L1 output end and the first load of the first inverter module to collect the first AC output current of the first inverter module; a second AC output voltage acquisition module is arranged between the L2 output end and the N output end of the second inverter module to collect the second AC output voltage of the second inverter module; a second AC current acquisition module is arranged between the L2 output end and the second load of the second inverter module to collect the second AC output current of the second inverter module.

[0061] The mains voltage Vg collected by the mains voltage collection module is sent to the controller, the mains phase angle θ obtained by the PLL phase-locked loop is sent to the controller, the actual DC bus voltage Vbus collected by the bus voltage collection module is sent to the controller, the first AC output voltage of the first inverter module collected by the first AC output voltage collection module is sent to the controller, the first AC output current of the first inverter module collected by the first AC current collection module is sent to the controller, the second AC output voltage of the second inverter module collected by the second AC output voltage collection module is sent to the controller, and the second AC output current of the second inverter module collected by the second AC current collection module is sent to the controller.

[0062] The execution subject of the present application is a controller in a split-phase converter. The controller sequentially performs outer-loop voltage closed-loop control and inner-loop current closed-loop control on the first inverter module in the split-phase converter based on the mains voltage, the actual DC bus voltage, the first AC output voltage and the first AC output current, so as to adjust the AC output voltage of the first inverter module, so that the first inverter module acts as a voltage source, and the first AC output voltage of the first inverter module is maintained at the split-phase voltage, and the split-phase voltage is 110V. The controller sequentially performs outer-loop voltage closed-loop control and inner-loop current closed-loop control on the second inverter module in the split-phase converter based on the mains phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current, so as to adjust the AC output current of the second inverter module, so that the second inverter module acts as a current source, adjusts the AC output current of the second inverter module, and adjusts the current flowing through the second load, so as to keep the power of the second load balanced with the power of the first load.

[0063] For example, when the first load and the second load are loads with different equivalent resistance values, since the first load and the second load are connected in series, according to the method of the prior art, the current values ​​flowing through the first load and the second load are the same. Since the equivalent resistance values ​​are different, the voltage across the first load and the voltage across the second load are different, and the split-phase voltage cannot be constructed. At this time, the power of the two loads is unbalanced. Using the control method of the present application, the AC output voltage of the first inverter module is adjusted when the power is unbalanced. The first AC output voltage of the first inverter module is maintained at the split-phase voltage, and the second AC voltage of the second inverter module is also maintained at the split-phase voltage. Since the equivalent resistance values ​​of the two loads are different, the voltage values ​​across the two loads are the same. If the power of the two loads is the same, the current flowing through the two loads must be different. Therefore, the AC output current of the second inverter module is adjusted. Since the output end of the second inverter module is connected to the second load, the current flowing through the second load is adjusted through the second AC output current of the second inverter module so that the power of the two loads is the same.

[0064] In one embodiment, the AC output current of the first inverter module is adjusted so that the first inverter module acts as a current source, and the AC output voltage of the second inverter module is adjusted so that the second inverter module acts as a voltage source.

[0065] Compared with the prior art, the load control method of the split-phase converter with single-phase bypass input of the present application adjusts the AC output voltage of the first inverter module so that the first inverter module acts as a voltage source and the AC output voltage of the first inverter module is maintained at the split-phase voltage, and the AC output current of the second inverter module is adjusted so that the second inverter module inputs or extracts current to the second load, so that the power of the first load and the power of the second load are balanced, thereby realizing the construction of a split-phase voltage in the case of a single-phase AC power input split-phase converter, and maintaining the balance of the split-phase two-phase voltage even under the condition of an unbalanced split-phase load.

[0066] In one embodiment, adjusting the AC output voltage of the first inverter module based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current includes:

[0067] Based on the mains voltage and the first AC output voltage, adjusting the first voltage loop corresponding to the first inverter module to obtain a first regulated voltage;

[0068] Based on the first regulation voltage and the first AC output current, a first current loop corresponding to the first inverter module is regulated to obtain a first regulation current;

[0069] taking the sum of the first regulated current and the first AC output voltage as a first intermediate regulated value;

[0070] Based on the ratio of the first intermediate adjustment value to the actual DC bus voltage, a first PWM signal corresponding to the first inverter module is determined, wherein the first inverter module adjusts the first AC output voltage according to the first PWM signal.

[0071] Specifically, firstly, an outer loop voltage closed-loop control (i.e., the first voltage loop) is performed on the first inverter module to obtain a first regulated voltage, and on the basis of the outer loop voltage closed-loop control, an inner loop current closed-loop control (the first current loop) is performed on the first inverter module to obtain a first regulated current, and the sum of the first regulated current and the first AC output voltage is used as a first intermediate regulated value, and the first intermediate regulated value is normalized, specifically, the ratio of the first intermediate regulated value to the actual DC bus voltage is determined, and the ratio is used as a first PWM signal corresponding to the first inverter module, so that the first inverter module adjusts the first AC output voltage according to the first PWM signal.

[0072] In one embodiment, based on the mains voltage and the first AC output voltage, adjusting the first voltage loop corresponding to the first inverter module to obtain the first regulated voltage includes:

[0073] Using half of the mains voltage as a given value of a first voltage loop corresponding to the first inverter module, and using the first AC output voltage as a feedback value of the first voltage loop;

[0074] Taking the difference between the given value and the feedback value of the first voltage loop as the first voltage deviation;

[0075] The first voltage deviation is input to a voltage controller in the first voltage loop to obtain a first regulated voltage.

[0076] In this embodiment, if Figure 4 As shown, the mains voltage Vg / 2 is used as the given value Vo1Ref (Vo1Ref=Vg / 2) of the first voltage loop of the first inverter module Module1; the first AC output voltage Vo1 of the first inverter module Module1 is used as the feedback value of the first voltage loop (Vo1fdb=Vo1), and the voltage closed-loop control is implemented through the voltage controller Gv1 in the first voltage loop to obtain the first regulated voltage, and the obtained first regulated voltage is used as the given value of the first current loop.

[0077] In one embodiment of the present invention, based on the first regulation voltage and the first AC output current, regulating the first current loop corresponding to the first inverter module to obtain the first regulation current includes:

[0078] Using the first regulated voltage as a given value of a first current loop corresponding to the first inverter module, and using the first AC output current as a feedback value of the first current loop;

[0079] Taking the difference between the given value and the feedback value of the first current loop as the first current deviation;

[0080] The first current deviation is input into a current controller in the first current loop to obtain a first regulating current.

[0081] Specifically, Figure 4 As shown, the first regulating voltage is used as the given value of the first current loop of the first inverter module, and the first AC output current of the first inverter module is used as the feedback value of the first current loop (iL1fdb=IL1). The current closed-loop control is performed by the current controller Gi1 in the first current loop to obtain the first regulating current. The sum of the obtained first regulating current and the AC output voltage of the first inverter module is used as the first intermediate regulating value. According to the ratio of the first intermediate regulating value to the actual bus DC voltage, the PWM signal is determined, and the drive signal PWM1 of the first inverter module is output to the first inverter module.

[0082] In one embodiment, adjusting the AC output current of the second inverter module based on the mains phase angle, the actual DC bus voltage, the second AC output voltage, and the second AC output current includes:

[0083] Based on the preset DC bus voltage and the actual DC bus voltage, adjusting the second voltage loop corresponding to the second inverter module to obtain a second regulated voltage;

[0084] Based on the second regulated voltage, the mains phase angle and the second AC output current, a second current loop corresponding to the second inverter module is regulated to obtain a second regulated current;

[0085] taking the sum of the second regulated current and the second AC output voltage as a second intermediate regulated value;

[0086] Based on the ratio of the intermediate adjustment value to the actual DC bus voltage, a second PWM signal corresponding to the second inverter module is determined, wherein the second inverter module adjusts the second AC output current according to the second PWM signal.

[0087] In this embodiment, specifically, firstly, an outer loop voltage closed-loop control (i.e., a first voltage loop) is performed on the second inverter module to obtain a second regulated voltage, and on the basis of the outer loop voltage closed-loop control, an inner loop current closed-loop control (a second current loop) is performed on the second inverter module to obtain a second regulated current, and the sum of the second regulated current and the second AC output voltage is used as a second intermediate regulated value, and the second intermediate regulated value is normalized, specifically, a ratio of the second intermediate regulated value to the actual DC bus voltage is determined, and the ratio is used as a second PWM signal corresponding to the second inverter module, so that the second inverter module regulates the second AC output current according to the second PWM signal.

[0088] In one embodiment, based on a preset DC bus voltage and an actual DC bus voltage, adjusting a second voltage loop corresponding to a second inverter module to obtain a second regulated voltage includes:

[0089] Using the preset DC bus voltage as a given value of a second voltage loop corresponding to the second inverter module, and using the actual DC bus voltage as a feedback value of the second voltage loop;

[0090] The difference between the given value and the feedback value of the second voltage loop is used as the second voltage deviation;

[0091] The second voltage deviation is input to a voltage controller in a second voltage loop to obtain a second regulated voltage.

[0092] In this embodiment, Figure 5 As shown, the preset DC bus voltage is used as the given value VbusRef of the second voltage loop of the second inverter module Module1; the actual DC bus voltage is used as the feedback value of the second voltage loop (Vbusfdb=Vbus), and the voltage closed-loop control is implemented through the voltage controller Gv2 in the second voltage loop to obtain the second regulated voltage Gv2out.

[0093] In one embodiment, based on the second regulated voltage, the mains phase angle and the second AC output current, the second current loop corresponding to the second inverter module is regulated to obtain the second regulated current, including:

[0094] The product of the second regulated voltage and the sine value of the mains phase angle is used as a given value of a second current loop corresponding to the second inverter module, and the second AC output current is used as a feedback value of the second current loop;

[0095] The difference between the given value and the feedback value of the second current loop is used as the second current deviation;

[0096] The second current deviation is input into a current controller in the second current loop to obtain a second regulating current.

[0097] Specifically, Figure 5 As shown, the product of the second regulating voltage Gv2out and the sine value of the mains phase angle θ is used as the given value ILref=Gv2out*Sinθ of the second current loop of the second inverter module, and the second AC output current of the second inverter module is used as the feedback value of the second current loop (iL2fdb=IL2). The current closed-loop control is performed by the current controller Gi2 in the second current loop to obtain the second regulating current. The sum of the obtained second regulating current and the AC output voltage of the second inverter module (Vo2fdb=Vo2) is used as the second intermediate regulating value. According to the ratio of the second intermediate regulating value to the actual bus DC voltage, the second PWM signal is determined, and the drive signal PWM of the second inverter module is output to the second inverter module.

[0098] In one embodiment, the current controller of the first inverter module, the current controller of the second inverter module and the voltage controller of the first inverter module are traditional controllers, such as PID controller, PI controller or PR controller.

[0099] Specifically, the voltage controller and the current controller of the first inverter module and the current controller of the second inverter module are all common controllers, such as a PID controller, a PR controller, a PR controller, and the like.

[0100] In one embodiment, the voltage controller of the second inverter module is a PID controller or a PI controller.

[0101] Specifically, the voltage controller of the second inverter module must be a controller with an integrator or a controller similar to an integrator, such as a PID controller, a PI controller, and the like.

[0102] The output upper and lower limits of the voltage controller of the second inverter module are

[0103] P1 is the sampled active power of the first inverter module: it can be calculated through the first AC output voltage and the first AC output current of the first inverter module.

[0104] Pchg is the battery charge / discharge power. The Pchg power can be scheduled or preset by the host computer. Pchg>0 can be set for charging, and Pchg<0 for discharging.

[0105] This limit value is used to control the charging power of the battery port. If the system has no battery or the charging power is set to neither charge nor discharge, set Pchg = 0.

[0106] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices. In one embodiment, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0107] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A load control method for a split-phase converter with a single-phase bypass input, applied to a load circuit of a split-phase converter, characterized in that: include: Obtain the mains voltage, mains phase angle, actual DC bus voltage of the DC power supply connected to the split-phase converter, and the first AC output voltage, first AC output current, second AC output voltage and second AC output current of the first inverter module in the split-phase converter, wherein both ends of the first AC output voltage are connected to a first split-phase load, and both ends of the second AC output voltage are connected to a second split-phase load; Based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current, adjusting the first AC output voltage of the first inverter module so that the first AC output voltage of the first inverter module is maintained at a split-phase voltage; Based on the AC power phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current, the second AC output current of the second inverter module is adjusted so that the power of the second split-phase load is balanced with the power of the first split-phase load.

2. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 1, characterized in that: The adjusting the AC output voltage of the first inverter module based on the mains voltage, the actual DC bus voltage, the first AC output voltage, and the first AC output current includes: Based on the mains voltage and the first AC output voltage, adjusting a first voltage loop corresponding to the first inverter module to obtain a first regulated voltage; Based on the first regulating voltage and the first AC output current, regulating a first current loop corresponding to the first inverter module to obtain a first regulating current; taking the sum of the first regulated current and the first AC output voltage as a first intermediate regulated value; Based on the ratio of the first intermediate adjustment value to the actual DC bus voltage, a first PWM signal corresponding to the first inverter module is determined, wherein the first inverter module adjusts the first AC output voltage according to the first PWM signal.

3. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 2, characterized in that: The step of adjusting a first voltage loop corresponding to the first inverter module based on the mains voltage and the first AC output voltage to obtain a first regulated voltage includes: Using half of the mains voltage as a given value of a first voltage loop corresponding to the first inverter module, and using the first AC output voltage as a feedback value of the first voltage loop; Taking the difference between the given value and the feedback value of the first voltage loop as the first voltage deviation; The first voltage deviation is input into a voltage controller in the first voltage loop to obtain a first regulated voltage.

4. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 3, characterized in that: The step of adjusting the first current loop corresponding to the first inverter module based on the first adjustment voltage and the first AC output current to obtain the first adjustment current includes: Using the first regulating voltage as a given value of a first current loop corresponding to the first inverter module, and using the first AC output current as a feedback value of the first current loop; Taking the difference between the given value and the feedback value of the first current loop as the first current deviation; The first current deviation is input into a current controller in the first current loop to obtain a first regulating current.

5. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 1, characterized in that: The adjusting the AC output current of the second inverter module based on the mains phase angle, the actual DC bus voltage, the second AC output voltage and the second AC output current includes: Based on a preset DC bus voltage and the actual DC bus voltage, adjusting a second voltage loop corresponding to the second inverter module to obtain a second regulated voltage; Based on the second regulated voltage, the mains phase angle and the second AC output current, regulating the second current loop corresponding to the second inverter module to obtain a second regulated current; taking the sum of the second regulated current and the second AC output voltage as a second intermediate regulated value; Based on the ratio of the second intermediate adjustment value to the actual DC bus voltage, a second PWM signal corresponding to the second inverter module is determined, wherein the second inverter module adjusts the second AC output current according to the second PWM signal.

6. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 5, characterized in that: The step of adjusting the second voltage loop corresponding to the second inverter module based on the preset DC bus voltage and the actual DC bus voltage to obtain a second regulated voltage includes: Using the preset DC bus voltage as a given value of a second voltage loop corresponding to the second inverter module, and using the actual DC bus voltage as a feedback value of the second voltage loop; Taking the difference between the given value and the feedback value of the second voltage loop as the second voltage deviation; The second voltage deviation is input into a voltage controller in the second voltage loop to obtain a second regulated voltage.

7. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 5, characterized in that: The step of adjusting the second current loop corresponding to the second inverter module based on the second regulated voltage, the mains phase angle and the second AC output current to obtain the second regulated current includes: Using the product of the second regulated voltage and the sine value of the mains phase angle as a given value of a second current loop corresponding to the second inverter module, and using the second AC output current as a feedback value of the second current loop; Taking the difference between the given value and the feedback value of the second current loop as the second current deviation; The second current deviation is input into a current controller in the second current loop to obtain a second regulating current.

8. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 4 or 7, characterized in that: The current controller is a PID controller, a PI controller or a PR controller.

9. The load control method of a split-phase converter with single-phase bypass input as claimed in claim 6, characterized in that: The voltage controller is a PID controller or a PI controller.

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