Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
  • G05F1/00—Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
  • G05F1/66—Regulating electric power
  • G05F1/67—Regulating electric power to the maximum power available from a generator, e.g. from solar cell
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal

Definitions

• the object of the invention is a method for receiving electrical power generated by the generator, generating alternating voltage and a system for implementing the method applicable for example in:
• a Japanese patent JP2005072546 discloses the lamps which use a light emitting diode LED as a light source provided with a power source, wherein the output of the dynamo is rectified and has a voltage processing element, such as a DC/DC converter and the like, preferable in terms of productivity.
• the lamp has an element for load control, which directly or indirectly detects the output power of the generator and properly controls the load level.
• the control element detects the output power of the generator, for example, in the form of voltage, and based on this information, controls the load in such a way that it changes the corresponding number of operating LEDs or load current etc.
• LEDs other than light sources may be used as a voltage detection element or a microcomputer or the like may be used for direct and indirect power detection and control.
• a German document DE102009043911 discloses a method which comprises measurement of the voltage generated by the generator and the transmission of the measured voltage values to the control circuit.
• Control value for the AC voltage switch is calculated in the controller circuit based on this voltage value.
• the current generated by the generator is converted to a current supplying energy electronic system in a function of the control value.
• a separate control value for the energy electronic system is calculated by the voltage value.
• CN101793235A described a system which relates to a device for tracking the maximum power of the wind generator of the predictive power and is equipped e.g. with the detector of current and the rotational speed of the generator, wind speed and output bus voltage, and uses this data to adjust the inclination of rotor lobes, obtaining unitary power factor and track maximum power point of the generator.
• Polish application P.397131 discloses also a dynamo power control system consisting of an dynamo overload detector, frequency meter of the current generated by the dynamo, a processor controlling power distribution and the converter.
• the overload detector is built with an operational amplifier in a comparator system that detects the voltage drop on the dynamo, and invokes interruption at the processor port.
• the proposed solution allows for a unique use of the DC converter feedback to detect the state of the generator, i.e. to determine the location of its operating point relative to the maximum power point. This allows intelligent power take-off, always close to the maximum possible under the circumstances without having to install additional sensors and measuring devices on the generator, regardless of the current rotational speed of the generator.
• the location of the operating point of the generator relative to its maximum power point does not require measurement of the power generated by the generator or supplied to the receivers, but only determining and monitoring the frequency of the generator voltage and the output voltage of the rectifier, i.e. at the input of the converter.
• Applied solution is flexible and allows to supply any receivers, without e.g. dividing them into groups, which are then turned on or off, and without the knowledge of the parameters and electrical characteristics (power, current, voltage) of these receivers.
• applied solution allows more accurate (than in the case of dividing receivers into groups) power control, so that the maximum power point is achieved with greater accuracy.
• Applied solution does not require to control the AC voltage converter (rectifier), and only the constant voltage converter (DC converter).
• the solution does not require the construction of a complete control system, since it is possible to use a standard converter controller supplemented with additional elements.
• the controller of a typical converter performs the output voltage regulation U ou t a a preset level, regardless of current l out , with which the receivers load the converter and regardless of the input voltage Uj n .
• the rectifier converts AC voltage U geri into DC voltage Ui n .
• Voltage U in is an increasing function of the generator voltage U gen ; while the generator current l gen is an increasing function of current l m . Assuming that there is no power loss in the rectifier, the converter input power Pj n is equal to the generator power
• the controller of the converter will try to compensate for this decrease by extending the conduction time of the transistor converter. Based on the properties of the converter it can be concluded that at the desired value l out ⁇ the input current lj n is an increasing function of this time. Thereby the current loading the generator l gen will increase even more. According to Fig. 1 , this will lead to a further decrease of power Pgen- According to the reasoning carried out above, consequently U ou t voltage will decrease even more, which will result in a further prolongation of the conduction of transistor by the converter's controller, further increase of current lg eni decrease of P gen power and so on.
• both of these objectives can be achieved by stopping the generation of the controlling course of the converter's transistor.
• the transistor is then permanently open. Because it is connected in series between the input and output of the converter, its opening causes a decrease in the input current l, n to zero, and as a consequence also a decrease of the generator current l gen to zero.
• forcing constantly zero conduction time means the elimination of the above-described feedback, previously acting as the elongation direction of the time.
• a method for receiving power generated by the generator, generating AC voltage in the system comprising DC converter, incorporation of the converter into a power supply of a size adjusted to the power of the receiver, monitoring of the generator speed and tracking of the maximum power point of the generator in the feedback loop implemented in the electronic system is characterized in that the feedback is realized inside the converter so that the converter input registers the voltage change as the difference between the actual voltage and the last threshold voltage.
• the converter controller is temporarily deactivated, and then after the system has stabilized, the converter controller is reactivated if the generator frequency is increased and/or the power consumption increased from the generator. Then the converter controller is reduced to a specified value preferably for the output of the generator from the overload condition, and then the converter controller is loaded until the voltage drop again. Feedback loops are repeated.
• the converter is loaded with gradually increased current.
• deactivation of the converter controller is realized through stopping the generation of the transistor control signal
• load restoration takes place gradually with permanent or non- permanent steps.
• detection of the voltage drop used to detect the generator overload is carried out continuously.
• a controller contained in the DC converter further comprises a voltage measurement circuit which measures the output voltage of the rectifier, while a low-pass filter included in the rectifier has no effect on the input voltage ripple of the converter with a generator frequency, wherein a controller contained in the DC converter performs the function of maximizing the power factor of the generator output by direct or indirect formation of the input current of the converter according to the shape of the converter input voltage.
• the rectifier is a bridge rectifier, while in the DC converter controller system a zero detector and first comparator is connected to the microcontroller on one side and a second comparator on the other side.
• the second comparator is connected to the maximum connected to the standard controller and the voltage divider.
• a current sensor system connected to the second comparator and the voltage divider comprises a shunt and a low-pass amplifier.
• the second comparator is replaced with a subtracting amplifier, while a maximum is replaced with an adder.
• the method is based on the use of specific properties of the system comprising the generator, the rectifier and the DC converter. If the load current of the converter exceeds the value corresponding to the maximum power of the generator, then in a short time, the input voltage of the converter spontaneously drops to a low value. Detection of this voltage drop is thus identical with the detection of exceeding the maximum power point of the generator.
• Loading the converter with a current smaller than the value overloading the generator can therefore bring the system to the operating point close to the point of maximum power of the generator.
• the method of the invention does not require knowledge of the characteristics of the generator or the current measurement, but only the detection of the input voltage drop to a low value.
• the load current for which there is a maximum power of the generator increases with the rotational speed of the generator. In order to use the maximum possible power, it is necessary to monitor the rotational speed. If its increase is detected, the load current shall be increased again until the overload is detected, and then restore it to a lower value, in the manner described above.
• the voltage drop detection (point 4, 8 and 1) may be carried out continuously, asynchronously with respect to the other points of the algorithm.
• fig. shows characteristics of the generator according to the invention
• fig. 2 shows a block diagram of a complete system enabling the use of the described method
• fig. 3 shows a block diagram of an example system implementing the method according to the invention
• fig. 4 shows a block diagram of an example system implementing the method according to the invention, wherein the maximum and the second comparator were replaced by the adder and subtracting amplifier.
• rectifier P - an energy electronic system converting the alternating bipolar voltage into unipolar voltage which may further comprise a low-pass filter, reducing ripple of the input voltage of the converter PST;
• controller S - an energy electronic system performing the following functions: adjustment of the output voltage, limitation of output current, or stopping the generation of the control signal;
• the signals appearing in fig. 2 include:
• AC side voltage of the rectifier P u a e.g. a potential of one end of an AC diagonal of a bridge rectifier
• the output system includes functional blocks 1 and 4, the described solution requires the addition of block 2 and 3.
• Some elements of blocks 2 and 3 may appear in the output system subject to the availability of electrical signals mentioned above; complementing range is then reduced accordingly. It is also possible to integrate some sub-blocks of block 3 with each other (e.g. power circuit elements OM with the controller S) under the same condition.
• Fig. 3 shows a block diagram of an example system implementing the described method.
• a ratifier has the form of a bridge MP, while a DC converter PPS has a buck topology (buck).
• buck buck topology
• a current sensor CP consists of the following sub-blocks:
• shunt BP - a iow-value resistor includes in series with the converter output
• a low-pass amplifier WD - a system amplifying the DC component voltage and damping the components of ⁇ the switching frequency of the converter and higher.
• a controller S consists of the following sub-blocks:
• SS - a standard controller SS - a typical DC converter controller (e.g. in the form of a dedicated IC), with the feedback input designed to connect the centre point of the voltage divider connected to the output voltage of the converter;
• comparator K1 - a system comparing the input voltage of the converter u m with a specific threshold value
• microcontroller MK - a microprocessor generating a current reference signal (voltage) I ref , representing a nominal value of the converter output current;
• a standard controller SS generates a standard signal with a transistor (or transistors) located in the power circuit OM, so as to adjust the feedback voltage Ufb in the converter PPS at the specified reference value.
• the voltage divider DN produces the primary feedback signal Ufbi , associated with the output voltage of the converter PPS u out .
• a microcontroller MK produces a current reference signal l ref , which is compared by the second comparator K2 with the result of the converter PPS output current i ou t-
• the standard controller adjusts the voltage u ou t at a preset level, determined by the reference value and divider partition coefficient.
• the comparator K2 issues the voltage u 2 approximately equal to the internal supply voltage of the controller S.
• the high amplification of the standard controller SS causes issuing zero control signal for the power circuit OM, i.e. stopping generation of this signal. With buck topology this will interrupt the flow of current in the power circuit OM.
• the output current is limited to the setpoint, represented by a signal i ref .
• Measuring the rotational speed of the generator G and the detection of its increase is performed by the microcontroller MK by measuring the voltage frequency of the generator G based on the signal from the zero crossing detector D.
• the subtracting amplifier WO - an energy electronic system producing a feedback voltage u3 ⁇ 42 as the difference signal from the current sensor ⁇ QU t and the reference value Iref, possibly multiplied by a constant factor;
• the adder SM - an energy electronic system producing a feedback voltage u3 ⁇ 4 as the sum of the voltage u3 ⁇ 4i and voltage u3 ⁇ 42, possibly multiplied by a constant factor.
• the converter's PPS controller S may also be deactivated not through the maximum M block and feedback voltage input but by a direct connection of the second comparator K2 with the enable input (Enable) of the standard controller SS
• This solution may be a solution modification of fig. 3, in terms of both leaving the overloading condition, and adjusting the load current.
• the maximum power from the AC voltage generators it is important not only to match the average received power value with the generator, i.e. constant output current of the converter, but also appropriate adjustment of the instantaneous received power value, i.e. an alternating current drawn from the generator by the rectifier, in a way maximizing the power factor value at the output of the generator.
• This function can be implemented e.g. by including the capacitors of the same capacity at the input of the bridge rectifier, in order to select the capacity of these capacitors this capacity must be increased experimentally or by simulation ranging from zero, whilst measuring the power received from the generator; based on this, the capacity for which the power received from the generator is a maximum should be selected.
• Received power is increased to the highest ratio at standard conditions, i.e. for the rotational speed and load, for which the selection of capacitors capacity was performed. In contrast, when moving away from nominal conditions or in the event of changing the generator, this ratio will decrease.
• the same effect can also be achieved by way of the capacitors included in other sections of the system between the generator and the input of the converter or of the capacitors and the coils included between the generator and the input of the converter.
• passive PFC passive power factor correction
• active PFC active power factor correction circuits

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Automation & Control Theory (AREA)
• Control Of Eletrric Generators (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=59337807

Family Applications (1)

Country Status (4)

Family Cites Families (7)

• 2016
  • 2016-05-25 PL PL417341A patent/PL417341A1/pl unknown
• 2017
  • 2017-05-24 EP EP17739715.5A patent/EP3539209A1/de not_active Withdrawn
  • 2017-05-24 CN CN201780039964.9A patent/CN109565253A/zh active Pending
  • 2017-05-24 WO PCT/PL2017/000056 patent/WO2017204668A1/en unknown

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