Inverter for electric compressor and electric compressor employing same

Abstract

The present invention relates to an inverter for an electric compressor and an electric compressor employing same, and more specifically, to an inverter for an electric compressor, the inverter including a circuit board divided into a high voltage region and a low voltage region. The inverter comprises: a switching element for controlling the switching of a motor of the electric compressor; and an MCU for controlling the switching element, wherein the switching element is disposed in the high voltage region, the MCU is disposed in the low voltage region, various sensors are provided in the high voltage region, an intermediate element is provided between the various sensors and the MCU, and the intermediate element includes an operational amplifier.

Description

Inverter for electric compressor and electric compressor employing the same

[0001] The present invention relates to an inverter for an electric compressor and an electric compressor employing the inverter.

[0002]

[0003] Typically, vehicles use an electric compressor that pumps out refrigerant using the rotational power of an electric motor that uses power charged in a battery.

[0004] The electric compressor is composed of a motor section including a drive motor and a compression section that compresses refrigerant, and an inverter that controls the rotational speed of the drive motor to variably control cooling efficiency is installed on one side of the compressor housing.

[0005] Inverters for electric compressors can incorporate various fail-safe features to protect the product. To perform these fail-safe functions, the inverter must internally sense the values ​​of various factors through peripheral circuits. Examples include HV level, DC current, and temperature.

[0006] Meanwhile, the circuit board of an inverter for an electric compressor generally has two separate voltage regions: a high voltage region and a low voltage region.

[0007] The high-voltage region is supplied with voltage from a high-voltage battery (e.g., rated voltage of 150-500 V). The high-voltage region includes the motor control section and power output stage of the electric compressor, and the motor control section includes switching elements.

[0008] The low-voltage region is supplied with board circuitry voltage (e.g., 12 V) from the battery. The low-voltage region contains the electronic control unit that communicates with the upper controller.

[0009] Meanwhile, in the high voltage region, switching noise occurs due to the switching element, and this switching noise causes the ground (GND) to vibrate, which may cause malfunctions in elements that share the ground in the high voltage region, such as the MCU (Microcontroller unit).

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] (Patent Document 1) Korean Patent Publication No. 10-2020-0102785 (Published on September 1, 2020)

[0013]

[0014] The present invention has been devised to solve the above problems, and the purpose of the present invention is to provide an inverter for an electric compressor and an electric compressor employing the same, which can prevent MCU malfunction due to switching noise in a high-voltage region by positioning the MCU in a low-voltage region of a circuit board separated into a high-voltage region and a low-voltage region.

[0015]

[0016] An inverter for an electric compressor according to one embodiment of the present invention is an inverter for an electric compressor including a circuit board separated into a high voltage region and a low voltage region, and includes a switching element for switching-controlling a motor of the electric compressor and an MCU for controlling the switching element, wherein the switching element is arranged in the high voltage region, the MCU is arranged in the low voltage region, and various sensors are provided in the high voltage region, an intermediate element is provided between the various sensors and the MCU, and sensing signals output from the various sensors are transmitted to the MCU through the intermediate element.

[0017] In addition, the intermediate element is characterized in that it is placed between the high voltage region and the low voltage region.

[0018] In addition, the high voltage region is provided with a current sensor, a voltage sensor, a temperature sensor, and a phase current sensing unit, and the current sensor outputs a current sensing signal, the voltage sensor outputs a voltage sensing signal, the temperature sensor outputs a temperature sensing signal, and the phase current sensing unit outputs a phase current sensing signal.

[0019] In addition, a first operational amplifier is provided between the high voltage region and the low voltage region, and the phase current sensing signal output from the phase current sensing unit is configured to be transmitted to the MCU via the first operational amplifier, and the first operational amplifier is characterized in that it is configured with an insulating element having insulating performance.

[0020] In addition, the high voltage region is provided with an ADC including a plurality of channels, an isolator is provided between the high voltage region and the low voltage region, and at least one of a current sensing signal output by the current sensor, a voltage sensing signal output by the voltage sensor, and a temperature sensing signal output by the temperature sensor is configured to be transmitted to the ADC, converted into a digital signal, and then transmitted to the MCU via the isolator, and the isolator is characterized in that it is configured with an insulating element having insulating performance.

[0021] In addition, it further includes a sensing circuit for sensing voltage or current, and is characterized in that the sensing circuit is disposed in the high voltage region.

[0022] In addition, the signal between the current sensor, voltage sensor, and temperature sensor and the isolator is configured to be transmitted in an SPI communication manner.

[0023] In addition, an isolator is provided between the high voltage region and the low voltage region, and the PWM signal output by the MCU is configured to be transmitted to the switching element through the isolator, and the isolator is characterized in that it is composed of an insulating element having insulating performance.

[0024] In addition, the high voltage region is provided with a first gate driver, and the PWM signal output by the MCU is configured to pass through the isolator and the first gate driver to the switching element, and the first gate driver is characterized in that it is configured with an insulating element having insulating performance.

[0025] In addition, a second gate driver is provided between the high voltage region and the low voltage region, and a PWM signal output by the MCU is configured to pass through the second gate driver to the switching element, and the second gate driver is characterized in that it is configured with an insulating element having insulating performance.

[0026] In addition, the device further includes an MCU monitoring circuit for monitoring the status of the MCU, a transceiver for performing communication between the MCU and an upper controller, and an LV monitoring circuit for monitoring the voltage of the low-voltage region, wherein the MCU monitoring circuit, the transceiver, and the LV monitoring circuit are each disposed in the low-voltage region.

[0027] In addition, a power conversion circuit is provided between the high voltage region and the low voltage region, and the power conversion circuit is characterized in that it is composed of an insulating element having insulating performance.

[0028] In addition, the present invention further includes a second operational amplifier provided in the low-voltage region, and the phase current sensing signal output to the low-voltage terminal through the first operational amplifier is configured to be transmitted to the MCU through the second operational amplifier.

[0029] In addition, the MCU monitoring circuit is characterized by monitoring the operating status of the MCU in real time and transmitting a reset signal to the MCU when the MCU does not respond for a predetermined period of time.

[0030] In addition, the detection circuit includes a comparator that compares the detected analog signal with a preset reference value, and the comparator outputs a digital signal when the analog signal exceeds the reference value, and the digital signal is characterized in that it is transmitted to the MCU through the isolator.

[0031] In addition, the MCU is characterized in that it is provided only in the low-voltage region, and a separate MCU is not provided in the high-voltage region.

[0032] In addition, the present invention is characterized by including an inverter for an electric compressor including a circuit board separated into a high-voltage region and a low-voltage region, the inverter including a switching element for switching-controlling a motor of the electric compressor and an MCU for controlling the switching element, wherein the switching element is arranged in the high-voltage region, the MCU is arranged in the low-voltage region, and various sensors are provided in the high-voltage region, an intermediate element is provided between the various sensors and the MCU, and a compressor including a motor controlled by the inverter is characterized by the sensing signals output from the various sensors are transmitted to the MCU through the intermediate element.

[0033]

[0034] According to the present invention, by positioning the MCU in a low-voltage region of a circuit board separated into a high-voltage region and a low-voltage region, it is possible to prevent MCU malfunction due to switching noise in the high-voltage region.

[0035] In addition, the present invention is configured to transmit a sensing signal through an intermediate element between elements located in a high-voltage region and an MCU located in a low-voltage region, and at this time, by configuring the intermediate element as an element having insulation performance, stable signal transmission between the high-voltage region and the low-voltage region can be implemented.

[0036]

[0037] Figure 1 is a simplified diagram of the configuration of an inverter according to the present invention.

[0038] Figure 2 is a configuration diagram of an inverter according to the first embodiment of the present invention.

[0039] Figure 3 is a simplified configuration diagram of Figure 2.

[0040] Figure 4 is a configuration diagram of an inverter according to a second embodiment of the present invention.

[0041] Figure 5 is a simplified configuration diagram of Figure 4.

[0042]

[0043] In order to explain the present invention, its operational advantages, and the purpose achieved by the practice of the present invention, preferred embodiments of the present invention are exemplified and examined with reference thereto below.

[0044] First, the terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention, and the singular expression may include plural expressions unless the context clearly indicates otherwise. In addition, it should be understood that the terms "comprise" or "have" in this application are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0045] In describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

[0046] Conventional inverters for electric compressors for vehicles are generally configured to use high voltage (HV) power and low voltage (LV) power, and are thus separated into high voltage and low voltage areas.

[0047] The inverter is configured to detect various information of the inverter to implement motor control and fail-safety logic, and transmit the information to the MCU (micro controller unit) to perform computational processing and control.

[0048] At this time, the conventional general inverter is configured so that the switching element (IGBT) and MCU are located in the high-voltage region. As described above, switching noise occurs in the switching element, causing ground vibration. This may have a negative effect on the MCU, which is located in the high-voltage region together with the switching element and shares the same ground as the switching element, causing malfunction.

[0049] To solve this problem, the present invention positions the MCU in a low-voltage region, thereby preventing MCU malfunction due to switching noise in a high-voltage region.

[0050] At this time, in order to apply the MCU to the low-voltage region, sensing information from various sensors located in the high-voltage region must be transmitted to the MCU located in the low-voltage region. To this end, the present invention provides an intermediate element between the various sensors in the high-voltage region and the MCU in the low-voltage region, and is configured to transmit sensing information through the intermediate element. At this time, stable signal transmission can be implemented by configuring the intermediate element as an element with insulating performance.

[0051] Hereinafter, the present invention will be examined in detail through specific examples.

[0052] FIG. 1 is a simplified diagram of an inverter according to the present invention, FIG. 2 is a diagram of an inverter according to a first embodiment of the present invention, FIG. 3 is a simplified diagram of FIG. 2, FIG. 4 is a diagram of an inverter according to a second embodiment of the present invention, and FIG. 5 is a simplified diagram of FIG. 4. As illustrated, the inverter (100) of the present invention includes a circuit board separated into a high voltage region (10) and a low voltage region (20), and includes a switching element (11) for switching-controlling a motor (M) of an electric compressor, and an MCU (21) for controlling the switching element (11).

[0053] The circuit board is configured to be separated into a high voltage region (10) and a low voltage region (20) based on an electrically insulated central insulating portion (30). The high voltage region (10) may refer to a first circuit board equipped with an HV input terminal (HI) or elements or circuits equipped on the first circuit board together with the first circuit board, and the low voltage region (20) may refer to a second circuit board equipped with an LV input terminal (LI) or elements or circuits equipped on the second circuit board together with the second circuit board, and the first circuit board and the second circuit board may be configured to be physically separated and insulated from each other.

[0054] The switching element (11) can be composed of various types of switching elements such as MOSFET, IGBT, IGCT, SCR, GTO, TRIAC, SSS, PTR, MCT, etc., and can be composed of power semiconductor elements such as SiC and GAN. The switching element (11) receives a PWM signal from the MCU (21) and performs a function of switching control of the switching element.

[0055] The MCU (21) is a semiconductor processor that receives various types of information, performs calculations based on the information, outputs a PWM signal for controlling the switching element (11), and transmits the signal to the switching element (11).

[0056] At this time, the inverter (100) is configured such that the switching element (11) is placed in the high voltage region (10), i.e., the first circuit board, and the MCU (21) is placed in the low voltage region (20), i.e., the second circuit board. That is, the inverter (100) of the present invention has the MCU (21) in the low voltage region (20), and no separate MCU (21) is provided in the high voltage region (10). By configuring the switching element (11) and the MCU (21) separately in this way, it is possible to block the negative influence of the switching element (11) on the MCU (21).

[0057] First, an inverter according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

[0058] The high voltage region (10) is provided with a current sensor (S1), a voltage sensor (S2), a temperature sensor (S3), and a phase current sensing unit (S4). The phase current sensing unit (S4) can be configured using three shunt resistors and a first operational amplifier (OP Amp). The first operational amplifier of the phase current sensing unit (S4) can correspond to the same configuration as the operational amplifier (OP4) described below.

[0059] In addition, an ADC (Analog-to-Digital Converter) (C) including multiple channels is provided in the high voltage region (10), and an isolator (IS) is provided between the high voltage region (10) and the low voltage region (20), i.e., in the insulation section (30). At this time, the ADC (C) may include 4 channels, and the isolator (IS) is composed of an insulating element having insulating performance, and is insulated from each of the high voltage region (10) and the low voltage region (20).

[0060] And as described above, a switching element (11) is located in the high voltage region (10), and an MCU (21) is located in the low voltage region (20).

[0061] In this structure, the current sensor (S1) outputs an analog current sensing signal, and the current sensing signal output from the current sensor (S1) is transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). In addition, the voltage sensor (S2) outputs an analog voltage sensing signal, and the voltage sensing signal output from the voltage sensor (S2) is also transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). In addition, the temperature sensor (S3) outputs an analog temperature sensing signal, and the voltage sensing signal output from the temperature sensor (S3) is transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). At this time, the phase current sensing unit (S4) outputs an analog phase current sensing signal, and the phase current sensing signal output from the phase current sensing unit (S4) is transmitted to the MCU (21) via the first operational amplifier (34). In addition, a second operational amplifier (28) may be further provided in the low voltage region (20), and the phase current sensing signal output from the phase current sensing unit (S4) may be transmitted to the MCU (21) via the first operational amplifier (34) and the second operational amplifier (28).

[0062] In this way, an intermediate element having insulating performance is provided between various sensors located in a high voltage region (10) and an MCU (21) located in a low voltage region (20), and sensing information is transmitted through the intermediate element, thereby insulating the sensing information and implementing stable signal transmission.

[0063] Here, signals between the current sensor (S1), voltage sensor (S2), and temperature sensor (S3) and the isolator (IS) can be configured to be transmitted using the SPI (Serial Peripheral Interface) communication method.

[0064] The MCU (21) calculates and outputs a PWM signal for controlling the switching element (11) based on information received from various sensors, i.e., various sensing signals, and transmits the PWM signal to the switching element (11). At this time, in order to stably transmit the PWM signal of the MCU (21) located in the low voltage region (20) to the switching element (11) located in the high voltage region (10), the present invention is configured so that the PWM signal output from the MCU (21) passes through an isolator (32), and the isolator (32) is placed between the high voltage region (10) and the low voltage region (20).

[0065] That is, an isolator (32) is provided between a high voltage region (10) and a low voltage region (20), and a PWM signal output by an MCU (21) is transmitted to a switching element (11) via the isolator (32). At this time, the isolator (32) is composed of an insulating element having insulating performance. Accordingly, stable signal transmission can be implemented between the MCU (21) located in the low voltage region (20) and the switching element (11) located in the high voltage region (10).

[0066] Here, the isolator (IS) that mediates signals between the current sensor (S1), the voltage sensor (S2), and the temperature sensor (S3) and the MCU (21), and the isolator (32) that mediates signals between the MCU (21) and the switching element (11) correspond to different configurations, and the signals between the MCU (21) and the isolator (32) can also be configured to be transmitted in the SPI communication method.

[0067] Furthermore, a first gate driver (12) is provided in the high voltage region (10), and a PWM signal output by the MCU (21) is transmitted to an isolator (32), transmitted from the isolator (32) to the first gate driver (12), and transmitted from the first gate driver (12) to the switching element (11). At this time, the first gate driver (12) is configured as an insulating element having insulating performance, and may include a single channel or dual channels as needed. Through this, more stable signal transmission between the high voltage region (10) and the low voltage region (20) can be implemented.

[0068] A first operational amplifier (34) is provided between the high voltage region (10) and the low voltage region (20), i.e., in the insulating section (30). At this time, the first operational amplifier (34) is composed of an insulating element having insulating performance, and is insulated from each of the high voltage region (10) and the low voltage region (20).

[0069] And, as described above, a switching element (11) is located in the high voltage region (10), and an MCU (21) is located in the low voltage region (20).

[0070] In this structure, the phase current sensing unit (S4) outputs a phase current sensing signal, and the phase current sensing signal output from the phase current sensing unit (S4) is transmitted to the MCU (21) through the first operational amplifier (34).

[0071] In this way, an intermediate element having insulating performance is provided between various sensors located in a high voltage region (10) and an MCU (21) located in a low voltage region, and sensing information is transmitted through the intermediate element, thereby insulating the sensing information and implementing stable signal transmission.

[0072] Here, the current sensing signal output by the current sensor (S1), the voltage sensing signal output by the voltage sensor (S2), the temperature sensing signal output by the temperature sensor (S3), and the phase current sensing signal output by the phase current sensing unit (S4) are each analog signals, and the current sensing signal, the voltage sensing signal, and the temperature sensing signal can be converted into a digital signal by an ADC (C) located in the high voltage region (10), and the phase current sensing signal can be converted into a digital signal by the internal ADC function of the MCU (21) after being transmitted to the MCU (21).

[0073] In addition, the inverter (100) of the present example further includes a sensing circuit (SC) that senses voltage or current, and the sensing circuit (SC) is placed in a high voltage region (10).

[0074] The detection circuit (SC) detects the input voltage or current and outputs a detection signal, and the detection signal output from the detection circuit (SC) is a digital signal and is transmitted to the MCU (21). At this time, the detection circuit (SC) can detect the input voltage or current by including a comparator and compare the generated analog signal with a preset reference value. The comparator can output a digital signal, which is a detection signal, when the analog signal exceeds the reference value. In addition, the digital signal can be transmitted to the MCU (21) through an isolator (IS).

[0075] The inverter (100) of this example further includes an MCU monitoring circuit (22) that monitors the status of the MCU (21), a transceiver (23) that performs communication between the MCU (21) and an upper controller, and an LV monitoring circuit (24) that monitors the voltage of a low voltage region (20), and the MCU monitoring circuit (24), the transceiver (23), and the LV monitoring circuit (24) are each placed in the low voltage region (20).

[0076] The MCU monitoring circuit (22) is located in the low voltage region (20) close to the MCU (21) to monitor the current status of the MCU (21), and can output a reset signal to the MCU (21) when there is no response from the MCU (21) for a certain period of time.

[0077] The transceiver (23) can be placed between the MCU (21) and the upper controller, and can receive the Tx signal of the MCU (21) and transmit it to the upper controller, or receive the Rx signal of the upper controller and transmit it to the MCU (21). The signal output from the transceiver (23) is a digital signal, and the transceiver (23) can be configured as a LIN (Local Interconnect Network) transceiver (23).

[0078] The LV monitoring circuit (24) is connected to the LV input filter (25) of the LV input terminal (LI) to monitor the voltage of the low voltage region (20) and output a monitoring signal. The monitoring signal output from the LV monitoring circuit (24) is a digital signal and the corresponding signal is transmitted to the MCU (21).

[0079] Referring again to FIG. 2, the inverter (100) of the present example further includes a power conversion circuit (31), and the power conversion circuit (31) is positioned between the high voltage region (10) and the low voltage region (20).

[0080] The power conversion circuit (31) is configured with an insulating element having insulating performance and is configured to be insulated from the high voltage region (10) and the low voltage region (20). The power conversion circuit (31) receives a low voltage (e.g., 12 V) from the LV input terminal (LI), converts it into a low voltage (e.g., 5 V) and a high voltage (e.g., 18 V and 6.5 V) and outputs them. At this time, the low voltage (12 V) output by the power conversion circuit (31) can be used as a power source for elements (IC) in the low voltage region (20), and the high voltage (18 V, 6.5 V) output by the power conversion circuit (31) can be used as a power source for elements (IC) in the high voltage region (10).

[0081] Meanwhile, the inverter (100) of the present example may further include an HV input terminal (HI) located in a high voltage region (10), an LV input terminal (LI) located in a low voltage region (20), and a low voltage input terminal EMC filter (27).

[0082] Next, an inverter according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 5.

[0083] The high voltage region (10) is equipped with a current sensor (S1), a voltage sensor (S2), a temperature sensor (S3), and a phase current sensing unit (S4). The phase current sensing unit (S4) can be configured using three shunt resistors and an operational amplifier (OP Amp). The operational amplifier of the phase current sensing unit (S4) can correspond to the same configuration as the operational amplifier (OP4) described below.

[0084] In addition, an ADC (Analog-to-Digital Converter) (C) including multiple channels is provided in the high voltage region (10), and an isolator (IS) is provided between the high voltage region (10) and the low voltage region (20), i.e., in the insulation section (30). At this time, the ADC may include 4 channels, and the isolator (IS) is composed of an insulating element having insulation performance, and is insulated from each of the high voltage region (10) and the low voltage region (20).

[0085] And as described above, a switching element (11) is located in the high voltage region (10), and an MCU (21) is located in the low voltage region (20).

[0086] In this structure, the current sensor (S1) outputs an analog current sensing signal, and the current sensing signal output from the current sensor (S1) is transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). In addition, the voltage sensor (S2) outputs an analog voltage sensing signal, and the voltage sensing signal output from the voltage sensor (S2) is also transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). In addition, the temperature sensor (S3) outputs an analog temperature sensing signal, and the voltage sensing signal output from the temperature sensor (S3) is transmitted to the ADC (C) and converted into a digital signal, and then transmitted to the MCU (21) through the isolator (IS). At this time, the phase current sensing unit (S4) outputs an analog phase current sensing signal, and the phase current sensing signal output from the phase current sensing unit (S4) is transmitted to the MCU (21) through the first operational amplifier (34).

[0087] In this way, an intermediate element having insulating performance is provided between various sensors located in a high voltage region (10) and an MCU (21) located in a low voltage region (20), and sensing information is transmitted through the intermediate element, thereby insulating the sensing information and implementing stable signal transmission.

[0088] Here, signals between the current sensor (S1), voltage sensor (S2), and temperature sensor (S3) and the isolator (IS) can be configured to be transmitted using the SPI (Serial Peripheral Interface) communication method.

[0089] The MCU (21) calculates and outputs a PWM signal for controlling the switching element (11) based on information received from various sensors, i.e., various sensing signals, and transmits the PWM signal to the switching element (11). At this time, in order to stably transmit the PWM signal of the MCU (21) located in the low voltage region (20) to the switching element (11) located in the high voltage region (10), the present invention is configured so that the PWM signal output from the MCU (21) passes through the second gate driver (33), and the second gate driver (33) is placed between the high voltage region (10) and the low voltage region (20).

[0090] That is, in another embodiment of the present invention, a second gate driver (33) is provided between a high voltage region (10) and a low voltage region (20), and a PWM signal output by an MCU (21) is transmitted to a switching element (11) via the second gate driver (33). At this time, the second gate driver (33) is configured as an insulating element having insulating performance. Accordingly, stable signal transmission can be implemented between the MCU (21) located in the low voltage region (20) and the switching element (11) located in the high voltage region (10).

[0091] In addition, a first operational amplifier (34) is provided between the high voltage region (10) and the low voltage region (20), i.e., in the insulating section (30). At this time, the first operational amplifier (34) is composed of an insulating element having insulating performance, and is insulated from each of the high voltage region (10) and the low voltage region (20).

[0092] And, as described above, a switching element (11) is located in the high voltage region (10), and an MCU (21) is located in the low voltage region (20).

[0093] In this structure, the phase current sensing unit (S4) outputs a phase current sensing signal, and the phase current sensing signal output from the phase current sensing unit (S4) is transmitted to the MCU (21) through the first operational amplifier (34).

[0094] In this way, an intermediate element having insulating performance is provided between various sensors located in a high voltage region (10) and an MCU (21) located in a low voltage region, and sensing information is transmitted through the intermediate element, thereby insulating the sensing information and implementing stable signal transmission.

[0095] Here, the current sensing signal output by the current sensor (S1), the voltage sensing signal output by the voltage sensor (S2), the temperature sensing signal output by the temperature sensor (S3), and the phase current sensing signal output by the phase current sensing unit (S4) are each analog signals, and the current sensing signal, the voltage sensing signal, and the temperature sensing signal can be converted into a digital signal by an ADC (C) located in the high voltage region (10), and the phase current sensing signal can be converted into a digital signal by the internal ADC function of the MCU (21) after being transmitted to the MCU (21).

[0096] In summary, the first and second embodiments adopt an isolator (IS, 32) as an intermediate element, and are configured to first convert analog sensing signals output from the current sensor (S1), voltage sensor (S2), and temperature sensor (S3) into digital signals and transmit them to the MCU (21) via the isolator (IS, 32), which is an intermediate element, while the analog sensing signal output from the phase current sensing unit (S4) is configured to transmit them to the MCU (21) via the first operational amplifier (34), which is an intermediate element. This ensures the stability of the element and the system, and further has the effect of improving the precision of the motor. On the other hand, the first embodiment places the first gate driver (12) in the high voltage region (10), whereas the second embodiment places the second gate driver (33) between the high voltage region (10) and the low voltage region (20), i.e., in the insulating portion (30), which is different.

[0097] In addition, the MCU monitoring circuit (22), transceiver (23), LV monitoring circuit (24), and power conversion circuit (31) of the second embodiment can be configured in the same manner as in the first embodiment.

[0098] Specifically, the inverter (100) of the present example further includes an MCU monitoring circuit (24) that monitors the status of the MCU (21), a transceiver (23) that performs communication between the MCU (21) and an upper controller, and an LV monitoring circuit (24) that monitors the voltage of a low voltage region (20), and the MCU monitoring circuit (22), the transceiver (23), and the LV monitoring circuit (24) are each placed in the low voltage region (20).

[0099] The MCU monitoring circuit (22) is located in the low voltage region (20) close to the MCU (21) to monitor the current status of the MCU (21), and can output a reset signal to the MCU (21) when there is no response from the MCU (21) for a certain period of time.

[0100] The transceiver (23) can be placed between the MCU (21) and the upper controller, and can receive the Tx signal of the MCU (21) and transmit it to the upper controller, or receive the Rx signal of the upper controller and transmit it to the MCU (21). The signal output from the transceiver (23) is a digital signal, and the transceiver (23) can be configured as a LIN (Local Interconnect Network) transceiver (23).

[0101] The LV monitoring circuit (24) is connected to the LV input filter (25) of the LV input terminal (LI) to monitor the voltage of the low voltage region (20) and output a monitoring signal. The monitoring signal output from the LV monitoring circuit (24) is a digital signal and the corresponding signal is transmitted to the MCU (21).

[0102] Referring again to FIG. 4, the inverter (100) of the present example further includes a power conversion circuit (31), and the power conversion circuit (31) is positioned between the high voltage region (10) and the low voltage region (20).

[0103] The power conversion circuit (31) is configured with an insulating element having insulating performance and is configured to be insulated from the high voltage region (10) and the low voltage region (20). The power conversion circuit (31) receives a low voltage (e.g., 12 V) from the LV input terminal (LI), converts it into a low voltage (e.g., 5 V) and a high voltage (e.g., 18 V and 6.5 V) and outputs them. At this time, the low voltage (12 V) output by the power conversion circuit (31) can be used as a power source for elements (IC) in the low voltage region (20), and the high voltage (18 V, 6.5 V) output by the power conversion circuit (31) can be used as a power source for elements (IC) in the high voltage region (10).

[0104] Meanwhile, referring again to FIG. 4, the inverter (100) of the present example may further include an HV input terminal (HI) located in a high voltage region (10), an LV input terminal (LI) located in a low voltage region (20), and a low voltage input terminal EMC filter (27).

[0105] As described above, the present invention can prevent MCU malfunction due to switching noise generated from a switching element located in a high-voltage region by positioning the MCU in a low-voltage region of a circuit board separated into a high-voltage region and a low-voltage region, and can implement stable signal transmission between the high-voltage region and the low-voltage region by configuring a signal to be transmitted between the elements located in the high-voltage region and the MCU located in the low-voltage region through an insulator element.

[0106] Meanwhile, although not separately illustrated, the present invention may be configured as an electric compressor comprising a compressor including the above-described inverter (100) and a motor (M) controlled by the inverter (100). The compressor includes a motor section including the motor (M) and a compression section driven by the motor (M), and the inverter (100) may be mounted on one side of the housing of the compressor, and the electric compressor of the present invention may correspond to an electric compressor for a vehicle.

[0107]

[0108] While preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above. That is, those skilled in the art to which the present invention pertains may make numerous changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications should be considered equivalents and fall within the scope of the present invention.

[0109] [Explanation of symbols]

[0110] 100: Inverter

[0111] 10: High voltage area

[0112] 11: Switching element

[0113] 12: First gate driver

[0114] 13: HV input filter / Surge protector

[0115] 14: HV DC Link

[0116] S1: Current sensor (HV DC current sensor)

[0117] S2: Voltage sensor (HV sensor)

[0118] S3: Temperature sensor

[0119] S4: Phase current sensing unit

[0120] SC: Short circuit monitoring

[0121] C: ADC

[0122] 20: Low voltage area

[0123] 21: MCU

[0124] 22: MCU monitoring circuit

[0125] 23: Transceiver

[0126] 24: LV monitoring circuit

[0127] 25: LV input filter

[0128] 26: Interlock monitoring

[0129] 27: Low-voltage input EMC filter (LIN EMC Filter)

[0130] 28: Second operational amplifier (OPAMP)

[0131] 30: Insulation

[0132] 31: Power conversion circuit

[0133] IS, 32: Isolator

[0134] 33: Second gate driver

[0135] 34: Isolated OPAMP

Claims

1. An inverter for an electric compressor including a circuit board separated into a high voltage region and a low voltage region, It includes a switching element that switches and controls the motor of the electric compressor, and an MCU that controls the switching element. The above switching element is placed in the high voltage region, The above MCU is placed in the low voltage region, Various sensors are installed in the above high voltage area. An intermediate element is provided between the various sensors and the MCU. Through the above intermediate elements, the sensing signals output from the various sensors are transmitted to the MCU. Inverter.

2. In paragraph 1, The above intermediate element is placed between the high voltage region and the low voltage region, Inverter.

3. In paragraph 2, The above high voltage region is equipped with a current sensor, a voltage sensor, a temperature sensor, and a phase current sensing unit. The above current sensor outputs a current sensing signal, The above voltage sensor outputs a voltage sensing signal, The above temperature sensor outputs a temperature sensing signal, The above-mentioned phase current sensing unit outputs a phase current sensing signal, Inverter.

4. In paragraph 3, A first operational amplifier is provided between the high voltage region and the low voltage region, The phase current sensing signal output by the above phase current sensing unit is configured to be transmitted to the MCU through the first operational amplifier, The above first operational amplifier is composed of an insulating element having insulating performance. Inverter.

5. In paragraph 3, The above high voltage region is equipped with an ADC including multiple channels, An isolator is provided between the high voltage region and the low voltage region. At least one of the current sensing signal output by the current sensor, the voltage sensing signal output by the voltage sensor, and the temperature sensing signal output by the temperature sensor is configured to be transmitted to the ADC, converted into a digital signal, and then transmitted to the MCU through the isolator. The above isolator is composed of an insulating element having insulating performance. Inverter.

6. In paragraph 5, Further comprising a sensing circuit for sensing voltage or current, The above detection circuit is placed in the high voltage region, Inverter.

7. In paragraph 5, The signals between the current sensor, voltage sensor, and temperature sensor and the isolator are configured to be transmitted using the SPI communication method. Inverter.

8. In paragraph 2, An isolator is provided between the high voltage region and the low voltage region, The PWM signal output by the above MCU is configured to be transmitted to the switching element through the above isolator, The above isolator is composed of an insulating element having insulating performance. Inverter.

9. In paragraph 8, The above high voltage region is provided with a first gate driver, The PWM signal output by the above MCU is configured to be transmitted to the switching element through the first gate driver via the above isolator, The above first gate driver is composed of an insulating element having insulating performance. Inverter.

10. In paragraph 2, A second gate driver is provided between the high voltage region and the low voltage region, The PWM signal output by the above MCU is configured to be transmitted to the switching element through the second gate driver, The above second gate driver is composed of an insulating element having insulating performance. Inverter.

11. In paragraph 2, An MCU monitoring circuit that monitors the status of the above MCU, A transceiver that performs communication between the above MCU and the upper controller, Further comprising an LV monitoring circuit for monitoring the voltage in the above low voltage region, The above MCU monitoring circuit, the transceiver, and the LV monitoring circuit are each placed in the low voltage region. Inverter.

12. In paragraph 2, A power conversion circuit is provided between the high voltage region and the low voltage region, The above power conversion circuit is composed of an insulating element having insulating performance. Inverter.

13. In paragraph 4, Further comprising a second operational amplifier provided in the above low voltage region, The phase current sensing signal output to the low voltage terminal through the first operational amplifier is configured to be transmitted to the MCU through the second operational amplifier. Inverter.

14. In paragraph 11, The above MCU monitoring circuit monitors the operating status of the MCU in real time, If there is no response from the MCU for a predetermined period of time, a reset signal is transmitted to the MCU. Inverter.

15. In paragraph 6, The above detection circuit includes a comparator that compares the detected analog signal with a preset reference value, The above comparator outputs a digital signal when the analog signal exceeds the reference value, and the digital signal is transmitted to the MCU through the isolator. Inverter.

16. In paragraph 1, The above MCU is equipped only in the low voltage region, The above high voltage area is not equipped with a separate MCU. Inverter.

17. The inverter of paragraph 1; and A compressor comprising a motor controlled by the inverter; Electric compressor.

Images