Interconnected inverters and methods of manufacturing interconnected inverters

Abstract

A system of interconnecting inverters includes an inverter (120) that converts DC power from a DC power source into AC power and supplies the AC power to an AC power line, an RDC (140) that converts a voltage value obtained by a voltage sensor (71U, 71V) that obtains a voltage value of an output voltage from the inverter to a power grid (90) into electric angle information that shows a phase angle of the output voltage, and an ECU (110) that controls the inverter to supply alternating current that is synchronized with alternating current flowing through the AC power line by using a time at which an angle shown in the electric angle information given from the RDC reaches a prescribed angle. Additional cost for conversion can be reduced.

Description

Technical Field

[0001] This disclosure relates to interconnect inverters and methods of manufacturing interconnect inverters, and more specifically to interconnect inverters suitable for interconnecting direct-current (DC) power to power lines for alternating-current (AC) power, and methods of manufacturing such interconnect inverters. Background Technology

[0002] It is conventionally known to convert DC power into AC power synchronized with the AC voltage of an AC power grid (see Japanese Patent Application Publication No. 9-271176). Such a grid-connected inverter includes an A / D port for receiving voltage sensor values ​​for synchronization with the three-phase AC voltage at the grid connection point. Summary of the Invention

[0003] However, inverters installed in vehicles typically do not include an A / D port for receiving voltage sensor values. Therefore, when attempting to divert an onboard inverter to a grid-connected inverter, a new A / D port must be installed. Consequently, this diversion incurs additional costs.

[0004] This disclosure is made to address the aforementioned problems, and its purpose is to provide an interconnect inverter that enables a reduction in the additional costs required for switching, as well as a method for manufacturing the interconnect inverter.

[0005] The disclosed interconnected inverter includes: an inverter circuit that converts DC power from a DC power source into AC power and supplies the AC power to an AC power line; a resolver digital converter that converts a voltage value obtained by a voltage sensor into electrical angle information indicating the phase angle of the output voltage from the inverter circuit to the AC power line, wherein the voltage sensor obtains the voltage value of the output voltage; and a control unit that controls the inverter circuit to supply AC power synchronized with the AC power flowing through the AC power line at the moment when the angle indicated by the electrical angle information given by the resolver digital converter reaches a predetermined angle.

[0006] With this configuration, when the voltage value of the AC power in the AC power line obtained through the voltage sensor is provided to the resolver-to-digital converter (RDBDC), the electrical angle of the AC power and the electrical angle provided from the RDBDC are synchronized with each other at a specific angle. When the frequency of the AC power in the AC power line is known (e.g., 50Hz or 60Hz), and when synchronization is achieved at the specific angle, the output from the inverter circuit can be synchronized with the AC power in the AC power line. Therefore, there is no need to set up a new A / D port for receiving voltage values ​​from the voltage sensor. This reduces the additional costs required for conversion.

[0007] The inverter circuit, resolver-to-digital converter, and control unit can be reused from a system used to drive a motor. This system can be a vehicle. Therefore, cost reduction is possible through this reuse.

[0008] The AC power line can be a three-phase AC power line. The control unit can control the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power line at the moment when the angle shown in the electrical angle information given from the resolver digital converter reaches 0 degrees or ±180 degrees. When the AC power is three-phase AC power, the resolver digital converter provides a synchronization signal at the moment when the electrical angle (voltage phase) of the AC power reaches 0 degrees or ±180 degrees. Therefore, precise synchronization can be achieved by using such timing. The AC power line can also be a single-phase AC power line.

[0009] According to another aspect of this disclosure, a method for manufacturing an interconnected inverter is a method for converting a resolver-to-digital converter, an inverter circuit, and a control unit mounted on a system, the system comprising: an inverter circuit that converts DC power from a DC power source into AC power; and a motor that uses the AC power from the inverter circuit to generate driving force.

[0010] The system comprises a rotary transformer that detects values ​​related to the rotation of the motor, a rotary transformer digital converter that converts the values ​​from the rotary transformer into electrical angle information showing the phase angle related to the rotation, and a control unit that controls the inverter circuit by using the angle information shown from the electrical angle information given by the rotary transformer digital converter.

[0011] A method for manufacturing an interconnected inverter includes: providing terminals for connecting DC power to the input of the inverter; providing terminals for connecting the output of the inverter circuit connected to the motor to an AC power line; providing terminals for connecting a signal line from a voltage sensor to a resolver digital converter, the voltage sensor obtaining the voltage value of the output voltage to the AC power line; and modifying the control method of the control unit to control the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power line at the moment when a predetermined angle is reached using electrical angle information provided by the resolver digital converter. With this configuration, the additional costs required for conversion can be reduced.

[0012] The foregoing and other objects, features, aspects and advantages of this disclosure will become more apparent from the following detailed description of this disclosure when taken in conjunction with the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating a general configuration of the system surrounding the inverter mounted on the vehicle in this embodiment.

[0014] Figure 2 The graph shows the sin and cos signals provided by the rotary transformer in this embodiment and the resulting rotation angle.

[0015] Figure 3 This is a diagram illustrating a general configuration of the system surrounding the inverter after the application has been switched from an in-vehicle application to a grid-connected application in the first embodiment.

[0016] Figure 4 The diagram shows the signal provided when the voltages of two phases of the three-phase AC power are supplied to the RDC in the first embodiment.

[0017] Figure 5 This is a diagram illustrating a summary of the configuration of the system around the inverter after the application has been switched from an in-vehicle application to a grid-connected application in the second embodiment.

[0018] Figure 6 The graph shown in the second embodiment is a signal provided when the voltages of two single-phase alternating currents that are out of phase are supplied to the RDC. Detailed Implementation

[0019] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. In the following description, the same elements are labeled with the same reference numerals, and their designations and functions are identical. Therefore, their detailed description will not be repeated.

[0020] [First Embodiment]

[0021] Figure 1This is a diagram illustrating a schematic of the structure of the system surrounding the inverter mounted on the vehicle in this embodiment. (Refer to...) Figure 1 Vehicle 1 includes a Power Control Unit (PCU) 10, an energy storage device 20, a motor generator 30, a resolver 31, and current sensors 32U, 32V, and 32W. PCU 10 includes an Electronic Control Unit (ECU) 110, an inverter 120, a boost converter 130, a resolver-to-digital converter (hereinafter referred to as "RDC") 140, a capacitor 150, and a voltage sensor 151. ECU 110 includes a Central Processing Unit (CPU) (not shown) and a memory (not shown), as well as an analog-to-digital converter circuit 111 and a duty cycle command value calculator 112.

[0022] The energy storage device 20 includes a battery assembly containing multiple individual cells. Each individual cell is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The energy storage device 20 supplies electricity to the motor generator 30 to generate the driving force for the vehicle 1, and the electricity generated by the motor generator 30 is stored in the energy storage device 20.

[0023] The boost converter 130 boosts the voltage applied to the inverter 120 by the energy storage device 20 and steps down the voltage from the inverter 120 to charge the energy storage device 20. The capacitor 150 smooths the voltage boosted by the boost converter 130. The voltage sensor 151 detects the voltage VH between opposite terminals of the capacitor 150 and provides an analog signal representing the detected voltage VH.

[0024] The inverter 120 converts the DC power from the boost converter 130 into AC power according to the control signal from the ECU 110 and supplies the AC power to the motor generator 30. It also converts the AC power regenerated by the motor generator 30 into DC power and supplies the DC power to the energy storage device 20 through the boost converter 130.

[0025] The motor generator 30 drives the wheels of the vehicle 1 by rotating based on the AC power supplied from the inverter 120, and supplies the AC power regenerated by the deceleration force from the wheels to the inverter 120.

[0026] The rotary transformer 31 is an angle sensor that provides the rotation angle of the rotor as a two-phase AC voltage (analog signal), and includes an excitation coil, a rotor including a repeating coil, and two-phase output coils configured to form an angle of 90 degrees with respect to each other with the rotor's rotation axis defined as the center. Thus, the rotor of the rotary transformer 31 is connected to the rotation axis of the motor generator 30, and therefore the rotary transformer 31 acts as an angle sensor for the motor generator 30.

[0027] When an excitation signal is applied to the primary excitation coil in the rotary transformer 31, the rotor, which is connected to the shaft of the motor generator 30, rotates. The excitation signal generates an induced electromotive force (EMF) in the repeating coil of the rotating rotor. The induced EMF in the repeating coil generates an induced EMF in the output coil, so that the two-phase output coils on the secondary side provide sin and cos signals corresponding to the rotor angle.

[0028] Figure 2 A graph showing the sin and cos signals provided by the rotary transformer 31 in this embodiment, and the resulting rotation angle, is provided. (Refer to...) Figure 2 The first row of the graph shows the change in the sin signal, the second row shows the change in the cos signal, and the third row shows the rotation angle. Figure 2 The first row of the graph shows a sine curve plotted as a line representing the amplitude of the waveform. Figure 2 In the second row of the graph, the cosine curve is drawn by showing the amplitude of the waveform.

[0029] Return to reference Figure 1 RDC 140 is an integrated circuit (IC) that calculates the rotation angle of the rotor of the resolver 31 (hereinafter referred to as "resolver angle") using signals provided from the resolver 31 and provides a digital signal representing the rotation angle. Since the rotor of the resolver 31 is connected to the rotation shaft of the motor generator 30 in this embodiment, RDC 140 calculates the rotation angle of the motor generator 30.

[0030] Refer again Figure 2 The graph in the third row shows the change in the resolver angle calculated by RDC 140. The points where the sine value is 0 shown in the graph in the first row are calculated as the points of 0 degrees, 180 degrees, and 360 degrees of the resolver angle, and the points where the cosine value is 0 shown in the graph in the second row are calculated as the points of 90 degrees and 270 degrees of the resolver angle.

[0031] Return to reference Figure 1Current sensors 32U, 32V, and 32W detect the U-phase, V-phase, and W-phase currents Iu, Iv, and Iw of the three-phase alternating current flowing between the inverter 120 and the motor generator 30, and provide analog signals representing the detected currents Iu, Iv, and Iw, respectively.

[0032] The analog-to-digital converter circuit 111 converts the analog signals provided by the voltage sensor 151 and the current sensors 32U, 32V and 32W into digital signals.

[0033] The duty cycle command value calculator 112 is a component virtually implemented in the ECU 110 by executing a program stored in memory by the CPU of the ECU 110. The duty cycle command value calculator 112 calculates the duty cycle command value for controlling the inverter 120 so that the motor generator 30 generates a driving force corresponding to the driver's operation of the accelerator of the vehicle 1, using the resolver angle shown by the signal provided from the RDC 140, the voltage VH shown by the signal from the voltage sensor 151, and the currents Iu, Iv, and Iw shown by the signals from the current sensors 32U, 32V, and 32W, and provides the calculated duty cycle command value to the inverter 120.

[0034] It is conventionally known to use grid-connected inverters to convert DC power into AC power synchronized with the AC voltage of an AC power grid. Such grid-connected inverters include an A / D port for receiving voltage sensor values ​​for synchronization with the three-phase AC voltage at the grid connection point.

[0035] However, the ECU 110 controlling the inverter 120 mounted in the aforementioned vehicle 1 typically does not include an A / D port for receiving voltage sensor values. Therefore, when attempting to convert the on-board inverter 120 into a grid-connected inverter, a new A / D port must be installed. Consequently, this conversion incurs additional costs.

[0036] When RDC 140 is not being reused, software for voltage phase calculation can be added to ECU 110, or hardware for voltage phase calculation can be configured separately. Therefore, it disadvantageously requires time and effort for software adaptation or hardware addition (adaptation of the ECU 110's control board).

[0037] Therefore, in this disclosure, the system of an inverter for grid connection application of an inverter mounted on vehicle 1 includes: an inverter 120 that converts DC power from a DC power source into AC power and supplies the AC power to an AC power line; an RDC 140 that converts a voltage value obtained by a voltage sensor into electrical angle information showing the phase angle of the output voltage, wherein the voltage sensor obtains the voltage value of the output voltage from the inverter 120 to the AC power line; and an ECU 110 that controls the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power line by using the moment when the angle shown in the electrical angle information given from the RDC 140 reaches a predetermined angle.

[0038] Therefore, it is not necessary to set up a new A / D port to receive voltage values ​​from the voltage sensor. This avoids the time and effort required to provide software or hardware to replace the RDC 140. Consequently, the additional costs, time, and effort required for conversion can be reduced.

[0039] Figure 3 This is a diagram illustrating a summary of the configuration of the system around the inverter after the application has been switched from an in-vehicle application to a grid-connected application in the first embodiment. (Refer to...) Figure 3 Due to the internal components of the PCU 10 and current sensors 32U, 32V, and 32W in systems used for grid connection applications, Figure 1 The systems shown for automotive applications are similar, so redundant descriptions will not be repeated.

[0040] Initially, in systems used for grid connection applications, except for systems used for vehicle applications, terminals 51P and 51M are located on the battery side of the boost converter 130, terminals 61U, 61V and 61W are located in the corresponding three-phase wires on the output side of the inverter 120, and terminals 72S and 72C are located in the corresponding wires of the RDC 140 for the input of sin and cos signals.

[0041] A transformer 80, which converts the voltage of inverter 120 to the voltage of power grid 90, is connected to power grid 90. On the side of transformer 80 opposite to power grid 90, a three-phase LC filter, implemented by coils 60U, 60V, and 60W and capacitors 70U, 70V, and 70W, is connected. The LC filter removes high-frequency components of the three-phase AC power from inverter 120. Terminals 61U, 61V, and 61W are connected to the opposite side of the LC filter coils 60U, 60V, and 60W of transformer 80, respectively. Voltage sensors 71U and 71V detect the voltages Vu and Vv between the opposite terminals of capacitors 70U and 70V of the LC filter, providing analog signals representing the detected voltages Vu and Vv, respectively.

[0042] In the conversion to systems used for grid connection applications, batteries 50, such as primary batteries, secondary batteries, solar cells, and fuel cells, are connected to terminals 51P and 51M. The side of coils 60U, 60V, and 60W opposite to transformer 80 is connected to terminals 61U, 61V, and 61W, and signal lines from voltage sensors 71U and 71V are connected to the corresponding terminals 72S and 72C. Instead of batteries 50, capacitors can be connected to terminals 51P and 51M.

[0043] Therefore, the voltage signals of the U phase and V phase of the three-phase AC power of the power grid 90 are provided to RDC 140 instead of the original sin and cos signals provided to RDC 140.

[0044] Figure 4 A graph showing the signal supplied when the voltages of two phases of a three-phase alternating current are provided to RDC 140 in the first embodiment is illustrated. See also Figure 4 ,like Figure 1 As shown, when the sin and cos signals from the resolver 31 of the motor generator 30 are provided to the RDC 140, it is similar to... Figure 2 The waveform of the curve in the third row of the middle is... Figure 4 The signal shown in the curve at the ideal angle is provided from RDC 140 to duty cycle command value calculator 112.

[0045] like Figure 3 As shown, when the voltage signals of phase U and phase V of the three-phase AC power from the power grid 90 are provided to RDC140, in Figure 4 The signal shown in the curve as the UV angle is provided from RDC 140 to duty cycle command value calculator 112.

[0046] When the voltage signals of phase U and phase W of the three-phase AC power from power grid 90 are supplied to RDC 140, in Figure 4 The signal shown in the curve as the UW angle is provided from RDC 140 to duty cycle command value calculator 112.

[0047] The duty cycle command value calculator 112 can detect the moment when the phase of the three-phase AC power of the power grid 90 reaches 0 degrees or ±180 degrees based on the changes in the output signal representing the UV angle or the output signal representing the UW angle. Since a period of time of one cycle can be calculated, the angular velocity of the voltage phase change can be calculated. Since the frequency of the three-phase AC power of the power grid 90 is known (e.g., 50Hz or 60Hz in Japan), the duty cycle command value calculator 112 can generate a duty cycle command value for outputting a three-phase AC power with a voltage phase synchronized with the three-phase AC power of the power grid 90, and provide this duty cycle command value to the inverter 120.

[0048] To provide such a duty cycle command value, the software used to implement the duty cycle command value calculator 112 can be modified. Specifically, the software installed in the vehicle is configured to calculate, using the resolver angle shown in the signal provided from RDC 140, the voltage VH shown in the signal from voltage sensor 151, and the currents Iu, Iv, and Iw shown in the respective signals from current sensors 32U, 32V, and 32W, to control the inverter 120 so that the motor generator 30 generates a driving force corresponding to the driver's operation of the accelerator in the vehicle 1, and provide the calculated duty cycle command value to the inverter 120.

[0049] The software installed on the vehicle with this configuration is modified to specify the moment when the three-phase AC power of the power grid 90 reaches 0 degrees or ±180 degrees by using the voltage phase angle shown in the signal provided by RDC 140, the voltage VH shown in the signal from voltage sensor 151, and the currents Iu, Iv, and Iw shown in the signals from current sensors 32U, 32V, and 32W. In order to calculate the duty cycle command value for controlling the inverter 120 to generate a three-phase AC power with the same voltage phase as the three-phase AC power of the power grid 90 synchronized with that moment, and to provide the calculated duty cycle command value to the inverter 120.

[0050] [Second Embodiment]

[0051] In the first embodiment, the conversion of the system surrounding the vehicle-mounted inverter to a system for interconnection with the three-phase AC power grid 90 is described. In the second embodiment, the conversion of the system surrounding the vehicle-mounted inverter to a system for interconnection with the single-phase AC power grids 91 and 92 will be described.

[0052] Figure 5 This is a diagram illustrating a summary of the configuration of the system around the inverter after its application has shifted from an in-vehicle application to a grid-connected application in the second embodiment. (Refer to...) Figure 5 Due to the internal components of the PCU 10 and current sensors 32U and 32W in the system used for grid connection applications, Figure 1 The systems shown for automotive applications are similar, therefore redundant descriptions will not be repeated. Since the terminals 51P, 51M, 61U, 61W, 72S, and 72C, and coils 60U and 60W, are connected to the single-phase AC grid for applications... Figure 3 The systems shown are similar to those used in the three-phase AC power grid connection application, so no further description will be repeated.

[0053] Although reference Figure 5 The single-phase alternating current of a single-phase three-wire system is described, but in Figure 5 In this context, by removing the part related to phase W and including only the part related to phase U, the single-phase AC power of a single-phase two-wire system is also applicable.

[0054] The system for single-phase AC grid connection applications is interconnected with the first phase of a single-phase three-wire system's single-phase AC power grid 91 and the second phase of a single-phase AC power grid 92 opposite to the first phase, rather than with the three-phase AC power grid 90 of a system for three-phase AC grid connection applications. Voltage sensors 93U and 93W detect the voltages Vu and Vw of power grids 91 and 92, respectively, and output analog signals representing the detected voltages Vu and Vw.

[0055] Coils 60U and 60W are connected to power grids 91 and 92 on the opposite side from ground. Coils 60U and 60W remove the high-frequency component of the alternating current from inverter 120. Terminals 61U and 61W are connected to the opposite side of coils 60U and 60W from power grids 91 and 92, respectively.

[0056] When switching to a system for grid connection applications, batteries 50, such as primary batteries, secondary batteries, solar cells, and fuel cells, are connected to terminals 51P and 51M, the sides of coils 60U and 60W opposite to the power grids 91 and 92 are connected to terminals 61U and 61W, and signal lines from voltage sensors 93U and 93W are connected to the corresponding terminals 72S and 72C.

[0057] Therefore, the voltage signals of the single-phase AC power from power grids 91 and 92 are provided to RDC 140 instead of the original sin and cos signals provided to RDC 140.

[0058] Figure 6 A graph showing the signal supplied when two single-phase alternating currents of opposite phase are supplied to RDC 140 in the second embodiment is shown. See also Figure 6 ,like Figure 1 As shown, when the sin and cos signals from the resolver 31 of the motor generator 30 are provided to the RDC 140, it is similar to... Figure 2 The waveform shown in the curve in the third row of the middle is... Figure 6 The signal shown in the curve at the ideal angle is provided from RDC 140 to duty cycle command value calculator 112.

[0059] like Figure 5 As shown, when the voltage signals of the single-phase AC power in power grids 91 and 92, which are out of phase with each other, are provided to RDC 140, in Figure 6 The signal shown in the curve as the input angle is provided from RDC 140 to duty cycle command value calculator 112.

[0060] The duty cycle command value calculator 112 can detect the moment when the phase of the single-phase AC power of power grids 91 and 92 reaches 90 degrees or -90 degrees based on this change in the signal representing the input angle. Since a period of time of one cycle can be calculated, the angular velocity of the voltage phase change can be calculated. Since the frequency of the single-phase AC power of power grids 91 and 92 is known (e.g., 50Hz or 60Hz in Japan), the duty cycle command value calculator 112 can generate a duty cycle command value for outputting a single-phase AC power with a voltage phase synchronized with the single-phase AC power of power grids 91 and 92, and provide the duty cycle command value to the inverter 120.

[0061] To provide such a duty cycle command value, the software used to implement the duty cycle command value calculator 112 can be modified. Specifically, the software installed in the vehicle is configured to calculate the duty cycle command value for controlling the inverter 120 so that the motor generator 30 generates a driving force corresponding to the driver's operation of the accelerator in the vehicle 1, using the resolver angle indicated by the signal from RDC 140, the voltage VH indicated by the signal from voltage sensor 151, and the currents Iu and Iw indicated by the signals from current sensors 32U and 32W, and provide the calculated duty cycle command value to the inverter 120.

[0062] The software installed on the vehicle with this configuration is modified to specify the moment when the single-phase AC power of power grids 91 and 92 reaches 90 degrees or -90 degrees by using the voltage phase angle shown in the signal provided by RDC 140, the voltage VH shown in the signal from voltage sensor 151, and the currents Iu and Iw shown in the signals from current sensors 32U and 32W. In order to calculate the duty cycle command value for controlling inverter 120 to generate single-phase AC power that is synchronized with that moment and has the same voltage phase as the single-phase AC power of power grids 91 or 92, the calculated duty cycle command value is provided to inverter 120.

[0063] [Variation Example]

[0064] (1) In the foregoing embodiments, such as Figure 1As shown, the motor generator 30 performs the power generation function. Alternatively, a motor without power generation function is applicable.

[0065] (2) In the foregoing embodiments, such as Figure 1 As shown, a system for converting the inverter of the motor generator 30 mounted on vehicle 1 is described. However, it is not limited to this; a system for converting the inverter of a motor mounted on a different device than vehicle 1 can also be used.

[0066] (3) In the aforementioned first embodiment, as Figure 3 As shown, signals representing the voltages Vu and Vv of the U-phase and V-phase of the three-phase alternating current are provided to RDC 140. However, the signals provided to RDC 140 may be signals representing the voltages Vv and Vw of the V-phase and W-phase of the three-phase alternating current, or signals representing the voltages Vw and Vu of the W-phase and U-phase of the three-phase alternating current.

[0067] (4) In the aforementioned second embodiment, as Figure 5 The diagram illustrates a single-phase alternating current system in a single-phase three-wire system. However, it is not limited to this; in... Figure 5 In this embodiment, by removing the part related to phase W and including only the part related to phase U, or by removing the part related to phase U and including only the part related to phase W, the second embodiment can also be applied to single-phase AC power in a single-phase two-wire system.

[0068] (5) In the previously described embodiments, such as Figure 3 and Figure 5 As shown, the interconnection to (multiple) power grids 90, 91 and / or 92 is described. However, it is not limited to this; alternating current can be supplied from inverter 120 to power lines independent of the power grids.

[0069] (6) In the previously described embodiments, such as Figure 3 and 5 As shown, an inverter 120, adapted from an in-vehicle application, is described to convert DC power in battery 50 into AC power and supply the AC power to AC power lines of power grid(s) 90, 91, and / or 92. Not limited thereto, AC power in the AC power lines can be converted into DC power by the inverter 120 adapted from an in-vehicle application, and battery 50 can be charged using the resulting DC power.

[0070] (7) The foregoing embodiments can be understood as follows: Figure 3 or Figure 5The disclosure of the interconnected inverter system shown (not only the inverter interconnected to power grids 90, 91 and / or 92, but also the inverter interconnected to power lines independent of the power grid) is to be understood as a disclosure of a method for manufacturing an interconnected inverter by converting an inverter system for vehicle applications into an interconnected inverter system, or as a disclosure of a method for interconnecting an inverter system for vehicle applications into an interconnected inverter system, or as a method for interconnecting an inverter to a power grid or an independent power line.

[0071] [Overview]

[0072] (1) As Figure 3 and Figure 5 As shown, the interconnected inverter system includes: an inverter 120 that converts DC power from a DC power source into AC power and supplies the AC power to an AC power line; an RDC 140 that converts two voltage values ​​(one voltage value in the case of a single-phase two-wire system) obtained by two voltage sensors (one voltage sensor in the case of a single-phase two-wire system) 71U and 71V or 93U and 93W into electrical angle information indicating the phase angle of the output voltage from the inverter 120 to the AC power line (e.g., power grid 90, 91, and / or 92), wherein the voltage sensors obtain two voltage values ​​of the output voltage (one voltage value in the case of a single-phase two-wire system); and an ECU 110 that controls the inverter 120 to supply AC power synchronized with the AC power flowing through the AC power line by using the time when the angle shown in the electrical angle information given by the RDC 140 reaches a predetermined angle.

[0073] Therefore, when the voltage value of the AC power in the AC power line obtained by voltage sensors 71U and 71V or 93U and 93W is provided to RDC 140, the electrical angle of the AC power and the electrical angle provided from RDC 140 are at a specific angle (e.g., Figure 4 0 degrees or 180 degrees and Figure 6 The AC power in the AC power lines (90 degrees or -90 degrees) is synchronized with each other. When the frequency (e.g., 50Hz or 60Hz) of the AC power in the AC power lines of the power grid(s) such as (multiple) power grids 90, 91 and / or 92 is known and synchronization is achieved at a specific angle, the output from inverter 120 and the AC power in the AC power lines can be synchronized with each other. Therefore, no new A / D ports are needed to receive voltage values ​​from voltage sensors 71U and 71V or 93U and 93W. This reduces the additional costs required for conversion.

[0074] (2) Figure 1 , 3 As shown in Figure 5, the inverter 120, RDC 140, and ECU 110 can be reused from the system used to drive the motor. Therefore, costs can be reduced by reusing them.

[0075] (3) Figure 1 As shown, the system used to drive the motor can be vehicle 1. Therefore, costs can be reduced by repurposing it.

[0076] (4) Figure 3 As shown, the AC power line can be a three-phase AC power line (e.g., power grid 90).

[0077] (5) Figure 3 and Figure 4 As shown, ECU 110 can control inverter 120 to provide AC power synchronized with the AC power flowing through the AC power lines by using the moment when the angle shown in the electrical angle information given from RDC 140 reaches 0 degrees or ±180 degrees. When the AC power is three-phase AC power, RDC 140 provides a synchronization signal at the moment when the electrical angle (voltage phase) of the AC power reaches 0 degrees or ±180 degrees. Therefore, precise synchronization can be achieved by using such timing.

[0078] (6) Figure 5 As shown, the AC power line can be a single-phase AC power line (e.g., power grids 91 and 92).

[0079] (7) Figure 1 , Figure 3 , Figure 5 As shown, the method of manufacturing an interconnected inverter is a method of converting RDC 140, inverter 120, and ECU 110 mounted on a system. The system includes: inverter 120, which converts DC power from a DC power source (e.g., energy storage device 20) into AC power; motor generator 30, which generates driving force using the AC power from inverter 120; resolver 31, which detects values ​​related to the rotation of motor generator 30; RDC 140, which converts the values ​​from resolver 31 into electrical angle information showing the phase angle related to the rotation; and ECU 110, which controls inverter 120 using the angle shown by the electrical angle information given from RDC 140.

[0080] A method of manufacturing interconnected inverters includes: providing terminals 51P and 51M for connection of DC power to the input of inverter 120 to a DC power source (e.g., battery 50); providing terminals 61U, 61V, and / or 61W for connection from the output of inverter 120 connected to motor generator 30 to (multiple) AC power lines (e.g., power grids 90, 91, and / or 92); providing terminals 72S and 72C for connection of signal lines from two voltage sensors (one voltage sensor in the case of a single-phase two-wire system) (e.g., voltage sensors 71U and 71V or 93U and 93W) to RDC 140, wherein the voltage sensors obtain two voltage values ​​of the output voltage to the AC power lines (one voltage value in the case of a single-phase two-wire system); and modifying the control method performed by ECU 110 to control inverter 120 to provide AC power synchronized with the AC power flowing through the AC power lines by using the moment when the angle shown in the electrical angle information given from RDC 140 reaches a predetermined angle. This configuration can reduce the additional costs required for conversion.

[0081] Although embodiments of the invention have been described, it should be understood that the embodiments disclosed herein are illustrative and not restrictive in every respect. The scope of the invention is defined by the terminology of the claims and is intended to include any modifications within the scope and meaning of the equivalent terms of the claims.

Claims

1. Interconnected inverters, including: An inverter circuit converts DC power from a DC power source into AC power and supplies the AC power to the AC power line; A rotary transformer digital converter that converts a voltage value obtained by a voltage sensor into electrical angle information showing the phase angle of the output voltage from the inverter circuit to the AC power line, wherein the voltage sensor obtains the voltage value of the output voltage; as well as The control unit controls the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power line by using the time when the angle shown in the electrical angle information given from the rotary transformer digital converter reaches a predetermined angle.

2. The interconnected inverter according to claim 1, wherein, The inverter circuit, the resolver-to-digital converter, and the control unit are switched from the system used to drive the motor.

3. The interconnected inverter according to claim 2, wherein, The system used to drive the motor is a vehicle.

4. The interconnected inverter according to any one of claims 1 to 3, wherein, The AC power line is a three-phase AC power line.

5. The interconnected inverter according to any one of claims 1 to 3, wherein, The control unit controls the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power lines at the moment when the angle shown in the electrical angle information given from the resolver digital converter reaches 0 degrees or ±180 degrees.

6. The interconnected inverter according to any one of claims 1 to 3, wherein, The AC power line is a single-phase AC power line.

7. A method for manufacturing an interconnected inverter, the method being a means of converting a resolver-to-digital converter, an inverter circuit, and a control unit mounted on a system, the system comprising: An inverter circuit converts DC power from a DC power source into AC power. The motor generates driving force using AC power from the inverter circuit. A rotary transformer that detects values ​​related to the rotation of the motor. A resolver-to-digital converter that converts values ​​from the resolver into electrical angle information showing the phase angle associated with rotation, and The control unit controls the inverter circuit using the angle shown in the electrical angle information given by the rotary transformer digital converter. The method includes: Provides terminals for connecting DC power to the input of DC power to the inverter; A terminal is provided for connecting the output of the inverter circuit connected to the motor to an AC power line; Terminals are provided for connecting a signal line from a voltage sensor to the digital converter of the resolver, the voltage sensor obtaining the voltage value of the output voltage to the AC power line; and The control method of the control unit is modified to control the inverter circuit to provide AC power synchronized with the AC power flowing through the AC power line at the moment when the angle shown in the electrical angle information given from the rotary transformer digital converter reaches a predetermined angle.

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