JPH0447528B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field to which the Invention Pertains] The present invention relates to an internal combustion engine-driven alternating current generator comprising an internal combustion engine and an alternator driven by the internal combustion engine, and an internal combustion engine-driven alternating current generator. The machine is equipped with a power converter that can convert the AC power generated by the machine into DC power, and uses the internal combustion engine as the drive source to drive the wheels via the AC motor. The present invention relates to a braking system for an internal combustion engine-driven electric-electric hybrid vehicle, which is capable of driving wheels via the AC motor using a DC power supply connected to the AC motor as a drive source.

[Prior art and its problems] In large construction machinery vehicles such as large dump trucks and self-propelled crane trucks, the equipment mounted on the vehicles is small and lightweight and easy to maintain. Furthermore, in order to obtain continuous non-mechanical restraint braking for continuous descents, the wheels are driven from the conventional internal combustion engine through clutches, reduction gears, and differential gears. From a mechanical system, an internal combustion engine drives an alternating current generator, and a semiconductor converter converts the output of this alternator into variable voltage/variable frequency alternating current power to drive an alternating current motor connected to the wheels. Internal combustion engine driven electrical systems have come into use.

FIG. 1 is a main circuit connection diagram showing a conventional example of an internal combustion engine-driven electric vehicle whose wheels are driven by a three-phase induction motor. In FIG. 1, a synchronous generator 2 is coupled to an internal combustion engine 1 such as a diesel engine or a gasoline engine, and the output of the synchronous generator 2 is converted into direct current by a diode rectifier 3. Note that 23 is an internal combustion engine driven alternating current generator consisting of an internal combustion engine 1 and a synchronous generator 2. A so-called DC intermediate circuit 4 connecting the DC side of the diode rectifier 3 and the DC sides of GT inverters 8L and 8R, which will be described later, has a filter including a filter reactor 4L and a filter capacitor 4C for smoothing. This smoothed DC power is input to a GTO inverter 8 as a power converter consisting of, for example, a gate turn-off thyristor.
The induction motor 9 is driven by the output. In addition,
GTO inverter 8 is GTO inverter 8 for left wheel.
The induction motor 9 is composed of a left wheel induction motor 9L and a right wheel induction motor 9R. The induction motor 9L that drives the left wheel is a GT for the left wheel.
From the O inverter 8L, the induction motor 9R that drives the right wheel is connected to the GT inverter 8R for the left wheel.
These GT inverters 8L and 8R convert the aforementioned smoothed DC power into variable voltage/variable frequency AC power, so the rotational speed and torque of the induction motors 9L and 9R are That is, the traveling speed and traction torque of the vehicle are controlled by the forward conversion operation of GT inverters 8L and 8R. Also, inverter 8 for the left wheel
L, electric motor 9L, and inverter 8 for the right wheel
Since the electric motors 9R can each control R independently, it is possible to smoothly travel around curves. Also, even if slippage occurs between the wheels and the ground,
This slippage can also be quickly eliminated by controlling the torque and rotational speed of the wheels.

A series connection circuit of a braking resistor 6 and a chopper 7 is connected to the DC intermediate circuit, and when it is desired to operate the vehicle under braking, the induction motors 9L and 9R are operated as an induction generator, and the GT inverters 8L and 8R are connected to the DC intermediate circuit.
By performing a reverse conversion operation, the AC power from the induction generator described above is converted to DC power and sent to the DC intermediate circuit. Reduce vehicle speed. At this time, adjustment of the power consumed by the braking resistor 6 is achieved by controlling the chopper 7.

In the conventional example shown in Fig. 1, this vehicle can sufficiently and stably obtain traction force and braking force depending on the speed, but the driving force during power running is generated by the internal combustion engine.
Since the energy is supplied from the brake resistor 6, it is inefficient in terms of energy utilization, and a large-capacity resistor is required to continuously consume all the braking power in the braking resistor 6 for slow braking when descending a slope. Having to install such a large braking resistor 6 not only reduces the payload and space that can be used for the intended purpose of the vehicle, but also has the disadvantage that fuel efficiency deteriorates due to the weight of the braking resistor 6. has.

[Purpose of the invention]

This invention provides a brake system for internal combustion engine-driven electric-electric hybrid vehicles that can save energy during power running, which consumes a large amount of energy, and improve fuel efficiency by reducing the size and weight of the braking resistor used during braking. The purpose is to provide equipment.

[Key points of the invention]

This invention relates to an internal combustion engine in which DC power is supplied from an alternator driven by the internal combustion engine to a DC intermediate circuit using a diode rectifier, and this DC power is converted to AC power by an inverter to drive an induction motor. This method focuses on the fact that in electric drive vehicles, the DC intermediate circuit voltage is almost constant regardless of the vehicle's running speed, and if there is equipment that can supply power from the ground to the vehicle while it is running, it is In addition to minimizing power running by the internal combustion engine, which is relatively fuel-inefficient, the diode rectifier is replaced with a converter that can reversely convert direct current to alternating current, and during braking, the induction motor is used to drive the vehicle. By using the returned braking power to operate the alternator as an electric motor to apply engine braking, the braking power consumed by the braking resistor is reduced, and the braking resistor is made smaller and lighter.

Therefore, the internal combustion engine driven electric type according to the present invention -
The braking device for an electric hybrid vehicle is a braking device for an internal combustion engine-driven electric-electric hybrid vehicle comprising a reversible power converter, a DC intermediate circuit, and a power converter, the reversible power converter comprising: , converts the AC power generated from the internal combustion engine-driven AC generator into DC power and supplies it to the DC intermediate circuit 4, and when the vehicle decelerates, the energy returned from the AC motor that drives the wheels is used. The power is consumed by the internal combustion engine-driven alternating current generator via the power converter and the DC intermediate circuit 4, and the DC intermediate circuit has a filter consisting of a filter reactor and a filter condenser,
connected to the rear stage of the reversible power converter and the front stage of the power converter, and connectable to the trolley wire via a reverse current blocking diode, the power converter is connected to the rear stage of the DC intermediate circuit, It is characterized in that the DC power smoothed by the DC intermediate circuit is converted into AC power of variable voltage and variable frequency to drive the AC motor.

[Embodiments of the invention]

FIG. 2 is a main circuit connection diagram showing an embodiment of the present invention, and the content of the present invention will be explained in detail below with reference to FIG.

In FIG. 2, a synchronous generator 2 is coupled to a diesel engine 1 as an internal combustion engine, and a diode rectifier 3 is connected to a bridge.
and a thyristor inverter 21 which is also bridge-connected are connected in antiparallel to form a reversible power exchanger 22. The reversible power converter 22 configured as described above rectifies the AC power from the synchronous generator using the diode rectifier 3 and supplies it to the DC intermediate circuit, and also supplies the braking power returned to the DC intermediate circuit to the thyristor inverter. 2
It is also possible to convert the power into alternating current power in step 1 and operate the synchronous generator 2 as a motor.

The so-called DC intermediate circuit 4 is a filter reactor 4L.
and a filter capacitor 4C to remove pulsating components of the supplied DC power. This smoothed DC power is input to GT inverters 8L and 8R as power converters composed of gate turn-off thyristors, and induction motor 9L coupled to the left wheel.
8L from the GT inverter, and 8R from the induction motor 9R connected to the right wheel.
AC power is supplied separately from each GT inverter, and the variable voltage/variable frequency AC power output from these GT inverters 8L and 8R allows the vehicle to operate at the desired towing torque and running speed. be able to.

Also, a ground rectifier 1 as a DC power source on the ground.
1 supplies DC power to the trolley wire 12,
By bringing a pantograph 13 installed in the vehicle as a current collecting means into contact with the trolley wire 12, this DC power is taken into the vehicle and supplied to the DC intermediate circuit. In mines where vehicles such as large dump trucks are used, in order to install ground power equipment, trolley wires, etc. at the lowest possible cost, the DC power source is simple as shown in the ground rectifier 11 and regenerated. Since it does not have the ability to absorb power, a blocking diode 14 is provided between the DC intermediate circuit and the ground rectifier 11 as a means to prevent braking power from flowing back to the ground rectifier 11.

During power running, the DC power from this ground rectifier 11 is transferred to the DC intermediate circuit and GT inverters 8L, 8.
Since the power is supplied to the induction motors 9L and 9R via R, there is no need to use the diesel engine 1, which has relatively low fuel consumption, and the diesel engine 1 is used only when traveling in an area where the trolley wire 12 is not installed. I am trying to switch to energy from

During braking operation, for example, when the vehicle is going down a slope and the speed of the descent is to be suppressed, the diesel engine 1 is placed in an idling state regardless of whether DC power is being received from the ground rectifier 11. put. During braking, this energy from the vehicle passes through the wheels to the left and right induction motors 9L and 9.
Since R is rotated, this induction motor 9L
and 9R become an induction generator and generate AC power,
GT inverters 8L and 8R convert this AC power into DC power and send it to the DC intermediate circuit. At this time, since the synchronous generator 2 is generating AC voltage as the engine is idling as described above, the reversible power converter 22 consisting of the diode rectifier 3 and the thyristor inverter 21 is connected to the normal power system. This variable power converter 22 is capable of reverse conversion operation in the same way as the separately excited converter.
As a result, the electric power sent from the induction motors 9L and 9R to the DC intermediate circuit is received, and AC power is further sent to the synchronous generator 2. However, at this time, when DC voltage is applied to the DC intermediate circuit from the ground rectifier 11, the GT
If the GT inverters 8L and 8R are controlled so that the voltage of the DC power returned via the inverters 8L and 8R is higher than the DC voltage from the ground rectifier 11, the braking power is transferred to the ground rectifier 11 by the blocking diode 14. There will be no backflow.

The synchronous generator 2 receives the AC power reversely converted as described above and becomes a synchronous motor, and its speed is higher than the speed of the diesel engine 1 during idling. In this way, when the speed of the diesel engine 1 increases during idling, the engine brake acts, and the energy held by the vehicle going downhill is eventually absorbed by this engine brake, so the vehicle's running speed increases. This will reduce speed. In the embodiment shown in FIG. 2, the brake resistor 7 as the braking resistance control means
If the thyristor inverter 21 and the brake resistor 7 are properly controlled, what ratio of energy for braking the vehicle to the engine brake and the braking resistor 6 can be determined. Since it is possible to freely set whether or not the brake force is absorbed by the brake force, the braking resistor 6 and the brake resistor 7 may not be used in extreme cases. Therefore, the capacities of the braking resistor 6 and the chopper 7 can be made much smaller than in the past.

FIG. 3 is a main circuit connection diagram showing a second embodiment of the present invention. In this Fig. 3, a diesel engine 1 as an internal combustion engine, a synchronous generator 2, a filter capacitor 4C and a filter reactor 4L are shown.
A DC intermediate circuit 4 having a filter consisting of a filter, a GTO inverter 8 as a power converter consisting of a left wheel GTO inverter 8L and a right wheel GTO inverter 8R, a left wheel induction motor 9L and a right wheel induction motor 9R. An induction motor 9, a ground rectifier 11 installed on the ground as a DC power source, a trolley wire 12, and a pantograph 1 as a current collecting means.
3. The reference numeral, name, purpose, and function assigned to the blocking diode 14 as a backflow blocking means are the same as those in the embodiment shown in FIG. 2, so a description thereof will be omitted.

In FIG. 3, a thyristor inverter 31 is provided between the synchronous generator 2 and the DC intermediate circuit as a reversible power converter capable of converting direct current to alternating current and back converting alternating current to direct current. Furthermore, a thyristor rectifier 32 as a braking resistance control means whose AC side is connected to the AC side of the thyristor inverter 31 and a braking resistor 33 connected to the DC side of the thyristor rectifier 32 are provided. With this configuration, when the vehicle is in power running, it runs at a desired speed using either the DC power from the ground rectifier 11 or the energy from the diesel engine 1, and when the vehicle is in braking mode, the induction motor 9L, The voltage of the braking power returned from 9R to the DC intermediate circuit is made higher than the DC voltage from the ground rectifier 11 to prevent DC power from flowing into the ground rectifier 11. If this is reversely converted, engine braking will be applied in the same way as in the embodiment shown in FIG. Furthermore, the thyristor rectifier 32
Since the braking effect can be obtained by the energy consumed by the braking resistor 33 by controlling Can be set to

FIG. 4 is a main circuit connection diagram showing a third embodiment of the present invention, which is composed of a diesel engine 1 as an internal combustion engine, a synchronous generator 2, a filter capacitor 4C, and a filter reactor 4L. A DC intermediate circuit 4 having a filter, a GTO inverter 8 as a power converter consisting of a GTO inverter 8L for the left wheel and a GTO inverter 8R for the right wheel, an induction motor consisting of an induction motor 9L for the left wheel and an induction motor 9R for the right wheel. 9. A ground rectifier 11 installed on the ground as a DC power source, a trolley wire 12, a pantograph 13 as a current collecting means,
The symbols, names, uses, and functions given to the blocking diode 14 as a backflow blocking means and the thyristor inverter 31 as a reversible power converter are the same as those in the second embodiment shown in FIG. 3, so their explanation will be omitted. . In the third embodiment shown in FIG. 4, a series connection circuit of a thyristor regulator 42 as a braking resistance control means and a braking resistor 43 is star-connected to the output circuit of the alternator 2. Although the braking power consumed by the braking resistor 43 can be changed by the thyristor regulator 42, the other operations during power running and braking are the same as in the second embodiment shown in FIG. Note that the series connection diagram of the thyristor rectifier 42 and the braking resistor 43 may be connected to the output circuit of the alternator 2 by delta connection.

The reversible power converter and braking resistance control means illustrated in the first to third embodiments of the present invention can operate in the same way even if a semiconductor switching element such as a GT thyristor or a transistor is used instead of a thyristor. can be done, and these are consistent with the spirit of the present invention.

〔Effect of the invention〕

According to this invention, DC power obtained by converting the output of an alternator connected to an internal combustion engine and DC power obtained from a ground power source via a blocking diode are used as driving energy for a vehicle. When ground power can be used during power running, it receives power from the ground instead of the internal combustion engine, which is relatively fuel-efficient, reducing operating costs, and when braking, power is returned from the drive motor. The resulting energy is consumed by the engine brake via an alternator or by braking resistance. Since the capacity of the braking resistor can be reduced by an amount corresponding to the energy absorbed as engine braking, the braking resistor can be made smaller and lighter. Therefore, it is possible to increase the payload and space, which is the original purpose of the vehicle, and furthermore, by reducing the weight, it is also possible to improve fuel efficiency during power running.

[Brief explanation of the drawing]

Fig. 1 is a main circuit connection diagram showing a conventional example of an internal combustion engine driven electric vehicle, Fig. 2 is a main circuit connection diagram showing an embodiment of the present invention, and Fig. 3 is a main circuit connection diagram showing a second embodiment of the present invention. FIG. 4 is a main circuit connection diagram showing the third embodiment of the present invention.
FIG. 2 is a main circuit connection diagram showing an embodiment of the present invention. 1... Diesel engine as an internal combustion engine,
2...Synchronous generator, 3...Diode rectifier, 4
...DC intermediate circuit, 4C...filter capacitor, 4L...filter reactor, 6...braking resistor, 7...chopper, 8...GTO inverter as motor side converter, 8L...GTO inverter for left wheel, 8R...GTO inverter for right wheel,
9... Induction motor, 9L... Induction motor for left wheel, 9R... Induction motor for right wheel, 11... Ground rectifier, 12... Trolley wire, 13... Pantograph, 14... Backflow blocking diode, 21... ...Thyristor inverter, 22...Reversible power converter,
23... Internal combustion engine driven alternator, 31... Thyristor inverter, 32... Thyristor rectifier, 33... Braking resistor, 42... Thyristor regulator, 43... Braking resistor.

Claims (1)

[Scope of Claims] 1. A braking device for an internal combustion engine-driven electric-electric hybrid vehicle comprising reversible power converters 22, 31, a DC intermediate circuit 4, and a power converter 8, wherein the reversible power The converters 22 and 31 convert AC power generated from the internal combustion engine-driven AC generator 23 into DC power and supply it to the DC intermediate circuit 4,
In addition, when the vehicle decelerates, the energy returned from the AC motor 9 that drives the wheels is consumed by the internal combustion engine-driven AC generator 23 via the power converter 8 and the DC intermediate circuit 4. The DC intermediate circuit 4 includes a filter reactor 4
It has a filter consisting of L and a filter capacitor 4C, and is connected to the rear stage of the reversible power converter 22 and the front stage of the power converter 8, and is connectable to the trolley wire 12 via the backflow blocking diode 14. The power converter 8 is connected after the DC intermediate circuit 4 and converts the DC power smoothed by the DC intermediate circuit 4 into variable voltage/variable frequency AC power to drive the AC motor 9. A braking device for an internal combustion engine-driven electric-electric hybrid vehicle, characterized in that: