RU117192U1 - DC CONTROL MOTOR CONTROL DEVICE - Google Patents

Abstract

A control device for a contactless DC motor, characterized in that it contains a power source, one output of which is connected to the input of the inverter, and its other output is connected to a current sensor, while the first output of the inverter is connected to a synchronous electric motor, on the shaft of which there is a load, and the second the output of the inverter is connected to the input of the comparator unit, the second input of the inverter is connected to the output of the driver unit, the input of which is connected to the output of the phase switching unit, the first input of which is connected to the output of the control unit, and two other inputs of the phase switching unit are connected to the first outputs of the braking rate master unit and an acceleration rate master unit, the second outputs of which are connected to two inputs of the control unit, and the third input of the control unit is connected to the output of the current regulator, the input of which is connected to the output of the current comparison circuit, the first input of which is connected to the output of the maximum current unit unit, the second input which is connected to in the output of the current sensor, and the third input of the current comparison circuit is connected to the output of the speed controller, the input of which is connected to the output of the speed comparison circuit, the first input of which is connected to the output of the comparator block, and the second input of the speed comparison circuit is connected to the output of the maximum speed control unit ...

Description

The utility model relates to the field of automated electric drive, namely to control systems and can be used when working in acceleration and braking modes, as well as in modes close to starting at low speeds until the engine stops completely.

A control device for a contactless DC motor is known (Patent RU 16210 and 1 IPC 7 G05B 11/01 op. 10.12.2000)

A control device for a non-contact DC motor containing an adjustable secondary power source, N pairs of power switches having a grounded output and connected to the positive terminal of an adjustable secondary power source having a grounded output and an input power terminal, where N is a natural number series and N≥3. The outputs of N pairs of power switches are the terminals for connecting to the N windings of a non-contact direct current motor having N windings. A control unit, a control pulse generation unit, a modulator, N inputs of which are inputs for connecting to N sensors of the position of the rotor of the DC motor, are introduced into the device. The control pulse generation block has K outputs, where K is a natural series of numbers and K> 2N, which are respectively connected to the modulator inputs. The first input of the control pulse generation unit is connected to the output of the modulator, the second, third, fourth, fifth inputs of the control pulse generation unit are respectively connected to the first, second, third, fourth inputs of the control unit, 2N outputs of the modulator are respectively connected to the inputs of N pairs of power keys. The control input of the regulated secondary power source is connected to the control output.

The disadvantage of this device is the low reliability of controlling a contactless DC motor due to the possibility of ripple torque and uneven rotation of the motor.

A known control system for a non-contact direct current motor (Patent RU 45213 U1 MPK 7 Н02Р 6/10). The control system of a non-contact DC motor contains a reference unit, three rotor position sensors connected to a speed estimation unit that is connected to a speed controller, a power source connected to an inverter, a three-phase non-contact DC motor connected to an inverter, a controller block containing a controller speeds, a current regulator, an adder and three differentiation units, in addition, two current sensors are introduced, which are in the first and second phases of a three-phase contactless motor constant current, two analog-to-digital converters, inverter control unit, galvanic isolation device. The reference unit is connected to the speed controller, and the output of the speed controller is connected to the first input of the current controller. The outputs of the analog-to-digital converters are simultaneously connected to the inputs of the current regulator, the first and second differentiation units and the inputs of the adder. The output of the adder is simultaneously connected to the third differentiation unit and the input of the current regulator. The outputs of the differentiation units are connected to the inputs of the current regulator. A pulse-width modulator is connected to an inverter control unit, to which rotor position sensors are connected. The inverter control unit is connected to the inverter through a galvanic isolation device. As a result, the surges and ripples of the phase currents are reduced, which allows to reduce the surges of the moment and increase the smoothness of rotation of the motor. The disadvantage of this system is the difficulty of tuning the control system due to the presence of a large (redundant) number of blocks: three rotor position sensors, three differentiation blocks, two current sensors, as well as the settings of analog-to-digital converters connected by their outputs to the inputs of the current regulators, the first and second differentiation blocks and inputs of the adder, the output of which is connected to the third differentiation block and the input of the current regulator, which can lead to oscillatory transients with an increased duration. In addition, this control system requires a large number of additional power supplies with galvanic isolation between them.

The closest in value is the device for controlling the fan operation mode (Patent RU 109582 U1 IPC G05D 13/00).

The control device of the fan operation mode, mainly based on a direct current DC motor, contains a power source, one output of which is connected to the inverter input, and the other output is connected to the current sensor. The first inverter output is connected to an electric fan including a synchronous electric machine integrated in the fan wheel, and the second inverter output is connected to the input of the comparator unit. The second input of the inverter is connected to the output of the driver. The driver input is connected to the output of the control unit, the inputs of which are connected to the output of the current regulator and the outputs of the performance comparison circuit and the pressure comparison circuit. The first inputs of the performance comparison circuit and the pressure comparison circuit are connected to the outputs of the current sensor and the speed sensor, and the second inputs of the performance comparison circuit and the pressure comparison circuit are connected to the outputs of the capacity generator and pressure generator. The inputs of the speed sensor and rotor position sensor are connected to the outputs of the electric fan. The input of the current controller is connected to the output of the current comparison circuit, the first input of which is connected to the output of the current sensor, and the second input is connected to the output of the speed controller. The input of the speed controller is connected to the output of the speed comparison circuit, one input of which is connected to the output of the speed control unit, and its other input is connected to the outputs of the speed sensor, rotor position sensor and the output of the comparator unit.

The disadvantage of this device is the complexity of the control device, determined by the redundancy of the control channels (control channel for performance and pressure) of the electric fan, which in turn leads to the presence of elements such as a setpoint for performance and pressure, as well as their comparison circuits, which in turn are connected by inputs with current and speed sensors, respectively. The increasing complexity of the functional relationships of these blocks makes it difficult to configure the control unit.

The objective of the utility model is to create a new control device for a contactless DC motor, which allows to increase labor productivity when it is used in the process of application with a large number of starts and brakes of the electric drive.

The technical result consists in reducing the time of accelerated acceleration and accelerated braking in the process flow diagram.

The technical result is achieved in that the control device of a contactless DC motor is characterized in that it contains a power source, one output of which is connected to the input of the inverter, and the other output is connected to a current sensor, while the first output of the inverter is connected to a synchronous motor on the shaft which is the load, and the second inverter output is connected to the input of the comparator unit, the second inverter input is connected to the output of the driver unit, the input of which is connected to the output of the switch unit phase, the first input of which is connected to the output of the control unit, and the other two inputs of the phase switching unit are connected to the first outputs of the accelerator ramp unit and the acceleration ramp unit, the second outputs of which are connected by two inputs of the control unit, and the third input of the control unit is connected to the output a current regulator, the input of which is connected to the output of the current comparison circuit, the first input of which is connected to the output of the overcurrent unit, the second input of which is connected to the output of the current sensor, the third input of the circuit sake of compari- son current connected to the output of the speed controller having an input coupled to an output of the comparison circuit speed, the first input coupled to an output comparator block and a second input of the speed comparison circuit is connected to the output of the maximum speed set point.

New is the presence of new blocks and new connections between the blocks, with a significant reduction in the number of blocks (relative to the prototype) and the simplicity of tuning the entire control system of a contactless DC motor.

The simplification of the control device for a contactless DC motor is achieved by reducing the number of blocks, namely: the lack of rotor position sensors, speed sensors, comparison circuits for performance and pressure, setpoints for performance and setpoints for pressure.

The rapid transition of the engine from working rotation to braking mode, as well as to the opposite rotation mode occurs due to the introduction of new connections and blocks into the circuit.

The essence of the utility model is illustrated by drawings.

Figure 1 presents a block diagram of a control device for a contactless DC motor.

Figure 2 shows a graph of permissible zones of operating states of the engine (m, i, ω).

On figa, 3b, 3c presents a diagram of the DC motor:

3a) forward direction (forward);

3b) reverse direction (backward);

3c) engine switching circuit.

Figure 1 introduced the following notation:

- power source 1;

- inverter 2;

- current sensor 3;

- synchronous electric motor 4;

- load 5;

- block 6 comparators;

- block 7 drivers;

- block 8 phase switch;

- control unit 9;

- current regulator 10;

- current comparison circuit 11;

- speed controller 12;

- speed comparison circuit 13;

- block 14 of the setpoint maximum speed;

- block 15 of the master pace of braking;

- block 16 of the accelerator;

- block 17 sets the maximum current.

The control device for a contactless DC motor contains a power source 1, one output of which is connected to the input of the inverter 2, and the other output is connected to a current sensor 3, while the first output of the inverter 2 is connected to a synchronous electric motor 4, on the shaft of which there is a load of 5, and the second output of the inverter 2 is connected to the input of the comparator unit 6, the second input of the inverter 2 is connected to the output of the driver unit 7, the input of which is connected to the output of the phase switching unit 8, the first input of which is connected to the output of the control unit 9 two other inputs of the phase switching unit 8 are connected to the first outputs of the braking ramp unit 15 and the acceleration ramp unit 16, the second outputs of which are connected to two inputs of the control unit 9, and the third input of the control unit 9 is connected to the output of the current regulator 10, the input of which is connected to the output of the current comparison circuit 11, the first input of which is connected to the output of the overcurrent master unit 17, the second input of which is connected to the output of the current sensor 3, and the third input of the current comparison circuit 11 is connected to the controller output and 12 speeds, the input of which is connected to the output of the speed comparison circuit 13, the first input of which is connected to the output of the comparator unit 6, and the second input of the speed comparison circuit 13 is connected to the output of the maximum speed setter unit 14.

The control device for a contactless DC motor is made on standard units. So, for example, power supply 1 is used of type Power Supply EA-9300-02, inverter 2 is of type GB25RF120K, block 7 of drivers is type IR2214SS, block 6 of comparators and current comparison circuit 11 and speed comparison circuit 13 are built on comparators of type LM2390, block 14 of the maximum speed setter, block 15 of the set rate of braking, block 16 of the set point of acceleration and block 17 of the set point of maximum current are selected depending on the parameters of the engine (power, control range, etc.). In this case, the control range is ω _max / ω _min = 10 at a power of about 500 W to 5000 W, a potentiometric type is selected according to the maximum supply voltage of the control circuits and driver circuits (Un = 5 ÷ 15 V). A PID type speed controller and a PD type current controller are standard, taking into account the output to the control unit, built on the PIC16F628A microprocessor. The motor is a non-contact synchronous magnetoelectric type and a stator winding made on each stator tooth. Such an engine has a large overload capacity, the best heat cooling conditions, while simplifying the technology of laying the windings in the stator slots and reducing the probability of insulation breakdown in the motor windings. The current sensor 3 can be performed in various ways. For example, the current sensor 3 is the usual small resistance installed in the negative bus supplying the inverter, and the maximum speed controller unit 14 can be formed, for example, by applying a tachogenerator winding to the stator teeth or any other type of tachogenerator (for example, a non-contact low-power machine synchronous or asynchronous type). The proposed control device of a contactless DC motor operates as follows:

From the power source 1 to the inverter 2 receives the supply voltage (rated) and the current corresponding to the rated torque. In this case, the speed will correspond to the nominal, with a certain direction of rotation (we will conditionally accept the direction - as forward, when applied to a typical drive). In this mode (taking into account the specific load), the braking rate controller unit 15 and the acceleration rate controller unit 16 are selected from the condition of the maximum possible acceleration of the drive (dα / dt), where α is the angle of rotation of the engine, t is the transient time, which is defined as electromechanical T _em , and the electromagnetic constant T _{a of the} drive, and also depends on the magnitude of the load on the shaft of a non-contact DC motor. At the same time, the control unit 9, which forms the switching logic of the power switches of the inverter 2, can speed up or slow down the acceleration and deceleration process by processing the signals of the acceleration ramp unit 16 and the braking ramp unit 15, both in speed and in speed current without exceeding their maximum set values determined by the maximum speed setter unit 14 and the maximum current setter unit 17. When a reverse mode occurs (rotation of a non-contact DC motor - back), the fastest way to change its direction of rotation of the stator magnetic field is the opposite. In this case, there are three possible modes (figure 2):

a) smooth braking to n≤n _n

b) sharp braking to n = 0.

c) reverse from change + n _n to -n _n

These modes are determined by both the magnitude and duration of the PWM signals during forward and reverse rotation of the contactless motor

direct current.

When you change the sign entering the phase switching unit from the control unit, the direction of the phase rotation changes (U, V, W) - forward rotation, (U, W, V) - reverse rotation (figa, 3b). At the same time, due to the accumulation of kinetic energy and a change in the sign of the opposite EMF of the motor, the current I _max can reach unacceptable values, which requires the use of block 17 of the setpoint maximum current ± I _max .

Figure 2 presents three types of current signals generated by the block 7 of the drivers in three modes:

a) direct inclusion n≤n _n , I = + I _n = I _cp (square 1 ω = f (i));

b) stop n = 0, I = 0;

c) the reverse inclusion n≤-n _n , I = -I _n = -I _cp (square 3 -ω = f (-i)).

For accelerated acceleration and braking at the shortest possible process time, it is necessary to provide the maximum possible (for this type of non-contact DC motor) torque and braking, which is achieved by the maximum possible current both during acceleration and braking. At the same time, if the engine has an operation sequence, where the acceleration and deceleration periods alternate, then to increase the operation cycles (and therefore reduce the cycle time), it is necessary to select an acceleration and deceleration cycle so that the transient acceleration and deceleration time is as low as possible, which is acceptable only at the maximum possible moment on the motor shaft both during acceleration and braking, i.e. in the presence of maximum dynamic moment on the shaft.

In Figure 3D is a diagram rapid acceleration and deceleration 2 · (t _p + t _t) = T _p (T _p - time control cycle).

The control circuit operates as a dual-circuit control system (speed loop and current loop), and the speed loop, as less fast (with constant electromechanical constant T _e / _mech ) includes a current control loop (with constant electromagnetic T _em ), usually T _{e / mech} >> T _em , that implements the principle of subordinate control of the drive torque. This includes starting and braking control in the torque control system. The application of the brake ramp unit and the acceleration ramp unit depends on the specific load and the maximum possible current, which maintains a constant dynamic moment.

The use of the claimed control device for a contactless DC motor allows you to reduce the time of accelerated acceleration and accelerated braking in the sequence diagram of the technological process.

Claims (1)

A control device for a contactless DC motor characterized in that it contains a power source, one output of which is connected to the input of the inverter, and the other output is connected to a current sensor, while the first output of the inverter is connected to a synchronous motor, on the shaft of which there is a load, and the second the inverter output is connected to the input of the comparator unit, the second inverter input is connected to the output of the driver unit, the input of which is connected to the output of the phase switching unit, the first input of which is connected to the output the control unit’s house, and the other two inputs of the phase switching unit are connected to the first outputs of the brake ramp unit and the acceleration ramp block, the second outputs of which are connected to two inputs of the control unit, and the third input of the control unit is connected to the output of the current regulator, the input of which is connected to the output of the current comparison circuit, the first input of which is connected to the output of the overcurrent unit, the second input of which is connected to the output of the current sensor, and the third input of the current comparison circuit is connected to the regulator output speed torus, whose input is connected to the output of the comparison circuit speed, the first input coupled to an output comparator block and a second input of the comparison circuit is connected to the output of the setpoint speed maximum speed.