JP2014017923A - Circuit controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit controller capable of monitoring the operating state of a conversion circuit even if a high voltage outputted from the conversion circuit has abnormality.SOLUTION: A high-voltage region H and low-voltage region L are insulated from each other, but they are connected by a transformer 50. The transformer 50 converts a low voltage supplied from a low-voltage power supply 70 existing in the low-voltage region L, and generates a high voltage supplied to a high-voltage-side microcomputer 40 exiting in the high-voltage region H. A low-voltage-side microcomputer exists in the low-voltage region L and monitors the operating state of a transformer 50.

Description

  The present invention relates to a circuit control device.

  A motor for driving a vehicle is mounted on a two-wheel or four-wheel hybrid vehicle, a fuel cell vehicle, an electric vehicle, and the like. This motor is controlled by a high-voltage side circuit that operates at a high voltage supplied from a high-voltage power source, and the auxiliary machine is controlled by a low-voltage side circuit that operates at a low voltage supplied from a low-voltage power source. These low voltage side circuit and high voltage side circuit need to be insulated.

  By the way, the output of the low-voltage power supply may be converted into a high voltage to operate the high-voltage side circuit. For example, Patent Document 1 discloses that an insulation transformer power supply is provided that converts the output of a low-voltage power supply into a high voltage and supplies it to a motor control circuit and a drive circuit.

  However, the control unit of the low-voltage side circuit (low-voltage side microcomputer) and the control unit of the high-voltage side circuit (high-voltage side microcomputer) perform signal transmission through the insulating element, so that the high voltage converted from the output of the low-voltage power supply If there is an abnormality, there is a risk of erroneous transmission due to a malfunction of the insulating element or the like. Therefore, it is necessary to monitor whether or not there is an abnormality in the high voltage converted from the output of the low-voltage power supply.

  Thus, for example, Patent Document 2 discloses a technique for detecting voltage abnormality of an isolator that is an insulating element. In this technique, voltage monitoring circuits are provided on both sides of the isolator, and a photocoupler that is an insulating element is provided between the voltage monitoring circuits.

JP 2008-17595 A JP 2010-116042 A

  However, in the technique disclosed in the cited document 2, the voltage monitoring circuit for detecting an abnormality on the high voltage side is provided on the high voltage side and operates with a high voltage obtained by converting the output of the low voltage power source. Therefore, when there is an abnormality in the converted high voltage, there is a possibility that the abnormality on the high voltage side cannot be detected.

  In view of the above, an object of the present invention is to provide a circuit control device capable of monitoring the operating state of a conversion circuit even when there is an abnormality in the high voltage output from the conversion circuit.

  The circuit control device of the present invention is a circuit control device comprising a high voltage region and a low pressure region that are insulated from each other, and an insulating element that connects the high pressure region and the low pressure region, the low voltage region existing in the low pressure region A conversion circuit that converts a low voltage supplied from a power source to generate a high voltage to be supplied to a circuit that exists in the high-voltage region; and a monitoring unit that exists in the low-voltage region and monitors the operating state of the conversion circuit; It is characterized by providing.

  According to the present invention, the monitoring means for monitoring the operating state of the conversion circuit exists in the low voltage region and operates at a low voltage supplied from the low voltage power source. Therefore, even if there is an abnormality in the high voltage output from the conversion circuit, the monitoring unit can monitor the operating state of the conversion circuit.

1 is a block diagram showing an overall configuration of an inverter system according to a first embodiment of the present invention. The block diagram which shows the whole structure of the inverter system which concerns on the 2nd Embodiment of this invention.

  An inverter system 100 including a circuit control device according to a first embodiment of the present invention will be described with reference to the drawings. The inverter system 100 is mounted on, for example, a two-wheel or four-wheel hybrid vehicle, a fuel cell vehicle, an electric vehicle, and the like.

  As shown in FIG. 1, an inverter system 100 includes a motor 10, a high voltage power source (high voltage battery) 20, a PDU (power drive unit) 30, a high voltage side microcomputer (lower microcomputer) 40, a transformer 50, a control IC 60, a low voltage power source (low voltage battery). ) 70, a low-voltage side microcomputer (high-order microcomputer) 80, and the like. The PDU 30, the high voltage side microcomputer 40, the transformer 50, and the control IC 60 are mounted on the substrate 90.

  The PDU 30 and the high voltage side microcomputer 40 are arranged in a high voltage side region H (hereinafter referred to as a high voltage region) H from the insulation boundary indicated by the alternate long and short dash line, and are driven by the high voltage power supply 20. The control IC 60 and the low voltage side microcomputer 80 are disposed in a low voltage side region (hereinafter referred to as a low voltage region) L from the insulation boundary and are driven by the low voltage power source 70.

  Although the high voltage region H and the low voltage region L are insulated from each other, the high voltage side microcomputer 40 existing in the high voltage region H is connected to the control IC 60 existing in the low voltage region L via the transformer 50. Thus, the transformer 50 connects the high voltage region H and the low voltage region L, and corresponds to an insulating element of the present invention.

  The high-voltage power source 20 is a high-voltage DC power source used as a power source during vehicle electric travel, and is connected to the PDU 30 via a smoothing circuit 31. The low-voltage power source 70 is a low-voltage DC power source used as a power source for vehicle auxiliary equipment, and is connected to the transformer 50, the control IC 60, and the low-voltage side microcomputer 80.

  Although not shown in detail, the motor 10 is, for example, a three-phase brushless DC motor, and includes a rotor having a plurality of permanent magnets and a plurality of phases (for example, a U phase and a V phase) that generate a rotating magnetic field that rotates the rotor. , W-phase three-phase) stator.

  Although not shown in detail, the PDU 30 includes a bridge circuit formed by bridge-connecting a plurality of switching elements including semiconductor devices such as IGBTs and diodes, and a smoothing capacitor. Pulse width modulation (PWM) The PWM inverter which performs is provided.

  The PDU 30 receives the control signal (gate signal) output from the PMW signal generation circuit 32 and drives the motor 10 and performs a regenerative operation.

  For example, when the motor 10 is driven, the PDU 30 converts the DC power supplied from the high-voltage power supply 20 into three-phase AC power by switching the on / off state of each transistor of the PWM inverter based on the control signal. AC current is supplied to the motor 10 by the PWM energization.

  Further, the PDU 30 turns on / off each transistor of the PWM inverter in accordance with a control signal synchronized with the output waveform of the rotation angle of the motor 10 when charging the high-voltage power supply 20, for example, during regenerative operation of the motor 10. The three-phase AC power output from the motor 10 is converted into DC power and output to the high-voltage power supply 20.

  The PMW signal generation circuit 32 generates a control signal (PMW signal) for turning on / off a switching element (for example, MOSFET, IGBT) constituting the PDU 30 by PWM control from the three-phase voltage.

  The high voltage side microcomputer 40 performs current control on the dq coordinates forming the rotation orthogonal coordinates. The high voltage side microcomputer 40 calculates each phase AC voltage command value based on the Id command and the Iq command, and outputs it to the PMW signal generation circuit 32. Specifically, the high-voltage side microcomputer 40 has a d-axis current Id and a q-axis current Iq obtained by converting each phase current actually supplied from the PDU 30 to the motor 10 on the dq coordinate, and an Id command and an Iq command. Control is performed so that each deviation becomes zero. The control of the motor 10 may be voltage control.

  The transformer 50 is, for example, a separately-excited (flyback) transformer, and converts the input voltage input to the primary side (low voltage side) of the transformer 50 into an output voltage of a predetermined high voltage level, and converts it to the secondary side ( The high voltage side microcomputer 40 is connected to the high voltage side microcomputer 40 via the rectifier circuit 41. The transformer 50 may be self-excited.

  Thus, the transformer 50 converts the low voltage supplied from the low voltage power supply 70 to a high voltage in order to operate the high voltage side microcomputer 40 and the like existing in the high voltage region, and corresponds to the conversion circuit of the present invention. To do.

  A switching circuit 61 for turning on / off current is connected to the primary side of the transformer 50. The switching circuit 61 is composed of a switching element such as a power MOSFET.

  The control IC 60 supplies a drive signal (gate signal) to the switching circuit 61 and controls the switching operation of the switching circuit 61. The control IC 60 controls the switching operation by, for example, PWM control for turning on / off the switching circuit 61 with a duty ratio corresponding to the input voltage, and generates a predetermined output voltage on the secondary side of the transformer 50.

  With the switching operation of the switching circuit 61, a current change occurs on the primary side of the transformer 50, and an electromotive force is induced on the secondary side with this current change, and an output voltage is supplied to the high-voltage side microcomputer 40 via the rectifier circuit 41. Supplied.

  Further, the inverter system 100 includes a configuration in the low voltage region L for performing feedback control of the output voltage supplied to the high voltage side microcomputer 40. Specifically, a feedback voltage circuit 91 that outputs a feedback signal having a voltage level corresponding to the output voltage is provided in the low voltage region L.

  The feedback voltage circuit 91 outputs a feedback signal having a voltage (feedback voltage) corresponding to the voltage level of the output voltage. The electromotive force induced by the change in current on the secondary side of the transformer 50 is smoothed and converted to direct current by the rectifier circuit 92 and input to the feedback voltage circuit 91.

  Further, in the low voltage region L, a feedback adjustment circuit 93, an error voltage adjustment circuit 94, a frequency adjustment circuit 95, a soft start circuit 96, and a start voltage adjustment circuit 97 are provided. A feedback signal from the feedback voltage circuit 91 is input to the feedback adjustment circuit 93 and the error voltage adjustment circuit 94.

  The feedback adjustment circuit 93 calculates the adjustment value of the duty ratio of the PWM control based on the feedback signal so that the output voltage is maintained at a constant voltage level, and outputs it to the control IC 60. The control IC 60 dynamically varies the duty ratio of the PWM control based on the adjustment value of the feedback adjustment circuit 93, so that even if the input voltage fluctuation on the primary side or the load fluctuation on the secondary side occurs, The output voltage can be kept constant.

  The error voltage adjustment circuit 94 detects whether or not the voltage level of the output voltage is within a predetermined range, and outputs a detection signal to the control IC 60. When the voltage level of the output voltage exceeds a predetermined range, the control IC 60 stops the switching operation of the switching circuit 61.

  The frequency adjustment circuit 95 generates a clock signal of a drive signal used for PWM control, adjusts the pulse frequency of the clock signal, and outputs the adjusted signal to the control IC 60.

  The soft start circuit 96 is configured to gradually increase the pulse width of the drive signal to the switching circuit 61 until the output voltage is stabilized by feedback control by the control IC 60 in order to prevent an inrush current at the start. The control IC 60 is controlled so that the output voltage is ramped substantially linearly and soft-started.

  The starting voltage adjusting circuit 97 adjusts the starting voltage at which the control IC 60 starts operating when the input voltage is input. That is, the voltage range of the drive signal of the switching circuit 61 includes a region where the switching circuit 61 can operate but the on-resistance is high and the loss is increased. When the input voltage is in such a region, the starting voltage adjusting circuit 97 adjusts the starting voltage so that the control IC 60 does not operate, and suppresses the driving of the switching circuit 61 in this voltage range.

  In the inverter system 100 configured as described above, the low voltage side microcomputer 80 monitors the operating state of the transformer 50. Specifically, the low-voltage side microcomputer 80 monitors the operating state of the transformer 50 by monitoring a drive signal to the transformer 50, that is, a drive signal supplied from the control IC 60 to the switching circuit 61. The low voltage side microcomputer 80 corresponds to the monitoring means of the present invention.

  If an abnormal drive signal is input to the transformer 50, the transformer 50 can be regarded as operating abnormally. On the other hand, if a normal drive signal is input to the transformer 50, it can be considered that the transformer 50 is operating normally. Therefore, the low voltage side microcomputer 80 can detect whether or not the transformer 50 is operating normally by monitoring the drive signal to the transformer 50.

  In the inverter system 100, the low-voltage side microcomputer 80 operates with a low voltage supplied from the low-voltage power supply 70, so that even if there is an abnormality in the high voltage output from the transformer 50, the operating state of the transformer 50 is normally monitored. be able to.

  Further, as disclosed in the above cited document 2, it is possible to monitor whether or not there is an abnormality in the high voltage output from the transformer 50 without providing additional parts such as an insulating element. Therefore, an increase in cost and the number of parts can be suppressed. If an insulation amplifier (isolation amplifier) or the like is used, it is possible to detect the high voltage output from the transformer 50 and monitor it on the low voltage side. However, such an insulation amplifier is expensive because it is expensive. Cost increases and the number of parts increases.

  Furthermore, since the drive signal to the transformer 50 is monitored, the abnormality can be detected in advance before the transformer 50 actually outputs an abnormal high voltage. Therefore, it becomes possible to stop the operation of the transformer 50 before the abnormality occurs.

  Next, an inverter system 200 including a circuit control device according to a second embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, this inverter system 200 is the same as the above-described inverter system 100 except that an amplifier 101 is added, and only the differences will be described.

  The amplifier 101 is provided in the low voltage region L and adjusts so that the voltage value of the feedback signal output from the feedback voltage circuit 91 falls within a predetermined voltage range allowed by the low voltage side microcomputer 80. The amplifier 101 is not an insulating type.

  Also in the inverter system 200 configured as described above, the low voltage side microcomputer 80 monitors the operating state of the transformer 50. Specifically, the low-voltage side microcomputer 80 monitors the drive signal to the transformer 50, that is, the drive signal supplied from the control IC 60 to the switching circuit 61, and monitors the feedback signal, thereby operating the transformer 50. To monitor.

  In the inverter system 100 described above, when the transformer 50 or the switching circuit 61 is broken due to a short circuit or the like, even if the high voltage output from the transformer 50 is abnormal, it may not be detected.

  By the way, as described above, the control IC 60 uses the feedback signal output from the feedback voltage circuit 91 in accordance with the voltage level of the output voltage from the transformer 50 to keep the output voltage constant even when the load on the output side fluctuates. It is controlled to hold. However, if the transformer 50 or the switching circuit 61 is overloaded, for example, even if the duty ratio of the switching circuit 61 is maximized, a predetermined output voltage cannot be output from the transformer 50, and the voltage value of the feedback signal is descend.

  Therefore, the inverter system 200 detects whether or not there is an abnormality in the voltage generated by the transformer 50 by also monitoring the feedback signal. If a feedback signal having an abnormal voltage value is detected, it can be considered that the high voltage output from the transformer 50 is abnormal.

  In the inverter system 200 as well, as in the inverter system 100 described above, the low-voltage side microcomputer 80 operates at a low voltage supplied from the low-voltage power supply 70, so even if there is an abnormality in the high voltage output from the transformer 50, The operating state of the transformer 50 can be monitored normally.

  Further, as disclosed in the above cited document 2, since an inexpensive non-insulating amplifier 101 is added without providing an expensive additional component such as an insulating element, the output from the transformer 50 is reduced in cost. It is possible to monitor whether there is any abnormality in the high voltage.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 20 ... High voltage power supply, 30 ... PDU, 32 ... PMW signal generation circuit, 40 ... High voltage side microcomputer (circuit), 50 ... Transformer (insulation element, conversion circuit), 60 ... Control IC, 61 ... Switching circuit, 70 ... Low voltage power supply, 80 ... Low voltage side microcomputer (monitoring means), 90 ... Substrate, 91 ... Feedback voltage circuit, 93 ... Feedback adjustment circuit, 94 ... Error voltage adjustment circuit, 95 ... Frequency adjustment circuit, 96 ... Soft start circuit, 97: Start-up voltage adjusting circuit, 100, 200: Inverter system (circuit control device), 101: Amplifier, H: High voltage region, L: Low voltage region

Claims (1)

A circuit control device comprising a high pressure region and a low pressure region that are insulated from each other, and an insulating element that connects the high pressure region and the low pressure region,
A conversion circuit that converts a low voltage supplied from a low-voltage power source existing in the low-voltage region and generates a high voltage supplied to a circuit existing in the high-voltage region;
A circuit control apparatus, comprising: a monitoring unit that exists in the low-pressure region and that monitors an operating state of the conversion circuit.

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