A power supply powered add-on control system

Abstract

This invention relates to a power supply auxiliary control system. The system adds the following components to the DC bus side of the power supply load-side converter: a load unloading circuit for dissipating excess energy; a signal acquisition circuit for detecting power and current on both sides of the load-side converter; and a load unloading circuit control circuit including: a logic control and protection module that generates an auxiliary control signal based on the acquired DC bus current and load-side current values; and a control pulse generation module that generates a trigger signal based on the power deviation between the acquired DC bus power and load-side power, and, combined with the auxiliary control signal output from the logic control and protection module, outputs a load unloading circuit control signal to control the switching of the load unloading circuit. Compared with existing technologies, this invention dissipates excess power by generating a signal through the control circuit to control the switching of the load unloading circuit, protecting the load-side converter from high-current surges, preventing power supply failures and extending the lifespan of its electronic components.

Description

Technical Field

[0001] This invention relates to the field of power supply control technology, and in particular to a power supply control system. Background Technology

[0002] When a power supply for a large load is in operation, if there is a sudden load change such as load disconnection or cessation of operation, the current on the load side will drop sharply. Since the current on the DC bus side takes time to slowly decrease, a large power difference will be generated on both sides of the load-side converter, that is, between the load and the DC bus, which can easily damage the electronic components inside the load-side converter.

[0003] Traditional power supply overcurrent and overpower protection generally only consider the risk of adapter overload caused by excessive current consumed by the load, but does not consider the impact of the instantaneous drop in current on the load side after a large load is cut off, which leads to power overshoot on the DC bus side and affects the converter. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a power supply control system.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A power supply auxiliary control system, wherein the system is added to the DC bus side of the power load-side converter:

[0007] Unloading circuits are used to dissipate excess energy;

[0008] The signal acquisition circuit is used to detect the power and current on both sides of the load-side converter;

[0009] The unloading circuit control circuit includes:

[0010] The logic control and protection module generates additional control signals based on the DC bus current and load-side current values ​​acquired by the signal acquisition circuit.

[0011] The control pulse generation module generates a trigger signal based on the power deviation between the DC bus power and the load-side power acquired by the signal acquisition circuit. Combined with the additional control signal output by the logic control and protection module, it outputs a control signal for the unloading circuit to control the switching of the unloading circuit.

[0012] As a preferred technical solution, the unloading unit includes at least a thyristor, and the positive terminal of the thyristor is connected to the positive terminal of the DC bus.

[0013] As a preferred technical solution, the signal acquisition circuit includes current transformers and voltage transformers disposed on the load side and the DC bus side.

[0014] As a preferred technical solution, the logic control and protection module includes: a subtractor, a hysteresis comparator, a differentiating circuit, and a falling edge triggered delay.

[0015] As a preferred technical solution, the subtractor calculates the difference between the DC bus current acquired by the signal acquisition circuit and the load-side current value, and then inputs the difference into the hysteresis comparator; the hysteresis comparator compares the difference with the set upper and lower limits of the current difference.

[0016] As a preferred technical solution, the input of the differentiating circuit is the load-side current, and the output of the differentiating circuit is the rate of change of the differentiating circuit to the falling edge trigger delay unit. After the delay, the falling edge trigger delay unit inputs an enable signal to the enable terminal of the hysteresis comparator.

[0017] As a preferred technical solution, after the load-side current drops rapidly, the logic control and protection module outputs an enable signal from the falling edge trigger delay to enable the hysteresis comparator to start comparison; when the current difference is within the set reference difference, the additional control signal output is 0; when the current difference exceeds the set reference difference, the additional control signal output is 1.

[0018] As a preferred technical solution, the control pulse generation module includes a subtractor, a proportional-integral controller, a pulse generator, and a controlled switch connected in sequence.

[0019] As a preferred technical solution, the inputs of the subtractor are the DC bus power and the load-side power acquired by the signal acquisition circuit, respectively; the input of the proportional-integral controller is the power deviation output by the subtractor, and the output duty cycle is D; the pulse generator generates a trigger signal according to the duty cycle D and inputs it to one end of the controlled switch; the control terminal of the controlled switch is connected to the additional control signal output from the logic control and protection module, and outputs the unloading circuit control signal.

[0020] As a preferred technical solution, the additional control system further includes a drive output module, which is a drive amplification unit used to amplify the control signal of the unloading circuit.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention proposes a power supply auxiliary control circuit. By adding a load shedding circuit on the DC bus side of the load-side converter, when a sudden load change occurs, the detection circuit can detect the sudden drop in current on the load side, and the control circuit generates a signal to control the switching of the load shedding circuit, thereby dissipating excess power, protecting the load-side converter from the impact of large current, avoiding power supply failure and damage, and extending the service life of its electronic components. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the power supply auxiliary control system of the present invention;

[0024] Figure 2 This is a circuit structure diagram of the logic control and protection module of the present invention;

[0025] Figure 3 This is a circuit diagram of the control pulse generation module of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0027] Example 1

[0028] This invention provides a power supply auxiliary control system, such as... Figure 1 As shown, it includes an unloading unit for dissipating excess energy; a signal acquisition circuit for detecting power and current on both sides of the load-side converter; a logic control and protection module for generating additional control signals based on the DC bus current and load-side current values ​​acquired by the signal acquisition circuit; and a control pulse generation module for generating trigger signals based on the power deviation between the DC bus power and load-side power acquired by the signal acquisition circuit, and combining the unloading control signals output by the logic control and protection module to output unloading circuit control signals.

[0029] The unloading unit is used to handle the surplus power of the AC system in the event of a fault in the AC system. The unloading unit includes at least a thyristor, and the positive terminal of the thyristor is connected to the positive terminal of the DC bus.

[0030] The signal acquisition circuit includes current transformers (CTs) and voltage transformers (PTs) installed on the load side and the DC bus side, which are used to acquire the current and power on both sides of the converter on the load side.

[0031] like Figure 2As shown, the logic control and protection module includes a subtractor, a hysteresis comparator, a differentiating circuit, and a falling edge triggered delay. The subtractor calculates the difference between the DC bus current and the load-side current acquired by the signal acquisition circuit, and then inputs this difference to the hysteresis comparator. The hysteresis comparator compares this difference with set upper and lower limits. The load-side current, after passing through the differentiating circuit, has its rate of change obtained; its output is delayed by a falling edge triggered delay before being input to the enable terminal of the hysteresis comparator. When the load is disconnected, the load-side current drops rapidly, and an enable signal is output to start the hysteresis comparator comparison. After the current stops decreasing, the comparison stops after a short delay, ensuring the smoothness of DC bus power control. When the current difference is within the set reference difference, the additional signal Ctrl is "0"; when the current difference exceeds the set reference difference, the additional control signal Ctrl is output as "1" and input to the control pulse generation module to generate the unloading circuit control signal.

[0032] like Figure 3 As shown, the control pulse generation module includes a subtractor, a proportional-integral controller, a pulse generator, and a controlled switch. The power deviation between the load-side converter and the input signal acquisition circuit is input to the proportional-integral controller to calculate the duty cycle D. The pulse generator then generates a trigger signal based on the duty cycle D. The input to position 1 of the controlled switch is the generated trigger signal, and the input to position 2 is 0. The controlled switch receives an additional control signal Ctrl generated by the logic control and protection module. When the additional control signal Ctrl is "1", it outputs the trigger signal generated by the pulse generator; when the additional signal Ctrl is "0", the additional control output duty cycle is 0, thus obtaining the unloading circuit control signal.

[0033] The drive output module is a drive amplification unit that amplifies the trigger pulse output from the voltage regulation and pulse generation module to drive the insulated gate bipolar transistor (IGBT) device in the unloading circuit and control the connection and disconnection of the unloading resistor.

[0034] When the power supply is in normal operating condition, the additional control circuit is locked; when the load is disconnected, the additional control circuit is activated, based on the power deviation ΔP = P on both sides of the converter. A -P R The duty cycle D = k is calculated using proportional-integral operations. p (P A -P R )+k i ∫(P A -P R )dt, 0≤D≤1, k p k i These are the proportional coefficient and the integral coefficient, respectively. When the current I on both sides of the converter... R and IA When the difference is less than the set value, the additional control exits and the power supply returns to normal control.

[0035] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A power supply auxiliary control system, characterized in that, The system adds the following to the DC bus side of the power load-side converter: Unloading circuits are used to dissipate excess energy; The signal acquisition circuit is used to detect the power and current on both sides of the load-side converter; The unloading circuit control circuit includes: The logic control and protection module generates additional control signals based on the DC bus current and load-side current values ​​acquired by the signal acquisition circuit. The control pulse generation module generates a trigger signal based on the power deviation between the DC bus power and the load-side power acquired by the signal acquisition circuit. Combined with the additional control signal output by the logic control and protection module, it outputs a control signal for the unloading circuit to control the switching of the unloading circuit.

2. The power supply auxiliary control system according to claim 1, characterized in that, The unloading unit includes at least a thyristor, the positive terminal of which is connected to the positive terminal of the DC bus.

3. The power supply auxiliary control system according to claim 1, characterized in that, The signal acquisition circuit includes current transformers and voltage transformers installed on the load side and the DC bus side.

4. The power supply auxiliary control system according to claim 1, characterized in that, The logic control and protection module includes: a subtractor, a hysteresis comparator, a differentiating circuit, and a falling edge triggered delay.

5. A power supply auxiliary control system according to claim 4, characterized in that, The subtractor calculates the difference between the DC bus current acquired by the signal acquisition circuit and the load-side current value, and then inputs the result into the hysteresis comparator. The hysteresis comparator then compares the result with the set upper and lower limits of the current difference.

6. The power supply auxiliary control system according to claim 4, characterized in that, The input to the differentiating circuit is the load-side current. The output of the differentiating circuit is the rate of change of the differentiating circuit, which is sent to the falling edge trigger delay unit. After the delay, the falling edge trigger delay unit inputs an enable signal to the enable terminal of the hysteresis comparator.

7. A power supply auxiliary control system according to any one of claims 4-6, characterized in that, After the load-side current drops rapidly, the logic control and protection module outputs an enable signal from the falling edge trigger delay to enable the hysteresis comparator to start comparison. When the current difference is within the set reference difference, the additional control signal output is 0; when the current difference exceeds the set reference difference, the additional control signal output is 1.

8. The power supply auxiliary control system according to claim 1, characterized in that, The control pulse generation module includes a subtractor, a proportional-integral controller, a pulse generator, and a controlled switch connected in sequence.

9. A power supply auxiliary control system according to claim 8, characterized in that, The inputs to the subtractor are the DC bus power and the load-side power acquired by the signal acquisition circuit, respectively; the input to the proportional-integral controller is the power deviation output by the subtractor, and the output duty cycle is D; the pulse generator generates a trigger signal according to the duty cycle D and inputs it to one end of the controlled switch; the control terminal of the controlled switch is connected to the additional control signal output from the logic control and protection module, and outputs the unloading circuit control signal.

10. A power supply auxiliary control system according to claim 1, characterized in that, The additional control system also includes a drive output module, which is a drive amplification unit used to amplify the control signal of the unloading circuit.

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