JPS60113627A - Power source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a pulse width modulation inverter system using a solar cell as a power source, and a power supply device that operates in parallel to supply power to a load by operating a commercial power system in parallel. be.

(B) Prior art Generally, private residences, etc. C: In the self-generation equipment for solar cells that is applied, in order to effectively utilize solar energy, a storage battery is installed to store power, and the power is generated by the solar cells. All of the power generated by the solar cells can be effectively utilized by accumulating all of the power in the storage battery, and the power generation equipment can be linked to the commercial power system.

Electric power generated by solar cells is regenerated into the commercial power system, and the full effective power is utilized.

However, if all of the storage batteries are used, it becomes expensive due to the need for J-memory storage batteries, and the maintenance of the J-memory storage batteries is time-consuming, and power loss occurs when charging the storage batteries. There is an inconvenience that arises.

Even when connecting to the commercial power system at the back end, there are many technical problems and legal problems when obtaining permission for implementation.
Both lack practicality.

Therefore, the power generation equipment and an inverter that converts the DC power generated by the power generation equipment into AC power are used. /- is L. A power supply device with so-called parallel operation is constructed by connecting the pre-meeting blood cell liner in parallel with the load, and the power supplied by the inverter system does not exceed the total power demand of the load by t. In this way, both systems are operated to supply the load, so that so-called cross-flow, in which power from the inverter system is regenerated to the commercial power system, does not occur.

The professional circuit diagram disclosed in FIG. 1 is a power supply device similar to the embodiment of Japanese Patent Application No. 706110/1983 proposed earlier by the present inventors, and is the basic circuit of the present invention. . According to this diagram, the output voltage (hereinafter referred to as output voltage) CII from the inverter system (3) and the primary voltage (hereinafter referred to as system voltage) aC of the open torque system (4) are phase synchronized. , describes the process in the prior art of transitioning to a state of phase synchronization between the output current from the inverter system (hereinafter referred to as output current) and the current flowing through the load (5) (hereinafter referred to as load current). do. Figure 1 and patent application 1982
Differences from No.-70640 include the addition of an AC filter indicated by code (24), a linkage reactor indicated by '(, f C2), and a detection unit (91(L31flO1(14
A zero crossing point detection circuit (c#13) that detects the zero crossing point of the analog output of J and outputs a digital signal indicating it.
Inoi+i=M is added, and the bidirectional Inoi Sochi (19) that switches the analog signal is used as a selection switch for the digital signal.

FIG. 2 shows an embodiment of the phase comparator discharge area shown in FIG. 1 by g=3 (flI). In this figure (-), (26) is a phase comparator, (3) is a low-pass filter, (
The glue is a voltage collateral oscillator (hereinafter abbreviated as FVOO).

C/111 is a phase control circuit. Output voltage e of the selected inverter system
The electrical and grid voltages ea, iji, become input signals to the phase comparator (26). phase compa v-9
1i6) C generates a voltage according to the phase difference between these two input signals, and after this voltage signal has high frequency components removed by the low-pass filter η, the voltage signal is converted to the v c Oe1
Added to 81. This V OOt2B+ outputs a frequency proportional to the applied voltage, and this output controls the phase of the inverter (2) via the phase control circuit (29), and the phase of the output voltage eX and the grid voltage θC is adjusted. Synchronize. In such a place 3) PL below 1st loop circuit C
A method of transitioning from the above voltage phase synchronized state to the current phase direction Jul state using the L circuit will be explained with reference to the vector diagram in FIG. Figure 3 (- shows the state in which the phase and magnitude of the output voltage 6I and the pressure ea in the system are all the same. At this time, the shell current IL is all supplied from the open power system (4). be done.

t, C Next, with the shin pressure phase synchronized as shown in Fig. 3 fBl, the output voltage ex is increased by 4 sho IEIOJ, and the output current iz2 is caused to flow. Here, the bidirectional switch (17) selects all of the output currents i and 944 and applies them to the phase comparator t2G) to shift to the C current phase synchronization state. FIG. 3 is a vector diagram showing this state.

However, when transitioning from the state iBl in Figure 3 to the state shown in Figure 3 (0), a relatively large output current flows, so the current exceeds the ridge current ih in the C commercial power system (4 1. Purpose of the Invention The present invention has been made in view of the problems of the prior art as described above. The object of the present invention is to provide an inverter control method that prevents the output current from the inverter system from exceeding the load current.

(4) Configuration of the Invention A pulse width modulated inverter system using a solar cell as a power source and a commercial power system are connected in parallel, and both systems are operated so that the power supplied by the inverter system does not exceed the total power requirement of the load. A power supply device that supplies power to the load by
The output current of the inverter system exceeds the load current in the process of transitioning from a phase synchronized state between the voltage of the power system and the output voltage of the inverter system to a phase synchronized state between the output current of the inverter system and the load current. The inverter system is provided with means for controlling the pulse width of the output current of the inverter system to prevent regeneration of the output current to the commercial AC power supply that occurs when transitioning from the voltage phase synchronization state to the current phase synchronization state. It is something.

(E) Example Hereinafter, an example of the present invention will be described in detail in accordance with FIGS. 1, 4, and 5.

(30) is a phase shift circuit consisting of °C connected between the selection switch and bidirectional switch 9 ση in FIG. A control signal is sent to the circuit (to)) and the bidirectional switch circle.

a central processing unit (hereinafter abbreviated as CPU) capable of advancing or delaying the phase of the output signal from the bidirectional switch (I) by the phase shift circuit (to);
The aPU (20) also sends control signals to a selection switch rule different from the bidirectional switch (lη).

The phase detection circuit (to) receives the digital signal output from the detection circuit C by determining the lead or lag in phase of the two output signals of the selection switch G(1).

Here, there are two unexplained circuit components f, which will be briefly explained.

In FIG. 1, (11 is a solar cell, (2) is a pulse width variable sub-inverter whose input terminal is connected to the solar cell (1) and together with the solar cell (1) constitutes a two-pulse width modulation inverter system (3); (4) is a commercial power system connected in parallel with the inverter system (31 and negative system (51),
(6) is an electromagnetic switch installed between the solar cell (1) and the inverter (2), and (7) is a booster installed between the inverter (2) and the load (5). , (8) is the input terminal installed between the transformer (7) and the load (5) and (') (4Ji, 11■ is the output line of the inverter (2)). and a first and second voltage detection unit which is connected to the power line and detects the output voltage of the inverter system (31) and the system voltage of the commercial power system (4), respectively, and outputs a detection signal.

(121 is an inverter system installed in the output line and the load line, respectively (two current transformers that take out the output current and load current of 31, fi31). The input terminal of the first and second current detectors-05) which detects the output current and load current and outputs a detection signal is Electricity/1lIJt
3rd voltage detection which is connected to l+ and detects the output 'voltage of the solar cell (1) and outputs the entire detection signal? J[L (LGha each tjHJ[5(91, (101, 131, (141, (
An AD converter that converts each detection signal consisting of 151 analog signals into a detection signal consisting of a digital signal and outputs it, u! When the output voltage of the inverter system (1) and the system voltage of the open magnetic system (4) are synchronized,
and a synchronization detection section that outputs the same JIJ] ia-8 when the phase of the output ih current of the impark system (3) and the load/current are in phase with ISi.

C! lj is tl which receives each digital signal from the ADi converter 00 and the same JυJ signal and outputs each control signal;
r! OP U, 121), which is the li1 part, outputs a control pulse to the inverter (2) and changes the pulse width from 0PTJ to 0), and outputs it.
U 2 (Turn on, turn on, turn off from 11.

Below, two operations S of the antistatic embodiment will be explained.

The output voltage of the solar cell (1) is detected from the third voltage detection part a5, and the detection signal is converted to 8)? It is determined whether the output voltage has reached a predetermined value sufficient to operate the inverter (21't-1'fE) from the OP U C1 (H = inputted to the CPU (201) via the
If the predetermined value has been reached, an ON control signal is output from the -CPU (2 (1)) to the switch drive unit +22, and the switch (6
) is turned on, the output and appropriate pressure of the solar heavy oil (1) is applied to the inverter (2), the inverter system (3) starts operating, and the first... Second voltage detection section (9L (10)
The output voltage of the inverter system (3) and the system voltage of the commercial power system (4) which are open on both sides 1 of the power switch 9 (8) in the "off" state are detected, and the C detection signals are output respectively. The detection signal is passed through the D241 device (C6).
cCPUt201 inputs 0PU (0PU until the absolute values of the output voltage and grid voltage match by 201)
A pulse output section 71)≦two-pulse width control signal is output from t20+, and a pulse width control signal is output from the pulse output section t211 to the inverter (2
) is controlled, and the output voltage of the inverter (2) is controlled so that the absolute values of the output voltage and the grid voltage become equal, and at the same time, the first . 2' Tortoise pressure detection part (9), (detection signal from 101 or switch 9 concave part) is manually inputted to the phase comparator signal from 1st phase comparator 081 to inverter (2) to inverter system +3
A voltage phase comparison signal is output so that the phase of the output voltage of the first output voltage is synchronized with the phase of the commercial power grid (410) grid voltage,
iii'J from pulse output section - to inverter (2)
The pulse width of the pulse for aJ is controlled, and the impark f2
The phase of the output voltage 1 is controlled so that the phase of the output voltage is synchronized with the phase of the commercial power system Xjj''a pressure.

Next, when it is detected from the synchronization detection unit (1 stage 2) that the output voltage of the inverter system (3) and the grid voltage of the commercial power system (4) are synchronized in phase, the synchronization detection unit α■ to the CP
A synchronization signal is output to U(RO, and the synchronization signal causes a
pU(2(j to status 9 Kusui 9chi drive unit
The control signal is output and the study switch (8
) is turned on, and in addition to the power from the commercial power grid (4), [
When the power of the inverter system (3) is supplied to the load (5), the power of the inverter system (3) is
5) is controlled so as not to exceed the total W6 power requirement. At this time, negative current lL&''J is supplied from the commercial power system (4) (3
(See figure (A)).

The phase shift circuit (to) is composed of, for example, a counter, etc., and can advance or delay the phase of the input signal by one step depending on the pulse data value from the CPU (203). It is assumed that the brisset data value of the 4-phase circuit 3tli is light period time α, and that the phase synchronization state between the inverter output voltage ex and the system voltage aC is maintained.Next, the CPU (201 is the selection stage (-ChirJ
11, select C in-park output current 1 and load-flow. The phase detection circuit (G) receives signals corresponding to both DC currents, and detects the difference between the inverter output current I and the load current IL.
The phase of 4jl is determined by the delay and 10PU[2U
Send a digital signal to +. Here, the CPU αti determines that the impark output current 1 is delayed in phase from the load current 1L, and as shown in Figure 145, the inverter output's sieve pressure is increased by 61 and the system voltage is reduced by CΔO. The phase shift circuit (increases the data value β of 3i1 to α + β. At this time, the OP U f201 converts the inverter output current I and the magnitude of the shell current into a converter. 110? Read through 'L, inverter output DC I power size force 1 page load ridge treatment 1
The pulse width of the inverter (2) is fully controlled so that the size of L is less than 1 throughout the entire area. In this way, the CPU (2α is the signal C2 of the phase detection circuit) increases the preset data value of the C phase shift circuit by β increments to match the inverter output current A and the load current rise position f.J, UPIJ(,:α
At the same time, the inverter (
Since the pulse width of 2) is fully controlled, regeneration of the inverter output into the commercial power system (4) cannot occur.

Through all such control, the inverter output '+ti/
When the phase of JtEix and the negative current match, -CPU
(201 is the bidirectional switch shown above) selects the inverter output/r power ° 1 δ drift earthwork and the shell current 1 L, and at the same time inputs the phase shift circuit ( The criminal's Brise Misaki data 4M is never set to α to end the transition from the kick pressure position to the current phase synchronization state.

(f) Effects of the Invention As described above, the present invention connects a pulse width modulation inverter system using a solar cell as a power source and a commercial power system in parallel, and prevents the power supplied from the inverter system from exceeding the total power demand of the load. A power supply device that operates both systems to supply power to the load so that the load current and the output current of the inverter system are in phase synchronization between the voltage of the power system and the output voltage of the inverter system. means for controlling the pulse width of the output current of the inverter system so that the output current of the inverter system does not exceed the load current in the process of transitioning from the voltage phase synchronization state to the voltage phase synchronization state. When transitioning to current phase synchronization state, ! While maintaining voltage synchronization, the voltage phase is gradually shifted to match the current phase k. At the same time, control is performed to prevent the inverter output current from exceeding the load current. There is no regeneration of solar energy, and solar energy can be used effectively.

[Brief explanation of the drawing]

Figure 1 is a general circuit diagram of a power supply device using parallel operation f2 - Figure 2 is a conventional circuit diagram for part ■ in Figure 1, and Figure 3 (M, (B) (0) is a vector diagram for explaining the circuit operation of FIG. 2 - FIG. 4 is a block diagram of an embodiment of the present invention for FIG.
This figure is a vector diagram for explaining the circuit operation of FIG. 4. (1)... Solar cell - (3)... Inverter system,
(4)...Commercial power system, (5)...Load, (6
f)...Output voltage, (ea)...System voltage, (i
engineering)...Output current + (it,)...Load current. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] il+ A pulse width modulation inverter system used as a solar power a'e power source and a commercial power system are connected in parallel, and both systems are connected in parallel so that the power supplied by the inverter system does not exceed the total power demand of the load. A power supply device that operates to supply power to the load, wherein the load current and n
Means for controlling the pulse width of the output current of the inverter system so that the output current of the inverter system does not exceed g+1 times the current in the process of transitioning to a state of phase synchronization with the output current of the inverter system described in IJ. A power supply device comprising: