RU2382900C1 - System for autonomous power supply of loads - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: invention is related to the field of electrical engineering and wind power engineering, namely to autonomous systems of power supply, providing high-quality electric energy to loads distanced from system of centralised power supply. Proposed system comprises wind power plant, which is connected to common busbars via rectifier, inverter, stabiliser, reverse current relay, accumulator battery, connected between rectifier and inverter, autonomous source of power supply, working on organic fuel, equipped with synchroniser and controller of generated power. At the same time, according to the present invention, unit of signal generation is connected to inlet and control circuits of inverter, and it generates signals of certain shape depending on pulsations and value of rectified voltage. System also comprises unit for control of power supply sources operation modes, including time relay, intermediate relay, current and voltage relay contacts. Stabiliser and relay of reverse current are installed downstream inverter, accumulator battery is connected to inverter via diode and is charged from double-staged charging device, which is connected to common busbars via contactor, which provides for high-quality charging. In circuits of autonomous power supply source, electric energy consumer and circuit of charge there are current relays installed, and downstream rectifier there is voltage relay connected, while accumulator battery and rectifier are connected to inverter via contactors. ^ EFFECT: expansion of wind power plant resources in generation of high-quality electric energy, provision of reliable power supply and saving of organic fuel by matching of power supply source sources operation modes, prolongation of accumulator battery service life. ^ 2 dwg

Description

The invention relates to wind energy, namely to autonomous power supply systems that provide consumers with high-quality electric energy, remote from the centralized power supply system.

Known autonomous wind power installation (wind turbine) (patent RU No. 2239722, 7 F03D 7/04, 7 F03D 9/00), in which the method of converting the electromotive force (EMF) of the battery (AB) is selected slightly lower than the rectified EMF of an uncontrolled rectifier in the maximum mode the speed of the wind wheel and the maximum excitation current of the generator, the regulation of the charge current is carried out using a step-up pulse DC-DC converter according to the law of maximum power taken from the wind wheel.

The disadvantages of this installation are the low reliability of power supply due to the cessation of power generation in the absence of wind, charging the battery with a pulsating voltage, the complete discharge of the battery and the termination of power supply to consumers in the long absence of wind.

A well-known autonomous uninterrupted power supply system using a renewable energy source (patent RU No. 2262790, 7 H02J 7/34, H02J 3/38, F03D 9/00), consisting of two independent power sources interconnected by a switching unit, the function of one of them performs a diesel generator set equipped with a system for automatic regulation of active power, the function of the other is a synchronous compensator with an acceleration device and an automatic speed control system, a wind turbine of variable rotation speed I, rigidly connected to a multi-speed asynchronous machine, controlled by a mode selection unit that sets its operating speed as a function of active power, AB connected to a synchronous compensator by means of a two-set reverse thyristor converter, which, when the wind turbine exceeds the load power, is controlled in a synchronous automatic stabilization system compensator, and in the mode when the wind turbine power is less than the load power and the battery is discharged, in the active m diesel generator set.

The disadvantages of the claimed autonomous system are high capital costs and energy losses (the system contains four electric machines), complex commissioning. To convert electricity, a thyristor converter is used, which is a generator of higher harmonics. The synchronous compensator idles in the absence of reactive power consumers.

In the application (RU No. 2004129674, F03D 1/06, F03D 9/02) an autonomous wind turbine is proposed in which at least two series-connected batteries are periodically disconnected from the battery during operation. Their total electromotive force is measured and the voltage of the generator is maintained at a nominal value by adjusting the output voltage of the controlled rectifier depending on the measurement results.

The disadvantages of the claimed invention are the use of controlled rectifier, the use of which limits the maximum power take-off from the generator and creates a very variable load on the shaft of the wind wheel; occurrence of additional power losses during smoothing of fluctuations of the rectified voltage, which vary depending on the wind speed; poor battery charge. At the output of the inverter, one can expect a voltage distorted in shape.

The closest in technical essence to the claimed system is a device for autonomous power supply to consumers (patent RU No. 2323251, F03D 9/00) containing a wind power installation and a synchronous generator driven by an internal combustion engine, a stabilizer is connected behind the wind power installation, between the rectifier and the autonomous the inverter has a rechargeable battery equipped with a charge controller, which is connected to the relay for starting the internal combustion engine and the control unit, to the wind ergeticheskoy installation connected heating element mounted in the storage tank, which receives energy from an unused user wind turbine, the device is provided with a power regulator thermal load autonomous control systems inverter and stabilizer.

The prototype has the following disadvantages.

1. When the wind speed decreases below the calculated one, not only the amplitude decreases, but also the voltage frequency generated by the generator. This leads to an increase in power losses and additional heating of the stabilizer core during its operation.

2. A change in the ripple coefficient of the rectified voltage causes errors in the operation of the stabilizer sensor, which affects the value of the stabilized voltage.

3. Battery charge rectified ripple voltage reduces its service life.

4. The inverter power supply with the rectified pulsating voltage leads to a distorted voltage form and, accordingly, low-quality electricity at its output.

The aim of the invention is to expand the capabilities of wind turbines in the generation of high-quality electric energy, ensuring the required reliability of power supply, reducing the consumption of fossil fuels by an autonomous power source (AIP), and increasing the battery life.

This goal is achieved by the fact that in a system for autonomous power supply containing wind turbines, batteries and AIPs, a wind turbine generator for power consumers connected to a common bus through a stabilizer, a reverse current relay, an uncontrolled rectifier, an inverter, connected to a common bus AIP equipped with a synchronizer and a power regulator operating on fossil fuels, an AB is connected to the inverter, which can operate either as an independent power source or in conjunction with a wind turbine; unlike the prototype, a signal conditioning unit (BFS) is connected to the control and input circuits of the inverter, which generates signals depending on the magnitude and ripple of the rectified voltage, which are supplied to the control input of the inverter to obtain a sinusoidal voltage at the inverter output. A power supply control unit (BUR) is connected to the battery to ensure the required reliability of power supply, which includes a time relay, an intermediate relay, contacts of the current and voltage relays. A stabilizer and a reverse current relay are installed behind the inverter to maintain a voltage of a given value at a standard frequency, which reduces power losses. The battery is connected to the inverter via a diode and is charged from a two-stage charger connected to common buses via a contactor, which ensures high-quality charging and prolongs its service life. A current relay is installed in the circuits of the autonomous power supply, the consumer of electricity and the charge circuit, and a voltage relay is connected behind the rectifier, the battery and the rectifier are connected to the inverter via contactors.

According to available information, the set of essential features characterizing the essence of the claimed invention, allowing to obtain a new positive effect - the generation of high-quality electric energy, ensuring the reliability of power supply and reducing the consumption of fossil fuels by coordinating the operating modes of power sources, extending the battery life is not known and should not be explicitly prior art, which allows us to conclude that the claimed invention meets the criteria of "novelty" and "inventive ur Wen. "

The invention is illustrated by drawings, which show a schematic diagram of a device (Fig. 1) and a diagram of the control of operating modes of a wind turbine, a battery and an AIP (Fig. 2).

The system (Fig. 1) includes a wind wheel 1 to which a synchronous generator 2 shaft is connected. Synchronous generator 2 is connected to common buses 13 through a rectifier 18, voltage relay (KV1) 11, contactor (KM3) 14, inverter 15, stabilizer 16, relay reverse current 17. BFS 20 and AB 7 are connected between the contactor (KM3) 14 and the inverter 15. A diode 6 and a contactor (KM1) 5 are installed in the circuit connecting the AB 7 to the inverter 15 5. Electricity consumer 21 is connected to the common buses 13, whose circuit a current relay (KA3) 19 is installed; AIP 3, in the circuit of which a current relay (KA1) 4 is installed; the charger 9, controlled by the contactor (KM2) 10. AB 7 is connected to the charger 9 through the current relay (KA2) 8, between the AB 7 and the diode 6 is connected BUR 12.

The control circuit modes of wind turbines, AIP 3 and AB 7 (figure 2) is powered by AB 7 and includes a coil contactor KM1, in the circuit of which are installed normally closed contacts KA1 and KT1; the coil of the intermediate relay KL1, in the circuit of which the contact KA2 is installed; contactor coil KM2, in the circuit of which contacts KA3 and KM 3 are connected in parallel; KMZ contactor coil, in the circuit of which contacts KM1 and KV1 are connected in parallel, and KT1 time relay coil, in the circuit of which contact KL1.2 is installed.

The above scheme allows to ensure reliable power supply, save fossil fuels and extend the life of the AB 7. The latter is achieved by the inadmissibility of a full discharge of the AB 7 and turning it on after full charge only when the AIP 3 is turned off.

A system for autonomous power supply to consumers works as follows.

1. Power supply to consumers from wind turbines.

At a sufficient wind speed, the generated voltage by the generator 2 is rectified and supplied to the relay coil (KV1) 11, which closes the coil circuit of the contactor KM 3 with its contact, to connect the rectifier 18 to the inverter 15 and the BPS 20. AB 7 is connected to the inverter through diode 6 and the contactor (KM1) 5, since the contacts KA1 and KT1 are closed in the circuit of the coil KM1.

When the rectified voltage of the generator 2 is higher than the voltage AB 7 and the diode 6 is closed, the inverter 15 and the BFS 20 receive power from the generator 2. The BFS 20 generates a signal of the necessary shape, which is fed to the control input of the inverter to generate a sinusoidal voltage at the output of the inverter to which the stabilizer is connected supporting a voltage of a given value on common buses 13. Electricity is supplied to consumers 21 and through a contactor (KM2) 10 to a charger 9 operating in the "constant charging" mode.

2. Power supply to consumers from wind turbines and batteries.

When the wind decreases, the rotational speed of the wind wheel 1 decreases and the voltage of the generator 2 decreases. At a certain voltage value, the diode 6 opens and power is supplied to the inverter 15 from the battery 7. In this case, the generator 2 is disconnected from the load, which allows the wind wheel 1 to increase the idling speed. Then the voltage of the generator 2 increases, the diode 6 closes, power is supplied from the wind turbine. During joint operation of the AB 7 with a wind turbine, it is gradually discharged to the load, while reducing its charge to the minimum acceptable value, the charger 9 will switch to the "full charge" mode. A current appears in the charge circuit of AB 7, the current relay (KA2) 8 is activated, closing the coil circuit of the intermediate relay KL1, which, by contact KL1.1, gives the command to start the AIP 3, and contact KL1.2 closes the coil circuit of the KT1 time relay. After start-up and synchronization, AIP 3 supplies power to common buses 13 and the flowing current triggers a current relay (KA1) 4, which opens its contact KA1 in the KM1 contactor circuit, which will cause the AB 7 to disconnect from inverter 15. If AIP 3 fails to start, the relay time KT1 after the lapse of time will de-energize the coil circuit of the contactor KM1 and disconnect the battery 7 from the inverter 15, which prevents the complete discharge of battery 7.

3. Power supply from AIP and wind turbines.

With sufficient speed, a wind turbine works in conjunction with AIP 3 to save fossil fuels. When the wind speed and the rectified voltage decrease below a predetermined value, the voltage relay disconnects the generator 2 from the inverter 15. The AIP 3 continues to work, and the reverse current relay does not allow the voltage from the AIP 3 to be supplied to the stabilizer 16.

After the AB 7 is fully charged, the charger goes into the “continuous charging” mode, the contact of the current relay KA2 opens the coil circuit of the intermediate relay, the contact of which de-energizes the coil of the KT1 time relay, which will close the contact KT1 in the coil circuit of the KM1 contactor, and AB 7 is ready to work. When idling, the AIP 3 is turned off by the command of the current relay (KA1) 4, which simultaneously supplies power to the coil KM1 and connects the AB 7 to the inverter 15.

To prevent self-discharge of AB 7 in the absence of wind and load, the contact of the voltage relay KV1 and the contact of the current relay KA3, installed in parallel in the coil circuit of the contactor (KM2) 10, open and the contactor (KM2) 10 disconnects the charger 9 from the common buses 13.

Thus, the described system for autonomous power supply to consumers allows consumers to be supplied with high-quality electric energy, to ensure reliable power supply to consumers and to reduce the consumption of AIP fossil fuel by coordinating the operating modes of power sources, and to extend the life of the batteries.

Claims (1)

A system for autonomous power supply to consumers, comprising a wind power installation connected through a stabilizer, a reverse current relay, a rectifier and an inverter to common buses of electric energy, a battery connected between a rectifier and an inverter, an autonomous power source equipped with a synchronizer and a regulator of generated power, connected to a common to buses, characterized in that a signal generating unit generating control signal is connected to the control and input circuit of the inverter In a certain form, the power supply operating mode control unit is connected to the battery, containing an intermediate relay and a time relay, working contacts of the current and voltage relays, a stabilizer and a reverse current relay are installed behind the inverter, the battery additionally contains a diode in the connection circuit with the inverter and is charging from a two-stage charger connected to common buses via a contactor, relays are installed in the circuits of an autonomous power source, an electric power consumer and a charge circuit current, and behind the rectifier - voltage relay, the battery and the rectifier are connected to the inverter through contactors.

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