JPH048122A - Dc power distribution equipment - Google Patents

Abstract

PURPOSE:To suppress the peak value of electric energy consumption by a method wherein a commercial power supply and a private power supply with power rectifiers are connected in parallel and a DC power is supplied to loads. CONSTITUTION:A power rectifier 21 which converts a commercial power supply 11 into a DC power supply and a power rectifier 22 which converts an AC private power supply 12 into a DC power supply are connected in parallel and DC distribution system loads 83-85 are connected to the power rectifiers 21 and 22. AC system loads 81 and 82 are directly connected to the commercial power supply 11 side. An inverter 71 is provided to convert DC into AC again and a D/D converter 72 is provided to convert the DC system voltage into a required DC voltage. The power rectifier 21 connected to the commercial power supply 11 is subjected to constant voltage control with current minus control while the predetermined value of the power rectifier 21 is so controlled as to have the power of the private power supply 12 side constant by a control circuit 3. With this constitution, economical power management can be realized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a DC power distribution system for supplying DC power to a load group by connecting a commercial power source via a forward converter and a private power source in parallel. Regarding equipment.

[Conventional technology]

Recently, with the remarkable development of electronics technology,
Electronics application equipment or OA in load equipment
The proportion of equipment, etc. has increased significantly.

At present, most of the power sources used in such applied equipment use commercial AC power, which is converted to DC using an internal rectifier.

On the other hand, private power generation sources are becoming more diverse, and direct current type private power generation sources such as fuel cells and solar cells are also emerging.

[Problem to be solved by the invention]

Under these circumstances, it is fully predicted that in the future, part of the power distribution equipment within each customer will be converted to direct current.

Therefore, an object of the present invention is to provide such a power distribution facility for the future.

[Means to solve the problem]

A forward converter connected to a commercial power source and a forward converter connected to an AC private power source are connected in parallel to supply DC power to the load group, and the set value is set so that the private power generation becomes a predetermined value. or, when the total amount of power of the load exceeds a predetermined value, select the forward converter on the commercial power side to supply that amount from the private power generation side. Control by changing set values. Furthermore, even if the private power source is a DC power source, it is connected in parallel with the commercial power source to perform the same control as above.

[Effect]

DC power distribution is made possible by connecting a commercial power source and an AC private power source in parallel via a forward converter, and when the power consumption is higher than a predetermined value, the private power source generates the same amount of power. By supplying electricity, the amount of contracted electricity can be reduced. In other words, since the contract amount of power is determined by the peak value of the amount of power used, economy is achieved by lowering that peak value. Furthermore, even when the private power source is a DC power source, it is connected in parallel with the commercial power source and the same control as above is performed to obtain the same effect.

〔Example〕

FIG. 1 is a block diagram showing a first embodiment of the present invention in which the private power source is an alternating current, in which 11 is a commercial power source, 12 is a commercial power source;
is a private power source, 21.22 is a forward converter, 3 is a control circuit, 4 is a power regulator (APR), and 51 is a power detector (W)
, 71 is an inverter, 72 is a direct current/direct current (D/D) converter, and 81 to 85 are loads.

A forward converter 21 that converts the commercial power source 11 to DC and a forward converter 22 that converts the AC private power source 12 to DC are connected in parallel as shown in the figure, and the load 83 of the DC distribution system is connected here.
85 are connected, while AC loads 81 and 82 are directly connected to the commercial power source 11 side. Note that the inverter 71 is provided to convert direct current back into alternating current, and the D/D converter 72 is provided to convert direct current to a predetermined direct current voltage. The forward converter 21 connected to the commercial power source 11 is subjected to constant voltage control with minor current control by the control circuit 3 while taking into account its set value so that the power on the private power generation source 12 side is constant. Therefore, the power detector 51 detects the power of 12 private power generation sources and converts it to APR4.
control is carried out by adjusting the voltage setting value in the control circuit 3. Therefore, the electric power of the 12 private power generation sources becomes a constant value.

FIG. 2 is a block diagram showing a second embodiment of the invention.

In FIG. 2, elements having the same functions as those in FIG. 1 are given the same reference numerals. In this FIG. 2, numeral 52 is a power amount detector (WH>), and is configured so that the detected value is taken into the APR4.

Incidentally, the load varies depending on the time of day, and in some cases it may greatly exceed the normal value as shown in FIG. 3(a), but it is economically disadvantageous to conclude a power contract accordingly. Therefore, in this case, it is recommended to lower the set voltage value of the forward converter 21 than usual so that the amount of electricity exceeding the contracted amount is supplied from the private power source 12 as shown in Fig. 3 (b). For example, electricity contracts can be made cheaper.

Here, this kind of control is called peak cut control.
When a power detector (WH) 52 that monitors the total power of the load detects that the total power of the load exceeds a predetermined value, peak cut control is performed.

FIG. 4 is a block diagram showing a third embodiment of the invention. In this embodiment, selection switches 61 and 62 are provided, and the first
The constant power control explained in the figure and the peak cut control shown in FIG. 2 can be used together by switching the switches 61 and 62.

The above description is for the case where the private power source is AC, but the present invention can be applied in the same manner as above when the private power source is DC.

FIG. 5 is a block diagram showing an embodiment in such a case.

This corresponds to the previous Fig. 1, and the DC power from the DC private power generation source 12 consisting of a fuel cell, for example, is supplied to the grid via the block diode 23, and the rest is the same as Fig. 1. Therefore, the details will be omitted. Note that the block diode 23 is provided to prevent backflow.

FIG. 6 corresponds to the previous FIG. 2, and FIG. 7 corresponds to the previous FIG. The features are the same as in Figure 2 or Figure 4, so
Details are omitted.

[Effects of the Invention] According to this invention, a commercial power source and a private power generation source via a forward converter are connected in parallel to supply DC power to a load, so that a large number of electronic devices, OA devices, etc. It is suitable for the system that requires it. Moreover, if peak cut control is performed, there is an advantage that economical power operation becomes possible.

Furthermore, in a cogeneration system that pursues economic efficiency by effectively utilizing energy, it is usually desirable to operate with constant power, so by controlling the load capacity of the private power source at a constant constant, It can be effectively applied to other systems.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a first embodiment of the present invention when the private power source is AC, and Fig. 2 is a block diagram showing a second embodiment of the invention when the private power source is AC. Figure 3 is an explanatory diagram for explaining the operation of Figure 2.
The figure is a block diagram showing a third embodiment of the present invention when the private power source is an alternating current, and FIG. 5 is a block diagram showing the first embodiment of the present invention when the private power source is a direct current. Figure 6 shows the second example of this invention when the private power source is direct current.
Block Diagram Showing Embodiment FIG. 7 is a block diagram showing a third embodiment of the present invention when the private power source is direct current. Code explanation 11...Commercial power source, 12...Private power source, 21
゜22... Forward converter, 23... Block diode, 3... Control circuit, 4... Power regulator (APR)
, 51...Power detector (W), 52...Power amount detector (WH), 61.62...Switch, 71...
Inverter, 72...D/D converter, 81-85
···load.

Claims (1)

[Claims] 1) A forward converter connected to a commercial power source and a forward converter connected to an AC in-house power source are connected in parallel to supply DC power to a load group, and the in-house power is generated at a predetermined level. DC power distribution equipment characterized by controlling a commercial power side forward converter by selecting a set value so that the same value is achieved. 2) A forward converter connected to a commercial power source and a forward converter connected to an AC private power generation source are connected in parallel to enable supply of DC power to a load group, and to ensure that the total electric power of the load exceeds a predetermined value. 1. A DC power distribution facility characterized in that when the amount of power generated is increased, the set value of the forward converter on the commercial power side is changed and controlled so as to supply that amount from the private power generation side. 3) Connect a commercial power source via a forward converter in parallel with a private DC power generation source to supply DC power to the load group, and select a setting value so that the private power generation power reaches a predetermined value, and then DC power distribution equipment characterized by controlling a power side forward converter. 4) Connect a commercial power source via a forward converter in parallel with a private DC power source to supply DC power to the load group, and when the total power of the load exceeds a predetermined value, A DC power distribution facility characterized in that control is performed by changing a setting value of the forward converter on the commercial power side so as to supply that amount from the private power generation side.