CN104767466A - A starter generator system with automatic switching of windings - Google Patents

Abstract

The invention provides a starting power generation system capable of achieving automatic winding switching. The starting power generation system capable of achieving automatic winding switching comprises a three-phase motor with a tag in the middle, a three-phase inverter, a three-phase rectifier bridge and an electromagnetic switch. When the system is used for starting an engine, the electromagnetic switch enables the tail end of a three-phase winding to be in a short circuit state, a first part winding A1 and a second part coil A2 of the A-phase winding are connected in series, the number of windings is large, and the starting torque is large; when the system is used in the engine, the electromagnetic switch is switched off, the first part winding of the three-phase winding is connected to three H-bridge rectifiers, the number of windings is small, and the system is suitable for high-speed running during power generation. The technology of the starting power generation system capable of achieving automatic winding switching is very suitable for low rotation speed starting and high rotation speed running during power generation.

Description

A starter generator system with automatic switching of windings

technical field

The invention relates to a starting power generation system with automatic switching of windings, which belongs to the technical field of automobile electric appliances.

Background technique

The cranking system of a car can operate both as an electric motor and as a generator to supply power to electrical equipment after starting or to recover braking energy after driving the car.

In the existing literature, permanent magnet synchronous motors, permanent magnet brushless DC motors and electric excitation synchronous motors have been considered by many scholars as starter generators. Most of these motors use three-phase windings. Under the condition that the magnitude of the magnetic field remains constant, its induced electromotive force (or counter electromotive force) will be proportional to the rotational speed of the motor.

Taking a traditional gasoline engine as an example, the starting speed of the engine is about 200r/min, and the idle speed of the engine after starting is about 700r/min, and the normal speed after starting is above 1500r/min. The motor relies on the induced electromotive force (or counter electromotive force) for electromechanical energy conversion, and the induced electromotive force (or counter electromotive force) of the motor is different at different speeds, which cannot adapt to the constant voltage automotive power supply. Taking the 12V power supply system as an example, if the engine can achieve a back EMF of about 10V at about 200r/min, it will generate an induced electromotive force of about 100V at about 2000r/min, and an induced electromotive force of about 200V at 4000r/min, which will The 12V battery cannot be charged normally.

Therefore, it is very necessary to invent a starter generator system in which windings with different numbers of turns are used in the startup state and the power generation state, so that the starter generator can exert the best performance in both states.

In the existing technology, the authorized invention patent: ZL200780042653.4, a hybrid engine auxiliary system for vehicles, including a converter connected to the three-phase power terminals of the generator motor and the rotating machine through wiring, connected on the generator motor side In the case of the generator motor, the three-phase alternating current is converted into direct current, and in the case of being connected to the rotating machine side, the direct current of the battery is converted into three-phase alternating current and supplied to the rotating machine.

The inventor of the present invention also proposed to use two working modes of switched reluctance and double salient pole to switch between starting and power generation, and applied for an invention patent: a dual-mode motor generator, application number: 2014105380702.

The applicant has so far searched for a starter-generator technology that uses an inverter, a rectifier bridge and a double-contact electromagnetic switch to switch the number of winding turns to meet the requirements of the two working conditions of low-speed starting state and high-speed power generation state.

Contents of the invention

In order to invent a starting power generation system with automatic switching of windings to increase the output torque during low-speed starting operation and reduce the induced electromotive force during high-speed power generation operation, the present invention adopts the following technical solutions:

A starter generator system with automatic switching of windings, characterized in that:

Including three-phase motor, three-phase inverter, three-phase rectifier bridge, double-contact electromagnetic switch and controller;

There are taps in the middle of the three-phase armature windings of the three-phase motor, one end of the three-phase armature windings is respectively connected to the midpoints of the three bridge arms of the three-phase inverter, and the middle three taps of the three-phase armature windings Respectively connected to the midpoint of the three bridge arms of the three-phase rectifier bridge;

The ends of the three-phase armature windings are respectively connected to the three terminals of the double-contact electromagnetic switch, and the controller controls the closing or opening of the double-contact electromagnetic switch to connect or disconnect the ends of the three-phase armature windings. ;

The positive pole and the negative pole of the three-phase inverter and the three-phase rectifier bridge are respectively connected to the positive pole and the negative pole of the storage battery.

A starter generator system with automatic switching of windings as described above is characterized in that:

When the engine starts, the controller controls the double-contact electromagnetic switch to close, the ends of the three-phase armature windings are connected together, the controller controls the switching tubes on the three-phase inverter to turn on and off, and energizes the three-phase armature windings , the three-phase motor rotates and drives the engine to rotate;

When the engine starts, the three-phase motor is driven by the engine to rotate at a high speed, the controller controls the double-contact electromagnetic switch to be disconnected, and the end of the three-phase armature winding is suspended; the rectifier tube on the three-phase inverter and the rectifier bridge on the three-phase rectifier The rectifier tubes form three single-phase H-bridge rectifier circuits to rectify part of the coils of the three-phase winding, and the three-phase motor outputs direct current.

If the engine has been working at low speed for a long time after starting, the induced electromotive force generated by the coil between the three-phase rectifier bridge and the three-phase inverter is too low to ensure sufficient charging voltage, the controller will close the double-contact electromagnetic switch, and the three-phase motor will The ends of the three-phase windings are connected together, the three-phase motor is full-bridge rectified, and the output voltage is high.

The beneficial effects of the present invention are as follows:

(1) When starting, all the coils are involved in the work, and the starting torque is large. Due to the short starting time, the starter can withstand short-term overcurrent;

(2) When generating power, only part of the coils participate in the work, which solves the problem of magnetic field weakening and speed expansion during high-speed power generation operation, the internal resistance of the motor is small, and the efficiency of the motor is high.

Description of drawings

Fig. 1 is a schematic diagram of a starter generator system with automatic switching of windings according to the present invention.

Fig. 2 is a schematic diagram of a starting and generating system with automatic switching of windings in operation as a starter in the present invention.

Fig. 3 is a schematic diagram of a starting and generating system with automatic switching of windings in operation as a generator according to the present invention.

Fig. 4 is a schematic diagram of a starter generating system with automatic switching of windings during low-speed generating operation according to the present invention.

Detailed ways

The invention will be described in further detail below in conjunction with the accompanying drawings.

A starting power generation system with automatic switching of windings shown in Figure 1 includes a three-phase motor, a three-phase inverter, a three-phase rectifier bridge, a double-contact electromagnetic switch and a controller.

The three-phase armature winding of the three-phase motor has a tap in the middle, and the three-phase armature winding is divided into a part of the three-phase winding composed of coil A1, coil B1, and coil C1, and a part of the three-phase winding composed of coil A2, coil B2, and coil C2. The second part of the three-phase winding.

One end of the three-phase armature winding is respectively connected to the midpoints of the three bridge arms of the three-phase inverter, and the middle three taps of the three-phase armature winding are respectively connected to the midpoints of the three bridge arms of the three-phase rectifier bridge.

The ends of the three-phase armature windings are respectively connected to the three terminals of the double-contact electromagnetic switch, and the controller controls the closing or opening of the double-contact electromagnetic switch to connect or disconnect the ends of the three-phase armature windings. .

The positive pole and the negative pole of the three-phase inverter and the three-phase rectifier bridge are respectively connected to the positive pole and the negative pole of the storage battery.

When tapping from a three-phase winding, the position of the tap can be found in the same slot according to different turn ratios, or the position of the tap can be found according to different slots in the distributed winding. In addition, the ratio before and after the winding tap can be reasonably selected according to the comparison of the speed regulation range.

A starting power generation system with automatic switching of windings shown in Figure 2 operates as a starter, the controller controls the closing of the double-contact switch, the ends of the three-phase armature windings are connected together, and the controller controls the three-phase inverter The switch tube is turned on and off to energize the three-phase armature winding, and the three-phase motor rotates and drives the engine to rotate.

As shown in Figure 3, a starting power generation system with automatic switching of windings, when operating as a generator, the three-phase motor is driven by the engine to rotate at high speed, the controller controls the double-contact switch to be disconnected, and the switching tubes on the three-phase inverter are also turned off. Fully closed, the end of the three-phase armature winding is suspended; the rectifier tube on the three-phase inverter and the rectifier tube on the three-phase rectifier bridge form three single-phase H-bridge rectifier circuits, which rectify part of the coils of the three-phase winding, The three-phase motor outputs direct current.

Fig. 4 is a schematic diagram of a starter generating system with automatic switching of windings during low-speed generating operation according to the present invention. If the engine has been working at low speed for a long time after starting, the induced electromotive force generated by the coil between the three-phase rectifier bridge and the three-phase inverter is too low to ensure sufficient charging voltage, the controller will close the double-contact electromagnetic switch, and the three-phase motor will The ends of the three-phase windings of the three-phase motor are connected together. In the three-phase motor, coil A1 and coil A2 are connected in series, coil B1 and coil B2 are connected in series, and coil C2 and coil C1 are connected in series. when the charging voltage.

The working principle of the starter generator system proposed by the present invention will be described below.

When the starter generator of the present invention is working in the generating state, the armature winding has a flux linkage passing through. When the outer rotor rotates, the flux linkage of the armature winding coupling changes, so the flux linkage of the armature winding changes, thereby generating an induced electromotive force. Since the center taps of the three-phase armature windings are shorted together at this time, the induced electromotive force generated by the armature coil A1, armature coil B1 and armature coil C1 passes through the diode on the first inverter and the three-phase rectifier bridge The diode is rectified and output to the outside world. The armature coil A2, the armature coil B2 and the armature coil C2 are suspended in the air, so no current is output to the outside. Assume that the number of turns of the armature coil A1 is half of the total number of turns of phase A, so compared with the traditional solution, its output voltage is also reduced by half.

When the starter generator of the present invention is working in the starting state, if a forward current is passed to the one-phase winding with increased flux linkage, and a reverse current is passed to the one-phase winding with reduced flux linkage, the motor will generate positive torque. , driving the engine to rotate. In the starting state, because the ends of the three-phase armature windings are cleverly shorted together by the double-contact electromagnetic switch, the armature coil A1 and the armature coil A2 are connected in series, that is, all the coils will be energized, and the output torque big.

Since the starting speed of the engine is 200r/min, and the engine speed will rise above 700r/min after starting, the engine has an acceleration process during this period. During this process, the starter generator is only idling and does not output current. The double contact switch is closed without large electric sparks and voltage fluctuations.

As the saying goes, the best is the simplest. The simpler the technology, the more practical it is, because simple things have high reliability and low cost. Although the technology of the present invention seems simple, it has indeed been obtained after a lot of thinking.

It should be pointed out that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of All changes and replacements should fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (2)

1. a starting-generating system for winding automatic switchover, is characterized in that:

Comprise three phase electric machine, three-phase inverter, three-phase commutation bridge, double-contact electromagnetic switch and controller;

With tap in the middle of the threephase armature winding of described three phase electric machine, one end of threephase armature winding is connected on the mid point of three brachium pontis of three-phase inverter respectively, and three, the centre tap of threephase armature winding is connected on the mid point of three brachium pontis of three-phase commutation bridge respectively;

The end of threephase armature winding is connected on three binding posts of double-contact electromagnetic switch respectively, and controller controls double-contact electromagnetic switch and closes or disconnect, to be connected together by the end of threephase armature winding or to disconnect;

On the positive pole that the positive pole of three-phase inverter and three-phase commutation bridge and negative pole are connected on storage battery respectively and negative pole.

2. the starting-generating system of a kind of winding automatic switchover as claimed in claim 1, is characterized in that:

When the engine is started, controller controls double-contact electromagnetic switch and closes, and the end of threephase armature winding is connected together, the switching tube conducting on controller control three-phase inverter and closedown, to the energising of threephase armature winding, three phase electric machine rotates and drives engine rotation;

When after engine start, three phase electric machine is by driven by engine High Rotation Speed, and controller controls double-contact electromagnetic switch and disconnects, and the end of threephase armature winding is unsettled; Rectifying tube on three-phase inverter and the rectifying tube on three-phase commutation bridge form three single-phase H bridge rectification circuits, carry out rectification to a part of coil of three-phase windings, and described three phase electric machine exports direct current;

If be in tick-over for a long time after engine start, the induced electromotive force that coil between three-phase commutation bridge and three-phase inverter produces is too low, enough charging voltages can not be ensured, double-contact electromagnetic switch closes by controller, the end of the three-phase windings of three phase electric machine links together, three phase electric machine is full-bridge rectification, and output voltage is high.