Demand response enablement device switch state detection circuit, method, and inverter

Abstract

The application discloses a switch state detection circuit and method of a demand response enabling device and an inverter, and relates to the technical field of electronic power, and the switch state detection circuit comprises a control unit and a selection unit; the selection unit comprises one common end and a plurality of selection ends; wherein each demand response mode port is connected with a selection end, and the common end is connected with the control unit; the control unit is used for controlling the selection unit to turn on the common end and one selection end, acquiring a common end voltage, and determining the switch state of the switch corresponding to the demand response mode port connected with the selection end according to the common end voltage. The application can avoid mutual influence between switch branch switch states when detecting the switch state, and improve the accuracy of the detection result.

Description

Technical Field

[0001] This invention relates to the field of electronic power technology, and in particular to a switch state detection circuit, method, and inverter for a demand response enabling device. Background Technology

[0002] With the rapid development of new energy power generation technologies, inverters, as the core equipment between new energy power generation systems and the power grid, directly affect the stability, security, and energy utilization efficiency of the power grid. To adapt to the dispatching needs of smart grids, achieve power grid supply and demand balance, and improve power quality, Demand Response Modes (DRM) are widely used in inverters.

[0003] In practical applications, inverters transmit commands through a Demand Response Enabling Device (DRED) to control their input and output power. Specifically, the DRED includes switches S0-S9 and S1a, S5a, etc. By controlling the closing and opening of these switches, different DRED modes are created, and the switch states are fed back to the inverter, enabling the inverter to regulate its input and output power. Therefore, the inverter needs to effectively detect and identify the various switch states of the DRED and convert these signals into corresponding operating control commands. This allows for coordinated scheduling between the inverter and the power grid, ensuring the stability and security of the power grid operation.

[0004] In existing technologies, the inverter detects the various switching states of the DRED by applying voltage to each switching branch of the DRED and determining the switching state of each branch by detecting the voltage division state. However, since the DRED has multiple switching branches, and these branches converge to the same common connection point when the switches are closed, detecting the switching state of one switching branch is affected by the switching states of other switching branches. This alters the voltage division state of that switching branch, leading to inaccurate detection results. Consequently, coordinated scheduling between the inverter and the grid cannot be achieved, and the stability and security of grid operation cannot be guaranteed. Summary of the Invention

[0005] This invention provides a switch state detection circuit for a demand response enabler, used to avoid mutual interference between the switch states of different switch branches when detecting switch states, improve the accuracy of detection results, and thereby achieve coordinated scheduling between the inverter and the power grid, ensuring the stability and security of power grid operation. The switch state detection circuit is used to detect the switch states of each switch in the demand response enabler. The demand response enabler includes multiple demand response mode ports, and the switch state detection circuit includes a control unit and a selection unit; the selection unit includes a common terminal and multiple selection terminals. Each demand response mode port is connected to a selection port, and the common port is connected to the control unit. The control unit is used to control the selection unit to connect the common terminal to one of the selection terminals, obtain the voltage of the common terminal, and determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal based on the voltage of the common terminal.

[0006] Optionally, the selection unit includes a multiplexer, which includes a common terminal and multiple selection terminals.

[0007] Optionally, the selection unit includes multiple selection switches, the first ends of the multiple selection switches are interconnected as a common terminal, and the second end of each selection switch serves as a selection terminal of the selection unit.

[0008] Optionally, the multiple selection terminals include a first selection terminal, a second selection terminal, a third selection terminal, a fourth selection terminal, and a fifth selection terminal; The first selection terminal is connected to the first demand response mode port, and the first demand response mode port is connected to the ninth switch and the tenth switch. The second selection terminal is connected to the second demand response mode port, and the second demand response mode port is connected to the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch; The third selection terminal is connected to the third demand response mode port, and the third demand response mode port is connected to the second switch and the sixth switch; The fourth selection terminal is connected to the fourth demand response mode port, and the fourth demand response mode port is connected to the third switch and the seventh switch; The fifth selection terminal is connected to the fifth demand response mode port, and the fifth demand response mode port is connected to the fourth switch and the eighth switch.

[0009] Optionally, the control unit is used for: The control selection unit connects the common terminal to the first selection terminal and obtains the voltage of the common terminal. Based on the voltage of the common terminal, it determines the switching state of the ninth switch and the tenth switch. Alternatively, the control selection unit connects the common terminal to the second selection terminal and obtains the voltage of the common terminal. Based on the voltage of the common terminal, it determines the switching states of the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch. Alternatively, the control selection unit can connect the common terminal to the third selection terminal and obtain the voltage of the common terminal, and determine the switching state of the second and sixth switches based on the voltage of the common terminal. Alternatively, the control selection unit can connect the common terminal to the fourth selection terminal and obtain the voltage of the common terminal, and determine the switching state of the third switch and the seventh switch based on the voltage of the common terminal. Alternatively, the control selection unit can connect the common terminal to the fifth selection terminal and obtain the voltage of the common terminal, and determine the switching state of the fourth and eighth switches based on the voltage of the common terminal.

[0010] Optionally, the switch status detection circuit also includes a voltage divider resistor and a power supply; the selection unit also includes a ground terminal; The two ends of the voltage divider resistor are respectively connected to the power supply and the common terminal of the selection unit, and the ground terminal of the selection unit is connected to the reference ground port of the demand response enable device. Alternatively, the two ends of the voltage divider resistor are connected to the common terminal and the ground terminal of the selection unit, respectively, and the power supply is connected to the reference ground port of the demand response enable device.

[0011] This invention also provides a method for detecting the switch status of a demand response enabling device, used to avoid mutual interference between the switch statuses of different switch branches when detecting the switch status, improve the accuracy of the detection results, and thereby achieve coordinated scheduling between the inverter and the power grid, ensuring the stability and security of the power grid operation; the method includes: When the common terminal of the selection unit is connected to any one of the selection terminals, obtain the common terminal voltage; Based on the common terminal voltage, determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal.

[0012] Optionally, based on the common terminal voltage, the switching state of the switch corresponding to the demand response mode port connected to the selection terminal is determined, including: When the common terminal of the selection unit is connected to the first selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the ninth switch is in the open state. If the common terminal voltage meets the preset second voltage condition, then the ninth switch is closed and the tenth switch is closed. If the common terminal voltage does not meet the preset first voltage condition and the preset second voltage condition, then the ninth switch is closed and the tenth switch is open. Based on the common terminal voltage, the resistance value of the demand response mode detection resistor is determined, and based on the preset resistance threshold range of the resistance value, the control state of the demand response enabling device is determined.

[0013] Optionally, based on the common terminal voltage, the switching state of the switch corresponding to the demand response mode port connected to the selection terminal is determined, including the condition that the ninth switch is in the closed state and the tenth switch is in the open state: When the common terminal of the selection unit is connected to the second selection terminal, if the voltage of the common terminal meets the preset first voltage condition, then the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset third voltage condition, then the first switch is in the closed state, and the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset second voltage condition, then the fifth switch is in the closed state, and the first switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fourth voltage condition, then the fifth auxiliary switch is in the closed state, and the first switch, the fifth switch, and the first auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fifth voltage condition, then the first auxiliary switch is in the closed state, and the first switch, the fifth switch, and the fifth auxiliary switch are all in the open state. Alternatively, when the common terminal of the selection unit is connected to the third selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the second switch and the sixth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the second switch is in the open state and the sixth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the second switch is in the closed state and the sixth switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fourth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the third switch and the seventh switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the third switch is in the open state and the seventh switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the third switch is in the closed state and the seventh switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fifth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the fourth switch and the eighth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the fourth switch is in the open state and the eighth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the fourth switch is in the closed state and the eighth switch is in the open state.

[0014] In this embodiment of the invention, the switch state detection circuit of the demand response enable device includes a control unit and a selection unit. The selection unit includes a common terminal and multiple selection terminals. Each demand response mode port of the demand response enable device is connected to a selection terminal, and the common terminal is connected to the control unit. The control unit controls the selection unit to connect the common terminal to one of the selection terminals and obtains the voltage of the common terminal. Based on the voltage of the common terminal, the switch state of the switch corresponding to the demand response mode port connected to the selection terminal is determined. Compared with the existing detection methods for various switch states of DRED, this embodiment of the invention, when detecting the switch state of the DRED, controls the common terminal of the selection unit to connect only to one of the selection terminals, and detects the switch state of the switch corresponding to the demand response mode port connected to the connected selection terminal separately. In this way, other switch branches can be isolated, avoiding mutual influence between the switch states of various switch branches, thereby improving the accuracy of the detection results, realizing coordinated scheduling between the inverter and the grid, and ensuring the stability and security of grid operation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] In the attached diagram: Figure 1 A circuit structure diagram of a DRED provided in an embodiment of the present invention; Figure 2 A structural diagram of a switch state detection circuit for a demand response enabling device provided in an embodiment of the present invention; Figure 3 Example of a switch state detection circuit for a demand response enable device provided in an embodiment of the present invention. Figure 1 ; Figure 4 Example of a switch state detection circuit for a demand response enable device provided in an embodiment of the present invention. Figure 2 ; Figure 5 A flowchart of a method for detecting the switch state of a demand response enabling device provided in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0018] In the description of this specification, the terms "comprising," "including," "having," and "containing" are open-ended terms, meaning that they include but are not limited to. The terms "an embodiment," "a specific embodiment," "some embodiments," and "for example," etc., refer to specific features, structures, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. The order of steps involved in the various embodiments is used to illustrate the implementation of this application, and the order of steps is not limited and can be adjusted appropriately as needed.

[0019] In the description of this specification, the terms "first" and "second," etc., are used to distinguish different objects or to distinguish different treatments of the same object, rather than to describe a specific order of objects.

[0020] In the description of this specification, "and / or" is merely a way of describing the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0021] The Demand Response Enable (DRED) device is an external control device used for grid dispatching. Its core function is to receive grid commands and control the inverter to execute the Demand Response Mode (DRM). The circuit structure of the DRED will be described below.

[0022] Figure 1 A circuit structure diagram of a DRED provided in an embodiment of the present invention is shown below. Figure 1 As shown, DRED includes 12 switches, namely the first switch S1, the second switch S2, the third switch S3, the fourth switch S4, the fifth switch S5, the sixth switch S6, the seventh switch S7, the eighth switch S8, the ninth switch S9, the tenth switch S0, the first auxiliary switch S1a, and the fifth auxiliary switch S5a.

[0023] DRED also includes five demand response mode ports and a reference ground port REF GEN / 0. The five demand response mode ports are: first demand response mode port COM LOAD / 0, second demand response mode port DRM1 / 5, third demand response mode port DRM2 / 6, fourth demand response mode port DRM3 / 7, and fifth demand response mode port DRM4 / 8.

[0024] DRED also includes a demand response mode detection resistor R0 for identifying demand response modes.

[0025] It should be noted that the functions and positions of the aforementioned switches, demand response mode ports, reference ground ports, and demand response mode detection resistor R0 in the circuit can be referenced from existing technologies and relevant regulations, and will not be elaborated further here.

[0026] based on Figure 1 The existing method for detecting the switch status of the DRED circuit shown involves applying voltage to each switch branch of the DRED and determining the switch status of each branch by detecting the voltage division state. However, since the DRED has multiple switch branches, and the switches of DRM1 / 4, DRM2 / 5, DRM3 / 7, and DRM4 / 8 converge to the same common coupling point after being closed, and are connected to REF GEN / 0 or COM LOAD / 0 through resistor R0, when some switches are closed and voltage is applied simultaneously, the current flowing through resistor R0 changes, thereby changing the voltage division value at the common coupling point. Ultimately, this causes the detection of each switch to interfere with each other, resulting in inaccurate detection results. Consequently, it is impossible to achieve coordinated scheduling between the inverter and the grid, and the stability and security of grid operation cannot be guaranteed.

[0027] Therefore, embodiments of the present invention provide a switch state detection circuit for a demand response enable device, which can avoid mutual interference between the switch states of each switch branch when detecting the switch state of DRED, thereby improving the accuracy of the detection results.

[0028] Figure 2 A structural diagram of the switch state detection circuit of the demand response enable device provided in the embodiments of the present invention is shown below. Figure 2 As shown, the switch state detection circuit includes a control unit 1 and a selection unit 2; the selection unit 2 includes a common terminal D and multiple selection terminals A0-AX; in, Figure 1 Each demand response mode port in the system is connected to a selection port, and the common port is connected to control unit 1.

[0029] Control unit 1 can control selection unit 2 to connect the common terminal to one of the selection terminals, obtain the voltage of the common terminal, and determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal based on the voltage of the common terminal.

[0030] In one embodiment, since each demand-response mode port is connected to a selection port, Figure 1 The system includes 5 demand response mode ports, therefore, the number of selection terminals for selection unit 2 is at least 5.

[0031] The five selection terminals can be the first selection terminal A0, the second selection terminal A1, the third selection terminal A2, the fourth selection terminal A3, and the fifth selection terminal A4, respectively. The first selection terminal A0 is connected to the first demand response mode port COM LOAD / 0, and the first demand response mode port COM LOAD / 0 is connected to the ninth switch S9 and the tenth switch S0; The second selection terminal A1 is connected to the second demand response mode port DRM1 / 5, and the second demand response mode port DRM1 / 5 is connected to the first switch S1, the fifth switch S5, the first auxiliary switch S1a and the fifth auxiliary switch S5a. The third selection terminal A2 is connected to the third demand response mode port DRM2 / 6, and the third demand response mode port DRM2 / 6 is connected to the second switch S2 and the sixth switch S6. The fourth selection terminal A3 is connected to the fourth demand response mode port DRM3 / 7, and the fourth demand response mode port DRM3 / 7 is connected to the third switch S3 and the seventh switch S7; The fifth selection terminal A4 is connected to the fifth demand response mode port DRM4 / 8, and the fifth demand response mode port DRM4 / 8 is connected to the fourth switch S4 and the eighth switch S8.

[0032] Based on the above embodiments, the control unit 1 can be specifically used for: The control selection unit 2 connects the common terminal D to the first selection terminal A0 and obtains the common terminal voltage Vd. Based on the common terminal voltage Vd, it determines the switching state of the ninth switch S9 and the tenth switch S0. Alternatively, the control selection unit 2 connects the common terminal A to the second selection terminal A1 and obtains the common terminal voltage Vd. Based on the common terminal voltage Vd, the switching states of the first switch S1, the fifth switch S5, the first auxiliary switch S1a, and the fifth auxiliary switch S5a are determined. Alternatively, the control selection unit 2 connects the common terminal D to the third selection terminal A2 and obtains the common terminal voltage Vd. Based on the common terminal voltage Vd, the switching states of the second switch S2 and the sixth switch S6 are determined. Alternatively, the control selection unit 2 connects the common terminal D to the fourth selection terminal A3 and obtains the common terminal voltage Vd. Based on the common terminal voltage Vd, the switching states of the third switch S3 and the seventh switch S7 are determined. Alternatively, the control selection unit 2 connects the common terminal D to the fifth selection terminal A4 and obtains the common terminal voltage Vd. Based on the common terminal voltage Vd, it determines the switching states of the fourth switch S4 and the eighth switch S8.

[0033] so, Figure 2The switch status detection circuit shown controls the common terminal of the selection unit to be connected to one of the selection terminals each time when detecting the switch status of the DRED. It detects the switch status of the switch corresponding to the demand response mode port connected to the connected selection terminal separately. In this way, other switch branches can be isolated to avoid mutual influence between the switch statuses of each switch branch, thereby improving the accuracy of the detection results, realizing the coordinated scheduling between the inverter and the grid, and ensuring the stability and safety of grid operation.

[0034] The specific implementation process of the control unit determining the switching state of the switch corresponding to the demand response mode port connected to the selection terminal based on the common terminal voltage will be described in the embodiments of the switching state detection method of the demand response enable device below, and will not be elaborated here.

[0035] In one embodiment, selection unit 2 may include a multiplexer, which includes a common terminal and multiple selection terminals, that is, selection unit includes a common terminal D and multiple selection terminals A0-AX.

[0036] Alternatively, the selection unit 2 may include multiple selection switches, with the first ends of the multiple selection switches connected to each other as a common terminal D, and the second end of each selection switch serving as a selection terminal of the selection unit, thus obtaining multiple selection terminals A0-AX.

[0037] In specific implementation, selection unit 2 can be implemented by a multiplexer. The multiplexer includes multiple analog switches. One end of each analog switch is connected to each other as a common terminal, and the other end of each analog switch is used as a selection terminal. By utilizing the isolation characteristics of the multiplexed analog switches, other switch branches can be isolated when detecting the switching status of a single switch branch, thus avoiding mutual interference between the switch branches.

[0038] Alternatively, selection unit 2 can be implemented using multiple selection switches. For example, selection unit 2 can include 5 selection switches. The first ends of the 5 selection switches are connected to each other as a common end, and the second end of each selection switch serves as a selection end of the selection unit, which are the 5 selection ends of selection unit 2. The selection switches can be analog switches, electronic switches, transistor switches, relays, etc.

[0039] In a specific implementation, the selection unit 2 may also include a control terminal, which is connected to the control unit, receives control signals sent by the control unit, and connects the common terminal to one of the selection terminals according to the control signals.

[0040] In one embodiment, Figure 2 The switch state detection circuit shown may also include voltage divider resistors and a power supply; the selection unit may also include a ground terminal; The two ends of the voltage divider resistor are connected to the power supply and the common terminal of the selection unit, respectively. The ground terminal of the selection unit is connected to the reference ground port of the demand response enable device. Alternatively, the two ends of the voltage divider resistor are connected to the common terminal and the ground terminal of the selection unit, respectively, and the power supply is connected to the reference ground port of the demand response enable device.

[0041] In specific implementation, such as Figure 3 The image shown is an example of a switch state detection circuit for a demand response enabling device provided in an embodiment of the present invention. Figure 1 , Figure 3 In the middle, the two ends of the voltage divider resistor R1 are connected to the power supply VCC and the common terminal D of the selection unit 2, respectively. The ground terminal GND of the selection unit 2 is connected to the reference ground port REF GEN / 0 of DRED.

[0042] Or, such as Figure 4 The image shown is an example of a switch state detection circuit for a demand response enabling device provided in an embodiment of the present invention. Figure 2 , Figure 4 In the middle, the two ends of the voltage divider resistor R1 are connected to the common terminal D and the ground terminal GND of the selection unit 2, respectively, and the power supply VCC is connected to the reference ground port REF GEN / 0 of DRED.

[0043] It should be noted that, Figure 3 and Figure 4 In the middle, selection unit 2 includes an 8-channel multiplexer U1. The 8-channel multiplexer U1 includes a common terminal D, eight selection terminals A0-A7, and three control terminals M0-M2. Since... Figure 1 The DRED shown includes 5 demand response mode ports. Therefore, in the 8-channel multiplexer U1, only the 5 selection terminals A0-A4 are connected to one demand response mode port respectively, while the other 3 selection terminals A5-A7 are idle. The control unit 1 sends control signals to the control terminals M0-M2 of the selection unit 2 to control the common terminal D of the 8-channel multiplexer U1 to be connected to one of the selection terminals A0-A4.

[0044] In summary, the switch state detection circuit of the demand response enable device provided in this embodiment of the invention can control one of the selection terminals and the common terminal to be turned on by the selection unit, while other switch channels are isolated. In this way, the voltage of the power supply is only applied to the demand response mode port connected to the selection terminal of the turned-on switch channel. Therefore, even if the switch state of the switch branch of other channels changes, it will not affect the detection of the switch state of the switch branch of the turned-on switch channel. Therefore, when detecting the switch state of a single switch branch, the voltage division value of each switch branch is a fixed value, thereby realizing a one-to-one correspondence between the switch state of each switch branch of DRED and the voltage of the common terminal, ensuring the accuracy of the detection results.

[0045] Based on the switch state detection circuit of the demand response enabling device described above, this embodiment of the invention also provides a switch state detection method for the demand response enabling device, which is applied to the aforementioned switch state detection circuit. Figure 5 As shown, the switch state detection method includes: Step 501: With the common terminal of the selection unit connected to any one of the selection terminals, obtain the voltage of the common terminal; Step 502: Determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal based on the common terminal voltage.

[0046] In step 501 above, when the common terminal of the selection unit is turned on with any one of the selection terminals, the common terminal voltage Vd is obtained. The common terminal voltage Vd can be the voltage obtained after being processed by the operational amplifier.

[0047] In step 502 above, the switching state of the switch corresponding to the demand response mode port connected to the selection terminal is determined by the common terminal voltage.

[0048] It should be noted that the current demand response mode of DRED is determined by the switching status of each switch branch. Based on existing regulations, DRED's demand response modes include nine modes, namely DRM0 to DRM8. Among them, DRM0 mode is the highest priority demand response mode, which involves disconnecting the inverter. The priorities of DRM1 to DRM8 are not specified. Therefore, based on the switching status of each switch branch, if the DRM0 mode is met, the inverter will directly perform a disconnect shutdown and will not respond to DRM1 to DRM8 modes.

[0049] In one embodiment, step 502 above may specifically include: When the common terminal of the selection unit is connected to the first selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the ninth switch is in the open state. If the common terminal voltage meets the preset second voltage condition, then the ninth switch is closed and the tenth switch is closed. If the common terminal voltage does not meet the preset first voltage condition and the preset second voltage condition, then the ninth switch is closed and the tenth switch is open. Based on the common terminal voltage, the resistance value of the demand response mode detection resistor is determined, and based on the preset resistance threshold range of the resistance value, the control state of the demand response enabling device is determined.

[0050] In specific implementation, refer to Figure 3 or Figure 4 When the common terminal D of the selection unit 2 is connected to the first selection terminal A0, the switching states of the ninth switch S9 and the tenth switch S0 are detected (i.e., DRM0 is detected).

[0051] Specifically, if the common terminal voltage Vd meets the preset first voltage condition, then S9 is in the off state. Since S9 is the total enable switch for DRED, the switching state of S0 does not need to be considered when S9 is off. The preset first voltage condition can be Vd = V CC Or Vd and V CC The difference meets the preset difference range, V CC This refers to the power supply voltage.

[0052] If the common terminal voltage Vd satisfies the preset second voltage condition, then S9 is closed and S0 is closed. The preset second voltage condition can be Vd=0 or Vd is near 0.

[0053] If the common terminal voltage Vd does not meet the preset first voltage condition and the preset second voltage condition, then the ninth switch is considered to be in the closed state and the tenth switch is in the open state. In this case, it can be determined by the formula Vd=V CC Calculate the resistance value of the demand response mode detection resistor R0 using (R0+R1)×R0, given the common terminal voltage Vd (obtained by detection) and the power supply voltage V. CC The resistance value of R0 can be calculated from the values ​​of the fixed-value resistor R1 and the voltage divider resistor R1 (fixed value) of the switch state detection circuit. Based on the resistance value of R0, the control state of the demand response enabler can be determined. For example, if the resistance value of R0 falls within or near the preset resistance threshold range of 20KΩ, the control state of the demand response enabler is considered to be in a state where normal grid-connected power generation is permitted. If the resistance value of R0 falls within or near the preset resistance threshold range of 15KΩ, the control state of the demand response enabler is considered to be in a state where power limiting regulation is triggered. Additionally, if the resistance value of R0 is greater than 20KΩ, this resistance value can also be detected.

[0054] It should be noted that if both S9 and S0 are closed, the response conditions for DRM0 mode are met, and the inverter directly performs a disconnection shutdown and no longer responds to DRM1 to 8 modes. Therefore, the determination of whether the response conditions for DRM1 to 8 are met is based on S9 being closed and S0 being open.

[0055] In one embodiment, step 502 may further include performing the following operation when S9 is in the closed state and S0 is in the open state: When the common terminal of the selection unit is connected to the second selection terminal, if the voltage of the common terminal meets the preset first voltage condition, then the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset third voltage condition, then the first switch is in the closed state, and the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset second voltage condition, then the fifth switch is in the closed state, and the first switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fourth voltage condition, then the fifth auxiliary switch is in the closed state, and the first switch, the fifth switch, and the first auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fifth voltage condition, then the first auxiliary switch is in the closed state, and the first switch, the fifth switch, and the fifth auxiliary switch are all in the open state. Alternatively, when the common terminal of the selection unit is connected to the third selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the second switch and the sixth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the second switch is in the open state and the sixth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the second switch is in the closed state and the sixth switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fourth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the third switch and the seventh switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the third switch is in the open state and the seventh switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the third switch is in the closed state and the seventh switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fifth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the fourth switch and the eighth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the fourth switch is in the open state and the eighth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the fourth switch is in the closed state and the eighth switch is in the open state.

[0056] In specific implementation, refer to Figure 3 or Figure 4 If the ninth switch S9 is detected to be closed and the tenth switch S0 is detected to be open, then the switch status detection of other switch branches is performed.

[0057] When the common terminal D of the selection unit 2 is connected to the second selection terminal A1, the switching states of the first switch S1, the fifth switch S5, the first auxiliary switch S1a and the fifth auxiliary switch S5a are detected, that is, the DRM1 / 5 mode is detected.

[0058] Specifically, if the common terminal voltage Vd meets the above-mentioned preset first voltage condition, then S1, S5, S1a and S5a are all in the off state.

[0059] If the common terminal voltage Vd meets the preset third voltage condition, then S1 is in a closed state, and S5, S1a, and S5a are all in an open state. The preset third voltage condition can be Vd = VCC / (R0+R1)×R0 or the difference between Vd and VCC / (R0+R1)×R0 meets a preset difference range. In other words, if the common terminal voltage Vd meets the above-mentioned preset third voltage condition, then S1 is in a closed state, and S5, S1a, and S5a are all in an open state.

[0060] If the common terminal voltage Vd satisfies the above-mentioned preset second voltage condition, then S5 is in a closed state, and S1, S1a and S5a are all in an open state.

[0061] If the common terminal voltage Vd meets the preset fourth voltage condition, then S5a is closed, and S1, S5, and S1a are all open. The preset fourth voltage condition can be Vd = VF or the difference between Vd and VF meets a preset difference range. VF represents the voltage drop between the demand response mode port DRM1 / 5 and COM LOAD / 0. Based on existing regulations, the value range of VF can be 1.5V-1.6V. Therefore, if the common terminal voltage Vd is in the range of 1.5V-1.6V, then S5a is closed, and S1, S5, and S1a are all open.

[0062] If the common terminal voltage Vd satisfies the preset fifth voltage condition, then S1a is in the closed state, and S1, S5, and S5a are all in the open state; whereby the preset fifth voltage condition can be Vd = (V CC -VF) / (R0+R1)×R0+VF or Vd and (V CC The error of -VF) / (R0+R1)×R0+VF meets the preset error range, and the value of VF can be in the range of 1.5V-1.6V. Therefore, if the common terminal voltage meets the preset fifth voltage condition, then S1a is in the closed state, and S1, S5 and S5a are all in the open state.

[0063] It should be noted that, to avoid the common terminal voltage Vd when S1 is closed being the same as the common terminal voltage Vd when S5a is closed, the power supply voltage V... CC It cannot be equal to VF×R0 / (R0+R1); to avoid the voltage Vd being the same when S1 is closed as when S1a is closed, the voltage V of the power supply is... CC It cannot be equal to VF×(1+R0 / (R0+R1)).

[0064] When the common terminal D of selection unit 2 is connected to the third selection terminal A2, the switching states of the second switch S2 and the sixth switch S6 are detected, that is, the DRM2 / 6 mode is detected.

[0065] Specifically, if the common terminal voltage Vd meets the above-mentioned preset first voltage condition, then both S2 and S6 are in the off state.

[0066] If the common terminal voltage Vd satisfies the above-mentioned preset second voltage condition, then S2 is in the open state and S6 is in the closed state.

[0067] If the common terminal voltage Vd satisfies the aforementioned preset third voltage condition, then S2 is in a closed state and S6 is in an open state.

[0068] When the common terminal D of selection unit 2 is connected to the fourth selection terminal A3, the switching states of the third switch S3 and the seventh switch S7 are detected, that is, the DRM3 / 7 mode is detected.

[0069] Specifically, if the common terminal voltage Vd meets the preset first voltage condition, then both S3 and S7 are in the off state.

[0070] If the common terminal voltage Vd satisfies the above-mentioned preset second voltage condition, then S3 is in the open state and S7 is in the closed state.

[0071] If the common terminal voltage Vd satisfies the aforementioned preset third voltage condition, then S3 is in a closed state and S7 is in an open state.

[0072] When the common terminal D of selection unit 2 is connected to the fifth selection terminal A4, the switching states of the fourth switch S4 and the eighth switch S8 are detected, that is, the DRM4 / 8 mode is detected.

[0073] Specifically, if the common terminal voltage Vd meets the above-mentioned preset first voltage condition, then S4 and S8 are both in the off state.

[0074] If the common terminal voltage Vd satisfies the above-mentioned preset second voltage condition, then S4 is in the open state and S8 is in the closed state.

[0075] If the common terminal voltage Vd satisfies the aforementioned preset third voltage condition, then S4 is in a closed state and S8 is in an open state.

[0076] Based on the above description, when the common terminal of the selection unit is connected to any one of the selection terminals, the switching state of the switch corresponding to the demand response mode port connected to the selection terminal is determined according to the voltage of the common terminal. Table 1 can be referenced; it is a table comparing the selection terminal's on / off state, the common terminal voltage, and the switching state. In Table 1, M0-M2 are the control signals received by the three control terminals of the selection unit. For example, if M0-M2 are 0, 0, and 0 respectively, then the common terminal D is connected to the first selection terminal A0, detecting the DRM0 mode. S0-S9, S1a, and S5a are 1 when closed and 0 when open.

[0077] Table 1. Comparison of Selected Terminal On-State, Common Terminal Voltage, and Switching State In summary, the switch state detection circuit and method for the demand response enable device provided in this embodiment of the invention can detect the switch states of S9 and S0 by separately turning on the common terminal D and the first selection terminal A0 (i.e., turning on COM LOAD / 0), and can determine the resistance value of the external resistor R0, distinguish between 15KΩ and 20KΩ resistors, and thus determine the control state of the demand response enable device; it can detect the switch states of S1, S5, S1a and S5a by separately turning on the common terminal D and the second selection terminal A1 (i.e., turning on DRM1 / 5); it can detect the switch states of S2 and S6 by separately turning on the common terminal D and the third selection terminal A2 (i.e., turning on DRM2 / 6); it can detect the switch states of S3 and S7 by separately turning on the common terminal D and the fourth selection terminal A3 (i.e., turning on DRM3 / 7); and it can detect the switch states of S4 and S8 by separately turning on the common terminal D and the fifth selection terminal A4 (i.e., turning on DRM4 / 8). This solution features a simple circuit structure, with no mutual interference between detection channels and strong anti-interference capabilities. It can improve the accuracy of detection results, reduce circuit hardware costs, and its voltage judgment logic is clear and simple, thereby improving detection efficiency.

[0078] This invention also provides an inverter that includes the switching state detection circuit of the demand response enable device described above. Since the implementation principle of this inverter is the same as the switching state detection circuit and method of the demand response enable device described above, it will not be described in detail here.

[0079] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0081] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0082] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0083] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A switch state detection circuit for a demand response enabling device, the demand response enabling device comprising multiple demand response mode ports, characterized in that, The switch state detection circuit includes: a control unit and a selection unit; the selection unit includes a common terminal and multiple selection terminals; Each demand response mode port is connected to a selection port, and the common port is connected to the control unit. The control unit is used to control the selection unit to connect the common terminal to one of the selection terminals, obtain the voltage of the common terminal, and determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal based on the voltage of the common terminal.

2. The switch state detection circuit as described in claim 1, characterized in that, The selection unit includes a multiplexer, which includes a common terminal and a plurality of selection terminals.

3. The switch state detection circuit as described in claim 1, characterized in that, The selection unit includes multiple selection switches. The first ends of the multiple selection switches are connected to each other as a common terminal, and the second end of each selection switch serves as a selection terminal of the selection unit.

4. The switch state detection circuit as described in claim 1, characterized in that, The multiple selection terminals include a first selection terminal, a second selection terminal, a third selection terminal, a fourth selection terminal, and a fifth selection terminal; The first selection terminal is connected to the first demand response mode port, and the first demand response mode port is connected to the ninth switch and the tenth switch. The second selection terminal is connected to the second demand response mode port, and the second demand response mode port is connected to the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch; The third selection terminal is connected to the third demand response mode port, and the third demand response mode port is connected to the second switch and the sixth switch; The fourth selection terminal is connected to the fourth demand response mode port, and the fourth demand response mode port is connected to the third switch and the seventh switch; The fifth selection terminal is connected to the fifth demand response mode port, and the fifth demand response mode port is connected to the fourth switch and the eighth switch.

5. The switch state detection circuit as described in claim 4, characterized in that, The control unit is used for: The control selection unit connects the common terminal to the first selection terminal and obtains the voltage of the common terminal. Based on the voltage of the common terminal, it determines the switching state of the ninth switch and the tenth switch. Alternatively, the control selection unit connects the common terminal to the second selection terminal and obtains the voltage of the common terminal. Based on the voltage of the common terminal, it determines the switching states of the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch. Alternatively, the control selection unit can connect the common terminal to the third selection terminal and obtain the voltage of the common terminal, and determine the switching state of the second and sixth switches based on the voltage of the common terminal. Alternatively, the control selection unit can connect the common terminal to the fourth selection terminal and obtain the voltage of the common terminal, and determine the switching state of the third switch and the seventh switch based on the voltage of the common terminal. Alternatively, the control selection unit can connect the common terminal to the fifth selection terminal and obtain the voltage of the common terminal, and determine the switching state of the fourth and eighth switches based on the voltage of the common terminal.

6. The switch state detection circuit as described in claim 1, characterized in that, The switch status detection circuit also includes voltage divider resistors and a power supply; the selection unit also includes a ground terminal; The two ends of the voltage divider resistor are respectively connected to the power supply and the common terminal of the selection unit, and the ground terminal of the selection unit is connected to the reference ground port of the demand response enable device. Alternatively, the two ends of the voltage divider resistor are connected to the common terminal and the ground terminal of the selection unit, respectively, and the power supply is connected to the reference ground port of the demand response enable device.

7. A method for detecting the switching state of a demand response enabling device, characterized in that, The switch state detection circuit applied to the demand response enable device as described in any one of claims 1-6 includes: When the common terminal of the selection unit is connected to any one of the selection terminals, obtain the common terminal voltage; Based on the common terminal voltage, determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal.

8. The method as described in claim 7, characterized in that, Based on the common terminal voltage, determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal, including: When the common terminal of the selection unit is connected to the first selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the ninth switch is in the open state. If the common terminal voltage meets the preset second voltage condition, then the ninth switch is closed and the tenth switch is closed. If the common terminal voltage does not meet the preset first voltage condition and the preset second voltage condition, then the ninth switch is closed and the tenth switch is open. Based on the common terminal voltage, the resistance value of the demand response mode detection resistor is determined, and based on the preset resistance threshold range of the resistance value, the control state of the demand response enabling device is determined.

9. The method as described in claim 8, characterized in that, Based on the common terminal voltage, determine the switching state of the switch corresponding to the demand response mode port connected to the selection terminal, including the condition that the ninth switch is closed and the tenth switch is open: When the common terminal of the selection unit is connected to the second selection terminal, if the voltage of the common terminal meets the preset first voltage condition, then the first switch, the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset third voltage condition, then the first switch is in the closed state, and the fifth switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset second voltage condition, then the fifth switch is in the closed state, and the first switch, the first auxiliary switch, and the fifth auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fourth voltage condition, then the fifth auxiliary switch is in the closed state, and the first switch, the fifth switch, and the first auxiliary switch are all in the open state; if the voltage of the common terminal meets the preset fifth voltage condition, then the first auxiliary switch is in the closed state, and the first switch, the fifth switch, and the fifth auxiliary switch are all in the open state. Alternatively, when the common terminal of the selection unit is connected to the third selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the second switch and the sixth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the second switch is in the open state and the sixth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the second switch is in the closed state and the sixth switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fourth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the third switch and the seventh switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the third switch is in the open state and the seventh switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the third switch is in the closed state and the seventh switch is in the open state. Alternatively, when the common terminal of the selection unit is connected to the fifth selection terminal, if the voltage of the common terminal meets the preset first voltage condition, the fourth switch and the eighth switch are in the open state; if the voltage of the common terminal meets the preset second voltage condition, the fourth switch is in the open state and the eighth switch is in the closed state; if the voltage of the common terminal meets the preset third voltage condition, the fourth switch is in the closed state and the eighth switch is in the open state.

10. An inverter, characterized in that, Includes a switch state detection circuit for a demand response enabling device as described in any one of claims 1-6.

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