JP2007166856A - Control device of power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably operate a load in a range such that the output from a DC power supply will not become excessive, in a power supply system that supplies power to the load from the DC power supply. <P>SOLUTION: An excessive output condition detecting part 110 generates an output condition flag FLG, which shows whether a DC power supply is in an excessive output condition or in a normal output condition, based on the output voltage Vb or the output current Ib of the DC power supply. A torque command value generating part 120, according to the output condition flag FLG, sets a torque command value Tqcom of a motor generator 50 to be a value Tqcom#, which is in accordance with the load output requirement, if the DC power supply is in normal output condition; whereas the part generates a torque command value Tqcom, limited to the range where the excessive output condition will not generate intermittently, if the DC power supply is in the excessive output condition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a power supply system, and more particularly to a control device for a power supply system that supplies power from a DC power supply to a load.

  A general DC power source represented by a secondary battery has an internal resistance. Therefore, in such a power supply system that supplies power to the load from the DC power supply, the output from the DC power supply becomes excessive and the output fluctuates in consideration of the output characteristics of the DC power supply (secondary battery), particularly the internal resistance. It is necessary to operate the load in such a range that it does not.

  For example, Japanese Patent Laid-Open No. 2000-19233 (Patent Document 1) discloses a battery configured to divide a battery output range into a plurality of regions and calculate a maximum output of the battery from voltage-current characteristics measured for each region. An output detection apparatus is disclosed. In particular, Patent Document 1 discloses that the maximum output of the main battery of a hybrid vehicle can be accurately calculated for each output region by such a battery output detection device.

Japanese Patent Application Laid-Open No. 7-193903 (Patent Document 2) discloses a control device for an electric vehicle that prevents deterioration in driving feeling due to an abnormal drop in voltage of a main battery (main battery). In the configuration disclosed in Patent Document 2, the power running torque of the induction motor is suppressed when the voltage of the main battery is lower than the reference voltage set to be equal to or higher than the minimum operating voltage of the inverter control device that drives and controls the induction motor. The inverter is controlled to do so.
JP 2000-19233 A Japanese Patent Laid-Open No. 7-193903

  In the power supply system as described above, when the power corresponding to the output required for the load (hereinafter referred to as the load request output) is taken out from the battery, generally, the power in the expected load output range is supplied. The DC power supply is designed as possible. However, depending on the state of the DC power supply, for example, when the internal resistance of the secondary battery increases due to a decrease in temperature, it may be possible that power corresponding to the load request output cannot be output from the DC power supply.

  In such a case, if the power supply system is operated so that power corresponding to the load required output is simply supplied to the load, the power consumed by the internal resistance of the DC power supply increases, and the output voltage of the DC voltage is increased. May be reduced. In particular, if a smoothing capacitor is provided between the DC power supply and the battery, the voltage of the smoothing capacitor having a low impedance may drop rapidly, which may cause a problem in the operation of the load.

  The present invention has been made to solve such problems, and an object of the present invention is a range in which the output from the DC power supply does not become excessive in a power supply system that supplies power from the DC power supply to the load. It is an object of the present invention to provide a control device for a power supply system capable of stably operating a load.

  A power supply system control apparatus according to the present invention is a power supply system control apparatus that supplies power from a DC power supply to a load, and includes an operation command setting means, a detection means, and an output restriction means. The operation command setting means sets the operation command value of the load according to the output request to the load. The detecting means detects an excessive output state when the output of the DC power source exceeds the normal range set based on the output characteristics of the DC power source. The output limiting means limits the operation command value so that the excessive output state of the DC power supply does not continue when the excessive output state is detected by the detection means.

  According to the control device of the power supply system, it is possible to prevent the load operation command value from being continuously generated in a range in which the DC power supply is in an excessive output state when the DC power supply is in an excessive output state. . Accordingly, it is possible to prevent a phenomenon in which the output voltage of the direct-current power supply is suddenly lowered and trouble occurs in the operation of the load due to the load continuously operating in an excessive output state. That is, the load can be stably operated within a range where the output from the DC power supply does not become excessive.

  Preferably, the control device of the power supply system according to the present invention includes a voltage detector that detects an output voltage of the DC power supply. Further, the detecting means detects an excessive output state when the output voltage detected by the voltage detector is equal to or lower than a determination voltage set based on the open voltage of the DC power supply.

  According to the control device of the power supply system, it is possible to accurately detect the occurrence of the excessive output state based on the detected value of the output voltage of the DC power supply.

  More preferably, in the control device of the power supply system according to the present invention, the determination voltage is set in the vicinity of ½ of the open circuit voltage.

  According to the control device of the power supply system, it is possible to appropriately set the determination voltage for detecting an excessive output state according to the output characteristics of the DC power supply.

  Preferably, the control device of the power supply system according to the present invention includes a current detector that detects an output current of the DC power supply. Further, the detecting means detects an excessive output state when the output current detected by the current detector becomes equal to or greater than a determination current set based on the open voltage and internal resistance of the DC power supply.

  According to the control device of the power supply system, it is possible to accurately detect an output excessive state based on the detected value of the output current of the DC power supply.

  More preferably, in the control device for a power supply system according to the present invention, the determination current is set in the vicinity of (Vbo / 2Rb) where the open circuit voltage is Vbo and the internal resistance is Rb.

  According to the control device of the power supply system, it is possible to appropriately set the determination current for detecting the output excessive state according to the output characteristics of the DC power supply.

  Alternatively, preferably, in the control device for a power supply system according to the present invention, the output restriction means includes an upper limit storage means and an operation command value generation means. The upper limit storage means stores the operation command value at that time when transitioning from the normal state to the excessive output state. The operation command value generation means generates a load operation command value with the operation command value stored in the storage means as the upper limit value during the continuation of the output excessive state after the transition.

  According to the control device of the power supply system, it is possible to limit the load operation command value within the range having the upper limit of the load operation command value at the time of transition to the excessive output state. Therefore, it is possible to more reliably prevent the load operation command value from being continuously generated within a range in which the DC power supply is in an excessive output state.

  Preferably, in the control device for a power supply system according to the present invention, the DC power supply supplies power to a plurality of loads, and the output restriction means includes an upper limit storage means and an operation command value generation means. The upper limit storage means stores the output power from the DC power supply for all of the plurality of loads at that time as the maximum power at the transition from the normal state to the excessive output state. The operation command value generation means generates operation command values for a plurality of loads within the range of the maximum power stored in the upper limit storage means during the continued output overload after the transition.

  According to the control device for a power supply system described above, in a configuration in which a DC power supply is supplied by a plurality of loads, the load operation command is within a range in which the output power from the DC power supply does not exceed the value at the time of transition to an output excessive state Can be limited to values. Therefore, it is possible to more reliably prevent the operation command values for a plurality of loads from being continuously generated within a range in which the DC power supply is in an excessive output state.

  According to the control device for a power supply system according to the present invention, in a power supply system that supplies power from a DC power supply to a load, the load can be stably operated within a range in which the output from the DC power supply does not become excessive.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

  FIG. 1 is a block diagram illustrating a configuration of a power supply system 5 according to the embodiment of the present invention.

  Referring to FIG. 1, power supply system 5 according to the embodiment of the present invention includes a DC power supply 10, a smoothing capacitor 20, and a load 30. Further, as a control device of the power supply system 5, an electronic control unit (ECU) 100 and a host ECU 90 that gives an operation command value corresponding to a load output request to the ECU 100 are provided. Note that the host ECU 90 and the ECU 100 can be configured by a single ECU.

  The DC power supply 10 is typically composed of a secondary battery such as a lithium ion battery or a nickel metal hydride battery. As the DC power source 10, a large-capacity power storage device such as an electric double layer capacitor or a fuel cell can be applied.

  The DC power supply 10 is provided with a voltage sensor 60 for measuring an output voltage (hereinafter also referred to as battery voltage Vb) and a current sensor 65 for detecting an input / output current (hereinafter also referred to as battery current Ib). When the electromotive force (open voltage) Vbo of the DC power supply 10 and the internal resistance are Rb, the following expression (1) is established as the output characteristics of the DC power supply 10.

Vb = Vbo−Ib · Rb (1)
It is assumed that the state of charge (SOC) of DC power supply 10 is separately managed based on the integrated value of battery current Ib detected by current sensor 65, for example. Alternatively, a dynamic model formula that determines the internal state of the DC power supply 10 is separately created, and sequentially based on the above-described battery voltage Vb, battery current Ib, and battery state quantity such as battery temperature measured by a temperature sensor (not shown). The open circuit voltage Vbo and the charging rate (SOC) may be obtained online.

  The open circuit voltage Vbo in the equation (1) may be a rated value (a constant value) within the normal range of the charging rate (SOC), or may be calculated according to the charging rate (SOC). In particular, it is known that in a lithium ion secondary battery, there is a high correlation between the charging rate (SOC) and the open circuit voltage Vbo. Or it is good also as a control structure which measures the battery voltage Vb at the time of a stop of load (namely, battery current Ib = 0 time), and memorize | stores the measured value at this time as the open circuit voltage Vbo timely.

  Smoothing capacitor 20 is provided between DC power supply 10 and load 30 and smoothes a DC voltage exchanged between them.

  The load 30 includes, for example, an inverter 40 and an electric motor 50 that is driven and controlled by the inverter 40. The electric motor 50 may be configured by a motor generator that can perform both a power running operation and a regenerative braking operation, that is, can operate as both an electric motor and a generator. As such a motor generator, for example, a three-phase synchronous motor including a stator (not shown) provided with a three-phase coil winding and a rotor (not shown) is used. Hereinafter, the electric motor 50 is referred to as a motor generator 50.

  For example, the motor generator 50 is mounted on an electric vehicle such as a hybrid vehicle, and is rotated by power supplied from the DC power source 10 during powering operation to generate a vehicle driving force and with the deceleration of the electric vehicle. To generate regenerative braking power.

  Note that regenerative braking here refers to braking that involves regenerative power generation when the driver operating the hybrid vehicle performs a footbrake operation, or regenerative braking by turning off the accelerator pedal while the vehicle is running, although the footbrake is not operated. This includes decelerating (or stopping acceleration) the vehicle while generating electricity.

  The inverter 40 is a general three-phase structure including a power semiconductor switching element (not shown) such as an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, or a power bipolar transistor. Since it is an inverter, detailed description of the configuration is omitted.

  The inverter 40 converts the DC voltage Vb from the DC power supply 10 into a three-phase AC voltage by on / off control (switching control) of a power semiconductor switching element (not shown) in response to the switching control signal SCinv from the ECU 100, The converted three-phase AC voltage can be output to motor generator 50. Thereby, the motor generator 50 is drive-controlled so as to generate an output according to an operation command value typified by a torque command value.

  In addition, during regenerative braking operation of motor generator 50, inverter 40 can convert the three-phase AC voltage generated by motor generator 50 into a DC voltage for charging DC power supply 10 by switching control according to switching control signal SCinv. it can. Thus, inverter 40 performs bidirectional power conversion between DC power supply 10 and load 30.

  The motor generator 50 includes a current sensor 45 for detecting a motor current MCRT (which collectively represents three-phase currents Iu, Iv, and Iw) and a rotational position for detecting a motor rotation angle (electrical angle) θ. A sensor 55 is provided. Current sensor 45 is also received by at least two phases of the three-phase wiring from inverter 40 to motor generator 50. Since the sum of the instantaneous values of the three-phase currents is 0, the motor current of each phase can be detected by detecting the motor current for two phases. Further, the rotation speed Nm of the motor generator 50 can be detected from the motor rotation angle θ detected by the rotation position sensor 55. Motor current MCRT and motor rotation angle θ are input to ECU 100.

  The ECU 100 is configured as a microprocessor centered on a CPU (Central Processing Unit) 102, and includes a ROM (Read Only Memory) 104 that stores processing programs and map data, and a RAM (Random Access) that temporarily stores data. Memory) 106 and an input / output port (not shown). As shown in the figure, the battery voltage Vb and the battery current Ib detected by the voltage sensor 60 and the current sensor 65, and the motor current MCRT and the motor rotation angle θ from the current sensor 45 and the rotational position sensor 55 are input to the ECU 100. Is done.

  The host ECU 90 generates a torque command value Tqcom # as an operation command value of the motor generator 50 in response to the load output request in response to the load output request to the motor generator 50. For example, in an electric vehicle such as a hybrid vehicle, the load output request to the motor generator 50 is determined based on the vehicle running condition, the accelerator opening, and the like. Torque command value Tqcom # generated by host ECU 90 is input to ECU 100.

  Next, the control of the motor generator 50 by the ECU 100 will be described in detail with reference to FIG.

  Referring to FIG. 2, motor control block 101 realized by program processing by ECU 100 includes an output excessive state detection unit 110, a torque command value generation unit 120, and a motor generator control unit (MG control unit) 130.

  Based on the battery voltage Vb or the battery current Ib, the output excessive state detection unit 110 detects whether or not the output from the DC power supply 10 has reached an output excessive range exceeding a predetermined normal range. The output excessive state detection unit 110 sets the output state flag FLG = 0 when the output of the DC power supply 10 is within the normal range (in the normal output state), while the output of the DC power supply 10 is excessive. If it is within the range (when the output is excessive), the output state flag FLG = 1 is set.

  Torque command value generation unit 120 generates final torque command value Tqcom of motor generator 50 in accordance with torque command value Tqcom # from host ECU 90 and output state flag FLG from output excessive state detection unit 110. Torque command value Tqcom generated by torque command value generation unit 120 is provided to motor generator control unit (MG control unit) 130.

  Based on the motor current MCRT and the motor rotation angle θ detected by the current sensor 45, the MG control unit 130 typically performs feedback control of the motor current MCRT and torque feedback control using a torque estimation value based on the motor state quantity. The operation of the inverter 40 is controlled. Specifically, MG control unit 130 outputs switching control signal SCinv so that AC power that causes motor generator 50 to generate output torque according to torque command value Tqcom is supplied from inverter 40 to motor generator 50. Generate. In other words, when the inverter 40 performs DC-AC (AC-DC) power conversion according to the switching control signal SCinv, a motor current for generating an output torque according to the torque command value Tqcom is generated from the inverter 40 to the motor generator. 50.

Next, the output characteristics of the DC power supply 10 will be described with reference to FIG.
The output power Pout from the DC power supply 10 is expressed by the following equation (2).

Pout = Vb · Ib (2)
Substituting the above expression (1) into the above expression (2) yields the following expression (3).

As shown in the equation (3) and FIG. 3, the output power Pout is expressed by a quadratic function of the battery current Ib. When the battery current Ib = (Vbo / 2Rb), the maximum value Pout = (Vbo ² / 4Rb ² ).

  Further, the battery voltage Vb is expressed by a linear function of the battery current Ib as shown in the equation (1) and FIG. 3, and decreases as the battery current Ib increases due to an increase in voltage drop at the internal resistance Rb. I will do it. In particular, when the battery current Ib = (Vbo / 2Rb) at which the output power Pout is maximum, the battery voltage Vb = Vbo / 2.

  In the embodiment of the present invention, basically, the normal output range of the DC power supply 10 is in the range of 0 ≦ Ib ≦ (Vbo / 2Rb), and the range of the battery current Ib> (Vbo / 2Rb) is defined as the output excessive range. To do. As described above, the normal range and the excessive output range are determined based on the output characteristics of the DC power supply 10.

  Normally, DC power supply 10 is designed so that the output request (load output request) of motor generator 50 can be covered by the output within the normal range in consideration of the normal output request to motor generator 50.

  However, when the internal resistance Rb increases or during special operation of the motor generator 50 (for example, when a wheel slip occurs in an electric vehicle equipped with the motor generator 50), the operation command value (typically, the motor generator 50). (Torque command value) may be generated in a region corresponding to an excessive output range exceeding the normal range.

  Therefore, in the control device for the power supply system according to the present embodiment, the following description will be made so that the operation command for the load (motor generator 50) is not continuously generated in the region corresponding to the output excessive range of DC power supply 10. Executes the setting control of the correct operation command value. In the present embodiment, setting control of a torque command value (Tqcom) of motor generator 50 will be described as load operation command value setting control.

  FIG. 4 is a flowchart showing an example of a load operation command value setting routine according to the embodiment of the present invention. This routine is repeatedly executed by the ECU 100 every predetermined time (for example, every 0.2 msac).

  Referring to FIG. 4, ECU 100 obtains torque command value Tqcom # from host ECU 90 in accordance with the load output request in step S100. Furthermore, ECU 100 acquires battery voltage Vb from the output of voltage sensor 60 in step S110. At this time, the open circuit voltage Vbo is also acquired as a design value or an estimated value from the current battery state (SOC or the like).

  Further, ECU 100 determines in step S120 whether or not DC power supply 10 is in an excessive output state. In step S120, the determination is performed by comparing the battery voltage Vb acquired in step S110 with the determination voltage Vjd. Here, the determination voltage Vjd is set in the vicinity of (Vbo / 2) as understood from FIG.

  When Vb> Vjd (NO in step S120), ECU 100 sets output state flag FLG = 0 in step S130 because DC power supply 10 is in the normal output state. On the other hand, when Vb ≦ Vjd (when YES is determined in step S120), ECU 100 sets output state flag FLG = 1 in step S150 because DC power supply 10 is in an excessive output state.

  As described above, the processing in steps S120, S130, and S150 corresponds to the operation by the output excessive state detection unit 110 in FIG.

  In the normal output state where the output state flag FLG = 0 is set, the ECU 100 generates an operation command value according to the load output request in step S140. That is, the final torque command value Tqcom = Tqcom # of motor generator 50 is set.

  On the other hand, when the output state flag FLG = 1 is set and the output is excessive, the ECU 100 sets the operation command value (torque command value) to prevent the excessive output state of the DC power supply 10 from continuing in steps S150 and S160. Add restrictions.

  In step S160, ECU 100 determines whether or not a transition from the normal output state to the excessive output state has occurred in the current torque command value setting routine, based on output state flag FLG. When YES is determined in step S160, that is, at the time of transition from the normal output state to the excessive output state, the current torque command value Tqcom, that is, the torque command value Tqcom in the previous normal output state is stored as the torque command upper limit value Tqmax. .

  On the other hand, when NO is determined in step S160, that is, when the output is continuously excessive, step S170 is not executed and the torque command upper limit value Tqmax is not updated.

  Further, ECU 100 does not generate an operation command value (torque command value) as requested by the load output when the output of DC power supply 10 is excessive in step S180, but in the range of torque command upper limit value Tqmax set in step S170. And a torque command value Tqcom is generated.

  As described above, the processing in steps S140 and S160 to S180 corresponds to the operation by the torque command value generation unit 120 in FIG.

  Thus, according to the power supply system control apparatus of the present embodiment, torque command value Tqcom (that is, load operation command) of motor generator 50 is continuously within a range in which DC power supply 10 is in an excessive output state. It is possible to realize load operation command value setting control that can be prevented from being generated.

  As a result, the DC power supply 10 can be used within the assumed normal output range, so that the load can be controlled as instructed and the stability of the load control is improved. On the other hand, if the DC power supply 10 is operated in an excessive output state, it becomes difficult for the load (motor generator 50) to control as commanded due to a decrease in the output voltage or the like. In particular, when such a phenomenon occurs in the motor generator 50 mounted on an electric vehicle, vibrations, surges, etc. may occur and the vehicle behavior may become unstable. However, the motor generator 50 according to the present invention may be unstable. Such a problem can be reliably avoided by the torque command value setting control.

  Moreover, since the load can be reliably operated within the normal output range of the DC power supply 10, the possibility that the voltage of the smoothing capacitor 20 (FIG. 1) changes suddenly can be reduced. As a result, the capacity of the smoothing capacitor can also be reduced, and the size and cost of the device can be reduced.

  Whether the DC power supply 10 is in an excessive output state (step S120 in FIG. 4) can also be executed based on the battery current Ib detected by the current sensor 65, as shown in FIG. .

  Referring to FIG. 5, in another example of the load operation command value setting routine according to the embodiment of the present invention, steps S110 #, S120 are replaced with steps S110, S120 as compared with the flowchart shown in FIG. S120 # is executed.

  ECU 100 obtains battery current Ib from the output of current sensor 65 in step S110 # following step S100 similar to FIG. At this time, the open circuit voltage Vbo and the internal resistance Rb are also acquired as design values or estimated values from the current battery state (SOC or the like).

  In step S120 #, ECU 100 determines whether DC power supply 10 is in an excessive output state by comparing battery current Ib acquired in step S110 # with determination current Ijd. Here, the determination current Ijd is set in the vicinity of (Vbo / 2Rb) as understood from FIG.

  In step S120 #, as in the flowchart shown in FIG. 4, it is determined whether DC power supply 10 is in a normal output state or an excessive output state at that time. Subsequent processing according to this determination is the same as in FIG. 4, and therefore detailed description will not be repeated.

  In this way, even when the battery current Ib detected by the current sensor 65 is used, the load operation command value setting control similar to the above can be realized.

  Here, in the embodiment of the present invention, step S140 in FIGS. 4 and 5 corresponds to the “operation command setting means” in the present invention, and step S120 or S120 # corresponds to the “detection means” in the present invention. Steps S170 and S180 correspond to “output limiting means” in the present invention. In particular, step S170 corresponds to the “upper limit storage unit” of the present invention, and step S180 corresponds to the “operation command generation unit” of the present invention.

[Modification of Embodiment]
FIG. 6 is a block diagram illustrating a configuration of a power supply system 5 # according to a modification of the embodiment of the present invention.

  Referring to FIG. 6, power supply system 5 # according to the modification of the embodiment has a configuration in which electric motor 51 and generator 52 are driven by common DC power supply 10. That is, in power supply system 5 #, load 30 # is used instead of load 30 in FIG. Load 30 # includes an electric motor 51 and an electric generator 52 as a plurality of loads, and inverters 41 and 42 for driving and controlling electric motor 51 and electric generator 52.

  Typically, load 30 # is mounted on a hybrid vehicle. At this time, the electric motor 51 operates in the same manner as the motor generator 50 in the power supply system shown in FIG. That is, the electric motor 51 is rotationally driven by the electric power from the DC power source 10, and the output becomes the driving force of the driving wheels (not shown). Further, the electric motor 51 acts as a generator during a regenerative braking operation that is rotated as the drive wheels are decelerated.

  The generator 52 is configured to be able to generate power by being rotated by a driving force from an engine (not shown). Further, the generator 52 may be configured to start the engine by operating as an electric motor for the engine by the electric power from the DC power supply 10. In such a configuration, a power split mechanism (not shown) is provided, and the driving force generated by the engine can be divided into a path to the drive wheels and a path to the generator 52. As described above, each of the electric motor 51 and the electric generator 52 can typically be constituted by a three-phase synchronous electric motor similar to the motor generator 50.

  The inverter 41 drives and controls the electric motor 51, and the inverter 42 drives and controls the generator 52. Since each of inverters 41 and 42 is a general three-phase inverter composed of a power semiconductor switching element (not shown), detailed description of the configuration is omitted.

  Inverter 41 converts DC voltage Vb from DC power supply 10 into a three-phase AC voltage by switching control of the power semiconductor switching element in response to switching control signal SCinv1 from ECU 100 #, and converts the converted three-phase AC voltage. It can be output to the electric motor 51. Thereby, electric motor 51 is drive-controlled so as to generate an output torque according to the torque command value (Tqcom1).

  Further, the inverter 41 converts the three-phase AC voltage generated by the electric motor 51 by receiving the rotational force from the drive wheels into a DC voltage by switching control according to the switching control signal SCinv1 during regenerative braking of the hybrid vehicle.

  Inverter 42 can generate output torque according to torque command value (Tqcom2) by generator 52 by switching control in response to switching control signal SCinv2 from ECU 100 #. Further, when the generator 52 is driven by the engine to generate power, the inverter 42 converts the three-phase AC voltage generated by the generator 52 into a DC voltage by switching control in response to the switching control signal SCinv2. In this manner, the inverters 41 and 42 perform bidirectional power conversion between the DC power supply 10, the motor 51, and the generator 52.

  ECU 100 # is a torque command value Tqcom1 # for each of motor 51 and generator 52 in accordance with an operation request (load output request) to motor 51 and generator 52 based on the vehicle status of the hybrid vehicle, the accelerator opening, and the like. , Tqcom2 #. Torque command values Tqcom1 # and Tqcom2 # are shown as representative load operation command values.

  Further, ECU 100 # generates switching control signal SCinv1 of inverter 41 and switching control signal SCinv2 of inverter 42 so as to control the outputs of electric motor 51 and generator 52 in accordance with the operation command. Similar to ECU 100 in power supply system 5 shown in FIG. 1, ECU 100 # operates the load so as to limit the operation command values (torque command values) of motor 51 and generator 52 when the output of DC power supply 10 is excessive. Execute command value setting control. Here as well, setting control of torque command values (Tqcom1, Tqcom2) of the electric motor 51 and the generator 52 will be described as load operation command value setting control.

  Referring to FIG. 7, motor control block 101 # realized by program processing by ECU 100 # includes an output excessive state detection unit 110 and a torque command value generation unit 120 #. The output excessive state detection unit 110 has the same function as the output excessive state detection unit shown in FIG.

  Torque command value generation unit 120 # receives torque command value Tqcom1 of motor 51 and generator 52 according to torque command values Tqcom1 #, Tqcom2 # and output state flag FLG according to a load output request from the host ECU (FIG. 1). Torque command value Tqcom2 is generated. Control of each of motor 51 and generator 52 in accordance with torque command values Tqcom1 and Tqcom2 is the same as the operation after MG control unit 130 shown in FIG. 2, and therefore detailed description will not be repeated.

  Next, a setting routine for torque command values Tqcom1 and Tqcom2 of the electric motor 51 and the generator 52 according to the functional block diagram shown in FIG. 7 will be described with reference to FIG. This routine is repeatedly executed by the ECU 100 every predetermined time (for example, every 0.2 msac).

  Referring to FIG. 8, in the operation command value setting routine for the load according to the modification of the embodiment of the present invention, ECU 100 # performs steps S100, S110 (or S110) similarly to the flowcharts shown in FIGS. #) And S120 (or S120 #) to obtain torque command values Tqcom1 # and Tqcom2 # according to the load output request, and whether the DC power supply 10 is in a normal output state or an output excessive state judge.

  When the DC power supply 10 is in the normal output state (when NO is determined in step S120 or S120 #), steps S130 and S140 are executed, and torque command values for the motor 51 and the generator 52 are generated as requested by the load output. Is done. That is, Tqcom1 = Tqcom1 # and Tqcom2 = Tqcom2 # are set.

  On the other hand, when DC power supply 10 is in an excessive output state (when YES is determined in step S120 or S120 #), steps S150 and S160 similar to those in FIGS. 4 and 5 are first executed.

  When YES is determined in step S160, ECU 100 # calculates power balance Pmg, which is output power from DC power supply 10 to motor 51 and generator 52 as a whole, in step S170 #. That is, the power balance Pmg is given as the sum of the power consumption (or regenerative power generation) in the electric motor 51 and the power generation (or power consumption) generated by the generator 52. For example, the power consumption P = Tqcom / ω (P> 0: power consumption, P <0: power generation) in each of the motor 51 and the generator 52 can be obtained from the torque command value Tqcom and the angular velocity ω. Then, power balance Pmg at the time of transition from the normal output state to the excessive output state is stored as power balance upper limit value Pmax in step S170 #.

  In step S180 #, the ECU 100 # determines that the electric motor 51, the motor 51, within the range of the power balance upper limit value Pmax stored in step S170 #, that is, the range where the output of the DC power supply 10 does not increase with respect to the power balance upper limit value Pmax. Torque command values Tqcom1 and Tqcom2 for the generator 52 are generated.

  By adopting such a control structure, when the DC power supply 10 changes from the normal output state to the excessive output state, the load (the motor 51 and the generator is within a range in which the output from the DC power supply 10 does not increase from that point. 52) can be operated. Thus, similar to the power supply system shown in the embodiment, the DC power supply 10 can be used within the assumed normal output range, so that the load can be controlled as instructed and the load control can be performed. Stability is improved.

  Here, in the modification of the embodiment of the present invention, steps S170 # and S180 # in FIG. 8 correspond to the “output limiting means” in the present invention, and in particular, step S170 # is the “upper limit storage means in the present invention. Step S180 # corresponds to “operation command generation means” of the present invention.

  It should be noted that the configuration of the load in the power supply system shown in the embodiment and its modification is not limited, and if it is an electric system having a load that is driven and controlled according to an operation command, the type and number of the load However, it is possible to perform load operation command value setting control according to the present invention.

  The embodiment disclosed this time 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.

It is a block diagram explaining the structure of the power supply system according to embodiment of this invention. FIG. 2 is a block diagram for explaining in more detail the control of the motor generator by the ECU shown in FIG. 1. It is a figure explaining the output characteristic of the DC power supply shown in FIG. It is a flowchart which shows an example of the operation command value setting routine of the load according to embodiment of this invention. It is a flowchart which shows the other example of the operation command value setting routine of the load according to embodiment of this invention. It is a block diagram explaining the structure of the power supply system according to the modification of embodiment of this invention. It is a functional block diagram regarding the torque command value setting control by ECU shown in FIG. It is a flowchart which shows an example of the operation command value setting routine of the load according to the modification of embodiment of this invention.

Explanation of symbols

  5, 5 # power supply system, 10 DC power supply, 20 smoothing capacitor, 30, 30 # load, 40, 41, 42 inverter, 45 current sensor, 50, 51 electric motor (motor generator), 52 generator, 55 rotational position sensor, 60 voltage sensor, 65 current sensor, 101, 101 # motor control block, 110 output excessive state detection unit, 120 torque command value generation unit, 130 MG control unit, FLG output state flag, Ib battery current, Ijd determination current, MCRT motor Current, Pmax power balance upper limit value, Pmg power balance, Pout output power, Rb internal resistance, SCinv, SCinv1, SCinv2 switching control signal, Tqcom #, Tqcom1 #, Tqcom2 # Torque command value (load output requirement), Tqcom, qcom1, Tqcom2 torque command value (final), Tqmax torque command limit, Vb battery voltage, Vbo open voltage, Vjd determination voltage, theta motor rotational angle.

Claims (7)

A control device for a power supply system that supplies power from a DC power supply to a load,
An operation command setting means for setting an operation command value of the load according to an output request to the load;
Detecting means for detecting an output excessive state when the output of the DC power supply exceeds a normal range set based on the output characteristics of the DC power supply;
A control device for a power supply system, comprising: an output restricting means for restricting the operation command value so that the excessive output state of the DC power supply does not continue when the excessive output state is detected by the detection means. The power supply system includes a voltage detector that detects an output voltage of the DC power supply,
The said detection means detects the said output excessive state, when the said output voltage detected by the said voltage detector becomes below the determination voltage set based on the open circuit voltage of the said DC power supply. The control apparatus of the power supply system of description.   The control device for a power supply system according to claim 2, wherein the determination voltage is set in the vicinity of ½ of the open circuit voltage. The power supply system includes a current detector that detects an output current of the DC power supply,
The detection means detects the excessive output state when the output current detected by the current detector is equal to or higher than a determination current set based on an open voltage and an internal resistance of the DC power supply. The control device of the power supply system according to claim 1.   5. The control device for a power supply system according to claim 4, wherein the determination current is set in the vicinity of (Vbo / 2Rb) where the open-circuit voltage is Vbo and the internal resistance is Rb. The output limiting means is
Upper limit storage means for storing the operation command value at that time at the time of transition from the normal state to the output excessive state;
An operation command value generating means for generating an operation command value of the load with the operation command value stored in the upper limit storage means as an upper limit value during the continuation of the output excessive state after the transition time, The control device of the power supply system according to claim 1. The DC power supply supplies power to the plurality of loads,
The output limiting means is
Upper limit storage means for storing, as maximum power, output power from the DC power supply for all of the plurality of loads at the time of transition from a normal state to the output excessive state;
An operation command value generating means for generating operation command values for the plurality of loads within the range of the maximum power stored in the upper limit storage means during the output excessive state after the transition time; The control apparatus for the power supply system according to claim 1, comprising:

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