JPH0274150A - Chopper - Google Patents

Abstract

PURPOSE:To suppress output voltage boost by varying the output from a feedback control circuit such that an operated commutation angle can be achieved. CONSTITUTION:When input voltages Ei1, Ei2 from a DC power source 1 vary abruptly, in a feedback control circuit 10 for controlling the output voltage constant, an operating circuit 21 performs operation of formula I based on the result detected through a voltage detector 20. Output from the feedback control circuit 10 is varied based on the output from the operating circuit 21 such that an operated commutation angle alpha can be achieved. Consequently, the response speed of the feedback control circuit 10 is increased and the commutation angle of a switching element 5 can be varied from alpha1 to alpha2 with no delay. By such arrangement, the output voltage E0 from a chopper circuit 9 is not influenced by the input voltage boost but held at a constant level and thereby a load 19 is protected from application of excessive voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chopper device used, for example, as an auxiliary power supply device for a vehicle.

[Conventional technology]

Fig. 4 is a circuit diagram showing a conventional auxiliary power supply device for a vehicle as disclosed in, for example, Japanese Patent Application Laid-Open No. 56-12866. DC high speed circuit breaker 3 is DC high speed circuit breaker 2
4 is an input filter capacitor (smoothing capacitor) connected between one end of the DC reactor 3 and the negative electrode side of the DC power supply 1;
5 is a chopper switching element consisting of an anti-parallel circuit of a GT○ thyristor and a diode, 6 is a chopper flywheel diode connected in parallel with the filter capacitor 4 via switching element 5, and 7 is a chopper output DC reactor.

8 is a chopper output filter capacitor as an output filter capacitor connected in parallel with the flywheel diode 6 via the DC reactor 7; 9 is the filter capacitor 4, the switching element 5, the flywheel diode 6, the DC reactor 7, and the filter A chopper circuit consisting of a capacitor 8; 10 is a feedback control circuit; this circuit 10 includes a voltage detector 11 for detecting the terminal voltage of the flywheel diode 6; Voltage detector 11
The voltage comparator 13 compares the detected voltage with the set voltage of the voltage setter 12, and the gate pulse generator 14 supplies and applies a pulse corresponding to the output of the voltage comparator 13 to the gate of the switching element 5. has been done.

Further, the voltage comparator 13 includes a resistor 15.1 provided in each output path of the voltage detector 11 and the voltage setter 12.
6, an amplifier 17, and an integrating capacitor 18. 19 is a load.

Next, the operation will be explained. When the DC high-speed circuit breaker 2 is turned on, the voltage of the DC power supply 5 is applied to the filter capacitor 4 via the DC reactor 3. Then, the switching element 5 performs a timing operation according to a command from the feedback control circuit 10 at a conduction angle α such that the input voltage of the load 19 becomes a constant voltage.

However, as shown in FIG. 5(a), when the input voltage E1m suddenly changes to E+2 at time T0,
The conduction angle α of the switching element 5 controlled by the output value of the feedback control circuit 10 is.

As shown in FIG. 5B, if the output voltage of the chopper circuit 10 is Eo, α, > α2 (α = E.

Since there is a response time delay of the field pack control circuit 10 during the period 1' until the El process reaches α == Eo, the output voltage Eo during this period is as shown in FIG.

(EPL>EO) transiently, and an overvoltage is applied to the load 19.

[Problem to be solved by the invention]

Since the conventional chopper device is configured as described above, there is a problem in that the output voltage increases in response to a transient upward fluctuation in the input voltage, and an overvoltage is applied to the load.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a chopper device that can suppress upward fluctuations in the output voltage when the input voltage fluctuates upwardly.

[Means for Solving Problem 8] The chopper device according to the present invention calculates the conduction angle of the chopper switching element and provides feedback to obtain the conduction angle when the input voltage rises and fluctuates above a specified value. It is equipped with an arithmetic circuit that forcibly changes the output value of the control circuit.

[Function J] The chopper device according to the present invention uses a feedback system #i@path so that when the input voltage rises and fluctuates above a specified value, the arithmetic circuit calculates the conduction angle of the chopper switching element and obtains the conduction angle. By forcibly changing the output value of , the response speed of the feedback control circuit is accelerated,
Suppresses output voltage rise.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, in which the same parts as in FIG. 4 are given the same reference numerals,
A voltage detector 20 detects the input voltage E1, and although the illustrated example detects the terminal voltage of the input filter capacitor 4, it may directly detect the terminal voltage of the DC power supply l.

21 is an arithmetic circuit, and this arithmetic circuit 21 performs the following (( 1) Calculate the equation to find the conduction angle α of the switching element 5.

Els Elf, Ett Eat The output value of the feedback control circuit IO is forcibly changed to obtain this flow angle α.

Next, the operation of the above embodiment will be explained.1 Normally, as described above, the output voltage is controlled to a constant value by the feedback control circuit 10, but as shown in FIG. Input voltage EI1 from source 1. is the same E1m
When there is a sudden change in the voltage, the arithmetic circuit 21 detects the voltage
The above equation (1) is calculated based on the detection result of 0.

Then, the output value of the feedback control circuit 10 is changed using the output of the calculation port J121, for example by reducing the value of the integrating capacitor 18, so as to obtain the flow angle α determined by the above calculation.

As a result, the response speed of the feedback control circuit 10 becomes faster, and the conduction angle of the switching element 5 is adjusted to α1 as shown in FIG.
In order to change the output voltage from α2 to α2, the output voltage EO of the chopper circuit 9 is held at a constant value without being affected by the rising fluctuation of the input voltage, as shown in FIG. 2(c), and no overvoltage is applied to the load 19. Prevent this from happening.

Figure 3 shows D D C (D 1rect D 1g1ta
This is an explanatory diagram of control (1 Control).
The input voltage shown in a) is sampled and detected as shown in FIG. The conduction angle of the switching element is determined as shown in Figure (d). In other words, the input voltage changes from Els to E
When it changes to 1□, the flow angle is changed from α1 to α2 to make it smaller.

In the above embodiment, the output value of the feedback control circuit 10 is forcibly controlled when the magnitude of the input voltage increases and fluctuates beyond the specified value. The same control may be performed in both cases, or both controls may be performed selectively.

〔Effect of the invention〕

As described above, according to the present invention, when the input voltage fluctuates beyond a specified value, the output value of the feedback control circuit is forced to calculate the conduction angle of the chopper switching element and obtain the conduction angle. Since I configured it to change to
The conduction angle α of the chopper switching element is controlled without delay to fluctuations in the input voltage, and the output voltage can be maintained at a constant value, which has the effect of reliably preventing overvoltage from being applied to the load. .

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a chopper device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the device when the input voltage fluctuates, FIG. 3 is an explanatory diagram of DDC control, and FIG. 4 is a diagram of the conventional chopper device. FIG. 5 is a circuit diagram showing the chopper device, and is an explanatory diagram of the operation of the device when the input voltage fluctuates. 5 is a chopper switching element, 9 is a chopper circuit,
10 is a feedback control circuit, and 21 is an arithmetic circuit. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 3 Patent applicant Mitsubishi Electric Corporation

Claims (1)

[Claims] a chopper circuit having a chopper switching element;
A chopper comprising a feedback control circuit that compares the output voltage of the chopper circuit with a preset reference voltage and controls the chopper switching element based on the comparison result to control the output voltage to a substantially constant value. In the apparatus, when the input voltage of the chopper circuit fluctuates beyond a specified value, a conduction angle of the chopper switching element corresponding to the fluctuation is calculated, and an output value of the feedback control circuit is adjusted to obtain the conduction angle. A chopper device characterized by comprising an arithmetic circuit that forcibly changes.