JPH10191503A - Control device of hybrid automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a hybrid automobile that can perform retract driving, does not apply load to a capacitor for smoothing of an inverter, and is strong against the control disturbance such as curbstone stranding and slip. SOLUTION: When the trouble of a main battery 12 is detected, an SMR 24 is turned off for shifting to a retract driving, at the same time transistors Q7 -Q12 of an inverter 20 are turned off and the DC output of the inverter 20 is allowed to follow the output fluctuation of a motor 10, thus preventing the output surplus of the inverter 20 leading to the overvoltage charging of smoothing capacitors C1 and C2 . Then, even if the output of the motor fluctuates due to, for example, the stranding onto a curbstone, it is possible to follow the fluctuation rapidly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a power generator mounted on a hybrid vehicle (hereinafter referred to as "HV").

[0002]

2. Description of the Related Art HV is a general term for vehicles having characteristics common to a conventional engine vehicle and characteristics common to a pure electric vehicle, and generally includes a chargeable / dischargeable battery,
And a power generation device capable of charging the battery with the generated power. Examples of the power generation device include an engine and a generator driven by the engine (engine-driven generator), a solar cell that converts optical energy into electrical energy, and an electrochemical reaction such as a reverse reaction of electrolysis of water. There is a fuel cell or the like that converts chemical energy into electrical energy, and examples of the battery include a lead battery and a nickel hydride battery. These batteries and power generators
The discharge or power generation output is supplied to the load, for example, a motor for driving the vehicle or assisting vehicle acceleration, or a large power auxiliary device mounted on the vehicle such as an air conditioner drive system. Further, the battery has a buffer function of storing a surplus and compensating for a deficiency when power generation output is supplied from the power generator to the load. Also, HV is
Parallel HV (hereinafter “PHV”), series H
V (hereinafter, "SHV"), parallel series HV (hereinafter, "PSHV") and the like. Among them, the PHV is a vehicle in which a plurality of torque sources are mounted on a vehicle and the vehicle runs by using the outputs of the respective torque sources in addition and in parallel. , That is, a configuration in which the outputs of two types of torque sources, that is, an engine and an engine-assisting rotary electric machine, are added and used in parallel. The SHV is a vehicle that uses the output of a vehicle-mounted power generation device to drive a vehicle driving motor and travels using the output of the motor.
There is a configuration in which an engine-driven generator is used as a power generator. PSHV is a vehicle in which a PHV-like torque generation state and an SHV-like torque generation state are generated while switching or simultaneously in parallel, that is, a combined form of PHV and SHV. There are various other forms of realization of the HV.

[0003]

By the way, the characteristics of the battery will gradually deteriorate as the use years increase, and the battery may overheat depending on the use environment. In consideration of this point, it is preferable to determine whether or not the battery can be used at an appropriate time, and to control the battery to be electrically disconnected from the power generation device and the load when it is determined that the battery is unusable or inappropriate. . In this way, the vehicle can be propelled by using the power generation device (evacuation traveling in HV) while avoiding the use of a battery having some trouble (in the case where the load is a vehicle traveling motor). ). However, simply disconnecting would result in the loss of the buffer function, one of the functions that the battery performed before disconnection, so, for example, when the power output of the power generator exceeded the load consumption, The surplus of the power generation output loses its place. This surplus will eventually flow into any circuit or circuit component, such as a smoothing capacitor or other auxiliary equipment connected between the power generator and the load, and in some cases, the circuit or circuit component Damage (damage due to overvoltage charging in the example of a capacitor) can occur.

One of the objects of the present invention is to judge whether or not the battery can be used at an appropriate time, and to control the battery to be electrically disconnected from the power generator and the load when it is determined that the battery is unusable or unsuitable. By doing so
An object of the present invention is to enable so-called evacuation traveling in an HV. One of the objects of the present invention is to electrically disconnect a battery from a power generator and a load by switching the operation mode of the power generator accordingly, so that the battery cannot function as a buffer with the disconnection. Regardless, an object of the present invention is to prevent an excessive load from being applied to circuits and circuit components such as a smoothing capacitor. One of the objects of the present invention is to realize a control procedure or a device that can stably achieve each of the above objects irrespective of the road surface condition or the like, that is, is resistant to disturbances by switching the operation mode.

[0005]

In order to achieve the above object, there is provided a battery use determination means for determining whether a battery mounted on a hybrid vehicle together with a power generator and a load is usable, and the battery use determination means. The battery disconnecting means for electrically disconnecting the battery from the power generating device and the load when the battery is determined to be unusable, and the power generating output of the power generating device when the battery is disconnected by the battery separating means. And a non-control state operating means operating in a non-control state driven by the load.

In the present invention, when it is determined that the battery is unusable, the battery is electrically disconnected from the power generator and the load, and the power generator is in an uncontrolled state, that is, a state in which the generated output is driven by the load. Become. As described above, since the battery is electrically disconnected from the power generation device and the load when the battery is unusable, the HV according to the present invention is used.
In this case, evacuation traveling or the like can be executed in response to the occurrence of a battery failure. Further, although the battery cannot function as a buffer due to the disconnection, since the power generation output of the power generator is driven by the load, a load is not placed on a circuit or a circuit component disposed between the power generator and the load. . In addition, a strong disturbance performance can be obtained in which a power generation output driven by the load can be supplied stably irrespective of load fluctuations (when the load is a motor for driving a vehicle, climbing on a curb, slipping, or the like).

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows an example system configuration of an SHV to which the present invention is applied. In the SHV shown in this figure, a three-phase AC motor (for example, a permanent magnet excitation type synchronous motor) 10 is used as a vehicle traveling motor. As components for supplying drive power to the motor 10, a main battery 12 and a generator 14 are provided. The main battery 12 is, for example, a lead battery or a nickel hydride battery. The generator 14 is a three-phase AC generator (for example, a permanent magnet excitation type synchronous generator), and the engine 16
Driven by The main battery 12 and the motor 1
0, and between the generator 14 and the main battery 12, the power input from the DC terminals (+,-in the figure) is converted from DC to AC, and the AC terminal (U in the figure) is converted. ,
V, W) from the three-phase inverter 18
Or 20 is provided.

The motor-side inverter 18 incorporates three pairs of power transistors Q1 to Q6, three pairs of diodes D1 to D6 connected in anti-parallel thereto, and a smoothing capacitor C1. On the 12 side, the AC terminal is connected to the motor 10 side. Transistor Q
1 and Q2, Q3 and Q4, and Q5 and Q6 each make a pair, and are connected in the forward direction between the DC terminals of the inverter 18. The smoothing capacitor C1 is connected between the DC terminals of the inverter 18, and the power from the inverter 20 and the main battery 12 is applied to both ends of each of these transistor pairs after being smoothed by the capacitor C1. Therefore, the output torque (powering) of the motor 10 can be controlled by switching the transistors Q1 to Q6 in a pattern according to the accelerator operation, and the output torque (motor running) of the motor 10 can be controlled by switching in the pattern according to the brake operation. Regenerative power, and thus, regenerative power to the main battery 12 can be controlled. By turning off all the transistors Q1 to Q6, the inverter 1
8 can also be operated as a rectifier.

The generator-side inverter 20 incorporates three pairs of power transistors Q7 to Q12, three pairs of diodes D7 to D12, and a smoothing capacitor C2. The DC terminal is on the main battery 12 side, and the AC terminal is It is connected to the generator 14 side. The connection relationship between these circuit elements and terminals is the same as that in the inverter 18. The power output of the generator 14 is input from the connection point of each transistor pair, and the output between the DC terminals of the inverter 20 is smoothed by the capacitor C2. Therefore, transistors Q7 to
By switching Q12 in a pattern corresponding to the required power output, the power output of the generator 14 is rectified and boosted, and then output to the main battery 12 and the inverter 18 and the output can be controlled. Further, when the engine is started, the transistors Q7 to Q12 are switched,
The generator 14 can be operated as a starter motor. By turning off all the transistors Q7 to Q12, the inverter 20 can be operated as a rectifier. In the following description, transistors Q7 to Q12
Is called a “control state” or “inverter operation”, and a state in which all are turned off is called a “non-control state” or “inverter stop”.

Therefore, in the vehicle shown in FIG. 1, the output of the generator 14 which is an engine-driven generator is converted from AC to DC (rectified and boosted) by the inverter 20, and the obtained DC power is supplied to the inverter 20. The AC power is again converted into AC power, and the motor 10 can be driven using the obtained AC power. The main battery 1 is connected between the inverters 20 and 18.
2, the power output from the generator 14 does not need to strictly follow the power required for driving the motor 10. The surplus of the former with respect to the latter is stored in the main battery 12, and the shortage is mainly stored. It can be supplemented by the battery 12.
Further, regenerative braking for recovering braking energy from the motor 10 to the main battery 12 via the inverter 18 or the engine 1
6 can be started by the generator 14 (in this case, functioning as a motor) to start torque.

The operation of these inverters 18 and 20 is as follows:
IG (ignition) switch by vehicle operator, etc.
A control device 2 including an electronic control unit (ECU) and the like in response to operations of an accelerator pedal, a brake pedal, and the like.
2 controls. For example, in response to the ON operation of the IG switch, the control device 22 causes the system main relay (SMR) 24
To turn on the main battery 12 and the inverter 1
8 and 20 are electrically connected to the respective DC terminals. The control device 22 controls each transistor of the inverters 18 and 20 in response to the operation of the accelerator pedal, the brake pedal, and the like, and while receiving the feedback of the rotation speed Nm and the current Im of the motor 10 and the rotation speed Ne of the engine 16. By controlling the switching operation, the motor 10
Variably controls the output torque from the inverter and the power generation output via the inverter 20. The control device 22 also controls the main battery 12
Terminal voltage, state of charge (SOC) or charge / discharge current,
In addition to monitoring the temperature and the like and adjusting the output torque of the motor 10 according to these values, the SMR 24 is turned off when it is not preferable or impossible to continue using the main battery 12 such as overheating. Thereby, the electrical connection between the main battery 12 and the inverters 18 and 20 is cut off. It should be noted that, although illustration of the method of detecting the number of rotations, voltage, SOC, temperature, etc. is omitted, it is obvious to those skilled in the art that a known or well-known technique may be used as a method of detecting these various amounts. Will.

FIG. 2 shows an outline of an operation procedure of the control device 22. In response to the IG switch being turned on (100), the control device 22 turns on the SMR 24 (102) and inputs various detection quantities or state quantities from various parts of the vehicle (10).
4). The amounts input in step 104 include the accelerator opening, brake depression force, shift position, motor 1
0 rpm Nm, current Im, etc., the rpm N of the engine 16
e, SOC (or charge / discharge current), temperature, and the like of the main battery 12 can be exemplified. The control device 22 executes an evaluation on whether or not the main battery 12 is in a usable state at the present time, based on an amount related to the state of the main battery 12 among the input amounts, for example, an SOC / temperature of the main battery 12. (106).

As a result of the evaluation, the main battery 12 is deteriorated,
No overheating or other significant failures
When it is determined that can be used continuously (108), the control device 22 determines a torque command for the motor 10 using the map 200 (11).
0), and further determines a power generation command for the generator 14 (11).
2) After appropriately adjusting the determined torque command and power generation command, a switching control signal corresponding to the torque command is output to the inverter 18 and a switching control signal corresponding to the power generation command is output to the inverter 20 ( 11
4). As a result, the output torque of the motor 10 is controlled to a value corresponding to the torque command, and the power output of the generator 14 is controlled to a value corresponding to the power generation command. The circuit state of the inverter 18 at this time is equivalently the state shown in FIG. The control device 22 continues until the IG off operation is performed (116).
Steps 104 to 114 are repeatedly executed unless a situation such as occurrence of a failure in the main battery 12 is reached.
When the G-off operation is performed, predetermined end processing such as turning off the SMR 24 is executed (118).

The map 200 includes, for example, a rotational speed Nm.
This is a map giving characteristics of the maximum output torque Tmax.
When the map 200 having such contents is mounted, the control device 22 acquires from the map 200 the maximum output torque Tmax corresponding to the current rotational speed Nm input in step 104, and inputs the maximum output torque Tmax in step 104. The torque command is determined by a method such as apportioning the maximum output torque Tmax according to the current accelerator opening or the brake pedal force. The control device 22 also determines the power generation output according to the power to be supplied to the motor 10 via the inverter 18 and the SOC of the main battery 12 and so that the decrease in the efficiency of the engine 14 due to the increase and decrease of the power generation output is not as obvious as possible. . The power to be supplied to the motor 10 is a torque command and a rotation speed N.
m or from the current and voltage of the motor 10. Adjustment of the torque command and the power generation command is, for example,
The execution is performed in consideration of the realization status of the command value output in the previous cycle, the temperature of the inverters 18 and 20, and the like.

If it is detected in step 108 that the main battery 12 has some problem, for example, if the main battery 12 has a considerable deterioration or temperature rise, the control device 22 The main battery 12 is electrically disconnected from the inverters 18 and 20 by turning off the SMR 24 (120). Control device 22
After resetting the torque command up to that point to ensure control stability (122), the inverter 20 is shut down, that is, all the transistors Q7 to Q12 are turned off (124). As a result, the inverter 20
As shown in FIG. 4, a circuit state equivalent to the three-phase bridge rectifier (“non-control state”) is obtained, and the boosting function, that is, the generator 14 that is performed when functioning as an inverter (“control state”) is performed. The function of efficiently pumping the generated energy from the power cannot be performed. After shifting from the control state to the non-control state, the control device 22 inputs various detection amounts or state amounts from various parts of the vehicle similarly to step 104 (12).
6) Further, a torque command for the motor 10 is determined using the map 300 (128), and a switching control signal corresponding to the determined torque command is output to the inverter 18 (130). Note that it is not necessary to determine and output the power generation command here. The control device 22 includes an IG
Until the OFF operation is performed (132) Steps 126 to 1
30 is repeatedly executed, and a predetermined end process is executed in response to the IG off operation (134).

Among the operation procedures described above, a part of the feature of the present embodiment is that the state of the main battery 12 is evaluated (106), and as a result, when a failure is found, the SMR 24 is turned off. (120). As a result, the limp-home running can be performed when the main battery 12 is defective. Another part of the features of the present embodiment is that the control mode of the inverter 20 is switched to the non-control state when a failure is found in the main battery 12 (122 and thereafter). In the uncontrolled state, the inverter 20 is equivalent to a rectifier, the output of which will follow the fluctuations of the output of the motor 10, which is the load. In other words, the DC output power of the inverter 20 is always
Thus, the surplus of the former with respect to the latter does not flow into the capacitor C1 or C2. Therefore, no overvoltage damage of the capacitors C1 and C2 occurs.

The state in which the DC output power of the inverter 20 always coincides with the DC input power of the inverter 18 can be roughly realized by precise control of the inverter 20 in the control state. However, in reality, such control involves some control delay or has a certain limit in its followability, so that it has a drawback that it is vulnerable to unexpected disturbance. On the other hand, if the method of shifting to the non-control state is adopted as in the present embodiment, such a problem in followability does not occur, and therefore, it is stronger against unexpected disturbance. That is, even when the output of the motor 10 fluctuates instantaneously or steeply due to disturbances such as curb climbing and slipping, the DC output power of the inverter 20 driven by the load changes with the fluctuation of the output of the motor 10. Follow exactly. In this regard, the present embodiment is different from the configuration of JP-A-8-126115 in which the generator-side inverter is provided and the configuration of JP-A-7-336809 in which the target power generation follows the motor output when the main battery cannot be charged. (Without the generator-side inverter) is structurally different and provides a significant effect.

When the inverter 20 is operated in a controlled state and when it is operated in a non-controlled state,
As shown in FIG. 5, the former has a larger output in terms of both voltage and power. This is because the generated energy can be pumped more efficiently in the control state. In this respect, the operation in the uncontrolled state is characteristically inferior to the operation in the controlled state, but in the present embodiment, the operation in the uncontrolled state is limited to when the main battery 12 malfunctions. Employing operation in a state does not significantly affect the energy utilization efficiency of the vehicle as a whole. Further, since the DC output voltage of the inverter 20 in the non-control state is lower than that in the control state, when the inverter 20 is in the non-control state, the strict restriction is more than in the control state. Imposed on torque. That is, the maximum output torque characteristic of the motor 10 is:
Usually, the area restricted by the constant torque line (low rotation area)
And a region constrained by a constant power line (high rotation region), and the boundary between both regions is in a low rotation region as the maximum voltage applied between the DC terminals of the inverter 18 is lower. . Therefore, the rotation speed N is set as the maps 200 and 300.
When a map giving the characteristic of m vs. maximum output torque Tmax is used, for example, the map 200 is a thin solid line in FIG. 6, and the map 300 is a thick solid line in FIG.

The possibility of overvoltage damage to the capacitors C1 and C2 has been described as a problem when the SMR 24 is turned off while the inverter 20 is in the control state. In the present embodiment, such a problem occurs. Not that said. In the present embodiment, components that can avoid the damage and increase in the load can include not only the capacitors C1 and C2 but also various components between the inverters 18 and 20. FIG. 7 shows an example of such a component. As shown in the figure, an auxiliary machine 26 such as an air conditioner compressor which receives power from the main battery 12 to consume relatively large electric power, an auxiliary machine inverter 28 for controlling the auxiliary machine 26, an ECU constituting the control device 22, etc. The auxiliary battery 32, which is a battery for supplying the driving power to the auxiliary equipment 30, and the DC / DC converter 34 for charging the auxiliary equipment 30 can also be prevented from being damaged or increased in burden due to the supply of the surplus power from the inverter 20.

Further, in the control procedure described above, after it is determined that the main battery 12 has a problem, the SMR 24 is kept off until the driver or the like once turns off the IG and then turns it on again. This procedure is modified so that the main battery 12
Are returned to the normal state.
The process may proceed to step 104 when it is detected between. However, it is preferable that this transition process is performed only when the “failure” in the main battery 12 is clearly recognized as temporary. In addition, various modifications can be made to the above control procedure.

The application of the present invention is not limited to SHV, but the present invention can be applied to PHV, PSHV and the like.
An example applied to PHV is shown in FIG. Engine 1 in the figure
Numeral 6 is mechanically connected to the driving wheels, and the motor / generator 36 is arranged such that the added torque of the output torque of the engine 16 and the output torque of the engine 16 is transmitted to the driving wheels. The motor / generator 36 assists the engine 16 in the acceleration direction when operating as a motor, and assists in the deceleration direction when operating as a generator. The operation mode of the motor / generator-side inverter 38 includes a control state and a non-control state. The control state further includes a control state similar to the above-described inverter 18 and an inverter 20.
And a similar control state. In such a configuration as well, it is possible to turn off the SMR 24 when a problem occurs in the main battery 12 and supply the driving power to the auxiliary device 26 and the like with the power generation output of the motor / generator 36. By setting the inverter 38 in an uncontrolled state, it is possible to prevent overvoltage damage to the accessory inverter 28, particularly to a capacitor (not shown) between its DC terminals.

Further, the application of the present invention is not limited to a configuration using an AC rotating electric machine or an inverter.
For example, even in a configuration using a DC rotating electric machine and a step-up (step-down) chopper circuit, the step-up (step-down) is performed by using a switching element such as a transistor constituting the step-up (step-down) chopper circuit.
Since the pressure chopper circuit can be kept in the “uncontrolled state”, the present invention can be applied to such a configuration.

[0023]

As described above, according to the present invention,
When it is determined that the battery is unusable, the battery is electrically disconnected from the power generation device and the load, and the power generation device is operated in an uncontrolled state, that is, in a state where its power generation output is driven by the load. In addition to being able to perform limp-home running or the like in response to the occurrence of a malfunction, it is possible to prevent a load from being applied to the circuit or circuit components disposed between the power generator and the load due to the disconnection, and to be stable regardless of load fluctuations. Strong disturbance performance that can follow the load is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a system configuration of an SHV to which the present invention is applied.

FIG. 2 is a flowchart illustrating an operation procedure of the control device.

FIG. 3 is a circuit diagram showing a generator-side inverter equivalent circuit configuration in a control state.

FIG. 4 is a circuit diagram showing a generator-side inverter equivalent circuit configuration in a non-control state.

FIG. 5 is a characteristic diagram comparing and comparing the DC output performance of the generator-side inverter in a control state and a non-control state.

FIG. 6 is a characteristic diagram showing an example of a map.

FIG. 7 is a block diagram illustrating components between a generator-side inverter and a motor-side inverter.

FIG. 8 is a block diagram showing a main part of an example system configuration of a PHV to which the present invention is applied.

[Explanation of symbols]

10 motor, 12 main battery, 14 generator, 16
Engine, 18, 20, 28, 38 inverter, 2
2 control device, 24 SMR, 26, 30 accessories, 32
Auxiliary battery, 34 DC / DC converter, 36
Motor / generator.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02J 7/00 H02J 7/00 P H02M 7/72 H02M 7/72

Claims (1)

[Claims] 1. A battery use determination unit for determining whether a battery mounted on a hybrid vehicle together with a power generation device and a load is usable, and the battery is determined to be unusable by the battery use determination unit. Battery disconnecting means for electrically disconnecting the power generating device and the load from the load; and non-controlling operation of the power generating device in an uncontrolled state in which the power generation output is driven by the load when the battery is disconnected by the battery disconnecting means. A control device comprising: state operation means.