JP2005261104A - Inverter arrangement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter arrangement capable of constituting a transmitter/receiver at a low cost using integration technology and pattern wiring technology and by using the transmitter/receiver as an insulating means for electrically insulating a control circuit and an inverter circuit, and also capable of sharing a part of the circuit, for less cost, by employing a single transmitter for a plurality of receivers or employing a single receiver for a plurality of transmitters. <P>SOLUTION: The on/off signal for driving an IGBT from a micro computer 1 is transmitted to six receivers 4-9 from a transmitter 2. The on/off control signal received by the receivers 4-9 on/off controls six IGBTs/Tr(UP), Tr(VP), Tr(WP), Tr(UN), Tr(VN), and Tr(WN) in an inverter circuit 10. The reception frequency of the signal transmitted by the six receivers 4-9 are so set that the frequency of odd-number multiple is different from the reception frequency of other receivers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an insulating device that insulates between a high voltage circuit and a low voltage circuit, and more particularly to an insulating device suitable for use as an electronic circuit for an automobile.

  In an inverter device for an automobile such as an electric vehicle (EV) or a hybrid vehicle (HEV), a control circuit that drives the inverter circuit on and off and an inverter circuit that is driven by the control circuit and converts a DC voltage into an AC voltage are used. It has been. Here, the drive voltage of the control circuit is, for example, a low voltage of + 5V, while a high voltage of, for example, about + 300V is used for the inverter circuit. Therefore, an insulating means for electrically insulating is used between the control circuit and the inverter circuit.

  As an insulating means, for example, as described in JP-A-8-280168, a device that uses a photocoupler between a power element and a microcomputer signal to insulate by spatial transmission of an optical signal is known.

JP-A-8-280168

  Here, in an inverter device for an automobile, when obtaining a three-phase AC voltage, it is necessary to use at least 12 photocouplers. That is, looking at one phase, since switching circuits are provided in the upper arm and the lower arm, in the case of three phases, six switching circuits are required and six photocouplers are also required. Further, since it is necessary to provide a temperature abnormality detection circuit for each upper and lower arm of each phase and to send the detection signal to the control circuit, six photocouplers are further required. As a result, the ratio of the photocoupler in the total cost of the inverter device is ¼ to ３, and the inverter device is expensive.

  An object of the present invention is to provide an inexpensive insulating device.

(1) In order to achieve the above object, the present invention comprises an insulating means for insulating an input / output signal between a first circuit connected to a high voltage power source and a second circuit connected to a low voltage power source. In the insulating device, the insulating means is connected to one or a plurality of transmitters that transmit an output signal of the first circuit or the second circuit, and the second circuit or the first circuit, It comprises a plurality of or one receiver for receiving the signal transmitted from the transmitter.
With this configuration, the cost of the insulating device can be reduced.

  (2) In the above (1), preferably, the transmission frequency of the signal transmitted from the plurality of transmitters is different from the transmission frequency of other transmitters in the odd multiple of the transmission frequency of the plurality of receivers. The reception frequency of the signal received by is such that the odd frequency is different from the reception frequency of other receivers.

  (3) In the above (2), preferably, the first circuit includes a plurality of power semiconductor switching elements for switching a high voltage supplied from a high voltage power source, and the second circuit includes the power semiconductor. A microcomputer for controlling on / off of the switching element is provided, and an on / off control signal of the power semiconductor switching element output from the microcomputer is transmitted from one transmitter, and corresponds to the plurality of power semiconductor switching elements. The on / off control signal is received by each of a plurality of receivers provided.

  (4) In the above (2), preferably, the first circuit includes a plurality of power semiconductor switching elements that switch a high voltage supplied from a high-voltage power source, and a plurality of these power semiconductor switching elements. A plurality of overcurrent detection circuits for detecting that the current flowing through the overcurrent detection circuit is an overcurrent, and the second circuit includes a microcomputer for receiving overcurrent information of the power semiconductor switching element, and the overcurrent detection The overcurrent detection signal output from the circuit is transmitted from a plurality of transmitters provided corresponding to each of the plurality of overcurrent detection circuits, and is received by one receiver provided in the first circuit. The overcurrent detection is received.

  (5) In the above (1), preferably, the transmitter is mounted on one surface of the substrate, and the receiver is mounted on the other surface of the substrate.

  According to the present invention, the cost of the inverter device can be reduced.

Hereinafter, the configuration of an inverter device according to an embodiment of the present invention will be described with reference to FIGS.
Initially, the whole structure of the inverter apparatus by this embodiment is demonstrated using FIG.
FIG. 1 is a block diagram showing the overall configuration of an inverter device according to an embodiment of the present invention.

  The three-phase brushless motor 11 is controlled by the microcomputer 1. The microcomputer 1 outputs six-phase PWM pulse signals UP, VP, WP, UN, VN, and WN, which are pulse commands for the three-phase brushless motor 11, to the transmitter 2. The PWM pulse signals UP, VP, WP, UN, VN, and WN serve as drive commands for the inverter circuit 10.

  Here, when the power supply HV for supplying power to the motor 11 is a high voltage of several hundred volts, for example, the IGBT / Tr (UP) and IGBT / Tr (WP) which are power semiconductor switching elements in the inverter circuit 10 are turned ON. When the power is supplied to the motor 11, the emitter voltage of each element has a potential difference of several hundred volts, so the 12V power source LV that operates the microcomputer 1 and the power source HV that supplies power to the motor 11 are insulated. There is a need.

  Conventionally, for this insulation, an IGBT driving pulse signal has been insulated using an optical semiconductor element (photocoupler). However, the optical semiconductor has a problem in that it is difficult to suppress the deterioration of the optical coupling portion due to the temperature cycle, and the life is shortened in a severe vehicle-mounted environment. In addition, since the number of photocouplers is large, there is a problem that the cost increases.

  Therefore, in the present embodiment, the pulse commands UP, VP, WP, UN, VN, and WN of the microcomputer 1 are generated from the high-frequency transmitter 2 that generates different frequencies and modulation signals for each pulse command, and the radio waves as pulse signals. The receivers 4, 5, 6, 7, 8, 9 are demodulated, and the transmitter 2 and the receivers 4,... The transmitter 2 and the receivers 4,..., 9 are housed inside the shield case 3 and shielded from the outside.

  The PWM pulse signals UP, VP, WP, UN, VN, WN transmitted from the high frequency transmitter 2 are demodulated by the corresponding receivers 4, 5, 6, 7, 8, 9 respectively, and driver circuits Dup, Dvp , Dwp, Dun, Dvn, Dwn.

  The inverter circuit 10 includes driver circuits Dup, Dvp, Dwp, Dun, Dvn, Dwn, and IGBT / Tr (UP), Tr (VP), Tr (WP), Tr (UN), Tr (VN), Tr (WN). ), Diodes dup, dvp, dwp, dun, dvn, dwn, and overcurrent detection circuits Iup, Ivp, Iwp, Iun, Ivn, Iwn.

  For example, when the UP signal is set to Hi, the output of the receiver 4 becomes Hi, the driver circuit Dup outputs a Hi level output, and the IGBT Tr (UP) provided in the upper arm of the U phase in the inverter circuit 10 When the WN signal is set to Hi at the same time, the IGBT Tr (WN) provided in the lower arm of the W phase in the inverter circuit 10 is turned ON, and the U phase and W phase coils of the motor 11 are energized. To do. When the UP signal is set to Low, the IGBT · Tr (UP) in the inverter circuit 10 is turned OFF, and when the WN signal is set to Low, the IGBT · Tr (WN) in the inverter circuit 10 is turned OFF. Similarly, IGBT · Tr (VP), Tr (WP), Tr (UN), and Tr (VN) are also turned ON / OFF by the VP signal, WP signal, UN signal, and VN signal.

  The overcurrent detection circuit Iup is connected between the emitter and collector of the IGBT · Tr (UP), and outputs a Hi signal when a current larger than a predetermined current value flows to detect the overcurrent. Similarly, the overcurrent detection circuits Ivp, Iwp, Iun, Ivn, and Iwn are respectively overcurrents of the corresponding IGBT / Tr (VP), Tr (WP), Tr (UN), Tr (VN), and Tr (WN). Is detected. When the overcurrent detection circuit Iup outputs a Hi signal, the transmitter 12 outputs a signal modulated at a predetermined frequency from the antenna, and the signal is demodulated and detected by the receiver 18. Similarly, the transmitters 13, 14, 15, 16, and 17 modulate and output the outputs of the overcurrent detection circuits Ivp, Iwp, Iun, Ivn, and Iwn, and the signals are demodulated and detected by the receiver 18. The The modulation frequencies in the transmitters 12, 13, 14, 15, 16, and 17 are different from each other. The transmitters 12, 13, 14, 15, 16, 17 and the receiver 18 are housed inside the shield case 19 and are shielded from the outside.

Next, the configuration of the transmitter 2 used in the inverter device according to the present embodiment will be described with reference to FIG.
FIG. 2 is a block diagram showing a configuration of a transmitter used in the inverter device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  The transmitter 2 includes a modulation circuit 20 that generates a modulation signal according to each pulse UP, VP, WP, UN, VN, and WN output from the microcomputer 1, and a high-frequency amplifier 21 that amplifies the signal level. The The modulation circuit 20 includes sine wave oscillators 23, 24, 25, 26, 27, 28 having different oscillation frequencies, an addition circuit 30, and an amplitude modulation circuit 29.

  The pulse commands UP, VP, WP, UN, VN, WN of the microcomputer 1 are applied to the sine wave oscillators 23,..., 28, respectively, and the oscillators 23,. Is configured to oscillate. The sine wave oscillators 23,..., 28 have different transmission frequencies. For example, the transmission frequency of the oscillator 23 is 11 MHz, the transmission frequency of the oscillator 24 is 19 MHz, and the transmission frequency of the oscillator 25 is 29 MHz. The transmission frequency of 26 is 41 MHz, the transmission frequency of the oscillator 27 is 53 MHz, and the transmission frequency of the oscillator 28 is 61 MHz. These frequencies are selected so as to prevent interference due to higher harmonics when demodulating by a demodulator, as will be described later.

  The output signals of the oscillators 23,..., 28 are synthesized by the adder circuit 30 and the amplitude modulation circuit 29 amplitude-modulates the 2.4 GHz carrier signal. The wavelength λ of this carrier frequency is about 30 cm at 1 GHz, and becomes shorter as the frequency becomes higher. In the case of 2.4 GHz, the wavelength λ is about 12.5 cm. In addition, when an antenna having a wavelength of 1/2 is used, radio waves can be efficiently radiated into the space. Therefore, in order to reduce the size of the inverter, it is desirable to set the carrier frequency to a high frequency of about 1 GHz or more.

  For example, when the UP and WN pulses are Hi, the 11 MHz oscillator 23 and the 41 MHz oscillator 26 operate, and the high frequency amplifier 21 amplifies the 2.4 GHz high frequency signal that is amplitude-modulated by the combined signal and outputs it.

Next, the configuration of the receivers 4,..., 9 used in the inverter device according to the present embodiment will be described with reference to FIGS.
FIG. 3 is a block diagram showing a configuration of a receiver used in the inverter device according to the embodiment of the present invention. FIG. 4 is a circuit diagram showing a specific configuration of a receiver used in the inverter device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  As shown in FIG. 3, the receivers 4,..., 9 have antennas 45, 55, 65, 75, 85, 95, and tuning circuits 41, 51, tuned to 2.4 GHz amplitude-modulated signals, respectively. 61, 71, 81, 91, tuning circuits 42, 52, 62, 72, 82, 92 tuned to the respective frequencies of the receivers 4,. Rectification circuits 43, 53, 63, 73, 83, and 93 for rectifying and shaping the waveform are provided, and the received signal is converted into a pulse signal.

Further, as specifically shown in FIG. 4, the tuning circuits 41 and 42 constitute a 2.4 GHz tuning circuit by the coil 411 and the capacitor 412, and an 11 MHz tuning circuit by the coil 421 and the capacitor 422. The tuning circuit 41 includes a diode 413 for half-wave rectification. The tuning circuit can change the pass frequency by adjusting the capacitance of each coil and capacitor as shown in equation (1).

Pass frequency (Hz) = 1 / (2π√ (LC)) (1)

Here, L is the inductance (H) of the coils 411 and 421, and C is the capacitance (F) of the capacitors 412 and 422.

  The tuning circuits 42, 52, 62, 72, 82, and 92 have different values of L and C, respectively, and pass frequencies of 11 MHz, 19 MHz, 29 MHz, 41 MHz, 53 MHz, and 61 MHz. This frequency is selected so as not to affect other channels even when waveform distortion occurs in the sine wave. When distortion occurs in the sine wave signal, higher harmonics of the fundamental frequency are generated. As an example, when 11 MHz becomes a square wave, odd-numbered higher harmonics of 33 MHz, 55 MHz, 77 MHz,. For this reason, as the setting of each frequency, a frequency in which an odd integer multiple of each frequency does not match (is different) is selected. As a result, even when distortion occurs in the sine wave signal, the influence on other channels can be prevented. However, since there are various situations such as waveform distortion and noise environment, it is not limited to such frequency setting.

  Next, the detection signal that has passed through the tuning circuit 42 is demodulated into a pulse signal by the rectifier circuit 43. First, the sine wave signal that has passed through the tuning circuit 42 is half-wave rectified by a diode 431 and then smoothed by an integrating circuit using a capacitor 432. The smoothed signal has a high voltage level if there is a detection signal (sine wave signal), and small if there is no detection signal. By comparing this voltage level with a reference voltage 434 using a comparator circuit 435 and converting it to a pulse signal, it can be demodulated into an IGBT drive pulse. The discharge resistor 433 is a resistor for discharging the capacitor 432 when the detection signal of the tuning circuit 42 is lost.

  In the above example, amplitude modulation (AM) is shown, but other modulation methods such as frequency modulation (FM) and pulse code modulation (PCM) may be used. Since FM modulation can be cut by a limiter even if noise is superimposed in the amplitude direction, deterioration of modulation information can be reduced. In addition, PCM modulation can reduce information deterioration due to noise by adding a code for error detection and correction. The reliability of pulse transmission can be improved.

  The configurations of the transmitters 12,..., 17 and the receiver 18 are the same as the configurations of the transmitter 2 and the receivers 4,. However, the transmitters 12,..., 17 are not provided with an adder 30 as compared with the configuration shown in FIG. 2, and each of them has a modulation circuit composed of one oscillator and one amplitude modulator. The configuration further includes a high frequency amplifier. For the receiver 18, these receivers 4,..., 9 are combined with the configuration shown in FIG. 3, and one 2.4 GHz tuning circuit and six low frequency tuning circuits having different tuning frequencies. And six demodulation circuits.

Next, the mounting arrangement of the transceiver used in the inverter device according to the present embodiment will be described with reference to FIG.
FIG. 5 is a plan layout diagram showing the mounting layout of the transceiver used in the inverter device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  On the printed circuit board 31 made of glass epoxy or the like, the transmitter 2 and antennas 22 and 22 ′ that efficiently convert the carrier frequency 2.4 GHz of the transmitter 2 into radio waves are arranged. Similarly, on the printed circuit board 31, receiving antennas 45, 55, 65, 75, 85, and 95 and receivers 4,.

  The length of the transmission antennas 22 and 22 ′ is about 6.25 cm which is ½ of the wavelength λ (about 12.5 cm) of the carrier frequency 2.4 GHz of the transmitter 2, and the reception antennas 45, 55, 65, The lengths of 75, 85, and 95 are about 3.1 cm, which is a quarter of the wavelength λ (about 12.5 cm) of the carrier frequency of 2.4 GHz of the transmitter 2, and efficient transmission and reception is possible. . Between the transmitting antennas 22 and 22 ′ and the receiving antennas 45, 55, 65, 75, 85, and 95 and between the transmitter 2 and the receivers 4,. When the potential difference ΔV is 300 V, the creeping distance of about 9.5 mm or more is provided, so that the transmitter 2 and the receivers 4,. The lengths of the receiving antennas 45, 55, 65, 75, 85, and 95 are not particularly problematic even if a small antenna of about λ / 10 is used.

Next, another mounting arrangement of the transceiver used in the inverter device according to the present embodiment will be described with reference to FIG.
FIG. 6 is a perspective view showing another mounting arrangement of the transceiver used in the inverter device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  The transmitter 2 and the transmission antenna 22 are mounted on the surface of the printed circuit board 31. A receiver 4 and an antenna 45 are mounted on the back surface of the printed circuit board 31. Although not shown, the receiving antennas 55, 65, 75, 85, and 95 and the receivers 5,..., And 9 are similarly mounted on the back surface of the printed board 31. Each transmitter 2 and receiver 4,..., 9 are accommodated in the shield case 3. The shield case 3 is made of a material such as iron that is difficult to transmit radio waves and magnetism.

  In this way, by separating and mounting the transmitter and the receiver on the front and back surfaces of the printed circuit board 31, electrical insulation can be further improved. Moreover, by covering the printed circuit board 31 with the shield case 3, it is possible to prevent the influence of external radio waves and the emission of radio waves to the outside.

  In the above description, in order to control a motor for an automobile, an inverter device that converts direct current into alternating current is taken as an example. For example, the voltage of a high voltage battery in which a plurality of battery cells are connected in series is detected, It can also be used for a battery control device for controlling a battery cell. In addition, the above example is premised on in-vehicle use, but since long-term reliability is improved, a high-quality inverter with few failures can be obtained even when applied to general industrial uses or home appliances such as air conditioners, refrigerators, and washing machines. Can be provided.

  As described above, since the transmitter / receiver is used as an insulating means for electrically insulating the control circuit and the inverter circuit, the transmitter / receiver can be configured at low cost by integration technology and pattern wiring technology. Cost can be reduced with respect to the insulating means by the photocoupler. Furthermore, when there are a plurality of receivers, one transmitter is used. When there are a plurality of transmitters, a single receiver can be used to share a part of the circuit. Furthermore, the cost can be reduced.

In addition, electronic circuits generally used in automobiles must satisfy conditions such as a wide operating temperature range from −40 ° C. to 125 ° C. and vibration over a long period of 10 years or more. However, conventionally used optical semiconductors such as photocouplers are structurally difficult to suppress degradation of the optical coupling portion due to temperature cycles, and there is a risk of shortening the life in harsh in-vehicle environments. On the other hand, by using a transmitter / receiver, an insulated signal transmission circuit to a power element can satisfy on-vehicle application conditions such as a wide operating temperature range from −40 ° C. to 125 ° C. and long-term vibration of 10 years or more. Insulation signal transmission to the power element can be made long and reliable.

1 is a block diagram illustrating an overall configuration of an inverter device according to an embodiment of the present invention. It is a block diagram which shows the structure of the transmitter used for the inverter apparatus by one Embodiment of this invention. It is a block diagram which shows the structure of the receiver used for the inverter apparatus by one Embodiment of this invention. It is a circuit diagram which shows the specific structure of the receiver used for the inverter apparatus by one Embodiment of this invention. It is a plane arrangement | positioning figure which shows mounting arrangement of the transmitter / receiver used for the inverter apparatus by one Embodiment of this invention. It is a perspective layout figure which shows the other mounting arrangement of the transmitter / receiver used for the inverter apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Microcomputer 2, 12, 13, 14, 15, 16, 17 ... Transmitter 3 ... Shield case 4, 5, 6, 7, 8, 9, 19 ... Receiver 10 ... Inverter circuit 11 ... Motor 20 ... Modulation Circuit 21... High-frequency amplifier circuit 22, 22 ′ Antenna 23, 24, 25, 26, 27, 28, 29 ... Oscillator 30 ... Amplitude modulation circuit 31. , 81, 82, 91, 92 ... tuning circuits 43, 53, 63, 73, 83, 93 ... demodulator circuits Dup, Dvp, Dwp, Dun, Dvn, Dwn ... driver circuits dup, dvp, dwp, dun, dvn, dwn ... Diode HV ... High voltage power supply Iup, Ivp, Iwp, Iun, Ivn, Iwn ... Overcurrent detection circuit LV ... Low voltage power supply Tr (UP), Tr (VP), Tr (WP), Tr (UN), Tr (VN) , Tr (WN) ... IGBT

Claims (5)

In an insulating device having insulating means for insulating input / output signals between a first circuit connected to a high-voltage power supply and a second circuit connected to a low-voltage power supply,
The insulating means includes
One or more transmitters for transmitting output signals of the first circuit or the second circuit;
An insulating device comprising: a plurality of or one receiver connected to the second circuit or the first circuit and receiving a signal transmitted from the transmitter. The insulation device according to claim 1, wherein
The transmission frequency of the signal transmitted by the plurality of transmitters is different from the transmission frequency of other transmitters in the odd multiple of the frequency.
An insulating device characterized in that an odd multiple of the reception frequency of signals received by the plurality of receivers is different from the reception frequency of other receivers. The insulation device according to claim 2, wherein
The first circuit includes a plurality of power semiconductor switching elements that switch a high voltage supplied from a high-voltage power supply,
The second circuit includes a microcomputer that controls on / off of the power semiconductor switching element,
The power semiconductor switching element on / off control signal output from the microcomputer is transmitted from one transmitter, and the on / off control signals are provided by a plurality of receivers provided corresponding to the plurality of power semiconductor switching elements. An insulating device receiving each control signal. The insulation device according to claim 2, wherein
The first circuit detects a plurality of power semiconductor switching elements that switch a high voltage supplied from a high-voltage power source, and that a current flowing through each of the plurality of power semiconductor switching elements is an overcurrent. A plurality of overcurrent detection circuits,
The second circuit includes a microcomputer that receives overcurrent information of the power semiconductor switching element,
The overcurrent detection signal output from the overcurrent detection circuit is transmitted from a plurality of transmitters provided corresponding to each of the plurality of overcurrent detection circuits, and is provided in the first circuit. The insulation apparatus receives the overcurrent detection by a receiver. The insulation device according to claim 1, wherein
The insulating device according to claim 1, wherein the transmitter is mounted on one surface of the substrate, and the receiver is mounted on the other surface of the substrate.

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