[0039] The following description and the drawings fully illustrate the specific embodiments of the present invention so that those skilled in the art can practice them. The following examples and the accompanying drawings will further illustrate the technical solutions of the present invention in detail.
[0040] reference figure 1 , The circuit diagram of the rectifier filter circuit of the present invention is given;
[0041] The rectifier filter circuit is composed of a single-phase bridge rectifier circuit and an LC-π filter circuit;
[0042] The single-phase bridge rectifier circuit includes: a power transformer, a rectifier diode VD1, a rectifier diode VD2, a rectifier diode VD3, a rectifier diode VD4, and a load resistor RL; wherein the rectifier diode VD1, rectifier diode VD2, rectifier diode VD3, The rectifier diode VD4 forms a rectifier bridge;
[0043] The transformer converts the AC voltage of the power grid into the AC voltage required by the single-phase bridge rectifier circuit. During the positive half cycle of the sinusoidal AC power supply, the rectifier diode VD1 is forward-conducted, and the rectifier diode VD2 is reversely blocked, and the current flows through The rectifier diode VD1 and the load resistance RL return to the zero point of the center tap of the transformer to form a loop;
[0044] The load resistance RL obtains the half-wave rectified voltage and current. When the power supply voltage is in the positive half cycle of U2, the potential of terminal a of the transformer secondary winding is higher than the potential of terminal b, VD1 and VD3 are turned on under the action of the forward voltage, and VD2 And VD4 is cut off under the action of reverse voltage, the current starts from end a of the secondary winding of the transformer, passes through VD1, RL, VD3, and returns to end b to form a path, and the current flows through the load resistance RL.
[0045] LC-π filter circuit is composed of inductor, capacitor filter and LC filter;
[0046] After the AC current is rectified, most of the AC component is stopped by the inductor group, and a small part passes through the inductor, and then is double-filtered by the capacitor filter and the LC filter to obtain a smoother voltage.
[0047] reference figure 2 , The block diagram of the first-level voltage compensation circuit of the present invention is given;
[0048] The first-level voltage compensation circuit includes: voltage regulator resistor R, voltage regulator transistor VT, load RL, voltage divider resistor R1, voltage divider resistor R2, compensation resistor R3, compensation resistor R4, contactor, relay, anti-backflow diode VD1 and stabilizer Voltage diode VDZ;
[0049] The voltage stabilizing resistor R, the voltage stabilizing transistor VT, and the load RL are connected in series. When the output voltage UO changes due to the change of the load RL, the change of the voltage UO will be reflected on the transmitting junction voltage of the voltage stabilizing transistor VT, so The voltage stabilizing transistor VT realizes a series stabilizing circuit through a series stabilizing resistor, thereby adjusting the voltage UO to keep the output voltage basically stable;
[0050] The compensation resistors R3 and R4 are used to ensure that the compensation point is not suspended and accidentally disconnected during the switching process of the compensation point, which may cause excessive output of the power source and damage the load;
[0051] The Zener diode VDZ is packaged in glass, the reverse current suddenly increases, and the Zener diode VDZ enters the breakdown zone. At this time, even if the reverse current changes in a large range, the reverse voltage across the Zener diode Can also remain stable;
[0052] The voltage divider resistors R1 and R2, and the selected kiloohm resistors realize power supply output voltage sampling;
[0053] The conducting end of the anti-backflow diode VD1 is electrically connected to a contactor, and the contactor realizes the control of the load power supply and prevents the current from returning;
[0054] The power supply receives the power supply instruction to close the contactor and the relay, and the load terminal voltage is divided by the voltage divider resistors R1 and R2 and then sent to the power input terminal. After being adjusted by an external regulator, the power supply output is regulated; the power supply is realized The working sequence of the circuit when the compensation circuit is turned on first, and then the load is turned on, avoids the risk of damage to the load device when the compensation circuit is turned on first.
[0055] reference image 3 , The structure block diagram of the multi-channel detection isolation unit in the secondary isolation compensation module of the present invention is given;
[0056] Secondary isolation compensation module, including:
[0057] Multi-channel detection isolation unit, including multi-channel switch, shift register, communication isolation module 1 and communication isolation module 2;
[0058] The multi-channel detection isolation unit is used to detect multi-channel voltage signals. It is equipped with 3 single-ended 8-channel multiplexers, each single-ended single-channel multiplexer detects one channel at the same time, and passes through the shift register. Serial to parallel port control; at the same time, the communication isolation module 1 can read 3 voltage signals, and through the communication isolation module 2 for 8 times of control to read, it can read all the above 24 signals, achieving the least number of pins Read the most voltage.
[0059] reference Figure 4 , Given the structure block diagram of the voltage comparison module of the present invention;
[0060] Voltage comparison module, including comparator, DC-DC step-down module, isolator;
[0061] The voltage signal provides an external power supply, providing a set of isolated square wave signals. The external power supply first provides power to the isolated comparator, and then provides voltage to the isolation device through the DC-DC step-down module. The generated voltage is then divided into a voltage The reference voltage is used by the comparator. The voltage signal output by the isolator is compared with the reference voltage to generate a square wave signal with the same amplitude as the external voltage through the comparator. The final square wave signal is the real voltage transmitted to the load. The fluctuation of the wave signal can compare and analyze the voltage of the load.
[0062] reference Figure 8 , The structural block diagram of the high-voltage signal isolation unit of the present invention is given;
[0063] High voltage signal isolation unit, including displacement buffer and high voltage solid state relay;
[0064] The displacement buffer is serially inputted and outputted in parallel through a serial port to a parallel port;
[0065] Each of the displacement buffers can realize 8-channel output control. After n displacement buffers are cascaded, the 8-channel signal control can be realized through 3 control lines;
[0066] The high-voltage solid-state relay is used to isolate the output from the control, and the high-voltage solid-state relay sends a high-voltage signal to one end of the output side, and when the output is required, the high-voltage solid-state relay is switched to the output side for output use.
[0067] reference Figure 5 , Given the block diagram of the analog-to-digital conversion isolation unit of the present invention;
[0068] Analog-to-digital conversion isolation unit, including: DAC (analog-to-digital converter), isolated power supply, reference voltage module, operational amplifier;
[0069] The current-type DAC selected by the DAC will generate a low power supply voltage for the isolation communication components after external power supply, eliminating the need for an additional step-down module;
[0070] The DAC communicates with isolated communication components to generate a voltage of a certain amplitude, the reference voltage module has a certain range of reference voltage, the isolated power supply supplies power to the DAC and its reference voltage module through step-down, and the reference voltage module provides a voltage to the DAC The reference ensures the accuracy of the voltage generated by the DAC. The reference voltage and the voltage generated by the DAC generate the required DC voltage signal through the operational amplifier.
[0071] reference Image 6 , A block diagram of the current isolation module structure of the present invention is given;
[0072] Current isolation module, including: high-speed DAC, high-speed isolated operational amplifier, isolated power supply;
[0073] The high-speed DAC uses 12 data lines for communication, which can realize arbitrary waves;
[0074] The high-speed isolated operational amplifier is used to achieve isolation. In order to meet the requirements of amplitude and current drive capability, a current-type operational amplifier is used for operational amplification to finally achieve the required analog waveform output; in terms of power supply, an isolated power supply is used , The step-down power supply supplies power to the isolated op amp, and the unstepped power supply directly supplies power to the current-type op amp.
[0075] reference Figure 7 , The circuit diagram of the current acquisition circuit of the present invention is given;
[0076] Current acquisition circuit, including: current sensor, sampling resistor, bias resistor, controller and diode;
[0077] After the current sensor converts the power supply current into a small signal current, it is converted into a voltage signal by a sampling resistor, followed and biased, and then sent to the controller for processing. The bias resistor biases the voltage signal to improve Acquisition accuracy of small current;
[0078] The diode is a double Schottky diode, which has a low conduction voltage drop and is suitable for a voltage clamp protection controller;
[0079] The stabilized power supply works in the on-off state, and high-frequency interference is easily introduced into the analog signal. Therefore, the current acquisition circuit uses the Hall current sensor isolation method to collect current, which realizes real-time monitoring of the power consumption of the electric load and realizes the stabilized power supply. Protection control, and collect the output current of the regulated power supply;
[0080] The secondary isolation compensation module realizes the isolation of the voltage regulation signal from the regulated power supply, improves the anti-interference of the entire power system, realizes the isolation of analog signals, and improves the anti-interference of the entire power system.
[0081] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still possible for those skilled in the art to modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some of the technical features. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.
