Canon Kabushiki Kaisha

Seiji Kurokami

Nobuyoshi Takehara

Naoki Manabe

Kimitoshi Fukae

Hiroshi Kondo

Masaki Suzui

Akiharu Takabayashi

Yoshitaka Nagao

Manabu Nakanishi

An electric power control apparatus outputs output from a power generation apparatus to a power system has a power converter that converts power output from the power generation apparatus and a power storage apparatus that stores output from the power generation apparatus or output from the power converter as well as discharges stored electric power as necessary detects an amount of electric power generated at the power generation apparatus within a predetermined time period, sets an output pattern of the electric power control apparatus in a next predetermined time period based on the amount of electric power of each predetermined time period, and controls the output of the electric power control apparatus in accordance with the output pattern. By so doing, for example, even where the output from the power generation apparatus fluctuates, the amount of electric power output to the power system is decided in advance, and electric power equivalent to the difference between the predetermined amount and the output amount is stored in a power storage apparatus or discharged from the power storage apparatus.

Electric power control apparatus, power generation system and power grid system

In a power generation system of this invention, the outputs from power generation layers electrically connected in series are input to corresponding power conversion devices, and boosted outputs are connected in parallel and fed to a load. Alternatively, the output from one of power generation layers electrically connected in series is input to a first power conversion device, and the serial output and the boosted output from the first power conversion device are connected in parallel, input to a second power conversion device, boosted, and fed to the load. Since the two power generation layers can be individually output-controlled, each power generation layer can be optimized basically without considering current balance. Since the optical spectrum utilization efficiency increases, the power generation efficiency increases. In addition, since the power can be fed not to separate loads but to one load, the convenience largely increases.

Power generation system and power generation apparatus

The object is to reliably detect a ground fault of a solar battery. To detect a ground fault position to take an efficient measure against the ground fault, DC power input from a solar battery is converted into AC power and supplied to a system. In a system interconnection inverter (utility connected inverter) having non-insulated input and output, the input voltage of a converter circuit and/or the intermediate voltage between the converter circuit and an inverter circuit are varied to control the potential to ground at each portion of the solar battery to a value other than a value close to zero.

Power converting apparatus, control method therefor, and solar power generation apparatus

Control means is provided, in which the whole of the phase difference of a power waveform of each phase is matched to a value dividing a cycle of the power waveform into n-equal portions, and at the same time, the whole of the power value of each phase is controlled to be identical, so that the power conversion unit having a n-alternating current output (n is an integer numeral serving as n&#x2267;2) connected to the direct current power source and smoothing means provided between the direct current power source and the power conversion unit are made small in capacity.

Power converter and power unit

In a power conversion system having a DC power supply which has an almost fixed DC voltage to ground and a predetermined stray capacitance to ground and outputs a DC power, and a power converter which converts the DC power output from the DC power supply into an AC power by switching, the phase of an AC voltage to ground generated in the DC power supply by switching is detected, the phase of an AC ground fault current that flows through the stray capacitance to ground and the ground fault resistance of the DC power supply is detected, and the difference between the two detected phases is compared with a predetermined threshold value, thereby determining a DC ground fault in the DC power supply. With this arrangement, the ground fault state of the DC power supply can more accurately be detected. In addition, the operation efficiency of the power conversion system can be increased.

Apparatus and method of detecting ground fault in power conversion system

AC module, integrating a solar battery and an inverter, can easily be connected with other plural AC modules in parallel by way of cascade connections. However, when the number of AC modules connected is improvidently increased, the current flowing through the current path or connector of the AC module exceeds a rated current. In view of this, the current detector detects a current in the collective-power current path of the AC module, and when the detected current value exceeds a value set in the reference current setting circuit, the current detector stops the inverter.

Solar battery module and power generation apparatus

In a solar power generation system having an inverter, if a smoothing capacitor in the inverter degrades, the operation of the inverter is interrupted, and a loss in the amount of power generation occurs inevitably. To prevent this loss, a degradation determination section ( ) and output suppressing section ( ) are provided in an inverter ( ). If the degradation determination section ( ) determines a degradation in capacitor ( ), the operation of the inverter ( ) is continued while suppressing the output current of the inverter ( ) by the output suppressing section ( ). In addition, a warning section ( ) warns the user about the degradation in capacitor ( ). With this arrangement, a solar power generation system capable of detecting a degradation in smoothing capacitor in the inverter ( ) and appropriately operating the inverter ( ) can be provided.

Power converting apparatus, control method therefor, and power generation system

In a power supply system for converting the output of a DC power supply having an earth capacitance to AC power, an input voltage from an input-voltage detector and an intermediate voltage from an intermediate-voltage detector are input to an input-ripple controller. The latter calculates the difference between ripple voltages of the two voltages. The input-ripple controller adjusts the size of a ripple command value, which indicates the ripple current that is to be input to a converter circuit, so as to null the difference between the ripple voltages. Furthermore, using a ripple reference waveform having a DC level, the input-ripple controller generates a ripple current waveform so as to null the average value of a full-wave rectified waveform synchronized to the output of an inverter circuit, and outputs the generated ripple current waveform to an output calculator. The output calculator adds the DC current command from the input-voltage controller and the ripple current waveform from the input ripple controller to thereby generate an output current waveform, which is output to a converter circuit driver.

Method of reducing leakage current in power supply systems

In a solar power generation apparatus using a solar battery having a relatively large ground capacitor and a power conditioner having a non-insulated input and output, a customer's ground fault interrupter may perform unwanted interruption due to a ground fault outside the customer's premises. To prevent this, when a ground fault is detected by a detector capable of detecting a ground fault within a shorter time than the customer's ground fault interrupter, the gate of inverter of the power conditioner is blocked, a switch is changed to an open state, and the input voltage of inverter is held at a voltage value higher than the peak value of the alternate current voltage of a power system until at least the switch changes to the open state.

Interconnection power converter and power generation apparatus using the same

To display the sum of power generation in a photovoltaic power generation system having a plurality of independently-operating inverters in real time, an information display device receives information indicative of amounts of power generation respectively outputted from the plurality of inverters, calculates the sum of power generation in the plural inverters based on the received information, and displays the result of calculation.

Information display apparatus, information relay apparatus used in power generation system, information display method and information relay method, and information transmission method

A solar cell array is constructed by connecting plural solar cell strings in parallel, and the solar cell array is arranged to have strings of two or more rated voltages. This arrangement permits the solar cell array to be designed so as to maximize the output capacity in an area where the solar cells can be installed. In addition, the arrangement has high degrees of freedom of design to enable to construct a preferred configuration in terms of the design. Further, the solar cell array can be provided in a device configuration of low cost. Also provided is an array constructing method to facilitate installation and wiring.

Solar cell array and solar power generation apparatus using it

A solar cell array used in a photovoltaic power generation apparatus for housing covers a relatively large outside area for installation, and a considerably large earth capacitance Ca exists between the solar cell array and the ground. Further, as an inverter for converting direct-current electric power generated by the solar cell array into alternating-current electric power, a transless-type inverter is used for reducing cost. Therefore, a slight leak current flows via the earth capacitance Ca, which may cause undesirable operation of an earth leakage circuit breaker inserted between the inverter and a commercial AC power system. In the photovoltaic power generation apparatus of the present invention, by designing it so that the relationship between the earth capacitance Ca[.mu.F] and leak current detection sensitivity EL[mA] of the earth leakage circuit breaker is Ca&lt;EL/3, the undesirable operation of the earth leakage circuit breaker due to the leak current is prevented.

Photovoltaic power generation apparatus

In order to accurately and stably measure the output characteristics of a battery power supply device, especially, a large-scale solar cell module by an equipment that requires only a size and cost equivalent to those of an apparatus used for measuring a small-scale module, the light-receiving surface of the solar cell module is divided into areas each including a bypass diode, the output characteristics upon light illumination in units of divided areas are measured, the measured characteristics are synthesized, and the influence of bypass diode characteristics is subtracted from the synthesized characteristics, thereby calculating the output characteristics of the solar cell module.

Battery power supply device characteristic measuring apparatus and

In a power control apparatus of a solar power generation system for converting power generated by a solar panel and supplying the converted power to a load, the output voltage and output current of the solar panel are sensed, and, under ordinary conditions, MPPT control is performed so that the solar cells will operate at a maximum output point. If the output power of the solar panel exceeds a predetermined power, a power conversion unit is controlled so as to raise the output voltage of the solar panel, thereby limiting the output power of the solar panel. As a result, excessive power is prevented from being output by the power control apparatus.

Growing community of inventors

Kyoto, Japan

Seiji Kurokami