JPS5833976A - Power converter - Google Patents

Abstract

PURPOSE:To efficiently operate a power converter without intermediary of a battery or the like by inputting a voltage obtained by connecting condensers to a solar battery array or the like through a voltage rising type high frequency chopper to an inverter and cooperating with an AC power system. CONSTITUTION:A condenser 2 is connected in parallel with a DC output 1 of a solar battery array or a wind power generator, thereby obtaining the just DC voltage, which is coverted to the second DC voltage through a voltage rising high frequency wave chopper 3 which has a condenser 4 at the output side, is converted via an inverter 5 into an AC voltage, which is then applied through a transformer 6 to an AC power system 7. Accordingly, the condenser 2 serves to suppress the voltage variation due to the high frequency pulsating current of the chopper 3 and the condenser 4 serves to reduce the input voltage variation of the inverter 5, thereby efficiently applying solar battery energy to the AC power system without providing secondary energy storage means.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power conversion device that efficiently converts power between a power system and a solar cell array.

In recent years, as energy sources have become increasingly scarce, new forms of energy use have been actively pursued.From the point of view of electrical energy, solar cells have been widely adopted in many ways as a viable means. -ru. Solar cells are solar cells that convert light energy into electrical energy.
The voltage that is the output due to light energy, i.e. its illuminance,
'& flow characteristics change. In order to stably convert this energy into the power grid, it is necessary to effectively extract the energy from the pond. Especially Taiyo IIL
This is a simple and efficient way to convert power for equipment that generates enough power to supplement household power consumption by arranging small sky thresholds such as pond array eaves and installing individual power conversion devices. A gikan that can be made is 1i1 better. Furthermore, it is desired that harmonics, noise, reactive power, etc. generated from the Fi power converter be suppressed as much as possible with such a scissors. In general, it is known that storage means such as single-hole batteries are used as a buffer means to prevent energy conversion from solar cells, but it is not the best method from the viewpoint of simplicity of storage. The object of the present invention was developed in consideration of the above-mentioned points, and is to efficiently transfer the variable solar energy to the electric power system with a configuration that does not require a secondary energy storage means. The purpose of the present invention is to provide a tortoise-to-power conversion scissors-tortoise for power conversion.

The invention will now be described with reference to one aspect.

Figure 1 shows the main circuit structure of an embodiment of the present invention! I! , where 1 is a solar cell array, 2 is a capacitor, Itd
Valve pressure shaping I14 wave chopper, 4 is DC smoothing capacitor,
jFi high lR & single phase power supply main bar, 6 is the output transformer, 1 is the single phase power supply. Released 11 by thick 1% pond array I! The fL & first DC output exceeds the audible frequency range, for example 20KHzl! The DC output of #42 is converted by the step-up type high chest wave transmitter 3 which is modulated by the frequency of the station wave number. At this time, the capacitor 2d performs an operation to suppress the voltage f fluctuation due to the frequency pulsation km. Therefore, the power from the Kameike array 1 has a pulsation component of approximately I#, and outputs an output of one foot. becomes possible. As shown in FIG. 2, the power from the solar cell array 1 has a maximum power limit depending on the illuminance, and the current value shown on the horizontal axis also relates to the W class. Therefore, in order to always draw the maximum power from the thick micrometer pond, it is necessary to monitor the current and voltage and control the pulse width of the transistor 31 of the step-up type high voltage transistor so as to convert the maximum power. .

The output IIflL of the external pressure type cylindrical wave chopper 3 is pulse-like, but the stain pressure is kept almost constant by the smoothing capacitor 4. The ratio of the first DC voltage that is the input of the step-up high-frequency chopper 3 to the DC voltage of the output 2 is selected so as to be large, but the configuration of the step-up high-frequency chopper 3 This is largely due to the fact that the chopper input current is not pulse-like and includes a certain S degree pulsation, but it is desirable to suppress power fluctuations from the solar cell array 1 as much as possible.

On the other hand, the inverter consists of a 5Fi voltage type single-phase transistor inverter and is a well-known one, but in order to convert power to the electric IL2 with established voltage, the voltage value of the electric current is tracked and the same phase as the voltage phase is determined. The appearance＼.

The inverter is pulse-variable M (PWM) controlled so that the power current, that is, the power factor of the power source, is 1, and the energy from the solar cell array 1 is converted.

・ In this practical example, the AC output is single-phase, so the inverter input power Fi fluctuates at twice the number of waves.
Voltage fluctuations can be made smaller by DC smoothing Contin +4, and there is little impact on fluctuations in energy consumption from thick batteries.
Not allowed. Roughly, the variation @ms number of inverter 5 is also audible.
By selecting a liquid more than IIl, the high frequency current on the inverter input side is also smoothed by the capacitor. Also, the inverter output current waveform has changed! Due to the high frequency and the presence of leakage inductance of the output transformer 6, even if the power source 7 is an infinite bus, low-quality power conversion with few harmonics is possible.

In this embodiment, a single-phase output inverter 5 is shown, but a three-phase power supply can be easily realized by configuring a three-phase output inverter. In this case, since the DC power is much smaller than that of a variable kbFi single-phase inverter, the capacitance of the smoothing capacitor may be sufficient to eliminate current ripples that vary with the modulation frequency of the inverter.

In the embodiment shown in Figure 1, a transistor was used as the power conversion element of the chopper or inverter, but power FETs, which have poor high frequency characteristics at the -power level, have also been integrated into the TL, and such elements can be used. By using the 3A704, a more efficient system can be realized.

In this way, the present invention provides power conversion test 1 for small scale photovoltaic power generation systems such as those for private use. Place it in the dormitory v! The configuration and operation for this purpose have been explained, and the beam energy that fluctuates depending on the illuminance of the sun can be converted into an electrodynamic or <1IEfA system. Due to the action of the step-up chopper shown in the present invention, the voltage and current from the solar cell have a small amount of pulsation.
It is possible to extract 'tZ'd energy from the pond. Since the switching frequency of the power transformer and inverter is lower than the switching frequency, each component can be made smaller, noise is reduced, and harmonics and reactive power to the power system can be suppressed. , can convert high-quality energy into the power grid.

[Brief explanation of the drawing]

Figure 1 shows an example of Honjomei's main circuit configuration, shown in Figure 2. , is a characteristic diagram of a pond array. ! ...Solar cell array, 2.4...Capacitor, 3
・・・Step-up type high-frequency chopper, 5...Thorax wave single-phase transistor inverter, 6...Output transformation recommendation, 7...
Single phase power supply, 3 no...transistor. Editor-in-Chief Agent Takehiko Ben Kenji Suzue Takehiko Commissioner of the Patent Office Shima 1) Tono Banju 1. Display of the case Special Peng@56-130529 No. 2, Name of the invention Power conversion device 3, Person making the amendment Relationship to the case Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4, Agent 7, Contents of the amendment (1) ) The specification (= the scope of claims stated in the statement is corrected as shown in the attached sheet. (3) On page 3, line 5 of the specification, “the drawings show the present invention” should be corrected to “
The drawings are corrected to ``The present invention relates to a solar cell.'' (4) "Constant output" on page 3, line 18 of the specification is corrected to "constant output according to sunlight." (5) The statement "The step-up harmonic chopper 3 has a large . . ." on page 4, line 8 to line 1815 of the specification is corrected as follows. ``Considering the configuration and operation of the boost type high frequency chopper 3, the input terminal 4 includes a pulsation component in the form of a pulse, but the power fluctuation from the solar cell array I is suppressed as much as possible by the capacitor 2; therefore, the amount of solar radiation - (6) On page 6, line 7 of the specification, next to "It becomes possible." 1: "Also, in the above embodiment, it was stated that in the case of solar cells, 4 and 2 solar cells are used. The same applies to wind power generation, including variability.'' Insert the following statement. (7) Change “Illuminance (secondary direction)” on page 6, line 11 of the specification to “
"Depending on illuminance or wind power." (8) "In the specification, page 6, line 14 to line 16,"
Therefore, it can be done from solar cells. ” is corrected to “become.” 2. Claims: A power conversion device that connects a solar cell array or wind power generation DC output with an AC power system & After converting the second DC voltage into a DC voltage of $2 through a step-up high frequency converter with a capacitor, and converting the second DC voltage into a DC voltage with an inverter, it becomes a DC voltage through an output transformer. A power conversion VJ direct that is characterized by being interconnected with a magnetic system.

Claims (1)

[Claims] In a power conversion device that interconnects a solar cell array and an AC power system, the first DC voltage obtained by connecting all the contents to the solar cell array in a uniform manner is added to its output cost. It is converted to a second DC voltage via an external pressure type high frequency chopper with a smoothing capacitor, and wil! 7L2 1#
t. A power conversion device, characterized in that the voltage is converted into an alternating current voltage by an inverter and then connected to the alternating current power system via a power output transformer.