JP3891129B2 - Vehicle power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular power supply device that enables power supply to a load that should not stop power supply even when a vehicle engine is stopped.
[0002]
[Prior art]
Some vehicles are equipped with electrical devices that are in a bad condition when the power supply is stopped even when the engine is stopped. An example of such a vehicle is a freezer car.
A freezer car is used to transport food and the like while it is frozen, and is equipped with electrical equipment such as a compressor. While the engine is rotating, power is supplied from a generator driven by the engine, but is not supplied when the engine is stopped. Therefore, if it is desired to maintain the refrigeration function, the engine could not be stopped even if the vehicle stopped.
[0003]
However, recently, in consideration of the environment, when a vehicle is stopped due to unloading or the like, it is strongly required to stop the engine, and it is no longer common sense to stop. However, when the engine is stopped, power generation is also stopped and the refrigeration function is impaired.
In view of this, it has been considered that power can be supplied to an electric device such as a compressor even when the engine is stopped.
FIG. 3 is a diagram showing a configuration related to refrigeration of a conventional refrigeration vehicle. In FIG. 3, 20 is a refrigeration vehicle, 21 is a generator, 22 is an in-vehicle battery, 23 is an engine, 24 is a first compressor, 25 is a pipe, 26 is a refrigerator, 27 is a second compressor, 28 is a motor, and 29 is The second compressor device 30 is a plug.
[0004]
The pipe 25 is a pipe for circulating the refrigerant to the refrigerator 26. The first compressor 24 is connected to the engine 23. The engine 23 is driven while the engine 23 is rotating, and the refrigerant is circulated by the first compressor 24.
When the engine 23 is stopped for unloading or the like, the plug 30 is inserted into an outlet of an external commercial power source, and the second compressor device 29 is operated. That is, the motor 28 is rotated by the external commercial power source, and the second compressor 27 is driven. Thereby, even when the engine is stopped, the refrigerant is circulated and supplied to the refrigerator 26, and the refrigeration function is maintained.
[0005]
However, there is not always an outlet for an external commercial power source at the place where the cargo is unloaded. If not, the refrigeration function cannot be maintained. In view of this, a vehicle power supply device has been considered that maintains the refrigeration function even when the engine is stopped in a place where there is no external commercial power supply.
FIG. 5 is a diagram showing an example of such a conventional vehicle power supply device (Japanese Patent Laid-Open No. 11-4506). In FIG. 5, 40 is an engine, 41 is a generator, 42 is a rectifier circuit, 43 is a pressure regulating circuit, 44 is an inverter, 45 is a plug, 46 is a motor, 47 is a compressor, 47 is a compressor device, and 49 is a bidirectional DC. DC converter, 50 on-vehicle battery, 51 controller, 60 isolation transformer, 61 primary coil, 62 secondary coil, 63 and 64 switching elements, 65 reactors, 66 and 67 switching elements is there.
The controller 51 is for controlling the operation of the voltage regulator circuit 43, the inverter 44, and the bidirectional DC-DC converter 49.
[0006]
The generator 41 is a generator that generates a three-phase 200V alternating current, and the plug 45 is a plug for connecting to a 200V external commercial power source. And the voltage of the vehicle-mounted battery 50 is 24V. The voltage adjusting circuit 43 is a circuit for adjusting the voltage, and the inverter 44 performs conversion between DC and AC. The bidirectional DC-DC converter 49 converts the high-voltage direct current to the low-voltage direct current when supplying a charging voltage to the in-vehicle battery 50, and when operating the compressor device 48 by the in-vehicle battery 50, Convert from direct current to high voltage direct current.
[0007]
The operation in each case is as follows.
(1) When the engine 40 is rotating and the generator 41 is generating electricity, the alternating current generated through the path of the generator 41 → the rectifier circuit 42 → the pressure regulator circuit 43 → the inverter 44 is supplied to the compressor device 48. And actuate it. On the other hand, at the same time, a low-voltage direct current (about 24 V) generated through the path of the generator 41 → the rectifier circuit 42 → the bidirectional DC-DC converter 49 is supplied to the in-vehicle battery 50 and charged.
[0008]
(2) When the engine 40 is stopped and an external commercial power source can be used, the plug 45 is inserted into an outlet of the external commercial power source. External commercial power is supplied to the compressor device 48 to operate it. On the other hand, the low-voltage direct current generated through the path of plug 45 → inverter 44 → regulator circuit 43 → bidirectional DC-DC converter 49 is supplied to the in-vehicle battery 50 to charge it.
[0009]
(3) When the engine 40 is stopped and there is no external commercial power supply, the AC generated by the path of the on-vehicle battery 50 → the bidirectional DC-DC converter 49 → the pressure regulating circuit 43 → the inverter 44 Is supplied to the compressor device 48 to operate it.
Other conventional literature relating to vehicle power supply devices include Japanese Patent Laid-Open Nos. 7-75208 and 9-65504.
[0010]
[Problems to be solved by the invention]
However, the conventional example shown in FIG. 5 has the following problems.
The first problem is that the in-vehicle battery is rapidly deteriorated and its life is shortened. The second problem is that the circuit configuration becomes complicated and the cost increases. The first problem is that every time the engine is stopped in a place where there is no external commercial power supply, electric power is supplied from the in-vehicle battery 50 to the compressor device 48. The amount of electric power is much larger than on-vehicle auxiliary equipment (radio etc.), and the amount of discharge is large. Therefore, the amount of charge that is performed after the engine starts to rotate is also increased. That is, discharging and charging at a large depth are frequently repeated, and the in-vehicle battery 50 is rapidly deteriorated and its life is shortened.
[0011]
Next, as a second problem, the generator 41 used in the conventional example has a commercial power supply voltage (eg, 200 V) so as to be compatible with the compressor device 48 operating with a commercial power supply (eg, 200 V). ) Is used. Therefore, in order to charge the in-vehicle battery 50, it is necessary to provide a bidirectional DC-DC converter 49 that reduces the battery voltage (eg, 24V). This complicates the circuit configuration and increases the cost.
An object of the present invention is to solve the above problems.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a vehicle power supply device comprising a generator driven by an engine and generating a rectified output, and a vehicle power supply circuit to which an input is supplied from the generator. Includes a first circuit switch that switches between the second contact and the first contact connected to the generator, and a DC boost circuit that receives a direct current from the first circuit switch and performs boost control. A second circuit switch having a first contact connected to one output terminal of the DC booster circuit and a second contact connected to a second contact of the first circuit switch; and the second circuit A power storage device connected between the switch and the other output terminal of the DC boost circuit, an inverter connected to the output side of the DC boost circuit, an input current, an input voltage, and an output to the DC boost circuit Based on each voltage detection signal, the DC booster circuit and A controller for controlling the inverter, and the first and second circuit switchers are respectively switched to the first contact side to boost the output voltage of the generator by the DC boost circuit. The power storage device is charged while being supplied to the inverter, and the charge voltage of the power storage device is boosted by the DC boost circuit by switching the first and second circuit switchers to the second contact side. A power supply device for a vehicle is provided that is supplied to the inverter.
[0013]
Note that an electric double layer capacitor can be used as the power storage device. Moreover, it is good also as a structure which connects the vehicle-mounted battery which supplies electric power to a vehicle-mounted auxiliary machine with a generator with the said vehicle power supply circuit.
[0014]
(Work)
During engine rotation, the DC output of the generator driven by the engine is input to a DC booster circuit, the boosted voltage is converted to AC by an inverter, and power is supplied to an AC load (such as a compressor device). At the same time, the power storage device is charged with the boosted voltage. When the engine is stopped, the circuit is switched by the circuit switch, the charging voltage of the power storage device is input to the DC booster circuit, and the boosted voltage is supplied to the inverter.
As a result, even if the engine is stopped and the generated voltage cannot be obtained, it is possible to continue operating the AC load.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a vehicle power supply device of the present invention. In FIG. 1, 1 is an engine, 2 is a generator, 3 is an in-vehicle battery, 4 is a vehicle power supply circuit, 5 is a circuit switch, 6 is a current detector, 7 is a reactor, 8 is a diode, 9 is a switching element, 10 Is a diode, 11 is a DC booster circuit, 12 is a controller, 13 is a circuit switcher, 14 is a power storage device, 15 is an inverter, 16 is a motor, 17 is a compressor, and 18 is a compressor device.
[0016]
The engine 1, the generator 2 and the in-vehicle battery 3 are the same as those conventionally mounted on a vehicle, and the compressor device 18 is the same as that conventionally mounted on a refrigeration vehicle. The vehicle power supply circuit 4 is newly proposed in the present invention.
The vehicle power supply circuit 4 includes a circuit switch 5, a DC booster circuit 11, a controller 12, a circuit switch 13, a power storage device 14, and an inverter 15.
[0017]
The circuit changers 5 and 13 have fixed contacts A and B and a movable contact C, respectively. The movable contact C of the both switches to the fixed contact A side when the engine 1 rotates, and the fixed contact B when the engine 1 stops. It is switched in conjunction with the side.
The DC booster circuit 11 includes a reactor 7, a diode 8, a switching element 9, and a diode 10 connected in antiparallel to the switching element 9. The degree of boosting is determined while detecting the voltage on the input side and the voltage on the output side of the DC booster circuit 11, and boosting control based on the voltage is performed by controlling the on / off duty ratio of the switching element 9. Note that the configuration itself of the DC booster circuit 11 is known.
[0018]
As the power storage device 14, a battery or a capacitor (particularly an electric double layer capacitor) can be used. The usable voltage range of a normal battery is about 9.6 to 14.4 V, but the usable voltage range of the capacitor is from 0 V below and is wide. In addition, the capacitor has a feature that it does not deteriorate much (long life) even if charging and discharging at a large depth are repeated frequently.
[0019]
Since the power storage device 14 is charged with a voltage obtained by boosting the voltage of the generator 2 (which is substantially the same as the voltage of the in-vehicle battery 3) by the DC boost circuit 11, the charging voltage (accumulated voltage) is Of course higher than voltage.
The current detector 6 is provided for monitoring the input current to the vehicle power supply circuit 4. Since the power storage device 14 can be charged with a large current, if the amount of stored power is small, an excessive current may flow and cause the harm of lowering the generator voltage. In order to avoid this, the current is monitored, and the duty ratio of the switching element 9 is controlled so as not to become an excessive current.
[0020]
The inverter 15 converts the incoming DC voltage into an AC voltage suitable for operating the compressor device 18.
The controller 12 is based on the current detection signal from the current detector 6, the voltage detection signal on the input side of the DC boost circuit 11, the voltage detection signal on the output side, and the like, and the DC boost circuit 11 (the switching element 9 therein). And the operation of the inverter 15 is controlled.
[0021]
Next, the operation of the present invention will be described separately when the engine is rotating and when the engine is stopped.
(1) When the engine is rotating When the engine 1 is rotating and the generator 2 is generating power, the circuit switches 5 and 13 are switched so that the movable contact C is turned on to the fixed contact A as shown in FIG. Then, the generated voltage of the generator 2 is not only supplied to the vehicle-mounted battery 3 and the auxiliary machine as usual, but is also supplied to the vehicle power supply circuit 4.
The generated voltage supplied to the vehicle power supply circuit 4 is boosted by the DC booster circuit 11, charges the power storage device 14, and is supplied to the inverter 15. The inverter 15 converts the input direct current into alternating current suitable for an alternating current load (compressor device 18) connected to the output side.
[0022]
(2) When the engine is stopped If the AC load (compressor device, etc.) mounted on the vehicle is to be operated even when the engine is stopped, the circuit switchers 5 and 13 are turned on with the movable contact C turned on to the fixed contact B. Switch to
FIG. 2 is a rewrite of FIG. 1 in which the circuit switches 5 and 13 are switched in this way so that the circuit operation can be easily understood. That is, in the present invention, the stored voltage is used as an input during non-power generation when the engine is stopped. The reference numerals correspond to those in FIG.
[0023]
When switching in this way, the power storage device 14 is connected to the input side of the DC booster circuit 11 via the circuit switches 5 and 13.
Since the power storage device 14 is not yet discharged at the beginning of the connection, its voltage is high. Therefore, at that time, the control by the DC booster circuit 11 may be a control that hardly boosts the voltage. Although it decreases over time, it can be compensated by the control of the inverter 15 to a slight extent. However, if the amount of decrease becomes so large that the discharge progresses and the compensation control of the inverter 15 is not in time, the control in the DC booster circuit 11 gradually increases the boosting degree. In this way, the required alternating current is supplied to the compressor device 18.
Thus, even when there is no external commercial power supply when the engine is stopped, it is possible to continue supplying alternating current to the compressor device 18.
[0024]
FIG. 4 is a diagram showing a configuration related to refrigeration of a refrigerator car to which the vehicle power supply device of the present invention is applied. The reference numerals correspond to those in FIGS. A difference from the configuration of FIG. 3 is that a vehicle power supply circuit 4 as shown in FIG. 1 is mounted and connected so that the output of the generator 21 is also input to the vehicle power supply circuit 4. In the freezer wheel 20, the freezing operation can be performed anywhere as described below.
(1) When the engine 23 is rotating, the refrigeration operation is performed by the first compressor 24 that is directly driven by the engine 23.
(2) If there is an external commercial power outlet at the place where the engine is stopped for unloading or the like and the engine is stopped, the plug 30 is inserted therein. Then, the 2nd compressor apparatus 29 act | operates with an external commercial power supply, and freezing operation is performed.
(3) If there is no external commercial power outlet when the engine is stopped for unloading or the like and the engine is stopped, the circuit switches 5 and 13 in the vehicle power circuit 4 are switched. Then, the 2nd compressor apparatus 29 act | operates by using the electrical storage apparatus 14 as a power supply, and freezing operation is performed.
[0025]
【The invention's effect】
As described above, the vehicle power supply device of the present invention has the following effects.
(1) The effect of the invention of claim 1 When the engine is stopped and the generator is also stopped, the charging voltage of the power storage device that has been charged during power generation is changed by switching the circuit connection. Used as input voltage. If the boosted voltage is input to the inverter, the required AC output can be obtained and the AC load can be operated. Therefore, even if there is no external commercial power source where the engine is stopped, the AC load can be operated.
[0026]
(2) Effect of the invention of claim 2 In addition to the effect described in the preceding paragraph, there is an effect that the power supply to the auxiliary machine can be entrusted to a dedicated battery.
(3) Effect of the Invention of Claim 3 In addition to the effect described in the item (1), there is an effect that the life of the power storage device can be extended.
[Brief description of the drawings]
FIG. 1 is a diagram showing a power supply device for a vehicle according to the present invention. FIG. 2 is a diagram showing a case where a stored voltage is used as an input during non-power generation when the engine is stopped. FIG. 4 is a diagram showing a configuration related to refrigeration of a refrigerator car to which the vehicle power supply device of the present invention is applied. FIG. 5 is a diagram showing an example of a conventional vehicle power supply device.
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Generator, 3 ... Vehicle-mounted battery, 4 ... Vehicle power supply circuit, 5 ... Circuit switching device, 6 ... Current detector, 7 ... Reactor, 8 ... Diode, 9 ... Switching element, 10 ... Diode, 11 DESCRIPTION OF SYMBOLS ... DC booster circuit, 12 ... Controller, 13 ... Circuit changer, 14 ... Power storage device, 15 ... Inverter, 16 ... Motor, 17 ... Compressor, 18 ... Compressor device, 20 ... Refrigeration vehicle, 21 ... Generator, 22 ... In-vehicle Battery, 23 ... Engine, 24 ... First compressor, 25 ... Pipe, 26 ... Refrigerator, 27 ... Second compressor, 28 ... Motor, 29 ... Second compressor device, 30 ... Plug, 40 ... Engine, 41 ... Generator , 42 ... Rectifier circuit, 43 ... Regulator circuit, 44 ... Inverter, 45 ... Plug, 46 ... Motor, 47 ... Compressor, 48 ... Compressor device, 4 ... bi-directional DC-DC converter, 50 ... vehicle battery, 51 ... controller

Claims (3)

A vehicle power supply device comprising a generator driven by an engine to generate a rectified output, and a vehicle power supply circuit to which an input is supplied from the generator,
The vehicle power supply circuit
A first circuit switch that switches between a second contact and a first contact connected to the generator;
A DC booster circuit that receives DC from the first circuit switcher and performs boost control;
A second circuit switch in which a first contact is connected to one output terminal of the DC booster circuit, and a second contact is connected to a second contact of the first circuit switch;
A power storage device connected between the second circuit switcher and the other output terminal of the DC booster circuit;
An inverter connected to the output side of the DC booster circuit;
A controller for controlling the DC booster circuit and the inverter based on detection signals of input current, input voltage, and output voltage to the DC booster circuit;
By switching each of the first and second circuit switchers to the first contact side, the output voltage of the generator is boosted by the DC boost circuit and supplied to the inverter and the power storage device is charged.
The vehicle wherein the first and second circuit switchers are respectively switched to the second contact side to boost the charging voltage of the power storage device by the DC booster circuit and supply it to the inverter. Power supply. 2. The vehicle power supply device according to claim 1, wherein a vehicle-mounted battery for supplying power to the vehicle-mounted auxiliary device is connected to a generator together with the vehicle power supply circuit. 3. The vehicle power supply device according to claim 1, wherein an electric double layer capacitor is used as the power storage device.

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