JP2879485B2 - Braking and auxiliary power units for internal combustion engines - Google Patents

Abstract

PURPOSE:To improve utilization efficiency of electric energy and to reduce weight of a power source by forming a DC circuit of an inverter for bilaterally converting electric energy between a polyphase AC circuit of a squirrel-cage polyphase induction machine coupled directly to an internal combustion engine and the DC circuit of an electrostatic capacity. CONSTITUTION:Electric energy is bilaterally transmitted by AC/DC- or DC/AC- converting it by an inverter 4 connected to a squirrel-cage polyphase induction machine 2 coupled directly to an internal combustion engine 1 and a DC side formed of an electrostatic capacity circuit 20. An inverter controller 5 controls the inverter 4 according to an output of a rotation sensor 6, a voltage of the circuit 20 and an output of a CT of a semiconductor switch circuit 12. When a brake force is applied to a rotation system, the machine 2 is operated as a generator to charge the circuit 20. On the other hand, when a drive force is applied to the system, charge of the circuit 20 is DC/AC-converted by the inverter 4 to drive the machine 2, thereby applying auxiliary power to the engine 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts mechanical energy generated when braking an internal combustion engine into electric energy and accumulates the same, and assists the accumulative electric energy when accelerating the internal combustion engine. It is used for a device that generates mechanical energy by supplying it to the device. The present invention is used in a device in which a rotating cage type polyphase induction machine is connected to a rotating shaft of an internal combustion engine, and the cage type polyphase induction machine acts as a generator during braking and acts as a motor during acceleration. The present invention relates to HIM
This device is suitable for mounting on a vehicle equipped with an auxiliary acceleration and auxiliary braking device sold by the present applicant under the name of R.

[0002]

2. Description of the Related Art The applicant of the present invention has published International Publication WO 88/88.
No. 0617 (International Application No. PCT / JP / 00157) discloses an electric braking and auxiliary acceleration device for a vehicle. As shown in FIG. 3, this device has a squirrel-cage polyphase induction machine 2 whose rotor is directly connected to an internal combustion engine 1, a secondary battery circuit 3 as a power storage means, and a direct current (DC) of the secondary battery circuit 3. The voltage is converted into an AC voltage having a frequency suitable for inducing a rotating magnetic field having a rotation speed lower than the shaft rotation speed of the cage type polyphase induction machine 2, and the converted voltage is applied to the cage type polyphase induction machine 2. Inverter circuit 4 for converting AC power from the multi-phase induction motor 2 into DC power, and an inverter control circuit 5 for generating a control signal for setting the frequency of the AC side voltage of the inverter circuit 4
And The inverter control circuit 5 includes means for generating a control command by a driver in accordance with driving of the vehicle.

A rotation sensor 6 is attached to the cage type polyphase induction machine 2, and a signal from the rotation sensor 6 is given to an inverter control circuit 5, and furthermore, a secondary battery relating to the state of charge of the secondary battery. Information from the circuit 3 is input.

A capacitor 7 and a semiconductor switch circuit 12 are connected to the output side of the inverter circuit 4, and a resistor 11 is connected through the semiconductor switch circuit 12.
The resistor 11 is configured to dissipate excessive electric energy that cannot be regenerated due to a large braking applied to the vehicle.

Further, a detection circuit 13 for detecting the output voltage of the inverter circuit 4 is connected to the secondary battery circuit 3 and the semiconductor switch circuit 12, and a resistor 11 is provided with a current detector 15 for detecting a change in current. Can be The current control circuit 15 is connected to a switch control circuit 14 for controlling the semiconductor switch circuit 12 according to the detection signal. The detection circuit 13 is connected to the switch control circuit 14.

This device is mounted on an automobile, recovers energy generated by braking when the automobile is braked as electrical energy, and stores the electrical energy. When the automobile accelerates, the stored electrical energy is converted into mechanical energy, and the axle is driven. This is to provide auxiliary power to the driving internal combustion engine.

In other words, the control circuit for controlling the inverter is such that in the acceleration mode in which the squirrel-cage polyphase induction machine is used as an auxiliary power unit for the internal combustion engine, the squirrel-cage polyphase induction machine applies a rotating magnetic field having a speed exceeding the rotation speed of the internal combustion engine. A deceleration mode in which the squirrel-cage polyphase induction machine is used as a braking device for an internal combustion engine and includes means for controlling its inverter circuit so as to apply a rotating magnetic field to the squirrel-cage polyphase induction machine at a speed lower than the rotation speed of the internal combustion engine. . In addition, the inverter circuit supplies the DC output of the electric energy stored in the power storage means as a polyphase AC output to the cage type polyphase induction machine in the acceleration mode, and outputs the polyphase AC output energy of the cage type polyphase induction machine in the deceleration mode. Includes circuit means for providing a DC output to the storage means.

In such a conventional device, the power storage means is a storage battery. In other words, the rated voltage on the DC side of the inverter is 200 to 300 V, and a storage battery having this rated voltage is used by connecting many lead-acid batteries for automobiles in series.

The applicant has designed and manufactured a practical device for the above-mentioned device, and has adopted it as a regular bus mainly operating in an urban area on a trial basis and has been able to perform many tests.

[0010]

From the results of this test,
The above-mentioned device is an extremely useful device that can be effectively recovered and used without simply dissipating the energy generated during braking. In the future, it will be applicable not only to large vehicles but also to passenger cars and small trucks. Has been found to have excellent performance, but when a large-sized lead-acid battery is to be mounted on a practical vehicle, the volume will be considerably large. Specifically, about 10 lead-acid batteries of 24V. Since it will be used by connecting in series, it is 0.2-0.
Approximately 4m ² ○ Increases body weight ... Specifically 200-300kg. ○ To take out tens of amperes of DC power at a voltage exceeding 200V, provide appropriate safety equipment for the human body It must be equipped with a mounting structure that is specifically designed to be installed in a solid box with an opening and closing door, and safety equipment that automatically shuts off the circuit when the door is opened. Since lead-acid batteries are devices that involve a chemical reaction, maintenance is required, such as observing the amount of electrolyte under certain conditions, measuring its specific gravity, and replenishing or replenishing the electrolyte. As the number of man-hours increases, the application to private cars becomes difficult. ○ In order to have a structure that is convenient for maintenance, it must be centrally located at one place. Battery internal resistance There is an energy loss due to resistance .... The energy recovered during braking cannot be used efficiently during acceleration. ○ Electrically accurate enough to use the current storage capacity under normal operating conditions for automatic control. The current storage capacity can be known fairly accurately by measuring the specific gravity of the electrolyte.
In a simple ammeter or voltmeter measurement, if there is a temperature change, the above-mentioned internal resistance changes and the accuracy is not always sufficient,
It turned out that there is a problem that it cannot be used as real-time control information.

The present invention has been proposed to solve the above-mentioned problems, and has led to a test. That is, an object of the present invention is to solve the above-mentioned problems and to provide an apparatus capable of widely implementing the principle of using energy efficiently in a small car.

[0012]

The present invention is characterized in that the electric storage means is a capacitance circuit. More specifically, the capacitance circuit can be configured by further electrically connecting a plurality of series circuits in which a plurality of unit capacitors are electrically connected in series. Since it can be realized by series-parallel connection of a plurality of unit capacitors, it is possible to adopt a structure in which the plurality of unit capacitors are dispersedly arranged in each part of the vehicle.

Further, as a concrete example of realizing the unit capacitor, when a commercially available electric double layer capacitor is used, this electric double layer capacitor is widely used for backing up an electronic circuit and has a withstand voltage of 2V. And a capacitor having a capacitance of about 500F. 150 of these are connected in series to have a withstand voltage of 300 V, and six more are connected in parallel to obtain a capacitor having a capacitance of about 20F.

[0014]

In the case of this concrete example, the breakdown voltage is 30
Since it is 0V, if this is used at a rated voltage of 200V,
The rated charge amount is 200 V × 20 F = 4000 coulombs (= ampere seconds). If the inverter under test is used, 4000 coulombs / 160 amps = 25 seconds, which indicates that it is possible to assist for about 25 seconds at a maximum voltage of 200 V and a maximum current of about 160 A. Since the operation is not performed continuously at the maximum rating, a device that works effectively even if there is continuous deceleration or acceleration for several tens of seconds in a normal operation state is obtained.

In the above example, a unit capacitor having a withstand voltage of 2 V and a capacitance of 500 F is used,
When the capacitors having a capacitance of about 20F are obtained by connecting them in series to have a withstand voltage of 300 V and further connecting them in parallel in six circuits, the number of unit capacitors is about 900, which is a realistic size at one place. When concentrated, it becomes the size of one tatami mat between Japan. And its weight is a fraction of the lead storage battery. When the capacitance circuit is used, no maintenance is required, so that it is possible to adopt a structure of distributing and arranging in any part of the automobile whatever the size as a whole and connecting them with electric wires. In addition, since there is no need for maintenance, the capacitance circuit itself can be sealed in a rigid insulating structure to ensure safety for the human body. In addition, since the capacitance circuit has essentially no internal resistance, the stored energy is not lost and the energy can be effectively used. Furthermore, since the amount of charge stored in the capacitance circuit is simply proportional to the terminal voltage at the time of release, the amount of charge stored can be known accurately and in real time by voltage detection, and can be used directly for control.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention.

The embodiment of the present invention is provided with a capacitance circuit 20 which is a feature of the present invention as a power storage means. The DC voltage of the phase induction machine 2 and the capacitance circuit 20 is converted into an AC voltage having a frequency suitable for inducing a rotating magnetic field having a rotation speed lower than the shaft rotation speed of the cage type polyphase induction machine 2. To the cage type polyphase induction machine 2 and an inverter circuit 4 for converting AC power from the cage type polyphase induction machine 2 into DC power, and a control signal for setting the frequency of the AC side voltage of the inverter circuit 4. And an inverter control circuit 5 for generating. The inverter control circuit 5 includes means for generating a control command by a driver in accordance with driving of the vehicle.

A rotation sensor 6 is attached to the cage type polyphase induction machine 2, and a signal from the rotation sensor 6 is supplied to an inverter control circuit 5, and further information on the state of charge of the capacitance circuit 20. Enter.

A capacitor 7 and a semiconductor switch circuit 12 are connected to the output side of the inverter circuit 4, and a resistor 11 is connected through the semiconductor switch circuit 12.
This resistor 11 dissipates excessive electrical energy that cannot be regenerated due to heavy braking applied to the vehicle.

Further, a detection circuit 13 for detecting the output voltage of the inverter circuit 4 is connected to the capacitance circuit 20 and the semiconductor switch circuit 12, and the resistor 11 is provided with a current detector 15 for detecting a change in current. Can be This current detector 15 is connected to a switch control circuit 14 for controlling the semiconductor switch circuit 12 according to the detection signal. The detection circuit 13 is connected to the switch control circuit 14.

In the acceleration mode in which the cage type polyphase induction machine 2 is used as an auxiliary power unit of the internal combustion engine 1, the inverter control circuit 4 causes the cage type polyphase induction machine 2 to have a speed exceeding the rotation speed of the internal combustion engine 1. In a deceleration mode in which a rotating magnetic field is applied and the squirrel-cage polyphase induction machine 2 is used as a braking device for the internal combustion engine 1, an inverter circuit is provided so as to give the squirrel-cage polyphase induction motor 2 a rotating magnetic field at a speed lower than the rotation speed of the internal combustion engine 1. The inverter circuit 4 is provided with a DC output of the electric energy stored in the capacitance circuit 20 as a polyphase AC output to the cage type polyphase induction machine 2 in the acceleration mode in the acceleration mode. The circuit includes circuit means for applying the polyphase AC output energy of the cage type polyphase induction machine to the capacitance circuit 20 as a DC output.

As shown in FIG. 2, the capacitance circuit 20 includes 150 unit capacitors C ₁ , C ₂ ,... C ₁₅₀ having the same capacitance (500 F, 2 V). Series circuits connected in series are further connected in parallel in six rows, and a total of 900 capacitors are arranged.

Further, each of these capacitors has a resistance R ₁ , R ₂ , R ₃ ,.
₁₅₀ are connected in parallel and 6
The columns are connected and arranged.

The reason why the resistors are arranged as described above is that even if each capacitor has the same standard capacitance, there is a slight variation due to manufacturing tolerances. , A difference occurs in the terminal voltages generated at the terminals. In order to prevent this, a resistor having little variation in manufacturing is connected in parallel for each capacitor so as to make the terminal voltage generated as uniform as possible.

In this example, as described above, 900 capacitors and resistors are used, respectively, but when these are arranged on a plane, they have an area and volume of about one tatami mat. However, since it is possible to disperse and dispose the group of capacitors and resistors in an unused space in the vehicle in a state of being electrically connected, the active space is not narrowed, and the battery of the conventionally used battery is not reduced. It can be extremely lightweight when compared to its weight.

In the above example, the capacitor and the resistor are set to 90
Although the number is zero, the number is not necessarily limited and can be set arbitrarily according to each vehicle type.

Here, as a specific example, a commercially available electric double layer capacitor has a withstand voltage of 2 V and a capacitance of 500 F.
00V, and when six circuits are connected in parallel, the capacitance becomes about 20F.

Since the withstand voltage is 300 V, the rated voltage is 2
When used at 00 V, the rated charge is 200 V × 20 F = 4000 coulombs (= ampere seconds), and the maximum current is 160 A according to the current inverter.
Therefore, 4000 coulombs / 160 amps = 25 seconds, and auxiliary power can be given for about 25 seconds with respect to electric power of maximum voltage 200V and maximum current 160A.

Next, the operation of the embodiment of the present invention configured as described above will be described.

First, when a braking force is generated in the rotating system, the inverter control circuit 5 generates a rotating magnetic field having a speed lower than the rotating speed of the rotor of the squirrel-cage polyphase induction machine 2 detected by the rotation sensor 6. A control signal is generated so as to be given to the stator section of the cage type multi-phase induction machine 2. At this time, the cage-type polyphase induction machine 2 operates as a generator, and the generated electric energy is converted into DC energy by the inverter circuit 4 and supplied to the capacitance circuit 20 as a charging current. When the braking torque is large and the capacitance circuit 20 cannot absorb this DC energy, the DC terminal voltage rises beyond a predetermined value, and the semiconductor switch circuit 12 detects this and detects the terminal of the capacitance circuit 20. To close the resistor 11.

On the other hand, when applying a driving force to the rotating system, the inverter control circuit 5 generates a rotating magnetic field having a speed higher than the rotating speed of the rotor of the cage type polyphase induction machine 2 detected by the rotation sensor 6. A control signal is generated so as to be given to the stator section of the cage type multi-phase induction machine 2. At this time, a DC current is extracted from the capacitance circuit 20, converted into a polyphase alternating current corresponding to the rotating magnetic field by the inverter circuit 4, and supplied to the cage type polyphase induction machine 2.

Here, the larger the difference between the rotation speed of the rotating magnetic field and the shaft rotation speed, the larger the brake torque and the driving force. In this embodiment, the ratio between the difference and the rotation speed of the rotating magnetic field, that is, the slip of the cage type polyphase induction machine 2 is approximately ±
It is set to be in the range of 10%.

Next, control of charging the capacitance circuit 20 will be described. The inverter circuit 4 is supplied with a control signal from the inverter control circuit 5 for applying a rotating magnetic field corresponding to the rotation of the rotor to the stator of the squirrel-cage polyphase induction machine 2. The inverter control circuit 5 includes a rotation sensor 6
, And information regarding the state of charge of the capacitance circuit 20 is input. The inverter control circuit 5 includes a microprocessor. In addition, the inverter control circuit 5 includes a unit that captures an operation control signal that changes depending on a driving condition by a driver's operation.

As described above, the inverter circuit 4 can supply the energy of the DC terminal to the AC terminal and can supply the energy generated in the AC terminal to the DC terminal. Further, the rotation speed of the rotating magnetic field is controlled by the control of the inverter control circuit 5 so that the squirrel-cage polyphase induction machine 2 becomes an electric motor, and a driving force is applied to the rotating shaft of the squirrel-cage polyphase induction machine 2 to provide an internal combustion engine. It can be operated as one auxiliary driving device. At this time, the electric energy charged in the capacitance circuit 20 is used.

The charging of the capacitance circuit 20 is continued by the generator connected to the internal combustion engine as long as the internal combustion engine is rotating, and the charging energy is increased by the operation of the starting motor or the operation of various outfitting devices. When used, it is controlled so as to reach a full charged state in the shortest possible time.

[0036]

As described above, according to the present invention, it is possible to reduce the weight of a power supply for an automobile and to improve the efficiency of use of electric energy. it can.

Further, since the capacitance circuit is used, maintenance is not required, and therefore, it is possible to dispersely dispose and seal in the insulating structure, thereby securing safety to a human body. In addition, there is an effect that the amount of stored power can be known accurately and in real time by voltage detection.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration example of a capacitance circuit according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cage type polyphase induction machine 3 Secondary battery circuit 4 Inverter circuit 5 Inverter control circuit 6 Rotation sensor 7 Capacitor 11 Resistor 12 Semiconductor switch circuit 13 Detection circuit 14 Switch control circuit 15 Current detector 20 Capacitance circuit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60L 11/12 B60L 7/20 H02J 7/00 H02J 7/14

Claims (4)

(57) [Claims] 1. A car-shaped polyphase induction machine connected to a rotating shaft of an internal combustion engine, power storage means, and a polyphase AC circuit of the cage-shaped polyphase induction machine and a DC circuit of the power storage means are bidirectionally connected. an inverter circuit for coupling by converting electric energy, in the braking and auxiliary power unit for an internal combustion engine and a control circuit for controlling this inverter circuit, said storage means is Ri capacitance circuit der, the capacitance The circuit consists of multiple unit capacitors electrically
More series circuits connected in series are electrically connected in parallel
Braking and auxiliary power unit of an internal combustion engine, characterized in that it is. 2. A rotary shaft of the internal combustion engine is directly connected to a rotary shaft of the cage-type polyphase induction machine, and the control circuit includes the cage-type polyphase induction machine as an auxiliary power unit for the internal combustion engine. In the acceleration mode, a rotating magnetic field having a speed exceeding the rotation speed of the internal combustion engine is applied to the cage polyphase induction machine, and in the deceleration mode in which the cage polyphase induction machine is used as a braking device for the internal combustion engine, the cage polyphase is set. Means for controlling the inverter circuit to apply a rotating magnetic field having a speed lower than the rotation speed of the internal combustion engine to the induction machine, wherein the inverter circuit is configured to output a DC output of electrical energy stored in the power storage means in the acceleration mode. Circuit means for providing the cage-type polyphase induction machine as a polyphase AC output, and in the deceleration mode, providing the polyphase AC output energy of the cage-type polyphase induction machine to the power storage means as a DC output. Braking and auxiliary power system for an internal combustion engine Motomeko 1 wherein. Wherein the internal combustion engine is an internal combustion engine for an axle drive mounted on a vehicle, the braking and auxiliary power unit for an internal combustion engine according to claim 1, wherein said unit capacitor is distributed to the automobile. 4. The capacitance circuit according to claim 1, wherein a resistor having the same resistance value is connected in parallel to each of the unit capacitors, and the resistors are connected in series.
A braking and auxiliary power unit for an internal combustion engine according to any one of the preceding claims.