JPH02131369A - Car-loaded generator - Google Patents

Abstract

PURPOSE:To reduce the maintenance and inspection of an apparatus by constituting a part of a rectifier circuit from a controlled rectifier element and by turning OFF the controlled rectifier element, when the output voltage of the rectifier circuit exceeds a specified value, and by turning ON the element, when the voltage lowers by a certain range from the specified value. CONSTITUTION:When the output voltage Vc of a rectifier circuit 10 exceeds the set value Vr of a voltage setter 13, a command turning OFF a controlled rectifier element 11 is given them a comparator circuit 14 to a firing circuit 12. When the controlled rectifier element 11 is turned OFF, the output side voltage of the rectifier circuit 10 lowers by the discharge of a capacitor 5. When the voltage lowers to a return voltage, ON command is given again from the comparator circuit 14 to turn ON the controlled rectifier element 11. In this manner, while the controlled rectifier element 11 is ON-OFF controlled and the output side voltage of the rectifier circuit 10 is suppressed by the set value Vr of the voltage setter 13, the output voltage of a generator 2 is brought to a steady state by the control action of an automatic voltage regulator 3. Thus, the maintenance and inspection of an apparatus can be saved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is a power generation device, particularly a power generation device mounted on a car (large trailer, etc.) and used as a power source for large-capacity electrical equipment such as a refrigerated container. This article relates to an on-vehicle power generation device.

(Prior Art) In general, this type of on-vehicle power generator is a dedicated power generation type configured to drive a generator with a dedicated engine;
Alternatively, there is a hydraulic power generation type in which a hydraulic drive mechanism is provided on the output shaft of the traveling engine, and a generator is driven by a constant rotational output taken from the hydraulic mechanism. However, the former type has problems such as an increase in vehicle weight and installation space, and the latter type has problems such as complicating hydraulic pressure management and control mechanisms.

Therefore, in order to avoid these above-mentioned problems, as shown in Figure 2, the power generation station is directly driven by the driving engine, and the output is converted into constant voltage and constant frequency electric power by a power converter and then supplied to the load. In recent years, systems configured to do so have been considered.

In FIG. 2, reference numeral (1) denotes a rotating driving machine, which is, for example, an engine for driving an automobile such as a large trailer. (
2) is a brushless generator driven by the drive shaft (1). The reason why a brushless generator is used here is to eliminate contact parts and reduce maintenance and inspection. (3
) is an automatic voltage regulator that controls the output voltage of the generator (2) at a constant level, and (7) is a power converter that converts the output voltage of the generator (2) into a constant voltage and constant frequency. 4),
It consists of a capacitor (5) and an inverter circuit (6).

A power generation device configured in this way is non-contact, and everything is processed electrically to supply a constant voltage, constant frequency AC voltage to the load, so it can be simplified instead of complicated maintenance and inspection work. It will be done. In addition, since the generator is directly driven by the engine for propulsion, it has the advantage of saving space.

(Problems to be Solved by the Invention) However, it has been found that the power generating device configured in this manner also has the following drawbacks. In other words, in the case of a diesel engine, its rotation range is approximately 50 Orr during idling.
pm to the maximum rotation of approximately 250 rpm, and the speed changes are rapid due to sudden acceleration, gear downshifts, etc.

For this reason, even if the generator (2) is equipped with an automatic voltage regulator (3) as in the above configuration, if the speed changes suddenly, the automatic The voltage adjustment function cannot follow this, and the generator output voltage yacg overshoots as shown in FIG. 3(A). At that time, due to the overshoot voltage, the power converter (7)
There is a risk that an overvoltage will be applied to the power converter (7), causing destruction or deterioration of the circuit components that constitute the power converter (7).

This phenomenon is particularly noticeable when a brushless generator with a two-stage excitation circuit and a large control delay is used.

In addition, when the driving engine rotates at high speed, the actance of the generator winding appears to be high, so if load shedding is performed at this time, the voltage jump of the generator yacg will be abnormal as shown in Figure 4 (A). At this time as well, overvoltage VC is applied to the power converter (7).

Therefore, in order to protect the power converter (7) from this overvoltage, each circuit component must be made of an expensive high-voltage type, or a separate expensive one must be added between the generator (2) and the power converter (7). It is very expensive as it requires a complicated voltage regulator to absorb the overshoot of the generator (2), and a chopper device etc. must be installed in the DC circuit of the power converter (7). There was a drawback.

The present invention uses a simple circuit configuration to prevent overvoltage from being applied to the output side of the power converter, especially the rectifier circuit, even if the rotational speed of the drive machine suddenly increases or there is a load cutoff at high rotational speed. The objective is to provide an on-vehicle power generation system that is highly reliable, takes up little space, and requires less maintenance and inspection.

[Structure of the invention]

(Means for Solving the Problem) The present invention configures a part of the rectifier circuit with a controlled rectifying element, turns off the controlled rectifying element when the output voltage of the rectifying circuit exceeds a predetermined value, and lowers the voltage within a certain range from the predetermined value. It is configured to turn on.

(Function) In an on-vehicle power generator configured as described above, when the speed of the running engine rapidly increases due to sudden acceleration, gear downshift, etc., or when the output voltage of the generator increases due to load shedding, the rectifier circuit A part of the control rectifier element is turned off and acts to suppress the output voltage of the rectifier circuit.

(Example) Hereinafter, examples of the present invention will be described in Figures 1 and 3 (B), and Figure 4.
The explanation will be made with reference to FIG. 8, and the same parts as in FIG. 2 will be given the same reference numerals and the explanation will be omitted.

In Figure 1, (10) is a rectifier circuit in which a part of the diode constituting the conventional rectifier circuit (4) is replaced with a controlled rectifier (11), and (13) is a rectifier circuit (13) of the rectifier circuit (10). A voltage setting device (14) is used to set the maximum value of the output voltage, and a comparison circuit is used to compare the setting value of the voltage setting device (13) with the output voltage of the rectifier circuit (10). When the voltage becomes higher than the set value of the voltage setting device (13), a signal is output. Also, since this comparator circuit (14) has a slight hysteresis characteristic, the signal is output when it becomes lower than the return voltage determined by this hysteresis characteristic. Stop. (1
2) is a rectifier circuit (
10) is an ignition circuit that controls on/off of the control rectifying element (11). It goes without saying that a system abnormality signal may be added to the output side of the comparator circuit (14) so that the control rectifier (11) is turned off when a system abnormality occurs.

In the car generator of the present invention constructed in this manner, as in the conventional case, when the running engine suddenly rises or the load is cut off during high speed rotation, the output voltage V acg of the generator changes as shown in Fig. 3 (8).
), or overshoot as shown in FIG. 4(B). However, when the output voltage of the generator, that is, the output voltage Vc of the rectifier circuit (10) exceeds the set value Vr of the voltage setting device (13), the comparator circuit (14) sends a signal to the ignition circuit (12).
A command is issued to turn off the control rectifier (11), and an increase in the output voltage of the rectifier circuit (10) is suppressed.

When the control rectifier (11) is turned off in this way, the output side voltage of the rectifier circuit (10) decreases due to the discharge of the capacitor (5), and the voltage decreases to the return voltage determined by the hysteresis characteristic of the comparator circuit (14). Then, the comparator circuit (14) issues an ON command again and the control rectifier (11)
turns on. In this way, while the control rectifier (11) is controlled on/off and the output side voltage VC of the rectifier circuit (10) is suppressed to the set value Vr of the voltage setter (13), the automatic voltage regulator Due to the control action of , the output voltage of the generator (2) is brought into a steady state.

In this way, even if the running engine suddenly increases or the load is cut off during high speed rotation, the output voltage V of the rectifier circuit (10)
c does not exceed the set value Vr of the voltage setter (13), and no overvoltage is applied to the circuit components of the power converter, especially the circuit components on the output side of the rectifier circuit (10).

In addition, in the embodiment shown in FIG.
Although the case of a mixed bridge circuit is shown as the circuit configuration for 0), it is not limited to this, and any element that has sufficient withstand voltage and can be turned on and off can be used, and the circuit configuration can also be rectified or Needless to say, it can be applied to anything that has an on/off function.

〔Effect of the invention〕

In this invention, the speed of the traveling engine increases rapidly,
Even if the output voltage of the generator overshoots, the output voltage of the rectifier circuit can be limited to the setting value of the voltage setting device, so there is no need to use special high-voltage circuit components for the power converter. In addition, it is highly reliable because the brushless generator is directly driven by the running engine. This has the effect of being able to provide an on-vehicle power generator that is small and requires less maintenance and inspection.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the on-vehicle power generation device of the present invention, FIG. 2 is a circuit diagram showing a conventional on-vehicle power generation device, and FIG. , generator output voltage, capacitor voltage relational characteristic diagram, Figures 4A and B show load current, generator output voltage, of conventional and present invention,
Required in the capacitor voltage relationship characteristic diagram. 1...Driver 2...Alternator 3...Automatic voltage regulator 4...Rectifier circuit 5...Capacitor 6...Inverter 7...Power converter

Claims (1)

[Claims] A brushless generator is driven by a drive machine with a very wide range of rotational speed fluctuations and rapid speed changes, and after rectifying the output voltage of the generator into a DC voltage unrelated to frequency, a constant voltage, constant frequency generator is used. A power converter consisting of a rectifier circuit for converting into an alternating current voltage and an inverter circuit, in which a part of the rectifier circuit is composed of a controlled rectifier, and the output of the rectifier circuit is connected to the ignition circuit of the control rectifier. An on-vehicle power generation device characterized by having a function of turning off the control rectifying element when the voltage exceeds a predetermined value and turning it on when the voltage falls within a certain range from the predetermined value.