Inverter device, electric power assembly system and vehicle

Abstract

Disclosed are an inverter device, an electric power assembly system, and a vehicle, the inverter device being configured to invert an input direct current and output a single-phase alternating current, and the inverter device comprising: a safety capacitor including a first safety capacitor disposed between a live wire output end and a ground wire of the single-phase alternating current, and a second safety capacitor disposed between the live wire output end and the ground wire of the single-phase alternating current, the safety capacitor including a second safety capacitor disposed between the live wire output end and the ground wire of the single-phase alternating current; the second safety capacitor is arranged between the zero line output end of the single-phase alternating current and a ground wire, and the first safety capacitor is the same as the second safety capacitor; wherein each of the first safety capacitor and the second safety capacitor is formed by a first sub-capacitor and a second sub-capacitor.

Description

Technical Field

[0001] The present invention relates to the field of power control, and more particularly to an inverter device, a power assembly system and a vehicle. Background Art

[0002] With the widespread application of inverter devices in civil and commercial fields, the settings of inverter devices are also facing higher requirements.

[0003] Current inverter devices are designed to invert input DC power and output single-phase AC power, and typically include safety capacitors arranged between the live output terminal and the ground wire, and between the neutral output terminal and the ground wire, of the single-phase AC power. Such safety capacitors are intended to suppress common-mode interference with the power grid. However, current safety capacitors are typically formed by a single type of capacitor, such as only chip-type multilayer ceramic capacitors, or only thin-film capacitors. This means that when the inverter device is subjected to insulation impedance testing, due to the impedance detection principle, the voltage detected during the impedance detection process is correlated with the voltage on the safety capacitor. Current safety capacitors are only composed of a single type of capacitor. During the impedance detection process, due to the large leakage current of the capacitor, the impedance of the safety capacitor drifts, and the collected detection voltage is unstable, affecting the accuracy of the inverter's impedance detection, and may even result in erroneous impedance detection results.

[0004] Therefore, there is a need for a method that can effectively reduce the leakage current of the safety capacitor in the inverter device and reduce the impedance drift of the safety capacitor while achieving a good inversion function of the inverter device, thereby improving the accuracy and reliability of the impedance detection of the inverter. Summary of the Invention

[0005] To address the above issues, the present invention provides an inverter device, power assembly system, and vehicle. The inverter device provided by the present invention can achieve a smooth DC to AC conversion process while reducing leakage current and impedance drift in the safety capacitors within the inverter device. This also improves the accuracy and reliability of the inverter's impedance detection process.

[0006] According to one aspect of the present invention, an inverter device is provided, wherein the inverter device is configured to invert input direct current and output single-phase alternating current, and the inverter device includes: safety capacitors, including a first safety capacitor arranged between a live wire output terminal of the single-phase alternating current and a ground wire, and a second safety capacitor arranged between a neutral wire output terminal of the single-phase alternating current and the ground wire, wherein the first safety capacitor is identical to the second safety capacitor; wherein each of the first safety capacitor and the second safety capacitor is formed by a first sub-capacitor and a second sub-capacitor.

[0007] In some embodiments, the first sub-capacitor is a chip-type multilayer ceramic capacitor.

[0008] In some embodiments, the second sub-capacitor is a thin film capacitor.

[0009] In some embodiments, the first sub-capacitor and the second sub-capacitor are connected in parallel.

[0010] In some embodiments, the first sub-capacitor and the second sub-capacitor are connected in series.

[0011] In some embodiments, the first safety capacitor and the second safety capacitor each include a thin film capacitor and a chip multilayer ceramic capacitor.

[0012] In some embodiments, for each of the first safety capacitor and the second safety capacitor, the capacitance value of the chip multilayer ceramic capacitor is less than 25nF, the capacitance value of the thin film capacitor is less than 25nF, and the sum of the capacitance values ​​of the chip multilayer ceramic capacitor and the thin film capacitor is less than 50nF.

[0013] In some embodiments, the inverter device further includes an insulation impedance detection circuit configured to detect a performance status of insulation impedance between the live output terminal and the ground line, and between the neutral output terminal and the ground line.

[0014] In some embodiments, the insulation impedance detection circuit includes: a sampling subcircuit, which is configured to sample the voltage signals between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire, to obtain an AC sampling signal; a precision rectifier subcircuit, which is configured to convert the AC sampling signal into a DC signal; a low-pass filter subcircuit, which is configured to filter the DC signal to obtain a DC filtered signal; and a central processing subcircuit, which is configured to determine the performance status of the insulation impedance in the inverter device based on the DC filtered signals from between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire.

[0015] In some embodiments, the central processing subcircuit is configured to: calculate the signal difference of the DC filtered signal between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire; compare the signal difference with a preset difference range, and determine the performance status of the insulation impedance in the inverter device based on the comparison result.

[0016] According to another aspect of the present disclosure, a power assembly system is provided, comprising the inverter device as described above.

[0017] According to another aspect of the present disclosure, a vehicle is provided, comprising the above-mentioned electric powertrain system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. A person skilled in the art can derive other drawings based on these drawings without inventive effort. The following drawings are not intentionally scaled to actual size; their focus is on illustrating the main points of the present invention.

[0019] Figure 1 1 shows a schematic diagram of an inverter device 100 according to an embodiment of the present disclosure;

[0020] Figure 2 A schematic diagram showing the principle of insulation impedance detection of an inverter device according to an embodiment of the present disclosure is shown;

[0021] Figure 3 A schematic diagram showing a parallel arrangement of sub-capacitors according to an embodiment of the present disclosure is shown;

[0022] Figure 4 shows a schematic diagram of sub-capacitors arranged in series according to an embodiment of the present disclosure;

[0023] Figure 5 1 shows a schematic diagram of an insulation impedance detection circuit 200 according to an embodiment of the present disclosure;

[0024] Figure 6 A schematic diagram of a digital voltage of a detection voltage obtained by insulation impedance detection according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts also fall within the scope of protection of the present invention.

[0026] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0027] Although the present application makes various references to certain modules in the system according to embodiments of the present application, any number of different modules can be used and run on the user terminal and / or server. The modules are illustrative only, and different aspects of the system and method can use different modules.

[0028] Flowcharts are used in this application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously, as needed. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0029] It should be understood that the current inverter device is designed to achieve the process of inverting the input direct current and outputting single-phase alternating current, and generally includes safety capacitors arranged between the live wire output terminal and the ground wire and between the neutral wire output terminal and the ground wire of the single-phase alternating current. Such safety capacitors are intended to suppress common-mode interference to the power grid. However, the current safety capacitors are generally formed by a single type of capacitor, for example, only by chip multilayer ceramic capacitors, or only by film capacitors. This means that when the inverter device is subjected to insulation impedance testing, due to the impedance detection principle, the voltage detected during the impedance detection process is associated with the voltage on the safety capacitor (the specific correlation will be explained below in conjunction with the impedance detection circuit and the impedance detection principle). The current safety capacitors are only composed of a single type of capacitor. During the impedance detection process, due to the large leakage current of the capacitor, the impedance drift of the safety capacitor causes the collected detection voltage to be unstable, affecting the accuracy of the inverter's impedance detection, and may even obtain erroneous impedance detection results.

[0030] Based on the above, according to one aspect of the present disclosure, an inverter device 100 is provided. The inverter device 100 is configured to invert input direct current and output single-phase alternating current. Figure 1 FIG2 shows a schematic diagram of an inverter device 100 according to an embodiment of the present disclosure.

[0031] Reference Figure 1 For example, the inverter device includes an inverter circuit 110 for converting direct current into alternating current. The inverter circuit 110 may be a single-phase full-bridge inverter circuit or a single-phase half-bridge inverter circuit. It should be understood that the embodiments of the present disclosure are not limited by the inverter circuit or specific inverter implementation of the inverter.

[0032] The inverter device 100 also includes: safety capacitors, including a first safety capacitor 121 arranged between the live wire output terminal L of the single-phase alternating current and the ground wire GND, and a second safety capacitor 122 arranged between the neutral wire output terminal N of the single-phase alternating current and the ground wire GND, wherein the first safety capacitor 121 is the same as the second safety capacitor 122.

[0033] It should be understood that the safety capacitor, also known as Y safety capacitor or Y capacitor, is a capacitor connected between the phase line (such as the neutral line or the live line) and the ground line. It is used to filter out common-mode interference on the power line, thereby reducing the damage to the equipment caused by lightning strikes and surges.

[0034] It should be understood that the inverter device further includes, for example, an insulating material (e.g., having an equivalent insulation impedance Z_XL) disposed between the live output terminal L and the ground line GND, and an insulating material (e.g., having an equivalent insulation impedance Z_XN) disposed between the single-phase AC neutral output terminal N and the ground line GND, to achieve good insulation between the neutral, live, and ground lines to prevent breakdown. It should be understood that the embodiments of the present disclosure are not limited by the specific composition of the insulating material or the specific value of the corresponding insulation impedance.

[0035] Furthermore, during insulation impedance testing of inverters, for example, the performance characteristics of safety capacitors can significantly impact the test results. Insulation impedance testing of inverters is performed to verify that the insulation within the inverter meets standard requirements, thereby ensuring the safety of the inverter during long-term use.

[0036] Figure 2 A schematic diagram showing the principle of insulation impedance detection of an inverter device according to an embodiment of the present disclosure is shown.

[0037] Reference Figure 2 When performing insulation impedance testing on the inverter device, for example, the live wire detection voltage V that can reflect the voltage value between the live wire output terminal L and the ground wire GND is collected. L_GND , and collect the zero line detection voltage V that can reflect the voltage value between the zero line output terminal N and the ground line GND N_GND , and perform differential calculation based on the live line detection voltage and the neutral line detection voltage to determine the insulation impedance of the inverter device. Specifically, Figure 2 As shown, for example, the voltage between the live wire output terminal L and the ground wire GND can be divided by the resistor R1 and the resistor R2, and the voltage across the resistor R2 can be detected as the live wire detection voltage V L_GND The voltage between the single-phase AC zero line output terminal N and the ground line GND is divided by resistors R3 and R4, and the voltage across the resistor R4 is detected as the zero line detection voltage VN_GND .

[0038] For example, when the insulation impedance of the inverter device is normal, the live wire detection voltage and the neutral wire detection voltage should be basically equal; when the insulation impedance of the inverter device is abnormal, for example, when the insulating material between the live wire output terminal L and the ground wire GND is damaged or broken down, the difference between the live wire detection voltage and the neutral wire detection voltage will increase significantly, thereby determining that there is an abnormal insulation impedance.

[0039] As mentioned above, the collected live wire detection voltage V L_GND The collected neutral line detection voltage V N_GND The voltage is significantly affected by the capacitance impedance of the second safety capacitor 122 provided between the neutral line output terminal N of the single-phase AC power and the ground line GND.

[0040] The first safety capacitor and the second safety capacitor are each formed by a first sub-capacitor and a second sub-capacitor.

[0041] It should be understood that the first sub-capacitor and the second sub-capacitor refer to two different types of capacitors. For example, the first sub-capacitor may be a ceramic capacitor, and the second sub-capacitor may be a film capacitor, which is different from a ceramic capacitor. It should be understood that the embodiments of the present disclosure are not limited by the specific types of the first and second sub-capacitors.

[0042] Based on the above, in the present application, an inverter device is provided that includes a first safety capacitor disposed between the live output terminal of the single-phase AC power and the ground line, and a second safety capacitor identical to the first safety capacitor disposed between the neutral output terminal of the single-phase AC power and the ground line. Furthermore, each of the first safety capacitor and the second safety capacitor is formed from a first sub-capacitor and a second sub-capacitor. Compared to the current situation in which a safety capacitor is formed using only a single capacitor (such as a chip multilayer ceramic capacitor or a film capacitor), the safety capacitor is formed from different sub-capacitors (first and second sub-capacitors). This allows for the characteristics of different types of capacitors to be well absorbed and the performance deficiencies of a single capacitor to be compensated for, thereby advantageously improving the current undesirable conditions of large leakage current and high impedance drift of safety capacitors. While also taking into account the common-mode suppression function of the safety capacitor, the performance of the safety capacitor in impedance detection of the inverter device is further considered and taken into account. This allows for improved accuracy and reliability of impedance detection of the inverter device while achieving a good inverter function.

[0043] In some embodiments, the first sub-capacitor C1 is a chip-type multilayer ceramic capacitor.

[0044] Multi-layer ceramic capacitors (MLCCs) are made by stacking ceramic dielectric diaphragms with printed electrodes (inner electrodes) in an offset manner. After a one-time high-temperature sintering process, a ceramic chip is formed. A metal layer (outer electrode) is then sealed at both ends of the chip to form a structure similar to a monolithic structure, hence the name monolithic capacitor.

[0045] For example, chip-type multilayer ceramic capacitors have the following characteristics: First, due to their structure of stacked dielectric layers, they have very low inductance at high frequencies, very low equivalent series resistance, and low impedance. Second, they do not burn or explode upon breakdown, providing high safety.

[0046] Based on the above, in this application, by setting the first sub-capacitor as a chip multilayer ceramic capacitor, the safety capacitor formed can effectively absorb the better capacitance characteristics of the chip multilayer ceramic capacitor, and on the basis of achieving good inverter performance of the inverter device, effectively reduce the leakage current of the safety capacitor and reduce impedance drift.

[0047] In some embodiments, the second sub-capacitor C2 is a thin film capacitor.

[0048] Film capacitors, also known as plastic film capacitors, use metal foil as electrodes and plastic films such as polyethylene, polypropylene, polystyrene or polycarbonate overlapped at both ends and wound into a cylindrical structure.

[0049] Depending on the type of plastic film, they are also known as polyethylene capacitors (also known as polyester capacitors), polypropylene capacitors (also known as PP capacitors), polystyrene capacitors (also known as PS capacitors), and polycarbonate capacitors. It should be understood that the embodiments of the present disclosure are not limited to the specific type of film capacitor.

[0050] For example, film capacitors have the following characteristics: First, film capacitors have extremely high precision and can meet the precision requirements of various applications. Its manufacturing process is highly precise, and capacitors with small tolerances and good stability can be made. Secondly, the capacitance value of film capacitors is stable, and its stability is better than that of ceramic capacitors and aluminum electrolytic capacitors. Moreover, the temperature drift of film capacitors is small, and there will be no significant change in capacitance value due to temperature changes. Thirdly, film capacitors are small in size and light in weight, making them suitable for manufacturing miniaturized products. In addition, film capacitors have a long service life, which can reach decades or even longer under correct conditions of use. In addition, film capacitors have strong resistance to vibration and impact, and can work normally even in harsh environments.

[0051] Based on the above, in this application, by setting the second sub-capacitor as a thin film capacitor, the safety capacitor formed can effectively absorb the better capacitance characteristics of the thin film capacitor, and on the basis of achieving good inversion performance of the inverter device, effectively reduce the leakage current of the safety capacitor and reduce impedance drift.

[0052] In some embodiments, the first sub-capacitor C1 and the second sub-capacitor C2 are connected in parallel. Figure 3 A schematic diagram of sub-capacitors connected in parallel according to an embodiment of the present disclosure is shown.

[0053] Reference Figure 3 By connecting the first sub-capacitor C1 and the second sub-capacitor C2 in parallel, on the one hand, the equivalent capacitance of the resulting safety capacitor (e.g., the first safety capacitor and the second safety capacitor) is equal to the sum of the capacitance of the first sub-capacitor C1 and the capacitance of the second sub-capacitor C2, thereby increasing the capacitance of the resulting safety capacitor. On the other hand, connecting the first sub-capacitor C1 and the second sub-capacitor C2 in parallel to form a safety capacitor also allows the resulting safety capacitor to absorb and possess the good characteristics of the two different sub-capacitors, thereby reducing leakage current and impedance drift in the safety capacitor.

[0054] In some embodiments, the first sub-capacitor C1 and the second sub-capacitor C2 are connected in series. Figure 4 A schematic diagram showing sub-capacitors arranged in series according to an embodiment of the present disclosure is shown.

[0055] Reference Figure 4By connecting the first sub-capacitor C1 and the second sub-capacitor C2 in series, on the one hand, the capacitance value of the resulting safety capacitor (e.g., the first safety capacitor and the second safety capacitor) is made the reciprocal of the sum of the reciprocal of the capacitance value of the first sub-capacitor C1 and the reciprocal of the capacitance value of the second sub-capacitor C2, thereby reducing the capacitance value of the resulting safety capacitor. On the other hand, connecting the first sub-capacitor C1 and the second sub-capacitor C2 in series to form a safety capacitor also allows the formed safety capacitor to absorb and possess the good characteristics of the two different sub-capacitors, thereby facilitating the reduction of leakage current in the safety capacitor and reducing impedance drift.

[0056] In some embodiments, the first safety capacitor and the second safety capacitor each include a thin film capacitor and a chip multilayer ceramic capacitor.

[0057] By configuring the first safety capacitor and the second safety capacitor to each include a thin film capacitor and a chip multilayer ceramic capacitor, the first safety capacitor can simultaneously absorb and possess the favorable characteristics of the aforementioned thin film capacitor and chip multilayer ceramic capacitor, thereby facilitating the reduction of leakage current of the safety capacitor and impedance drift. Furthermore, by flexibly configuring the capacitance composition of the thin film capacitor and chip multilayer ceramic capacitor, multiple aspects such as manufacturing cost, safety capacitor performance, and insulation impedance detection accuracy can be balanced.

[0058] In some embodiments, for each of the first safety capacitor 121 and the second safety capacitor 122, the capacitance value of the chip multilayer ceramic capacitor is less than 25nF, the capacitance value of the thin film capacitor is less than 25nF, and the sum of the capacitance values ​​of the chip multilayer ceramic capacitor and the thin film capacitor is less than 50nF.

[0059] It should be understood that the sum of the capacitance of the chip multilayer ceramic capacitor and the capacitance of the film capacitor is calculated differently depending on the connection relationship between the two. For example, when the chip multilayer ceramic capacitor and the film capacitor are connected in parallel, the sum of the capacitance of the chip multilayer ceramic capacitor and the capacitance of the film capacitor is the sum of the capacitance of the chip multilayer ceramic capacitor and the capacitance of the film capacitor. When the chip multilayer ceramic capacitor and the film capacitor are connected in series, the sum of the capacitance of the chip multilayer ceramic capacitor and the capacitance of the film capacitor is the reciprocal of the sum of the reciprocals of the series capacitances.

[0060] For example, according to actual needs, a chip-type multilayer ceramic capacitor with a smaller capacitance value can be set, and a film capacitor with a larger capacitance value can be selected to reduce manufacturing costs (the manufacturing cost of chip-type multilayer ceramic capacitors is relatively high, and choosing a small capacitance value is more conducive to reducing volume and reducing costs).

[0061] For example, when the chip multilayer ceramic capacitor is connected in parallel with the thin film capacitor, the capacitance value of the chip multilayer ceramic capacitor can be set to 4.7nF, and the capacitance value of the thin film capacitor can be set to 8.2nF. When the chip multilayer ceramic capacitor is connected in series with the thin film capacitor, the capacitance value of the chip multilayer ceramic capacitor can be set to 7.4nF, and the capacitance value of the thin film capacitor can be set to 8.2nF. However, it should be understood that the above only gives an example of setting the capacitance value of the chip multilayer ceramic capacitor and the thin film capacitor. The embodiments of the present disclosure are not limited to the specific values ​​of the capacitance value of the chip multilayer ceramic capacitor and the capacitance value of the thin film capacitor.

[0062] Based on the above, in this application, by setting the sum of the capacitance value of the chip multilayer ceramic capacitor and the capacitance value of the thin film capacitor to be less than 50nF, the current value of the touch current flowing through the safety capacitor can meet the preset standard requirements, for example, less than 3.4mA (the Chinese national standard requires less than 3.4mA), so that the current flowing through the safety capacitor can be maintained within a smaller range while ensuring the good use of the safety capacitor, which is beneficial to improving the safety and reliability of the capacitor.

[0063] In some embodiments, the inverter device 100 further includes an insulation impedance detection circuit 200 , which is configured to detect the performance status of the insulation impedance between the live output terminal L and the ground wire GND, and between the neutral output terminal N and the ground wire GND.

[0064] It should be understood that, as described above, the insulation impedance is, for example, the equivalent impedance of the corresponding insulating material. Specifically, the inverter device also includes, for example, an insulating material disposed between the live output terminal L and the ground line GND (which, for example, has an equivalent insulation impedance Z_XL), and an insulating material disposed between the single-phase AC neutral output terminal N and the ground line GND (which, for example, has an equivalent insulation impedance Z_XN), to achieve good insulation between the neutral line, the live line, and the ground line to prevent breakdown. It should be understood that the embodiments of the present disclosure are not limited by the specific composition of the insulating material and the specific resistance value of the corresponding insulation impedance.

[0065] The performance state of the insulation impedance is intended to characterize the current performance of the insulation impedance (i.e., the corresponding insulation material), and includes, for example, a normal performance state and an abnormal performance state. A normal performance state refers to the insulation impedance being at a normal resistance value, i.e., indicating that the insulation material corresponding to the insulation impedance is in a good insulation state. An abnormal performance state refers to the insulation impedance being at a resistance level significantly lower than the normal resistance value, i.e., indicating that the insulation material corresponding to the insulation impedance is damaged, or that there is leakage in the inverter device circuit.

[0066] It should be understood that, according to actual needs, the insulation impedance detection circuit may have, for example, different component sub-circuits. The embodiments of the present disclosure are not limited by the specific components of the insulation impedance detection circuit.

[0067] It should be understood that, depending on actual needs, the insulation impedance detection circuit can be, for example, a single-ended detection circuit, that is, capable of performing a good detection only when the insulation impedance between the live output terminal L and the ground wire GND, or the insulation impedance between the neutral output terminal N and the ground wire GND, exhibits an abnormal performance state. However, it should be understood that the embodiments of the present disclosure are not limited thereto.

[0068] Based on the above, in this application, the inverter device is further configured to include an insulation impedance detection circuit 200, and the insulation impedance detection circuit 200 is configured to detect the performance status of the insulation impedance between the live wire output terminal L and the ground wire GND, and between the neutral wire output terminal N and the ground wire GND, so that the insulation impedance performance of the inverter device can be reliably detected through the insulation impedance detection circuit, which is conducive to timely detection of insulation damage or leakage, and improves the reliability and safety of the inverter device.

[0069] In some embodiments, the insulation impedance detection circuit 200 can be described in more detail, for example. Figure 5 FIG. 2 shows a schematic diagram of an insulation resistance detection circuit 200 according to an embodiment of the present disclosure.

[0070] Reference Figure 5 The insulation impedance detection circuit 200 includes: a sampling sub-circuit 210, a precision rectifier sub-circuit 220, a low-pass filter sub-circuit 230 and a central processing sub-circuit 240.

[0071] The sampling subcircuit 210 is configured to sample the voltage signals between the live line output terminal L and the ground line GND, and between the neutral line output terminal N and the ground line GND, to obtain AC sampling signals.

[0072] The AC sampling signal refers to an AC voltage signal obtained by sampling the voltage signals between the live line output terminal L and the ground line GND, and between the neutral line output terminal N and the ground line GND.

[0073] It should be understood that, for example, it can directly sample the voltage between the live output terminal L and the ground line GND, and between the neutral output terminal N and the ground line GND, or it can also be based on the aforementioned Figure 2 , the voltage between the live wire output terminal L and the ground wire GND, and the voltage between the neutral wire output terminal N and the ground wire GND are divided by resistors, and the voltage on some resistors is collected, so that the collected voltage can better reflect the change in insulation impedance, and the collected voltage value can be much smaller than the voltage between the live wire output terminal L and the ground wire GND, and the voltage between the neutral wire output terminal N and the ground wire GND, for example, the voltage value of the sampled voltage is set below 5V, which is convenient for subsequent further processing.

[0074] However, it should be understood that the above is only an example, and the embodiments of the present disclosure are not limited by the specific sampling method for obtaining the AC sampling signal and the voltage value of the AC sampling signal.

[0075] The precision rectifier circuit 220 is configured to convert the AC sampling signal into a DC signal.

[0076] A precision rectifier circuit is a circuit used to convert an AC signal into a high-precision DC signal. Depending on actual needs, it can be, for example, a half-wave rectifier circuit or a full-wave rectifier circuit. The embodiments of the present disclosure are not limited by the specific composition of the precision rectifier circuit.

[0077] The low-pass filter subcircuit 230 is configured to filter the DC signal to obtain a DC filtered signal.

[0078] The low-pass filter subcircuit is a frequency-selective circuit that can be used to filter or reduce high-frequency signal components while transmitting or enhancing low-frequency signal components. That is, the low-frequency signal components in the input DC signal are transmitted to the output end with less loss, so that the high-frequency signal components in the DC signal are effectively suppressed.

[0079] The DC filtered signal refers to a DC signal output after low-pass filtering, in which the high-frequency signal component is significantly reduced while the low-frequency signal component is well preserved.

[0080] It should be understood that, depending on actual needs, the low-pass filter subcircuit may be, for example, an active filter circuit (eg, composed of an RC network and an integrated operational amplifier), or a passive filter circuit. The embodiments of the present disclosure are not limited thereto.

[0081] The central processing sub-circuit 240 is configured to determine the performance status of the insulation impedance in the inverter device based on the DC filtered signals from between the live output terminal L and the ground line GND, and between the neutral output terminal N and the ground line GND.

[0082] It should be understood that the central processing sub-circuit can, for example, calculate the signal difference of the DC filtered signal between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire; compare the signal difference with a preset difference range, and determine the performance status of the insulation impedance in the inverter device based on the comparison result.

[0083] However, it should be understood that the above is only an example of a performance status determination method, and the embodiments of the present disclosure are not limited thereto.

[0084] Based on the above, in this application, the insulation impedance detection circuit is set to include: a sampling sub-circuit, a precision rectifier sub-circuit, a low-pass filter sub-circuit and a central processing sub-circuit, so that the insulation detection process of the inverter device can be well implemented based on the cooperation of each sub-circuit, thereby timely and accurately discovering the insulation condition of the inverter device and performing corresponding processing.

[0085] In some embodiments, the central processing sub-circuit 240 is configured to: first, calculate the signal difference of the DC filtered signal between the live wire output terminal L and the ground wire GND, and between the neutral wire output terminal N and the ground wire GND; then, compare the signal difference with a preset difference range, and based on the comparison result, determine the performance status of the insulation impedance in the inverter device.

[0086] It should be understood that the signal difference can be, for example, the absolute value of the difference between the voltage value of the DC filtered signal between the live wire output terminal L and the ground wire GND and the voltage value of the DC filtered signal between the neutral wire output terminal N and the ground wire GND.

[0087] It should be understood that the preset difference range can be, for example, a pre-set reasonable difference range, which represents the difference range between the voltage value of the DC filtered signal of the voltage between the live wire output terminal L and the ground wire GND and the voltage value of the DC filtered signal between the neutral wire output terminal N and the ground wire GND under normal circumstances. Exceeding the preset difference range indicates the existence of an abnormal impedance state.

[0088] The process of determining the performance status of the insulation impedance of the inverter device based on the comparison result can be described in more detail, for example, by determining whether the currently obtained signal difference falls within a preset difference range. If the difference signal falls within the preset difference range, the insulation impedance of the inverter device is determined to be in a normal performance state; if the difference signal does not fall within the preset difference range, the insulation impedance of the inverter device is determined to be in an abnormal performance state. Alternatively, the difference signal can be further analyzed to determine whether the impedance between the live output terminal L and the ground wire GND is in an abnormal performance state, or whether the impedance between the neutral output terminal N and the ground wire GND is in an abnormal performance state.

[0089] It should be understood that the present disclosure is not limited by the specific form of the performance status determination process and the determination output result.

[0090] Based on the above, in the present application, the central processing sub-circuit is set to calculate the signal difference of the DC filter signal between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire; the signal difference is compared with a preset difference range, and based on the comparison result, the performance status of the insulation impedance in the inverter device is determined, so that a good and reliable judgment of the performance status of the insulation impedance in the inverter device can be achieved in a simple and convenient manner.

[0091] Next, the inverter device will be described in more detail in combination with specific application scenarios. Figure 2 , when the insulation impedance detection circuit 200 is used to detect the insulation impedance of the inverter device, the first and second safety capacitors of the inverter device are configured to include a chip multilayer ceramic capacitor and the film capacitor connected in parallel, and the capacitance value of the chip multilayer ceramic capacitor is set to 4.7nF and the capacitance value of the film capacitor is set to 8.2nF. Figure 6 A schematic diagram of the digital voltage of the detection voltage obtained by insulation resistance detection is shown, where the horizontal axis is time (for example, in ms), and the vertical axis is the voltage digital output obtained after sampling and processing the voltage signal and converting it at the analog / digital converter (AD) of the central processing subcircuit. The unit is the least significant bit (LSB), and the voltage digital output is proportional to the voltage value of the sampled voltage.

[0092] Reference Figure 6It can be seen that the voltage across the detection resistor (for example, the detection resistor R2) is basically stable at this time, which also reflects that the capacitor voltage across the safety capacitor is basically stable. It can also be seen that the voltage digital drift of the detection resistor is within the range of less than 30LSB. Compared with the current safety capacitor formed by only a single type of sub-capacitor (the voltage digital drift of its detection resistor is usually hundreds of LSBs or several hundred LSBs), the change of the equivalent capacitive reactance of the safety capacitor has been significantly improved.

[0093] According to another aspect of the present disclosure, a power assembly system is proposed, including the inverter device as described above, and capable of realizing the functions described above, which will not be described in detail here.

[0094] According to another aspect of the present disclosure, a vehicle is provided, comprising the power assembly system as described above, and having the inverter device as described above, capable of realizing the functions described above.

[0095] For example, when the vehicle is in inverter mode (in which the vehicle serves as a charging power source to charge external devices), the inverter device in the power assembly system can be used to achieve good and reliable external charging.

[0096] The program portion of the technology can be considered a "product" or "article of manufacture" in the form of executable code and / or related data, implemented or implemented through computer-readable media. Tangible, permanent storage media can include any memory or storage used by a computer, processor, or similar device or related module. For example, various semiconductor memories, tape drives, disk drives, or any similar device that can provide storage for software.

[0097] All or part of the software may sometimes be communicated over a network, such as the Internet or other communications network. Such communication can load software from one computer device or processor to another. For example: from a server or host computer of a target tracking device to a hardware platform of a computer environment, or other computer environment that implements the system, or a system with similar functions related to providing the required information. Therefore, another medium capable of transmitting software elements can also be used as a physical connection between local devices, such as light waves, radio waves, electromagnetic waves, etc., transmitted through cables, optical cables or air. Physical media used to carry carriers, such as cables, wireless connections or optical cables and the like, can also be considered as media that carry software. As used herein, unless limited to tangible "storage" media, other terms referring to computer or machine "readable media" refer to media that participate in the process of executing any instructions by the processor.

[0098] This application uses specific terms to describe the embodiments of this application. For example, "first / second embodiment", "one embodiment", and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different places in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0099] In addition, it will be understood by those skilled in the art that various aspects of the present application can be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0100] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or highly formal sense, unless expressly defined as such herein.

[0101] The above is an illustration of the present invention and should not be considered as limiting thereof. Although several exemplary embodiments of the present invention have been described, it will be readily understood by those skilled in the art that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present invention. Therefore, all such modifications are intended to be included within the scope of the present invention as defined by the claims. It should be understood that the above is an illustration of the present invention and should not be considered as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present invention is defined by the claims and their equivalents.

Claims

1. An inverter device, wherein: The inverter device is configured to invert input direct current and output single-phase alternating current, and the inverter device includes: A safety capacitor, comprising a first safety capacitor disposed between the live wire output terminal of the single-phase alternating current and the ground wire, and a second safety capacitor disposed between the neutral wire output terminal of the single-phase alternating current and the ground wire, wherein the first safety capacitor is identical to the second safety capacitor; The first safety capacitor and the second safety capacitor are each formed by a first sub-capacitor and a second sub-capacitor.

2. The inverter device according to claim 1, wherein: The first sub-capacitor is a chip-type multilayer ceramic capacitor.

3. The inverter device according to claim 1 or 2, wherein: The second sub-capacitor is a thin film capacitor.

4. The inverter device according to claim 1, wherein: The first sub-capacitor and the second sub-capacitor are connected in parallel.

5. The inverter device according to claim 1, wherein: The first sub-capacitor and the second sub-capacitor are connected in series.

6. The inverter device according to claim 1, wherein: Each of the first safety capacitor and the second safety capacitor includes a film capacitor and a chip-type multilayer ceramic capacitor.

7. The inverter device according to claim 6, wherein: For each of the first safety capacitor and the second safety capacitor, the capacitance value of the chip multilayer ceramic capacitor is less than 25nF, the capacitance value of the film capacitor is less than 25nF, and the sum of the capacitance values ​​of the chip multilayer ceramic capacitor and the film capacitor is less than 50nF.

8. The inverter device according to claim 1, wherein: The inverter device further includes an insulation impedance detection circuit configured to detect a performance status of insulation impedance between the live output terminal and the ground line, and between the neutral output terminal and the ground line.

9. The inverter device according to claim 8, wherein: The insulation impedance detection circuit comprises: a sampling subcircuit configured to sample voltage signals between the live output terminal and the ground wire, and between the neutral output terminal and the ground wire, to obtain alternating current sampling signals; a precision rectifier circuit configured to convert the AC sampling signal into a DC signal; a low-pass filter subcircuit, configured to filter the DC signal to obtain a DC filtered signal; The central processing subcircuit is configured to determine the performance status of the insulation impedance in the inverter device based on the DC filtered signals between the live output terminal and the ground line and between the neutral output terminal and the ground line.

10. The inverter device according to claim 9, wherein: The central processing subcircuit is configured to: Calculating a signal difference between the DC filtered signal between the live wire output terminal and the ground wire, and between the neutral wire output terminal and the ground wire; The signal difference is compared with a preset difference range, and based on the comparison result, the performance status of the insulation impedance in the inverter device is determined.

11. An electric power assembly system comprising the inverter device according to any one of claims 1 to 10.

12. A vehicle comprising the electric powertrain system according to claim 11.

Images