JP2016201914A - Semiconductor device, transformation device, and power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device capable of properly detecting that an output current value or an output voltage value of a transformation circuit, which is indicated by a detection result, is smaller than an actual value, and to provide a transformation device and a power supply system comprising the semiconductor device.SOLUTION: A transformation circuit 20 transforms a voltage inputted via a resistor R4, and outputs the transformed voltage via a resistor R1. A microcomputer 21 detects abnormalities related to the transformation circuit 20. Respective current detectors 22 and 23 detect an output current value and an input current value of the transformation circuit 20. Respective voltage detectors 24 and 25 detect an output voltage value and an input voltage value of the transformation circuit 20. A controller 52 calculates an index value related to an efficiency of the transformation performed by the transformation circuit 20 on the basis of the detection results of the current detectors 22 and 23 and the voltage detectors 24 and 25, and determines whether or not the efficiency indicated by the calculated index value is less than a predetermined efficiency.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a semiconductor device that detects an abnormality related to a transformer circuit that transforms an input voltage and outputs the transformed voltage, and a transformer device and a power supply system including the semiconductor device.

  As a power supply system mounted on a vehicle, a generator that converts the kinetic energy of the vehicle into DC regenerative power, and a transformer that transforms the DC voltage related to the regenerative power converted by the generator and outputs the transformed voltage to the capacitor. A power supply system including a circuit has been proposed (see, for example, Patent Document 1).

  The power supply system described in Patent Document 1 further includes a semiconductor device having a CPU (Central Processing Unit). The semiconductor device causes the transformer circuit to perform transformation when the generator outputs a DC voltage related to the regenerative power as an output voltage. When the semiconductor device causes the transformer circuit to transform, a voltage is applied to the capacitor, and the capacitor stores electric power. The electric power stored in the battery is supplied to a load mounted on the vehicle.

JP 2009-213246 A

  As a power supply system as described in Patent Document 1, a current detector that detects a value related to an output current value flowing from a transformer circuit to a capacitor is provided, and an output current value indicated by a detection result of the current detector is a predetermined current. There is a power supply system in which a semiconductor device controls an output voltage value output from a transformer circuit to a capacitor so as to be a value.

  In this power supply system, when the output current value indicated by the detection result of the current detector is smaller than the actual output current value, the semiconductor device has a current value larger than the predetermined current value described above. Thus, the output voltage value output from the transformer circuit is controlled. For this reason, the semiconductor device may continue to output an excessive voltage to the capacitor in the transformer circuit.

  Moreover, as a power supply system as described in Patent Document 1, a voltage detector that detects a value related to an output voltage value output from a transformer circuit to a capacitor is provided, and an output voltage value indicated by a detection result of the voltage detector There is also a power supply system in which the semiconductor device controls the actual output voltage value so that becomes a predetermined voltage value.

  Even in this power supply system, when the output voltage value indicated by the detection result of the voltage detector is lower than the actual output voltage value, the semiconductor device has a voltage value in which the actual output voltage value is higher than the predetermined voltage value described above. Control to be For this reason, the semiconductor device may continue to output an excessive voltage to the capacitor in the transformer circuit.

  When an excessive voltage is continuously output from the transformer circuit to the capacitor, the performance of the capacitor, for example, the capacity of the capacitor may be reduced. In order to prevent an excessive voltage from being continuously output from the transformer circuit, it is necessary to appropriately detect that the output current value or the output voltage value indicated by the detection result is lower than the actual value.

  The present invention has been made in view of such circumstances, and its purpose is to properly detect that the output current value or output voltage value of the transformer circuit indicated by the detection result is smaller than the actual value. It is an object to provide a semiconductor device that can be used, and a transformer device and a power supply system including the semiconductor device.

  The semiconductor device according to the present invention is an input current detector for detecting a value related to an input current value of the transformer circuit in a semiconductor device for detecting an abnormality relating to a transformer circuit that transforms an input voltage and outputs the transformed voltage. An input voltage detector for detecting a value relating to the input voltage value of the transformer circuit, an output current detector for detecting a value relating to the output current value of the transformer circuit, and a value relating to the output voltage value of the transformer circuit Based on the detection result of the output voltage detector to be detected, a calculation unit that calculates an index value related to the efficiency of transformation performed by the transformer circuit, and whether the efficiency indicated by the index value calculated by the calculation unit is less than a predetermined efficiency And an efficiency determination unit for determining whether or not.

  In the present invention, an input current detector, an input voltage detector, an output current detector, and an output voltage detector that detect an input current value, an input voltage value, an output current value, and an output voltage value of a transformer circuit, respectively. Based on the result, an index value related to the efficiency of the transformation performed by the transformer circuit is calculated. It is determined whether or not the efficiency indicated by the calculated index value is less than a predetermined efficiency. Thereby, the abnormality regarding a transformer circuit is detected.

  When the output current value indicated by the detection result of the output current detector or the output voltage value indicated by the detection result of the output voltage detector is smaller than the actual value, the transformation efficiency indicated by the index value is less than the predetermined efficiency. It is judged and it is appropriately detected that the output current value or output voltage value of the transformer circuit indicated by the detection result is lower than the actual value.

  The semiconductor device according to the present invention includes the input current value, the input voltage value, the output current value, and the output voltage value indicated by the detection results of the input current detector, the input voltage detector, the output current detector, and the output voltage detector, respectively. Is Iin, Vin, Iout and Vout, the index value is (Iout− (Iin × Vin / Vout)) / Iout.

  In the present invention, the index value is (Iout− (Iin × Vin / Vout)) / Iout. By expansion, the equation is expressed as 1− (Iin × Vin) / (Iout × Vout). The efficiency of the transformation is (Iout × Vout) / (Iin × Vin), which is not less than zero and not more than 1. (Iin × Vin) / (Iout × Vout) is smaller as the transformation efficiency is higher and is 1 or more. Therefore, the index value is larger as the efficiency of transformation is higher, and is less than zero. When the index value is less than the predetermined value, the efficiency of the transformation performed by the transformer circuit is less than the predetermined efficiency.

  In the semiconductor device according to the present invention, when it is determined that the output current value indicated by the detection result of the output current detector exceeds the current threshold, the calculation unit calculates the index value, and the efficiency determination The section is characterized by making a determination.

  In the present invention, when it is determined that the output current value indicated by the detection result of the output current detector exceeds the current threshold, the index value is calculated, and the efficiency indicated by the calculated index value is less than the predetermined efficiency. It is determined whether or not there is. In the transformer circuit, when the actual output current value is small, the efficiency of the actual transformation is usually low. For this reason, even if the detection results of the input current detector, the input voltage detector, the output current detector, and the output voltage detector are appropriate, the efficiency indicated by the index value may be less than the predetermined efficiency. In the present invention, since the index value is calculated when the output current value exceeds the current threshold, the probability of erroneous detection is low.

  The semiconductor device according to the present invention includes a stop unit that stops transformation of the transformer circuit when the efficiency determination unit determines that the efficiency is less than the predetermined efficiency.

  In the present invention, when it is determined that the efficiency of the transformation indicated by the calculated index value is less than the predetermined efficiency, the transformation of the transformer circuit is stopped. For this reason, for example, an excessive voltage is not continuously output from the transformer circuit due to the difference between the value indicated by the detection result of the output current detector or the output voltage detector and the actual value.

  In the semiconductor device according to the present invention, the calculation unit repeatedly calculates the index value, and the efficiency determination unit determines whether the efficiency is less than the predetermined efficiency each time the calculation unit calculates the index value. The stopping unit stops the transformation of the transformer circuit when the efficiency determining unit continuously determines that the efficiency is less than the predetermined efficiency a plurality of times.

  In the present invention, the index value is repeatedly calculated, and each time the index value is calculated, it is determined whether or not the efficiency indicated by the calculated index value is less than a predetermined efficiency. When it is determined that the efficiency indicated by the calculated index value is less than the predetermined efficiency, the transformation of the transformer circuit is stopped. Therefore, when there is a high probability that an abnormality relating to the control of the operation of the transformer circuit has occurred, the transformation of the transformer circuit is stopped.

  A transformer device according to the present invention includes the semiconductor device described above, and the transformer circuit, an input voltage detector, an input current detector, an output voltage detector, and an output current detector.

  In the present invention, the semiconductor device detects an abnormality related to the transformer circuit based on the detection results of the input voltage detector, the input current detector, the output voltage detector, and the output current detector.

  A power supply system according to the present invention includes the above-described transformer device and a capacitor to which a voltage output from the transformer circuit is applied.

  In the present invention, the voltage output from the other end of the transformer circuit of the transformer device is applied to the capacitor, and the capacitor is charged.

  According to the present invention, it is possible to appropriately detect that the output current value or output voltage value of the transformer circuit indicated by the detection result is lower than the actual value.

It is a block diagram which shows the principal part structure of the power supply system in this Embodiment. It is a block diagram which shows the principal part structure of a DCDC converter. It is a timing chart for demonstrating the charging process which a control part performs. It is a flowchart which shows the procedure of the 1st detection process which a control part performs. It is a flowchart which shows the procedure of the 1st detection process which a control part performs.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a block diagram showing a main configuration of a power supply system 1 according to the present embodiment. The power supply system 1 is suitably mounted on a vehicle, and includes a DCDC converter 10, a first capacitor 11, a second capacitor 12, a generator 13, a load 14, and a notification unit 15. The DCDC converter 10 has a first end, a second end, and a third end.

  Regarding the DCDC converter 10, the first end is connected to the positive electrode of the second battery 12, the second end is connected to the positive electrode of the first battery 11, one end of each of the generator 13 and the load 14, and the third end is It is connected to the notification unit 15. The negative electrodes of the first capacitor 11 and the second capacitor 12 and the other ends of the generator 13 and the load 14 are grounded.

  The DCDC converter 10 is input with a charge instruction for instructing charging of the second battery 12, a discharge instruction for instructing discharge of the second battery 12, and a stop instruction for instructing stop of transformation. The DCDC converter 10 further receives an ignition signal indicating whether or not an ignition switch (not shown) of the vehicle on which the power supply system 1 is mounted is on or off. The ignition switch is on while the engine (not shown) of the vehicle is operating, and the ignition switch is off while the engine stops operating.

  When a charging instruction is input, the DCDC converter 10 transforms the voltage applied to the second terminal to which the first capacitor 11 and the generator 13 are connected, and the transformed voltage is transferred from the first terminal to the second capacitor. 12 is output.

When a discharge instruction is input, the DCDC converter 10 transforms the voltage applied to the first terminal to which the second capacitor 12 is connected, and the transformed voltage is transmitted from the second terminal to the first capacitor 11 and the load 14. Output to.
The DCDC converter 10 stops the transformation when the stop instruction is input. Thereby, charging or discharging of the second battery 12 is stopped.

The DCDC converter 10 detects an abnormality relating to a transformer circuit 20 (see FIG. 2) described later that performs the above-described transformation. When the DCDC converter 10 detects this abnormality, the transformer circuit 20 stops the transformation, and does not resume the transformation until the ignition signal indicates that the ignition switch is turned off and turns on again. Moreover, when the DCDC converter 10 detects an abnormality related to the transformer circuit 20, the DCDC converter 10 outputs a notification signal indicating that the abnormality has occurred to the notification unit 15 from the third end.
When the notification signal is input, the notification unit 15 notifies that an abnormality relating to the transformer circuit 20 has occurred by lighting a lamp (not shown) or displaying a message on a display unit (not shown). Thereby, the user can be prompted to repair the power supply system 1.

  The second battery 12 is, for example, an electric double layer capacitor. The voltage output from the first end of the DCDC converter 10 is applied across the second capacitor 12, and the second capacitor 12 is charged. When no voltage is output from the first end of the DCDC converter 10, the second battery 12 applies the output voltage to the first end of the DCDC converter 10. The DCDC converter 10 transforms the output voltage of the second battery 12 when a discharge instruction is input. As a result, the second battery 12 is discharged.

  The first battery 11 is, for example, a lead storage battery. When the DCDC converter 10 outputs a voltage from the second end, or when the generator 13 generates power, a voltage is applied between both ends of the first capacitor 11, and the first capacitor 11 is charged. . When the DCDC converter 10 does not output a voltage from the second end and the generator 13 does not generate power, the first capacitor 11 outputs the output voltage to the second end of the DCDC converter 10 and the load 14. Apply to one end.

  The generator 13 converts the kinetic energy of the vehicle into AC regenerative power when, for example, a brake pedal (not shown) is depressed while an accelerator pedal (not shown) is not depressed, and the vehicle is decelerating. . The generator 13 rectifies AC regenerative power into DC regenerative power, and uses the DC voltage related to the rectified regenerative power as an output voltage, the second end of the DCDC converter 10, the positive electrode of the first capacitor 11, Applied to one end of the load 14.

  The load 14 is an electric device mounted on the vehicle. The voltage output from the second end of the DCDC converter 10, the output voltage of the first battery 11, or the output voltage of the generator 13 is applied between both ends of the load 14. Thereby, the load 14 is supplied with power.

  FIG. 2 is a block diagram showing a main configuration of the DCDC converter 10. The DCDC converter 10 includes a transformer circuit 20, a microcomputer (hereinafter referred to as a microcomputer) 21, current detectors 22 and 23, and voltage detectors 24 and 25.

  The transformer circuit 20 is connected to the microcomputer 21 and the current detectors 22 and 23 separately. The current detector 22 is connected to the positive electrode of the second battery 12 and the microcomputer 21 separately. The voltage detector 24 is connected to the connection node between the second battery 12 and the current detector 22 and to the microcomputer 21 separately. The voltage detector 24 is grounded. The current detector 23 is connected to the positive electrode of the first battery 11 and the microcomputer 21 separately. The voltage detector 25 is connected to the connection node between the first capacitor 11 and the current detector 23 and the microcomputer 21 separately. The voltage detector 25 is grounded.

  When the second battery 12 is charged, current flows in the order of the current detector 23, the transformer circuit 20, and the current detector 22. When the second battery 12 is discharged, current flows in the order of the current detector 22, the transformer circuit 20, and the current detector 23.

The transformer circuit 20 transforms the voltage input via the current detector 23, and outputs the transformed voltage to the second capacitor 12 via the current detector 22. As a result, the voltage output from the first end of the DCDC converter 10 by the transformer circuit 20 is applied between both ends of the second capacitor 12, and the second capacitor 12 is charged.
Further, the transformer circuit 20 transforms the voltage input via the current detector 22 and outputs the transformed voltage to the first capacitor 11 and the load 14 via the current detector 23. As a result, the second battery 12 is discharged.

  The current detector 22 includes a resistor R1 and a differential amplifier 30. One end of the resistor R1 is connected to the transformer circuit 20. The other end of the resistor R1 corresponds to the first end of the DCDC converter 10 and is connected to the positive electrode of the second battery 12 and the voltage detector 24. A positive terminal and a negative terminal of the differential amplifier 30 are connected to one end and the other end of the resistor R1, respectively. The output terminal of the differential amplifier 30 is connected to the microcomputer 21.

  A current flows from the transformer circuit 20 to the first end of the DCDC converter 10 via the resistor R1. In addition, current flows from the first end of the DCDC converter 10 to the transformer circuit 20 via the resistor R1. The differential amplifier 30 amplifies the voltage value across the resistor R1 and outputs the amplified voltage value Vi1 to the microcomputer 21. Thus, the current detector 22 detects the voltage value Vi1.

  The resistance value of the resistor R1 is a constant value, and the voltage value Vi1 output from the differential amplifier 30 is a value related to the current value Ic flowing through the resistor R1. The current value Ic is positive when current flows from the transformer circuit 20 to the first end of the DCDC converter 10, and negative when current flows from the first end of the DCDC converter 10 to the transformer circuit 20. . The voltage value Vi1 is higher as the current value Ic is larger.

  Specifically, the voltage value Vi1 is a predetermined voltage value when the current value Ic is zero amperes. When the current value Ic is positive, it exceeds a predetermined voltage value, and the voltage value Vil is higher as the current value Ic is larger. When the current value Ic is negative, the voltage value Vil is lower as the absolute value of the current value Ic is smaller than the predetermined voltage value. Here, the predetermined voltage value is not limited to zero volts, and may be a value exceeding zero volts, for example, 3 volts.

  The voltage detector 24 has resistors R2 and R3. One end of the resistor R2 is connected to the other end of the resistor R1, that is, the first end of the DCDC converter 10. The other end of the resistor R2 is connected to one end of the resistor R3. The other end of the resistor R3 is grounded. The connection node of the resistors R2 and R3 is connected to the microcomputer 21.

The resistors R2 and R3 divide the voltage at the first end of the DCDC converter 10 and output the divided voltage to the microcomputer 21. The voltage value V <b> 1 output from the voltage detector 24 to the microcomputer 21 is a first constant of the voltage value Vc at the first end of the DCDC converter 10, for example, 1/10. The voltage value V1 is a value related to the voltage value Vc. Since the combined resistance value of the resistors R2 and R3 is sufficiently large, almost no current flows from the first end of the DCDC converter 10 to the resistors R2 and R3.
As described above, the voltage detector 24 functions as a detector that detects the voltage value V1.

  The current detector 23 includes a resistor R4 and a differential amplifier 31. One end of the resistor R4 is connected to the transformer circuit 20. The other end of the resistor R4 corresponds to the second end of the DCDC converter 10 and is connected to the positive electrode of the first capacitor 11 and the voltage detector 25. The positive terminal and the negative terminal of the differential amplifier 31 are connected to one end and the other end of the resistor R4, respectively. The output terminal of the differential amplifier 31 is connected to the microcomputer 21.

  A current flows from the transformer circuit 20 to the second end of the DCDC converter 10 via the resistor R4. In addition, current flows from the second end of the DCDC converter 10 to the transformer circuit 20 via the resistor R4. The differential amplifier 31 amplifies the voltage value across the resistor R4 and outputs the amplified voltage value Vi2 to the microcomputer 21. Thus, the current detector 23 detects the voltage value Vi2.

  The resistance value of the resistor R4 is a constant value, and the voltage value Vi2 output from the differential amplifier 31 is a value related to the current value Ib flowing through the resistor R4. The current value Ib is positive when current flows from the transformer circuit 20 to the second end of the DCDC converter 10, and is negative when current flows from the second end of the DCDC converter 10 to the transformer circuit 20. . The relationship between the voltage value Vi2 and the current value Ib is similar to the relationship between the voltage value Vi1 and the current value Ic, and the voltage value Vi2 is higher as the current value Ib is larger.

  The voltage detector 25 has resistors R5 and R6. One end of the resistor R5 is connected to the other end of the resistor R4, that is, the second end of the DCDC converter 10. The other end of the resistor R5 is connected to one end of the resistor R6. The other end of the resistor R6 is grounded. The connection node of the resistors R5 and R6 is connected to the microcomputer 21.

The resistors R5 and R6 divide the voltage at the second end of the DCDC converter 10 and output the divided voltage to the microcomputer 21. The voltage value V2 output from the voltage detector 25 to the microcomputer 21 is a second constant of the voltage value Vb at the second end of the DCDC converter 10, for example, 1/10. The voltage value V2 is a value related to the voltage value Vb. Since the combined resistance value of the resistors R5 and R6 is sufficiently large, almost no current flows from the second end of the DCDC converter 10 to the resistors R5 and R6.
As described above, the voltage detector 25 functions as a detector that detects the voltage value V2.

  The transformer circuit 20 includes one or more switches (not shown) and an inductor. The microcomputer 21 operates the transformer circuit 20 by individually turning on and off one or a plurality of switches of the transformer circuit 20 so that a current flows through the inductor. In addition, the microcomputer 21 causes the transformer circuit to stop operating by individually turning on and off one or more switches of the transformer circuit 20 so that no current flows through the inductor. Further, the microcomputer 21 adjusts the direction of the current flowing through the inductor and the value of the current flowing through the inductor by individually turning on and off one or more switches of the transformer circuit 20. The voltage value Vc or Vb output via the current detector 22 or 23 is controlled.

The microcomputer 21 receives a charge instruction, a discharge instruction, a stop instruction, and an ignition signal. The microcomputer 21 is based on the input charge instruction, discharge instruction, stop instruction, and ignition signal, and the voltage values Vi1, Vi2, V1, V2 input from the current detectors 22, 23 and the voltage detectors 24, 25. The operation of the transformer circuit 20 is controlled. The microcomputer 21 is configured to detect an abnormality related to the transformer circuit 20. When detecting this abnormality, the microcomputer 21 outputs a notification signal to the notification unit 15. The abnormality assumed for the transformer circuit 20 is at least current values Ic, Ib and voltage values Vc, Vb indicated by voltage values Vi1, Vi2, V1, V2 detected by the current detectors 22, 23 and the voltage detectors 24, 25. One is less than the actual value.
The microcomputer 21 is configured using a semiconductor element and functions as a semiconductor device. The DCDC converter 10 functions as a transformer device.

  The microcomputer 21 includes a drive unit 40, input units 41, 42, 43, 44, and 45, A (Analog) / D (Digital) conversion units 46, 47, 48, and 49, an output unit 50, a storage unit 51, and a control unit 52. Have The drive unit 40, the input unit 45, the A / D conversion units 46, 47, 48, 49, the output unit 50, the storage unit 51, and the control unit 52 are connected to the bus 53. The drive unit 40 is connected to the transformer circuit 20 in addition to the bus 53. Each of the A / D converters 46, 47, 48, 49 is connected to the input units 41, 42, 43, 44 in addition to the bus 53. The input units 41, 42, 43, and 44 are further connected to the output terminal of the differential amplifier 30, the connection node of the resistors R2 and R3, the output terminal of the differential amplifier 31, and the connection node of the resistors R5 and R6. ing. The output unit 50 is connected to the notification unit 15 in addition to the bus 53.

  The drive unit 40 turns on and off one or more switches of the transformer circuit 20 in accordance with instructions from the control unit 52. The control unit 52 controls the operation and stop of the transformer circuit 20 and the voltage value output by the transformer circuit as described above by causing the drive unit 40 to turn on and off one or more switches.

  Analog voltage values Vi1, V1, Vi2, and V2 are input from the current detector 22, the voltage detector 24, the current detector 23, and the voltage detector 25 to the input units 41, 42, 43, and 44, respectively. The input units 41, 42, 43, and 44 output the input analog voltage values Vi1, V1, Vi2, and V2 to the A / D conversion units 46, 47, 48, and 49, respectively.

  The A / D converter 46 converts the analog voltage value Vi1 input from the input unit 41 into a digital voltage value Vi1. The A / D converter 47 converts the analog voltage value V1 input from the input unit 42 into a digital voltage value V1. The A / D converter 48 converts the analog voltage value Vi2 input from the input unit 43 into a digital voltage value Vi2. The A / D converter 49 converts the analog voltage value V2 input from the input unit 44 into a digital voltage value V2. The digital voltage values Vi1, V1, Vi2, and V2 are acquired by the control unit 52 from the A / D conversion units 46, 47, 48, and 49, respectively.

The input unit 45 receives a charge instruction, a discharge instruction, a stop instruction, and an ignition signal. When a charge instruction, a discharge instruction, or a stop instruction is input, the input unit 45 notifies the control unit 52 to that effect. When the ignition signal is input, the input unit 45 notifies the control unit 52 of the content indicated by the input ignition signal.
The output unit 50 outputs a notification signal to the notification unit 15 in accordance with an instruction from the control unit 52.

  The storage unit 51 is a non-volatile memory, and the storage unit 51 stores a control program. The control unit 52 includes a CPU (not shown) and executes a control program stored in the storage unit 51 to perform a charging process for charging the second battery 12 and a discharging process for discharging the second battery 12. Run. Furthermore, the control part 52 performs the 1st detection process and the 2nd detection process which detect abnormality regarding the transformer circuit 20 by running a control program. The control unit 52 executes the first detection process in parallel with the charging process, and executes the second detection process in parallel with the discharge process.

  FIG. 3 is a timing chart for explaining the charging process executed by the control unit 52. FIG. 3 shows changes in the current value Ic and the voltage value Vc. In the following description of the charging process, the voltage value Vc indicated by the voltage value V1 matches the voltage value Vc output from the transformer circuit 20, and the current value Ic indicated by the voltage value Vi1 flows from the transformer circuit 20. It is assumed that the current value Ic matches.

  The control unit 52 performs a charging process when a charging instruction is input to the input unit 45. In the charging process, the control unit 52 instructs the drive unit 40 to drive the transformer circuit 20. Thereby, charging is started. The transformer circuit 20 transforms the voltage input via the resistor R4 of the current detector 23, and outputs the transformed voltage to the second capacitor 12 via the resistor R1 of the current detector 22. Thereby, a voltage is applied to the second battery 12 and the second battery 12 is charged.

  Further, the control unit 52 instructs the drive unit 40 to increase the voltage value Vc output from the first end of the DCDC converter 10 to the second battery 12 by the transformer circuit 20. Specifically, the control unit 52 determines whether the current value Ic indicated by the voltage value Vi1 acquired from the A / D conversion unit 46 becomes the upper limit current value Icm or the voltage value V1 acquired from the A / D conversion unit 47. The voltage value Vc output from the transformer circuit 20 is increased until the voltage value Vc indicated by becomes the upper limit voltage value Vcm.

  When charging of the second battery 12 is started, the voltage value Vc output from the transformer circuit 20 increases until the current value Ic indicated by the voltage value Vi1 reaches the upper limit current value Icm. Thereafter, the voltage value Vc output from the transformer circuit 20 is maintained such that the current value Ic indicated by the voltage value Vi1 becomes the upper limit current value Icm. As the charging of the second battery 12 proceeds, the voltage value across the second battery 12 increases, and the voltage value Vc output from the transformer circuit 20 also increases as the voltage value increases.

  Here, the resistance value of a conductor (not shown) connecting the first end of the DCDC converter 10 and the positive electrode of the second battery 12 is 0.01 ohm, the upper limit current value Icm is 100 amperes, and the upper limit voltage value Vcm is 20 volts. And When the voltage value across the second capacitor 12 is 1 volt, the voltage value Vc output from the transformer circuit 20 is controlled to 2 (= 100 × 0.01 + 1) volts. Thereby, the current value Ic becomes the current value Icm (= 100 amperes). When the charging of the second capacitor 12 proceeds and the voltage value across the second capacitor 12 becomes 2 volts, the voltage value Vc output from the transformer circuit 20 is controlled to 3 (= 100 × 0.01 + 2) volts. Is done. As described above, the voltage value Vc output from the transformer circuit 20 rises to the upper limit voltage value Vcm (= 20 volts) in a state where the current value Ic is maintained at the upper limit current value Icm.

After the voltage value Vc indicated by the voltage value V1 reaches the upper limit voltage value Vcm, the control unit 52 maintains the voltage value Vc output from the transformer circuit 20 at the current value. Thereafter, as the charging of the second battery 12 proceeds, the current value Ic flowing through the resistor R1 gradually decreases. When a stop instruction is input to the input unit 45 in the charging process, the control unit 52 instructs the drive unit 40 in a state where the voltage value Vc at the first end of the DCDC converter 10 is maintained. Stop driving.
Each of the upper limit current value Icm and the upper limit voltage value Vcm is a constant value and is stored in the storage unit 51 in advance.

  The control unit 52 performs a discharge process when a discharge instruction is input to the input unit 45. Even in the discharge process, the control unit 52 instructs the drive unit 40 to drive the transformer circuit 20. The transformer circuit 20 transforms the voltage input via the resistor R1 of the first current detector 22, and outputs the transformed voltage to the first capacitor 11 and the load 14 via the resistor R4 of the current detector 23. As a result, the first battery 11 is charged and the load 14 is supplied with power.

  Further, the control unit 52 controls the voltage value Vb output from the second end of the DCDC converter 10 to the first capacitor 11 and the load 14 through the driving unit 40. In the discharging process, the control unit 52 controls the voltage value Vb similarly to the voltage value Vc in the charging process.

That is, the control unit 52 determines whether the current value Ib indicated by the voltage value Vi2 acquired from the A / D conversion unit 48 becomes the upper limit current value Ibm or the voltage indicated by the voltage value V2 acquired from the A / D conversion unit 49. The voltage value Vb output from the transformer circuit 20 is controlled so that the value Vb becomes the upper limit voltage value Vbm. The current value Ib flowing through the resistor R4 and the voltage value Vb output from the transformer circuit 20 change in the same manner as the current value Ic and voltage value Vc in the charging process (see FIG. 3). When a stop instruction is input to the input unit 45 even in the discharge process, the control unit 52 instructs the drive unit 40 in a state where the voltage value Vb at the second end of the DCDC converter 10 is maintained. Stop driving.
The upper limit current value Ibm and the upper limit voltage value Vbm are both constant values and are stored in advance in the storage unit 51.

  As described above, the control unit 52 executes the first detection process in parallel with the charging process, and executes the second detection process in parallel with the discharge process. The control unit 52 periodically executes the first detection process while the charging process is being executed, and periodically executes the second detection process while the discharge process is being executed. Hereinafter, the first detection process will be described.

  4 and 5 are flowcharts showing the procedure of the first detection process executed by the control unit 52. FIG. Similarly to the charging process, the control unit 52 executes the first detection process when a charging instruction is input. The storage unit 51 stores a counter value, and the counter value is set to zero when a charging instruction is input to the input unit 45.

  First, the control unit 52 acquires the voltage value Vi1 from the A / D conversion unit 46 (step S1), and calculates the current value Ic based on the acquired voltage value Vi1 (step S2). Next, the controller 52 determines whether or not the current value Ic calculated in step S2 exceeds the current threshold Icth (step S3). The current threshold Icth is a constant value and is stored in the storage unit 51 in advance. As shown in FIG. 3, the current threshold Icth exceeds zero ampere and is less than the upper limit current value Icm.

  When determining that the current value Ic exceeds the current threshold value Icth (S3: YES), the control unit 52 acquires the voltage value V1 from the A / D conversion unit 47 (step S4), and obtains the acquired voltage value V1. Based on this, the voltage value Vc is calculated (step S5).

  Next, the controller 52 determines whether or not the voltage value Vc calculated in Step S5 exceeds the voltage threshold value Vcth (Step S6). The voltage threshold value Vcth is a constant value and is stored in the storage unit 51 in advance. As shown in FIG. 3, the voltage threshold Vcth exceeds zero volt and is less than the upper limit voltage value Vcm.

  When it is determined that the voltage value Vc exceeds the voltage threshold value Vcth (S6: YES), the control unit 52 acquires the voltage value Vi2 from the A / D conversion unit 48 (step S7), and obtains the acquired voltage value Vi2. Based on this, the current value Ib is calculated (step S8). Next, the control unit 52 acquires the voltage value V2 from the A / D conversion unit 49 (step S9), and calculates the voltage value Vb based on the acquired voltage value V2 (step S10). Thereafter, the control unit 52 uses the current value Ic, the voltage value Vc, the current value Ib, and the voltage value Vb calculated in steps S2, S5, S8, and S10, respectively, to provide an index value related to the efficiency of the transformation performed by the transformer circuit 20. G is calculated (step S11).

When the input current value, the input voltage value, the output current value, and the output voltage value of the transformer circuit 20 are Iin, Vin, Iout, and Vout, the index value G is expressed by the following equation (1).
G = (Iout− (Iin × Vin / Vout)) / Iout (1)

The efficiency E of the transformation performed by the transformer circuit 20 is (Iout × Vout) / (Iin × Vin), which is a value between zero and 1 inclusive. The index value G is expressed as follows using the efficiency E.
G = (1- (1 / E))
Therefore, the index value G is larger as the efficiency E is higher and is equal to or less than zero. When the loss generated when the transformer circuit 20 performs transformation is zero watts, the power input to the transformer circuit 20 matches the power output from the transformer circuit 20 and the efficiency E is 1. At this time, the index value G is zero.

In the first detection process executed in parallel with the charging process, the output current value Iout, the output voltage value Vout, the input current value Iin, and the input voltage value Vin are the currents calculated in steps S2, S5, S8, and S10. The value Ic, the voltage value Vc, the current value Ib, and the voltage value Vb.
As described above, the control unit 52 calculates the index value G based on the detection results of the current detectors 22 and 23 and the voltage detectors 24 and 25. The control unit 52 functions as a calculation unit.

  Next, the control unit 52 determines whether or not the index value G calculated in step S11 is less than the index threshold Gth (step S12). The index value Gth is a constant value and is stored in the storage unit 51 in advance. The index value Gth is less than zero. The control unit 52 determines whether or not the efficiency E indicated by the index value G calculated in Step S11 is less than a predetermined reference efficiency Er by executing Step S12. When the index value G is greater than or equal to the index threshold Gth, the efficiency E is greater than or equal to the reference efficiency Er, and when the index value G is less than the index threshold Gth, the efficiency E is less than the reference efficiency Er. The reference efficiency Er is 1 / (1-Gth). The control unit 52 also functions as an efficiency determination unit.

  The control unit 52 determines that the current value Ic is equal to or less than the current threshold Icth (S3: NO), determines that the voltage value Vc is equal to or less than the voltage threshold Vcth (S6: NO), or the index value G Is determined to be greater than or equal to the index threshold Gth (S12: NO), the counter value is set to zero (step S13), and the first detection process is terminated. In the case where the charging process is continued, the control unit 52 executes the first detection process again when the next cycle arrives.

When it is determined that the index value G is less than the index threshold Gth (S12: YES), the control unit 52 increments the counter value by 1 (step S14). Next, the control unit 52 determines whether or not the counter value is greater than or equal to the reference value (step S15). The reference value is an integer equal to or greater than 2, and is stored in advance in the storage unit 51.
The counter value is the number of times that the index value G is continuously determined to be less than the index threshold Gth. Step S15 corresponds to a process of determining whether or not it is determined that the index value G is less than the index threshold Gth continuously for the number of times indicated by the reference value.

When it is determined that the counter value is equal to or greater than the reference value (S15: YES), the controller 52 stops the transformation of the transformer circuit 20 by causing the drive unit 40 to stop driving the transformer circuit 20 (step S16). . In this way, the control unit 52 stops the transformation of the transformer circuit 20 when it is determined that the index value G calculated in step S11 is less than the index threshold Gth, that is, the transformation efficiency E is less than the reference efficiency Er. To do. The control unit 52 also functions as a stop unit.
After executing Step S16, the control unit 52 instructs the output unit 50 to output a notification signal to the notification unit 15 (Step S17). Thereby, the abnormality regarding the transformer circuit 20 is notified.

  Thereafter, the controller 52 forcibly ends the charging process (step S18), and sets the counter value to zero (step S19). Thereafter, the control unit 52 ends the first detection process. In this case, the control unit 52 continues to stop the transformation performed by the transformer circuit 20 until the ignition signal input to the input unit 45 indicates that the ignition switch is turned off, and performs the first detection process and the second detection process. Neither is executed. When the charging instruction is input to the input unit 45 after determining that the ignition switch has been switched from OFF to ON based on the ignition signal input to the input unit 45, the control unit 52 converts the voltage into the transformer circuit 20. To execute the first detection process.

  When it is determined that the counter value is less than the reference value (S15: NO), the control unit 52 ends the first detection process. In the case where the charging process is continued, the control unit 52 executes the first detection process again when the next cycle arrives. At this time, the counter value exceeds zero.

  In the first detection process, as shown in FIG. 3, the controller 52 determines that the current value Ic indicated by the voltage value Vi1 exceeds the current threshold value Icth, and the voltage value Vc indicated by the voltage value V1 exceeds the voltage threshold value Vcth. The index value G is calculated during the exceeding period.

  Similar to the discharge process, the control unit 52 executes the second detection process when a discharge instruction is input. When the discharge instruction is input to the input unit 45, the counter value is set to zero. The control unit 52 executes the second detection process in the same manner as the first detection process.

  The storage unit 51 stores a current threshold Ibth and a voltage threshold Vbth corresponding to the current threshold Icth and the voltage threshold Vcth, respectively. The current threshold value Ibth is a constant value exceeding zero ampere and less than the upper limit current value Ibm. The voltage threshold Vbth is a constant value that exceeds zero volt and is less than the upper limit voltage value Vbm.

  In the description of the first detection process, the charging instruction, the charging process, the first detection process, the A / D converters 46, 47, 48, 49, the voltage values Vi1, Vi2, V1, V2, Vc, Vb, Vcth and the current value. Ic, Ib, and Icth are changed to discharge instruction, discharge process, second detection process, A / D converters 48, 49, 46, and 47, voltage values Vi2, Vi1, V2, V1, Vb, Vc, Vbth, and current value, respectively. Replace with Ib, Ic, Ibth. Thereby, the second detection process can be described.

  In the second detection process executed in parallel with the discharge process, the output current value Iout, the output voltage value Vout, the input current value Iin, and the input voltage value Vin are the current value Ib, voltage calculated by the control unit 52, respectively. The value Vb, the current value Ic, and the voltage value Vc.

  The index threshold Gth in the first detection process may be different from the index threshold Gth in the second detection process. In other words, the reference efficiency Er in the first detection process may be different from the reference efficiency Er in the second detection process. Similarly, the reference value in the first detection process may be different from the reference value in the second detection process.

  In the first detection process, the current value Ib, the voltage value Vb, the current value Ic, and the voltage value Vc correspond to the input current value, the input voltage value, the output current value, and the output voltage value of the transformer circuit 20, respectively. Therefore, in the first detection process, the current detector 23, the voltage detector 25, the current detector 22 and the voltage detector 24 are respectively an input current detector, an input voltage detector, an output current detector and an output voltage detector. Function as.

  In the second detection process, the current value Ic, the voltage value Vc, the current value Ib, and the voltage value Vb correspond to the input current value, the input voltage value, the output current value, and the output voltage value of the transformer circuit 20, respectively. Therefore, in the second detection process, the current detector 22, the voltage detector 24, the current detector 23, and the voltage detector 25 are respectively an input current detector, an input voltage detector, an output current detector, and an output voltage detector. Function as.

  In the microcomputer 21 configured as described above, the current value Ic indicated by the voltage value Vi1 detected by the current detector 22 or the voltage value Vc indicated by the voltage value V1 detected by the voltage detector 24 is greater than the actual value. When it is smaller, in the first detection process, the control unit 52 determines that the efficiency E of the transformation indicated by the index value G is less than the reference efficiency Er. Thereby, the control part 52 can detect appropriately that the electric current value Ic or the voltage value Vc which the detection result of the electric current detector 22 or the voltage detector 24 shows is lower than an actual value.

Further, when the current value Ib indicated by the voltage value Vi2 detected by the current detector 23 or the voltage value Vb indicated by the voltage value V2 detected by the voltage detector 25 is smaller than the actual value, The controller 52 determines that the transformation efficiency E indicated by the index value G is less than the reference efficiency Er. Thereby, the control part 52 can detect appropriately that the electric current value Ib or the voltage value Vb which the detection result of the electric current detector 23 or the voltage detector 25 shows is lower than an actual value.
Further, even when the efficiency of the transformation performed by the transformer circuit 20 is small because the drive unit 40 does not drive the transformer circuit 20 properly, the operation of the drive unit 40 is performed in the first detection process or the second detection process. Abnormality is detected.

  In the first detection process, when at least one of the current value Ic indicated by the voltage value Vi1 and the voltage value Vc indicated by the voltage value V1 is small, the actual efficiency of the transformation performed by the transformer circuit 20 is low. In this case, even if the current value Ic indicated by the voltage value Vi1, the voltage value Vc indicated by the voltage value V1, the current value Ib indicated by the voltage value Vi2, and the voltage value Vb indicated by the voltage value V2 are appropriate, the index value G May be less than the index threshold Gth. In the first detection process, the control unit 52 determines the index value when the current value Ic indicated by the voltage value Vi1 exceeds the current threshold value Icth and the voltage value Vc indicated by the voltage value V1 exceeds the voltage threshold value Vcth. G is calculated, and it is determined whether or not the transformation efficiency E indicated by the calculated index value G is less than the reference efficiency Er. For this reason, the probability that erroneous detection is performed is low.

  Similarly, in the second detection process, when at least one of the current value Ib indicated by the voltage value Vi2 and the voltage value Vb indicated by the voltage value V2 is small, the actual efficiency of the transformation performed by the transformer circuit 20 is low. In the second detection process, the controller 52 determines the index value when the current value Ib indicated by the voltage value Vi2 exceeds the current threshold value Ibth and the voltage value Vb indicated by the voltage value V2 exceeds the voltage threshold value Vbth. G is calculated, and it is determined whether or not the transformation efficiency E indicated by the calculated index value G is less than the reference efficiency Er. For this reason, the probability that erroneous detection is performed is low.

  In each of the first detection process and the second detection process, the control unit 52 stops the transformation of the transformer circuit 20 when it is determined that the transformation efficiency E indicated by the calculated index value G is less than the reference efficiency Er. . For this reason, in the first detection process, a difference that occurs between the current value Ic indicated by the voltage value Vi1 and the actual value, or a difference that occurs between the voltage value Vc indicated by the voltage value V1 and the actual value. Thus, an excessive voltage is not continuously output from the transformer circuit 20 to the second battery 12. In the second detection process, the difference between the current value Ib indicated by the voltage value Vi2 and the actual value or the difference generated between the voltage value Vb indicated by the voltage value V2 and the actual value is changed. An excessive voltage is not continuously output from the circuit 20 to the first battery 11 and the load 14.

  Further, the control unit 52 repeatedly executes the first detection process or the second detection process when the counter value is less than the reference value while the charge process or the discharge process is being performed. Therefore, the control unit 52 repeatedly calculates the index value G, and determines whether the efficiency E is less than the reference efficiency Er each time the index value G is calculated. When the controller 52 determines that the efficiency E of the transformation indicated by the calculated index value G is less than the reference efficiency Er, more specifically, when the controller 52 continuously determines the number of times indicated by the reference value, the transformer circuit Stop 20 transformations. For this reason, the control part 52 can stop the transformation of the transformation circuit 20 when the probability that the abnormality regarding the transformation circuit 20 has occurred is high.

  In addition, the control part 52 does not need to stop a transformation | transformation, when the efficiency E of the transformation | transformation which the calculated index value G shows is less than the reference | standard efficiency Er, when it determines continuously by the frequency | count which a reference | standard value shows. For example, when the controller 52 determines that the efficiency E of the transformation indicated by the calculated index value G is less than the reference efficiency Er, the control unit 52 may stop the transformation. Even in this case, the controller 52 determines that at least one of the current values Ic and Id and the voltage values Vc and Vd indicated by the detection results of the current detectors 22 and 23 and the voltage detectors 24 and 25 is greater than the actual value. It can be properly detected that the value is low.

Further, the formula for calculating the index value G is not limited to the formula (1), and any formula that calculates a value according to the efficiency E may be used. When the index value G is larger as the efficiency E is smaller, the control unit 52 determines that the efficiency E is less than the reference efficiency Er when the index value G exceeds the index threshold Gth, and the index value G is equal to or less than the index threshold Gth. It is determined that the efficiency E is equal to or higher than the reference efficiency Er.
Further, the control unit 52 may directly calculate the efficiency E of the transformation performed by the transformer circuit 20 and determine whether the calculated efficiency E is less than the reference efficiency Er.

  The disclosed embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Power supply system 10 DCDC converter (transformer)
12 Second capacitor 20 Transformer circuit 21 Microcomputer (semiconductor device)
22, 23 Current detector (input current detector, output current detector)
24,25 Voltage detector (input voltage detector, output voltage detector)
52 Control unit (calculation unit, efficiency determination unit, stop unit)

Claims (7)

In a semiconductor device that detects an abnormality related to a transformer circuit that transforms an input voltage and outputs the transformed voltage,
An input current detector for detecting a value related to the input current value of the transformer circuit, an input voltage detector for detecting a value related to the input voltage value of the transformer circuit, and an output for detecting a value related to the output current value of the transformer circuit Based on the detection result of the current detector and the output voltage detector that detects the value related to the output voltage value of the transformer circuit, a calculation unit that calculates an index value related to the efficiency of the transformation performed by the transformer circuit;
An efficiency determination unit that determines whether or not the efficiency indicated by the index value calculated by the calculation unit is less than a predetermined efficiency. The input current value, the input voltage value, the output current value, and the output voltage value indicated by the detection results of the input current detector, the input voltage detector, the output current detector, and the output voltage detector are represented by Iin, Vin, Iout, and Vout, respectively. 2. The semiconductor device according to claim 1, wherein the index value is (Iout− (Iin × Vin / Vout)) / Iout. When it is determined that the output current value indicated by the detection result of the output current detector exceeds the current threshold, the calculation unit calculates the index value, and the efficiency determination unit performs determination. The semiconductor device according to claim 1 or 2. 4. The apparatus according to claim 1, further comprising a stop unit that stops the transformation of the transformer circuit when the efficiency judging unit judges that the efficiency is less than the predetermined efficiency. Semiconductor device. The calculation unit repeatedly calculates the index value,
The efficiency determination unit determines whether the efficiency is less than the predetermined efficiency each time the calculation unit calculates the index value.
The semiconductor device according to claim 4, wherein the stopping unit stops the transformation of the transformer circuit when the efficiency determining unit continuously determines that the efficiency is less than the predetermined efficiency a plurality of times. apparatus. A semiconductor device according to any one of claims 1 to 5;
A transformer apparatus comprising: the transformer circuit, an input voltage detector, an input current detector, an output voltage detector, and an output current detector. A transformer device according to claim 6;
And a capacitor to which the voltage output from the transformer circuit is applied.

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