A non-stop switching system and method for low-voltage area based on a mobile power generation vehicle

Abstract

The present invention discloses a non-stop switching system and method for low-voltage substations based on a mobile power generation vehicle, comprising a city power grid, a load, a low-voltage distribution box JP1, a power switching device, and a power generation vehicle G1 for providing backup power. The No. 1 power input terminal of the low-voltage distribution box JP1 is electrically connected to the city power grid, the No. 1 power input terminal of the power switching device is electrically connected to the city power grid, the No. 2 power input terminal of the power switching device is electrically connected to the power generation vehicle G1, the No. 2 power input terminal of the low-voltage distribution box JP1 is electrically connected to the power output terminal of the power switching device, and the power output terminal of the low-voltage distribution box JP1 is electrically connected to the load. The present invention has the advantages of realizing non-stop smooth transition of the load and high safety.

Description

Technical Field

[0001] The present invention relates to the technical field of power switching, and more specifically to a low-voltage power switching system and method based on a mobile power generation vehicle. Background Art

[0002] The "power outage" load reversal is mainly based on the consideration of the safety and stability of the upper system. Its main purpose is to transfer the reversed load from the grid side to the generator side for power supply, which is convenient for the operation and maintenance of the upper equipment. But its cost is that all loads on the reversed line will be shut down for a short time, which not only loses load power but also causes a decrease in power supply reliability, affecting normal production order and even causing significant economic losses.

[0003] In addition, in the 0.4kV low-voltage system, the scheme of connecting to the grid first and then switching to achieve power reversal between the city power and the generator car has been applied. However, in actual applications, since the generator car and the grid are connected to the grid in a quasi-synchronous manner, the uncertainty of the closing time of the grid-connected circuit breaker will inevitably lead to a deviation in the grid-connected phase, which will cause a large impact current to the grid-connected unit, causing a strong impact on the unit and the system. At the same time, after the grid is connected, the power of the generator car may be reversed to the high-voltage grid side. In severe cases, the high-voltage side circuit breaker will trip and protect, which poses certain safety hazards. In order to solve the safety constraints in the existing asynchronous grid connection from the perspective of technological innovation, and further improve the reliability and safety of non-stop operation switching in the 0.4kV low-voltage area, a new non-stop switching scheme is urgently needed to achieve a non-stop smooth transition of the load. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned technical deficiencies and provide a low-voltage substation non-stop power switching system and method based on a mobile power generation vehicle, applying the power supply phase difference change prediction technology and the excitation synchronous drive technology to the conversion system, thereby realizing a smooth transition and switching of the load between the power grid and the power generation vehicle, so that it has significant advantages such as fast conversion speed, high synchronization performance, low static loss, and good comprehensive performance.

[0005] The present invention discloses a non-stop power switching system and method for a low-voltage substation based on a mobile power generation vehicle, comprising a municipal power grid, a load, a low-voltage distribution box JP1, a power switching device and a power generation vehicle G1 for providing backup electric energy, wherein a No. 1 power input terminal of the low-voltage distribution box JP1 is electrically connected to the municipal power grid, a No. 1 power input terminal of the power switching device is electrically connected to the municipal power grid, a No. 2 power input terminal of the power switching device is electrically connected to the power generation vehicle G1, a No. 2 power input terminal of the low-voltage distribution box JP1 is electrically connected to a power output terminal of the power switching device, and a power output terminal of the low-voltage distribution box JP1 is electrically connected to the load.

[0006] Preferably, an air switch is provided in the No. 1 power input terminal of the low-voltage distribution box JP1, one end of the air switch is electrically connected to the city grid, and the other end of the air switch is electrically connected to the load.

[0007] Preferably, the power switching device includes a main control unit MC1, a circuit breaker J1, a circuit breaker J2, a circuit breaker J3, an excitation type transfer switch TSE1, an excitation type transfer switch TSE2, an excitation energy storage unit, a current sensor CT1, a current sensor CT2, a voltage sensor PT1, a voltage sensor PT2 and a voltage sensor PT3, wherein the voltage sensor PT1, the voltage sensor PT2 and the voltage sensor PT3 are respectively installed on the main control unit MC1, the excitation coil control end of the excitation type transfer switch TSE1 and the excitation coil control end of the excitation type transfer switch TSE2 are respectively electrically connected to the main control unit MC1, the left end of the excitation type transfer switch TSE1 is electrically connected to the right end of the circuit breaker J1, and the right end of the excitation type transfer switch TSE1 is electrically connected to the left end of the current sensor CT1, The left end of the circuit breaker J1 is electrically connected to the No. 1 power input terminal of the low-voltage distribution box JP1, the left end of the excitation type transfer switch TSE2 is electrically connected to the right end of the circuit breaker J2, the left end of the circuit breaker J2 is electrically connected to the power generation vehicle, the right end of the excitation type transfer switch TSE2 is electrically connected to the left end of the current sensor CT2, the right end of the current sensor CT1 and the right end of the current sensor CT2 are electrically connected to the voltage sensor PT3 respectively, and the node thereof is electrically connected to the other end of the air switch, and the current sensor CT The signal transmission end of the voltage sensor PT1 and the signal transmission end of the current sensor CT2 are electrically connected to the main control unit MC1 respectively, the detection end of the voltage sensor PT1 is electrically connected to the right end of the excitation type transfer switch TSE1, the detection end of the voltage sensor PT2 is electrically connected to the right end of the excitation type transfer switch TSE2, the right end of the excitation energy storage unit is electrically connected to the main control unit MC1, the left end of the excitation energy storage unit is electrically connected to the right end of the circuit breaker J3, and the left end of the circuit breaker J3 is electrically connected to the left end of the excitation type transfer switch TSE2.

[0008] Preferably, the excitation energy storage unit includes a voltage output unit, an energy storage C1 unit and an energy storage C2 unit, the voltage output unit includes a field effect transistor Q1, a field effect transistor Q2, a diode D3, a diode D4, a diode D5, a diode D6, a diode D7, a diode D8, a diode D9, a diode D10, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C21, a capacitor C35, a polar capacitor C22, a polar capacitor C23, a polar capacitor C24, a polar capacitor C25, a polar capacitor C26, and a polar capacitor C27, the positive electrode of the diode D3 is electrically connected to the negative electrode of the diode D5, and the The anode of the diode D4 is electrically connected to the cathode of the diode D6, the anode of the diode D5 is electrically connected to the anode of the diode D6, the cathode of the diode D9 is electrically connected to the anode of the diode D7, the cathode of the diode D10 is electrically connected to the anode of the diode D8, the cathode of the diode D7 is electrically connected to the cathode of the diode D8, the node where the anode of the diode D5 is connected to the anode of the diode D6 is electrically connected to the node where the cathode of the diode D10 is connected to the anode of the diode D8, the cathode of the diode D3 and the cathode of the diode D4 are electrically connected to one end of the resistor R7, respectively, the anode of the diode D9 and the anode of the diode D10 are electrically connected to one end of the resistor R13, respectively. The other end of the resistor R7 is electrically connected to one end of the resistor R8, the other end of the resistor R8 is electrically connected to the D pin of the field effect tube Q1, the S pin of the field effect tube Q1 is electrically connected to one end of the capacitor C21, the positive electrode of the polarity capacitor C22, the positive electrode of the polarity capacitor C23, the positive electrode of the polarity capacitor C24 and one end of the resistor R9 and grounded, the G pin of the field effect tube Q1 is electrically connected to the other end of the capacitor C21, the G pin of the field effect tube Q1 is electrically connected to the energy storage C1 unit, the other end of the resistor R13 is electrically connected to one end of the resistor R14, and the other end of the resistor R14 is electrically connected to one end of the capacitor C35 and the S pin of the field effect tube Q2 respectively. and grounded, the G pin of the field effect tube Q2 is electrically connected to the other end of the capacitor C35, the G pin of the field effect tube Q2 is electrically connected to the energy storage C2 unit, the D pin of the field effect tube Q2 is electrically connected to the negative electrode of the polar capacitor C25, the negative electrode of the polar capacitor C26, the negative electrode of the polar capacitor C27 and one end of the resistor R12 and grounded, the other end of the resistor R12 is electrically connected to one end of the resistor R11, and the other end of the resistor R11 is electrically connected to one end of the resistor R10, the negative electrode of the polar capacitor C22, the negative electrode of the polar capacitor C23, the negative electrode of the polar capacitor C24, the positive electrode of the polar capacitor C25, the positive electrode of the polar capacitor C26 and the positive electrode of the polar capacitor C27 and grounded,The other end of the resistor R10 is electrically connected to the other end of the resistor R9, one end of the resistor R9 is the positive output end of the voltage output unit, one end of the resistor R12 is the negative output end of the voltage output unit, the positive end of the diode D5 is the positive input end of the voltage output unit, the connection node between the resistor R10 and the resistor R11 is the negative input end of the voltage output unit, and the positive input end and the negative input end of the voltage output unit are electrically connected to the main control unit MC1 respectively.

[0009] Preferably, the energy storage C1 unit includes resistor R15, resistor R16, resistor R17, resistor R18, resistor R19, resistor R20, resistor R21, resistor R22, resistor R23, resistor R24, resistor R25, resistor R26, resistor R27, resistor R28, capacitor C36, capacitor C37, operational amplifier chip U5, optocoupler chip U6 and voltage regulator chip U7, one end of the resistor R19 is electrically connected to one end of the resistor R20, the other end of the resistor R20 is electrically connected to one end of the resistor R21, and the The other end of the resistor R21 is electrically connected to one end of the resistor R22, one end of the resistor R23 is electrically connected to one end of the resistor R24, the other end of the resistor R24 ​​is electrically connected to one end of the resistor R25, the other end of the resistor R25 is electrically connected to one end of the resistor R26, the other end of the resistor R19 is electrically connected to the other end of the resistor R23 and is grounded, the other end of the resistor R22 is electrically connected to one end of the resistor R15 and the 2nd pin of the operational amplifier chip U5, respectively, and the other end of the resistor R26 is electrically connected to the capacitor C37 respectively. One end of the voltage regulator chip U7, pin 1 of the voltage regulator chip U7, one end of the resistor R27, one end of the resistor R28 and pin 3 of the operational amplifier chip U5 are electrically connected, the other end of the resistor R15 is electrically connected to one end of the resistor R17, the other end of the resistor R17 is electrically connected to one end of the capacitor C36 and grounded, the other end of the capacitor C36 is electrically connected to one end of the resistor R16 and pin 5 of the operational amplifier chip U5 and connected to a +12V voltage, the other end of the resistor R16 is electrically connected to pin 1 of the optocoupler chip U6 The other end of the capacitor C37 is electrically connected to the pin 2 of the voltage regulator chip U7 and grounded, the pin 4 of the operational amplifier chip U5 is grounded, the other end of the resistor R28 is connected to the +12V voltage, the other end of the resistor R27 is electrically connected to the pin 1 of the operational amplifier chip U5 and the pin 2 of the optocoupler chip U6, the pin 3 of the optocoupler chip U6 is grounded, the pin 4 of the optocoupler chip U6 is electrically connected to one end of the resistor R18 and the G pin of the field effect tube Q1, and the other end of the resistor R18 is connected to the +12V voltage.

[0010] Preferably, the energy storage C2 unit includes resistor R38, resistor R40, resistor R41, resistor R42, resistor R43, resistor R44, resistor R45, resistor R46, resistor R47, resistor R48, resistor R49, resistor R50, resistor R51, resistor R52, capacitor C39, capacitor C40, operational amplifier chip U9, optocoupler chip U10 and voltage regulator chip U11, one end of the resistor R42 is electrically connected to one end of the resistor R43, the other end of the resistor R43 is electrically connected to one end of the resistor R44, and the The other end of the resistor R44 is electrically connected to one end of the resistor R45, one end of the resistor R47 is electrically connected to one end of the resistor R48, the other end of the resistor R48 is electrically connected to one end of the resistor R49, the other end of the resistor R49 is electrically connected to one end of the resistor R50, the other end of the resistor R42 is electrically connected to the other end of the resistor R47 and is grounded, the other end of the resistor R45 is electrically connected to one end of the resistor R41 and the 2nd pin of the operational amplifier chip U9, and the other end of the resistor R50 is electrically connected to one end of the capacitor C40. , pin 3 of the voltage regulator chip U11, pin 1 of the voltage regulator chip U11, one end of the resistor R51, one end of the resistor R52 and pin 3 of the operational amplifier chip U9 are electrically connected, the other end of the resistor R41 is electrically connected to one end of the resistor R38, the other end of the resistor R38 is electrically connected to one end of the capacitor C39 and grounded, the other end of the capacitor C39 is electrically connected to one end of the resistor R40 and pin 5 of the operational amplifier chip U9 and connected to a +12V voltage, the other end of the resistor R40 is electrically connected to pin 1 of the optocoupler chip U10 The other end of the capacitor C40 is electrically connected to pin 2 of the voltage regulator chip U11 and grounded, pin 4 of the operational amplifier chip U9 is grounded, the other end of the resistor R52 is connected to a +12V voltage, the other end of the resistor R51 is electrically connected to pin 1 of the operational amplifier chip U9 and pin 2 of the optocoupler chip U10, pin 3 of the optocoupler chip U10 is grounded, pin 4 of the optocoupler chip U10 is electrically connected to one end of the resistor R46 and pin G of the field effect transistor Q2, and the other end of the resistor R46 is connected to a +12V voltage.

[0011] The control method of the present invention:

[0012] 1) When the load needs to be transferred from the mains side to the generator car for power supply, the main control unit MC1 controls the voltage sensor PT1 and the voltage sensor PT3 to monitor the mains voltage signal and the generator car voltage signal respectively. The main control unit MC1 determines whether the voltage phase sequence and phase of the incoming line side and the load side of the excitation transfer switch TSE1 are consistent by analyzing the mains voltage signal and the generator car voltage signal. If consistent, the main control unit MC1 will close the excitation transfer switch TSE1. At this time, the low-voltage circuit breaker in the low-voltage distribution box JP1 is manually disconnected, so that the load power supply circuit passes through the circuit breaker J1 and the circuit where the excitation transfer switch TSE1 is located.

[0013] 2) At this time, the voltage sensor PT1 and the voltage sensor PT2 respectively monitor the voltage of the city power grid and the power generation vehicle in real time. Through the synchronization detection and phase difference change prediction of the main control unit MC1, combined with the action time characteristics of the excitation transfer switch TSE1 itself, the main control unit MC1 can predict the optimal time of the excitation coil drive command of the excitation transfer switch TSE2, so as to ensure that the phase difference between the contact closing time of the excitation transfer switch TSE2 and the city power grid is close to zero, that is, the excitation transfer switch TSE1 and the excitation transfer switch TSE2 are short-term connected in parallel to supply power to the load.

[0014] 3) At this time, the main control unit MC1 will make a judgment based on the instantaneous current collected by the current sensor CT2, and calculate the moment when the contacts of the excitation transfer switch TSE2 are closed; when the main control unit MC1 detects that the excitation transfer switch TSE2 is closed, the main control unit MC1 will immediately drive the excitation coil of the excitation transfer switch TSE1 to disconnect the contacts of the excitation transfer switch TSE1, and complete the power supply conversion from the mains to the generator car side without power outage.

[0015] 4) After the excitation energy storage unit takes power from the generator car side, it is used as the driving power supply for the excitation coils of the excitation conversion switch TSE1 and the excitation conversion switch TSE2 through rectification, boosting and constant voltage control. Through the constant voltage control of the energy storage unit and the constant pulse width drive control of the main control unit, the consistency of the excitation energy of the discharge drive at the driving moment is guaranteed, thereby ensuring the consistency and stability of the excitation conversion action characteristics and meeting the synchronous switching of the excitation conversion switch TSE1 and the excitation conversion switch TSE2.

[0016] The main control unit MC1 is a minimum system with a 32-bit single-chip microcomputer as its main body, and the model of the single-chip microcomputer is HC32L130J8TA.

[0017] The present invention realizes short-time parallel connection and switching between the power generation vehicle and the city power through the controllable excitation action time of the excitation type transfer switch, realizes smooth transition of the load without power outage, and utilizes the physical properties of the mechanical contacts to realize conduction stability and strong load-carrying capacity.

[0018] After drawing power from the generator car, the excitation energy storage unit charges, boosts and controls the constant voltage of the energy storage capacitor in the excitation energy storage unit to ensure that the energy stored in the energy storage capacitor remains constant, thereby ensuring the consistency and reliability of the excitation action characteristics, thereby realizing the synchronous switching and control of the excitation conversion switch.

[0019] The present invention has the function of quasi-synchronous detection of the two power supplies on the mains and the generator car side. It detects and judges the frequency difference, voltage difference, phase sequence, phase difference and other parameters of the two power supplies through various sensors and the main control unit MC1, and predicts the time required for the phase difference to be zero through the phase difference change, thereby providing necessary characteristic parameters for excitation synchronous switching.

[0020] The present invention has the function of synchronous switching of excitation. In order to ensure that the switching device can realize synchronous switching on the city power grid and the power generation vehicle side, the contacts of the two-way excitation conversion switches need to basically achieve synchronous opening and closing (that is, when one side contact is connected, the other side contact just enters the disconnection moment), and the opening and closing time points of the two groups of contacts should be synchronized as much as possible or the opening and closing deviation should be within a certain range. Through the quasi-synchronous detection of the main control unit and the pre-judgment of the phase difference change amount, the appropriate time before the arrival of the zero phase angle difference is selected, and the excitation energy storage unit is controlled by the main control unit to drive the conversion switch excitation coil to quickly close the power supply circuit of the power generation vehicle, so as to realize the short-term grid connection of the city power grid and the power generation vehicle to supply energy to the load, and at the same time, the excitation switch on the city power side is driven to disconnect the power supply on the city power grid side at the moment when the excitation switch of the power generation vehicle is closed. Thereby, a smooth transition of the load from the separation of the power grid to the cutting-in of the power generation vehicle is realized.

[0021] The voltage signal acquisition of the present invention provides quasi-synchronous detection, phase sequence detection and phase difference prediction for the main control unit MC1. In addition to providing effective value calculation for overload and short circuit protection, the current signal acquisition of the present invention also provides three-phase instantaneous current modulus value calculation as an instantaneous detection means for the opening and closing of the excitation switch contacts, further improving the opening and closing synchronization performance of the excitation switch.

[0022] The present invention has the following beneficial effects: achieving smooth transition of loads without power outage and high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 It is a circuit principle block diagram of the present invention.

[0024] Attached Figure 2 It is a circuit principle diagram of the voltage output unit of the present invention.

[0025] Attached Figure 3 It is a circuit schematic diagram of the energy storage C1 unit of the present invention.

[0026] Attached Figure 4 It is a circuit schematic diagram of the energy storage C2 unit of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0028] Embodiment: According to the attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4 The present invention is further described. In this example, a low-voltage substation non-stop power switching system based on a mobile power generation vehicle comprises a municipal power grid, a load, a low-voltage distribution box JP1, a power switching device and a power generation vehicle for providing backup power. The No. 1 power input terminal of the low-voltage distribution box JP1 is electrically connected to the municipal power grid, the No. 1 power input terminal of the power switching device is electrically connected to the municipal power grid, the No. 2 power input terminal of the power switching device is electrically connected to the power generation vehicle, the No. 2 power input terminal of the low-voltage distribution box JP1 is electrically connected to the power output terminal of the power switching device, and the power output terminal of the low-voltage distribution box JP1 is electrically connected to the load.

[0029] An air switch is arranged in the No. 1 power input terminal of the low-voltage distribution box JP1, one end of the air switch is electrically connected to the city grid, and the other end of the air switch is electrically connected to the load.

[0030] The power switching device includes a main control unit MC1, a circuit breaker J1, a circuit breaker J2, a circuit breaker J3, an excitation type transfer switch TSE1, an excitation type transfer switch TSE2, an excitation energy storage unit, a current sensor CT1, a current sensor CT2, a voltage sensor PT1, a voltage sensor PT2 and a voltage sensor PT3. The voltage sensor PT1, the voltage sensor PT2 and the voltage sensor PT3 are respectively installed on the main control unit MC1. The excitation coil control end of the excitation type transfer switch TSE1 and the excitation coil control end of the excitation type transfer switch TSE2 are respectively electrically connected to the main control unit MC1. The left end of the excitation type transfer switch TSE1 is electrically connected to the right end of the circuit breaker J1. The right end of the excitation type transfer switch TSE1 is electrically connected to the left end of the current sensor CT1. The left end of the circuit breaker J1 is electrically connected to the No. 1 power input terminal of the low-voltage distribution box JP1, the left end of the excitation type transfer switch TSE2 is electrically connected to the right end of the circuit breaker J2, the left end of the circuit breaker J2 is electrically connected to the power generation vehicle, the right end of the excitation type transfer switch TSE2 is electrically connected to the left end of the current sensor CT2, the right end of the current sensor CT1 and the right end of the current sensor CT2 are electrically connected to the voltage sensor PT3 respectively, and the node thereof is electrically connected to the other end of the air switch, and the current sensor CT The signal transmission end of the voltage sensor PT1 and the signal transmission end of the current sensor CT2 are electrically connected to the main control unit MC1 respectively, the detection end of the voltage sensor PT1 is electrically connected to the right end of the excitation type transfer switch TSE1, the detection end of the voltage sensor PT2 is electrically connected to the right end of the excitation type transfer switch TSE2, the right end of the excitation energy storage unit is electrically connected to the main control unit MC1, the left end of the excitation energy storage unit is electrically connected to the right end of the circuit breaker J3, and the left end of the circuit breaker J3 is electrically connected to the left end of the excitation type transfer switch TSE2.

[0031] The excitation energy storage unit includes a voltage output unit, an energy storage C1 unit and an energy storage C2 unit. The voltage output unit includes a field effect tube Q1, a field effect tube Q2, a diode D3, a diode D4, a diode D5, a diode D6, a diode D7, a diode D8, a diode D9, a diode D10, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C21, a capacitor C35, a polar capacitor C22, a polar capacitor C23, a polar capacitor C24, a polar capacitor C25, a polar capacitor C26, and a polar capacitor C27. The positive electrode of the diode D3 is electrically connected to the negative electrode of the diode D5, and the positive electrode of the diode D4 is electrically connected to the diode D6. The cathode of the diode D6 is electrically connected, the anode of the diode D5 is electrically connected to the anode of the diode D6, the cathode of the diode D9 is electrically connected to the anode of the diode D7, the cathode of the diode D10 is electrically connected to the anode of the diode D8, the cathode of the diode D7 is electrically connected to the cathode of the diode D8, the node where the anode of the diode D5 is connected to the anode of the diode D6 is electrically connected to the node where the cathode of the diode D10 is connected to the anode of the diode D8, the cathode of the diode D3 and the cathode of the diode D4 are electrically connected to one end of the resistor R7 respectively, the anode of the diode D9 and the anode of the diode D10 are electrically connected to one end of the resistor R13 respectively, and the other end of the resistor R7 is electrically connected to One end of the resistor R8 is electrically connected, the other end of the resistor R8 is electrically connected to the D pin of the field effect tube Q1, the S pin of the field effect tube Q1 is electrically connected to one end of the capacitor C21, the positive electrode of the polar capacitor C22, the positive electrode of the polar capacitor C23, the positive electrode of the polar capacitor C24 and one end of the resistor R9 and grounded, the G pin of the field effect tube Q1 is electrically connected to the other end of the capacitor C21, the G pin of the field effect tube Q1 is electrically connected to the energy storage C1 unit, the other end of the resistor R13 is electrically connected to one end of the resistor R14, the other end of the resistor R14 is electrically connected to one end of the capacitor C35 and the S pin of the field effect tube Q2 and grounded, the G pin of the field effect tube Q2 is electrically connected to the capacitor C The other end of the resistor R11 is electrically connected to one end of the resistor R10, the negative electrode of the polarity capacitor C22, the negative electrode of the polarity capacitor C23, the negative electrode of the polarity capacitor C24, the positive electrode of the polarity capacitor C25, the positive electrode of the polarity capacitor C26 and the positive electrode of the polarity capacitor C27 and are grounded, the other end of the resistor R10 is electrically connected to the other end of the resistor R9,One end of the resistor R9 is the positive output end of the voltage output unit, one end of the resistor R12 is the negative output end of the voltage output unit, the positive electrode of the diode D5 is the positive input end of the voltage output unit, the connection node between the resistor R10 and the resistor R11 is the negative input end of the voltage output unit, and the positive input end of the voltage output unit and the negative input end of the voltage output unit are electrically connected to the main control unit MC1 respectively.

[0032] The energy storage C1 unit includes resistor R15, resistor R16, resistor R17, resistor R18, resistor R19, resistor R20, resistor R21, resistor R22, resistor R23, resistor R24, resistor R25, resistor R26, resistor R27, resistor R28, capacitor C36, capacitor C37, operational amplifier chip U5, optocoupler chip U6 and voltage regulator chip U7, one end of the resistor R19 is electrically connected to one end of the resistor R20, the other end of the resistor R20 is electrically connected to one end of the resistor R21, and the resistor R2 The other end of the resistor R1 is electrically connected to one end of the resistor R22, one end of the resistor R23 is electrically connected to one end of the resistor R24, the other end of the resistor R24 ​​is electrically connected to one end of the resistor R25, the other end of the resistor R25 is electrically connected to one end of the resistor R26, the other end of the resistor R19 is electrically connected to the other end of the resistor R23 and is grounded, the other end of the resistor R22 is electrically connected to one end of the resistor R15 and the 2nd pin of the operational amplifier chip U5, respectively, the other end of the resistor R26 is electrically connected to one end of the capacitor C37, respectively , pin 3 of the voltage regulator chip U7, pin 1 of the voltage regulator chip U7, one end of the resistor R27, one end of the resistor R28 and pin 3 of the operational amplifier chip U5 are electrically connected, the other end of the resistor R15 is electrically connected to one end of the resistor R17, the other end of the resistor R17 is electrically connected to one end of the capacitor C36 and grounded, the other end of the capacitor C36 is electrically connected to one end of the resistor R16 and pin 5 of the operational amplifier chip U5 and connected to a +12V voltage, the other end of the resistor R16 is electrically connected to pin 1 of the optocoupler chip U6 The other end of the capacitor C37 is electrically connected to pin 2 of the voltage regulator chip U7 and grounded, pin 4 of the operational amplifier chip U5 is grounded, the other end of the resistor R28 is connected to a +12V voltage, the other end of the resistor R27 is electrically connected to pin 1 of the operational amplifier chip U5 and pin 2 of the optocoupler chip U6, pin 3 of the optocoupler chip U6 is grounded, pin 4 of the optocoupler chip U6 is electrically connected to one end of the resistor R18 and pin G of the field effect transistor Q1, and the other end of the resistor R18 is connected to a +12V voltage.

[0033] The energy storage C2 unit includes resistor R38, resistor R40, resistor R41, resistor R42, resistor R43, resistor R44, resistor R45, resistor R46, resistor R47, resistor R48, resistor R49, resistor R50, resistor R51, resistor R52, capacitor C39, capacitor C40, operational amplifier chip U9, optocoupler chip U10 and voltage regulator chip U11, one end of the resistor R42 is electrically connected to one end of the resistor R43, the other end of the resistor R43 is electrically connected to one end of the resistor R44, and the resistor R4 The other end of the resistor R45 is electrically connected to one end of the resistor R45, one end of the resistor R47 is electrically connected to one end of the resistor R48, the other end of the resistor R48 is electrically connected to one end of the resistor R49, the other end of the resistor R49 is electrically connected to one end of the resistor R50, the other end of the resistor R42 is electrically connected to the other end of the resistor R47 and is grounded, the other end of the resistor R45 is electrically connected to one end of the resistor R41 and the 2nd pin of the operational amplifier chip U9, respectively, the other end of the resistor R50 is electrically connected to one end of the capacitor C40, the stabilizing Pin 3 of the voltage regulator chip U11, pin 1 of the voltage regulator chip U11, one end of the resistor R51, one end of the resistor R52 and pin 3 of the operational amplifier chip U9 are electrically connected, the other end of the resistor R41 is electrically connected to one end of the resistor R38, the other end of the resistor R38 is electrically connected to one end of the capacitor C39 and grounded, the other end of the capacitor C39 is electrically connected to one end of the resistor R40 and pin 5 of the operational amplifier chip U9 and connected to a +12V voltage, the other end of the resistor R40 is electrically connected to pin 1 of the optocoupler chip U10, The other end of the capacitor C40 is electrically connected to pin 2 of the voltage regulator chip U11 and grounded, pin 4 of the operational amplifier chip U9 is grounded, the other end of the resistor R52 is connected to a +12V voltage, the other end of the resistor R51 is electrically connected to pin 1 of the operational amplifier chip U9 and pin 2 of the optocoupler chip U10, pin 3 of the optocoupler chip U10 is grounded, pin 4 of the optocoupler chip U10 is electrically connected to one end of the resistor R46 and pin G of the field effect transistor Q2, and the other end of the resistor R46 is connected to a +12V voltage.

[0034] The control method of the present invention:

[0035] 1) When the load needs to be transferred from the mains side to the generator car for power supply, the main control unit MC1 controls the voltage sensor PT1 and the voltage sensor PT3 to monitor the mains voltage signal and the generator car voltage signal respectively. The main control unit MC1 determines whether the voltage phase sequence and phase of the incoming line side and the load side of the excitation transfer switch TSE1 are consistent by analyzing the mains voltage signal and the generator car voltage signal. If consistent, the main control unit MC1 will close the excitation transfer switch TSE1. At this time, the low-voltage circuit breaker in the low-voltage distribution box JP1 is manually disconnected, so that the load power supply circuit passes through the circuit breaker J1 and the circuit where the excitation transfer switch TSE1 is located.

[0036] 2) At this time, the voltage sensor PT1 and the voltage sensor PT2 respectively monitor the voltage of the city power grid and the power generation vehicle in real time. Through the synchronization detection and phase difference change prediction of the main control unit MC1, combined with the action time characteristics of the excitation transfer switch TSE1 itself, the main control unit MC1 can predict the optimal time of the excitation coil drive command of the excitation transfer switch TSE2, so as to ensure that the phase difference between the contact closing time of the excitation transfer switch TSE2 and the city power grid is close to zero, that is, the excitation transfer switch TSE1 and the excitation transfer switch TSE2 are short-term connected in parallel to supply power to the load.

[0037] 3) At this time, the main control unit MC1 will make a judgment based on the instantaneous current collected by the current sensor CT2, and calculate the moment when the contacts of the excitation transfer switch TSE2 are closed; when the main control unit MC1 detects that the excitation transfer switch TSE2 is closed, the main control unit MC1 will immediately drive the excitation coil of the excitation transfer switch TSE1 to disconnect the contacts of the excitation transfer switch TSE1, and complete the power supply conversion from the mains to the generator car side without power outage.

[0038] 4) After the excitation energy storage unit takes power from the generator car side, it is used as the driving power supply for the excitation coils of the excitation conversion switch TSE1 and the excitation conversion switch TSE2 through rectification, boosting and constant voltage control. Through the constant voltage control of the energy storage unit and the constant pulse width drive control of the main control unit, the consistency of the excitation energy of the discharge drive at the driving moment is guaranteed, thereby ensuring the consistency and stability of the excitation conversion action characteristics and meeting the synchronous switching of the excitation conversion switch TSE1 and the excitation conversion switch TSE2.

[0039] The above description is only a specific embodiment of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by persons in this field or outside this field without departing from the design principle of the present invention are all covered by the patent scope of the present invention.

Claims

1. A low-voltage area non-stop power switching system based on a mobile power generation vehicle, comprising a city power grid, a load, a low-voltage distribution box JP1, a power switching device and a power generation vehicle for providing backup power, characterized in that: The No. 1 power input terminal (1) of the low-voltage distribution box JP1 is electrically connected to the city grid, the No. 1 power input terminal (1) of the power switching device is electrically connected to the city grid, the No. 2 power input terminal (2) of the power switching device is electrically connected to the power generation vehicle, the No. 2 power input terminal (2) of the low-voltage distribution box JP1 is electrically connected to the power output terminal of the power switching device, and the power output terminal of the low-voltage distribution box JP1 is electrically connected to the load; an air switch is arranged inside the No. 1 power input terminal (1) of the low-voltage distribution box JP1, one end of the air switch is electrically connected to the city grid, and the other end of the air switch is electrically connected to the load; the power switching device comprises a main control unit MC1, a circuit breaker J1, and a circuit breaker J2, circuit breaker J3, excitation type transfer switch TSE1, excitation type transfer switch TSE2, excitation energy storage unit, current sensor CT1, current sensor CT2, voltage sensor PT1, voltage sensor PT2 and voltage sensor PT3, the voltage sensor PT1, voltage sensor PT2 and voltage sensor PT3 are respectively installed on the main control unit MC1, the excitation coil control end of the excitation type transfer switch TSE1 and the excitation coil control end of the excitation type transfer switch TSE2 are respectively electrically connected to the main control unit MC1, the left end of the excitation type transfer switch TSE1 is electrically connected to the right end of the circuit breaker J1, and the right end of the excitation type transfer switch TSE1 is electrically connected to the left end of the current sensor CT1, The left end of the circuit breaker J1 is electrically connected to the No. 1 power input terminal (1) of the low-voltage distribution box JP1, the left end of the excitation type transfer switch TSE2 is electrically connected to the right end of the circuit breaker J2, the left end of the circuit breaker J2 is electrically connected to the power generation vehicle, the right end of the excitation type transfer switch TSE2 is electrically connected to the left end of the current sensor CT2, the right end of the current sensor CT1 and the right end of the current sensor CT2 are electrically connected to the voltage sensor PT3 respectively, and the node thereof is electrically connected to the other end of the air switch, and the signal transmission end of the current sensor CT1 and the current sensor CT 2 signal transmission ends are electrically connected to the main control unit MC1 respectively, the detection end of the voltage sensor PT1 is electrically connected to the right end of the excitation type transfer switch TSE1, the detection end of the voltage sensor PT2 is electrically connected to the right end of the excitation type transfer switch TSE2, the right end of the excitation energy storage unit is electrically connected to the main control unit MC1, the left end of the excitation energy storage unit is electrically connected to the right end of the circuit breaker J3, and the left end of the circuit breaker J3 is electrically connected to the left end of the excitation type transfer switch TSE2; the excitation energy storage unit includes a voltage output unit, an energy storage C1 unit and an energy storage C2 unit,The voltage output unit includes a field effect transistor Q1, a field effect transistor Q2, a diode D3, a diode D4, a diode D5, a diode D6, a diode D7, a diode D8, a diode D9, a diode D10, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a capacitor C21, a capacitor C35, a polar capacitor C22, a polar capacitor C23, a polar capacitor C24, a polar capacitor C25, a polar capacitor C26, and a polar capacitor C27. The positive electrode of the diode D3 is electrically connected to the negative electrode of the diode D5, the positive electrode of the diode D4 is electrically connected to the negative electrode of the diode D6, and the positive electrode of the diode D5 is electrically connected to the negative electrode of the diode D7. The anode of the diode D6 is electrically connected, the cathode of the diode D9 is electrically connected to the anode of the diode D7, the cathode of the diode D10 is electrically connected to the anode of the diode D8, the cathode of the diode D7 is electrically connected to the cathode of the diode D8, the node where the anode of the diode D5 is connected to the anode of the diode D6 is electrically connected to the node where the cathode of the diode D10 is connected to the anode of the diode D8, the cathode of the diode D3 and the cathode of the diode D4 are electrically connected to one end of the resistor R7, the anode of the diode D9 and the anode of the diode D10 are electrically connected to one end of the resistor R13, the other end of the resistor R7 is electrically connected to one end of the resistor R8, and the cathode of the diode D5 is electrically connected to the anode of the diode D6. The other end of the resistor R8 is electrically connected to the D pin of the field effect tube Q1, the S pin of the field effect tube Q1 is electrically connected to one end of the capacitor C21, the positive electrode of the polar capacitor C22, the positive electrode of the polar capacitor C23, the positive electrode of the polar capacitor C24 and one end of the resistor R9 and grounded, the G pin of the field effect tube Q1 is electrically connected to the other end of the capacitor C21, the G pin of the field effect tube Q1 is electrically connected to the energy storage C1 unit, the other end of the resistor R13 is electrically connected to one end of the resistor R14, the other end of the resistor R14 is electrically connected to one end of the capacitor C35 and the S pin of the field effect tube Q2 and grounded, the G pin of the field effect tube Q2 is electrically connected to the other end of the capacitor C35 The G pin of the field effect tube Q2 is electrically connected to the energy storage C2 unit, the D pin of the field effect tube Q2 is electrically connected to the negative electrode of the polar capacitor C25, the negative electrode of the polar capacitor C26, the negative electrode of the polar capacitor C27 and one end of the resistor R12 and grounded, the other end of the resistor R12 is electrically connected to one end of the resistor R11, the other end of the resistor R11 is electrically connected to one end of the resistor R10, the negative electrode of the polar capacitor C22, the negative electrode of the polar capacitor C23, the negative electrode of the polar capacitor C24, the positive electrode of the polar capacitor C25, the positive electrode of the polar capacitor C26 and the positive electrode of the polar capacitor C27 and grounded, the other end of the resistor R10 is electrically connected to the other end of the resistor R9,One end of the resistor R9 is the positive output end of the voltage output unit, one end of the resistor R12 is the negative output end of the voltage output unit, the positive electrode of the diode D5 is the positive input end of the voltage output unit, the connection node between the resistor R10 and the resistor R11 is the negative input end of the voltage output unit, and the positive input end of the voltage output unit and the negative input end of the voltage output unit are electrically connected to the main control unit MC1 respectively; the energy storage C1 unit includes resistors R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, Resistor R25, resistor R26, resistor R27, resistor R28, capacitor C36, capacitor C37, operational amplifier chip U5, optocoupler chip U6 and voltage regulator chip U7, one end of the resistor R19 is electrically connected to one end of the resistor R20, the other end of the resistor R20 is electrically connected to one end of the resistor R21, the other end of the resistor R21 is electrically connected to one end of the resistor R22, one end of the resistor R23 is electrically connected to one end of the resistor R24, the other end of the resistor R24 ​​is electrically connected to one end of the resistor R25, the other end of the resistor R25 is electrically connected to one end of the resistor R26, the resistor R1 9 and the other end of the resistor R23 are electrically connected to the ground, the other end of the resistor R22 is electrically connected to one end of the resistor R15 and the 2nd pin of the operational amplifier chip U5, the other end of the resistor R26 is electrically connected to one end of the capacitor C37, the 3rd pin of the voltage stabilizing chip U7, the 1st pin of the voltage stabilizing chip U7, one end of the resistor R27, one end of the resistor R28 and the 3rd pin of the operational amplifier chip U5, the other end of the resistor R15 is electrically connected to one end of the resistor R17, the other end of the resistor R17 is electrically connected to one end of the capacitor C36 and grounded, the other end of the capacitor C36 is electrically connected to one end of the resistor R16, The other end of the resistor R16 is electrically connected to the pin 1 of the optocoupler chip U6, the other end of the capacitor C37 is electrically connected to the pin 2 of the voltage regulator chip U7 and grounded, the pin 4 of the op amp chip U5 is grounded, the other end of the resistor R28 is connected to the +12V voltage, the other end of the resistor R27 is electrically connected to the pin 1 of the op amp chip U5 and the pin 2 of the optocoupler chip U6, the pin 3 of the optocoupler chip U6 is grounded, and the pin 4 of the optocoupler chip U6 is electrically connected to one end of the resistor R18 and the G pin of the field effect tube Q1, respectively.The other end of the resistor R18 is connected to a +12V voltage; the energy storage C2 unit includes a resistor R38, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R49, a resistor R50, a resistor R51, a resistor R52, a capacitor C39, a capacitor C40, an operational amplifier chip U9, an optical coupler chip U10 and a voltage regulator chip U11, one end of the resistor R42 is electrically connected to one end of the resistor R43, and the other end of the resistor R43 is electrically connected to the resistor R44 One end of the resistor R44 is electrically connected to one end of the resistor R45, one end of the resistor R47 is electrically connected to one end of the resistor R48, the other end of the resistor R48 is electrically connected to one end of the resistor R49, the other end of the resistor R49 is electrically connected to one end of the resistor R50, the other end of the resistor R42 is electrically connected to the other end of the resistor R47 and is grounded, the other end of the resistor R45 is electrically connected to one end of the resistor R41 and pin 2 of the operational amplifier chip U9, respectively, and the other end of the resistor R50 is electrically connected to the One end of capacitor C40, pin 3 of voltage regulator chip U11, pin 1 of voltage regulator chip U11, one end of resistor R51, one end of resistor R52 and pin 3 of operational amplifier chip U9 are electrically connected, the other end of resistor R41 is electrically connected to one end of resistor R38, the other end of resistor R38 is electrically connected to one end of capacitor C39 and grounded, the other end of capacitor C39 is electrically connected to one end of resistor R40 and pin 5 of operational amplifier chip U9 and connected to +12V voltage, the other end of resistor R40 is electrically connected to pin 1 of optocoupler chip U10 The other end of the capacitor C40 is electrically connected to the 2nd pin of the voltage regulator chip U11 and grounded, the 4th pin of the operational amplifier chip U9 is grounded, the other end of the resistor R52 is connected to the +12V voltage, the other end of the resistor R51 is electrically connected to the 1st pin of the operational amplifier chip U9 and the 2nd pin of the optocoupler chip U10, the 3rd pin of the optocoupler chip U10 is grounded, the 4th pin of the optocoupler chip U10 is electrically connected to one end of the resistor R46 and the G pin of the field effect tube Q2, and the other end of the resistor R46 is connected to the +12V voltage; Control method: 1) When the load needs to be transferred from the mains side to the generator car for power supply, the main control unit MC1 controls the voltage sensor PT1 and the voltage sensor PT3 to monitor the mains voltage signal and the generator car voltage signal respectively. The main control unit MC1 determines whether the voltage phase sequence and phase of the incoming line side and the load side of the excitation transfer switch TSE1 are consistent by analyzing the mains voltage signal and the generator car voltage signal. If they are consistent, the main control unit MC1 will close the excitation transfer switch TSE1. At this time, the low-voltage circuit breaker in the low-voltage distribution box JP1 is manually disconnected, so that the load power supply circuit passes through the circuit breaker J1 and the circuit where the excitation transfer switch TSE1 is located; 2) At this time, the voltage sensor PT1 and the voltage sensor PT2 respectively monitor the voltage of the city power grid and the power generation vehicle in real time. Through the synchronization detection and phase difference change amount prediction of the main control unit MC1, combined with the action time characteristics of the excitation transfer switch TSE1 itself, the main control unit MC1 can predict the optimal time of the excitation coil drive command of the excitation transfer switch TSE2, so as to ensure that the contact closing time of the excitation transfer switch TSE2 and the phase difference of the city power grid are close to zero, that is, the excitation transfer switch TSE1 and the excitation transfer switch TSE2 are short-term connected in parallel to supply power to the load; 3) At this time, the main control unit MC1 will judge through the instantaneous current collected by the current sensor CT2, and calculate the time when the contacts of the excitation transfer switch TSE2 are closed; when the main control unit MC1 detects that the excitation transfer switch TSE2 is closed, the main control unit MC1 will immediately drive the excitation coil of the excitation transfer switch TSE1 to disconnect the contacts of the excitation transfer switch TSE1, and complete the load power supply conversion from the mains to the generator side without power outage; 4) After the excitation energy storage unit takes power from the generator side, it is used as the driving power supply for the excitation coils of the excitation conversion switch TSE1 and the excitation conversion switch TSE2 through rectification, boosting and constant voltage control. Through the constant voltage control of the energy storage unit and the constant pulse width drive control of the main control unit, the consistency of the excitation energy discharged at the driving moment is guaranteed, thereby ensuring the consistency and stability of the excitation conversion action characteristics and meeting the synchronous switching of the excitation conversion switch TSE1 and the excitation conversion switch TSE2.

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